Move core/fpdfapi/fpdf_parser to core/fpdfapi/parser

BUG=pdfium:603

Review-Url: https://codereview.chromium.org/2392603004

55 files changed, 12973 insertions, 0 deletions

diff --git a/core/fpdfapi/parser/cfdf_document.cpp b/core/fpdfapi/parser/cfdf_document.cpp
new file mode 100644
index 0000000000..a1518dfed0
--- /dev/null
+++ b/core/fpdfapi/parser/cfdf_document.cpp
@@ -0,0 +1,102 @@
+// Copyright 2014 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#include "core/fpdfapi/parser/cfdf_document.h"
+
+#include "core/fpdfapi/edit/cpdf_creator.h"
+#include "core/fpdfapi/parser/cpdf_dictionary.h"
+#include "core/fpdfapi/parser/cpdf_syntax_parser.h"
+#include "third_party/base/ptr_util.h"
+
+CFDF_Document::CFDF_Document()
+    : CPDF_IndirectObjectHolder(),
+      m_pRootDict(nullptr),
+      m_pFile(nullptr),
+      m_bOwnFile(FALSE),
+      m_pByteStringPool(pdfium::MakeUnique<CFX_ByteStringPool>()) {}
+
+CFDF_Document::~CFDF_Document() {
+  if (m_bOwnFile && m_pFile)
+    m_pFile->Release();
+  m_pByteStringPool.DeleteObject();  // Make weak.
+}
+
+CFDF_Document* CFDF_Document::CreateNewDoc() {
+  CFDF_Document* pDoc = new CFDF_Document;
+  pDoc->m_pRootDict = new CPDF_Dictionary(pDoc->GetByteStringPool());
+  pDoc->AddIndirectObject(pDoc->m_pRootDict);
+  pDoc->m_pRootDict->SetFor("FDF",
+                            new CPDF_Dictionary(pDoc->GetByteStringPool()));
+  return pDoc;
+}
+
+CFDF_Document* CFDF_Document::ParseFile(IFX_FileRead* pFile, FX_BOOL bOwnFile) {
+  if (!pFile)
+    return nullptr;
+
+  std::unique_ptr<CFDF_Document> pDoc(new CFDF_Document);
+  pDoc->ParseStream(pFile, bOwnFile);
+  return pDoc->m_pRootDict ? pDoc.release() : nullptr;
+}
+
+CFDF_Document* CFDF_Document::ParseMemory(const uint8_t* pData, uint32_t size) {
+  return CFDF_Document::ParseFile(FX_CreateMemoryStream((uint8_t*)pData, size),
+                                  TRUE);
+}
+
+void CFDF_Document::ParseStream(IFX_FileRead* pFile, FX_BOOL bOwnFile) {
+  m_pFile = pFile;
+  m_bOwnFile = bOwnFile;
+  CPDF_SyntaxParser parser;
+  parser.InitParser(m_pFile, 0);
+  while (1) {
+    bool bNumber;
+    CFX_ByteString word = parser.GetNextWord(&bNumber);
+    if (bNumber) {
+      uint32_t objnum = FXSYS_atoui(word.c_str());
+      word = parser.GetNextWord(&bNumber);
+      if (!bNumber)
+        break;
+
+      word = parser.GetNextWord(nullptr);
+      if (word != "obj")
+        break;
+
+      CPDF_Object* pObj = parser.GetObject(this, objnum, 0, true);
+      if (!pObj)
+        break;
+
+      ReplaceIndirectObjectIfHigherGeneration(objnum, pObj);
+      word = parser.GetNextWord(nullptr);
+      if (word != "endobj")
+        break;
+    } else {
+      if (word != "trailer")
+        break;
+
+      if (CPDF_Dictionary* pMainDict =
+              ToDictionary(parser.GetObject(this, 0, 0, true))) {
+        m_pRootDict = pMainDict->GetDictFor("Root");
+        pMainDict->Release();
+      }
+      break;
+    }
+  }
+}
+
+FX_BOOL CFDF_Document::WriteBuf(CFX_ByteTextBuf& buf) const {
+  if (!m_pRootDict)
+    return FALSE;
+
+  buf << "%FDF-1.2\r\n";
+  for (const auto& pair : *this)
+    buf << pair.first << " 0 obj\r\n"
+        << pair.second.get() << "\r\nendobj\r\n\r\n";
+
+  buf << "trailer\r\n<</Root " << m_pRootDict->GetObjNum()
+      << " 0 R>>\r\n%%EOF\r\n";
+  return TRUE;
+}
diff --git a/core/fpdfapi/parser/cfdf_document.h b/core/fpdfapi/parser/cfdf_document.h
new file mode 100644
index 0000000000..21ac62d11c
--- /dev/null
+++ b/core/fpdfapi/parser/cfdf_document.h
@@ -0,0 +1,42 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#ifndef CORE_FPDFAPI_PARSER_CFDF_DOCUMENT_H_
+#define CORE_FPDFAPI_PARSER_CFDF_DOCUMENT_H_
+
+#include "core/fpdfapi/parser/cpdf_indirect_object_holder.h"
+#include "core/fpdfapi/parser/cpdf_object.h"
+#include "core/fxcrt/cfx_string_pool_template.h"
+#include "core/fxcrt/cfx_weak_ptr.h"
+#include "core/fxcrt/fx_basic.h"
+
+class CPDF_Dictionary;
+
+class CFDF_Document : public CPDF_IndirectObjectHolder {
+ public:
+  static CFDF_Document* CreateNewDoc();
+  static CFDF_Document* ParseFile(IFX_FileRead* pFile,
+                                  FX_BOOL bOwnFile = FALSE);
+  static CFDF_Document* ParseMemory(const uint8_t* pData, uint32_t size);
+  ~CFDF_Document() override;
+
+  FX_BOOL WriteBuf(CFX_ByteTextBuf& buf) const;
+  CPDF_Dictionary* GetRoot() const { return m_pRootDict; }
+  CFX_WeakPtr<CFX_ByteStringPool> GetByteStringPool() const {
+    return m_pByteStringPool;
+  }
+
+ protected:
+  CFDF_Document();
+  void ParseStream(IFX_FileRead* pFile, FX_BOOL bOwnFile);
+
+  CPDF_Dictionary* m_pRootDict;
+  IFX_FileRead* m_pFile;
+  FX_BOOL m_bOwnFile;
+  CFX_WeakPtr<CFX_ByteStringPool> m_pByteStringPool;
+};
+
+#endif  // CORE_FPDFAPI_PARSER_CFDF_DOCUMENT_H_
diff --git a/core/fpdfapi/parser/cpdf_array.cpp b/core/fpdfapi/parser/cpdf_array.cpp
new file mode 100644
index 0000000000..61e69e8a53
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_array.cpp
@@ -0,0 +1,200 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#include "core/fpdfapi/parser/cpdf_array.h"
+
+#include <set>
+
+#include "core/fpdfapi/parser/cpdf_name.h"
+#include "core/fpdfapi/parser/cpdf_number.h"
+#include "core/fpdfapi/parser/cpdf_reference.h"
+#include "core/fpdfapi/parser/cpdf_stream.h"
+#include "core/fpdfapi/parser/cpdf_string.h"
+#include "third_party/base/logging.h"
+#include "third_party/base/stl_util.h"
+
+CPDF_Array::CPDF_Array() {}
+
+CPDF_Array::~CPDF_Array() {
+  // Mark the object as deleted so that it will not be deleted again
+  // in case of cyclic references.
+  m_ObjNum = kInvalidObjNum;
+  for (auto& it : m_Objects) {
+    if (it)
+      it->Release();
+  }
+}
+
+CPDF_Object::Type CPDF_Array::GetType() const {
+  return ARRAY;
+}
+
+bool CPDF_Array::IsArray() const {
+  return true;
+}
+
+CPDF_Array* CPDF_Array::AsArray() {
+  return this;
+}
+
+const CPDF_Array* CPDF_Array::AsArray() const {
+  return this;
+}
+
+CPDF_Object* CPDF_Array::Clone() const {
+  return CloneObjectNonCyclic(false);
+}
+
+CPDF_Object* CPDF_Array::CloneNonCyclic(
+    bool bDirect,
+    std::set<const CPDF_Object*>* pVisited) const {
+  pVisited->insert(this);
+  CPDF_Array* pCopy = new CPDF_Array();
+  for (size_t i = 0; i < GetCount(); i++) {
+    CPDF_Object* value = m_Objects[i];
+    if (!pdfium::ContainsKey(*pVisited, value))
+      pCopy->m_Objects.push_back(value->CloneNonCyclic(bDirect, pVisited));
+  }
+  return pCopy;
+}
+
+CFX_FloatRect CPDF_Array::GetRect() {
+  CFX_FloatRect rect;
+  if (!IsArray() || m_Objects.size() != 4)
+    return rect;
+
+  rect.left = GetNumberAt(0);
+  rect.bottom = GetNumberAt(1);
+  rect.right = GetNumberAt(2);
+  rect.top = GetNumberAt(3);
+  return rect;
+}
+
+CFX_Matrix CPDF_Array::GetMatrix() {
+  CFX_Matrix matrix;
+  if (!IsArray() || m_Objects.size() != 6)
+    return matrix;
+
+  matrix.Set(GetNumberAt(0), GetNumberAt(1), GetNumberAt(2), GetNumberAt(3),
+             GetNumberAt(4), GetNumberAt(5));
+  return matrix;
+}
+
+CPDF_Object* CPDF_Array::GetObjectAt(size_t i) const {
+  if (i >= m_Objects.size())
+    return nullptr;
+  return m_Objects[i];
+}
+
+CPDF_Object* CPDF_Array::GetDirectObjectAt(size_t i) const {
+  if (i >= m_Objects.size())
+    return nullptr;
+  return m_Objects[i]->GetDirect();
+}
+
+CFX_ByteString CPDF_Array::GetStringAt(size_t i) const {
+  if (i >= m_Objects.size())
+    return CFX_ByteString();
+  return m_Objects[i]->GetString();
+}
+
+int CPDF_Array::GetIntegerAt(size_t i) const {
+  if (i >= m_Objects.size())
+    return 0;
+  return m_Objects[i]->GetInteger();
+}
+
+FX_FLOAT CPDF_Array::GetNumberAt(size_t i) const {
+  if (i >= m_Objects.size())
+    return 0;
+  return m_Objects[i]->GetNumber();
+}
+
+CPDF_Dictionary* CPDF_Array::GetDictAt(size_t i) const {
+  CPDF_Object* p = GetDirectObjectAt(i);
+  if (!p)
+    return nullptr;
+  if (CPDF_Dictionary* pDict = p->AsDictionary())
+    return pDict;
+  if (CPDF_Stream* pStream = p->AsStream())
+    return pStream->GetDict();
+  return nullptr;
+}
+
+CPDF_Stream* CPDF_Array::GetStreamAt(size_t i) const {
+  return ToStream(GetDirectObjectAt(i));
+}
+
+CPDF_Array* CPDF_Array::GetArrayAt(size_t i) const {
+  return ToArray(GetDirectObjectAt(i));
+}
+
+void CPDF_Array::RemoveAt(size_t i, size_t nCount) {
+  if (i >= m_Objects.size())
+    return;
+
+  if (nCount <= 0 || nCount > m_Objects.size() - i)
+    return;
+
+  for (size_t j = 0; j < nCount; ++j) {
+    if (CPDF_Object* p = m_Objects[i + j])
+      p->Release();
+  }
+  m_Objects.erase(m_Objects.begin() + i, m_Objects.begin() + i + nCount);
+}
+
+void CPDF_Array::SetAt(size_t i, CPDF_Object* pObj) {
+  ASSERT(IsArray());
+  CHECK(!pObj || pObj->GetObjNum() == 0);
+  if (i >= m_Objects.size()) {
+    ASSERT(false);
+    return;
+  }
+  if (CPDF_Object* pOld = m_Objects[i])
+    pOld->Release();
+
+  m_Objects[i] = pObj;
+}
+
+void CPDF_Array::InsertAt(size_t index, CPDF_Object* pObj) {
+  ASSERT(IsArray());
+  CHECK(!pObj || pObj->GetObjNum() == 0);
+  if (index >= m_Objects.size()) {
+    // Allocate space first.
+    m_Objects.resize(index + 1, nullptr);
+    m_Objects[index] = pObj;
+  } else {
+    // Directly insert.
+    m_Objects.insert(m_Objects.begin() + index, pObj);
+  }
+}
+
+void CPDF_Array::Add(CPDF_Object* pObj) {
+  ASSERT(IsArray());
+  CHECK(!pObj || pObj->GetObjNum() == 0);
+  m_Objects.push_back(pObj);
+}
+
+void CPDF_Array::AddName(const CFX_ByteString& str) {
+  Add(new CPDF_Name(str));
+}
+
+void CPDF_Array::AddString(const CFX_ByteString& str) {
+  Add(new CPDF_String(str, FALSE));
+}
+
+void CPDF_Array::AddInteger(int i) {
+  Add(new CPDF_Number(i));
+}
+
+void CPDF_Array::AddNumber(FX_FLOAT f) {
+  Add(new CPDF_Number(f));
+}
+
+void CPDF_Array::AddReference(CPDF_IndirectObjectHolder* pDoc,
+                              uint32_t objnum) {
+  Add(new CPDF_Reference(pDoc, objnum));
+}
diff --git a/core/fpdfapi/parser/cpdf_array.h b/core/fpdfapi/parser/cpdf_array.h
new file mode 100644
index 0000000000..25bbdd56f2
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_array.h
@@ -0,0 +1,72 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#ifndef CORE_FPDFAPI_PARSER_CPDF_ARRAY_H_
+#define CORE_FPDFAPI_PARSER_CPDF_ARRAY_H_
+
+#include <set>
+#include <vector>
+
+#include "core/fpdfapi/parser/cpdf_indirect_object_holder.h"
+#include "core/fpdfapi/parser/cpdf_object.h"
+#include "core/fxcrt/fx_basic.h"
+#include "core/fxcrt/fx_coordinates.h"
+
+class CPDF_Array : public CPDF_Object {
+ public:
+  using iterator = std::vector<CPDF_Object*>::iterator;
+  using const_iterator = std::vector<CPDF_Object*>::const_iterator;
+
+  CPDF_Array();
+
+  // CPDF_Object.
+  Type GetType() const override;
+  CPDF_Object* Clone() const override;
+  bool IsArray() const override;
+  CPDF_Array* AsArray() override;
+  const CPDF_Array* AsArray() const override;
+
+  bool IsEmpty() const { return m_Objects.empty(); }
+  size_t GetCount() const { return m_Objects.size(); }
+  CPDF_Object* GetObjectAt(size_t index) const;
+  CPDF_Object* GetDirectObjectAt(size_t index) const;
+  CFX_ByteString GetStringAt(size_t index) const;
+  int GetIntegerAt(size_t index) const;
+  FX_FLOAT GetNumberAt(size_t index) const;
+  CPDF_Dictionary* GetDictAt(size_t index) const;
+  CPDF_Stream* GetStreamAt(size_t index) const;
+  CPDF_Array* GetArrayAt(size_t index) const;
+  FX_FLOAT GetFloatAt(size_t index) const { return GetNumberAt(index); }
+  CFX_Matrix GetMatrix();
+  CFX_FloatRect GetRect();
+
+  void SetAt(size_t index, CPDF_Object* pObj);
+  void InsertAt(size_t index, CPDF_Object* pObj);
+  void RemoveAt(size_t index, size_t nCount = 1);
+
+  void Add(CPDF_Object* pObj);
+  void AddNumber(FX_FLOAT f);
+  void AddInteger(int i);
+  void AddString(const CFX_ByteString& str);
+  void AddName(const CFX_ByteString& str);
+  void AddReference(CPDF_IndirectObjectHolder* pDoc, uint32_t objnum);
+
+  iterator begin() { return m_Objects.begin(); }
+  iterator end() { return m_Objects.end(); }
+  const_iterator begin() const { return m_Objects.begin(); }
+  const_iterator end() const { return m_Objects.end(); }
+
+ protected:
+  ~CPDF_Array() override;
+
+  CPDF_Object* CloneNonCyclic(
+      bool bDirect,
+      std::set<const CPDF_Object*>* pVisited) const override;
+
+  std::vector<CPDF_Object*> m_Objects;
+};
+
+#endif  // CORE_FPDFAPI_PARSER_CPDF_ARRAY_H_
diff --git a/core/fpdfapi/parser/cpdf_array_unittest.cpp b/core/fpdfapi/parser/cpdf_array_unittest.cpp
new file mode 100644
index 0000000000..bc9f578021
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_array_unittest.cpp
@@ -0,0 +1,180 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "core/fpdfapi/parser/cpdf_array.h"
+#include "core/fpdfapi/parser/cpdf_number.h"
+#include "core/fpdfapi/parser/cpdf_reference.h"
+
+#include <memory>
+
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace {
+
+using ScopedArray = std::unique_ptr<CPDF_Array, ReleaseDeleter<CPDF_Array>>;
+
+}  // namespace
+
+TEST(cpdf_array, RemoveAt) {
+  {
+    int elems[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
+    ScopedArray arr(new CPDF_Array);
+    for (size_t i = 0; i < FX_ArraySize(elems); ++i)
+      arr->AddInteger(elems[i]);
+    arr->RemoveAt(3, 3);
+    int expected[] = {1, 2, 3, 7, 8, 9, 10};
+    EXPECT_EQ(FX_ArraySize(expected), arr->GetCount());
+    for (size_t i = 0; i < FX_ArraySize(expected); ++i)
+      EXPECT_EQ(expected[i], arr->GetIntegerAt(i));
+    arr->RemoveAt(4, 2);
+    int expected2[] = {1, 2, 3, 7, 10};
+    EXPECT_EQ(FX_ArraySize(expected2), arr->GetCount());
+    for (size_t i = 0; i < FX_ArraySize(expected2); ++i)
+      EXPECT_EQ(expected2[i], arr->GetIntegerAt(i));
+  }
+  {
+    // When the range is out of bound, RemoveAt has no effect.
+    int elems[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
+    ScopedArray arr(new CPDF_Array);
+    for (size_t i = 0; i < FX_ArraySize(elems); ++i)
+      arr->AddInteger(elems[i]);
+    arr->RemoveAt(8, 5);
+    EXPECT_EQ(FX_ArraySize(elems), arr->GetCount());
+    for (size_t i = 0; i < FX_ArraySize(elems); ++i)
+      EXPECT_EQ(elems[i], arr->GetIntegerAt(i));
+    arr->RemoveAt(0, 12);
+    EXPECT_EQ(FX_ArraySize(elems), arr->GetCount());
+    arr->RemoveAt(11, 1);
+    EXPECT_EQ(FX_ArraySize(elems), arr->GetCount());
+  }
+}
+
+TEST(cpdf_array, InsertAt) {
+  {
+    int elems[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
+    ScopedArray arr(new CPDF_Array);
+    for (size_t i = 0; i < FX_ArraySize(elems); ++i)
+      arr->InsertAt(i, new CPDF_Number(elems[i]));
+    EXPECT_EQ(FX_ArraySize(elems), arr->GetCount());
+    for (size_t i = 0; i < FX_ArraySize(elems); ++i)
+      EXPECT_EQ(elems[i], arr->GetIntegerAt(i));
+    arr->InsertAt(3, new CPDF_Number(33));
+    arr->InsertAt(6, new CPDF_Number(55));
+    arr->InsertAt(12, new CPDF_Number(12));
+    int expected[] = {1, 2, 3, 33, 4, 5, 55, 6, 7, 8, 9, 10, 12};
+    EXPECT_EQ(FX_ArraySize(expected), arr->GetCount());
+    for (size_t i = 0; i < FX_ArraySize(expected); ++i)
+      EXPECT_EQ(expected[i], arr->GetIntegerAt(i));
+  }
+  {
+    // When the position to insert is beyond the upper bound,
+    // an element is inserted at that position while other unfilled
+    // positions have nullptr.
+    int elems[] = {1, 2};
+    ScopedArray arr(new CPDF_Array);
+    for (size_t i = 0; i < FX_ArraySize(elems); ++i)
+      arr->InsertAt(i, new CPDF_Number(elems[i]));
+    arr->InsertAt(10, new CPDF_Number(10));
+    EXPECT_EQ(11u, arr->GetCount());
+    for (size_t i = 0; i < FX_ArraySize(elems); ++i)
+      EXPECT_EQ(elems[i], arr->GetIntegerAt(i));
+    for (size_t i = FX_ArraySize(elems); i < 10; ++i)
+      EXPECT_EQ(nullptr, arr->GetObjectAt(i));
+    EXPECT_EQ(10, arr->GetIntegerAt(10));
+  }
+}
+
+TEST(cpdf_array, Clone) {
+  {
+    // Basic case.
+    int elems[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
+    ScopedArray arr(new CPDF_Array);
+    for (size_t i = 0; i < FX_ArraySize(elems); ++i)
+      arr->InsertAt(i, new CPDF_Number(elems[i]));
+    ScopedArray arr2(arr->Clone()->AsArray());
+    EXPECT_EQ(arr->GetCount(), arr2->GetCount());
+    for (size_t i = 0; i < FX_ArraySize(elems); ++i) {
+      // Clone() always create new objects.
+      EXPECT_NE(arr->GetObjectAt(i), arr2->GetObjectAt(i));
+      EXPECT_EQ(arr->GetIntegerAt(i), arr2->GetIntegerAt(i));
+    }
+  }
+  {
+    // Clone() with and without dereferencing reference objects.
+    static const size_t kNumOfRows = 3;
+    static const size_t kNumOfRowElems = 5;
+    int elems[kNumOfRows][kNumOfRowElems] = {
+        {1, 2, 3, 4, 5}, {10, 9, 8, 7, 6}, {11, 12, 13, 14, 15}};
+    ScopedArray arr(new CPDF_Array);
+    // Indirect references to indirect objects.
+    std::unique_ptr<CPDF_IndirectObjectHolder> obj_holder(
+        new CPDF_IndirectObjectHolder());
+    for (size_t i = 0; i < kNumOfRows; ++i) {
+      CPDF_Array* arr_elem = new CPDF_Array;
+      for (size_t j = 0; j < kNumOfRowElems; ++j) {
+        CPDF_Number* obj = new CPDF_Number(elems[i][j]);
+        // Starts object number from 1.
+        int obj_num = i * kNumOfRowElems + j + 1;
+        obj_holder->ReplaceIndirectObjectIfHigherGeneration(obj_num, obj);
+        arr_elem->InsertAt(j, new CPDF_Reference(obj_holder.get(), obj_num));
+      }
+      arr->InsertAt(i, arr_elem);
+    }
+    ASSERT_EQ(kNumOfRows, arr->GetCount());
+    // Not dereferencing reference objects means just creating new references
+    // instead of new copies of direct objects.
+    ScopedArray arr1(arr->Clone()->AsArray());
+    EXPECT_EQ(arr->GetCount(), arr1->GetCount());
+    // Dereferencing reference objects creates new copies of direct objects.
+    ScopedArray arr2(arr->CloneDirectObject()->AsArray());
+    EXPECT_EQ(arr->GetCount(), arr2->GetCount());
+    for (size_t i = 0; i < kNumOfRows; ++i) {
+      CPDF_Array* arr_elem = arr->GetObjectAt(i)->AsArray();
+      CPDF_Array* arr1_elem = arr1->GetObjectAt(i)->AsArray();
+      CPDF_Array* arr2_elem = arr2->GetObjectAt(i)->AsArray();
+      EXPECT_NE(arr_elem, arr1_elem);
+      EXPECT_NE(arr_elem, arr2_elem);
+      for (size_t j = 0; j < kNumOfRowElems; ++j) {
+        auto elem_obj = arr_elem->GetObjectAt(j);
+        auto elem_obj1 = arr1_elem->GetObjectAt(j);
+        auto elem_obj2 = arr2_elem->GetObjectAt(j);
+        // Results from not deferencing reference objects.
+        EXPECT_NE(elem_obj, elem_obj1);
+        EXPECT_TRUE(elem_obj1->IsReference());
+        EXPECT_EQ(elem_obj->GetDirect(), elem_obj1->GetDirect());
+        EXPECT_EQ(elem_obj->GetInteger(), elem_obj1->GetInteger());
+        // Results from deferencing reference objects.
+        EXPECT_NE(elem_obj, elem_obj2);
+        EXPECT_TRUE(elem_obj2->IsNumber());
+        EXPECT_NE(elem_obj->GetDirect(), elem_obj2);
+        EXPECT_EQ(elem_obj->GetObjNum(), elem_obj2->GetObjNum());
+        EXPECT_EQ(elem_obj->GetInteger(), elem_obj2->GetInteger());
+      }
+    }
+    arr.reset();
+    ASSERT_EQ(kNumOfRows, arr1->GetCount());
+    for (size_t i = 0; i < kNumOfRows; ++i) {
+      for (size_t j = 0; j < kNumOfRowElems; ++j) {
+        // Results from not deferencing reference objects.
+        auto elem_obj1 = arr1->GetObjectAt(i)->AsArray()->GetObjectAt(j);
+        EXPECT_TRUE(elem_obj1->IsReference());
+        EXPECT_EQ(elems[i][j], elem_obj1->GetInteger());
+        // Results from deferencing reference objects.
+        EXPECT_EQ(elems[i][j],
+                  arr2->GetObjectAt(i)->AsArray()->GetIntegerAt(j));
+      }
+    }
+  }
+}
+
+TEST(cpdf_array, Iterator) {
+  int elems[] = {-23, -11,     3,         455,   2345877,
+                 0,   7895330, -12564334, 10000, -100000};
+  ScopedArray arr(new CPDF_Array);
+  for (size_t i = 0; i < FX_ArraySize(elems); ++i)
+    arr->InsertAt(i, new CPDF_Number(elems[i]));
+  size_t index = 0;
+  for (const auto& it : *arr)
+    EXPECT_EQ(elems[index++], it->AsNumber()->GetInteger());
+}
diff --git a/core/fpdfapi/parser/cpdf_boolean.cpp b/core/fpdfapi/parser/cpdf_boolean.cpp
new file mode 100644
index 0000000000..416b6ff4bc
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_boolean.cpp
@@ -0,0 +1,45 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#include "core/fpdfapi/parser/cpdf_boolean.h"
+
+CPDF_Boolean::CPDF_Boolean() : m_bValue(false) {}
+
+CPDF_Boolean::CPDF_Boolean(bool value) : m_bValue(value) {}
+
+CPDF_Boolean::~CPDF_Boolean() {}
+
+CPDF_Object::Type CPDF_Boolean::GetType() const {
+  return BOOLEAN;
+}
+
+CPDF_Object* CPDF_Boolean::Clone() const {
+  return new CPDF_Boolean(m_bValue);
+}
+
+CFX_ByteString CPDF_Boolean::GetString() const {
+  return m_bValue ? "true" : "false";
+}
+
+int CPDF_Boolean::GetInteger() const {
+  return m_bValue;
+}
+
+void CPDF_Boolean::SetString(const CFX_ByteString& str) {
+  m_bValue = (str == "true");
+}
+
+bool CPDF_Boolean::IsBoolean() const {
+  return true;
+}
+
+CPDF_Boolean* CPDF_Boolean::AsBoolean() {
+  return this;
+}
+
+const CPDF_Boolean* CPDF_Boolean::AsBoolean() const {
+  return this;
+}
diff --git a/core/fpdfapi/parser/cpdf_boolean.h b/core/fpdfapi/parser/cpdf_boolean.h
new file mode 100644
index 0000000000..89ed17d743
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_boolean.h
@@ -0,0 +1,35 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#ifndef CORE_FPDFAPI_PARSER_CPDF_BOOLEAN_H_
+#define CORE_FPDFAPI_PARSER_CPDF_BOOLEAN_H_
+
+#include "core/fpdfapi/parser/cpdf_object.h"
+#include "core/fxcrt/fx_string.h"
+#include "core/fxcrt/fx_system.h"
+
+class CPDF_Boolean : public CPDF_Object {
+ public:
+  CPDF_Boolean();
+  explicit CPDF_Boolean(bool value);
+
+  // CPDF_Object.
+  Type GetType() const override;
+  CPDF_Object* Clone() const override;
+  CFX_ByteString GetString() const override;
+  int GetInteger() const override;
+  void SetString(const CFX_ByteString& str) override;
+  bool IsBoolean() const override;
+  CPDF_Boolean* AsBoolean() override;
+  const CPDF_Boolean* AsBoolean() const override;
+
+ protected:
+  ~CPDF_Boolean() override;
+
+  bool m_bValue;
+};
+
+#endif  // CORE_FPDFAPI_PARSER_CPDF_BOOLEAN_H_
diff --git a/core/fpdfapi/parser/cpdf_crypto_handler.cpp b/core/fpdfapi/parser/cpdf_crypto_handler.cpp
new file mode 100644
index 0000000000..f7dc19e243
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_crypto_handler.cpp
@@ -0,0 +1,342 @@
+// Copyright 2014 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#include "core/fpdfapi/parser/cpdf_crypto_handler.h"
+
+#include <time.h>
+
+#include "core/fdrm/crypto/fx_crypt.h"
+#include "core/fpdfapi/parser/cpdf_parser.h"
+#include "core/fpdfapi/parser/cpdf_security_handler.h"
+#include "core/fpdfapi/parser/cpdf_simple_parser.h"
+
+void CPDF_CryptoHandler::CryptBlock(FX_BOOL bEncrypt,
+                                    uint32_t objnum,
+                                    uint32_t gennum,
+                                    const uint8_t* src_buf,
+                                    uint32_t src_size,
+                                    uint8_t* dest_buf,
+                                    uint32_t& dest_size) {
+  if (m_Cipher == FXCIPHER_NONE) {
+    FXSYS_memcpy(dest_buf, src_buf, src_size);
+    return;
+  }
+  uint8_t realkey[16];
+  int realkeylen = 16;
+  if (m_Cipher != FXCIPHER_AES || m_KeyLen != 32) {
+    uint8_t key1[32];
+    PopulateKey(objnum, gennum, key1);
+
+    if (m_Cipher == FXCIPHER_AES) {
+      FXSYS_memcpy(key1 + m_KeyLen + 5, "sAlT", 4);
+    }
+    CRYPT_MD5Generate(
+        key1, m_Cipher == FXCIPHER_AES ? m_KeyLen + 9 : m_KeyLen + 5, realkey);
+    realkeylen = m_KeyLen + 5;
+    if (realkeylen > 16) {
+      realkeylen = 16;
+    }
+  }
+  if (m_Cipher == FXCIPHER_AES) {
+    CRYPT_AESSetKey(m_pAESContext, 16, m_KeyLen == 32 ? m_EncryptKey : realkey,
+                    m_KeyLen, bEncrypt);
+    if (bEncrypt) {
+      uint8_t iv[16];
+      for (int i = 0; i < 16; i++) {
+        iv[i] = (uint8_t)rand();
+      }
+      CRYPT_AESSetIV(m_pAESContext, iv);
+      FXSYS_memcpy(dest_buf, iv, 16);
+      int nblocks = src_size / 16;
+      CRYPT_AESEncrypt(m_pAESContext, dest_buf + 16, src_buf, nblocks * 16);
+      uint8_t padding[16];
+      FXSYS_memcpy(padding, src_buf + nblocks * 16, src_size % 16);
+      FXSYS_memset(padding + src_size % 16, 16 - src_size % 16,
+                   16 - src_size % 16);
+      CRYPT_AESEncrypt(m_pAESContext, dest_buf + nblocks * 16 + 16, padding,
+                       16);
+      dest_size = 32 + nblocks * 16;
+    } else {
+      CRYPT_AESSetIV(m_pAESContext, src_buf);
+      CRYPT_AESDecrypt(m_pAESContext, dest_buf, src_buf + 16, src_size - 16);
+      dest_size = src_size - 16;
+      dest_size -= dest_buf[dest_size - 1];
+    }
+  } else {
+    ASSERT(dest_size == src_size);
+    if (dest_buf != src_buf) {
+      FXSYS_memcpy(dest_buf, src_buf, src_size);
+    }
+    CRYPT_ArcFourCryptBlock(dest_buf, dest_size, realkey, realkeylen);
+  }
+}
+
+struct AESCryptContext {
+  uint8_t m_Context[2048];
+  FX_BOOL m_bIV;
+  uint8_t m_Block[16];
+  uint32_t m_BlockOffset;
+};
+
+void* CPDF_CryptoHandler::CryptStart(uint32_t objnum,
+                                     uint32_t gennum,
+                                     FX_BOOL bEncrypt) {
+  if (m_Cipher == FXCIPHER_NONE) {
+    return this;
+  }
+  if (m_Cipher == FXCIPHER_AES && m_KeyLen == 32) {
+    AESCryptContext* pContext = FX_Alloc(AESCryptContext, 1);
+    pContext->m_bIV = TRUE;
+    pContext->m_BlockOffset = 0;
+    CRYPT_AESSetKey(pContext->m_Context, 16, m_EncryptKey, 32, bEncrypt);
+    if (bEncrypt) {
+      for (int i = 0; i < 16; i++) {
+        pContext->m_Block[i] = (uint8_t)rand();
+      }
+      CRYPT_AESSetIV(pContext->m_Context, pContext->m_Block);
+    }
+    return pContext;
+  }
+  uint8_t key1[48];
+  PopulateKey(objnum, gennum, key1);
+
+  if (m_Cipher == FXCIPHER_AES) {
+    FXSYS_memcpy(key1 + m_KeyLen + 5, "sAlT", 4);
+  }
+  uint8_t realkey[16];
+  CRYPT_MD5Generate(
+      key1, m_Cipher == FXCIPHER_AES ? m_KeyLen + 9 : m_KeyLen + 5, realkey);
+  int realkeylen = m_KeyLen + 5;
+  if (realkeylen > 16) {
+    realkeylen = 16;
+  }
+  if (m_Cipher == FXCIPHER_AES) {
+    AESCryptContext* pContext = FX_Alloc(AESCryptContext, 1);
+    pContext->m_bIV = TRUE;
+    pContext->m_BlockOffset = 0;
+    CRYPT_AESSetKey(pContext->m_Context, 16, realkey, 16, bEncrypt);
+    if (bEncrypt) {
+      for (int i = 0; i < 16; i++) {
+        pContext->m_Block[i] = (uint8_t)rand();
+      }
+      CRYPT_AESSetIV(pContext->m_Context, pContext->m_Block);
+    }
+    return pContext;
+  }
+  void* pContext = FX_Alloc(uint8_t, 1040);
+  CRYPT_ArcFourSetup(pContext, realkey, realkeylen);
+  return pContext;
+}
+
+FX_BOOL CPDF_CryptoHandler::CryptStream(void* context,
+                                        const uint8_t* src_buf,
+                                        uint32_t src_size,
+                                        CFX_BinaryBuf& dest_buf,
+                                        FX_BOOL bEncrypt) {
+  if (!context) {
+    return FALSE;
+  }
+  if (m_Cipher == FXCIPHER_NONE) {
+    dest_buf.AppendBlock(src_buf, src_size);
+    return TRUE;
+  }
+  if (m_Cipher == FXCIPHER_RC4) {
+    int old_size = dest_buf.GetSize();
+    dest_buf.AppendBlock(src_buf, src_size);
+    CRYPT_ArcFourCrypt(context, dest_buf.GetBuffer() + old_size, src_size);
+    return TRUE;
+  }
+  AESCryptContext* pContext = (AESCryptContext*)context;
+  if (pContext->m_bIV && bEncrypt) {
+    dest_buf.AppendBlock(pContext->m_Block, 16);
+    pContext->m_bIV = FALSE;
+  }
+  uint32_t src_off = 0;
+  uint32_t src_left = src_size;
+  while (1) {
+    uint32_t copy_size = 16 - pContext->m_BlockOffset;
+    if (copy_size > src_left) {
+      copy_size = src_left;
+    }
+    FXSYS_memcpy(pContext->m_Block + pContext->m_BlockOffset, src_buf + src_off,
+                 copy_size);
+    src_off += copy_size;
+    src_left -= copy_size;
+    pContext->m_BlockOffset += copy_size;
+    if (pContext->m_BlockOffset == 16) {
+      if (!bEncrypt && pContext->m_bIV) {
+        CRYPT_AESSetIV(pContext->m_Context, pContext->m_Block);
+        pContext->m_bIV = FALSE;
+        pContext->m_BlockOffset = 0;
+      } else if (src_off < src_size) {
+        uint8_t block_buf[16];
+        if (bEncrypt) {
+          CRYPT_AESEncrypt(pContext->m_Context, block_buf, pContext->m_Block,
+                           16);
+        } else {
+          CRYPT_AESDecrypt(pContext->m_Context, block_buf, pContext->m_Block,
+                           16);
+        }
+        dest_buf.AppendBlock(block_buf, 16);
+        pContext->m_BlockOffset = 0;
+      }
+    }
+    if (!src_left) {
+      break;
+    }
+  }
+  return TRUE;
+}
+FX_BOOL CPDF_CryptoHandler::CryptFinish(void* context,
+                                        CFX_BinaryBuf& dest_buf,
+                                        FX_BOOL bEncrypt) {
+  if (!context) {
+    return FALSE;
+  }
+  if (m_Cipher == FXCIPHER_NONE) {
+    return TRUE;
+  }
+  if (m_Cipher == FXCIPHER_RC4) {
+    FX_Free(context);
+    return TRUE;
+  }
+  AESCryptContext* pContext = (AESCryptContext*)context;
+  if (bEncrypt) {
+    uint8_t block_buf[16];
+    if (pContext->m_BlockOffset == 16) {
+      CRYPT_AESEncrypt(pContext->m_Context, block_buf, pContext->m_Block, 16);
+      dest_buf.AppendBlock(block_buf, 16);
+      pContext->m_BlockOffset = 0;
+    }
+    FXSYS_memset(pContext->m_Block + pContext->m_BlockOffset,
+                 (uint8_t)(16 - pContext->m_BlockOffset),
+                 16 - pContext->m_BlockOffset);
+    CRYPT_AESEncrypt(pContext->m_Context, block_buf, pContext->m_Block, 16);
+    dest_buf.AppendBlock(block_buf, 16);
+  } else if (pContext->m_BlockOffset == 16) {
+    uint8_t block_buf[16];
+    CRYPT_AESDecrypt(pContext->m_Context, block_buf, pContext->m_Block, 16);
+    if (block_buf[15] <= 16) {
+      dest_buf.AppendBlock(block_buf, 16 - block_buf[15]);
+    }
+  }
+  FX_Free(pContext);
+  return TRUE;
+}
+
+void CPDF_CryptoHandler::Decrypt(uint32_t objnum,
+                                 uint32_t gennum,
+                                 CFX_ByteString& str) {
+  CFX_BinaryBuf dest_buf;
+  void* context = DecryptStart(objnum, gennum);
+  DecryptStream(context, str.raw_str(), str.GetLength(), dest_buf);
+  DecryptFinish(context, dest_buf);
+  str = CFX_ByteString(dest_buf.GetBuffer(), dest_buf.GetSize());
+}
+
+void* CPDF_CryptoHandler::DecryptStart(uint32_t objnum, uint32_t gennum) {
+  return CryptStart(objnum, gennum, FALSE);
+}
+uint32_t CPDF_CryptoHandler::DecryptGetSize(uint32_t src_size) {
+  return m_Cipher == FXCIPHER_AES ? src_size - 16 : src_size;
+}
+
+FX_BOOL CPDF_CryptoHandler::Init(CPDF_Dictionary* pEncryptDict,
+                                 CPDF_SecurityHandler* pSecurityHandler) {
+  const uint8_t* key;
+  if (!pSecurityHandler->GetCryptInfo(m_Cipher, key, m_KeyLen)) {
+    return FALSE;
+  }
+  if (m_KeyLen > 32 || m_KeyLen < 0) {
+    return FALSE;
+  }
+  if (m_Cipher != FXCIPHER_NONE) {
+    FXSYS_memcpy(m_EncryptKey, key, m_KeyLen);
+  }
+  if (m_Cipher == FXCIPHER_AES) {
+    m_pAESContext = FX_Alloc(uint8_t, 2048);
+  }
+  return TRUE;
+}
+
+FX_BOOL CPDF_CryptoHandler::Init(int cipher, const uint8_t* key, int keylen) {
+  if (cipher == FXCIPHER_AES) {
+    switch (keylen) {
+      case 16:
+      case 24:
+      case 32:
+        break;
+      default:
+        return FALSE;
+    }
+  } else if (cipher == FXCIPHER_AES2) {
+    if (keylen != 32) {
+      return FALSE;
+    }
+  } else if (cipher == FXCIPHER_RC4) {
+    if (keylen < 5 || keylen > 16) {
+      return FALSE;
+    }
+  } else {
+    if (keylen > 32) {
+      keylen = 32;
+    }
+  }
+  m_Cipher = cipher;
+  m_KeyLen = keylen;
+  FXSYS_memcpy(m_EncryptKey, key, keylen);
+  if (m_Cipher == FXCIPHER_AES) {
+    m_pAESContext = FX_Alloc(uint8_t, 2048);
+  }
+  return TRUE;
+}
+FX_BOOL CPDF_CryptoHandler::DecryptStream(void* context,
+                                          const uint8_t* src_buf,
+                                          uint32_t src_size,
+                                          CFX_BinaryBuf& dest_buf) {
+  return CryptStream(context, src_buf, src_size, dest_buf, FALSE);
+}
+FX_BOOL CPDF_CryptoHandler::DecryptFinish(void* context,
+                                          CFX_BinaryBuf& dest_buf) {
+  return CryptFinish(context, dest_buf, FALSE);
+}
+uint32_t CPDF_CryptoHandler::EncryptGetSize(uint32_t objnum,
+                                            uint32_t version,
+                                            const uint8_t* src_buf,
+                                            uint32_t src_size) {
+  if (m_Cipher == FXCIPHER_AES) {
+    return src_size + 32;
+  }
+  return src_size;
+}
+FX_BOOL CPDF_CryptoHandler::EncryptContent(uint32_t objnum,
+                                           uint32_t gennum,
+                                           const uint8_t* src_buf,
+                                           uint32_t src_size,
+                                           uint8_t* dest_buf,
+                                           uint32_t& dest_size) {
+  CryptBlock(TRUE, objnum, gennum, src_buf, src_size, dest_buf, dest_size);
+  return TRUE;
+}
+CPDF_CryptoHandler::CPDF_CryptoHandler() {
+  m_pAESContext = nullptr;
+  m_Cipher = FXCIPHER_NONE;
+  m_KeyLen = 0;
+}
+CPDF_CryptoHandler::~CPDF_CryptoHandler() {
+  FX_Free(m_pAESContext);
+}
+
+void CPDF_CryptoHandler::PopulateKey(uint32_t objnum,
+                                     uint32_t gennum,
+                                     uint8_t* key) {
+  FXSYS_memcpy(key, m_EncryptKey, m_KeyLen);
+  key[m_KeyLen + 0] = (uint8_t)objnum;
+  key[m_KeyLen + 1] = (uint8_t)(objnum >> 8);
+  key[m_KeyLen + 2] = (uint8_t)(objnum >> 16);
+  key[m_KeyLen + 3] = (uint8_t)gennum;
+  key[m_KeyLen + 4] = (uint8_t)(gennum >> 8);
+}
diff --git a/core/fpdfapi/parser/cpdf_crypto_handler.h b/core/fpdfapi/parser/cpdf_crypto_handler.h
new file mode 100644
index 0000000000..37612f9ef0
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_crypto_handler.h
@@ -0,0 +1,70 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#ifndef CORE_FPDFAPI_PARSER_CPDF_CRYPTO_HANDLER_H_
+#define CORE_FPDFAPI_PARSER_CPDF_CRYPTO_HANDLER_H_
+
+#include "core/fxcrt/fx_basic.h"
+#include "core/fxcrt/fx_string.h"
+#include "core/fxcrt/fx_system.h"
+
+class CPDF_Dictionary;
+class CPDF_SecurityHandler;
+
+class CPDF_CryptoHandler {
+ public:
+  CPDF_CryptoHandler();
+  ~CPDF_CryptoHandler();
+
+  FX_BOOL Init(CPDF_Dictionary* pEncryptDict,
+               CPDF_SecurityHandler* pSecurityHandler);
+  uint32_t DecryptGetSize(uint32_t src_size);
+  void* DecryptStart(uint32_t objnum, uint32_t gennum);
+  void Decrypt(uint32_t objnum, uint32_t gennum, CFX_ByteString& str);
+  FX_BOOL DecryptStream(void* context,
+                        const uint8_t* src_buf,
+                        uint32_t src_size,
+                        CFX_BinaryBuf& dest_buf);
+  FX_BOOL DecryptFinish(void* context, CFX_BinaryBuf& dest_buf);
+  uint32_t EncryptGetSize(uint32_t objnum,
+                          uint32_t version,
+                          const uint8_t* src_buf,
+                          uint32_t src_size);
+  FX_BOOL EncryptContent(uint32_t objnum,
+                         uint32_t version,
+                         const uint8_t* src_buf,
+                         uint32_t src_size,
+                         uint8_t* dest_buf,
+                         uint32_t& dest_size);
+
+  FX_BOOL Init(int cipher, const uint8_t* key, int keylen);
+
+ protected:
+  void CryptBlock(FX_BOOL bEncrypt,
+                  uint32_t objnum,
+                  uint32_t gennum,
+                  const uint8_t* src_buf,
+                  uint32_t src_size,
+                  uint8_t* dest_buf,
+                  uint32_t& dest_size);
+  void* CryptStart(uint32_t objnum, uint32_t gennum, FX_BOOL bEncrypt);
+  FX_BOOL CryptStream(void* context,
+                      const uint8_t* src_buf,
+                      uint32_t src_size,
+                      CFX_BinaryBuf& dest_buf,
+                      FX_BOOL bEncrypt);
+  FX_BOOL CryptFinish(void* context, CFX_BinaryBuf& dest_buf, FX_BOOL bEncrypt);
+
+  uint8_t m_EncryptKey[32];
+  int m_KeyLen;
+  int m_Cipher;
+  uint8_t* m_pAESContext;
+
+ private:
+  void PopulateKey(uint32_t objnum, uint32_t gennum, uint8_t* key);
+};
+
+#endif  // CORE_FPDFAPI_PARSER_CPDF_CRYPTO_HANDLER_H_
diff --git a/core/fpdfapi/parser/cpdf_data_avail.cpp b/core/fpdfapi/parser/cpdf_data_avail.cpp
new file mode 100644
index 0000000000..da7f6948a3
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_data_avail.cpp
@@ -0,0 +1,1844 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#include "core/fpdfapi/parser/cpdf_data_avail.h"
+
+#include <algorithm>
+#include <memory>
+#include <utility>
+
+#include "core/fpdfapi/cpdf_modulemgr.h"
+#include "core/fpdfapi/parser/cpdf_array.h"
+#include "core/fpdfapi/parser/cpdf_dictionary.h"
+#include "core/fpdfapi/parser/cpdf_document.h"
+#include "core/fpdfapi/parser/cpdf_hint_tables.h"
+#include "core/fpdfapi/parser/cpdf_name.h"
+#include "core/fpdfapi/parser/cpdf_number.h"
+#include "core/fpdfapi/parser/cpdf_reference.h"
+#include "core/fpdfapi/parser/cpdf_stream.h"
+#include "core/fpdfapi/parser/fpdf_parser_utility.h"
+#include "core/fxcrt/fx_ext.h"
+#include "core/fxcrt/fx_safe_types.h"
+#include "third_party/base/stl_util.h"
+
+CPDF_DataAvail::FileAvail::~FileAvail() {}
+
+CPDF_DataAvail::DownloadHints::~DownloadHints() {}
+
+// static
+int CPDF_DataAvail::s_CurrentDataAvailRecursionDepth = 0;
+
+CPDF_DataAvail::CPDF_DataAvail(FileAvail* pFileAvail,
+                               IFX_FileRead* pFileRead,
+                               FX_BOOL bSupportHintTable)
+    : m_pFileAvail(pFileAvail), m_pFileRead(pFileRead) {
+  m_Pos = 0;
+  m_dwFileLen = 0;
+  if (m_pFileRead) {
+    m_dwFileLen = (uint32_t)m_pFileRead->GetSize();
+  }
+  m_dwCurrentOffset = 0;
+  m_dwXRefOffset = 0;
+  m_bufferOffset = 0;
+  m_dwFirstPageNo = 0;
+  m_bufferSize = 0;
+  m_PagesObjNum = 0;
+  m_dwCurrentXRefSteam = 0;
+  m_dwAcroFormObjNum = 0;
+  m_dwInfoObjNum = 0;
+  m_pDocument = 0;
+  m_dwEncryptObjNum = 0;
+  m_dwPrevXRefOffset = 0;
+  m_dwLastXRefOffset = 0;
+  m_bDocAvail = FALSE;
+  m_bMainXRefLoadTried = FALSE;
+  m_bDocAvail = FALSE;
+  m_bLinearized = FALSE;
+  m_bPagesLoad = FALSE;
+  m_bPagesTreeLoad = FALSE;
+  m_bMainXRefLoadedOK = FALSE;
+  m_bAnnotsLoad = FALSE;
+  m_bHaveAcroForm = FALSE;
+  m_bAcroFormLoad = FALSE;
+  m_bPageLoadedOK = FALSE;
+  m_bNeedDownLoadResource = FALSE;
+  m_bLinearizedFormParamLoad = FALSE;
+  m_pLinearized = nullptr;
+  m_pRoot = nullptr;
+  m_pTrailer = nullptr;
+  m_pCurrentParser = nullptr;
+  m_pAcroForm = nullptr;
+  m_pPageDict = nullptr;
+  m_pPageResource = nullptr;
+  m_docStatus = PDF_DATAAVAIL_HEADER;
+  m_parser.m_bOwnFileRead = false;
+  m_bTotalLoadPageTree = FALSE;
+  m_bCurPageDictLoadOK = FALSE;
+  m_bLinearedDataOK = FALSE;
+  m_bSupportHintTable = bSupportHintTable;
+}
+CPDF_DataAvail::~CPDF_DataAvail() {
+  m_pHintTables.reset();
+  if (m_pLinearized)
+    m_pLinearized->Release();
+
+  if (m_pRoot)
+    m_pRoot->Release();
+
+  if (m_pTrailer)
+    m_pTrailer->Release();
+
+  int iSize = m_arrayAcroforms.GetSize();
+  for (int i = 0; i < iSize; ++i)
+    m_arrayAcroforms.GetAt(i)->Release();
+}
+
+void CPDF_DataAvail::SetDocument(CPDF_Document* pDoc) {
+  m_pDocument = pDoc;
+}
+
+uint32_t CPDF_DataAvail::GetObjectSize(uint32_t objnum, FX_FILESIZE& offset) {
+  CPDF_Parser* pParser = m_pDocument->GetParser();
+  if (!pParser || !pParser->IsValidObjectNumber(objnum))
+    return 0;
+
+  if (pParser->GetObjectType(objnum) == 2)
+    objnum = pParser->GetObjectPositionOrZero(objnum);
+
+  if (pParser->GetObjectType(objnum) != 1 &&
+      pParser->GetObjectType(objnum) != 255) {
+    return 0;
+  }
+
+  offset = pParser->GetObjectPositionOrZero(objnum);
+  if (offset == 0)
+    return 0;
+
+  auto it = pParser->m_SortedOffset.find(offset);
+  if (it == pParser->m_SortedOffset.end() ||
+      ++it == pParser->m_SortedOffset.end()) {
+    return 0;
+  }
+  return *it - offset;
+}
+
+FX_BOOL CPDF_DataAvail::IsObjectsAvail(
+    CFX_ArrayTemplate<CPDF_Object*>& obj_array,
+    FX_BOOL bParsePage,
+    DownloadHints* pHints,
+    CFX_ArrayTemplate<CPDF_Object*>& ret_array) {
+  if (!obj_array.GetSize())
+    return TRUE;
+
+  uint32_t count = 0;
+  CFX_ArrayTemplate<CPDF_Object*> new_obj_array;
+  for (int i = 0; i < obj_array.GetSize(); i++) {
+    CPDF_Object* pObj = obj_array[i];
+    if (!pObj)
+      continue;
+
+    int32_t type = pObj->GetType();
+    switch (type) {
+      case CPDF_Object::ARRAY: {
+        CPDF_Array* pArray = pObj->AsArray();
+        for (size_t k = 0; k < pArray->GetCount(); ++k)
+          new_obj_array.Add(pArray->GetObjectAt(k));
+      } break;
+      case CPDF_Object::STREAM:
+        pObj = pObj->GetDict();
+      case CPDF_Object::DICTIONARY: {
+        CPDF_Dictionary* pDict = pObj->GetDict();
+        if (pDict && pDict->GetStringFor("Type") == "Page" && !bParsePage)
+          continue;
+
+        for (const auto& it : *pDict) {
+          const CFX_ByteString& key = it.first;
+          CPDF_Object* value = it.second;
+          if (key != "Parent")
+            new_obj_array.Add(value);
+        }
+      } break;
+      case CPDF_Object::REFERENCE: {
+        CPDF_Reference* pRef = pObj->AsReference();
+        uint32_t dwNum = pRef->GetRefObjNum();
+
+        FX_FILESIZE offset;
+        uint32_t size = GetObjectSize(dwNum, offset);
+        if (size == 0 || offset < 0 || offset >= m_dwFileLen)
+          break;
+
+        if (!IsDataAvail(offset, size, pHints)) {
+          ret_array.Add(pObj);
+          count++;
+        } else if (!pdfium::ContainsKey(m_ObjectSet, dwNum)) {
+          m_ObjectSet.insert(dwNum);
+          CPDF_Object* pReferred =
+              m_pDocument->GetOrParseIndirectObject(pRef->GetRefObjNum());
+          if (pReferred)
+            new_obj_array.Add(pReferred);
+        }
+      } break;
+    }
+  }
+
+  if (count > 0) {
+    for (int i = 0; i < new_obj_array.GetSize(); ++i) {
+      CPDF_Object* pObj = new_obj_array[i];
+      if (CPDF_Reference* pRef = pObj->AsReference()) {
+        uint32_t dwNum = pRef->GetRefObjNum();
+        if (!pdfium::ContainsKey(m_ObjectSet, dwNum))
+          ret_array.Add(pObj);
+      } else {
+        ret_array.Add(pObj);
+      }
+    }
+    return FALSE;
+  }
+
+  obj_array.RemoveAll();
+  obj_array.Append(new_obj_array);
+  return IsObjectsAvail(obj_array, FALSE, pHints, ret_array);
+}
+
+CPDF_DataAvail::DocAvailStatus CPDF_DataAvail::IsDocAvail(
+    DownloadHints* pHints) {
+  if (!m_dwFileLen && m_pFileRead) {
+    m_dwFileLen = (uint32_t)m_pFileRead->GetSize();
+    if (!m_dwFileLen)
+      return DataError;
+  }
+
+  while (!m_bDocAvail) {
+    if (!CheckDocStatus(pHints))
+      return DataNotAvailable;
+  }
+
+  return DataAvailable;
+}
+
+FX_BOOL CPDF_DataAvail::CheckAcroFormSubObject(DownloadHints* pHints) {
+  if (!m_objs_array.GetSize()) {
+    m_objs_array.RemoveAll();
+    m_ObjectSet.clear();
+    CFX_ArrayTemplate<CPDF_Object*> obj_array;
+    obj_array.Append(m_arrayAcroforms);
+    FX_BOOL bRet = IsObjectsAvail(obj_array, FALSE, pHints, m_objs_array);
+    if (bRet)
+      m_objs_array.RemoveAll();
+    return bRet;
+  }
+
+  CFX_ArrayTemplate<CPDF_Object*> new_objs_array;
+  FX_BOOL bRet = IsObjectsAvail(m_objs_array, FALSE, pHints, new_objs_array);
+  if (bRet) {
+    int32_t iSize = m_arrayAcroforms.GetSize();
+    for (int32_t i = 0; i < iSize; ++i) {
+      m_arrayAcroforms.GetAt(i)->Release();
+    }
+    m_arrayAcroforms.RemoveAll();
+  } else {
+    m_objs_array.RemoveAll();
+    m_objs_array.Append(new_objs_array);
+  }
+  return bRet;
+}
+
+FX_BOOL CPDF_DataAvail::CheckAcroForm(DownloadHints* pHints) {
+  FX_BOOL bExist = FALSE;
+  m_pAcroForm = GetObject(m_dwAcroFormObjNum, pHints, &bExist);
+  if (!bExist) {
+    m_docStatus = PDF_DATAAVAIL_PAGETREE;
+    return TRUE;
+  }
+
+  if (!m_pAcroForm) {
+    if (m_docStatus == PDF_DATAAVAIL_ERROR) {
+      m_docStatus = PDF_DATAAVAIL_LOADALLFILE;
+      return TRUE;
+    }
+    return FALSE;
+  }
+
+  m_arrayAcroforms.Add(m_pAcroForm);
+  m_docStatus = PDF_DATAAVAIL_PAGETREE;
+  return TRUE;
+}
+
+FX_BOOL CPDF_DataAvail::CheckDocStatus(DownloadHints* pHints) {
+  switch (m_docStatus) {
+    case PDF_DATAAVAIL_HEADER:
+      return CheckHeader(pHints);
+    case PDF_DATAAVAIL_FIRSTPAGE:
+    case PDF_DATAAVAIL_FIRSTPAGE_PREPARE:
+      return CheckFirstPage(pHints);
+    case PDF_DATAAVAIL_HINTTABLE:
+      return CheckHintTables(pHints);
+    case PDF_DATAAVAIL_END:
+      return CheckEnd(pHints);
+    case PDF_DATAAVAIL_CROSSREF:
+      return CheckCrossRef(pHints);
+    case PDF_DATAAVAIL_CROSSREF_ITEM:
+      return CheckCrossRefItem(pHints);
+    case PDF_DATAAVAIL_CROSSREF_STREAM:
+      return CheckAllCrossRefStream(pHints);
+    case PDF_DATAAVAIL_TRAILER:
+      return CheckTrailer(pHints);
+    case PDF_DATAAVAIL_TRAILER_APPEND:
+      return CheckTrailerAppend(pHints);
+    case PDF_DATAAVAIL_LOADALLCROSSREF:
+      return LoadAllXref(pHints);
+    case PDF_DATAAVAIL_LOADALLFILE:
+      return LoadAllFile(pHints);
+    case PDF_DATAAVAIL_ROOT:
+      return CheckRoot(pHints);
+    case PDF_DATAAVAIL_INFO:
+      return CheckInfo(pHints);
+    case PDF_DATAAVAIL_ACROFORM:
+      return CheckAcroForm(pHints);
+    case PDF_DATAAVAIL_PAGETREE:
+      if (m_bTotalLoadPageTree)
+        return CheckPages(pHints);
+      return LoadDocPages(pHints);
+    case PDF_DATAAVAIL_PAGE:
+      if (m_bTotalLoadPageTree)
+        return CheckPage(pHints);
+      m_docStatus = PDF_DATAAVAIL_PAGE_LATERLOAD;
+      return TRUE;
+    case PDF_DATAAVAIL_ERROR:
+      return LoadAllFile(pHints);
+    case PDF_DATAAVAIL_PAGE_LATERLOAD:
+      m_docStatus = PDF_DATAAVAIL_PAGE;
+    default:
+      m_bDocAvail = TRUE;
+      return TRUE;
+  }
+}
+
+FX_BOOL CPDF_DataAvail::CheckPageStatus(DownloadHints* pHints) {
+  switch (m_docStatus) {
+    case PDF_DATAAVAIL_PAGETREE:
+      return CheckPages(pHints);
+    case PDF_DATAAVAIL_PAGE:
+      return CheckPage(pHints);
+    case PDF_DATAAVAIL_ERROR:
+      return LoadAllFile(pHints);
+    default:
+      m_bPagesTreeLoad = TRUE;
+      m_bPagesLoad = TRUE;
+      return TRUE;
+  }
+}
+
+FX_BOOL CPDF_DataAvail::LoadAllFile(DownloadHints* pHints) {
+  if (m_pFileAvail->IsDataAvail(0, (uint32_t)m_dwFileLen)) {
+    m_docStatus = PDF_DATAAVAIL_DONE;
+    return TRUE;
+  }
+
+  pHints->AddSegment(0, (uint32_t)m_dwFileLen);
+  return FALSE;
+}
+
+FX_BOOL CPDF_DataAvail::LoadAllXref(DownloadHints* pHints) {
+  m_parser.m_pSyntax->InitParser(m_pFileRead, (uint32_t)m_dwHeaderOffset);
+  m_parser.m_bOwnFileRead = false;
+  if (!m_parser.LoadAllCrossRefV4(m_dwLastXRefOffset) &&
+      !m_parser.LoadAllCrossRefV5(m_dwLastXRefOffset)) {
+    m_docStatus = PDF_DATAAVAIL_LOADALLFILE;
+    return FALSE;
+  }
+
+  m_dwRootObjNum = m_parser.GetRootObjNum();
+  m_dwInfoObjNum = m_parser.GetInfoObjNum();
+  m_pCurrentParser = &m_parser;
+  m_docStatus = PDF_DATAAVAIL_ROOT;
+  return TRUE;
+}
+
+CPDF_Object* CPDF_DataAvail::GetObject(uint32_t objnum,
+                                       DownloadHints* pHints,
+                                       FX_BOOL* pExistInFile) {
+  CPDF_Object* pRet = nullptr;
+  uint32_t size = 0;
+  FX_FILESIZE offset = 0;
+  CPDF_Parser* pParser = nullptr;
+
+  if (pExistInFile)
+    *pExistInFile = TRUE;
+
+  if (m_pDocument) {
+    size = GetObjectSize(objnum, offset);
+    pParser = m_pDocument->GetParser();
+  } else {
+    size = (uint32_t)m_parser.GetObjectSize(objnum);
+    offset = m_parser.GetObjectOffset(objnum);
+    pParser = &m_parser;
+  }
+
+  if (!IsDataAvail(offset, size, pHints))
+    return nullptr;
+
+  if (pParser)
+    pRet = pParser->ParseIndirectObject(nullptr, objnum);
+
+  if (!pRet && pExistInFile)
+    *pExistInFile = FALSE;
+
+  return pRet;
+}
+
+FX_BOOL CPDF_DataAvail::CheckInfo(DownloadHints* pHints) {
+  FX_BOOL bExist = FALSE;
+  CPDF_Object* pInfo = GetObject(m_dwInfoObjNum, pHints, &bExist);
+  if (!bExist) {
+    m_docStatus =
+        (m_bHaveAcroForm ? PDF_DATAAVAIL_ACROFORM : PDF_DATAAVAIL_PAGETREE);
+    return TRUE;
+  }
+
+  if (!pInfo) {
+    if (m_docStatus == PDF_DATAAVAIL_ERROR) {
+      m_docStatus = PDF_DATAAVAIL_LOADALLFILE;
+      return TRUE;
+    }
+
+    if (m_Pos == m_dwFileLen)
+      m_docStatus = PDF_DATAAVAIL_ERROR;
+    return FALSE;
+  }
+
+  if (pInfo)
+    pInfo->Release();
+
+  m_docStatus =
+      (m_bHaveAcroForm ? PDF_DATAAVAIL_ACROFORM : PDF_DATAAVAIL_PAGETREE);
+
+  return TRUE;
+}
+
+FX_BOOL CPDF_DataAvail::CheckRoot(DownloadHints* pHints) {
+  FX_BOOL bExist = FALSE;
+  m_pRoot = GetObject(m_dwRootObjNum, pHints, &bExist);
+  if (!bExist) {
+    m_docStatus = PDF_DATAAVAIL_LOADALLFILE;
+    return TRUE;
+  }
+
+  if (!m_pRoot) {
+    if (m_docStatus == PDF_DATAAVAIL_ERROR) {
+      m_docStatus = PDF_DATAAVAIL_LOADALLFILE;
+      return TRUE;
+    }
+    return FALSE;
+  }
+
+  CPDF_Dictionary* pDict = m_pRoot->GetDict();
+  if (!pDict) {
+    m_docStatus = PDF_DATAAVAIL_ERROR;
+    return FALSE;
+  }
+
+  CPDF_Reference* pRef = ToReference(pDict->GetObjectFor("Pages"));
+  if (!pRef) {
+    m_docStatus = PDF_DATAAVAIL_ERROR;
+    return FALSE;
+  }
+
+  m_PagesObjNum = pRef->GetRefObjNum();
+  CPDF_Reference* pAcroFormRef =
+      ToReference(m_pRoot->GetDict()->GetObjectFor("AcroForm"));
+  if (pAcroFormRef) {
+    m_bHaveAcroForm = TRUE;
+    m_dwAcroFormObjNum = pAcroFormRef->GetRefObjNum();
+  }
+
+  if (m_dwInfoObjNum) {
+    m_docStatus = PDF_DATAAVAIL_INFO;
+  } else {
+    m_docStatus =
+        m_bHaveAcroForm ? PDF_DATAAVAIL_ACROFORM : PDF_DATAAVAIL_PAGETREE;
+  }
+  return TRUE;
+}
+
+FX_BOOL CPDF_DataAvail::PreparePageItem() {
+  CPDF_Dictionary* pRoot = m_pDocument->GetRoot();
+  CPDF_Reference* pRef =
+      ToReference(pRoot ? pRoot->GetObjectFor("Pages") : nullptr);
+  if (!pRef) {
+    m_docStatus = PDF_DATAAVAIL_ERROR;
+    return FALSE;
+  }
+
+  m_PagesObjNum = pRef->GetRefObjNum();
+  m_pCurrentParser = m_pDocument->GetParser();
+  m_docStatus = PDF_DATAAVAIL_PAGETREE;
+  return TRUE;
+}
+
+bool CPDF_DataAvail::IsFirstCheck(uint32_t dwPage) {
+  return m_pageMapCheckState.insert(dwPage).second;
+}
+
+void CPDF_DataAvail::ResetFirstCheck(uint32_t dwPage) {
+  m_pageMapCheckState.erase(dwPage);
+}
+
+FX_BOOL CPDF_DataAvail::CheckPage(DownloadHints* pHints) {
+  uint32_t iPageObjs = m_PageObjList.GetSize();
+  CFX_ArrayTemplate<uint32_t> UnavailObjList;
+  for (uint32_t i = 0; i < iPageObjs; ++i) {
+    uint32_t dwPageObjNum = m_PageObjList.GetAt(i);
+    FX_BOOL bExist = FALSE;
+    CPDF_Object* pObj = GetObject(dwPageObjNum, pHints, &bExist);
+    if (!pObj) {
+      if (bExist)
+        UnavailObjList.Add(dwPageObjNum);
+      continue;
+    }
+
+    CPDF_Array* pArray = ToArray(pObj);
+    if (pArray) {
+      for (CPDF_Object* pArrayObj : *pArray) {
+        if (CPDF_Reference* pRef = ToReference(pArrayObj))
+          UnavailObjList.Add(pRef->GetRefObjNum());
+      }
+    }
+
+    if (!pObj->IsDictionary()) {
+      pObj->Release();
+      continue;
+    }
+
+    CFX_ByteString type = pObj->GetDict()->GetStringFor("Type");
+    if (type == "Pages") {
+      m_PagesArray.Add(pObj);
+      continue;
+    }
+    pObj->Release();
+  }
+
+  m_PageObjList.RemoveAll();
+  if (UnavailObjList.GetSize()) {
+    m_PageObjList.Append(UnavailObjList);
+    return FALSE;
+  }
+
+  uint32_t iPages = m_PagesArray.GetSize();
+  for (uint32_t i = 0; i < iPages; i++) {
+    CPDF_Object* pPages = m_PagesArray.GetAt(i);
+    if (!pPages)
+      continue;
+
+    if (!GetPageKids(m_pCurrentParser, pPages)) {
+      pPages->Release();
+      while (++i < iPages) {
+        pPages = m_PagesArray.GetAt(i);
+        pPages->Release();
+      }
+      m_PagesArray.RemoveAll();
+
+      m_docStatus = PDF_DATAAVAIL_ERROR;
+      return FALSE;
+    }
+    pPages->Release();
+  }
+
+  m_PagesArray.RemoveAll();
+  if (!m_PageObjList.GetSize())
+    m_docStatus = PDF_DATAAVAIL_DONE;
+  return TRUE;
+}
+
+FX_BOOL CPDF_DataAvail::GetPageKids(CPDF_Parser* pParser, CPDF_Object* pPages) {
+  if (!pParser) {
+    m_docStatus = PDF_DATAAVAIL_ERROR;
+    return FALSE;
+  }
+
+  CPDF_Dictionary* pDict = pPages->GetDict();
+  CPDF_Object* pKids = pDict ? pDict->GetObjectFor("Kids") : nullptr;
+  if (!pKids)
+    return TRUE;
+
+  switch (pKids->GetType()) {
+    case CPDF_Object::REFERENCE:
+      m_PageObjList.Add(pKids->AsReference()->GetRefObjNum());
+      break;
+    case CPDF_Object::ARRAY: {
+      CPDF_Array* pKidsArray = pKids->AsArray();
+      for (size_t i = 0; i < pKidsArray->GetCount(); ++i) {
+        if (CPDF_Reference* pRef = ToReference(pKidsArray->GetObjectAt(i)))
+          m_PageObjList.Add(pRef->GetRefObjNum());
+      }
+    } break;
+    default:
+      m_docStatus = PDF_DATAAVAIL_ERROR;
+      return FALSE;
+  }
+  return TRUE;
+}
+
+FX_BOOL CPDF_DataAvail::CheckPages(DownloadHints* pHints) {
+  FX_BOOL bExist = FALSE;
+  CPDF_Object* pPages = GetObject(m_PagesObjNum, pHints, &bExist);
+  if (!bExist) {
+    m_docStatus = PDF_DATAAVAIL_LOADALLFILE;
+    return TRUE;
+  }
+
+  if (!pPages) {
+    if (m_docStatus == PDF_DATAAVAIL_ERROR) {
+      m_docStatus = PDF_DATAAVAIL_LOADALLFILE;
+      return TRUE;
+    }
+    return FALSE;
+  }
+
+  if (!GetPageKids(m_pCurrentParser, pPages)) {
+    pPages->Release();
+    m_docStatus = PDF_DATAAVAIL_ERROR;
+    return FALSE;
+  }
+
+  pPages->Release();
+  m_docStatus = PDF_DATAAVAIL_PAGE;
+  return TRUE;
+}
+
+FX_BOOL CPDF_DataAvail::CheckHeader(DownloadHints* pHints) {
+  ASSERT(m_dwFileLen >= 0);
+  const uint32_t kReqSize = std::min(static_cast<uint32_t>(m_dwFileLen), 1024U);
+
+  if (m_pFileAvail->IsDataAvail(0, kReqSize)) {
+    uint8_t buffer[1024];
+    m_pFileRead->ReadBlock(buffer, 0, kReqSize);
+
+    if (IsLinearizedFile(buffer, kReqSize)) {
+      m_docStatus = PDF_DATAAVAIL_FIRSTPAGE;
+    } else {
+      if (m_docStatus == PDF_DATAAVAIL_ERROR)
+        return FALSE;
+      m_docStatus = PDF_DATAAVAIL_END;
+    }
+    return TRUE;
+  }
+
+  pHints->AddSegment(0, kReqSize);
+  return FALSE;
+}
+
+FX_BOOL CPDF_DataAvail::CheckFirstPage(DownloadHints* pHints) {
+  CPDF_Dictionary* pDict = m_pLinearized->GetDict();
+  CPDF_Object* pEndOffSet = pDict ? pDict->GetObjectFor("E") : nullptr;
+  if (!pEndOffSet) {
+    m_docStatus = PDF_DATAAVAIL_ERROR;
+    return FALSE;
+  }
+
+  CPDF_Object* pXRefOffset = pDict ? pDict->GetObjectFor("T") : nullptr;
+  if (!pXRefOffset) {
+    m_docStatus = PDF_DATAAVAIL_ERROR;
+    return FALSE;
+  }
+
+  CPDF_Object* pFileLen = pDict ? pDict->GetObjectFor("L") : nullptr;
+  if (!pFileLen) {
+    m_docStatus = PDF_DATAAVAIL_ERROR;
+    return FALSE;
+  }
+
+  FX_BOOL bNeedDownLoad = FALSE;
+  if (pEndOffSet->IsNumber()) {
+    uint32_t dwEnd = pEndOffSet->GetInteger();
+    dwEnd += 512;
+    if ((FX_FILESIZE)dwEnd > m_dwFileLen)
+      dwEnd = (uint32_t)m_dwFileLen;
+
+    int32_t iStartPos = (int32_t)(m_dwFileLen > 1024 ? 1024 : m_dwFileLen);
+    int32_t iSize = dwEnd > 1024 ? dwEnd - 1024 : 0;
+    if (!m_pFileAvail->IsDataAvail(iStartPos, iSize)) {
+      pHints->AddSegment(iStartPos, iSize);
+      bNeedDownLoad = TRUE;
+    }
+  }
+
+  m_dwLastXRefOffset = 0;
+  FX_FILESIZE dwFileLen = 0;
+  if (pXRefOffset->IsNumber())
+    m_dwLastXRefOffset = pXRefOffset->GetInteger();
+
+  if (pFileLen->IsNumber())
+    dwFileLen = pFileLen->GetInteger();
+
+  if (!m_pFileAvail->IsDataAvail(m_dwLastXRefOffset,
+                                 (uint32_t)(dwFileLen - m_dwLastXRefOffset))) {
+    if (m_docStatus == PDF_DATAAVAIL_FIRSTPAGE) {
+      uint32_t dwSize = (uint32_t)(dwFileLen - m_dwLastXRefOffset);
+      FX_FILESIZE offset = m_dwLastXRefOffset;
+      if (dwSize < 512 && dwFileLen > 512) {
+        dwSize = 512;
+        offset = dwFileLen - 512;
+      }
+      pHints->AddSegment(offset, dwSize);
+    }
+  } else {
+    m_docStatus = PDF_DATAAVAIL_FIRSTPAGE_PREPARE;
+  }
+
+  if (bNeedDownLoad || m_docStatus != PDF_DATAAVAIL_FIRSTPAGE_PREPARE) {
+    m_docStatus = PDF_DATAAVAIL_FIRSTPAGE_PREPARE;
+    return FALSE;
+  }
+
+  m_docStatus =
+      m_bSupportHintTable ? PDF_DATAAVAIL_HINTTABLE : PDF_DATAAVAIL_DONE;
+  return TRUE;
+}
+
+FX_BOOL CPDF_DataAvail::IsDataAvail(FX_FILESIZE offset,
+                                    uint32_t size,
+                                    DownloadHints* pHints) {
+  if (offset < 0 || offset > m_dwFileLen)
+    return TRUE;
+
+  FX_SAFE_FILESIZE safeSize = offset;
+  safeSize += size;
+  safeSize += 512;
+  if (!safeSize.IsValid() || safeSize.ValueOrDie() > m_dwFileLen)
+    size = m_dwFileLen - offset;
+  else
+    size += 512;
+
+  if (!m_pFileAvail->IsDataAvail(offset, size)) {
+    pHints->AddSegment(offset, size);
+    return FALSE;
+  }
+  return TRUE;
+}
+
+FX_BOOL CPDF_DataAvail::CheckHintTables(DownloadHints* pHints) {
+  CPDF_Dictionary* pDict = m_pLinearized->GetDict();
+  if (!pDict) {
+    m_docStatus = PDF_DATAAVAIL_ERROR;
+    return FALSE;
+  }
+
+  // The actual value is not required here, but validate its existence and type.
+  CPDF_Number* pFirstPage = ToNumber(pDict->GetDirectObjectFor("O"));
+  if (!pFirstPage || !pFirstPage->IsInteger()) {
+    m_docStatus = PDF_DATAAVAIL_ERROR;
+    return FALSE;
+  }
+
+  CPDF_Number* pPageCount = ToNumber(pDict->GetDirectObjectFor("N"));
+  if (!pPageCount || !pPageCount->IsInteger()) {
+    m_docStatus = PDF_DATAAVAIL_ERROR;
+    return FALSE;
+  }
+
+  int nPageCount = pPageCount->GetInteger();
+  if (nPageCount <= 1) {
+    m_docStatus = PDF_DATAAVAIL_DONE;
+    return TRUE;
+  }
+
+  CPDF_Array* pHintStreamRange = pDict->GetArrayFor("H");
+  size_t nHintStreamSize = pHintStreamRange ? pHintStreamRange->GetCount() : 0;
+  if (nHintStreamSize != 2 && nHintStreamSize != 4) {
+    m_docStatus = PDF_DATAAVAIL_ERROR;
+    return FALSE;
+  }
+
+  for (const CPDF_Object* pArrayObject : *pHintStreamRange) {
+    const CPDF_Number* pNumber = ToNumber(pArrayObject->GetDirect());
+    if (!pNumber || !pNumber->IsInteger()) {
+      m_docStatus = PDF_DATAAVAIL_ERROR;
+      return FALSE;
+    }
+  }
+
+  FX_FILESIZE szHintStart = pHintStreamRange->GetIntegerAt(0);
+  FX_FILESIZE szHintLength = pHintStreamRange->GetIntegerAt(1);
+  if (szHintStart < 0 || szHintLength <= 0) {
+    m_docStatus = PDF_DATAAVAIL_ERROR;
+    return FALSE;
+  }
+
+  if (!IsDataAvail(szHintStart, szHintLength, pHints))
+    return FALSE;
+
+  m_syntaxParser.InitParser(m_pFileRead, m_dwHeaderOffset);
+
+  std::unique_ptr<CPDF_HintTables> pHintTables(
+      new CPDF_HintTables(this, pDict));
+  std::unique_ptr<CPDF_Object, ReleaseDeleter<CPDF_Object>> pHintStream(
+      ParseIndirectObjectAt(szHintStart, 0));
+  CPDF_Stream* pStream = ToStream(pHintStream.get());
+  if (pStream && pHintTables->LoadHintStream(pStream))
+    m_pHintTables = std::move(pHintTables);
+
+  m_docStatus = PDF_DATAAVAIL_DONE;
+  return TRUE;
+}
+
+CPDF_Object* CPDF_DataAvail::ParseIndirectObjectAt(
+    FX_FILESIZE pos,
+    uint32_t objnum,
+    CPDF_IndirectObjectHolder* pObjList) {
+  FX_FILESIZE SavedPos = m_syntaxParser.SavePos();
+  m_syntaxParser.RestorePos(pos);
+
+  bool bIsNumber;
+  CFX_ByteString word = m_syntaxParser.GetNextWord(&bIsNumber);
+  if (!bIsNumber)
+    return nullptr;
+
+  uint32_t parser_objnum = FXSYS_atoui(word.c_str());
+  if (objnum && parser_objnum != objnum)
+    return nullptr;
+
+  word = m_syntaxParser.GetNextWord(&bIsNumber);
+  if (!bIsNumber)
+    return nullptr;
+
+  uint32_t gennum = FXSYS_atoui(word.c_str());
+  if (m_syntaxParser.GetKeyword() != "obj") {
+    m_syntaxParser.RestorePos(SavedPos);
+    return nullptr;
+  }
+
+  CPDF_Object* pObj =
+      m_syntaxParser.GetObject(pObjList, parser_objnum, gennum, true);
+  m_syntaxParser.RestorePos(SavedPos);
+  return pObj;
+}
+
+CPDF_DataAvail::DocLinearizationStatus CPDF_DataAvail::IsLinearizedPDF() {
+  const uint32_t kReqSize = 1024;
+  if (!m_pFileAvail->IsDataAvail(0, kReqSize))
+    return LinearizationUnknown;
+
+  if (!m_pFileRead)
+    return NotLinearized;
+
+  FX_FILESIZE dwSize = m_pFileRead->GetSize();
+  if (dwSize < (FX_FILESIZE)kReqSize)
+    return LinearizationUnknown;
+
+  uint8_t buffer[1024];
+  m_pFileRead->ReadBlock(buffer, 0, kReqSize);
+  if (IsLinearizedFile(buffer, kReqSize))
+    return Linearized;
+
+  return NotLinearized;
+}
+
+FX_BOOL CPDF_DataAvail::IsLinearized() {
+  return m_bLinearized;
+}
+
+FX_BOOL CPDF_DataAvail::IsLinearizedFile(uint8_t* pData, uint32_t dwLen) {
+  if (m_pLinearized)
+    return m_bLinearized;
+
+  ScopedFileStream file(FX_CreateMemoryStream(pData, (size_t)dwLen, FALSE));
+
+  int32_t offset = GetHeaderOffset(file.get());
+  if (offset == -1) {
+    m_docStatus = PDF_DATAAVAIL_ERROR;
+    return FALSE;
+  }
+
+  m_dwHeaderOffset = offset;
+  m_syntaxParser.InitParser(file.get(), offset);
+  m_syntaxParser.RestorePos(m_syntaxParser.m_HeaderOffset + 9);
+
+  bool bNumber;
+  CFX_ByteString wordObjNum = m_syntaxParser.GetNextWord(&bNumber);
+  if (!bNumber)
+    return FALSE;
+
+  uint32_t objnum = FXSYS_atoui(wordObjNum.c_str());
+  m_pLinearized =
+      ParseIndirectObjectAt(m_syntaxParser.m_HeaderOffset + 9, objnum);
+  if (!m_pLinearized)
+    return FALSE;
+
+  CPDF_Dictionary* pDict = m_pLinearized->GetDict();
+  if (!pDict || !pDict->GetObjectFor("Linearized"))
+    return FALSE;
+
+  CPDF_Object* pLen = pDict->GetObjectFor("L");
+  if (!pLen)
+    return FALSE;
+
+  if ((FX_FILESIZE)pLen->GetInteger() != m_pFileRead->GetSize())
+    return FALSE;
+
+  m_bLinearized = TRUE;
+
+  if (CPDF_Number* pNo = ToNumber(pDict->GetObjectFor("P")))
+    m_dwFirstPageNo = pNo->GetInteger();
+
+  return TRUE;
+}
+
+FX_BOOL CPDF_DataAvail::CheckEnd(DownloadHints* pHints) {
+  uint32_t req_pos = (uint32_t)(m_dwFileLen > 1024 ? m_dwFileLen - 1024 : 0);
+  uint32_t dwSize = (uint32_t)(m_dwFileLen - req_pos);
+
+  if (m_pFileAvail->IsDataAvail(req_pos, dwSize)) {
+    uint8_t buffer[1024];
+    m_pFileRead->ReadBlock(buffer, req_pos, dwSize);
+
+    ScopedFileStream file(FX_CreateMemoryStream(buffer, (size_t)dwSize, FALSE));
+    m_syntaxParser.InitParser(file.get(), 0);
+    m_syntaxParser.RestorePos(dwSize - 1);
+
+    if (m_syntaxParser.SearchWord("startxref", TRUE, FALSE, dwSize)) {
+      m_syntaxParser.GetNextWord(nullptr);
+
+      bool bNumber;
+      CFX_ByteString xrefpos_str = m_syntaxParser.GetNextWord(&bNumber);
+      if (!bNumber) {
+        m_docStatus = PDF_DATAAVAIL_ERROR;
+        return FALSE;
+      }
+
+      m_dwXRefOffset = (FX_FILESIZE)FXSYS_atoi64(xrefpos_str.c_str());
+      if (!m_dwXRefOffset || m_dwXRefOffset > m_dwFileLen) {
+        m_docStatus = PDF_DATAAVAIL_LOADALLFILE;
+        return TRUE;
+      }
+
+      m_dwLastXRefOffset = m_dwXRefOffset;
+      SetStartOffset(m_dwXRefOffset);
+      m_docStatus = PDF_DATAAVAIL_CROSSREF;
+      return TRUE;
+    }
+
+    m_docStatus = PDF_DATAAVAIL_LOADALLFILE;
+    return TRUE;
+  }
+
+  pHints->AddSegment(req_pos, dwSize);
+  return FALSE;
+}
+
+int32_t CPDF_DataAvail::CheckCrossRefStream(DownloadHints* pHints,
+                                            FX_FILESIZE& xref_offset) {
+  xref_offset = 0;
+  uint32_t req_size =
+      (uint32_t)(m_Pos + 512 > m_dwFileLen ? m_dwFileLen - m_Pos : 512);
+
+  if (m_pFileAvail->IsDataAvail(m_Pos, req_size)) {
+    int32_t iSize = (int32_t)(m_Pos + req_size - m_dwCurrentXRefSteam);
+    CFX_BinaryBuf buf(iSize);
+    uint8_t* pBuf = buf.GetBuffer();
+
+    m_pFileRead->ReadBlock(pBuf, m_dwCurrentXRefSteam, iSize);
+
+    ScopedFileStream file(FX_CreateMemoryStream(pBuf, (size_t)iSize, FALSE));
+    m_parser.m_pSyntax->InitParser(file.get(), 0);
+
+    bool bNumber;
+    CFX_ByteString objnum = m_parser.m_pSyntax->GetNextWord(&bNumber);
+    if (!bNumber)
+      return -1;
+
+    uint32_t objNum = FXSYS_atoui(objnum.c_str());
+    CPDF_Object* pObj = m_parser.ParseIndirectObjectAt(nullptr, 0, objNum);
+    if (!pObj) {
+      m_Pos += m_parser.m_pSyntax->SavePos();
+      return 0;
+    }
+
+    CPDF_Dictionary* pDict = pObj->GetDict();
+    CPDF_Name* pName = ToName(pDict ? pDict->GetObjectFor("Type") : nullptr);
+    if (pName) {
+      if (pName->GetString() == "XRef") {
+        m_Pos += m_parser.m_pSyntax->SavePos();
+        xref_offset = pObj->GetDict()->GetIntegerFor("Prev");
+        pObj->Release();
+        return 1;
+      }
+    }
+    pObj->Release();
+    return -1;
+  }
+  pHints->AddSegment(m_Pos, req_size);
+  return 0;
+}
+
+void CPDF_DataAvail::SetStartOffset(FX_FILESIZE dwOffset) {
+  m_Pos = dwOffset;
+}
+
+FX_BOOL CPDF_DataAvail::GetNextToken(CFX_ByteString& token) {
+  uint8_t ch;
+  if (!GetNextChar(ch))
+    return FALSE;
+
+  while (1) {
+    while (PDFCharIsWhitespace(ch)) {
+      if (!GetNextChar(ch))
+        return FALSE;
+    }
+
+    if (ch != '%')
+      break;
+
+    while (1) {
+      if (!GetNextChar(ch))
+        return FALSE;
+      if (PDFCharIsLineEnding(ch))
+        break;
+    }
+  }
+
+  uint8_t buffer[256];
+  uint32_t index = 0;
+  if (PDFCharIsDelimiter(ch)) {
+    buffer[index++] = ch;
+    if (ch == '/') {
+      while (1) {
+        if (!GetNextChar(ch))
+          return FALSE;
+
+        if (!PDFCharIsOther(ch) && !PDFCharIsNumeric(ch)) {
+          m_Pos--;
+          CFX_ByteString ret(buffer, index);
+          token = ret;
+          return TRUE;
+        }
+
+        if (index < sizeof(buffer))
+          buffer[index++] = ch;
+      }
+    } else if (ch == '<') {
+      if (!GetNextChar(ch))
+        return FALSE;
+
+      if (ch == '<')
+        buffer[index++] = ch;
+      else
+        m_Pos--;
+    } else if (ch == '>') {
+      if (!GetNextChar(ch))
+        return FALSE;
+
+      if (ch == '>')
+        buffer[index++] = ch;
+      else
+        m_Pos--;
+    }
+
+    CFX_ByteString ret(buffer, index);
+    token = ret;
+    return TRUE;
+  }
+
+  while (1) {
+    if (index < sizeof(buffer))
+      buffer[index++] = ch;
+
+    if (!GetNextChar(ch))
+      return FALSE;
+
+    if (PDFCharIsDelimiter(ch) || PDFCharIsWhitespace(ch)) {
+      m_Pos--;
+      break;
+    }
+  }
+
+  token = CFX_ByteString(buffer, index);
+  return TRUE;
+}
+
+FX_BOOL CPDF_DataAvail::GetNextChar(uint8_t& ch) {
+  FX_FILESIZE pos = m_Pos;
+  if (pos >= m_dwFileLen)
+    return FALSE;
+
+  if (m_bufferOffset >= pos ||
+      (FX_FILESIZE)(m_bufferOffset + m_bufferSize) <= pos) {
+    FX_FILESIZE read_pos = pos;
+    uint32_t read_size = 512;
+    if ((FX_FILESIZE)read_size > m_dwFileLen)
+      read_size = (uint32_t)m_dwFileLen;
+
+    if ((FX_FILESIZE)(read_pos + read_size) > m_dwFileLen)
+      read_pos = m_dwFileLen - read_size;
+
+    if (!m_pFileRead->ReadBlock(m_bufferData, read_pos, read_size))
+      return FALSE;
+
+    m_bufferOffset = read_pos;
+    m_bufferSize = read_size;
+  }
+  ch = m_bufferData[pos - m_bufferOffset];
+  m_Pos++;
+  return TRUE;
+}
+
+FX_BOOL CPDF_DataAvail::CheckCrossRefItem(DownloadHints* pHints) {
+  int32_t iSize = 0;
+  CFX_ByteString token;
+  while (1) {
+    if (!GetNextToken(token)) {
+      iSize = (int32_t)(m_Pos + 512 > m_dwFileLen ? m_dwFileLen - m_Pos : 512);
+      pHints->AddSegment(m_Pos, iSize);
+      return FALSE;
+    }
+
+    if (token == "trailer") {
+      m_dwTrailerOffset = m_Pos;
+      m_docStatus = PDF_DATAAVAIL_TRAILER;
+      return TRUE;
+    }
+  }
+}
+
+FX_BOOL CPDF_DataAvail::CheckAllCrossRefStream(DownloadHints* pHints) {
+  FX_FILESIZE xref_offset = 0;
+
+  int32_t nRet = CheckCrossRefStream(pHints, xref_offset);
+  if (nRet == 1) {
+    if (!xref_offset) {
+      m_docStatus = PDF_DATAAVAIL_LOADALLCROSSREF;
+    } else {
+      m_dwCurrentXRefSteam = xref_offset;
+      m_Pos = xref_offset;
+    }
+    return TRUE;
+  }
+
+  if (nRet == -1)
+    m_docStatus = PDF_DATAAVAIL_ERROR;
+  return FALSE;
+}
+
+FX_BOOL CPDF_DataAvail::CheckCrossRef(DownloadHints* pHints) {
+  int32_t iSize = 0;
+  CFX_ByteString token;
+  if (!GetNextToken(token)) {
+    iSize = (int32_t)(m_Pos + 512 > m_dwFileLen ? m_dwFileLen - m_Pos : 512);
+    pHints->AddSegment(m_Pos, iSize);
+    return FALSE;
+  }
+
+  if (token == "xref") {
+    while (1) {
+      if (!GetNextToken(token)) {
+        iSize =
+            (int32_t)(m_Pos + 512 > m_dwFileLen ? m_dwFileLen - m_Pos : 512);
+        pHints->AddSegment(m_Pos, iSize);
+        m_docStatus = PDF_DATAAVAIL_CROSSREF_ITEM;
+        return FALSE;
+      }
+
+      if (token == "trailer") {
+        m_dwTrailerOffset = m_Pos;
+        m_docStatus = PDF_DATAAVAIL_TRAILER;
+        return TRUE;
+      }
+    }
+  } else {
+    m_docStatus = PDF_DATAAVAIL_LOADALLFILE;
+    return TRUE;
+  }
+  return FALSE;
+}
+
+FX_BOOL CPDF_DataAvail::CheckTrailerAppend(DownloadHints* pHints) {
+  if (m_Pos < m_dwFileLen) {
+    FX_FILESIZE dwAppendPos = m_Pos + m_syntaxParser.SavePos();
+    int32_t iSize = (int32_t)(
+        dwAppendPos + 512 > m_dwFileLen ? m_dwFileLen - dwAppendPos : 512);
+
+    if (!m_pFileAvail->IsDataAvail(dwAppendPos, iSize)) {
+      pHints->AddSegment(dwAppendPos, iSize);
+      return FALSE;
+    }
+  }
+
+  if (m_dwPrevXRefOffset) {
+    SetStartOffset(m_dwPrevXRefOffset);
+    m_docStatus = PDF_DATAAVAIL_CROSSREF;
+  } else {
+    m_docStatus = PDF_DATAAVAIL_LOADALLCROSSREF;
+  }
+  return TRUE;
+}
+
+FX_BOOL CPDF_DataAvail::CheckTrailer(DownloadHints* pHints) {
+  int32_t iTrailerSize =
+      (int32_t)(m_Pos + 512 > m_dwFileLen ? m_dwFileLen - m_Pos : 512);
+  if (m_pFileAvail->IsDataAvail(m_Pos, iTrailerSize)) {
+    int32_t iSize = (int32_t)(m_Pos + iTrailerSize - m_dwTrailerOffset);
+    CFX_BinaryBuf buf(iSize);
+    uint8_t* pBuf = buf.GetBuffer();
+    if (!pBuf) {
+      m_docStatus = PDF_DATAAVAIL_ERROR;
+      return FALSE;
+    }
+
+    if (!m_pFileRead->ReadBlock(pBuf, m_dwTrailerOffset, iSize))
+      return FALSE;
+
+    ScopedFileStream file(FX_CreateMemoryStream(pBuf, (size_t)iSize, FALSE));
+    m_syntaxParser.InitParser(file.get(), 0);
+
+    std::unique_ptr<CPDF_Object, ReleaseDeleter<CPDF_Object>> pTrailer(
+        m_syntaxParser.GetObject(nullptr, 0, 0, true));
+    if (!pTrailer) {
+      m_Pos += m_syntaxParser.SavePos();
+      pHints->AddSegment(m_Pos, iTrailerSize);
+      return FALSE;
+    }
+
+    if (!pTrailer->IsDictionary())
+      return FALSE;
+
+    CPDF_Dictionary* pTrailerDict = pTrailer->GetDict();
+    CPDF_Object* pEncrypt = pTrailerDict->GetObjectFor("Encrypt");
+    if (ToReference(pEncrypt)) {
+      m_docStatus = PDF_DATAAVAIL_LOADALLFILE;
+      return TRUE;
+    }
+
+    uint32_t xrefpos = GetDirectInteger(pTrailerDict, "Prev");
+    if (xrefpos) {
+      m_dwPrevXRefOffset = GetDirectInteger(pTrailerDict, "XRefStm");
+      if (m_dwPrevXRefOffset) {
+        m_docStatus = PDF_DATAAVAIL_LOADALLFILE;
+      } else {
+        m_dwPrevXRefOffset = xrefpos;
+        if (m_dwPrevXRefOffset >= m_dwFileLen) {
+          m_docStatus = PDF_DATAAVAIL_LOADALLFILE;
+        } else {
+          SetStartOffset(m_dwPrevXRefOffset);
+          m_docStatus = PDF_DATAAVAIL_TRAILER_APPEND;
+        }
+      }
+      return TRUE;
+    }
+    m_dwPrevXRefOffset = 0;
+    m_docStatus = PDF_DATAAVAIL_TRAILER_APPEND;
+    return TRUE;
+  }
+  pHints->AddSegment(m_Pos, iTrailerSize);
+  return FALSE;
+}
+
+FX_BOOL CPDF_DataAvail::CheckPage(uint32_t dwPage, DownloadHints* pHints) {
+  while (TRUE) {
+    switch (m_docStatus) {
+      case PDF_DATAAVAIL_PAGETREE:
+        if (!LoadDocPages(pHints))
+          return FALSE;
+        break;
+      case PDF_DATAAVAIL_PAGE:
+        if (!LoadDocPage(dwPage, pHints))
+          return FALSE;
+        break;
+      case PDF_DATAAVAIL_ERROR:
+        return LoadAllFile(pHints);
+      default:
+        m_bPagesTreeLoad = TRUE;
+        m_bPagesLoad = TRUE;
+        m_bCurPageDictLoadOK = TRUE;
+        m_docStatus = PDF_DATAAVAIL_PAGE;
+        return TRUE;
+    }
+  }
+}
+
+FX_BOOL CPDF_DataAvail::CheckArrayPageNode(uint32_t dwPageNo,
+                                           PageNode* pPageNode,
+                                           DownloadHints* pHints) {
+  FX_BOOL bExist = FALSE;
+  CPDF_Object* pPages = GetObject(dwPageNo, pHints, &bExist);
+  if (!bExist) {
+    m_docStatus = PDF_DATAAVAIL_ERROR;
+    return FALSE;
+  }
+
+  if (!pPages) {
+    if (m_docStatus == PDF_DATAAVAIL_ERROR) {
+      m_docStatus = PDF_DATAAVAIL_ERROR;
+      return FALSE;
+    }
+    return FALSE;
+  }
+
+  CPDF_Array* pArray = pPages->AsArray();
+  if (!pArray) {
+    pPages->Release();
+    m_docStatus = PDF_DATAAVAIL_ERROR;
+    return FALSE;
+  }
+
+  pPageNode->m_type = PDF_PAGENODE_PAGES;
+  for (size_t i = 0; i < pArray->GetCount(); ++i) {
+    CPDF_Reference* pKid = ToReference(pArray->GetObjectAt(i));
+    if (!pKid)
+      continue;
+
+    PageNode* pNode = new PageNode();
+    pPageNode->m_childNode.Add(pNode);
+    pNode->m_dwPageNo = pKid->GetRefObjNum();
+  }
+  pPages->Release();
+  return TRUE;
+}
+
+FX_BOOL CPDF_DataAvail::CheckUnkownPageNode(uint32_t dwPageNo,
+                                            PageNode* pPageNode,
+                                            DownloadHints* pHints) {
+  FX_BOOL bExist = FALSE;
+  CPDF_Object* pPage = GetObject(dwPageNo, pHints, &bExist);
+  if (!bExist) {
+    m_docStatus = PDF_DATAAVAIL_ERROR;
+    return FALSE;
+  }
+
+  if (!pPage) {
+    if (m_docStatus == PDF_DATAAVAIL_ERROR)
+      m_docStatus = PDF_DATAAVAIL_ERROR;
+    return FALSE;
+  }
+
+  if (pPage->IsArray()) {
+    pPageNode->m_dwPageNo = dwPageNo;
+    pPageNode->m_type = PDF_PAGENODE_ARRAY;
+    pPage->Release();
+    return TRUE;
+  }
+
+  if (!pPage->IsDictionary()) {
+    pPage->Release();
+    m_docStatus = PDF_DATAAVAIL_ERROR;
+    return FALSE;
+  }
+
+  pPageNode->m_dwPageNo = dwPageNo;
+  CPDF_Dictionary* pDict = pPage->GetDict();
+  CFX_ByteString type = pDict->GetStringFor("Type");
+  if (type == "Pages") {
+    pPageNode->m_type = PDF_PAGENODE_PAGES;
+    CPDF_Object* pKids = pDict->GetObjectFor("Kids");
+    if (!pKids) {
+      m_docStatus = PDF_DATAAVAIL_PAGE;
+      return TRUE;
+    }
+
+    switch (pKids->GetType()) {
+      case CPDF_Object::REFERENCE: {
+        CPDF_Reference* pKid = pKids->AsReference();
+        PageNode* pNode = new PageNode();
+        pPageNode->m_childNode.Add(pNode);
+        pNode->m_dwPageNo = pKid->GetRefObjNum();
+      } break;
+      case CPDF_Object::ARRAY: {
+        CPDF_Array* pKidsArray = pKids->AsArray();
+        for (size_t i = 0; i < pKidsArray->GetCount(); ++i) {
+          CPDF_Reference* pKid = ToReference(pKidsArray->GetObjectAt(i));
+          if (!pKid)
+            continue;
+
+          PageNode* pNode = new PageNode();
+          pPageNode->m_childNode.Add(pNode);
+          pNode->m_dwPageNo = pKid->GetRefObjNum();
+        }
+      } break;
+      default:
+        break;
+    }
+  } else if (type == "Page") {
+    pPageNode->m_type = PDF_PAGENODE_PAGE;
+  } else {
+    pPage->Release();
+    m_docStatus = PDF_DATAAVAIL_ERROR;
+    return FALSE;
+  }
+  pPage->Release();
+  return TRUE;
+}
+
+FX_BOOL CPDF_DataAvail::CheckPageNode(CPDF_DataAvail::PageNode& pageNodes,
+                                      int32_t iPage,
+                                      int32_t& iCount,
+                                      DownloadHints* pHints,
+                                      int level) {
+  if (level >= kMaxPageRecursionDepth)
+    return FALSE;
+
+  int32_t iSize = pageNodes.m_childNode.GetSize();
+  if (iSize <= 0 || iPage >= iSize) {
+    m_docStatus = PDF_DATAAVAIL_ERROR;
+    return FALSE;
+  }
+
+  for (int32_t i = 0; i < iSize; ++i) {
+    PageNode* pNode = pageNodes.m_childNode.GetAt(i);
+    if (!pNode)
+      continue;
+
+    switch (pNode->m_type) {
+      case PDF_PAGENODE_UNKNOWN:
+        if (!CheckUnkownPageNode(pNode->m_dwPageNo, pNode, pHints)) {
+          return FALSE;
+        }
+        --i;
+        break;
+      case PDF_PAGENODE_PAGE:
+        iCount++;
+        if (iPage == iCount && m_pDocument)
+          m_pDocument->SetPageObjNum(iPage, pNode->m_dwPageNo);
+        break;
+      case PDF_PAGENODE_PAGES:
+        if (!CheckPageNode(*pNode, iPage, iCount, pHints, level + 1))
+          return FALSE;
+        break;
+      case PDF_PAGENODE_ARRAY:
+        if (!CheckArrayPageNode(pNode->m_dwPageNo, pNode, pHints))
+          return FALSE;
+        --i;
+        break;
+    }
+
+    if (iPage == iCount) {
+      m_docStatus = PDF_DATAAVAIL_DONE;
+      return TRUE;
+    }
+  }
+  return TRUE;
+}
+
+FX_BOOL CPDF_DataAvail::LoadDocPage(uint32_t dwPage, DownloadHints* pHints) {
+  FX_SAFE_INT32 safePage = pdfium::base::checked_cast<int32_t>(dwPage);
+  int32_t iPage = safePage.ValueOrDie();
+  if (m_pDocument->GetPageCount() <= iPage ||
+      m_pDocument->IsPageLoaded(iPage)) {
+    m_docStatus = PDF_DATAAVAIL_DONE;
+    return TRUE;
+  }
+
+  if (m_pageNodes.m_type == PDF_PAGENODE_PAGE) {
+    if (iPage == 0) {
+      m_docStatus = PDF_DATAAVAIL_DONE;
+      return TRUE;
+    }
+    m_docStatus = PDF_DATAAVAIL_ERROR;
+    return TRUE;
+  }
+  int32_t iCount = -1;
+  return CheckPageNode(m_pageNodes, iPage, iCount, pHints, 0);
+}
+
+FX_BOOL CPDF_DataAvail::CheckPageCount(DownloadHints* pHints) {
+  FX_BOOL bExist = FALSE;
+  CPDF_Object* pPages = GetObject(m_PagesObjNum, pHints, &bExist);
+  if (!bExist) {
+    m_docStatus = PDF_DATAAVAIL_ERROR;
+    return FALSE;
+  }
+
+  if (!pPages)
+    return FALSE;
+
+  CPDF_Dictionary* pPagesDict = pPages->GetDict();
+  if (!pPagesDict) {
+    pPages->Release();
+    m_docStatus = PDF_DATAAVAIL_ERROR;
+    return FALSE;
+  }
+
+  if (!pPagesDict->KeyExist("Kids")) {
+    pPages->Release();
+    return TRUE;
+  }
+
+  int count = pPagesDict->GetIntegerFor("Count");
+  if (count > 0) {
+    pPages->Release();
+    return TRUE;
+  }
+
+  pPages->Release();
+  return FALSE;
+}
+
+FX_BOOL CPDF_DataAvail::LoadDocPages(DownloadHints* pHints) {
+  if (!CheckUnkownPageNode(m_PagesObjNum, &m_pageNodes, pHints))
+    return FALSE;
+
+  if (CheckPageCount(pHints)) {
+    m_docStatus = PDF_DATAAVAIL_PAGE;
+    return TRUE;
+  }
+
+  m_bTotalLoadPageTree = TRUE;
+  return FALSE;
+}
+
+FX_BOOL CPDF_DataAvail::LoadPages(DownloadHints* pHints) {
+  while (!m_bPagesTreeLoad) {
+    if (!CheckPageStatus(pHints))
+      return FALSE;
+  }
+
+  if (m_bPagesLoad)
+    return TRUE;
+
+  m_pDocument->LoadPages();
+  return FALSE;
+}
+
+CPDF_DataAvail::DocAvailStatus CPDF_DataAvail::CheckLinearizedData(
+    DownloadHints* pHints) {
+  if (m_bLinearedDataOK)
+    return DataAvailable;
+
+  if (!m_bMainXRefLoadTried) {
+    FX_SAFE_UINT32 data_size = m_dwFileLen;
+    data_size -= m_dwLastXRefOffset;
+    if (!data_size.IsValid())
+      return DataError;
+
+    if (!m_pFileAvail->IsDataAvail(m_dwLastXRefOffset,
+                                   data_size.ValueOrDie())) {
+      pHints->AddSegment(m_dwLastXRefOffset, data_size.ValueOrDie());
+      return DataNotAvailable;
+    }
+
+    CPDF_Parser::Error eRet =
+        m_pDocument->GetParser()->LoadLinearizedMainXRefTable();
+    m_bMainXRefLoadTried = TRUE;
+    if (eRet != CPDF_Parser::SUCCESS)
+      return DataError;
+
+    if (!PreparePageItem())
+      return DataNotAvailable;
+
+    m_bMainXRefLoadedOK = TRUE;
+    m_bLinearedDataOK = TRUE;
+  }
+
+  return m_bLinearedDataOK ? DataAvailable : DataNotAvailable;
+}
+
+FX_BOOL CPDF_DataAvail::CheckPageAnnots(uint32_t dwPage,
+                                        DownloadHints* pHints) {
+  if (!m_objs_array.GetSize()) {
+    m_objs_array.RemoveAll();
+    m_ObjectSet.clear();
+
+    FX_SAFE_INT32 safePage = pdfium::base::checked_cast<int32_t>(dwPage);
+    CPDF_Dictionary* pPageDict = m_pDocument->GetPage(safePage.ValueOrDie());
+    if (!pPageDict)
+      return TRUE;
+
+    CPDF_Object* pAnnots = pPageDict->GetObjectFor("Annots");
+    if (!pAnnots)
+      return TRUE;
+
+    CFX_ArrayTemplate<CPDF_Object*> obj_array;
+    obj_array.Add(pAnnots);
+
+    FX_BOOL bRet = IsObjectsAvail(obj_array, FALSE, pHints, m_objs_array);
+    if (bRet)
+      m_objs_array.RemoveAll();
+
+    return bRet;
+  }
+
+  CFX_ArrayTemplate<CPDF_Object*> new_objs_array;
+  FX_BOOL bRet = IsObjectsAvail(m_objs_array, FALSE, pHints, new_objs_array);
+  m_objs_array.RemoveAll();
+  if (!bRet)
+    m_objs_array.Append(new_objs_array);
+
+  return bRet;
+}
+
+CPDF_DataAvail::DocAvailStatus CPDF_DataAvail::CheckLinearizedFirstPage(
+    uint32_t dwPage,
+    DownloadHints* pHints) {
+  if (!m_bAnnotsLoad) {
+    if (!CheckPageAnnots(dwPage, pHints))
+      return DataNotAvailable;
+    m_bAnnotsLoad = TRUE;
+  }
+
+  DocAvailStatus nRet = CheckLinearizedData(pHints);
+  if (nRet == DataAvailable)
+    m_bPageLoadedOK = FALSE;
+  return nRet;
+}
+
+FX_BOOL CPDF_DataAvail::HaveResourceAncestor(CPDF_Dictionary* pDict) {
+  CFX_AutoRestorer<int> restorer(&s_CurrentDataAvailRecursionDepth);
+  if (++s_CurrentDataAvailRecursionDepth > kMaxDataAvailRecursionDepth)
+    return FALSE;
+
+  CPDF_Object* pParent = pDict->GetObjectFor("Parent");
+  if (!pParent)
+    return FALSE;
+
+  CPDF_Dictionary* pParentDict = pParent->GetDict();
+  if (!pParentDict)
+    return FALSE;
+
+  CPDF_Object* pRet = pParentDict->GetObjectFor("Resources");
+  if (pRet) {
+    m_pPageResource = pRet;
+    return TRUE;
+  }
+
+  return HaveResourceAncestor(pParentDict);
+}
+
+CPDF_DataAvail::DocAvailStatus CPDF_DataAvail::IsPageAvail(
+    uint32_t dwPage,
+    DownloadHints* pHints) {
+  if (!m_pDocument)
+    return DataError;
+
+  if (IsFirstCheck(dwPage)) {
+    m_bCurPageDictLoadOK = FALSE;
+    m_bPageLoadedOK = FALSE;
+    m_bAnnotsLoad = FALSE;
+    m_bNeedDownLoadResource = FALSE;
+    m_objs_array.RemoveAll();
+    m_ObjectSet.clear();
+  }
+
+  if (pdfium::ContainsKey(m_pagesLoadState, dwPage))
+    return DataAvailable;
+
+  if (m_bLinearized) {
+    if (dwPage == m_dwFirstPageNo) {
+      DocAvailStatus nRet = CheckLinearizedFirstPage(dwPage, pHints);
+      if (nRet == DataAvailable)
+        m_pagesLoadState.insert(dwPage);
+      return nRet;
+    }
+
+    DocAvailStatus nResult = CheckLinearizedData(pHints);
+    if (nResult != DataAvailable)
+      return nResult;
+
+    if (m_pHintTables) {
+      nResult = m_pHintTables->CheckPage(dwPage, pHints);
+      if (nResult != DataAvailable)
+        return nResult;
+      m_pagesLoadState.insert(dwPage);
+      return DataAvailable;
+    }
+
+    if (m_bMainXRefLoadedOK) {
+      if (m_bTotalLoadPageTree) {
+        if (!LoadPages(pHints))
+          return DataNotAvailable;
+      } else {
+        if (!m_bCurPageDictLoadOK && !CheckPage(dwPage, pHints))
+          return DataNotAvailable;
+      }
+    } else {
+      if (!LoadAllFile(pHints))
+        return DataNotAvailable;
+      m_pDocument->GetParser()->RebuildCrossRef();
+      ResetFirstCheck(dwPage);
+      return DataAvailable;
+    }
+  } else {
+    if (!m_bTotalLoadPageTree && !m_bCurPageDictLoadOK &&
+        !CheckPage(dwPage, pHints)) {
+      return DataNotAvailable;
+    }
+  }
+
+  if (m_bHaveAcroForm && !m_bAcroFormLoad) {
+    if (!CheckAcroFormSubObject(pHints))
+      return DataNotAvailable;
+    m_bAcroFormLoad = TRUE;
+  }
+
+  if (!m_bPageLoadedOK) {
+    if (!m_objs_array.GetSize()) {
+      m_objs_array.RemoveAll();
+      m_ObjectSet.clear();
+
+      FX_SAFE_INT32 safePage = pdfium::base::checked_cast<int32_t>(dwPage);
+      m_pPageDict = m_pDocument->GetPage(safePage.ValueOrDie());
+      if (!m_pPageDict) {
+        ResetFirstCheck(dwPage);
+        return DataAvailable;
+      }
+
+      CFX_ArrayTemplate<CPDF_Object*> obj_array;
+      obj_array.Add(m_pPageDict);
+      FX_BOOL bRet = IsObjectsAvail(obj_array, TRUE, pHints, m_objs_array);
+      if (!bRet)
+        return DataNotAvailable;
+
+      m_objs_array.RemoveAll();
+    } else {
+      CFX_ArrayTemplate<CPDF_Object*> new_objs_array;
+      FX_BOOL bRet =
+          IsObjectsAvail(m_objs_array, FALSE, pHints, new_objs_array);
+
+      m_objs_array.RemoveAll();
+      if (!bRet) {
+        m_objs_array.Append(new_objs_array);
+        return DataNotAvailable;
+      }
+    }
+    m_bPageLoadedOK = TRUE;
+  }
+
+  if (!m_bAnnotsLoad) {
+    if (!CheckPageAnnots(dwPage, pHints))
+      return DataNotAvailable;
+    m_bAnnotsLoad = TRUE;
+  }
+
+  if (m_pPageDict && !m_bNeedDownLoadResource) {
+    m_pPageResource = m_pPageDict->GetObjectFor("Resources");
+    m_bNeedDownLoadResource =
+        m_pPageResource || HaveResourceAncestor(m_pPageDict);
+  }
+
+  if (m_bNeedDownLoadResource) {
+    if (!CheckResources(pHints))
+      return DataNotAvailable;
+    m_bNeedDownLoadResource = FALSE;
+  }
+
+  m_bPageLoadedOK = FALSE;
+  m_bAnnotsLoad = FALSE;
+  m_bCurPageDictLoadOK = FALSE;
+
+  ResetFirstCheck(dwPage);
+  m_pagesLoadState.insert(dwPage);
+  return DataAvailable;
+}
+
+FX_BOOL CPDF_DataAvail::CheckResources(DownloadHints* pHints) {
+  if (!m_objs_array.GetSize()) {
+    m_objs_array.RemoveAll();
+    CFX_ArrayTemplate<CPDF_Object*> obj_array;
+    obj_array.Add(m_pPageResource);
+
+    FX_BOOL bRet = IsObjectsAvail(obj_array, TRUE, pHints, m_objs_array);
+    if (bRet)
+      m_objs_array.RemoveAll();
+    return bRet;
+  }
+
+  CFX_ArrayTemplate<CPDF_Object*> new_objs_array;
+  FX_BOOL bRet = IsObjectsAvail(m_objs_array, FALSE, pHints, new_objs_array);
+  m_objs_array.RemoveAll();
+  if (!bRet)
+    m_objs_array.Append(new_objs_array);
+  return bRet;
+}
+
+void CPDF_DataAvail::GetLinearizedMainXRefInfo(FX_FILESIZE* pPos,
+                                               uint32_t* pSize) {
+  if (pPos)
+    *pPos = m_dwLastXRefOffset;
+  if (pSize)
+    *pSize = (uint32_t)(m_dwFileLen - m_dwLastXRefOffset);
+}
+
+int CPDF_DataAvail::GetPageCount() const {
+  if (m_pLinearized) {
+    CPDF_Dictionary* pDict = m_pLinearized->GetDict();
+    CPDF_Object* pObj = pDict ? pDict->GetDirectObjectFor("N") : nullptr;
+    return pObj ? pObj->GetInteger() : 0;
+  }
+  return m_pDocument ? m_pDocument->GetPageCount() : 0;
+}
+
+CPDF_Dictionary* CPDF_DataAvail::GetPage(int index) {
+  if (!m_pDocument || index < 0 || index >= GetPageCount())
+    return nullptr;
+
+  if (m_pLinearized) {
+    CPDF_Dictionary* pDict = m_pLinearized->GetDict();
+    CPDF_Object* pObj = pDict ? pDict->GetDirectObjectFor("P") : nullptr;
+
+    int pageNum = pObj ? pObj->GetInteger() : 0;
+    if (m_pHintTables && index != pageNum) {
+      FX_FILESIZE szPageStartPos = 0;
+      FX_FILESIZE szPageLength = 0;
+      uint32_t dwObjNum = 0;
+      bool bPagePosGot = m_pHintTables->GetPagePos(index, &szPageStartPos,
+                                                   &szPageLength, &dwObjNum);
+      if (!bPagePosGot)
+        return nullptr;
+
+      m_syntaxParser.InitParser(m_pFileRead, (uint32_t)szPageStartPos);
+      CPDF_Object* pPageDict = ParseIndirectObjectAt(0, dwObjNum, m_pDocument);
+      if (!pPageDict)
+        return nullptr;
+
+      if (!m_pDocument->ReplaceIndirectObjectIfHigherGeneration(dwObjNum,
+                                                                pPageDict)) {
+        return nullptr;
+      }
+      return pPageDict->GetDict();
+    }
+  }
+  return m_pDocument->GetPage(index);
+}
+
+CPDF_DataAvail::DocFormStatus CPDF_DataAvail::IsFormAvail(
+    DownloadHints* pHints) {
+  if (!m_pDocument)
+    return FormAvailable;
+
+  if (!m_bLinearizedFormParamLoad) {
+    CPDF_Dictionary* pRoot = m_pDocument->GetRoot();
+    if (!pRoot)
+      return FormAvailable;
+
+    CPDF_Object* pAcroForm = pRoot->GetObjectFor("AcroForm");
+    if (!pAcroForm)
+      return FormNotExist;
+
+    DocAvailStatus nDocStatus = CheckLinearizedData(pHints);
+    if (nDocStatus == DataError)
+      return FormError;
+    if (nDocStatus == DataNotAvailable)
+      return FormNotAvailable;
+
+    if (!m_objs_array.GetSize())
+      m_objs_array.Add(pAcroForm->GetDict());
+    m_bLinearizedFormParamLoad = TRUE;
+  }
+
+  CFX_ArrayTemplate<CPDF_Object*> new_objs_array;
+  FX_BOOL bRet = IsObjectsAvail(m_objs_array, FALSE, pHints, new_objs_array);
+  m_objs_array.RemoveAll();
+  if (!bRet) {
+    m_objs_array.Append(new_objs_array);
+    return FormNotAvailable;
+  }
+  return FormAvailable;
+}
+
+CPDF_DataAvail::PageNode::PageNode() : m_type(PDF_PAGENODE_UNKNOWN) {}
+
+CPDF_DataAvail::PageNode::~PageNode() {
+  for (int32_t i = 0; i < m_childNode.GetSize(); ++i)
+    delete m_childNode[i];
+  m_childNode.RemoveAll();
+}
diff --git a/core/fpdfapi/parser/cpdf_data_avail.h b/core/fpdfapi/parser/cpdf_data_avail.h
new file mode 100644
index 0000000000..f4fb753d1d
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_data_avail.h
@@ -0,0 +1,253 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#ifndef CORE_FPDFAPI_PARSER_CPDF_DATA_AVAIL_H_
+#define CORE_FPDFAPI_PARSER_CPDF_DATA_AVAIL_H_
+
+#include "core/fpdfapi/parser/cpdf_parser.h"
+#include "core/fpdfapi/parser/cpdf_syntax_parser.h"
+#include "core/fxcrt/fx_basic.h"
+
+class CPDF_Dictionary;
+class CPDF_HintTables;
+class CPDF_IndirectObjectHolder;
+class CPDF_Parser;
+
+enum PDF_DATAAVAIL_STATUS {
+  PDF_DATAAVAIL_HEADER = 0,
+  PDF_DATAAVAIL_FIRSTPAGE,
+  PDF_DATAAVAIL_FIRSTPAGE_PREPARE,
+  PDF_DATAAVAIL_HINTTABLE,
+  PDF_DATAAVAIL_END,
+  PDF_DATAAVAIL_CROSSREF,
+  PDF_DATAAVAIL_CROSSREF_ITEM,
+  PDF_DATAAVAIL_CROSSREF_STREAM,
+  PDF_DATAAVAIL_TRAILER,
+  PDF_DATAAVAIL_LOADALLCROSSREF,
+  PDF_DATAAVAIL_ROOT,
+  PDF_DATAAVAIL_INFO,
+  PDF_DATAAVAIL_ACROFORM,
+  PDF_DATAAVAIL_ACROFORM_SUBOBJECT,
+  PDF_DATAAVAIL_PAGETREE,
+  PDF_DATAAVAIL_PAGE,
+  PDF_DATAAVAIL_PAGE_LATERLOAD,
+  PDF_DATAAVAIL_RESOURCES,
+  PDF_DATAAVAIL_DONE,
+  PDF_DATAAVAIL_ERROR,
+  PDF_DATAAVAIL_LOADALLFILE,
+  PDF_DATAAVAIL_TRAILER_APPEND
+};
+
+enum PDF_PAGENODE_TYPE {
+  PDF_PAGENODE_UNKNOWN = 0,
+  PDF_PAGENODE_PAGE,
+  PDF_PAGENODE_PAGES,
+  PDF_PAGENODE_ARRAY,
+};
+
+class CPDF_DataAvail final {
+ public:
+  // Must match PDF_DATA_* definitions in public/fpdf_dataavail.h, but cannot
+  // #include that header. fpdfsdk/fpdf_dataavail.cpp has static_asserts
+  // to make sure the two sets of values match.
+  enum DocAvailStatus {
+    DataError = -1,        // PDF_DATA_ERROR
+    DataNotAvailable = 0,  // PDF_DATA_NOTAVAIL
+    DataAvailable = 1,     // PDF_DATA_AVAIL
+  };
+
+  // Must match PDF_*LINEAR* definitions in public/fpdf_dataavail.h, but cannot
+  // #include that header. fpdfsdk/fpdf_dataavail.cpp has static_asserts
+  // to make sure the two sets of values match.
+  enum DocLinearizationStatus {
+    LinearizationUnknown = -1,  // PDF_LINEARIZATION_UNKNOWN
+    NotLinearized = 0,          // PDF_NOT_LINEARIZED
+    Linearized = 1,             // PDF_LINEARIZED
+  };
+
+  // Must match PDF_FORM_* definitions in public/fpdf_dataavail.h, but cannot
+  // #include that header. fpdfsdk/fpdf_dataavail.cpp has static_asserts
+  // to make sure the two sets of values match.
+  enum DocFormStatus {
+    FormError = -1,        // PDF_FORM_ERROR
+    FormNotAvailable = 0,  // PDF_FORM_NOTAVAIL
+    FormAvailable = 1,     // PDF_FORM_AVAIL
+    FormNotExist = 2,      // PDF_FORM_NOTEXIST
+  };
+
+  class FileAvail {
+   public:
+    virtual ~FileAvail();
+    virtual FX_BOOL IsDataAvail(FX_FILESIZE offset, uint32_t size) = 0;
+  };
+
+  class DownloadHints {
+   public:
+    virtual ~DownloadHints();
+    virtual void AddSegment(FX_FILESIZE offset, uint32_t size) = 0;
+  };
+
+  CPDF_DataAvail(FileAvail* pFileAvail,
+                 IFX_FileRead* pFileRead,
+                 FX_BOOL bSupportHintTable);
+  ~CPDF_DataAvail();
+
+  DocAvailStatus IsDocAvail(DownloadHints* pHints);
+  void SetDocument(CPDF_Document* pDoc);
+  DocAvailStatus IsPageAvail(uint32_t dwPage, DownloadHints* pHints);
+  DocFormStatus IsFormAvail(DownloadHints* pHints);
+  DocLinearizationStatus IsLinearizedPDF();
+  FX_BOOL IsLinearized();
+  void GetLinearizedMainXRefInfo(FX_FILESIZE* pPos, uint32_t* pSize);
+  IFX_FileRead* GetFileRead() const { return m_pFileRead; }
+  int GetPageCount() const;
+  CPDF_Dictionary* GetPage(int index);
+
+  friend class CPDF_HintTables;
+
+ protected:
+  class PageNode {
+   public:
+    PageNode();
+    ~PageNode();
+
+    PDF_PAGENODE_TYPE m_type;
+    uint32_t m_dwPageNo;
+    CFX_ArrayTemplate<PageNode*> m_childNode;
+  };
+
+  static const int kMaxDataAvailRecursionDepth = 64;
+  static int s_CurrentDataAvailRecursionDepth;
+  static const int kMaxPageRecursionDepth = 1024;
+
+  uint32_t GetObjectSize(uint32_t objnum, FX_FILESIZE& offset);
+  FX_BOOL IsObjectsAvail(CFX_ArrayTemplate<CPDF_Object*>& obj_array,
+                         FX_BOOL bParsePage,
+                         DownloadHints* pHints,
+                         CFX_ArrayTemplate<CPDF_Object*>& ret_array);
+  FX_BOOL CheckDocStatus(DownloadHints* pHints);
+  FX_BOOL CheckHeader(DownloadHints* pHints);
+  FX_BOOL CheckFirstPage(DownloadHints* pHints);
+  FX_BOOL CheckHintTables(DownloadHints* pHints);
+  FX_BOOL CheckEnd(DownloadHints* pHints);
+  FX_BOOL CheckCrossRef(DownloadHints* pHints);
+  FX_BOOL CheckCrossRefItem(DownloadHints* pHints);
+  FX_BOOL CheckTrailer(DownloadHints* pHints);
+  FX_BOOL CheckRoot(DownloadHints* pHints);
+  FX_BOOL CheckInfo(DownloadHints* pHints);
+  FX_BOOL CheckPages(DownloadHints* pHints);
+  FX_BOOL CheckPage(DownloadHints* pHints);
+  FX_BOOL CheckResources(DownloadHints* pHints);
+  FX_BOOL CheckAnnots(DownloadHints* pHints);
+  FX_BOOL CheckAcroForm(DownloadHints* pHints);
+  FX_BOOL CheckAcroFormSubObject(DownloadHints* pHints);
+  FX_BOOL CheckTrailerAppend(DownloadHints* pHints);
+  FX_BOOL CheckPageStatus(DownloadHints* pHints);
+  FX_BOOL CheckAllCrossRefStream(DownloadHints* pHints);
+
+  int32_t CheckCrossRefStream(DownloadHints* pHints, FX_FILESIZE& xref_offset);
+  FX_BOOL IsLinearizedFile(uint8_t* pData, uint32_t dwLen);
+  void SetStartOffset(FX_FILESIZE dwOffset);
+  FX_BOOL GetNextToken(CFX_ByteString& token);
+  FX_BOOL GetNextChar(uint8_t& ch);
+  CPDF_Object* ParseIndirectObjectAt(
+      FX_FILESIZE pos,
+      uint32_t objnum,
+      CPDF_IndirectObjectHolder* pObjList = nullptr);
+  CPDF_Object* GetObject(uint32_t objnum,
+                         DownloadHints* pHints,
+                         FX_BOOL* pExistInFile);
+  FX_BOOL GetPageKids(CPDF_Parser* pParser, CPDF_Object* pPages);
+  FX_BOOL PreparePageItem();
+  FX_BOOL LoadPages(DownloadHints* pHints);
+  FX_BOOL LoadAllXref(DownloadHints* pHints);
+  FX_BOOL LoadAllFile(DownloadHints* pHints);
+  DocAvailStatus CheckLinearizedData(DownloadHints* pHints);
+  FX_BOOL CheckPageAnnots(uint32_t dwPage, DownloadHints* pHints);
+
+  DocAvailStatus CheckLinearizedFirstPage(uint32_t dwPage,
+                                          DownloadHints* pHints);
+  FX_BOOL HaveResourceAncestor(CPDF_Dictionary* pDict);
+  FX_BOOL CheckPage(uint32_t dwPage, DownloadHints* pHints);
+  FX_BOOL LoadDocPages(DownloadHints* pHints);
+  FX_BOOL LoadDocPage(uint32_t dwPage, DownloadHints* pHints);
+  FX_BOOL CheckPageNode(PageNode& pageNodes,
+                        int32_t iPage,
+                        int32_t& iCount,
+                        DownloadHints* pHints,
+                        int level);
+  FX_BOOL CheckUnkownPageNode(uint32_t dwPageNo,
+                              PageNode* pPageNode,
+                              DownloadHints* pHints);
+  FX_BOOL CheckArrayPageNode(uint32_t dwPageNo,
+                             PageNode* pPageNode,
+                             DownloadHints* pHints);
+  FX_BOOL CheckPageCount(DownloadHints* pHints);
+  bool IsFirstCheck(uint32_t dwPage);
+  void ResetFirstCheck(uint32_t dwPage);
+  FX_BOOL IsDataAvail(FX_FILESIZE offset, uint32_t size, DownloadHints* pHints);
+
+  FileAvail* const m_pFileAvail;
+  IFX_FileRead* const m_pFileRead;
+  CPDF_Parser m_parser;
+  CPDF_SyntaxParser m_syntaxParser;
+  CPDF_Object* m_pRoot;
+  uint32_t m_dwRootObjNum;
+  uint32_t m_dwInfoObjNum;
+  CPDF_Object* m_pLinearized;
+  CPDF_Object* m_pTrailer;
+  FX_BOOL m_bDocAvail;
+  FX_FILESIZE m_dwHeaderOffset;
+  FX_FILESIZE m_dwLastXRefOffset;
+  FX_FILESIZE m_dwXRefOffset;
+  FX_FILESIZE m_dwTrailerOffset;
+  FX_FILESIZE m_dwCurrentOffset;
+  PDF_DATAAVAIL_STATUS m_docStatus;
+  FX_FILESIZE m_dwFileLen;
+  CPDF_Document* m_pDocument;
+  std::set<uint32_t> m_ObjectSet;
+  CFX_ArrayTemplate<CPDF_Object*> m_objs_array;
+  FX_FILESIZE m_Pos;
+  FX_FILESIZE m_bufferOffset;
+  uint32_t m_bufferSize;
+  CFX_ByteString m_WordBuf;
+  uint8_t m_bufferData[512];
+  CFX_ArrayTemplate<uint32_t> m_XRefStreamList;
+  CFX_ArrayTemplate<uint32_t> m_PageObjList;
+  uint32_t m_PagesObjNum;
+  FX_BOOL m_bLinearized;
+  uint32_t m_dwFirstPageNo;
+  FX_BOOL m_bLinearedDataOK;
+  FX_BOOL m_bMainXRefLoadTried;
+  FX_BOOL m_bMainXRefLoadedOK;
+  FX_BOOL m_bPagesTreeLoad;
+  FX_BOOL m_bPagesLoad;
+  CPDF_Parser* m_pCurrentParser;
+  FX_FILESIZE m_dwCurrentXRefSteam;
+  FX_BOOL m_bAnnotsLoad;
+  FX_BOOL m_bHaveAcroForm;
+  uint32_t m_dwAcroFormObjNum;
+  FX_BOOL m_bAcroFormLoad;
+  CPDF_Object* m_pAcroForm;
+  CFX_ArrayTemplate<CPDF_Object*> m_arrayAcroforms;
+  CPDF_Dictionary* m_pPageDict;
+  CPDF_Object* m_pPageResource;
+  FX_BOOL m_bNeedDownLoadResource;
+  FX_BOOL m_bPageLoadedOK;
+  FX_BOOL m_bLinearizedFormParamLoad;
+  CFX_ArrayTemplate<CPDF_Object*> m_PagesArray;
+  uint32_t m_dwEncryptObjNum;
+  FX_FILESIZE m_dwPrevXRefOffset;
+  FX_BOOL m_bTotalLoadPageTree;
+  FX_BOOL m_bCurPageDictLoadOK;
+  PageNode m_pageNodes;
+  std::set<uint32_t> m_pageMapCheckState;
+  std::set<uint32_t> m_pagesLoadState;
+  std::unique_ptr<CPDF_HintTables> m_pHintTables;
+  FX_BOOL m_bSupportHintTable;
+};
+
+#endif  // CORE_FPDFAPI_PARSER_CPDF_DATA_AVAIL_H_
diff --git a/core/fpdfapi/parser/cpdf_dictionary.cpp b/core/fpdfapi/parser/cpdf_dictionary.cpp
new file mode 100644
index 0000000000..7601c5b831
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_dictionary.cpp
@@ -0,0 +1,275 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#include "core/fpdfapi/parser/cpdf_dictionary.h"
+
+#include <set>
+#include <utility>
+
+#include "core/fpdfapi/parser/cpdf_array.h"
+#include "core/fpdfapi/parser/cpdf_boolean.h"
+#include "core/fpdfapi/parser/cpdf_name.h"
+#include "core/fpdfapi/parser/cpdf_number.h"
+#include "core/fpdfapi/parser/cpdf_reference.h"
+#include "core/fpdfapi/parser/cpdf_stream.h"
+#include "core/fpdfapi/parser/cpdf_string.h"
+#include "third_party/base/logging.h"
+#include "third_party/base/stl_util.h"
+
+CPDF_Dictionary::CPDF_Dictionary()
+    : CPDF_Dictionary(CFX_WeakPtr<CFX_ByteStringPool>()) {}
+
+CPDF_Dictionary::CPDF_Dictionary(const CFX_WeakPtr<CFX_ByteStringPool>& pPool)
+    : m_pPool(pPool) {}
+
+CPDF_Dictionary::~CPDF_Dictionary() {
+  // Mark the object as deleted so that it will not be deleted again
+  // in case of cyclic references.
+  m_ObjNum = kInvalidObjNum;
+  for (const auto& it : m_Map) {
+    if (it.second)
+      it.second->Release();
+  }
+}
+
+CPDF_Object::Type CPDF_Dictionary::GetType() const {
+  return DICTIONARY;
+}
+
+CPDF_Dictionary* CPDF_Dictionary::GetDict() const {
+  // The method should be made non-const if we want to not be const.
+  // See bug #234.
+  return const_cast<CPDF_Dictionary*>(this);
+}
+
+bool CPDF_Dictionary::IsDictionary() const {
+  return true;
+}
+
+CPDF_Dictionary* CPDF_Dictionary::AsDictionary() {
+  return this;
+}
+
+const CPDF_Dictionary* CPDF_Dictionary::AsDictionary() const {
+  return this;
+}
+
+CPDF_Object* CPDF_Dictionary::Clone() const {
+  return CloneObjectNonCyclic(false);
+}
+
+CPDF_Object* CPDF_Dictionary::CloneNonCyclic(
+    bool bDirect,
+    std::set<const CPDF_Object*>* pVisited) const {
+  pVisited->insert(this);
+  CPDF_Dictionary* pCopy = new CPDF_Dictionary(m_pPool);
+  for (const auto& it : *this) {
+    CPDF_Object* value = it.second;
+    if (!pdfium::ContainsKey(*pVisited, value)) {
+      pCopy->m_Map.insert(
+          std::make_pair(it.first, value->CloneNonCyclic(bDirect, pVisited)));
+    }
+  }
+  return pCopy;
+}
+
+CPDF_Object* CPDF_Dictionary::GetObjectFor(const CFX_ByteString& key) const {
+  auto it = m_Map.find(key);
+  return it != m_Map.end() ? it->second : nullptr;
+}
+
+CPDF_Object* CPDF_Dictionary::GetDirectObjectFor(
+    const CFX_ByteString& key) const {
+  CPDF_Object* p = GetObjectFor(key);
+  return p ? p->GetDirect() : nullptr;
+}
+
+CFX_ByteString CPDF_Dictionary::GetStringFor(const CFX_ByteString& key) const {
+  CPDF_Object* p = GetObjectFor(key);
+  return p ? p->GetString() : CFX_ByteString();
+}
+
+CFX_WideString CPDF_Dictionary::GetUnicodeTextFor(
+    const CFX_ByteString& key) const {
+  CPDF_Object* p = GetObjectFor(key);
+  if (CPDF_Reference* pRef = ToReference(p))
+    p = pRef->GetDirect();
+  return p ? p->GetUnicodeText() : CFX_WideString();
+}
+
+CFX_ByteString CPDF_Dictionary::GetStringFor(const CFX_ByteString& key,
+                                             const CFX_ByteString& def) const {
+  CPDF_Object* p = GetObjectFor(key);
+  return p ? p->GetString() : CFX_ByteString(def);
+}
+
+int CPDF_Dictionary::GetIntegerFor(const CFX_ByteString& key) const {
+  CPDF_Object* p = GetObjectFor(key);
+  return p ? p->GetInteger() : 0;
+}
+
+int CPDF_Dictionary::GetIntegerFor(const CFX_ByteString& key, int def) const {
+  CPDF_Object* p = GetObjectFor(key);
+  return p ? p->GetInteger() : def;
+}
+
+FX_FLOAT CPDF_Dictionary::GetNumberFor(const CFX_ByteString& key) const {
+  CPDF_Object* p = GetObjectFor(key);
+  return p ? p->GetNumber() : 0;
+}
+
+bool CPDF_Dictionary::GetBooleanFor(const CFX_ByteString& key,
+                                    bool bDefault) const {
+  CPDF_Object* p = GetObjectFor(key);
+  return ToBoolean(p) ? p->GetInteger() != 0 : bDefault;
+}
+
+CPDF_Dictionary* CPDF_Dictionary::GetDictFor(const CFX_ByteString& key) const {
+  CPDF_Object* p = GetDirectObjectFor(key);
+  if (!p)
+    return nullptr;
+  if (CPDF_Dictionary* pDict = p->AsDictionary())
+    return pDict;
+  if (CPDF_Stream* pStream = p->AsStream())
+    return pStream->GetDict();
+  return nullptr;
+}
+
+CPDF_Array* CPDF_Dictionary::GetArrayFor(const CFX_ByteString& key) const {
+  return ToArray(GetDirectObjectFor(key));
+}
+
+CPDF_Stream* CPDF_Dictionary::GetStreamFor(const CFX_ByteString& key) const {
+  return ToStream(GetDirectObjectFor(key));
+}
+
+CFX_FloatRect CPDF_Dictionary::GetRectFor(const CFX_ByteString& key) const {
+  CFX_FloatRect rect;
+  CPDF_Array* pArray = GetArrayFor(key);
+  if (pArray)
+    rect = pArray->GetRect();
+  return rect;
+}
+
+CFX_Matrix CPDF_Dictionary::GetMatrixFor(const CFX_ByteString& key) const {
+  CFX_Matrix matrix;
+  CPDF_Array* pArray = GetArrayFor(key);
+  if (pArray)
+    matrix = pArray->GetMatrix();
+  return matrix;
+}
+
+FX_BOOL CPDF_Dictionary::KeyExist(const CFX_ByteString& key) const {
+  return pdfium::ContainsKey(m_Map, key);
+}
+
+bool CPDF_Dictionary::IsSignatureDict() const {
+  CPDF_Object* pType = GetDirectObjectFor("Type");
+  if (!pType)
+    pType = GetDirectObjectFor("FT");
+  return pType && pType->GetString() == "Sig";
+}
+
+void CPDF_Dictionary::SetFor(const CFX_ByteString& key, CPDF_Object* pObj) {
+  CHECK(!pObj || pObj->GetObjNum() == 0);
+  auto it = m_Map.find(key);
+  if (it == m_Map.end()) {
+    if (pObj)
+      m_Map.insert(std::make_pair(MaybeIntern(key), pObj));
+    return;
+  }
+
+  if (it->second == pObj)
+    return;
+  it->second->Release();
+
+  if (pObj)
+    it->second = pObj;
+  else
+    m_Map.erase(it);
+}
+
+void CPDF_Dictionary::RemoveFor(const CFX_ByteString& key) {
+  auto it = m_Map.find(key);
+  if (it == m_Map.end())
+    return;
+
+  it->second->Release();
+  m_Map.erase(it);
+}
+
+void CPDF_Dictionary::ReplaceKey(const CFX_ByteString& oldkey,
+                                 const CFX_ByteString& newkey) {
+  auto old_it = m_Map.find(oldkey);
+  if (old_it == m_Map.end())
+    return;
+
+  auto new_it = m_Map.find(newkey);
+  if (new_it == old_it)
+    return;
+
+  if (new_it != m_Map.end()) {
+    new_it->second->Release();
+    new_it->second = old_it->second;
+  } else {
+    m_Map.insert(std::make_pair(MaybeIntern(newkey), old_it->second));
+  }
+  m_Map.erase(old_it);
+}
+
+void CPDF_Dictionary::SetIntegerFor(const CFX_ByteString& key, int i) {
+  SetFor(key, new CPDF_Number(i));
+}
+
+void CPDF_Dictionary::SetNameFor(const CFX_ByteString& key,
+                                 const CFX_ByteString& name) {
+  SetFor(key, new CPDF_Name(MaybeIntern(name)));
+}
+
+void CPDF_Dictionary::SetStringFor(const CFX_ByteString& key,
+                                   const CFX_ByteString& str) {
+  SetFor(key, new CPDF_String(MaybeIntern(str), FALSE));
+}
+
+void CPDF_Dictionary::SetReferenceFor(const CFX_ByteString& key,
+                                      CPDF_IndirectObjectHolder* pDoc,
+                                      uint32_t objnum) {
+  SetFor(key, new CPDF_Reference(pDoc, objnum));
+}
+
+void CPDF_Dictionary::SetNumberFor(const CFX_ByteString& key, FX_FLOAT f) {
+  SetFor(key, new CPDF_Number(f));
+}
+
+void CPDF_Dictionary::SetBooleanFor(const CFX_ByteString& key, bool bValue) {
+  SetFor(key, new CPDF_Boolean(bValue));
+}
+
+void CPDF_Dictionary::SetRectFor(const CFX_ByteString& key,
+                                 const CFX_FloatRect& rect) {
+  CPDF_Array* pArray = new CPDF_Array;
+  pArray->AddNumber(rect.left);
+  pArray->AddNumber(rect.bottom);
+  pArray->AddNumber(rect.right);
+  pArray->AddNumber(rect.top);
+  SetFor(key, pArray);
+}
+
+void CPDF_Dictionary::SetMatrixFor(const CFX_ByteString& key,
+                                   const CFX_Matrix& matrix) {
+  CPDF_Array* pArray = new CPDF_Array;
+  pArray->AddNumber(matrix.a);
+  pArray->AddNumber(matrix.b);
+  pArray->AddNumber(matrix.c);
+  pArray->AddNumber(matrix.d);
+  pArray->AddNumber(matrix.e);
+  pArray->AddNumber(matrix.f);
+  SetFor(key, pArray);
+}
+
+CFX_ByteString CPDF_Dictionary::MaybeIntern(const CFX_ByteString& str) {
+  return m_pPool ? m_pPool->Intern(str) : str;
+}
diff --git a/core/fpdfapi/parser/cpdf_dictionary.h b/core/fpdfapi/parser/cpdf_dictionary.h
new file mode 100644
index 0000000000..2da4409b71
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_dictionary.h
@@ -0,0 +1,98 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#ifndef CORE_FPDFAPI_PARSER_CPDF_DICTIONARY_H_
+#define CORE_FPDFAPI_PARSER_CPDF_DICTIONARY_H_
+
+#include <map>
+#include <set>
+
+#include "core/fpdfapi/parser/cpdf_object.h"
+#include "core/fxcrt/cfx_string_pool_template.h"
+#include "core/fxcrt/cfx_weak_ptr.h"
+#include "core/fxcrt/fx_coordinates.h"
+#include "core/fxcrt/fx_string.h"
+
+class CPDF_IndirectObjectHolder;
+
+class CPDF_Dictionary : public CPDF_Object {
+ public:
+  using iterator = std::map<CFX_ByteString, CPDF_Object*>::iterator;
+  using const_iterator = std::map<CFX_ByteString, CPDF_Object*>::const_iterator;
+
+  CPDF_Dictionary();
+  explicit CPDF_Dictionary(const CFX_WeakPtr<CFX_ByteStringPool>& pPool);
+
+  // CPDF_Object.
+  Type GetType() const override;
+  CPDF_Object* Clone() const override;
+  CPDF_Dictionary* GetDict() const override;
+  bool IsDictionary() const override;
+  CPDF_Dictionary* AsDictionary() override;
+  const CPDF_Dictionary* AsDictionary() const override;
+
+  size_t GetCount() const { return m_Map.size(); }
+  CPDF_Object* GetObjectFor(const CFX_ByteString& key) const;
+  CPDF_Object* GetDirectObjectFor(const CFX_ByteString& key) const;
+  CFX_ByteString GetStringFor(const CFX_ByteString& key) const;
+  CFX_ByteString GetStringFor(const CFX_ByteString& key,
+                              const CFX_ByteString& default_str) const;
+  CFX_WideString GetUnicodeTextFor(const CFX_ByteString& key) const;
+  int GetIntegerFor(const CFX_ByteString& key) const;
+  int GetIntegerFor(const CFX_ByteString& key, int default_int) const;
+  bool GetBooleanFor(const CFX_ByteString& key, bool bDefault = false) const;
+  FX_FLOAT GetNumberFor(const CFX_ByteString& key) const;
+  CPDF_Dictionary* GetDictFor(const CFX_ByteString& key) const;
+  CPDF_Stream* GetStreamFor(const CFX_ByteString& key) const;
+  CPDF_Array* GetArrayFor(const CFX_ByteString& key) const;
+  CFX_FloatRect GetRectFor(const CFX_ByteString& key) const;
+  CFX_Matrix GetMatrixFor(const CFX_ByteString& key) const;
+  FX_FLOAT GetFloatFor(const CFX_ByteString& key) const {
+    return GetNumberFor(key);
+  }
+
+  FX_BOOL KeyExist(const CFX_ByteString& key) const;
+  bool IsSignatureDict() const;
+
+  // Set* functions invalidate iterators for the element with the key |key|.
+  void SetFor(const CFX_ByteString& key, CPDF_Object* pObj);
+  void SetNameFor(const CFX_ByteString& key, const CFX_ByteString& name);
+  void SetStringFor(const CFX_ByteString& key, const CFX_ByteString& str);
+  void SetIntegerFor(const CFX_ByteString& key, int i);
+  void SetNumberFor(const CFX_ByteString& key, FX_FLOAT f);
+  void SetReferenceFor(const CFX_ByteString& key,
+                       CPDF_IndirectObjectHolder* pDoc,
+                       uint32_t objnum);
+  void SetRectFor(const CFX_ByteString& key, const CFX_FloatRect& rect);
+  void SetMatrixFor(const CFX_ByteString& key, const CFX_Matrix& matrix);
+  void SetBooleanFor(const CFX_ByteString& key, bool bValue);
+
+  // Invalidates iterators for the element with the key |key|.
+  void RemoveFor(const CFX_ByteString& key);
+
+  // Invalidates iterators for the element with the key |oldkey|.
+  void ReplaceKey(const CFX_ByteString& oldkey, const CFX_ByteString& newkey);
+
+  iterator begin() { return m_Map.begin(); }
+  iterator end() { return m_Map.end(); }
+  const_iterator begin() const { return m_Map.begin(); }
+  const_iterator end() const { return m_Map.end(); }
+
+  CFX_WeakPtr<CFX_ByteStringPool> GetByteStringPool() const { return m_pPool; }
+
+ protected:
+  ~CPDF_Dictionary() override;
+
+  CFX_ByteString MaybeIntern(const CFX_ByteString& str);
+  CPDF_Object* CloneNonCyclic(
+      bool bDirect,
+      std::set<const CPDF_Object*>* visited) const override;
+
+  CFX_WeakPtr<CFX_ByteStringPool> m_pPool;
+  std::map<CFX_ByteString, CPDF_Object*> m_Map;
+};
+
+#endif  // CORE_FPDFAPI_PARSER_CPDF_DICTIONARY_H_
diff --git a/core/fpdfapi/parser/cpdf_document.cpp b/core/fpdfapi/parser/cpdf_document.cpp
new file mode 100644
index 0000000000..bf6439cc8c
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_document.cpp
@@ -0,0 +1,1020 @@
+// Copyright 2014 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#include "core/fpdfapi/parser/cpdf_document.h"
+
+#include <memory>
+#include <set>
+#include <vector>
+
+#include "core/fpdfapi/cpdf_modulemgr.h"
+#include "core/fpdfapi/font/cpdf_fontencoding.h"
+#include "core/fpdfapi/fpdf_render/render_int.h"
+#include "core/fpdfapi/page/cpdf_pagemodule.h"
+#include "core/fpdfapi/page/pageint.h"
+#include "core/fpdfapi/parser/cpdf_array.h"
+#include "core/fpdfapi/parser/cpdf_dictionary.h"
+#include "core/fpdfapi/parser/cpdf_parser.h"
+#include "core/fpdfapi/parser/cpdf_reference.h"
+#include "core/fpdfapi/parser/cpdf_stream.h"
+#include "core/fxcodec/JBig2_DocumentContext.h"
+#include "core/fxge/cfx_unicodeencoding.h"
+#include "core/fxge/fx_font.h"
+#include "third_party/base/ptr_util.h"
+#include "third_party/base/stl_util.h"
+
+namespace {
+
+const int FX_MAX_PAGE_LEVEL = 1024;
+
+const uint16_t g_FX_CP874Unicodes[128] = {
+    0x20AC, 0x0000, 0x0000, 0x0000, 0x0000, 0x2026, 0x0000, 0x0000, 0x0000,
+    0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x2018,
+    0x2019, 0x201C, 0x201D, 0x2022, 0x2013, 0x2014, 0x0000, 0x0000, 0x0000,
+    0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x00A0, 0x0E01, 0x0E02, 0x0E03,
+    0x0E04, 0x0E05, 0x0E06, 0x0E07, 0x0E08, 0x0E09, 0x0E0A, 0x0E0B, 0x0E0C,
+    0x0E0D, 0x0E0E, 0x0E0F, 0x0E10, 0x0E11, 0x0E12, 0x0E13, 0x0E14, 0x0E15,
+    0x0E16, 0x0E17, 0x0E18, 0x0E19, 0x0E1A, 0x0E1B, 0x0E1C, 0x0E1D, 0x0E1E,
+    0x0E1F, 0x0E20, 0x0E21, 0x0E22, 0x0E23, 0x0E24, 0x0E25, 0x0E26, 0x0E27,
+    0x0E28, 0x0E29, 0x0E2A, 0x0E2B, 0x0E2C, 0x0E2D, 0x0E2E, 0x0E2F, 0x0E30,
+    0x0E31, 0x0E32, 0x0E33, 0x0E34, 0x0E35, 0x0E36, 0x0E37, 0x0E38, 0x0E39,
+    0x0E3A, 0x0000, 0x0000, 0x0000, 0x0000, 0x0E3F, 0x0E40, 0x0E41, 0x0E42,
+    0x0E43, 0x0E44, 0x0E45, 0x0E46, 0x0E47, 0x0E48, 0x0E49, 0x0E4A, 0x0E4B,
+    0x0E4C, 0x0E4D, 0x0E4E, 0x0E4F, 0x0E50, 0x0E51, 0x0E52, 0x0E53, 0x0E54,
+    0x0E55, 0x0E56, 0x0E57, 0x0E58, 0x0E59, 0x0E5A, 0x0E5B, 0x0000, 0x0000,
+    0x0000, 0x0000,
+};
+const uint16_t g_FX_CP1250Unicodes[128] = {
+    0x20AC, 0x0000, 0x201A, 0x0000, 0x201E, 0x2026, 0x2020, 0x2021, 0x0000,
+    0x2030, 0x0160, 0x2039, 0x015A, 0x0164, 0x017D, 0x0179, 0x0000, 0x2018,
+    0x2019, 0x201C, 0x201D, 0x2022, 0x2013, 0x2014, 0x0000, 0x2122, 0x0161,
+    0x203A, 0x015B, 0x0165, 0x017E, 0x017A, 0x00A0, 0x02C7, 0x02D8, 0x0141,
+    0x00A4, 0x0104, 0x00A6, 0x00A7, 0x00A8, 0x00A9, 0x015E, 0x00AB, 0x00AC,
+    0x00AD, 0x00AE, 0x017B, 0x00B0, 0x00B1, 0x02DB, 0x0142, 0x00B4, 0x00B5,
+    0x00B6, 0x00B7, 0x00B8, 0x0105, 0x015F, 0x00BB, 0x013D, 0x02DD, 0x013E,
+    0x017C, 0x0154, 0x00C1, 0x00C2, 0x0102, 0x00C4, 0x0139, 0x0106, 0x00C7,
+    0x010C, 0x00C9, 0x0118, 0x00CB, 0x011A, 0x00CD, 0x00CE, 0x010E, 0x0110,
+    0x0143, 0x0147, 0x00D3, 0x00D4, 0x0150, 0x00D6, 0x00D7, 0x0158, 0x016E,
+    0x00DA, 0x0170, 0x00DC, 0x00DD, 0x0162, 0x00DF, 0x0155, 0x00E1, 0x00E2,
+    0x0103, 0x00E4, 0x013A, 0x0107, 0x00E7, 0x010D, 0x00E9, 0x0119, 0x00EB,
+    0x011B, 0x00ED, 0x00EE, 0x010F, 0x0111, 0x0144, 0x0148, 0x00F3, 0x00F4,
+    0x0151, 0x00F6, 0x00F7, 0x0159, 0x016F, 0x00FA, 0x0171, 0x00FC, 0x00FD,
+    0x0163, 0x02D9,
+};
+const uint16_t g_FX_CP1251Unicodes[128] = {
+    0x0402, 0x0403, 0x201A, 0x0453, 0x201E, 0x2026, 0x2020, 0x2021, 0x20AC,
+    0x2030, 0x0409, 0x2039, 0x040A, 0x040C, 0x040B, 0x040F, 0x0452, 0x2018,
+    0x2019, 0x201C, 0x201D, 0x2022, 0x2013, 0x2014, 0x0000, 0x2122, 0x0459,
+    0x203A, 0x045A, 0x045C, 0x045B, 0x045F, 0x00A0, 0x040E, 0x045E, 0x0408,
+    0x00A4, 0x0490, 0x00A6, 0x00A7, 0x0401, 0x00A9, 0x0404, 0x00AB, 0x00AC,
+    0x00AD, 0x00AE, 0x0407, 0x00B0, 0x00B1, 0x0406, 0x0456, 0x0491, 0x00B5,
+    0x00B6, 0x00B7, 0x0451, 0x2116, 0x0454, 0x00BB, 0x0458, 0x0405, 0x0455,
+    0x0457, 0x0410, 0x0411, 0x0412, 0x0413, 0x0414, 0x0415, 0x0416, 0x0417,
+    0x0418, 0x0419, 0x041A, 0x041B, 0x041C, 0x041D, 0x041E, 0x041F, 0x0420,
+    0x0421, 0x0422, 0x0423, 0x0424, 0x0425, 0x0426, 0x0427, 0x0428, 0x0429,
+    0x042A, 0x042B, 0x042C, 0x042D, 0x042E, 0x042F, 0x0430, 0x0431, 0x0432,
+    0x0433, 0x0434, 0x0435, 0x0436, 0x0437, 0x0438, 0x0439, 0x043A, 0x043B,
+    0x043C, 0x043D, 0x043E, 0x043F, 0x0440, 0x0441, 0x0442, 0x0443, 0x0444,
+    0x0445, 0x0446, 0x0447, 0x0448, 0x0449, 0x044A, 0x044B, 0x044C, 0x044D,
+    0x044E, 0x044F,
+};
+const uint16_t g_FX_CP1253Unicodes[128] = {
+    0x20AC, 0x0000, 0x201A, 0x0192, 0x201E, 0x2026, 0x2020, 0x2021, 0x0000,
+    0x2030, 0x0000, 0x2039, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x2018,
+    0x2019, 0x201C, 0x201D, 0x2022, 0x2013, 0x2014, 0x0000, 0x2122, 0x0000,
+    0x203A, 0x0000, 0x0000, 0x0000, 0x0000, 0x00A0, 0x0385, 0x0386, 0x00A3,
+    0x00A4, 0x00A5, 0x00A6, 0x00A7, 0x00A8, 0x00A9, 0x0000, 0x00AB, 0x00AC,
+    0x00AD, 0x00AE, 0x2015, 0x00B0, 0x00B1, 0x00B2, 0x00B3, 0x0384, 0x00B5,
+    0x00B6, 0x00B7, 0x0388, 0x0389, 0x038A, 0x00BB, 0x038C, 0x00BD, 0x038E,
+    0x038F, 0x0390, 0x0391, 0x0392, 0x0393, 0x0394, 0x0395, 0x0396, 0x0397,
+    0x0398, 0x0399, 0x039A, 0x039B, 0x039C, 0x039D, 0x039E, 0x039F, 0x03A0,
+    0x03A1, 0x0000, 0x03A3, 0x03A4, 0x03A5, 0x03A6, 0x03A7, 0x03A8, 0x03A9,
+    0x03AA, 0x03AB, 0x03AC, 0x03AD, 0x03AE, 0x03AF, 0x03B0, 0x03B1, 0x03B2,
+    0x03B3, 0x03B4, 0x03B5, 0x03B6, 0x03B7, 0x03B8, 0x03B9, 0x03BA, 0x03BB,
+    0x03BC, 0x03BD, 0x03BE, 0x03BF, 0x03C0, 0x03C1, 0x03C2, 0x03C3, 0x03C4,
+    0x03C5, 0x03C6, 0x03C7, 0x03C8, 0x03C9, 0x03CA, 0x03CB, 0x03CC, 0x03CD,
+    0x03CE, 0x0000,
+};
+const uint16_t g_FX_CP1254Unicodes[128] = {
+    0x20AC, 0x0000, 0x201A, 0x0192, 0x201E, 0x2026, 0x2020, 0x2021, 0x02C6,
+    0x2030, 0x0160, 0x2039, 0x0152, 0x0000, 0x0000, 0x0000, 0x0000, 0x2018,
+    0x2019, 0x201C, 0x201D, 0x2022, 0x2013, 0x2014, 0x02DC, 0x2122, 0x0161,
+    0x203A, 0x0153, 0x0000, 0x0000, 0x0178, 0x00A0, 0x00A1, 0x00A2, 0x00A3,
+    0x00A4, 0x00A5, 0x00A6, 0x00A7, 0x00A8, 0x00A9, 0x00AA, 0x00AB, 0x00AC,
+    0x00AD, 0x00AE, 0x00AF, 0x00B0, 0x00B1, 0x00B2, 0x00B3, 0x00B4, 0x00B5,
+    0x00B6, 0x00B7, 0x00B8, 0x00B9, 0x00BA, 0x00BB, 0x00BC, 0x00BD, 0x00BE,
+    0x00BF, 0x00C0, 0x00C1, 0x00C2, 0x00C3, 0x00C4, 0x00C5, 0x00C6, 0x00C7,
+    0x00C8, 0x00C9, 0x00CA, 0x00CB, 0x00CC, 0x00CD, 0x00CE, 0x00CF, 0x011E,
+    0x00D1, 0x00D2, 0x00D3, 0x00D4, 0x00D5, 0x00D6, 0x00D7, 0x00D8, 0x00D9,
+    0x00DA, 0x00DB, 0x00DC, 0x0130, 0x015E, 0x00DF, 0x00E0, 0x00E1, 0x00E2,
+    0x00E3, 0x00E4, 0x00E5, 0x00E6, 0x00E7, 0x00E8, 0x00E9, 0x00EA, 0x00EB,
+    0x00EC, 0x00ED, 0x00EE, 0x00EF, 0x011F, 0x00F1, 0x00F2, 0x00F3, 0x00F4,
+    0x00F5, 0x00F6, 0x00F7, 0x00F8, 0x00F9, 0x00FA, 0x00FB, 0x00FC, 0x0131,
+    0x015F, 0x00FF,
+};
+const uint16_t g_FX_CP1255Unicodes[128] = {
+    0x20AC, 0x0000, 0x201A, 0x0192, 0x201E, 0x2026, 0x2020, 0x2021, 0x02C6,
+    0x2030, 0x0000, 0x2039, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x2018,
+    0x2019, 0x201C, 0x201D, 0x2022, 0x2013, 0x2014, 0x02DC, 0x2122, 0x0000,
+    0x203A, 0x0000, 0x0000, 0x0000, 0x0000, 0x00A0, 0x00A1, 0x00A2, 0x00A3,
+    0x20AA, 0x00A5, 0x00A6, 0x00A7, 0x00A8, 0x00A9, 0x00D7, 0x00AB, 0x00AC,
+    0x00AD, 0x00AE, 0x00AF, 0x00B0, 0x00B1, 0x00B2, 0x00B3, 0x00B4, 0x00B5,
+    0x00B6, 0x00B7, 0x00B8, 0x00B9, 0x00F7, 0x00BB, 0x00BC, 0x00BD, 0x00BE,
+    0x00BF, 0x05B0, 0x05B1, 0x05B2, 0x05B3, 0x05B4, 0x05B5, 0x05B6, 0x05B7,
+    0x05B8, 0x05B9, 0x0000, 0x05BB, 0x05BC, 0x05BD, 0x05BE, 0x05BF, 0x05C0,
+    0x05C1, 0x05C2, 0x05C3, 0x05F0, 0x05F1, 0x05F2, 0x05F3, 0x05F4, 0x0000,
+    0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x05D0, 0x05D1, 0x05D2,
+    0x05D3, 0x05D4, 0x05D5, 0x05D6, 0x05D7, 0x05D8, 0x05D9, 0x05DA, 0x05DB,
+    0x05DC, 0x05DD, 0x05DE, 0x05DF, 0x05E0, 0x05E1, 0x05E2, 0x05E3, 0x05E4,
+    0x05E5, 0x05E6, 0x05E7, 0x05E8, 0x05E9, 0x05EA, 0x0000, 0x0000, 0x200E,
+    0x200F, 0x0000,
+};
+const uint16_t g_FX_CP1256Unicodes[128] = {
+    0x20AC, 0x067E, 0x201A, 0x0192, 0x201E, 0x2026, 0x2020, 0x2021, 0x02C6,
+    0x2030, 0x0679, 0x2039, 0x0152, 0x0686, 0x0698, 0x0688, 0x06AF, 0x2018,
+    0x2019, 0x201C, 0x201D, 0x2022, 0x2013, 0x2014, 0x06A9, 0x2122, 0x0691,
+    0x203A, 0x0153, 0x200C, 0x200D, 0x06BA, 0x00A0, 0x060C, 0x00A2, 0x00A3,
+    0x00A4, 0x00A5, 0x00A6, 0x00A7, 0x00A8, 0x00A9, 0x06BE, 0x00AB, 0x00AC,
+    0x00AD, 0x00AE, 0x00AF, 0x00B0, 0x00B1, 0x00B2, 0x00B3, 0x00B4, 0x00B5,
+    0x00B6, 0x00B7, 0x00B8, 0x00B9, 0x061B, 0x00BB, 0x00BC, 0x00BD, 0x00BE,
+    0x061F, 0x06C1, 0x0621, 0x0622, 0x0623, 0x0624, 0x0625, 0x0626, 0x0627,
+    0x0628, 0x0629, 0x062A, 0x062B, 0x062C, 0x062D, 0x062E, 0x062F, 0x0630,
+    0x0631, 0x0632, 0x0633, 0x0634, 0x0635, 0x0636, 0x00D7, 0x0637, 0x0638,
+    0x0639, 0x063A, 0x0640, 0x0641, 0x0642, 0x0643, 0x00E0, 0x0644, 0x00E2,
+    0x0645, 0x0646, 0x0647, 0x0648, 0x00E7, 0x00E8, 0x00E9, 0x00EA, 0x00EB,
+    0x0649, 0x064A, 0x00EE, 0x00EF, 0x064B, 0x064C, 0x064D, 0x064E, 0x00F4,
+    0x064F, 0x0650, 0x00F7, 0x0651, 0x00F9, 0x0652, 0x00FB, 0x00FC, 0x200E,
+    0x200F, 0x06D2,
+};
+const uint16_t g_FX_CP1257Unicodes[128] = {
+    0x20AC, 0x0000, 0x201A, 0x0000, 0x201E, 0x2026, 0x2020, 0x2021, 0x0000,
+    0x2030, 0x0000, 0x2039, 0x0000, 0x00A8, 0x02C7, 0x00B8, 0x0000, 0x2018,
+    0x2019, 0x201C, 0x201D, 0x2022, 0x2013, 0x2014, 0x0000, 0x2122, 0x0000,
+    0x203A, 0x0000, 0x00AF, 0x02DB, 0x0000, 0x00A0, 0x0000, 0x00A2, 0x00A3,
+    0x00A4, 0x0000, 0x00A6, 0x00A7, 0x00D8, 0x00A9, 0x0156, 0x00AB, 0x00AC,
+    0x00AD, 0x00AE, 0x00C6, 0x00B0, 0x00B1, 0x00B2, 0x00B3, 0x00B4, 0x00B5,
+    0x00B6, 0x00B7, 0x00F8, 0x00B9, 0x0157, 0x00BB, 0x00BC, 0x00BD, 0x00BE,
+    0x00E6, 0x0104, 0x012E, 0x0100, 0x0106, 0x00C4, 0x00C5, 0x0118, 0x0112,
+    0x010C, 0x00C9, 0x0179, 0x0116, 0x0122, 0x0136, 0x012A, 0x013B, 0x0160,
+    0x0143, 0x0145, 0x00D3, 0x014C, 0x00D5, 0x00D6, 0x00D7, 0x0172, 0x0141,
+    0x015A, 0x016A, 0x00DC, 0x017B, 0x017D, 0x00DF, 0x0105, 0x012F, 0x0101,
+    0x0107, 0x00E4, 0x00E5, 0x0119, 0x0113, 0x010D, 0x00E9, 0x017A, 0x0117,
+    0x0123, 0x0137, 0x012B, 0x013C, 0x0161, 0x0144, 0x0146, 0x00F3, 0x014D,
+    0x00F5, 0x00F6, 0x00F7, 0x0173, 0x0142, 0x015B, 0x016B, 0x00FC, 0x017C,
+    0x017E, 0x02D9,
+};
+
+struct FX_CharsetUnicodes {
+  uint8_t m_Charset;
+  const uint16_t* m_pUnicodes;
+};
+
+const FX_CharsetUnicodes g_FX_CharsetUnicodes[] = {
+    {FXFONT_THAI_CHARSET, g_FX_CP874Unicodes},
+    {FXFONT_EASTEUROPE_CHARSET, g_FX_CP1250Unicodes},
+    {FXFONT_RUSSIAN_CHARSET, g_FX_CP1251Unicodes},
+    {FXFONT_GREEK_CHARSET, g_FX_CP1253Unicodes},
+    {FXFONT_TURKISH_CHARSET, g_FX_CP1254Unicodes},
+    {FXFONT_HEBREW_CHARSET, g_FX_CP1255Unicodes},
+    {FXFONT_ARABIC_CHARSET, g_FX_CP1256Unicodes},
+    {FXFONT_BALTIC_CHARSET, g_FX_CP1257Unicodes},
+};
+
+void InsertWidthArrayImpl(int* widths, int size, CPDF_Array* pWidthArray) {
+  int i;
+  for (i = 1; i < size; i++) {
+    if (widths[i] != *widths)
+      break;
+  }
+  if (i == size) {
+    int first = pWidthArray->GetIntegerAt(pWidthArray->GetCount() - 1);
+    pWidthArray->AddInteger(first + size - 1);
+    pWidthArray->AddInteger(*widths);
+  } else {
+    CPDF_Array* pWidthArray1 = new CPDF_Array;
+    pWidthArray->Add(pWidthArray1);
+    for (i = 0; i < size; i++)
+      pWidthArray1->AddInteger(widths[i]);
+  }
+  FX_Free(widths);
+}
+
+#if _FXM_PLATFORM_ == _FXM_PLATFORM_WINDOWS_
+void InsertWidthArray(HDC hDC, int start, int end, CPDF_Array* pWidthArray) {
+  int size = end - start + 1;
+  int* widths = FX_Alloc(int, size);
+  GetCharWidth(hDC, start, end, widths);
+  InsertWidthArrayImpl(widths, size, pWidthArray);
+}
+
+CFX_ByteString FPDF_GetPSNameFromTT(HDC hDC) {
+  CFX_ByteString result;
+  DWORD size = ::GetFontData(hDC, 'eman', 0, nullptr, 0);
+  if (size != GDI_ERROR) {
+    LPBYTE buffer = FX_Alloc(BYTE, size);
+    ::GetFontData(hDC, 'eman', 0, buffer, size);
+    result = GetNameFromTT(buffer, size, 6);
+    FX_Free(buffer);
+  }
+  return result;
+}
+#endif  // _FXM_PLATFORM_ == _FXM_PLATFORM_WINDOWS_
+
+void InsertWidthArray1(CFX_Font* pFont,
+                       CFX_UnicodeEncoding* pEncoding,
+                       FX_WCHAR start,
+                       FX_WCHAR end,
+                       CPDF_Array* pWidthArray) {
+  int size = end - start + 1;
+  int* widths = FX_Alloc(int, size);
+  int i;
+  for (i = 0; i < size; i++) {
+    int glyph_index = pEncoding->GlyphFromCharCode(start + i);
+    widths[i] = pFont->GetGlyphWidth(glyph_index);
+  }
+  InsertWidthArrayImpl(widths, size, pWidthArray);
+}
+
+int InsertDeletePDFPage(CPDF_Document* pDoc,
+                        CPDF_Dictionary* pPages,
+                        int nPagesToGo,
+                        CPDF_Dictionary* pPage,
+                        FX_BOOL bInsert,
+                        std::set<CPDF_Dictionary*>* pVisited) {
+  CPDF_Array* pKidList = pPages->GetArrayFor("Kids");
+  if (!pKidList)
+    return -1;
+
+  for (size_t i = 0; i < pKidList->GetCount(); i++) {
+    CPDF_Dictionary* pKid = pKidList->GetDictAt(i);
+    if (pKid->GetStringFor("Type") == "Page") {
+      if (nPagesToGo == 0) {
+        if (bInsert) {
+          pKidList->InsertAt(i, new CPDF_Reference(pDoc, pPage->GetObjNum()));
+          pPage->SetReferenceFor("Parent", pDoc, pPages->GetObjNum());
+        } else {
+          pKidList->RemoveAt(i);
+        }
+        pPages->SetIntegerFor(
+            "Count", pPages->GetIntegerFor("Count") + (bInsert ? 1 : -1));
+        return 1;
+      }
+      nPagesToGo--;
+    } else {
+      int nPages = pKid->GetIntegerFor("Count");
+      if (nPagesToGo < nPages) {
+        if (pdfium::ContainsKey(*pVisited, pKid))
+          return -1;
+
+        pdfium::ScopedSetInsertion<CPDF_Dictionary*> insertion(pVisited, pKid);
+        if (InsertDeletePDFPage(pDoc, pKid, nPagesToGo, pPage, bInsert,
+                                pVisited) < 0) {
+          return -1;
+        }
+        pPages->SetIntegerFor(
+            "Count", pPages->GetIntegerFor("Count") + (bInsert ? 1 : -1));
+        return 1;
+      }
+      nPagesToGo -= nPages;
+    }
+  }
+  return 0;
+}
+
+int InsertNewPage(CPDF_Document* pDoc,
+                  int iPage,
+                  CPDF_Dictionary* pPageDict,
+                  CFX_ArrayTemplate<uint32_t>& pageList) {
+  CPDF_Dictionary* pRoot = pDoc->GetRoot();
+  CPDF_Dictionary* pPages = pRoot ? pRoot->GetDictFor("Pages") : nullptr;
+  if (!pPages)
+    return -1;
+
+  int nPages = pDoc->GetPageCount();
+  if (iPage < 0 || iPage > nPages)
+    return -1;
+
+  if (iPage == nPages) {
+    CPDF_Array* pPagesList = pPages->GetArrayFor("Kids");
+    if (!pPagesList) {
+      pPagesList = new CPDF_Array;
+      pPages->SetFor("Kids", pPagesList);
+    }
+    pPagesList->Add(new CPDF_Reference(pDoc, pPageDict->GetObjNum()));
+    pPages->SetIntegerFor("Count", nPages + 1);
+    pPageDict->SetReferenceFor("Parent", pDoc, pPages->GetObjNum());
+  } else {
+    std::set<CPDF_Dictionary*> stack = {pPages};
+    if (InsertDeletePDFPage(pDoc, pPages, iPage, pPageDict, TRUE, &stack) < 0)
+      return -1;
+  }
+  pageList.InsertAt(iPage, pPageDict->GetObjNum());
+  return iPage;
+}
+
+int CountPages(CPDF_Dictionary* pPages,
+               std::set<CPDF_Dictionary*>* visited_pages) {
+  int count = pPages->GetIntegerFor("Count");
+  if (count > 0 && count < FPDF_PAGE_MAX_NUM)
+    return count;
+  CPDF_Array* pKidList = pPages->GetArrayFor("Kids");
+  if (!pKidList)
+    return 0;
+  count = 0;
+  for (size_t i = 0; i < pKidList->GetCount(); i++) {
+    CPDF_Dictionary* pKid = pKidList->GetDictAt(i);
+    if (!pKid || pdfium::ContainsKey(*visited_pages, pKid))
+      continue;
+    if (pKid->KeyExist("Kids")) {
+      // Use |visited_pages| to help detect circular references of pages.
+      pdfium::ScopedSetInsertion<CPDF_Dictionary*> local_add(visited_pages,
+                                                             pKid);
+      count += CountPages(pKid, visited_pages);
+    } else {
+      // This page is a leaf node.
+      count++;
+    }
+  }
+  pPages->SetIntegerFor("Count", count);
+  return count;
+}
+
+int CalculateFlags(bool bold,
+                   bool italic,
+                   bool fixedPitch,
+                   bool serif,
+                   bool script,
+                   bool symbolic) {
+  int flags = 0;
+  if (bold)
+    flags |= PDFFONT_FORCEBOLD;
+  if (italic)
+    flags |= PDFFONT_ITALIC;
+  if (fixedPitch)
+    flags |= PDFFONT_FIXEDPITCH;
+  if (serif)
+    flags |= PDFFONT_SERIF;
+  if (script)
+    flags |= PDFFONT_SCRIPT;
+  if (symbolic)
+    flags |= PDFFONT_SYMBOLIC;
+  else
+    flags |= PDFFONT_NONSYMBOLIC;
+  return flags;
+}
+
+void ProcessNonbCJK(CPDF_Dictionary* pBaseDict,
+                    bool bold,
+                    bool italic,
+                    CFX_ByteString basefont,
+                    CPDF_Array* pWidths) {
+  if (bold && italic)
+    basefont += ",BoldItalic";
+  else if (bold)
+    basefont += ",Bold";
+  else if (italic)
+    basefont += ",Italic";
+  pBaseDict->SetNameFor("Subtype", "TrueType");
+  pBaseDict->SetNameFor("BaseFont", basefont);
+  pBaseDict->SetNumberFor("FirstChar", 32);
+  pBaseDict->SetNumberFor("LastChar", 255);
+  pBaseDict->SetFor("Widths", pWidths);
+}
+
+CPDF_Dictionary* CalculateFontDesc(CPDF_Document* pDoc,
+                                   CFX_ByteString basefont,
+                                   int flags,
+                                   int italicangle,
+                                   int ascend,
+                                   int descend,
+                                   CPDF_Array* bbox,
+                                   int32_t stemV) {
+  CPDF_Dictionary* pFontDesc = new CPDF_Dictionary(pDoc->GetByteStringPool());
+  pFontDesc->SetNameFor("Type", "FontDescriptor");
+  pFontDesc->SetNameFor("FontName", basefont);
+  pFontDesc->SetIntegerFor("Flags", flags);
+  pFontDesc->SetFor("FontBBox", bbox);
+  pFontDesc->SetIntegerFor("ItalicAngle", italicangle);
+  pFontDesc->SetIntegerFor("Ascent", ascend);
+  pFontDesc->SetIntegerFor("Descent", descend);
+  pFontDesc->SetIntegerFor("StemV", stemV);
+  return pFontDesc;
+}
+
+}  // namespace
+
+CPDF_Document::CPDF_Document(std::unique_ptr<CPDF_Parser> pParser)
+    : CPDF_IndirectObjectHolder(),
+      m_pParser(std::move(pParser)),
+      m_pRootDict(nullptr),
+      m_pInfoDict(nullptr),
+      m_bLinearized(false),
+      m_iFirstPageNo(0),
+      m_dwFirstPageObjNum(0),
+      m_pDocPage(new CPDF_DocPageData(this)),
+      m_pDocRender(new CPDF_DocRenderData(this)),
+      m_pByteStringPool(pdfium::MakeUnique<CFX_ByteStringPool>()) {
+  if (pParser)
+    SetLastObjNum(m_pParser->GetLastObjNum());
+}
+
+CPDF_Document::~CPDF_Document() {
+  delete m_pDocPage;
+  CPDF_ModuleMgr::Get()->GetPageModule()->ClearStockFont(this);
+  m_pByteStringPool.DeleteObject();  // Make weak.
+}
+
+CPDF_Object* CPDF_Document::ParseIndirectObject(uint32_t objnum) {
+  return m_pParser ? m_pParser->ParseIndirectObject(this, objnum) : nullptr;
+}
+
+void CPDF_Document::LoadDocInternal() {
+  SetLastObjNum(m_pParser->GetLastObjNum());
+
+  CPDF_Object* pRootObj = GetOrParseIndirectObject(m_pParser->GetRootObjNum());
+  if (!pRootObj)
+    return;
+
+  m_pRootDict = pRootObj->GetDict();
+  if (!m_pRootDict)
+    return;
+
+  CPDF_Object* pInfoObj = GetOrParseIndirectObject(m_pParser->GetInfoObjNum());
+  if (pInfoObj)
+    m_pInfoDict = pInfoObj->GetDict();
+}
+
+void CPDF_Document::LoadDoc() {
+  LoadDocInternal();
+  m_PageList.SetSize(RetrievePageCount());
+}
+
+void CPDF_Document::LoadLinearizedDoc(CPDF_Dictionary* pLinearizationParams) {
+  m_bLinearized = true;
+  LoadDocInternal();
+
+  uint32_t dwPageCount = 0;
+  CPDF_Object* pCount = pLinearizationParams->GetObjectFor("N");
+  if (ToNumber(pCount))
+    dwPageCount = pCount->GetInteger();
+  m_PageList.SetSize(dwPageCount);
+
+  CPDF_Object* pNo = pLinearizationParams->GetObjectFor("P");
+  if (ToNumber(pNo))
+    m_iFirstPageNo = pNo->GetInteger();
+
+  CPDF_Object* pObjNum = pLinearizationParams->GetObjectFor("O");
+  if (ToNumber(pObjNum))
+    m_dwFirstPageObjNum = pObjNum->GetInteger();
+}
+
+void CPDF_Document::LoadPages() {
+  m_PageList.SetSize(RetrievePageCount());
+}
+
+CPDF_Dictionary* CPDF_Document::FindPDFPage(CPDF_Dictionary* pPages,
+                                            int iPage,
+                                            int nPagesToGo,
+                                            int level) {
+  CPDF_Array* pKidList = pPages->GetArrayFor("Kids");
+  if (!pKidList)
+    return nPagesToGo == 0 ? pPages : nullptr;
+
+  if (level >= FX_MAX_PAGE_LEVEL)
+    return nullptr;
+
+  for (size_t i = 0; i < pKidList->GetCount(); i++) {
+    CPDF_Dictionary* pKid = pKidList->GetDictAt(i);
+    if (!pKid) {
+      nPagesToGo--;
+      continue;
+    }
+    if (pKid == pPages)
+      continue;
+    if (!pKid->KeyExist("Kids")) {
+      if (nPagesToGo == 0)
+        return pKid;
+
+      m_PageList.SetAt(iPage - nPagesToGo, pKid->GetObjNum());
+      nPagesToGo--;
+    } else {
+      int nPages = pKid->GetIntegerFor("Count");
+      if (nPagesToGo < nPages)
+        return FindPDFPage(pKid, iPage, nPagesToGo, level + 1);
+
+      nPagesToGo -= nPages;
+    }
+  }
+  return nullptr;
+}
+
+CPDF_Dictionary* CPDF_Document::GetPagesDict() const {
+  CPDF_Dictionary* pRoot = GetRoot();
+  return pRoot ? pRoot->GetDictFor("Pages") : nullptr;
+}
+
+bool CPDF_Document::IsPageLoaded(int iPage) const {
+  return !!m_PageList.GetAt(iPage);
+}
+
+CPDF_Dictionary* CPDF_Document::GetPage(int iPage) {
+  if (iPage < 0 || iPage >= m_PageList.GetSize())
+    return nullptr;
+
+  if (m_bLinearized && (iPage == m_iFirstPageNo)) {
+    if (CPDF_Dictionary* pDict =
+            ToDictionary(GetOrParseIndirectObject(m_dwFirstPageObjNum))) {
+      return pDict;
+    }
+  }
+
+  int objnum = m_PageList.GetAt(iPage);
+  if (objnum) {
+    if (CPDF_Dictionary* pDict = ToDictionary(GetOrParseIndirectObject(objnum)))
+      return pDict;
+  }
+
+  CPDF_Dictionary* pPages = GetPagesDict();
+  if (!pPages)
+    return nullptr;
+
+  CPDF_Dictionary* pPage = FindPDFPage(pPages, iPage, iPage, 0);
+  if (!pPage)
+    return nullptr;
+
+  m_PageList.SetAt(iPage, pPage->GetObjNum());
+  return pPage;
+}
+
+void CPDF_Document::SetPageObjNum(int iPage, uint32_t objNum) {
+  m_PageList.SetAt(iPage, objNum);
+}
+
+int CPDF_Document::FindPageIndex(CPDF_Dictionary* pNode,
+                                 uint32_t& skip_count,
+                                 uint32_t objnum,
+                                 int& index,
+                                 int level) {
+  if (!pNode->KeyExist("Kids")) {
+    if (objnum == pNode->GetObjNum())
+      return index;
+
+    if (skip_count)
+      skip_count--;
+
+    index++;
+    return -1;
+  }
+
+  CPDF_Array* pKidList = pNode->GetArrayFor("Kids");
+  if (!pKidList)
+    return -1;
+
+  if (level >= FX_MAX_PAGE_LEVEL)
+    return -1;
+
+  size_t count = pNode->GetIntegerFor("Count");
+  if (count <= skip_count) {
+    skip_count -= count;
+    index += count;
+    return -1;
+  }
+
+  if (count && count == pKidList->GetCount()) {
+    for (size_t i = 0; i < count; i++) {
+      if (CPDF_Reference* pKid = ToReference(pKidList->GetObjectAt(i))) {
+        if (pKid->GetRefObjNum() == objnum) {
+          m_PageList.SetAt(index + i, objnum);
+          return static_cast<int>(index + i);
+        }
+      }
+    }
+  }
+
+  for (size_t i = 0; i < pKidList->GetCount(); i++) {
+    CPDF_Dictionary* pKid = pKidList->GetDictAt(i);
+    if (!pKid || pKid == pNode)
+      continue;
+
+    int found_index = FindPageIndex(pKid, skip_count, objnum, index, level + 1);
+    if (found_index >= 0)
+      return found_index;
+  }
+  return -1;
+}
+
+int CPDF_Document::GetPageIndex(uint32_t objnum) {
+  uint32_t nPages = m_PageList.GetSize();
+  uint32_t skip_count = 0;
+  bool bSkipped = false;
+  for (uint32_t i = 0; i < nPages; i++) {
+    uint32_t objnum1 = m_PageList.GetAt(i);
+    if (objnum1 == objnum)
+      return i;
+
+    if (!bSkipped && objnum1 == 0) {
+      skip_count = i;
+      bSkipped = true;
+    }
+  }
+  CPDF_Dictionary* pPages = GetPagesDict();
+  if (!pPages)
+    return -1;
+
+  int index = 0;
+  return FindPageIndex(pPages, skip_count, objnum, index);
+}
+
+int CPDF_Document::GetPageCount() const {
+  return m_PageList.GetSize();
+}
+
+int CPDF_Document::RetrievePageCount() const {
+  CPDF_Dictionary* pPages = GetPagesDict();
+  if (!pPages)
+    return 0;
+
+  if (!pPages->KeyExist("Kids"))
+    return 1;
+
+  std::set<CPDF_Dictionary*> visited_pages;
+  visited_pages.insert(pPages);
+  return CountPages(pPages, &visited_pages);
+}
+
+uint32_t CPDF_Document::GetUserPermissions() const {
+  // https://bugs.chromium.org/p/pdfium/issues/detail?id=499
+  if (!m_pParser) {
+#ifndef PDF_ENABLE_XFA
+    return 0;
+#else  // PDF_ENABLE_XFA
+    return 0xFFFFFFFF;
+#endif
+  }
+  return m_pParser->GetPermissions();
+}
+
+CPDF_Font* CPDF_Document::LoadFont(CPDF_Dictionary* pFontDict) {
+  ASSERT(pFontDict);
+  return m_pDocPage->GetFont(pFontDict, FALSE);
+}
+
+CPDF_StreamAcc* CPDF_Document::LoadFontFile(CPDF_Stream* pStream) {
+  return m_pDocPage->GetFontFileStreamAcc(pStream);
+}
+
+CPDF_ColorSpace* CPDF_Document::LoadColorSpace(CPDF_Object* pCSObj,
+                                               CPDF_Dictionary* pResources) {
+  return m_pDocPage->GetColorSpace(pCSObj, pResources);
+}
+
+CPDF_Pattern* CPDF_Document::LoadPattern(CPDF_Object* pPatternObj,
+                                         FX_BOOL bShading,
+                                         const CFX_Matrix& matrix) {
+  return m_pDocPage->GetPattern(pPatternObj, bShading, matrix);
+}
+
+CPDF_IccProfile* CPDF_Document::LoadIccProfile(CPDF_Stream* pStream) {
+  return m_pDocPage->GetIccProfile(pStream);
+}
+
+CPDF_Image* CPDF_Document::LoadImageF(CPDF_Object* pObj) {
+  if (!pObj)
+    return nullptr;
+
+  ASSERT(pObj->GetObjNum());
+  return m_pDocPage->GetImage(pObj);
+}
+
+void CPDF_Document::CreateNewDoc() {
+  ASSERT(!m_pRootDict && !m_pInfoDict);
+  m_pRootDict = new CPDF_Dictionary(m_pByteStringPool);
+  m_pRootDict->SetNameFor("Type", "Catalog");
+  AddIndirectObject(m_pRootDict);
+
+  CPDF_Dictionary* pPages = new CPDF_Dictionary(m_pByteStringPool);
+  pPages->SetNameFor("Type", "Pages");
+  pPages->SetNumberFor("Count", 0);
+  pPages->SetFor("Kids", new CPDF_Array);
+  m_pRootDict->SetReferenceFor("Pages", this, AddIndirectObject(pPages));
+  m_pInfoDict = new CPDF_Dictionary(m_pByteStringPool);
+  AddIndirectObject(m_pInfoDict);
+}
+
+CPDF_Dictionary* CPDF_Document::CreateNewPage(int iPage) {
+  CPDF_Dictionary* pDict = new CPDF_Dictionary(m_pByteStringPool);
+  pDict->SetNameFor("Type", "Page");
+  uint32_t dwObjNum = AddIndirectObject(pDict);
+  if (InsertNewPage(this, iPage, pDict, m_PageList) < 0) {
+    ReleaseIndirectObject(dwObjNum);
+    return nullptr;
+  }
+  return pDict;
+}
+
+void CPDF_Document::DeletePage(int iPage) {
+  CPDF_Dictionary* pPages = GetPagesDict();
+  if (!pPages)
+    return;
+
+  int nPages = pPages->GetIntegerFor("Count");
+  if (iPage < 0 || iPage >= nPages)
+    return;
+
+  std::set<CPDF_Dictionary*> stack = {pPages};
+  if (InsertDeletePDFPage(this, pPages, iPage, nullptr, FALSE, &stack) < 0)
+    return;
+
+  m_PageList.RemoveAt(iPage);
+}
+
+CPDF_Font* CPDF_Document::AddStandardFont(const FX_CHAR* font,
+                                          CPDF_FontEncoding* pEncoding) {
+  CFX_ByteString name(font);
+  if (PDF_GetStandardFontName(&name) < 0)
+    return nullptr;
+  return GetPageData()->GetStandardFont(name, pEncoding);
+}
+
+size_t CPDF_Document::CalculateEncodingDict(int charset,
+                                            CPDF_Dictionary* pBaseDict) {
+  size_t i;
+  for (i = 0; i < FX_ArraySize(g_FX_CharsetUnicodes); ++i) {
+    if (g_FX_CharsetUnicodes[i].m_Charset == charset)
+      break;
+  }
+  if (i == FX_ArraySize(g_FX_CharsetUnicodes))
+    return i;
+  CPDF_Dictionary* pEncodingDict = new CPDF_Dictionary(m_pByteStringPool);
+  pEncodingDict->SetNameFor("BaseEncoding", "WinAnsiEncoding");
+  CPDF_Array* pArray = new CPDF_Array;
+  pArray->AddInteger(128);
+  const uint16_t* pUnicodes = g_FX_CharsetUnicodes[i].m_pUnicodes;
+  for (int j = 0; j < 128; j++) {
+    CFX_ByteString name = PDF_AdobeNameFromUnicode(pUnicodes[j]);
+    pArray->AddName(name.IsEmpty() ? ".notdef" : name);
+  }
+  pEncodingDict->SetFor("Differences", pArray);
+  pBaseDict->SetReferenceFor("Encoding", this,
+                             AddIndirectObject(pEncodingDict));
+
+  return i;
+}
+
+CPDF_Dictionary* CPDF_Document::ProcessbCJK(
+    CPDF_Dictionary* pBaseDict,
+    int charset,
+    FX_BOOL bVert,
+    CFX_ByteString basefont,
+    std::function<void(FX_WCHAR, FX_WCHAR, CPDF_Array*)> Insert) {
+  CPDF_Dictionary* pFontDict = new CPDF_Dictionary(m_pByteStringPool);
+  CFX_ByteString cmap;
+  CFX_ByteString ordering;
+  int supplement = 0;
+  CPDF_Array* pWidthArray = new CPDF_Array;
+  switch (charset) {
+    case FXFONT_CHINESEBIG5_CHARSET:
+      cmap = bVert ? "ETenms-B5-V" : "ETenms-B5-H";
+      ordering = "CNS1";
+      supplement = 4;
+      pWidthArray->AddInteger(1);
+      Insert(0x20, 0x7e, pWidthArray);
+      break;
+    case FXFONT_GB2312_CHARSET:
+      cmap = bVert ? "GBK-EUC-V" : "GBK-EUC-H";
+      ordering = "GB1";
+      supplement = 2;
+      pWidthArray->AddInteger(7716);
+      Insert(0x20, 0x20, pWidthArray);
+      pWidthArray->AddInteger(814);
+      Insert(0x21, 0x7e, pWidthArray);
+      break;
+    case FXFONT_HANGUL_CHARSET:
+      cmap = bVert ? "KSCms-UHC-V" : "KSCms-UHC-H";
+      ordering = "Korea1";
+      supplement = 2;
+      pWidthArray->AddInteger(1);
+      Insert(0x20, 0x7e, pWidthArray);
+      break;
+    case FXFONT_SHIFTJIS_CHARSET:
+      cmap = bVert ? "90ms-RKSJ-V" : "90ms-RKSJ-H";
+      ordering = "Japan1";
+      supplement = 5;
+      pWidthArray->AddInteger(231);
+      Insert(0x20, 0x7d, pWidthArray);
+      pWidthArray->AddInteger(326);
+      Insert(0xa0, 0xa0, pWidthArray);
+      pWidthArray->AddInteger(327);
+      Insert(0xa1, 0xdf, pWidthArray);
+      pWidthArray->AddInteger(631);
+      Insert(0x7e, 0x7e, pWidthArray);
+      break;
+  }
+  pBaseDict->SetNameFor("Subtype", "Type0");
+  pBaseDict->SetNameFor("BaseFont", basefont);
+  pBaseDict->SetNameFor("Encoding", cmap);
+  pFontDict->SetFor("W", pWidthArray);
+  pFontDict->SetNameFor("Type", "Font");
+  pFontDict->SetNameFor("Subtype", "CIDFontType2");
+  pFontDict->SetNameFor("BaseFont", basefont);
+  CPDF_Dictionary* pCIDSysInfo = new CPDF_Dictionary(m_pByteStringPool);
+  pCIDSysInfo->SetStringFor("Registry", "Adobe");
+  pCIDSysInfo->SetStringFor("Ordering", ordering);
+  pCIDSysInfo->SetIntegerFor("Supplement", supplement);
+  pFontDict->SetFor("CIDSystemInfo", pCIDSysInfo);
+  CPDF_Array* pArray = new CPDF_Array;
+  pBaseDict->SetFor("DescendantFonts", pArray);
+  pArray->AddReference(this, AddIndirectObject(pFontDict));
+  return pFontDict;
+}
+
+CPDF_Font* CPDF_Document::AddFont(CFX_Font* pFont, int charset, FX_BOOL bVert) {
+  if (!pFont)
+    return nullptr;
+
+  bool bCJK = charset == FXFONT_CHINESEBIG5_CHARSET ||
+              charset == FXFONT_GB2312_CHARSET ||
+              charset == FXFONT_HANGUL_CHARSET ||
+              charset == FXFONT_SHIFTJIS_CHARSET;
+  CFX_ByteString basefont = pFont->GetFamilyName();
+  basefont.Replace(" ", "");
+  int flags =
+      CalculateFlags(pFont->IsBold(), pFont->IsItalic(), pFont->IsFixedWidth(),
+                     false, false, charset == FXFONT_SYMBOL_CHARSET);
+
+  CPDF_Dictionary* pBaseDict = new CPDF_Dictionary(m_pByteStringPool);
+  pBaseDict->SetNameFor("Type", "Font");
+  std::unique_ptr<CFX_UnicodeEncoding> pEncoding(
+      new CFX_UnicodeEncoding(pFont));
+  CPDF_Dictionary* pFontDict = pBaseDict;
+  if (!bCJK) {
+    CPDF_Array* pWidths = new CPDF_Array;
+    for (int charcode = 32; charcode < 128; charcode++) {
+      int glyph_index = pEncoding->GlyphFromCharCode(charcode);
+      int char_width = pFont->GetGlyphWidth(glyph_index);
+      pWidths->AddInteger(char_width);
+    }
+    if (charset == FXFONT_ANSI_CHARSET || charset == FXFONT_DEFAULT_CHARSET ||
+        charset == FXFONT_SYMBOL_CHARSET) {
+      pBaseDict->SetNameFor("Encoding", "WinAnsiEncoding");
+      for (int charcode = 128; charcode <= 255; charcode++) {
+        int glyph_index = pEncoding->GlyphFromCharCode(charcode);
+        int char_width = pFont->GetGlyphWidth(glyph_index);
+        pWidths->AddInteger(char_width);
+      }
+    } else {
+      size_t i = CalculateEncodingDict(charset, pBaseDict);
+      if (i < FX_ArraySize(g_FX_CharsetUnicodes)) {
+        const uint16_t* pUnicodes = g_FX_CharsetUnicodes[i].m_pUnicodes;
+        for (int j = 0; j < 128; j++) {
+          int glyph_index = pEncoding->GlyphFromCharCode(pUnicodes[j]);
+          int char_width = pFont->GetGlyphWidth(glyph_index);
+          pWidths->AddInteger(char_width);
+        }
+      }
+    }
+    ProcessNonbCJK(pBaseDict, pFont->IsBold(), pFont->IsItalic(), basefont,
+                   pWidths);
+  } else {
+    pFontDict = ProcessbCJK(pBaseDict, charset, bVert, basefont,
+                            [pFont, &pEncoding](FX_WCHAR start, FX_WCHAR end,
+                                                CPDF_Array* widthArr) {
+                              InsertWidthArray1(pFont, pEncoding.get(), start,
+                                                end, widthArr);
+                            });
+  }
+  AddIndirectObject(pBaseDict);
+  int italicangle =
+      pFont->GetSubstFont() ? pFont->GetSubstFont()->m_ItalicAngle : 0;
+  FX_RECT bbox;
+  pFont->GetBBox(bbox);
+  CPDF_Array* pBBox = new CPDF_Array;
+  pBBox->AddInteger(bbox.left);
+  pBBox->AddInteger(bbox.bottom);
+  pBBox->AddInteger(bbox.right);
+  pBBox->AddInteger(bbox.top);
+  int32_t nStemV = 0;
+  if (pFont->GetSubstFont()) {
+    nStemV = pFont->GetSubstFont()->m_Weight / 5;
+  } else {
+    static const FX_CHAR stem_chars[] = {'i', 'I', '!', '1'};
+    const size_t count = FX_ArraySize(stem_chars);
+    uint32_t glyph = pEncoding->GlyphFromCharCode(stem_chars[0]);
+    nStemV = pFont->GetGlyphWidth(glyph);
+    for (size_t i = 1; i < count; i++) {
+      glyph = pEncoding->GlyphFromCharCode(stem_chars[i]);
+      int width = pFont->GetGlyphWidth(glyph);
+      if (width > 0 && width < nStemV)
+        nStemV = width;
+    }
+  }
+  CPDF_Dictionary* pFontDesc =
+      CalculateFontDesc(this, basefont, flags, italicangle, pFont->GetAscent(),
+                        pFont->GetDescent(), pBBox, nStemV);
+  pFontDict->SetReferenceFor("FontDescriptor", this,
+                             AddIndirectObject(pFontDesc));
+  return LoadFont(pBaseDict);
+}
+
+#if _FXM_PLATFORM_ == _FXM_PLATFORM_WINDOWS_
+CPDF_Font* CPDF_Document::AddWindowsFont(LOGFONTW* pLogFont,
+                                         FX_BOOL bVert,
+                                         FX_BOOL bTranslateName) {
+  LOGFONTA lfa;
+  FXSYS_memcpy(&lfa, pLogFont, (char*)lfa.lfFaceName - (char*)&lfa);
+  CFX_ByteString face = CFX_ByteString::FromUnicode(pLogFont->lfFaceName);
+  if (face.GetLength() >= LF_FACESIZE)
+    return nullptr;
+
+  FXSYS_strcpy(lfa.lfFaceName, face.c_str());
+  return AddWindowsFont(&lfa, bVert, bTranslateName);
+}
+
+CPDF_Font* CPDF_Document::AddWindowsFont(LOGFONTA* pLogFont,
+                                         FX_BOOL bVert,
+                                         FX_BOOL bTranslateName) {
+  pLogFont->lfHeight = -1000;
+  pLogFont->lfWidth = 0;
+  HGDIOBJ hFont = CreateFontIndirectA(pLogFont);
+  HDC hDC = CreateCompatibleDC(nullptr);
+  hFont = SelectObject(hDC, hFont);
+  int tm_size = GetOutlineTextMetrics(hDC, 0, nullptr);
+  if (tm_size == 0) {
+    hFont = SelectObject(hDC, hFont);
+    DeleteObject(hFont);
+    DeleteDC(hDC);
+    return nullptr;
+  }
+
+  LPBYTE tm_buf = FX_Alloc(BYTE, tm_size);
+  OUTLINETEXTMETRIC* ptm = reinterpret_cast<OUTLINETEXTMETRIC*>(tm_buf);
+  GetOutlineTextMetrics(hDC, tm_size, ptm);
+  int flags = CalculateFlags(false, pLogFont->lfItalic != 0,
+                             (pLogFont->lfPitchAndFamily & 3) == FIXED_PITCH,
+                             (pLogFont->lfPitchAndFamily & 0xf8) == FF_ROMAN,
+                             (pLogFont->lfPitchAndFamily & 0xf8) == FF_SCRIPT,
+                             pLogFont->lfCharSet == FXFONT_SYMBOL_CHARSET);
+
+  bool bCJK = pLogFont->lfCharSet == FXFONT_CHINESEBIG5_CHARSET ||
+              pLogFont->lfCharSet == FXFONT_GB2312_CHARSET ||
+              pLogFont->lfCharSet == FXFONT_HANGUL_CHARSET ||
+              pLogFont->lfCharSet == FXFONT_SHIFTJIS_CHARSET;
+  CFX_ByteString basefont;
+  if (bTranslateName && bCJK)
+    basefont = FPDF_GetPSNameFromTT(hDC);
+
+  if (basefont.IsEmpty())
+    basefont = pLogFont->lfFaceName;
+
+  int italicangle = ptm->otmItalicAngle / 10;
+  int ascend = ptm->otmrcFontBox.top;
+  int descend = ptm->otmrcFontBox.bottom;
+  int capheight = ptm->otmsCapEmHeight;
+  int bbox[4] = {ptm->otmrcFontBox.left, ptm->otmrcFontBox.bottom,
+                 ptm->otmrcFontBox.right, ptm->otmrcFontBox.top};
+  FX_Free(tm_buf);
+  basefont.Replace(" ", "");
+  CPDF_Dictionary* pBaseDict = new CPDF_Dictionary(m_pByteStringPool);
+  pBaseDict->SetNameFor("Type", "Font");
+  CPDF_Dictionary* pFontDict = pBaseDict;
+  if (!bCJK) {
+    if (pLogFont->lfCharSet == FXFONT_ANSI_CHARSET ||
+        pLogFont->lfCharSet == FXFONT_DEFAULT_CHARSET ||
+        pLogFont->lfCharSet == FXFONT_SYMBOL_CHARSET) {
+      pBaseDict->SetNameFor("Encoding", "WinAnsiEncoding");
+    } else {
+      CalculateEncodingDict(pLogFont->lfCharSet, pBaseDict);
+    }
+    int char_widths[224];
+    GetCharWidth(hDC, 32, 255, char_widths);
+    CPDF_Array* pWidths = new CPDF_Array;
+    for (size_t i = 0; i < 224; i++)
+      pWidths->AddInteger(char_widths[i]);
+    ProcessNonbCJK(pBaseDict, pLogFont->lfWeight > FW_MEDIUM,
+                   pLogFont->lfItalic != 0, basefont, pWidths);
+  } else {
+    pFontDict =
+        ProcessbCJK(pBaseDict, pLogFont->lfCharSet, bVert, basefont,
+                    [&hDC](FX_WCHAR start, FX_WCHAR end, CPDF_Array* widthArr) {
+                      InsertWidthArray(hDC, start, end, widthArr);
+                    });
+  }
+  AddIndirectObject(pBaseDict);
+  CPDF_Array* pBBox = new CPDF_Array;
+  for (int i = 0; i < 4; i++)
+    pBBox->AddInteger(bbox[i]);
+  CPDF_Dictionary* pFontDesc =
+      CalculateFontDesc(this, basefont, flags, italicangle, ascend, descend,
+                        pBBox, pLogFont->lfWeight / 5);
+  pFontDesc->SetIntegerFor("CapHeight", capheight);
+  pFontDict->SetReferenceFor("FontDescriptor", this,
+                             AddIndirectObject(pFontDesc));
+  hFont = SelectObject(hDC, hFont);
+  DeleteObject(hFont);
+  DeleteDC(hDC);
+  return LoadFont(pBaseDict);
+}
+#endif  //  _FXM_PLATFORM_ == _FXM_PLATFORM_WINDOWS_
diff --git a/core/fpdfapi/parser/cpdf_document.h b/core/fpdfapi/parser/cpdf_document.h
new file mode 100644
index 0000000000..83ceb77b08
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_document.h
@@ -0,0 +1,145 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#ifndef CORE_FPDFAPI_PARSER_CPDF_DOCUMENT_H_
+#define CORE_FPDFAPI_PARSER_CPDF_DOCUMENT_H_
+
+#include <functional>
+#include <memory>
+
+#include "core/fpdfapi/parser/cpdf_indirect_object_holder.h"
+#include "core/fpdfapi/parser/cpdf_object.h"
+#include "core/fpdfdoc/cpdf_linklist.h"
+#include "core/fxcrt/cfx_string_pool_template.h"
+#include "core/fxcrt/cfx_weak_ptr.h"
+#include "core/fxcrt/fx_basic.h"
+
+class CFX_Font;
+class CFX_Matrix;
+class CPDF_ColorSpace;
+class CPDF_DocPageData;
+class CPDF_DocRenderData;
+class CPDF_Font;
+class CPDF_FontEncoding;
+class CPDF_IccProfile;
+class CPDF_Image;
+class CPDF_Parser;
+class CPDF_Pattern;
+class CPDF_StreamAcc;
+class JBig2_DocumentContext;
+
+#define FPDFPERM_PRINT 0x0004
+#define FPDFPERM_MODIFY 0x0008
+#define FPDFPERM_EXTRACT 0x0010
+#define FPDFPERM_ANNOT_FORM 0x0020
+#define FPDFPERM_FILL_FORM 0x0100
+#define FPDFPERM_EXTRACT_ACCESS 0x0200
+#define FPDFPERM_ASSEMBLE 0x0400
+#define FPDFPERM_PRINT_HIGH 0x0800
+#define FPDF_PAGE_MAX_NUM 0xFFFFF
+
+class CPDF_Document : public CPDF_IndirectObjectHolder {
+ public:
+  explicit CPDF_Document(std::unique_ptr<CPDF_Parser> pParser);
+  ~CPDF_Document() override;
+
+  CPDF_Parser* GetParser() const { return m_pParser.get(); }
+  CPDF_Dictionary* GetRoot() const { return m_pRootDict; }
+  CPDF_Dictionary* GetInfo() const { return m_pInfoDict; }
+  CFX_WeakPtr<CFX_ByteStringPool> GetByteStringPool() const {
+    return m_pByteStringPool;
+  }
+
+  void DeletePage(int iPage);
+  int GetPageCount() const;
+
+  bool IsPageLoaded(int iPage) const;
+  CPDF_Dictionary* GetPage(int iPage);
+  int GetPageIndex(uint32_t objnum);
+  uint32_t GetUserPermissions() const;
+  CPDF_DocPageData* GetPageData() const { return m_pDocPage; }
+
+  void SetPageObjNum(int iPage, uint32_t objNum);
+
+  std::unique_ptr<JBig2_DocumentContext>* CodecContext() {
+    return &m_pCodecContext;
+  }
+  std::unique_ptr<CPDF_LinkList>* LinksContext() { return &m_pLinksContext; }
+
+  CPDF_DocRenderData* GetRenderData() const { return m_pDocRender.get(); }
+
+  // |pFontDict| must not be null.
+  CPDF_Font* LoadFont(CPDF_Dictionary* pFontDict);
+  CPDF_ColorSpace* LoadColorSpace(CPDF_Object* pCSObj,
+                                  CPDF_Dictionary* pResources = nullptr);
+
+  CPDF_Pattern* LoadPattern(CPDF_Object* pObj,
+                            FX_BOOL bShading,
+                            const CFX_Matrix& matrix);
+
+  CPDF_Image* LoadImageF(CPDF_Object* pObj);
+  CPDF_StreamAcc* LoadFontFile(CPDF_Stream* pStream);
+  CPDF_IccProfile* LoadIccProfile(CPDF_Stream* pStream);
+
+  void LoadDoc();
+  void LoadLinearizedDoc(CPDF_Dictionary* pLinearizationParams);
+  void LoadPages();
+
+  void CreateNewDoc();
+  CPDF_Dictionary* CreateNewPage(int iPage);
+
+  CPDF_Font* AddStandardFont(const FX_CHAR* font, CPDF_FontEncoding* pEncoding);
+  CPDF_Font* AddFont(CFX_Font* pFont, int charset, FX_BOOL bVert);
+#if _FXM_PLATFORM_ == _FXM_PLATFORM_WINDOWS_
+  CPDF_Font* AddWindowsFont(LOGFONTA* pLogFont,
+                            FX_BOOL bVert,
+                            FX_BOOL bTranslateName = FALSE);
+  CPDF_Font* AddWindowsFont(LOGFONTW* pLogFont,
+                            FX_BOOL bVert,
+                            FX_BOOL bTranslateName = FALSE);
+#endif
+
+ private:
+  friend class CPDF_TestDocument;
+
+  // Retrieve page count information by getting count value from the tree nodes
+  int RetrievePageCount() const;
+  CPDF_Dictionary* FindPDFPage(CPDF_Dictionary* pPages,
+                               int iPage,
+                               int nPagesToGo,
+                               int level);
+  int FindPageIndex(CPDF_Dictionary* pNode,
+                    uint32_t& skip_count,
+                    uint32_t objnum,
+                    int& index,
+                    int level = 0);
+  CPDF_Object* ParseIndirectObject(uint32_t objnum) override;
+  void LoadDocInternal();
+  size_t CalculateEncodingDict(int charset, CPDF_Dictionary* pBaseDict);
+  CPDF_Dictionary* GetPagesDict() const;
+  CPDF_Dictionary* ProcessbCJK(
+      CPDF_Dictionary* pBaseDict,
+      int charset,
+      FX_BOOL bVert,
+      CFX_ByteString basefont,
+      std::function<void(FX_WCHAR, FX_WCHAR, CPDF_Array*)> Insert);
+
+  std::unique_ptr<CPDF_Parser> m_pParser;
+  CPDF_Dictionary* m_pRootDict;
+  CPDF_Dictionary* m_pInfoDict;
+  bool m_bLinearized;
+  int m_iFirstPageNo;
+  uint32_t m_dwFirstPageObjNum;
+  // TODO(thestig): Figure out why this cannot be a std::unique_ptr.
+  CPDF_DocPageData* m_pDocPage;
+  std::unique_ptr<CPDF_DocRenderData> m_pDocRender;
+  std::unique_ptr<JBig2_DocumentContext> m_pCodecContext;
+  std::unique_ptr<CPDF_LinkList> m_pLinksContext;
+  CFX_ArrayTemplate<uint32_t> m_PageList;
+  CFX_WeakPtr<CFX_ByteStringPool> m_pByteStringPool;
+};
+
+#endif  // CORE_FPDFAPI_PARSER_CPDF_DOCUMENT_H_
diff --git a/core/fpdfapi/parser/cpdf_hint_tables.cpp b/core/fpdfapi/parser/cpdf_hint_tables.cpp
new file mode 100644
index 0000000000..045b94cac5
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_hint_tables.cpp
@@ -0,0 +1,524 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#include "core/fpdfapi/parser/cpdf_hint_tables.h"
+
+#include <limits>
+
+#include "core/fpdfapi/parser/cpdf_array.h"
+#include "core/fpdfapi/parser/cpdf_data_avail.h"
+#include "core/fpdfapi/parser/cpdf_dictionary.h"
+#include "core/fpdfapi/parser/cpdf_document.h"
+#include "core/fpdfapi/parser/cpdf_stream.h"
+#include "core/fpdfapi/parser/cpdf_stream_acc.h"
+#include "core/fxcrt/fx_safe_types.h"
+#include "third_party/base/numerics/safe_conversions.h"
+
+namespace {
+
+bool CanReadFromBitStream(const CFX_BitStream* hStream,
+                          const FX_SAFE_UINT32& bits) {
+  return bits.IsValid() && hStream->BitsRemaining() >= bits.ValueOrDie();
+}
+
+// Sanity check values from the page table header. The note in the PDF 1.7
+// reference for Table F.3 says the valid range is only 0 through 32. Though 0
+// is not useful either.
+bool IsValidPageOffsetHintTableBitCount(uint32_t bits) {
+  return bits > 0 && bits <= 32;
+}
+
+}  // namespace
+
+CPDF_HintTables::CPDF_HintTables(CPDF_DataAvail* pDataAvail,
+                                 CPDF_Dictionary* pLinearized)
+    : m_pDataAvail(pDataAvail),
+      m_pLinearizedDict(pLinearized),
+      m_nFirstPageSharedObjs(0),
+      m_szFirstPageObjOffset(0) {
+  ASSERT(m_pLinearizedDict);
+}
+
+CPDF_HintTables::~CPDF_HintTables() {}
+
+uint32_t CPDF_HintTables::GetItemLength(
+    uint32_t index,
+    const std::vector<FX_FILESIZE>& szArray) {
+  if (szArray.size() < 2 || index > szArray.size() - 2 ||
+      szArray[index] > szArray[index + 1]) {
+    return 0;
+  }
+  return szArray[index + 1] - szArray[index];
+}
+
+bool CPDF_HintTables::ReadPageHintTable(CFX_BitStream* hStream) {
+  if (!hStream || hStream->IsEOF())
+    return false;
+
+  int nStreamOffset = ReadPrimaryHintStreamOffset();
+  if (nStreamOffset < 0)
+    return false;
+
+  int nStreamLen = ReadPrimaryHintStreamLength();
+  if (nStreamLen < 1 ||
+      !pdfium::base::IsValueInRangeForNumericType<FX_FILESIZE>(nStreamLen)) {
+    return false;
+  }
+
+  const uint32_t kHeaderSize = 288;
+  if (hStream->BitsRemaining() < kHeaderSize)
+    return false;
+
+  // Item 1: The least number of objects in a page.
+  const uint32_t dwObjLeastNum = hStream->GetBits(32);
+  if (!dwObjLeastNum)
+    return false;
+
+  // Item 2: The location of the first page's page object.
+  const uint32_t dwFirstObjLoc = hStream->GetBits(32);
+  if (dwFirstObjLoc > static_cast<uint32_t>(nStreamOffset)) {
+    FX_SAFE_FILESIZE safeLoc = nStreamLen;
+    safeLoc += dwFirstObjLoc;
+    if (!safeLoc.IsValid())
+      return false;
+    m_szFirstPageObjOffset = safeLoc.ValueOrDie();
+  } else {
+    if (!pdfium::base::IsValueInRangeForNumericType<FX_FILESIZE>(dwFirstObjLoc))
+      return false;
+    m_szFirstPageObjOffset = dwFirstObjLoc;
+  }
+
+  // Item 3: The number of bits needed to represent the difference
+  // between the greatest and least number of objects in a page.
+  const uint32_t dwDeltaObjectsBits = hStream->GetBits(16);
+  if (!IsValidPageOffsetHintTableBitCount(dwDeltaObjectsBits))
+    return false;
+
+  // Item 4: The least length of a page in bytes.
+  const uint32_t dwPageLeastLen = hStream->GetBits(32);
+  if (!dwPageLeastLen)
+    return false;
+
+  // Item 5: The number of bits needed to represent the difference
+  // between the greatest and least length of a page, in bytes.
+  const uint32_t dwDeltaPageLenBits = hStream->GetBits(16);
+  if (!IsValidPageOffsetHintTableBitCount(dwDeltaPageLenBits))
+    return false;
+
+  // Skip Item 6, 7, 8, 9 total 96 bits.
+  hStream->SkipBits(96);
+
+  // Item 10: The number of bits needed to represent the greatest
+  // number of shared object references.
+  const uint32_t dwSharedObjBits = hStream->GetBits(16);
+  if (!IsValidPageOffsetHintTableBitCount(dwSharedObjBits))
+    return false;
+
+  // Item 11: The number of bits needed to represent the numerically
+  // greatest shared object identifier used by the pages.
+  const uint32_t dwSharedIdBits = hStream->GetBits(16);
+  if (!IsValidPageOffsetHintTableBitCount(dwSharedIdBits))
+    return false;
+
+  // Item 12: The number of bits needed to represent the numerator of
+  // the fractional position for each shared object reference. For each
+  // shared object referenced from a page, there is an indication of
+  // where in the page's content stream the object is first referenced.
+  const uint32_t dwSharedNumeratorBits = hStream->GetBits(16);
+  if (!IsValidPageOffsetHintTableBitCount(dwSharedNumeratorBits))
+    return false;
+
+  // Item 13: Skip Item 13 which has 16 bits.
+  hStream->SkipBits(16);
+
+  const int nPages = GetNumberOfPages();
+  if (nPages < 1 || nPages >= FPDF_PAGE_MAX_NUM)
+    return false;
+
+  const uint32_t dwPages = pdfium::base::checked_cast<uint32_t>(nPages);
+  FX_SAFE_UINT32 required_bits = dwDeltaObjectsBits;
+  required_bits *= dwPages;
+  if (!CanReadFromBitStream(hStream, required_bits))
+    return false;
+
+  for (int i = 0; i < nPages; ++i) {
+    FX_SAFE_UINT32 safeDeltaObj = hStream->GetBits(dwDeltaObjectsBits);
+    safeDeltaObj += dwObjLeastNum;
+    if (!safeDeltaObj.IsValid())
+      return false;
+    m_dwDeltaNObjsArray.push_back(safeDeltaObj.ValueOrDie());
+  }
+  hStream->ByteAlign();
+
+  required_bits = dwDeltaPageLenBits;
+  required_bits *= dwPages;
+  if (!CanReadFromBitStream(hStream, required_bits))
+    return false;
+
+  std::vector<uint32_t> dwPageLenArray;
+  for (int i = 0; i < nPages; ++i) {
+    FX_SAFE_UINT32 safePageLen = hStream->GetBits(dwDeltaPageLenBits);
+    safePageLen += dwPageLeastLen;
+    if (!safePageLen.IsValid())
+      return false;
+
+    dwPageLenArray.push_back(safePageLen.ValueOrDie());
+  }
+
+  int nOffsetE = GetEndOfFirstPageOffset();
+  if (nOffsetE < 0)
+    return false;
+
+  int nFirstPageNum = GetFirstPageNumber();
+  if (nFirstPageNum < 0 || nFirstPageNum > std::numeric_limits<int>::max() - 1)
+    return false;
+
+  for (int i = 0; i < nPages; ++i) {
+    if (i == nFirstPageNum) {
+      m_szPageOffsetArray.push_back(m_szFirstPageObjOffset);
+    } else if (i == nFirstPageNum + 1) {
+      if (i == 1) {
+        m_szPageOffsetArray.push_back(nOffsetE);
+      } else {
+        m_szPageOffsetArray.push_back(m_szPageOffsetArray[i - 2] +
+                                      dwPageLenArray[i - 2]);
+      }
+    } else {
+      if (i == 0) {
+        m_szPageOffsetArray.push_back(nOffsetE);
+      } else {
+        m_szPageOffsetArray.push_back(m_szPageOffsetArray[i - 1] +
+                                      dwPageLenArray[i - 1]);
+      }
+    }
+  }
+
+  m_szPageOffsetArray.push_back(m_szPageOffsetArray[nPages - 1] +
+                                dwPageLenArray[nPages - 1]);
+  hStream->ByteAlign();
+
+  // Number of shared objects.
+  required_bits = dwSharedObjBits;
+  required_bits *= dwPages;
+  if (!CanReadFromBitStream(hStream, required_bits))
+    return false;
+
+  for (int i = 0; i < nPages; i++)
+    m_dwNSharedObjsArray.push_back(hStream->GetBits(dwSharedObjBits));
+  hStream->ByteAlign();
+
+  // Array of identifiers, size = nshared_objects.
+  for (int i = 0; i < nPages; i++) {
+    required_bits = dwSharedIdBits;
+    required_bits *= m_dwNSharedObjsArray[i];
+    if (!CanReadFromBitStream(hStream, required_bits))
+      return false;
+
+    for (uint32_t j = 0; j < m_dwNSharedObjsArray[i]; j++)
+      m_dwIdentifierArray.push_back(hStream->GetBits(dwSharedIdBits));
+  }
+  hStream->ByteAlign();
+
+  for (int i = 0; i < nPages; i++) {
+    FX_SAFE_UINT32 safeSize = m_dwNSharedObjsArray[i];
+    safeSize *= dwSharedNumeratorBits;
+    if (!CanReadFromBitStream(hStream, safeSize))
+      return false;
+
+    hStream->SkipBits(safeSize.ValueOrDie());
+  }
+  hStream->ByteAlign();
+
+  FX_SAFE_UINT32 safeTotalPageLen = dwPages;
+  safeTotalPageLen *= dwDeltaPageLenBits;
+  if (!CanReadFromBitStream(hStream, safeTotalPageLen))
+    return false;
+
+  hStream->SkipBits(safeTotalPageLen.ValueOrDie());
+  hStream->ByteAlign();
+  return true;
+}
+
+bool CPDF_HintTables::ReadSharedObjHintTable(CFX_BitStream* hStream,
+                                             uint32_t offset) {
+  if (!hStream || hStream->IsEOF())
+    return false;
+
+  int nStreamOffset = ReadPrimaryHintStreamOffset();
+  int nStreamLen = ReadPrimaryHintStreamLength();
+  if (nStreamOffset < 0 || nStreamLen < 1)
+    return false;
+
+  FX_SAFE_UINT32 bit_offset = offset;
+  bit_offset *= 8;
+  if (!bit_offset.IsValid() || hStream->GetPos() > bit_offset.ValueOrDie())
+    return false;
+  hStream->SkipBits(bit_offset.ValueOrDie() - hStream->GetPos());
+
+  const uint32_t kHeaderSize = 192;
+  if (hStream->BitsRemaining() < kHeaderSize)
+    return false;
+
+  // Item 1: The object number of the first object in the shared objects
+  // section.
+  uint32_t dwFirstSharedObjNum = hStream->GetBits(32);
+
+  // Item 2: The location of the first object in the shared objects section.
+  uint32_t dwFirstSharedObjLoc = hStream->GetBits(32);
+  if (dwFirstSharedObjLoc > static_cast<uint32_t>(nStreamOffset))
+    dwFirstSharedObjLoc += nStreamLen;
+
+  // Item 3: The number of shared object entries for the first page.
+  m_nFirstPageSharedObjs = hStream->GetBits(32);
+
+  // Item 4: The number of shared object entries for the shared objects
+  // section, including the number of shared object entries for the first page.
+  uint32_t dwSharedObjTotal = hStream->GetBits(32);
+
+  // Item 5: The number of bits needed to represent the greatest number of
+  // objects in a shared object group. Skipped.
+  hStream->SkipBits(16);
+
+  // Item 6: The least length of a shared object group in bytes.
+  uint32_t dwGroupLeastLen = hStream->GetBits(32);
+
+  // Item 7: The number of bits needed to represent the difference between the
+  // greatest and least length of a shared object group, in bytes.
+  uint32_t dwDeltaGroupLen = hStream->GetBits(16);
+
+  if (dwFirstSharedObjNum >= CPDF_Parser::kMaxObjectNumber ||
+      m_nFirstPageSharedObjs >= CPDF_Parser::kMaxObjectNumber ||
+      dwSharedObjTotal >= CPDF_Parser::kMaxObjectNumber) {
+    return false;
+  }
+
+  int nFirstPageObjNum = GetFirstPageObjectNumber();
+  if (nFirstPageObjNum < 0)
+    return false;
+
+  uint32_t dwPrevObjLen = 0;
+  uint32_t dwCurObjLen = 0;
+  FX_SAFE_UINT32 required_bits = dwSharedObjTotal;
+  required_bits *= dwDeltaGroupLen;
+  if (!CanReadFromBitStream(hStream, required_bits))
+    return false;
+
+  for (uint32_t i = 0; i < dwSharedObjTotal; ++i) {
+    dwPrevObjLen = dwCurObjLen;
+    FX_SAFE_UINT32 safeObjLen = hStream->GetBits(dwDeltaGroupLen);
+    safeObjLen += dwGroupLeastLen;
+    if (!safeObjLen.IsValid())
+      return false;
+
+    dwCurObjLen = safeObjLen.ValueOrDie();
+    if (i < m_nFirstPageSharedObjs) {
+      m_dwSharedObjNumArray.push_back(nFirstPageObjNum + i);
+      if (i == 0)
+        m_szSharedObjOffsetArray.push_back(m_szFirstPageObjOffset);
+    } else {
+      FX_SAFE_UINT32 safeObjNum = dwFirstSharedObjNum;
+      safeObjNum += i - m_nFirstPageSharedObjs;
+      if (!safeObjNum.IsValid())
+        return false;
+
+      m_dwSharedObjNumArray.push_back(safeObjNum.ValueOrDie());
+      if (i == m_nFirstPageSharedObjs) {
+        FX_SAFE_FILESIZE safeLoc = dwFirstSharedObjLoc;
+        if (!safeLoc.IsValid())
+          return false;
+
+        m_szSharedObjOffsetArray.push_back(safeLoc.ValueOrDie());
+      }
+    }
+
+    if (i != 0 && i != m_nFirstPageSharedObjs) {
+      FX_SAFE_FILESIZE safeLoc = dwPrevObjLen;
+      safeLoc += m_szSharedObjOffsetArray[i - 1];
+      if (!safeLoc.IsValid())
+        return false;
+
+      m_szSharedObjOffsetArray.push_back(safeLoc.ValueOrDie());
+    }
+  }
+
+  if (dwSharedObjTotal > 0) {
+    FX_SAFE_FILESIZE safeLoc = dwCurObjLen;
+    safeLoc += m_szSharedObjOffsetArray[dwSharedObjTotal - 1];
+    if (!safeLoc.IsValid())
+      return false;
+
+    m_szSharedObjOffsetArray.push_back(safeLoc.ValueOrDie());
+  }
+
+  hStream->ByteAlign();
+  if (hStream->BitsRemaining() < dwSharedObjTotal)
+    return false;
+
+  hStream->SkipBits(dwSharedObjTotal);
+  hStream->ByteAlign();
+  return true;
+}
+
+bool CPDF_HintTables::GetPagePos(uint32_t index,
+                                 FX_FILESIZE* szPageStartPos,
+                                 FX_FILESIZE* szPageLength,
+                                 uint32_t* dwObjNum) {
+  *szPageStartPos = m_szPageOffsetArray[index];
+  *szPageLength = GetItemLength(index, m_szPageOffsetArray);
+
+  int nFirstPageObjNum = GetFirstPageObjectNumber();
+  if (nFirstPageObjNum < 0)
+    return false;
+
+  int nFirstPageNum = GetFirstPageNumber();
+  if (!pdfium::base::IsValueInRangeForNumericType<uint32_t>(nFirstPageNum))
+    return false;
+
+  uint32_t dwFirstPageNum = static_cast<uint32_t>(nFirstPageNum);
+  if (index == dwFirstPageNum) {
+    *dwObjNum = nFirstPageObjNum;
+    return true;
+  }
+
+  // The object number of remaining pages starts from 1.
+  *dwObjNum = 1;
+  for (uint32_t i = 0; i < index; ++i) {
+    if (i == dwFirstPageNum)
+      continue;
+    *dwObjNum += m_dwDeltaNObjsArray[i];
+  }
+  return true;
+}
+
+CPDF_DataAvail::DocAvailStatus CPDF_HintTables::CheckPage(
+    uint32_t index,
+    CPDF_DataAvail::DownloadHints* pHints) {
+  if (!pHints)
+    return CPDF_DataAvail::DataError;
+
+  int nFirstPageNum = GetFirstPageNumber();
+  if (!pdfium::base::IsValueInRangeForNumericType<uint32_t>(nFirstPageNum))
+    return CPDF_DataAvail::DataError;
+
+  if (index == static_cast<uint32_t>(nFirstPageNum))
+    return CPDF_DataAvail::DataAvailable;
+
+  uint32_t dwLength = GetItemLength(index, m_szPageOffsetArray);
+  // If two pages have the same offset, it should be treated as an error.
+  if (!dwLength)
+    return CPDF_DataAvail::DataError;
+
+  if (!m_pDataAvail->IsDataAvail(m_szPageOffsetArray[index], dwLength, pHints))
+    return CPDF_DataAvail::DataNotAvailable;
+
+  // Download data of shared objects in the page.
+  uint32_t offset = 0;
+  for (uint32_t i = 0; i < index; ++i)
+    offset += m_dwNSharedObjsArray[i];
+
+  int nFirstPageObjNum = GetFirstPageObjectNumber();
+  if (nFirstPageObjNum < 0)
+    return CPDF_DataAvail::DataError;
+
+  uint32_t dwIndex = 0;
+  uint32_t dwObjNum = 0;
+  for (uint32_t j = 0; j < m_dwNSharedObjsArray[index]; ++j) {
+    dwIndex = m_dwIdentifierArray[offset + j];
+    if (dwIndex >= m_dwSharedObjNumArray.size())
+      return CPDF_DataAvail::DataNotAvailable;
+
+    dwObjNum = m_dwSharedObjNumArray[dwIndex];
+    if (dwObjNum >= static_cast<uint32_t>(nFirstPageObjNum) &&
+        dwObjNum <
+            static_cast<uint32_t>(nFirstPageObjNum) + m_nFirstPageSharedObjs) {
+      continue;
+    }
+
+    dwLength = GetItemLength(dwIndex, m_szSharedObjOffsetArray);
+    // If two objects have the same offset, it should be treated as an error.
+    if (!dwLength)
+      return CPDF_DataAvail::DataError;
+
+    if (!m_pDataAvail->IsDataAvail(m_szSharedObjOffsetArray[dwIndex], dwLength,
+                                   pHints)) {
+      return CPDF_DataAvail::DataNotAvailable;
+    }
+  }
+  return CPDF_DataAvail::DataAvailable;
+}
+
+bool CPDF_HintTables::LoadHintStream(CPDF_Stream* pHintStream) {
+  if (!pHintStream)
+    return false;
+
+  CPDF_Dictionary* pDict = pHintStream->GetDict();
+  CPDF_Object* pOffset = pDict ? pDict->GetObjectFor("S") : nullptr;
+  if (!pOffset || !pOffset->IsNumber())
+    return false;
+
+  int shared_hint_table_offset = pOffset->GetInteger();
+  if (shared_hint_table_offset <= 0)
+    return false;
+
+  CPDF_StreamAcc acc;
+  acc.LoadAllData(pHintStream);
+
+  uint32_t size = acc.GetSize();
+  // The header section of page offset hint table is 36 bytes.
+  // The header section of shared object hint table is 24 bytes.
+  // Hint table has at least 60 bytes.
+  const uint32_t kMinStreamLength = 60;
+  if (size < kMinStreamLength)
+    return false;
+
+  FX_SAFE_UINT32 safe_shared_hint_table_offset = shared_hint_table_offset;
+  if (!safe_shared_hint_table_offset.IsValid() ||
+      size < safe_shared_hint_table_offset.ValueOrDie()) {
+    return false;
+  }
+
+  CFX_BitStream bs;
+  bs.Init(acc.GetData(), size);
+  return ReadPageHintTable(&bs) &&
+         ReadSharedObjHintTable(&bs, shared_hint_table_offset);
+}
+
+int CPDF_HintTables::GetEndOfFirstPageOffset() const {
+  CPDF_Object* pOffsetE = m_pLinearizedDict->GetDirectObjectFor("E");
+  return pOffsetE ? pOffsetE->GetInteger() : -1;
+}
+
+int CPDF_HintTables::GetNumberOfPages() const {
+  CPDF_Object* pPageNum = m_pLinearizedDict->GetDirectObjectFor("N");
+  return pPageNum ? pPageNum->GetInteger() : 0;
+}
+
+int CPDF_HintTables::GetFirstPageObjectNumber() const {
+  CPDF_Object* pFirstPageObj = m_pLinearizedDict->GetDirectObjectFor("O");
+  return pFirstPageObj ? pFirstPageObj->GetInteger() : -1;
+}
+
+int CPDF_HintTables::GetFirstPageNumber() const {
+  CPDF_Object* pFirstPageNum = m_pLinearizedDict->GetDirectObjectFor("P");
+  return pFirstPageNum ? pFirstPageNum->GetInteger() : 0;
+}
+
+int CPDF_HintTables::ReadPrimaryHintStreamOffset() const {
+  return ReadPrimaryHintStream(0);
+}
+
+int CPDF_HintTables::ReadPrimaryHintStreamLength() const {
+  return ReadPrimaryHintStream(1);
+}
+
+int CPDF_HintTables::ReadPrimaryHintStream(int index) const {
+  CPDF_Array* pRange = m_pLinearizedDict->GetArrayFor("H");
+  if (!pRange)
+    return -1;
+
+  CPDF_Object* pStreamLen = pRange->GetDirectObjectAt(index);
+  return pStreamLen ? pStreamLen->GetInteger() : -1;
+}
diff --git a/core/fpdfapi/parser/cpdf_hint_tables.h b/core/fpdfapi/parser/cpdf_hint_tables.h
new file mode 100644
index 0000000000..84f48cf41f
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_hint_tables.h
@@ -0,0 +1,71 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#ifndef CORE_FPDFAPI_PARSER_CPDF_HINT_TABLES_H_
+#define CORE_FPDFAPI_PARSER_CPDF_HINT_TABLES_H_
+
+#include <vector>
+
+#include "core/fpdfapi/parser/cpdf_data_avail.h"
+#include "core/fxcrt/fx_basic.h"
+#include "core/fxcrt/fx_stream.h"
+
+class CFX_BitStream;
+class CPDF_Dictionary;
+class CPDF_Stream;
+
+class CPDF_HintTables {
+ public:
+  CPDF_HintTables(CPDF_DataAvail* pDataAvail, CPDF_Dictionary* pLinearized);
+  virtual ~CPDF_HintTables();
+
+  bool GetPagePos(uint32_t index,
+                  FX_FILESIZE* szPageStartPos,
+                  FX_FILESIZE* szPageLength,
+                  uint32_t* dwObjNum);
+
+  CPDF_DataAvail::DocAvailStatus CheckPage(
+      uint32_t index,
+      CPDF_DataAvail::DownloadHints* pHints);
+
+  bool LoadHintStream(CPDF_Stream* pHintStream);
+
+ protected:
+  bool ReadPageHintTable(CFX_BitStream* hStream);
+  bool ReadSharedObjHintTable(CFX_BitStream* hStream, uint32_t offset);
+
+ private:
+  // Tests can override.
+  virtual int GetEndOfFirstPageOffset() const;
+  virtual int GetNumberOfPages() const;
+  virtual int GetFirstPageObjectNumber() const;
+  virtual int GetFirstPageNumber() const;
+  virtual int ReadPrimaryHintStreamOffset() const;
+  virtual int ReadPrimaryHintStreamLength() const;
+
+  // Helper for the ReadPrimaryHintStream methods above.
+  int ReadPrimaryHintStream(int index) const;
+
+  uint32_t GetItemLength(uint32_t index,
+                         const std::vector<FX_FILESIZE>& szArray);
+
+  // Owner, outlives this object.
+  CPDF_DataAvail* const m_pDataAvail;
+
+  // Owned by |m_pDataAvail|.
+  CPDF_Dictionary* const m_pLinearizedDict;
+
+  uint32_t m_nFirstPageSharedObjs;
+  FX_FILESIZE m_szFirstPageObjOffset;
+  std::vector<uint32_t> m_dwDeltaNObjsArray;
+  std::vector<uint32_t> m_dwNSharedObjsArray;
+  std::vector<uint32_t> m_dwSharedObjNumArray;
+  std::vector<uint32_t> m_dwIdentifierArray;
+  std::vector<FX_FILESIZE> m_szPageOffsetArray;
+  std::vector<FX_FILESIZE> m_szSharedObjOffsetArray;
+};
+
+#endif  // CORE_FPDFAPI_PARSER_CPDF_HINT_TABLES_H_
diff --git a/core/fpdfapi/parser/cpdf_indirect_object_holder.cpp b/core/fpdfapi/parser/cpdf_indirect_object_holder.cpp
new file mode 100644
index 0000000000..6e549de5a7
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_indirect_object_holder.cpp
@@ -0,0 +1,79 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#include "core/fpdfapi/parser/cpdf_indirect_object_holder.h"
+
+#include "core/fpdfapi/parser/cpdf_object.h"
+#include "core/fpdfapi/parser/cpdf_parser.h"
+
+CPDF_IndirectObjectHolder::CPDF_IndirectObjectHolder() : m_LastObjNum(0) {}
+
+CPDF_IndirectObjectHolder::~CPDF_IndirectObjectHolder() {}
+
+CPDF_Object* CPDF_IndirectObjectHolder::GetIndirectObject(
+    uint32_t objnum) const {
+  auto it = m_IndirectObjs.find(objnum);
+  return it != m_IndirectObjs.end() ? it->second.get() : nullptr;
+}
+
+CPDF_Object* CPDF_IndirectObjectHolder::GetOrParseIndirectObject(
+    uint32_t objnum) {
+  if (objnum == 0)
+    return nullptr;
+
+  CPDF_Object* pObj = GetIndirectObject(objnum);
+  if (pObj)
+    return pObj->GetObjNum() != CPDF_Object::kInvalidObjNum ? pObj : nullptr;
+
+  pObj = ParseIndirectObject(objnum);
+  if (!pObj)
+    return nullptr;
+
+  pObj->m_ObjNum = objnum;
+  m_LastObjNum = std::max(m_LastObjNum, objnum);
+  m_IndirectObjs[objnum].reset(pObj);
+  return pObj;
+}
+
+CPDF_Object* CPDF_IndirectObjectHolder::ParseIndirectObject(uint32_t objnum) {
+  return nullptr;
+}
+
+uint32_t CPDF_IndirectObjectHolder::AddIndirectObject(CPDF_Object* pObj) {
+  if (pObj->m_ObjNum)
+    return pObj->m_ObjNum;
+
+  m_LastObjNum++;
+  m_IndirectObjs[m_LastObjNum].release();  // TODO(tsepez): stop this leak.
+  m_IndirectObjs[m_LastObjNum].reset(pObj);
+  pObj->m_ObjNum = m_LastObjNum;
+  return m_LastObjNum;
+}
+
+bool CPDF_IndirectObjectHolder::ReplaceIndirectObjectIfHigherGeneration(
+    uint32_t objnum,
+    CPDF_Object* pObj) {
+  if (!objnum || !pObj)
+    return false;
+
+  CPDF_Object* pOldObj = GetIndirectObject(objnum);
+  if (pOldObj && pObj->GetGenNum() <= pOldObj->GetGenNum()) {
+    delete pObj;
+    return false;
+  }
+  pObj->m_ObjNum = objnum;
+  m_IndirectObjs[objnum].reset(pObj);
+  m_LastObjNum = std::max(m_LastObjNum, objnum);
+  return true;
+}
+
+void CPDF_IndirectObjectHolder::ReleaseIndirectObject(uint32_t objnum) {
+  CPDF_Object* pObj = GetIndirectObject(objnum);
+  if (!pObj || pObj->GetObjNum() == CPDF_Object::kInvalidObjNum)
+    return;
+
+  m_IndirectObjs.erase(objnum);
+}
diff --git a/core/fpdfapi/parser/cpdf_indirect_object_holder.h b/core/fpdfapi/parser/cpdf_indirect_object_holder.h
new file mode 100644
index 0000000000..da4e942b5d
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_indirect_object_holder.h
@@ -0,0 +1,48 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#ifndef CORE_FPDFAPI_PARSER_CPDF_INDIRECT_OBJECT_HOLDER_H_
+#define CORE_FPDFAPI_PARSER_CPDF_INDIRECT_OBJECT_HOLDER_H_
+
+#include <map>
+#include <memory>
+
+#include "core/fxcrt/fx_system.h"
+
+class CPDF_Object;
+
+class CPDF_IndirectObjectHolder {
+ public:
+  using const_iterator =
+      std::map<uint32_t, std::unique_ptr<CPDF_Object>>::const_iterator;
+
+  CPDF_IndirectObjectHolder();
+  virtual ~CPDF_IndirectObjectHolder();
+
+  CPDF_Object* GetIndirectObject(uint32_t objnum) const;
+  CPDF_Object* GetOrParseIndirectObject(uint32_t objnum);
+  void ReleaseIndirectObject(uint32_t objnum);
+
+  // Take ownership of |pObj|.
+  uint32_t AddIndirectObject(CPDF_Object* pObj);
+  bool ReplaceIndirectObjectIfHigherGeneration(uint32_t objnum,
+                                               CPDF_Object* pObj);
+
+  uint32_t GetLastObjNum() const { return m_LastObjNum; }
+  void SetLastObjNum(uint32_t objnum) { m_LastObjNum = objnum; }
+
+  const_iterator begin() const { return m_IndirectObjs.begin(); }
+  const_iterator end() const { return m_IndirectObjs.end(); }
+
+ protected:
+  virtual CPDF_Object* ParseIndirectObject(uint32_t objnum);
+
+ private:
+  uint32_t m_LastObjNum;
+  std::map<uint32_t, std::unique_ptr<CPDF_Object>> m_IndirectObjs;
+};
+
+#endif  // CORE_FPDFAPI_PARSER_CPDF_INDIRECT_OBJECT_HOLDER_H_
diff --git a/core/fpdfapi/parser/cpdf_name.cpp b/core/fpdfapi/parser/cpdf_name.cpp
new file mode 100644
index 0000000000..5cc8479c3b
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_name.cpp
@@ -0,0 +1,45 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#include "core/fpdfapi/parser/cpdf_name.h"
+
+#include "core/fpdfapi/parser/fpdf_parser_decode.h"
+
+CPDF_Name::CPDF_Name(const CFX_ByteString& str) : m_Name(str) {}
+
+CPDF_Name::~CPDF_Name() {}
+
+CPDF_Object::Type CPDF_Name::GetType() const {
+  return NAME;
+}
+
+CPDF_Object* CPDF_Name::Clone() const {
+  return new CPDF_Name(m_Name);
+}
+
+CFX_ByteString CPDF_Name::GetString() const {
+  return m_Name;
+}
+
+void CPDF_Name::SetString(const CFX_ByteString& str) {
+  m_Name = str;
+}
+
+bool CPDF_Name::IsName() const {
+  return true;
+}
+
+CPDF_Name* CPDF_Name::AsName() {
+  return this;
+}
+
+const CPDF_Name* CPDF_Name::AsName() const {
+  return this;
+}
+
+CFX_WideString CPDF_Name::GetUnicodeText() const {
+  return PDF_DecodeText(m_Name);
+}
diff --git a/core/fpdfapi/parser/cpdf_name.h b/core/fpdfapi/parser/cpdf_name.h
new file mode 100644
index 0000000000..e6b460de39
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_name.h
@@ -0,0 +1,32 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#ifndef CORE_FPDFAPI_PARSER_CPDF_NAME_H_
+#define CORE_FPDFAPI_PARSER_CPDF_NAME_H_
+
+#include "core/fpdfapi/parser/cpdf_object.h"
+
+class CPDF_Name : public CPDF_Object {
+ public:
+  explicit CPDF_Name(const CFX_ByteString& str);
+
+  // CPDF_Object.
+  Type GetType() const override;
+  CPDF_Object* Clone() const override;
+  CFX_ByteString GetString() const override;
+  CFX_WideString GetUnicodeText() const override;
+  void SetString(const CFX_ByteString& str) override;
+  bool IsName() const override;
+  CPDF_Name* AsName() override;
+  const CPDF_Name* AsName() const override;
+
+ protected:
+  ~CPDF_Name() override;
+
+  CFX_ByteString m_Name;
+};
+
+#endif  // CORE_FPDFAPI_PARSER_CPDF_NAME_H_
diff --git a/core/fpdfapi/parser/cpdf_null.cpp b/core/fpdfapi/parser/cpdf_null.cpp
new file mode 100644
index 0000000000..dd23101aa8
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_null.cpp
@@ -0,0 +1,17 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#include "core/fpdfapi/parser/cpdf_null.h"
+
+CPDF_Null::CPDF_Null() {}
+
+CPDF_Object::Type CPDF_Null::GetType() const {
+  return NULLOBJ;
+}
+
+CPDF_Object* CPDF_Null::Clone() const {
+  return new CPDF_Null;
+}
diff --git a/core/fpdfapi/parser/cpdf_null.h b/core/fpdfapi/parser/cpdf_null.h
new file mode 100644
index 0000000000..2b8b053b99
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_null.h
@@ -0,0 +1,21 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#ifndef CORE_FPDFAPI_PARSER_CPDF_NULL_H_
+#define CORE_FPDFAPI_PARSER_CPDF_NULL_H_
+
+#include "core/fpdfapi/parser/cpdf_object.h"
+
+class CPDF_Null : public CPDF_Object {
+ public:
+  CPDF_Null();
+
+  // CPDF_Object.
+  Type GetType() const override;
+  CPDF_Object* Clone() const override;
+};
+
+#endif  // CORE_FPDFAPI_PARSER_CPDF_NULL_H_
diff --git a/core/fpdfapi/parser/cpdf_number.cpp b/core/fpdfapi/parser/cpdf_number.cpp
new file mode 100644
index 0000000000..3ae629ede9
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_number.cpp
@@ -0,0 +1,55 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#include "core/fpdfapi/parser/cpdf_number.h"
+
+CPDF_Number::CPDF_Number() : m_bInteger(true), m_Integer(0) {}
+
+CPDF_Number::CPDF_Number(int value) : m_bInteger(true), m_Integer(value) {}
+
+CPDF_Number::CPDF_Number(FX_FLOAT value) : m_bInteger(false), m_Float(value) {}
+
+CPDF_Number::CPDF_Number(const CFX_ByteStringC& str)
+    : m_bInteger(FX_atonum(str, &m_Integer)) {}
+
+CPDF_Number::~CPDF_Number() {}
+
+CPDF_Object::Type CPDF_Number::GetType() const {
+  return NUMBER;
+}
+
+CPDF_Object* CPDF_Number::Clone() const {
+  return m_bInteger ? new CPDF_Number(m_Integer) : new CPDF_Number(m_Float);
+}
+
+FX_FLOAT CPDF_Number::GetNumber() const {
+  return m_bInteger ? static_cast<FX_FLOAT>(m_Integer) : m_Float;
+}
+
+int CPDF_Number::GetInteger() const {
+  return m_bInteger ? m_Integer : static_cast<int>(m_Float);
+}
+
+bool CPDF_Number::IsNumber() const {
+  return true;
+}
+
+CPDF_Number* CPDF_Number::AsNumber() {
+  return this;
+}
+
+const CPDF_Number* CPDF_Number::AsNumber() const {
+  return this;
+}
+
+void CPDF_Number::SetString(const CFX_ByteString& str) {
+  m_bInteger = FX_atonum(str.AsStringC(), &m_Integer);
+}
+
+CFX_ByteString CPDF_Number::GetString() const {
+  return m_bInteger ? CFX_ByteString::FormatInteger(m_Integer, FXFORMAT_SIGNED)
+                    : CFX_ByteString::FormatFloat(m_Float);
+}
diff --git a/core/fpdfapi/parser/cpdf_number.h b/core/fpdfapi/parser/cpdf_number.h
new file mode 100644
index 0000000000..8c708e93f1
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_number.h
@@ -0,0 +1,44 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#ifndef CORE_FPDFAPI_PARSER_CPDF_NUMBER_H_
+#define CORE_FPDFAPI_PARSER_CPDF_NUMBER_H_
+
+#include "core/fpdfapi/parser/cpdf_object.h"
+#include "core/fxcrt/fx_string.h"
+#include "core/fxcrt/fx_system.h"
+
+class CPDF_Number : public CPDF_Object {
+ public:
+  CPDF_Number();
+  explicit CPDF_Number(int value);
+  explicit CPDF_Number(FX_FLOAT value);
+  explicit CPDF_Number(const CFX_ByteStringC& str);
+
+  // CPDF_Object.
+  Type GetType() const override;
+  CPDF_Object* Clone() const override;
+  CFX_ByteString GetString() const override;
+  FX_FLOAT GetNumber() const override;
+  int GetInteger() const override;
+  void SetString(const CFX_ByteString& str) override;
+  bool IsNumber() const override;
+  CPDF_Number* AsNumber() override;
+  const CPDF_Number* AsNumber() const override;
+
+  bool IsInteger() const { return m_bInteger; }
+
+ protected:
+  ~CPDF_Number() override;
+
+  bool m_bInteger;
+  union {
+    int m_Integer;
+    FX_FLOAT m_Float;
+  };
+};
+
+#endif  // CORE_FPDFAPI_PARSER_CPDF_NUMBER_H_
diff --git a/core/fpdfapi/parser/cpdf_object.cpp b/core/fpdfapi/parser/cpdf_object.cpp
new file mode 100644
index 0000000000..3bf0a953db
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_object.cpp
@@ -0,0 +1,165 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#include "core/fpdfapi/parser/cpdf_object.h"
+
+#include <algorithm>
+
+#include "core/fpdfapi/parser/cpdf_array.h"
+#include "core/fpdfapi/parser/cpdf_dictionary.h"
+#include "core/fpdfapi/parser/cpdf_indirect_object_holder.h"
+#include "core/fpdfapi/parser/cpdf_parser.h"
+#include "core/fpdfapi/parser/fpdf_parser_decode.h"
+#include "core/fxcrt/fx_string.h"
+#include "third_party/base/stl_util.h"
+
+CPDF_Object::~CPDF_Object() {}
+
+CPDF_Object* CPDF_Object::GetDirect() const {
+  return const_cast<CPDF_Object*>(this);
+}
+
+CPDF_Object* CPDF_Object::CloneObjectNonCyclic(bool bDirect) const {
+  std::set<const CPDF_Object*> visited_objs;
+  return CloneNonCyclic(bDirect, &visited_objs);
+}
+
+CPDF_Object* CPDF_Object::CloneDirectObject() const {
+  return CloneObjectNonCyclic(true);
+}
+
+CPDF_Object* CPDF_Object::CloneNonCyclic(
+    bool bDirect,
+    std::set<const CPDF_Object*>* pVisited) const {
+  return Clone();
+}
+
+void CPDF_Object::Release() {
+  if (m_ObjNum)
+    return;
+
+  delete this;
+}
+
+CFX_ByteString CPDF_Object::GetString() const {
+  return CFX_ByteString();
+}
+
+CFX_WideString CPDF_Object::GetUnicodeText() const {
+  return CFX_WideString();
+}
+
+FX_FLOAT CPDF_Object::GetNumber() const {
+  return 0;
+}
+
+int CPDF_Object::GetInteger() const {
+  return 0;
+}
+
+CPDF_Dictionary* CPDF_Object::GetDict() const {
+  return nullptr;
+}
+
+void CPDF_Object::SetString(const CFX_ByteString& str) {
+  ASSERT(FALSE);
+}
+
+bool CPDF_Object::IsArray() const {
+  return false;
+}
+
+bool CPDF_Object::IsBoolean() const {
+  return false;
+}
+
+bool CPDF_Object::IsDictionary() const {
+  return false;
+}
+
+bool CPDF_Object::IsName() const {
+  return false;
+}
+
+bool CPDF_Object::IsNumber() const {
+  return false;
+}
+
+bool CPDF_Object::IsReference() const {
+  return false;
+}
+
+bool CPDF_Object::IsStream() const {
+  return false;
+}
+
+bool CPDF_Object::IsString() const {
+  return false;
+}
+
+CPDF_Array* CPDF_Object::AsArray() {
+  return nullptr;
+}
+
+const CPDF_Array* CPDF_Object::AsArray() const {
+  return nullptr;
+}
+
+CPDF_Boolean* CPDF_Object::AsBoolean() {
+  return nullptr;
+}
+
+const CPDF_Boolean* CPDF_Object::AsBoolean() const {
+  return nullptr;
+}
+
+CPDF_Dictionary* CPDF_Object::AsDictionary() {
+  return nullptr;
+}
+
+const CPDF_Dictionary* CPDF_Object::AsDictionary() const {
+  return nullptr;
+}
+
+CPDF_Name* CPDF_Object::AsName() {
+  return nullptr;
+}
+
+const CPDF_Name* CPDF_Object::AsName() const {
+  return nullptr;
+}
+
+CPDF_Number* CPDF_Object::AsNumber() {
+  return nullptr;
+}
+
+const CPDF_Number* CPDF_Object::AsNumber() const {
+  return nullptr;
+}
+
+CPDF_Reference* CPDF_Object::AsReference() {
+  return nullptr;
+}
+
+const CPDF_Reference* CPDF_Object::AsReference() const {
+  return nullptr;
+}
+
+CPDF_Stream* CPDF_Object::AsStream() {
+  return nullptr;
+}
+
+const CPDF_Stream* CPDF_Object::AsStream() const {
+  return nullptr;
+}
+
+CPDF_String* CPDF_Object::AsString() {
+  return nullptr;
+}
+
+const CPDF_String* CPDF_Object::AsString() const {
+  return nullptr;
+}
diff --git a/core/fpdfapi/parser/cpdf_object.h b/core/fpdfapi/parser/cpdf_object.h
new file mode 100644
index 0000000000..75400f3a53
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_object.h
@@ -0,0 +1,183 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#ifndef CORE_FPDFAPI_PARSER_CPDF_OBJECT_H_
+#define CORE_FPDFAPI_PARSER_CPDF_OBJECT_H_
+
+#include <memory>
+#include <set>
+
+#include "core/fxcrt/fx_string.h"
+#include "core/fxcrt/fx_system.h"
+
+class CPDF_Array;
+class CPDF_Boolean;
+class CPDF_Dictionary;
+class CPDF_Name;
+class CPDF_Null;
+class CPDF_Number;
+class CPDF_Reference;
+class CPDF_Stream;
+class CPDF_String;
+
+class CPDF_Object {
+ public:
+  static const uint32_t kInvalidObjNum = static_cast<uint32_t>(-1);
+  enum Type {
+    BOOLEAN = 1,
+    NUMBER,
+    STRING,
+    NAME,
+    ARRAY,
+    DICTIONARY,
+    STREAM,
+    NULLOBJ,
+    REFERENCE
+  };
+
+  virtual Type GetType() const = 0;
+  uint32_t GetObjNum() const { return m_ObjNum; }
+  uint32_t GetGenNum() const { return m_GenNum; }
+
+  // Create a deep copy of the object.
+  virtual CPDF_Object* Clone() const = 0;
+  // Create a deep copy of the object except any reference object be
+  // copied to the object it points to directly.
+  virtual CPDF_Object* CloneDirectObject() const;
+  virtual CPDF_Object* GetDirect() const;
+
+  void Release();
+
+  virtual CFX_ByteString GetString() const;
+  virtual CFX_WideString GetUnicodeText() const;
+  virtual FX_FLOAT GetNumber() const;
+  virtual int GetInteger() const;
+  virtual CPDF_Dictionary* GetDict() const;
+
+  virtual void SetString(const CFX_ByteString& str);
+
+  virtual bool IsArray() const;
+  virtual bool IsBoolean() const;
+  virtual bool IsDictionary() const;
+  virtual bool IsName() const;
+  virtual bool IsNumber() const;
+  virtual bool IsReference() const;
+  virtual bool IsStream() const;
+  virtual bool IsString() const;
+
+  virtual CPDF_Array* AsArray();
+  virtual const CPDF_Array* AsArray() const;
+  virtual CPDF_Boolean* AsBoolean();
+  virtual const CPDF_Boolean* AsBoolean() const;
+  virtual CPDF_Dictionary* AsDictionary();
+  virtual const CPDF_Dictionary* AsDictionary() const;
+  virtual CPDF_Name* AsName();
+  virtual const CPDF_Name* AsName() const;
+  virtual CPDF_Number* AsNumber();
+  virtual const CPDF_Number* AsNumber() const;
+  virtual CPDF_Reference* AsReference();
+  virtual const CPDF_Reference* AsReference() const;
+  virtual CPDF_Stream* AsStream();
+  virtual const CPDF_Stream* AsStream() const;
+  virtual CPDF_String* AsString();
+  virtual const CPDF_String* AsString() const;
+
+ protected:
+  friend class CPDF_Array;
+  friend class CPDF_Dictionary;
+  friend class CPDF_Document;
+  friend class CPDF_IndirectObjectHolder;
+  friend class CPDF_Parser;
+  friend class CPDF_Reference;
+  friend class CPDF_Stream;
+  friend struct std::default_delete<CPDF_Object>;
+
+  CPDF_Object() : m_ObjNum(0), m_GenNum(0) {}
+  virtual ~CPDF_Object();
+
+  CPDF_Object* CloneObjectNonCyclic(bool bDirect) const;
+
+  // Create a deep copy of the object with the option to either
+  // copy a reference object or directly copy the object it refers to
+  // when |bDirect| is true.
+  // Also check cyclic reference against |pVisited|, no copy if it is found.
+  // Complex objects should implement their own CloneNonCyclic()
+  // function to properly check for possible loop.
+  virtual CPDF_Object* CloneNonCyclic(
+      bool bDirect,
+      std::set<const CPDF_Object*>* pVisited) const;
+
+  uint32_t m_ObjNum;
+  uint32_t m_GenNum;
+
+ private:
+  CPDF_Object(const CPDF_Object& src) {}
+};
+
+inline CPDF_Boolean* ToBoolean(CPDF_Object* obj) {
+  return obj ? obj->AsBoolean() : nullptr;
+}
+
+inline const CPDF_Boolean* ToBoolean(const CPDF_Object* obj) {
+  return obj ? obj->AsBoolean() : nullptr;
+}
+
+inline CPDF_Number* ToNumber(CPDF_Object* obj) {
+  return obj ? obj->AsNumber() : nullptr;
+}
+
+inline const CPDF_Number* ToNumber(const CPDF_Object* obj) {
+  return obj ? obj->AsNumber() : nullptr;
+}
+
+inline CPDF_String* ToString(CPDF_Object* obj) {
+  return obj ? obj->AsString() : nullptr;
+}
+
+inline const CPDF_String* ToString(const CPDF_Object* obj) {
+  return obj ? obj->AsString() : nullptr;
+}
+
+inline CPDF_Name* ToName(CPDF_Object* obj) {
+  return obj ? obj->AsName() : nullptr;
+}
+
+inline const CPDF_Name* ToName(const CPDF_Object* obj) {
+  return obj ? obj->AsName() : nullptr;
+}
+
+inline CPDF_Array* ToArray(CPDF_Object* obj) {
+  return obj ? obj->AsArray() : nullptr;
+}
+
+inline const CPDF_Array* ToArray(const CPDF_Object* obj) {
+  return obj ? obj->AsArray() : nullptr;
+}
+
+inline CPDF_Dictionary* ToDictionary(CPDF_Object* obj) {
+  return obj ? obj->AsDictionary() : nullptr;
+}
+
+inline const CPDF_Dictionary* ToDictionary(const CPDF_Object* obj) {
+  return obj ? obj->AsDictionary() : nullptr;
+}
+inline CPDF_Reference* ToReference(CPDF_Object* obj) {
+  return obj ? obj->AsReference() : nullptr;
+}
+
+inline const CPDF_Reference* ToReference(const CPDF_Object* obj) {
+  return obj ? obj->AsReference() : nullptr;
+}
+
+inline CPDF_Stream* ToStream(CPDF_Object* obj) {
+  return obj ? obj->AsStream() : nullptr;
+}
+
+inline const CPDF_Stream* ToStream(const CPDF_Object* obj) {
+  return obj ? obj->AsStream() : nullptr;
+}
+
+#endif  // CORE_FPDFAPI_PARSER_CPDF_OBJECT_H_
diff --git a/core/fpdfapi/parser/cpdf_object_unittest.cpp b/core/fpdfapi/parser/cpdf_object_unittest.cpp
new file mode 100644
index 0000000000..b2177afd8a
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_object_unittest.cpp
@@ -0,0 +1,835 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "core/fpdfapi/parser/cpdf_array.h"
+#include "core/fpdfapi/parser/cpdf_boolean.h"
+#include "core/fpdfapi/parser/cpdf_dictionary.h"
+#include "core/fpdfapi/parser/cpdf_name.h"
+#include "core/fpdfapi/parser/cpdf_null.h"
+#include "core/fpdfapi/parser/cpdf_number.h"
+#include "core/fpdfapi/parser/cpdf_reference.h"
+#include "core/fpdfapi/parser/cpdf_stream.h"
+#include "core/fpdfapi/parser/cpdf_string.h"
+
+#include <memory>
+#include <string>
+#include <vector>
+
+#include "core/fpdfapi/parser/cpdf_indirect_object_holder.h"
+#include "core/fxcrt/fx_basic.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace {
+
+using ScopedArray = std::unique_ptr<CPDF_Array, ReleaseDeleter<CPDF_Array>>;
+using ScopedDict =
+    std::unique_ptr<CPDF_Dictionary, ReleaseDeleter<CPDF_Dictionary>>;
+
+void TestArrayAccessors(const CPDF_Array* arr,
+                        size_t index,
+                        const char* str_val,
+                        const char* const_str_val,
+                        int int_val,
+                        float float_val,
+                        CPDF_Array* arr_val,
+                        CPDF_Dictionary* dict_val,
+                        CPDF_Stream* stream_val) {
+  EXPECT_STREQ(str_val, arr->GetStringAt(index).c_str());
+  EXPECT_EQ(int_val, arr->GetIntegerAt(index));
+  EXPECT_EQ(float_val, arr->GetNumberAt(index));
+  EXPECT_EQ(float_val, arr->GetFloatAt(index));
+  EXPECT_EQ(arr_val, arr->GetArrayAt(index));
+  EXPECT_EQ(dict_val, arr->GetDictAt(index));
+  EXPECT_EQ(stream_val, arr->GetStreamAt(index));
+}
+
+}  // namespace
+
+class PDFObjectsTest : public testing::Test {
+ public:
+  void SetUp() override {
+    // Initialize different kinds of objects.
+    // Boolean objects.
+    CPDF_Boolean* boolean_false_obj = new CPDF_Boolean(false);
+    CPDF_Boolean* boolean_true_obj = new CPDF_Boolean(true);
+    // Number objects.
+    CPDF_Number* number_int_obj = new CPDF_Number(1245);
+    CPDF_Number* number_float_obj = new CPDF_Number(9.00345f);
+    // String objects.
+    CPDF_String* str_reg_obj = new CPDF_String(L"A simple test");
+    CPDF_String* str_spec_obj = new CPDF_String(L"\t\n");
+    // Name object.
+    CPDF_Name* name_obj = new CPDF_Name("space");
+    // Array object.
+    m_ArrayObj = new CPDF_Array;
+    m_ArrayObj->InsertAt(0, new CPDF_Number(8902));
+    m_ArrayObj->InsertAt(1, new CPDF_Name("address"));
+    // Dictionary object.
+    m_DictObj = new CPDF_Dictionary();
+    m_DictObj->SetFor("bool", new CPDF_Boolean(false));
+    m_DictObj->SetFor("num", new CPDF_Number(0.23f));
+    // Stream object.
+    const char content[] = "abcdefghijklmnopqrstuvwxyz";
+    size_t buf_len = FX_ArraySize(content);
+    uint8_t* buf = reinterpret_cast<uint8_t*>(malloc(buf_len));
+    memcpy(buf, content, buf_len);
+    m_StreamDictObj = new CPDF_Dictionary();
+    m_StreamDictObj->SetFor("key1", new CPDF_String(L" test dict"));
+    m_StreamDictObj->SetFor("key2", new CPDF_Number(-1));
+    CPDF_Stream* stream_obj = new CPDF_Stream(buf, buf_len, m_StreamDictObj);
+    // Null Object.
+    CPDF_Null* null_obj = new CPDF_Null;
+    // All direct objects.
+    CPDF_Object* objs[] = {boolean_false_obj, boolean_true_obj, number_int_obj,
+                           number_float_obj,  str_reg_obj,      str_spec_obj,
+                           name_obj,          m_ArrayObj,       m_DictObj,
+                           stream_obj,        null_obj};
+    m_DirectObjTypes = {
+        CPDF_Object::BOOLEAN, CPDF_Object::BOOLEAN, CPDF_Object::NUMBER,
+        CPDF_Object::NUMBER,  CPDF_Object::STRING,  CPDF_Object::STRING,
+        CPDF_Object::NAME,    CPDF_Object::ARRAY,   CPDF_Object::DICTIONARY,
+        CPDF_Object::STREAM,  CPDF_Object::NULLOBJ};
+    for (size_t i = 0; i < FX_ArraySize(objs); ++i)
+      m_DirectObjs.emplace_back(objs[i]);
+
+    // Indirect references to indirect objects.
+    m_ObjHolder.reset(new CPDF_IndirectObjectHolder());
+    m_IndirectObjs = {boolean_true_obj, number_int_obj, str_spec_obj, name_obj,
+                      m_ArrayObj,       m_DictObj,      stream_obj};
+    for (size_t i = 0; i < m_IndirectObjs.size(); ++i) {
+      m_ObjHolder->AddIndirectObject(m_IndirectObjs[i]);
+      m_RefObjs.emplace_back(new CPDF_Reference(
+          m_ObjHolder.get(), m_IndirectObjs[i]->GetObjNum()));
+    }
+  }
+
+  bool Equal(CPDF_Object* obj1, CPDF_Object* obj2) {
+    if (obj1 == obj2)
+      return true;
+    if (!obj1 || !obj2 || obj1->GetType() != obj2->GetType())
+      return false;
+    switch (obj1->GetType()) {
+      case CPDF_Object::BOOLEAN:
+        return obj1->GetInteger() == obj2->GetInteger();
+      case CPDF_Object::NUMBER:
+        return obj1->AsNumber()->IsInteger() == obj2->AsNumber()->IsInteger() &&
+               obj1->GetInteger() == obj2->GetInteger();
+      case CPDF_Object::STRING:
+      case CPDF_Object::NAME:
+        return obj1->GetString() == obj2->GetString();
+      case CPDF_Object::ARRAY: {
+        const CPDF_Array* array1 = obj1->AsArray();
+        const CPDF_Array* array2 = obj2->AsArray();
+        if (array1->GetCount() != array2->GetCount())
+          return false;
+        for (size_t i = 0; i < array1->GetCount(); ++i) {
+          if (!Equal(array1->GetObjectAt(i), array2->GetObjectAt(i)))
+            return false;
+        }
+        return true;
+      }
+      case CPDF_Object::DICTIONARY: {
+        const CPDF_Dictionary* dict1 = obj1->AsDictionary();
+        const CPDF_Dictionary* dict2 = obj2->AsDictionary();
+        if (dict1->GetCount() != dict2->GetCount())
+          return false;
+        for (CPDF_Dictionary::const_iterator it = dict1->begin();
+             it != dict1->end(); ++it) {
+          if (!Equal(it->second, dict2->GetObjectFor(it->first)))
+            return false;
+        }
+        return true;
+      }
+      case CPDF_Object::NULLOBJ:
+        return true;
+      case CPDF_Object::STREAM: {
+        const CPDF_Stream* stream1 = obj1->AsStream();
+        const CPDF_Stream* stream2 = obj2->AsStream();
+        if (!stream1->GetDict() && !stream2->GetDict())
+          return true;
+        // Compare dictionaries.
+        if (!Equal(stream1->GetDict(), stream2->GetDict()))
+          return false;
+        // Compare sizes.
+        if (stream1->GetRawSize() != stream2->GetRawSize())
+          return false;
+        // Compare contents.
+        // Since this function is used for testing Clone(), only memory based
+        // streams need to be handled.
+        if (!stream1->IsMemoryBased() || !stream2->IsMemoryBased())
+          return false;
+        return FXSYS_memcmp(stream1->GetRawData(), stream2->GetRawData(),
+                            stream1->GetRawSize()) == 0;
+      }
+      case CPDF_Object::REFERENCE:
+        return obj1->AsReference()->GetRefObjNum() ==
+               obj2->AsReference()->GetRefObjNum();
+    }
+    return false;
+  }
+
+ protected:
+  using ScopedObj = std::unique_ptr<CPDF_Object, ReleaseDeleter<CPDF_Object>>;
+
+  // m_ObjHolder needs to be declared first and destructed last since it also
+  // refers to some objects in m_DirectObjs.
+  std::unique_ptr<CPDF_IndirectObjectHolder> m_ObjHolder;
+  std::vector<ScopedObj> m_DirectObjs;
+  std::vector<int> m_DirectObjTypes;
+  std::vector<ScopedObj> m_RefObjs;
+  CPDF_Dictionary* m_DictObj;
+  CPDF_Dictionary* m_StreamDictObj;
+  CPDF_Array* m_ArrayObj;
+  std::vector<CPDF_Object*> m_IndirectObjs;
+};
+
+TEST_F(PDFObjectsTest, GetString) {
+  const char* const direct_obj_results[] = {
+      "false", "true", "1245", "9.00345", "A simple test", "\t\n", "space",
+      "",      "",     "",     ""};
+  // Check for direct objects.
+  for (size_t i = 0; i < m_DirectObjs.size(); ++i)
+    EXPECT_STREQ(direct_obj_results[i], m_DirectObjs[i]->GetString().c_str());
+
+  // Check indirect references.
+  const char* const indirect_obj_results[] = {"true", "1245", "\t\n", "space",
+                                              "",     "",     ""};
+  for (size_t i = 0; i < m_RefObjs.size(); ++i) {
+    EXPECT_STREQ(indirect_obj_results[i], m_RefObjs[i]->GetString().c_str());
+  }
+}
+
+TEST_F(PDFObjectsTest, GetUnicodeText) {
+  const wchar_t* const direct_obj_results[] = {
+      L"",     L"",      L"", L"", L"A simple test",
+      L"\t\n", L"space", L"", L"", L"abcdefghijklmnopqrstuvwxyz",
+      L""};
+  // Check for direct objects.
+  for (size_t i = 0; i < m_DirectObjs.size(); ++i) {
+    EXPECT_STREQ(direct_obj_results[i],
+                 m_DirectObjs[i]->GetUnicodeText().c_str());
+  }
+
+  // Check indirect references.
+  for (const auto& it : m_RefObjs)
+    EXPECT_STREQ(L"", it->GetUnicodeText().c_str());
+}
+
+TEST_F(PDFObjectsTest, GetNumber) {
+  const FX_FLOAT direct_obj_results[] = {0, 0, 1245, 9.00345f, 0, 0,
+                                         0, 0, 0,    0,        0};
+  // Check for direct objects.
+  for (size_t i = 0; i < m_DirectObjs.size(); ++i)
+    EXPECT_EQ(direct_obj_results[i], m_DirectObjs[i]->GetNumber());
+
+  // Check indirect references.
+  const FX_FLOAT indirect_obj_results[] = {0, 1245, 0, 0, 0, 0, 0};
+  for (size_t i = 0; i < m_RefObjs.size(); ++i)
+    EXPECT_EQ(indirect_obj_results[i], m_RefObjs[i]->GetNumber());
+}
+
+TEST_F(PDFObjectsTest, GetInteger) {
+  const int direct_obj_results[] = {0, 1, 1245, 9, 0, 0, 0, 0, 0, 0, 0};
+  // Check for direct objects.
+  for (size_t i = 0; i < m_DirectObjs.size(); ++i)
+    EXPECT_EQ(direct_obj_results[i], m_DirectObjs[i]->GetInteger());
+
+  // Check indirect references.
+  const int indirect_obj_results[] = {1, 1245, 0, 0, 0, 0, 0};
+  for (size_t i = 0; i < m_RefObjs.size(); ++i)
+    EXPECT_EQ(indirect_obj_results[i], m_RefObjs[i]->GetInteger());
+}
+
+TEST_F(PDFObjectsTest, GetDict) {
+  const CPDF_Dictionary* const direct_obj_results[] = {
+      nullptr, nullptr, nullptr,   nullptr,         nullptr, nullptr,
+      nullptr, nullptr, m_DictObj, m_StreamDictObj, nullptr};
+  // Check for direct objects.
+  for (size_t i = 0; i < m_DirectObjs.size(); ++i)
+    EXPECT_EQ(direct_obj_results[i], m_DirectObjs[i]->GetDict());
+
+  // Check indirect references.
+  const CPDF_Dictionary* const indirect_obj_results[] = {
+      nullptr, nullptr, nullptr, nullptr, nullptr, m_DictObj, m_StreamDictObj};
+  for (size_t i = 0; i < m_RefObjs.size(); ++i)
+    EXPECT_EQ(indirect_obj_results[i], m_RefObjs[i]->GetDict());
+}
+
+TEST_F(PDFObjectsTest, GetArray) {
+  const CPDF_Array* const direct_obj_results[] = {
+      nullptr, nullptr,    nullptr, nullptr, nullptr, nullptr,
+      nullptr, m_ArrayObj, nullptr, nullptr, nullptr};
+  // Check for direct objects.
+  for (size_t i = 0; i < m_DirectObjs.size(); ++i)
+    EXPECT_EQ(direct_obj_results[i], m_DirectObjs[i]->AsArray());
+
+  // Check indirect references.
+  for (const auto& it : m_RefObjs)
+    EXPECT_EQ(nullptr, it->AsArray());
+}
+
+TEST_F(PDFObjectsTest, Clone) {
+  // Check for direct objects.
+  for (size_t i = 0; i < m_DirectObjs.size(); ++i) {
+    ScopedObj obj(m_DirectObjs[i]->Clone());
+    EXPECT_TRUE(Equal(m_DirectObjs[i].get(), obj.get()));
+  }
+
+  // Check indirect references.
+  for (const auto& it : m_RefObjs) {
+    ScopedObj obj(it->Clone());
+    EXPECT_TRUE(Equal(it.get(), obj.get()));
+  }
+}
+
+TEST_F(PDFObjectsTest, GetType) {
+  // Check for direct objects.
+  for (size_t i = 0; i < m_DirectObjs.size(); ++i)
+    EXPECT_EQ(m_DirectObjTypes[i], m_DirectObjs[i]->GetType());
+
+  // Check indirect references.
+  for (const auto& it : m_RefObjs)
+    EXPECT_EQ(CPDF_Object::REFERENCE, it->GetType());
+}
+
+TEST_F(PDFObjectsTest, GetDirect) {
+  // Check for direct objects.
+  for (size_t i = 0; i < m_DirectObjs.size(); ++i)
+    EXPECT_EQ(m_DirectObjs[i].get(), m_DirectObjs[i]->GetDirect());
+
+  // Check indirect references.
+  for (size_t i = 0; i < m_RefObjs.size(); ++i)
+    EXPECT_EQ(m_IndirectObjs[i], m_RefObjs[i]->GetDirect());
+}
+
+TEST_F(PDFObjectsTest, SetString) {
+  // Check for direct objects.
+  const char* const set_values[] = {"true",    "fake", "3.125f", "097",
+                                    "changed", "",     "NewName"};
+  const char* const expected[] = {"true",    "false", "3.125",  "97",
+                                  "changed", "",      "NewName"};
+  for (size_t i = 0; i < FX_ArraySize(set_values); ++i) {
+    m_DirectObjs[i]->SetString(set_values[i]);
+    EXPECT_STREQ(expected[i], m_DirectObjs[i]->GetString().c_str());
+  }
+}
+
+TEST_F(PDFObjectsTest, IsTypeAndAsType) {
+  // Check for direct objects.
+  for (size_t i = 0; i < m_DirectObjs.size(); ++i) {
+    if (m_DirectObjTypes[i] == CPDF_Object::ARRAY) {
+      EXPECT_TRUE(m_DirectObjs[i]->IsArray());
+      EXPECT_EQ(m_DirectObjs[i].get(), m_DirectObjs[i]->AsArray());
+    } else {
+      EXPECT_FALSE(m_DirectObjs[i]->IsArray());
+      EXPECT_EQ(nullptr, m_DirectObjs[i]->AsArray());
+    }
+
+    if (m_DirectObjTypes[i] == CPDF_Object::BOOLEAN) {
+      EXPECT_TRUE(m_DirectObjs[i]->IsBoolean());
+      EXPECT_EQ(m_DirectObjs[i].get(), m_DirectObjs[i]->AsBoolean());
+    } else {
+      EXPECT_FALSE(m_DirectObjs[i]->IsBoolean());
+      EXPECT_EQ(nullptr, m_DirectObjs[i]->AsBoolean());
+    }
+
+    if (m_DirectObjTypes[i] == CPDF_Object::NAME) {
+      EXPECT_TRUE(m_DirectObjs[i]->IsName());
+      EXPECT_EQ(m_DirectObjs[i].get(), m_DirectObjs[i]->AsName());
+    } else {
+      EXPECT_FALSE(m_DirectObjs[i]->IsName());
+      EXPECT_EQ(nullptr, m_DirectObjs[i]->AsName());
+    }
+
+    if (m_DirectObjTypes[i] == CPDF_Object::NUMBER) {
+      EXPECT_TRUE(m_DirectObjs[i]->IsNumber());
+      EXPECT_EQ(m_DirectObjs[i].get(), m_DirectObjs[i]->AsNumber());
+    } else {
+      EXPECT_FALSE(m_DirectObjs[i]->IsNumber());
+      EXPECT_EQ(nullptr, m_DirectObjs[i]->AsNumber());
+    }
+
+    if (m_DirectObjTypes[i] == CPDF_Object::STRING) {
+      EXPECT_TRUE(m_DirectObjs[i]->IsString());
+      EXPECT_EQ(m_DirectObjs[i].get(), m_DirectObjs[i]->AsString());
+    } else {
+      EXPECT_FALSE(m_DirectObjs[i]->IsString());
+      EXPECT_EQ(nullptr, m_DirectObjs[i]->AsString());
+    }
+
+    if (m_DirectObjTypes[i] == CPDF_Object::DICTIONARY) {
+      EXPECT_TRUE(m_DirectObjs[i]->IsDictionary());
+      EXPECT_EQ(m_DirectObjs[i].get(), m_DirectObjs[i]->AsDictionary());
+    } else {
+      EXPECT_FALSE(m_DirectObjs[i]->IsDictionary());
+      EXPECT_EQ(nullptr, m_DirectObjs[i]->AsDictionary());
+    }
+
+    if (m_DirectObjTypes[i] == CPDF_Object::STREAM) {
+      EXPECT_TRUE(m_DirectObjs[i]->IsStream());
+      EXPECT_EQ(m_DirectObjs[i].get(), m_DirectObjs[i]->AsStream());
+    } else {
+      EXPECT_FALSE(m_DirectObjs[i]->IsStream());
+      EXPECT_EQ(nullptr, m_DirectObjs[i]->AsStream());
+    }
+
+    EXPECT_FALSE(m_DirectObjs[i]->IsReference());
+    EXPECT_EQ(nullptr, m_DirectObjs[i]->AsReference());
+  }
+  // Check indirect references.
+  for (size_t i = 0; i < m_RefObjs.size(); ++i) {
+    EXPECT_TRUE(m_RefObjs[i]->IsReference());
+    EXPECT_EQ(m_RefObjs[i].get(), m_RefObjs[i]->AsReference());
+  }
+}
+
+TEST(PDFArrayTest, GetMatrix) {
+  float elems[][6] = {{0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f},
+                      {1, 2, 3, 4, 5, 6},
+                      {2.3f, 4.05f, 3, -2, -3, 0.0f},
+                      {0.05f, 0.1f, 0.56f, 0.67f, 1.34f, 99.9f}};
+  for (size_t i = 0; i < FX_ArraySize(elems); ++i) {
+    ScopedArray arr(new CPDF_Array);
+    CFX_Matrix matrix(elems[i][0], elems[i][1], elems[i][2], elems[i][3],
+                      elems[i][4], elems[i][5]);
+    for (size_t j = 0; j < 6; ++j)
+      arr->AddNumber(elems[i][j]);
+    CFX_Matrix arr_matrix = arr->GetMatrix();
+    EXPECT_EQ(matrix.GetA(), arr_matrix.GetA());
+    EXPECT_EQ(matrix.GetB(), arr_matrix.GetB());
+    EXPECT_EQ(matrix.GetC(), arr_matrix.GetC());
+    EXPECT_EQ(matrix.GetD(), arr_matrix.GetD());
+    EXPECT_EQ(matrix.GetE(), arr_matrix.GetE());
+    EXPECT_EQ(matrix.GetF(), arr_matrix.GetF());
+  }
+}
+
+TEST(PDFArrayTest, GetRect) {
+  float elems[][4] = {{0.0f, 0.0f, 0.0f, 0.0f},
+                      {1, 2, 5, 6},
+                      {2.3f, 4.05f, -3, 0.0f},
+                      {0.05f, 0.1f, 1.34f, 99.9f}};
+  for (size_t i = 0; i < FX_ArraySize(elems); ++i) {
+    ScopedArray arr(new CPDF_Array);
+    CFX_FloatRect rect(elems[i]);
+    for (size_t j = 0; j < 4; ++j)
+      arr->AddNumber(elems[i][j]);
+    CFX_FloatRect arr_rect = arr->GetRect();
+    EXPECT_EQ(rect.left, arr_rect.left);
+    EXPECT_EQ(rect.right, arr_rect.right);
+    EXPECT_EQ(rect.bottom, arr_rect.bottom);
+    EXPECT_EQ(rect.top, arr_rect.top);
+  }
+}
+
+TEST(PDFArrayTest, GetTypeAt) {
+  {
+    // Boolean array.
+    const bool vals[] = {true, false, false, true, true};
+    ScopedArray arr(new CPDF_Array);
+    for (size_t i = 0; i < FX_ArraySize(vals); ++i)
+      arr->InsertAt(i, new CPDF_Boolean(vals[i]));
+    for (size_t i = 0; i < FX_ArraySize(vals); ++i) {
+      TestArrayAccessors(arr.get(), i,                // Array and index.
+                         vals[i] ? "true" : "false",  // String value.
+                         nullptr,                     // Const string value.
+                         vals[i] ? 1 : 0,             // Integer value.
+                         0,                           // Float value.
+                         nullptr,                     // Array value.
+                         nullptr,                     // Dictionary value.
+                         nullptr);                    // Stream value.
+    }
+  }
+  {
+    // Integer array.
+    const int vals[] = {10, 0, -345, 2089345456, -1000000000, 567, 93658767};
+    ScopedArray arr(new CPDF_Array);
+    for (size_t i = 0; i < FX_ArraySize(vals); ++i)
+      arr->InsertAt(i, new CPDF_Number(vals[i]));
+    for (size_t i = 0; i < FX_ArraySize(vals); ++i) {
+      char buf[33];
+      TestArrayAccessors(arr.get(), i,                  // Array and index.
+                         FXSYS_itoa(vals[i], buf, 10),  // String value.
+                         nullptr,                       // Const string value.
+                         vals[i],                       // Integer value.
+                         vals[i],                       // Float value.
+                         nullptr,                       // Array value.
+                         nullptr,                       // Dictionary value.
+                         nullptr);                      // Stream value.
+    }
+  }
+  {
+    // Float array.
+    const float vals[] = {0.0f,    0,     10,    10.0f,   0.0345f,
+                          897.34f, -2.5f, -1.0f, -345.0f, -0.0f};
+    const char* const expected_str[] = {
+        "0", "0", "10", "10", "0.0345", "897.34", "-2.5", "-1", "-345", "0"};
+    ScopedArray arr(new CPDF_Array);
+    for (size_t i = 0; i < FX_ArraySize(vals); ++i) {
+      arr->InsertAt(i, new CPDF_Number(vals[i]));
+    }
+    for (size_t i = 0; i < FX_ArraySize(vals); ++i) {
+      TestArrayAccessors(arr.get(), i,     // Array and index.
+                         expected_str[i],  // String value.
+                         nullptr,          // Const string value.
+                         vals[i],          // Integer value.
+                         vals[i],          // Float value.
+                         nullptr,          // Array value.
+                         nullptr,          // Dictionary value.
+                         nullptr);         // Stream value.
+    }
+  }
+  {
+    // String and name array
+    const char* const vals[] = {"this", "adsde$%^", "\r\t",           "\"012",
+                                ".",    "EYREW",    "It is a joke :)"};
+    ScopedArray string_array(new CPDF_Array);
+    ScopedArray name_array(new CPDF_Array);
+    for (size_t i = 0; i < FX_ArraySize(vals); ++i) {
+      string_array->InsertAt(i, new CPDF_String(vals[i], false));
+      name_array->InsertAt(i, new CPDF_Name(vals[i]));
+    }
+    for (size_t i = 0; i < FX_ArraySize(vals); ++i) {
+      TestArrayAccessors(string_array.get(), i,  // Array and index.
+                         vals[i],                // String value.
+                         vals[i],                // Const string value.
+                         0,                      // Integer value.
+                         0,                      // Float value.
+                         nullptr,                // Array value.
+                         nullptr,                // Dictionary value.
+                         nullptr);               // Stream value.
+      TestArrayAccessors(name_array.get(), i,    // Array and index.
+                         vals[i],                // String value.
+                         vals[i],                // Const string value.
+                         0,                      // Integer value.
+                         0,                      // Float value.
+                         nullptr,                // Array value.
+                         nullptr,                // Dictionary value.
+                         nullptr);               // Stream value.
+    }
+  }
+  {
+    // Null element array.
+    ScopedArray arr(new CPDF_Array);
+    for (size_t i = 0; i < 3; ++i)
+      arr->InsertAt(i, new CPDF_Null);
+    for (size_t i = 0; i < 3; ++i) {
+      TestArrayAccessors(arr.get(), i,  // Array and index.
+                         "",            // String value.
+                         nullptr,       // Const string value.
+                         0,             // Integer value.
+                         0,             // Float value.
+                         nullptr,       // Array value.
+                         nullptr,       // Dictionary value.
+                         nullptr);      // Stream value.
+    }
+  }
+  {
+    // Array of array.
+    CPDF_Array* vals[3];
+    ScopedArray arr(new CPDF_Array);
+    for (size_t i = 0; i < 3; ++i) {
+      vals[i] = new CPDF_Array;
+      for (size_t j = 0; j < 3; ++j) {
+        int value = j + 100;
+        vals[i]->InsertAt(i, new CPDF_Number(value));
+      }
+      arr->InsertAt(i, vals[i]);
+    }
+    for (size_t i = 0; i < 3; ++i) {
+      TestArrayAccessors(arr.get(), i,  // Array and index.
+                         "",            // String value.
+                         nullptr,       // Const string value.
+                         0,             // Integer value.
+                         0,             // Float value.
+                         vals[i],       // Array value.
+                         nullptr,       // Dictionary value.
+                         nullptr);      // Stream value.
+    }
+  }
+  {
+    // Dictionary array.
+    CPDF_Dictionary* vals[3];
+    ScopedArray arr(new CPDF_Array);
+    for (size_t i = 0; i < 3; ++i) {
+      vals[i] = new CPDF_Dictionary();
+      for (size_t j = 0; j < 3; ++j) {
+        std::string key("key");
+        char buf[33];
+        key.append(FXSYS_itoa(j, buf, 10));
+        int value = j + 200;
+        vals[i]->SetFor(key.c_str(), new CPDF_Number(value));
+      }
+      arr->InsertAt(i, vals[i]);
+    }
+    for (size_t i = 0; i < 3; ++i) {
+      TestArrayAccessors(arr.get(), i,  // Array and index.
+                         "",            // String value.
+                         nullptr,       // Const string value.
+                         0,             // Integer value.
+                         0,             // Float value.
+                         nullptr,       // Array value.
+                         vals[i],       // Dictionary value.
+                         nullptr);      // Stream value.
+    }
+  }
+  {
+    // Stream array.
+    CPDF_Dictionary* vals[3];
+    CPDF_Stream* stream_vals[3];
+    ScopedArray arr(new CPDF_Array);
+    for (size_t i = 0; i < 3; ++i) {
+      vals[i] = new CPDF_Dictionary();
+      for (size_t j = 0; j < 3; ++j) {
+        std::string key("key");
+        char buf[33];
+        key.append(FXSYS_itoa(j, buf, 10));
+        int value = j + 200;
+        vals[i]->SetFor(key.c_str(), new CPDF_Number(value));
+      }
+      uint8_t content[] = "content: this is a stream";
+      size_t data_size = FX_ArraySize(content);
+      uint8_t* data = reinterpret_cast<uint8_t*>(malloc(data_size));
+      memcpy(data, content, data_size);
+      stream_vals[i] = new CPDF_Stream(data, data_size, vals[i]);
+      arr->InsertAt(i, stream_vals[i]);
+    }
+    for (size_t i = 0; i < 3; ++i) {
+      TestArrayAccessors(arr.get(), i,     // Array and index.
+                         "",               // String value.
+                         nullptr,          // Const string value.
+                         0,                // Integer value.
+                         0,                // Float value.
+                         nullptr,          // Array value.
+                         vals[i],          // Dictionary value.
+                         stream_vals[i]);  // Stream value.
+    }
+  }
+  {
+    // Mixed array.
+    ScopedArray arr(new CPDF_Array);
+    // Array arr will take ownership of all the objects inserted.
+    arr->InsertAt(0, new CPDF_Boolean(true));
+    arr->InsertAt(1, new CPDF_Boolean(false));
+    arr->InsertAt(2, new CPDF_Number(0));
+    arr->InsertAt(3, new CPDF_Number(-1234));
+    arr->InsertAt(4, new CPDF_Number(2345.0f));
+    arr->InsertAt(5, new CPDF_Number(0.05f));
+    arr->InsertAt(6, new CPDF_String("", false));
+    arr->InsertAt(7, new CPDF_String("It is a test!", false));
+    arr->InsertAt(8, new CPDF_Name("NAME"));
+    arr->InsertAt(9, new CPDF_Name("test"));
+    arr->InsertAt(10, new CPDF_Null());
+    CPDF_Array* arr_val = new CPDF_Array;
+    arr_val->AddNumber(1);
+    arr_val->AddNumber(2);
+    arr->InsertAt(11, arr_val);
+    CPDF_Dictionary* dict_val = new CPDF_Dictionary();
+    dict_val->SetFor("key1", new CPDF_String("Linda", false));
+    dict_val->SetFor("key2", new CPDF_String("Zoe", false));
+    arr->InsertAt(12, dict_val);
+    CPDF_Dictionary* stream_dict = new CPDF_Dictionary();
+    stream_dict->SetFor("key1", new CPDF_String("John", false));
+    stream_dict->SetFor("key2", new CPDF_String("King", false));
+    uint8_t data[] = "A stream for test";
+    // The data buffer will be owned by stream object, so it needs to be
+    // dynamically allocated.
+    size_t buf_size = sizeof(data);
+    uint8_t* buf = reinterpret_cast<uint8_t*>(malloc(buf_size));
+    memcpy(buf, data, buf_size);
+    CPDF_Stream* stream_val = new CPDF_Stream(buf, buf_size, stream_dict);
+    arr->InsertAt(13, stream_val);
+    const char* const expected_str[] = {
+        "true",          "false", "0",    "-1234", "2345", "0.05", "",
+        "It is a test!", "NAME",  "test", "",      "",     "",     ""};
+    const int expected_int[] = {1, 0, 0, -1234, 2345, 0, 0,
+                                0, 0, 0, 0,     0,    0, 0};
+    const float expected_float[] = {0, 0, 0, -1234, 2345, 0.05f, 0,
+                                    0, 0, 0, 0,     0,    0,     0};
+    for (size_t i = 0; i < arr->GetCount(); ++i) {
+      EXPECT_STREQ(expected_str[i], arr->GetStringAt(i).c_str());
+      EXPECT_EQ(expected_int[i], arr->GetIntegerAt(i));
+      EXPECT_EQ(expected_float[i], arr->GetNumberAt(i));
+      EXPECT_EQ(expected_float[i], arr->GetFloatAt(i));
+      if (i == 11)
+        EXPECT_EQ(arr_val, arr->GetArrayAt(i));
+      else
+        EXPECT_EQ(nullptr, arr->GetArrayAt(i));
+      if (i == 13) {
+        EXPECT_EQ(stream_dict, arr->GetDictAt(i));
+        EXPECT_EQ(stream_val, arr->GetStreamAt(i));
+      } else {
+        EXPECT_EQ(nullptr, arr->GetStreamAt(i));
+        if (i == 12)
+          EXPECT_EQ(dict_val, arr->GetDictAt(i));
+        else
+          EXPECT_EQ(nullptr, arr->GetDictAt(i));
+      }
+    }
+  }
+}
+
+TEST(PDFArrayTest, AddNumber) {
+  float vals[] = {1.0f,         -1.0f, 0,    0.456734f,
+                  12345.54321f, 0.5f,  1000, 0.000045f};
+  ScopedArray arr(new CPDF_Array);
+  for (size_t i = 0; i < FX_ArraySize(vals); ++i)
+    arr->AddNumber(vals[i]);
+  for (size_t i = 0; i < FX_ArraySize(vals); ++i) {
+    EXPECT_EQ(CPDF_Object::NUMBER, arr->GetObjectAt(i)->GetType());
+    EXPECT_EQ(vals[i], arr->GetObjectAt(i)->GetNumber());
+  }
+}
+
+TEST(PDFArrayTest, AddInteger) {
+  int vals[] = {0, 1, 934435456, 876, 10000, -1, -24354656, -100};
+  ScopedArray arr(new CPDF_Array);
+  for (size_t i = 0; i < FX_ArraySize(vals); ++i)
+    arr->AddInteger(vals[i]);
+  for (size_t i = 0; i < FX_ArraySize(vals); ++i) {
+    EXPECT_EQ(CPDF_Object::NUMBER, arr->GetObjectAt(i)->GetType());
+    EXPECT_EQ(vals[i], arr->GetObjectAt(i)->GetNumber());
+  }
+}
+
+TEST(PDFArrayTest, AddStringAndName) {
+  const char* vals[] = {"",        "a", "ehjhRIOYTTFdfcdnv",  "122323",
+                        "$#%^&**", " ", "This is a test.\r\n"};
+  ScopedArray string_array(new CPDF_Array);
+  ScopedArray name_array(new CPDF_Array);
+  for (size_t i = 0; i < FX_ArraySize(vals); ++i) {
+    string_array->AddString(vals[i]);
+    name_array->AddName(vals[i]);
+  }
+  for (size_t i = 0; i < FX_ArraySize(vals); ++i) {
+    EXPECT_EQ(CPDF_Object::STRING, string_array->GetObjectAt(i)->GetType());
+    EXPECT_STREQ(vals[i], string_array->GetObjectAt(i)->GetString().c_str());
+    EXPECT_EQ(CPDF_Object::NAME, name_array->GetObjectAt(i)->GetType());
+    EXPECT_STREQ(vals[i], name_array->GetObjectAt(i)->GetString().c_str());
+  }
+}
+
+TEST(PDFArrayTest, AddReferenceAndGetObjectAt) {
+  std::unique_ptr<CPDF_IndirectObjectHolder> holder(
+      new CPDF_IndirectObjectHolder());
+  CPDF_Boolean* boolean_obj = new CPDF_Boolean(true);
+  CPDF_Number* int_obj = new CPDF_Number(-1234);
+  CPDF_Number* float_obj = new CPDF_Number(2345.089f);
+  CPDF_String* str_obj = new CPDF_String("Adsfdsf 343434 %&&*\n", false);
+  CPDF_Name* name_obj = new CPDF_Name("Title:");
+  CPDF_Null* null_obj = new CPDF_Null();
+  CPDF_Object* indirect_objs[] = {boolean_obj, int_obj,  float_obj,
+                                  str_obj,     name_obj, null_obj};
+  unsigned int obj_nums[] = {2, 4, 7, 2345, 799887, 1};
+  ScopedArray arr(new CPDF_Array);
+  ScopedArray arr1(new CPDF_Array);
+  // Create two arrays of references by different AddReference() APIs.
+  for (size_t i = 0; i < FX_ArraySize(indirect_objs); ++i) {
+    // All the indirect objects inserted will be owned by holder.
+    holder->ReplaceIndirectObjectIfHigherGeneration(obj_nums[i],
+                                                    indirect_objs[i]);
+    arr->AddReference(holder.get(), obj_nums[i]);
+    arr1->AddReference(holder.get(), indirect_objs[i]->GetObjNum());
+  }
+  // Check indirect objects.
+  for (size_t i = 0; i < FX_ArraySize(obj_nums); ++i)
+    EXPECT_EQ(indirect_objs[i], holder->GetOrParseIndirectObject(obj_nums[i]));
+  // Check arrays.
+  EXPECT_EQ(arr->GetCount(), arr1->GetCount());
+  for (size_t i = 0; i < arr->GetCount(); ++i) {
+    EXPECT_EQ(CPDF_Object::REFERENCE, arr->GetObjectAt(i)->GetType());
+    EXPECT_EQ(indirect_objs[i], arr->GetObjectAt(i)->GetDirect());
+    EXPECT_EQ(indirect_objs[i], arr->GetDirectObjectAt(i));
+    EXPECT_EQ(CPDF_Object::REFERENCE, arr1->GetObjectAt(i)->GetType());
+    EXPECT_EQ(indirect_objs[i], arr1->GetObjectAt(i)->GetDirect());
+    EXPECT_EQ(indirect_objs[i], arr1->GetDirectObjectAt(i));
+  }
+}
+
+TEST(PDFArrayTest, CloneDirectObject) {
+  CPDF_IndirectObjectHolder objects_holder;
+  ScopedArray array(new CPDF_Array);
+  array->AddReference(&objects_holder, 1234);
+  ASSERT_EQ(1U, array->GetCount());
+  CPDF_Object* obj = array->GetObjectAt(0);
+  ASSERT_TRUE(obj);
+  EXPECT_TRUE(obj->IsReference());
+
+  CPDF_Object* cloned_array_object = array->CloneDirectObject();
+  ASSERT_TRUE(cloned_array_object);
+  ASSERT_TRUE(cloned_array_object->IsArray());
+
+  ScopedArray cloned_array(cloned_array_object->AsArray());
+  ASSERT_EQ(1U, cloned_array->GetCount());
+  CPDF_Object* cloned_obj = cloned_array->GetObjectAt(0);
+  EXPECT_FALSE(cloned_obj);
+}
+
+TEST(PDFDictionaryTest, CloneDirectObject) {
+  CPDF_IndirectObjectHolder objects_holder;
+  ScopedDict dict(new CPDF_Dictionary());
+  dict->SetReferenceFor("foo", &objects_holder, 1234);
+  ASSERT_EQ(1U, dict->GetCount());
+  CPDF_Object* obj = dict->GetObjectFor("foo");
+  ASSERT_TRUE(obj);
+  EXPECT_TRUE(obj->IsReference());
+
+  CPDF_Object* cloned_dict_object = dict->CloneDirectObject();
+  ASSERT_TRUE(cloned_dict_object);
+  ASSERT_TRUE(cloned_dict_object->IsDictionary());
+
+  ScopedDict cloned_dict(cloned_dict_object->AsDictionary());
+  ASSERT_EQ(1U, cloned_dict->GetCount());
+  CPDF_Object* cloned_obj = cloned_dict->GetObjectFor("foo");
+  EXPECT_FALSE(cloned_obj);
+}
+
+TEST(PDFObjectTest, CloneCheckLoop) {
+  {
+    // Create an object with a reference loop.
+    ScopedArray arr_obj(new CPDF_Array);
+    // Dictionary object.
+    CPDF_Dictionary* dict_obj = new CPDF_Dictionary();
+    dict_obj->SetFor("arr", arr_obj.get());
+    arr_obj->InsertAt(0, dict_obj);
+
+    // Clone this object to see whether stack overflow will be triggered.
+    ScopedArray cloned_array(arr_obj->Clone()->AsArray());
+    // Cloned object should be the same as the original.
+    ASSERT_TRUE(cloned_array);
+    EXPECT_EQ(1u, cloned_array->GetCount());
+    CPDF_Object* cloned_dict = cloned_array->GetObjectAt(0);
+    ASSERT_TRUE(cloned_dict);
+    ASSERT_TRUE(cloned_dict->IsDictionary());
+    // Recursively referenced object is not cloned.
+    EXPECT_EQ(nullptr, cloned_dict->AsDictionary()->GetObjectFor("arr"));
+  }
+  {
+    CPDF_IndirectObjectHolder objects_holder;
+    // Create an object with a reference loop.
+    CPDF_Dictionary* dict_obj = new CPDF_Dictionary();
+    CPDF_Array* arr_obj = new CPDF_Array;
+    objects_holder.AddIndirectObject(dict_obj);
+    EXPECT_EQ(1u, dict_obj->GetObjNum());
+    dict_obj->SetFor("arr", arr_obj);
+    arr_obj->InsertAt(
+        0, new CPDF_Reference(&objects_holder, dict_obj->GetObjNum()));
+    CPDF_Object* elem0 = arr_obj->GetObjectAt(0);
+    ASSERT_TRUE(elem0);
+    ASSERT_TRUE(elem0->IsReference());
+    EXPECT_EQ(1u, elem0->AsReference()->GetRefObjNum());
+    EXPECT_EQ(dict_obj, elem0->AsReference()->GetDirect());
+
+    // Clone this object to see whether stack overflow will be triggered.
+    ScopedDict cloned_dict(ToDictionary(dict_obj->CloneDirectObject()));
+    // Cloned object should be the same as the original.
+    ASSERT_TRUE(cloned_dict);
+    CPDF_Object* cloned_arr = cloned_dict->GetObjectFor("arr");
+    ASSERT_TRUE(cloned_arr);
+    ASSERT_TRUE(cloned_arr->IsArray());
+    EXPECT_EQ(1u, cloned_arr->AsArray()->GetCount());
+    // Recursively referenced object is not cloned.
+    EXPECT_EQ(nullptr, cloned_arr->AsArray()->GetObjectAt(0));
+  }
+}
diff --git a/core/fpdfapi/parser/cpdf_parser.cpp b/core/fpdfapi/parser/cpdf_parser.cpp
new file mode 100644
index 0000000000..17539101a1
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_parser.cpp
@@ -0,0 +1,1637 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#include "core/fpdfapi/parser/cpdf_parser.h"
+
+#include <vector>
+
+#include "core/fpdfapi/parser/cpdf_array.h"
+#include "core/fpdfapi/parser/cpdf_crypto_handler.h"
+#include "core/fpdfapi/parser/cpdf_dictionary.h"
+#include "core/fpdfapi/parser/cpdf_document.h"
+#include "core/fpdfapi/parser/cpdf_number.h"
+#include "core/fpdfapi/parser/cpdf_reference.h"
+#include "core/fpdfapi/parser/cpdf_security_handler.h"
+#include "core/fpdfapi/parser/cpdf_stream.h"
+#include "core/fpdfapi/parser/cpdf_stream_acc.h"
+#include "core/fpdfapi/parser/cpdf_syntax_parser.h"
+#include "core/fpdfapi/parser/fpdf_parser_utility.h"
+#include "core/fxcrt/fx_ext.h"
+#include "core/fxcrt/fx_safe_types.h"
+#include "third_party/base/stl_util.h"
+
+namespace {
+
+// A limit on the size of the xref table. Theoretical limits are higher, but
+// this may be large enough in practice.
+const int32_t kMaxXRefSize = 1048576;
+
+uint32_t GetVarInt(const uint8_t* p, int32_t n) {
+  uint32_t result = 0;
+  for (int32_t i = 0; i < n; ++i)
+    result = result * 256 + p[i];
+  return result;
+}
+
+int32_t GetStreamNCount(CPDF_StreamAcc* pObjStream) {
+  return pObjStream->GetDict()->GetIntegerFor("N");
+}
+
+int32_t GetStreamFirst(CPDF_StreamAcc* pObjStream) {
+  return pObjStream->GetDict()->GetIntegerFor("First");
+}
+
+}  // namespace
+
+CPDF_Parser::CPDF_Parser()
+    : m_pDocument(nullptr),
+      m_bHasParsed(false),
+      m_bOwnFileRead(true),
+      m_FileVersion(0),
+      m_pTrailer(nullptr),
+      m_pEncryptDict(nullptr),
+      m_bVersionUpdated(false),
+      m_pLinearized(nullptr),
+      m_dwFirstPageNo(0),
+      m_dwXrefStartObjNum(0) {
+  m_pSyntax.reset(new CPDF_SyntaxParser);
+}
+
+CPDF_Parser::~CPDF_Parser() {
+  if (m_pTrailer)
+    m_pTrailer->Release();
+
+  ReleaseEncryptHandler();
+  SetEncryptDictionary(nullptr);
+
+  if (m_bOwnFileRead && m_pSyntax->m_pFileAccess) {
+    m_pSyntax->m_pFileAccess->Release();
+    m_pSyntax->m_pFileAccess = nullptr;
+  }
+
+  int32_t iLen = m_Trailers.GetSize();
+  for (int32_t i = 0; i < iLen; ++i) {
+    if (CPDF_Dictionary* trailer = m_Trailers.GetAt(i))
+      trailer->Release();
+  }
+
+  if (m_pLinearized)
+    m_pLinearized->Release();
+}
+
+uint32_t CPDF_Parser::GetLastObjNum() const {
+  return m_ObjectInfo.empty() ? 0 : m_ObjectInfo.rbegin()->first;
+}
+
+bool CPDF_Parser::IsValidObjectNumber(uint32_t objnum) const {
+  return !m_ObjectInfo.empty() && objnum <= m_ObjectInfo.rbegin()->first;
+}
+
+FX_FILESIZE CPDF_Parser::GetObjectPositionOrZero(uint32_t objnum) const {
+  auto it = m_ObjectInfo.find(objnum);
+  return it != m_ObjectInfo.end() ? it->second.pos : 0;
+}
+
+uint8_t CPDF_Parser::GetObjectType(uint32_t objnum) const {
+  ASSERT(IsValidObjectNumber(objnum));
+  auto it = m_ObjectInfo.find(objnum);
+  return it != m_ObjectInfo.end() ? it->second.type : 0;
+}
+
+uint16_t CPDF_Parser::GetObjectGenNum(uint32_t objnum) const {
+  ASSERT(IsValidObjectNumber(objnum));
+  auto it = m_ObjectInfo.find(objnum);
+  return it != m_ObjectInfo.end() ? it->second.gennum : 0;
+}
+
+bool CPDF_Parser::IsObjectFreeOrNull(uint32_t objnum) const {
+  uint8_t type = GetObjectType(objnum);
+  return type == 0 || type == 255;
+}
+
+void CPDF_Parser::SetEncryptDictionary(CPDF_Dictionary* pDict) {
+  m_pEncryptDict = pDict;
+}
+
+CPDF_CryptoHandler* CPDF_Parser::GetCryptoHandler() {
+  return m_pSyntax->m_pCryptoHandler.get();
+}
+
+IFX_FileRead* CPDF_Parser::GetFileAccess() const {
+  return m_pSyntax->m_pFileAccess;
+}
+
+void CPDF_Parser::ShrinkObjectMap(uint32_t objnum) {
+  if (objnum == 0) {
+    m_ObjectInfo.clear();
+    return;
+  }
+
+  auto it = m_ObjectInfo.lower_bound(objnum);
+  while (it != m_ObjectInfo.end()) {
+    auto saved_it = it++;
+    m_ObjectInfo.erase(saved_it);
+  }
+
+  if (!pdfium::ContainsKey(m_ObjectInfo, objnum - 1))
+    m_ObjectInfo[objnum - 1].pos = 0;
+}
+
+CPDF_Parser::Error CPDF_Parser::StartParse(IFX_FileRead* pFileAccess,
+                                           CPDF_Document* pDocument) {
+  ASSERT(!m_bHasParsed);
+  m_bHasParsed = true;
+
+  m_bXRefStream = FALSE;
+  m_LastXRefOffset = 0;
+  m_bOwnFileRead = true;
+
+  int32_t offset = GetHeaderOffset(pFileAccess);
+  if (offset == -1) {
+    if (pFileAccess)
+      pFileAccess->Release();
+    return FORMAT_ERROR;
+  }
+  m_pSyntax->InitParser(pFileAccess, offset);
+
+  uint8_t ch;
+  if (!m_pSyntax->GetCharAt(5, ch))
+    return FORMAT_ERROR;
+  if (std::isdigit(ch))
+    m_FileVersion = FXSYS_toDecimalDigit(static_cast<FX_WCHAR>(ch)) * 10;
+
+  if (!m_pSyntax->GetCharAt(7, ch))
+    return FORMAT_ERROR;
+  if (std::isdigit(ch))
+    m_FileVersion += FXSYS_toDecimalDigit(static_cast<FX_WCHAR>(ch));
+
+  if (m_pSyntax->m_FileLen < m_pSyntax->m_HeaderOffset + 9)
+    return FORMAT_ERROR;
+
+  m_pSyntax->RestorePos(m_pSyntax->m_FileLen - m_pSyntax->m_HeaderOffset - 9);
+  m_pDocument = pDocument;
+
+  FX_BOOL bXRefRebuilt = FALSE;
+  if (m_pSyntax->SearchWord("startxref", TRUE, FALSE, 4096)) {
+    m_SortedOffset.insert(m_pSyntax->SavePos());
+    m_pSyntax->GetKeyword();
+
+    bool bNumber;
+    CFX_ByteString xrefpos_str = m_pSyntax->GetNextWord(&bNumber);
+    if (!bNumber)
+      return FORMAT_ERROR;
+
+    m_LastXRefOffset = (FX_FILESIZE)FXSYS_atoi64(xrefpos_str.c_str());
+    if (!LoadAllCrossRefV4(m_LastXRefOffset) &&
+        !LoadAllCrossRefV5(m_LastXRefOffset)) {
+      if (!RebuildCrossRef())
+        return FORMAT_ERROR;
+
+      bXRefRebuilt = TRUE;
+      m_LastXRefOffset = 0;
+    }
+  } else {
+    if (!RebuildCrossRef())
+      return FORMAT_ERROR;
+
+    bXRefRebuilt = TRUE;
+  }
+  Error eRet = SetEncryptHandler();
+  if (eRet != SUCCESS)
+    return eRet;
+
+  m_pDocument->LoadDoc();
+  if (!m_pDocument->GetRoot() || m_pDocument->GetPageCount() == 0) {
+    if (bXRefRebuilt)
+      return FORMAT_ERROR;
+
+    ReleaseEncryptHandler();
+    if (!RebuildCrossRef())
+      return FORMAT_ERROR;
+
+    eRet = SetEncryptHandler();
+    if (eRet != SUCCESS)
+      return eRet;
+
+    m_pDocument->LoadDoc();
+    if (!m_pDocument->GetRoot())
+      return FORMAT_ERROR;
+  }
+  if (GetRootObjNum() == 0) {
+    ReleaseEncryptHandler();
+    if (!RebuildCrossRef() || GetRootObjNum() == 0)
+      return FORMAT_ERROR;
+
+    eRet = SetEncryptHandler();
+    if (eRet != SUCCESS)
+      return eRet;
+  }
+  if (m_pSecurityHandler && !m_pSecurityHandler->IsMetadataEncrypted()) {
+    CPDF_Reference* pMetadata =
+        ToReference(m_pDocument->GetRoot()->GetObjectFor("Metadata"));
+    if (pMetadata)
+      m_pSyntax->m_MetadataObjnum = pMetadata->GetRefObjNum();
+  }
+  return SUCCESS;
+}
+CPDF_Parser::Error CPDF_Parser::SetEncryptHandler() {
+  ReleaseEncryptHandler();
+  SetEncryptDictionary(nullptr);
+
+  if (!m_pTrailer)
+    return FORMAT_ERROR;
+
+  CPDF_Object* pEncryptObj = m_pTrailer->GetObjectFor("Encrypt");
+  if (pEncryptObj) {
+    if (CPDF_Dictionary* pEncryptDict = pEncryptObj->AsDictionary()) {
+      SetEncryptDictionary(pEncryptDict);
+    } else if (CPDF_Reference* pRef = pEncryptObj->AsReference()) {
+      pEncryptObj = m_pDocument->GetOrParseIndirectObject(pRef->GetRefObjNum());
+      if (pEncryptObj)
+        SetEncryptDictionary(pEncryptObj->GetDict());
+    }
+  }
+
+  if (m_pEncryptDict) {
+    CFX_ByteString filter = m_pEncryptDict->GetStringFor("Filter");
+    std::unique_ptr<CPDF_SecurityHandler> pSecurityHandler;
+    Error err = HANDLER_ERROR;
+    if (filter == "Standard") {
+      pSecurityHandler.reset(new CPDF_SecurityHandler);
+      err = PASSWORD_ERROR;
+    }
+    if (!pSecurityHandler)
+      return HANDLER_ERROR;
+
+    if (!pSecurityHandler->OnInit(this, m_pEncryptDict))
+      return err;
+
+    m_pSecurityHandler = std::move(pSecurityHandler);
+    std::unique_ptr<CPDF_CryptoHandler> pCryptoHandler(
+        m_pSecurityHandler->CreateCryptoHandler());
+    if (!pCryptoHandler->Init(m_pEncryptDict, m_pSecurityHandler.get()))
+      return HANDLER_ERROR;
+    m_pSyntax->SetEncrypt(std::move(pCryptoHandler));
+  }
+  return SUCCESS;
+}
+
+void CPDF_Parser::ReleaseEncryptHandler() {
+  m_pSyntax->m_pCryptoHandler.reset();
+  m_pSecurityHandler.reset();
+}
+
+FX_FILESIZE CPDF_Parser::GetObjectOffset(uint32_t objnum) const {
+  if (!IsValidObjectNumber(objnum))
+    return 0;
+
+  if (GetObjectType(objnum) == 1)
+    return GetObjectPositionOrZero(objnum);
+
+  if (GetObjectType(objnum) == 2) {
+    FX_FILESIZE pos = GetObjectPositionOrZero(objnum);
+    return GetObjectPositionOrZero(pos);
+  }
+  return 0;
+}
+
+// Ideally, all the cross reference entries should be verified.
+// In reality, we rarely see well-formed cross references don't match
+// with the objects. crbug/602650 showed a case where object numbers
+// in the cross reference table are all off by one.
+bool CPDF_Parser::VerifyCrossRefV4() {
+  for (const auto& it : m_ObjectInfo) {
+    if (it.second.pos == 0)
+      continue;
+    // Find the first non-zero position.
+    FX_FILESIZE SavedPos = m_pSyntax->SavePos();
+    m_pSyntax->RestorePos(it.second.pos);
+    bool is_num = false;
+    CFX_ByteString num_str = m_pSyntax->GetNextWord(&is_num);
+    m_pSyntax->RestorePos(SavedPos);
+    if (!is_num || num_str.IsEmpty() ||
+        FXSYS_atoui(num_str.c_str()) != it.first) {
+      // If the object number read doesn't match the one stored,
+      // something is wrong with the cross reference table.
+      return false;
+    } else {
+      return true;
+    }
+  }
+  return true;
+}
+
+FX_BOOL CPDF_Parser::LoadAllCrossRefV4(FX_FILESIZE xrefpos) {
+  if (!LoadCrossRefV4(xrefpos, 0, TRUE))
+    return FALSE;
+
+  m_pTrailer = LoadTrailerV4();
+  if (!m_pTrailer)
+    return FALSE;
+
+  int32_t xrefsize = GetDirectInteger(m_pTrailer, "Size");
+  if (xrefsize > 0 && xrefsize <= kMaxXRefSize)
+    ShrinkObjectMap(xrefsize);
+
+  std::vector<FX_FILESIZE> CrossRefList;
+  std::vector<FX_FILESIZE> XRefStreamList;
+  std::set<FX_FILESIZE> seen_xrefpos;
+
+  CrossRefList.push_back(xrefpos);
+  XRefStreamList.push_back(GetDirectInteger(m_pTrailer, "XRefStm"));
+  seen_xrefpos.insert(xrefpos);
+
+  // When |m_pTrailer| doesn't have Prev entry or Prev entry value is not
+  // numerical, GetDirectInteger() returns 0. Loading will end.
+  xrefpos = GetDirectInteger(m_pTrailer, "Prev");
+  while (xrefpos) {
+    // Check for circular references.
+    if (pdfium::ContainsKey(seen_xrefpos, xrefpos))
+      return FALSE;
+
+    seen_xrefpos.insert(xrefpos);
+
+    // SLOW ...
+    CrossRefList.insert(CrossRefList.begin(), xrefpos);
+    LoadCrossRefV4(xrefpos, 0, TRUE);
+
+    std::unique_ptr<CPDF_Dictionary, ReleaseDeleter<CPDF_Dictionary>> pDict(
+        LoadTrailerV4());
+    if (!pDict)
+      return FALSE;
+
+    xrefpos = GetDirectInteger(pDict.get(), "Prev");
+
+    // SLOW ...
+    XRefStreamList.insert(XRefStreamList.begin(),
+                          pDict->GetIntegerFor("XRefStm"));
+    m_Trailers.Add(pDict.release());
+  }
+
+  for (size_t i = 0; i < CrossRefList.size(); ++i) {
+    if (!LoadCrossRefV4(CrossRefList[i], XRefStreamList[i], FALSE))
+      return FALSE;
+    if (i == 0 && !VerifyCrossRefV4())
+      return FALSE;
+  }
+  return TRUE;
+}
+
+FX_BOOL CPDF_Parser::LoadLinearizedAllCrossRefV4(FX_FILESIZE xrefpos,
+                                                 uint32_t dwObjCount) {
+  if (!LoadLinearizedCrossRefV4(xrefpos, dwObjCount))
+    return FALSE;
+
+  m_pTrailer = LoadTrailerV4();
+  if (!m_pTrailer)
+    return FALSE;
+
+  int32_t xrefsize = GetDirectInteger(m_pTrailer, "Size");
+  if (xrefsize == 0)
+    return FALSE;
+
+  std::vector<FX_FILESIZE> CrossRefList;
+  std::vector<FX_FILESIZE> XRefStreamList;
+  std::set<FX_FILESIZE> seen_xrefpos;
+
+  CrossRefList.push_back(xrefpos);
+  XRefStreamList.push_back(GetDirectInteger(m_pTrailer, "XRefStm"));
+  seen_xrefpos.insert(xrefpos);
+
+  xrefpos = GetDirectInteger(m_pTrailer, "Prev");
+  while (xrefpos) {
+    // Check for circular references.
+    if (pdfium::ContainsKey(seen_xrefpos, xrefpos))
+      return FALSE;
+
+    seen_xrefpos.insert(xrefpos);
+
+    // SLOW ...
+    CrossRefList.insert(CrossRefList.begin(), xrefpos);
+    LoadCrossRefV4(xrefpos, 0, TRUE);
+
+    std::unique_ptr<CPDF_Dictionary, ReleaseDeleter<CPDF_Dictionary>> pDict(
+        LoadTrailerV4());
+    if (!pDict)
+      return FALSE;
+
+    xrefpos = GetDirectInteger(pDict.get(), "Prev");
+
+    // SLOW ...
+    XRefStreamList.insert(XRefStreamList.begin(),
+                          pDict->GetIntegerFor("XRefStm"));
+    m_Trailers.Add(pDict.release());
+  }
+
+  for (size_t i = 1; i < CrossRefList.size(); ++i) {
+    if (!LoadCrossRefV4(CrossRefList[i], XRefStreamList[i], FALSE))
+      return FALSE;
+  }
+  return TRUE;
+}
+
+FX_BOOL CPDF_Parser::LoadLinearizedCrossRefV4(FX_FILESIZE pos,
+                                              uint32_t dwObjCount) {
+  FX_FILESIZE dwStartPos = pos - m_pSyntax->m_HeaderOffset;
+
+  m_pSyntax->RestorePos(dwStartPos);
+  m_SortedOffset.insert(pos);
+
+  uint32_t start_objnum = 0;
+  uint32_t count = dwObjCount;
+  FX_FILESIZE SavedPos = m_pSyntax->SavePos();
+
+  const int32_t recordsize = 20;
+  std::vector<char> buf(1024 * recordsize + 1);
+  buf[1024 * recordsize] = '\0';
+
+  int32_t nBlocks = count / 1024 + 1;
+  for (int32_t block = 0; block < nBlocks; block++) {
+    int32_t block_size = block == nBlocks - 1 ? count % 1024 : 1024;
+    uint32_t dwReadSize = block_size * recordsize;
+    if ((FX_FILESIZE)(dwStartPos + dwReadSize) > m_pSyntax->m_FileLen)
+      return FALSE;
+
+    if (!m_pSyntax->ReadBlock(reinterpret_cast<uint8_t*>(buf.data()),
+                              dwReadSize)) {
+      return FALSE;
+    }
+
+    for (int32_t i = 0; i < block_size; i++) {
+      uint32_t objnum = start_objnum + block * 1024 + i;
+      char* pEntry = &buf[i * recordsize];
+      if (pEntry[17] == 'f') {
+        m_ObjectInfo[objnum].pos = 0;
+        m_ObjectInfo[objnum].type = 0;
+      } else {
+        int32_t offset = FXSYS_atoi(pEntry);
+        if (offset == 0) {
+          for (int32_t c = 0; c < 10; c++) {
+            if (!std::isdigit(pEntry[c]))
+              return FALSE;
+          }
+        }
+
+        m_ObjectInfo[objnum].pos = offset;
+        int32_t version = FXSYS_atoi(pEntry + 11);
+        if (version >= 1)
+          m_bVersionUpdated = true;
+
+        m_ObjectInfo[objnum].gennum = version;
+        if (m_ObjectInfo[objnum].pos < m_pSyntax->m_FileLen)
+          m_SortedOffset.insert(m_ObjectInfo[objnum].pos);
+
+        m_ObjectInfo[objnum].type = 1;
+      }
+    }
+  }
+  m_pSyntax->RestorePos(SavedPos + count * recordsize);
+  return TRUE;
+}
+
+bool CPDF_Parser::LoadCrossRefV4(FX_FILESIZE pos,
+                                 FX_FILESIZE streampos,
+                                 FX_BOOL bSkip) {
+  m_pSyntax->RestorePos(pos);
+  if (m_pSyntax->GetKeyword() != "xref")
+    return false;
+
+  m_SortedOffset.insert(pos);
+  if (streampos)
+    m_SortedOffset.insert(streampos);
+
+  while (1) {
+    FX_FILESIZE SavedPos = m_pSyntax->SavePos();
+    bool bIsNumber;
+    CFX_ByteString word = m_pSyntax->GetNextWord(&bIsNumber);
+    if (word.IsEmpty())
+      return false;
+
+    if (!bIsNumber) {
+      m_pSyntax->RestorePos(SavedPos);
+      break;
+    }
+
+    uint32_t start_objnum = FXSYS_atoui(word.c_str());
+    if (start_objnum >= kMaxObjectNumber)
+      return false;
+
+    uint32_t count = m_pSyntax->GetDirectNum();
+    m_pSyntax->ToNextWord();
+    SavedPos = m_pSyntax->SavePos();
+    const int32_t recordsize = 20;
+
+    m_dwXrefStartObjNum = start_objnum;
+    if (!bSkip) {
+      std::vector<char> buf(1024 * recordsize + 1);
+      buf[1024 * recordsize] = '\0';
+
+      int32_t nBlocks = count / 1024 + 1;
+      for (int32_t block = 0; block < nBlocks; block++) {
+        int32_t block_size = block == nBlocks - 1 ? count % 1024 : 1024;
+        m_pSyntax->ReadBlock(reinterpret_cast<uint8_t*>(buf.data()),
+                             block_size * recordsize);
+
+        for (int32_t i = 0; i < block_size; i++) {
+          uint32_t objnum = start_objnum + block * 1024 + i;
+          char* pEntry = &buf[i * recordsize];
+          if (pEntry[17] == 'f') {
+            m_ObjectInfo[objnum].pos = 0;
+            m_ObjectInfo[objnum].type = 0;
+          } else {
+            FX_FILESIZE offset = (FX_FILESIZE)FXSYS_atoi64(pEntry);
+            if (offset == 0) {
+              for (int32_t c = 0; c < 10; c++) {
+                if (!std::isdigit(pEntry[c]))
+                  return false;
+              }
+            }
+
+            m_ObjectInfo[objnum].pos = offset;
+            int32_t version = FXSYS_atoi(pEntry + 11);
+            if (version >= 1)
+              m_bVersionUpdated = true;
+
+            m_ObjectInfo[objnum].gennum = version;
+            if (m_ObjectInfo[objnum].pos < m_pSyntax->m_FileLen)
+              m_SortedOffset.insert(m_ObjectInfo[objnum].pos);
+
+            m_ObjectInfo[objnum].type = 1;
+          }
+        }
+      }
+    }
+    m_pSyntax->RestorePos(SavedPos + count * recordsize);
+  }
+  return !streampos || LoadCrossRefV5(&streampos, FALSE);
+}
+
+FX_BOOL CPDF_Parser::LoadAllCrossRefV5(FX_FILESIZE xrefpos) {
+  if (!LoadCrossRefV5(&xrefpos, TRUE))
+    return FALSE;
+
+  std::set<FX_FILESIZE> seen_xrefpos;
+  while (xrefpos) {
+    seen_xrefpos.insert(xrefpos);
+    if (!LoadCrossRefV5(&xrefpos, FALSE))
+      return FALSE;
+
+    // Check for circular references.
+    if (pdfium::ContainsKey(seen_xrefpos, xrefpos))
+      return FALSE;
+  }
+  m_ObjectStreamMap.clear();
+  m_bXRefStream = TRUE;
+  return TRUE;
+}
+
+FX_BOOL CPDF_Parser::RebuildCrossRef() {
+  m_ObjectInfo.clear();
+  m_SortedOffset.clear();
+  if (m_pTrailer) {
+    m_pTrailer->Release();
+    m_pTrailer = nullptr;
+  }
+
+  ParserState state = ParserState::kDefault;
+
+  int32_t inside_index = 0;
+  uint32_t objnum = 0;
+  uint32_t gennum = 0;
+  int32_t depth = 0;
+
+  const uint32_t kBufferSize = 4096;
+  std::vector<uint8_t> buffer(kBufferSize);
+
+  FX_FILESIZE pos = m_pSyntax->m_HeaderOffset;
+  FX_FILESIZE start_pos = 0;
+  FX_FILESIZE start_pos1 = 0;
+  FX_FILESIZE last_obj = -1;
+  FX_FILESIZE last_xref = -1;
+  FX_FILESIZE last_trailer = -1;
+
+  while (pos < m_pSyntax->m_FileLen) {
+    const FX_FILESIZE saved_pos = pos;
+    bool bOverFlow = false;
+    uint32_t size =
+        std::min((uint32_t)(m_pSyntax->m_FileLen - pos), kBufferSize);
+    if (!m_pSyntax->m_pFileAccess->ReadBlock(buffer.data(), pos, size))
+      break;
+
+    for (uint32_t i = 0; i < size; i++) {
+      uint8_t byte = buffer[i];
+      switch (state) {
+        case ParserState::kDefault:
+          if (PDFCharIsWhitespace(byte)) {
+            state = ParserState::kWhitespace;
+          } else if (std::isdigit(byte)) {
+            --i;
+            state = ParserState::kWhitespace;
+          } else if (byte == '%') {
+            inside_index = 0;
+            state = ParserState::kComment;
+          } else if (byte == '(') {
+            state = ParserState::kString;
+            depth = 1;
+          } else if (byte == '<') {
+            inside_index = 1;
+            state = ParserState::kHexString;
+          } else if (byte == '\\') {
+            state = ParserState::kEscapedString;
+          } else if (byte == 't') {
+            state = ParserState::kTrailer;
+            inside_index = 1;
+          }
+          break;
+
+        case ParserState::kWhitespace:
+          if (std::isdigit(byte)) {
+            start_pos = pos + i;
+            state = ParserState::kObjNum;
+            objnum = FXSYS_toDecimalDigit(static_cast<FX_WCHAR>(byte));
+          } else if (byte == 't') {
+            state = ParserState::kTrailer;
+            inside_index = 1;
+          } else if (byte == 'x') {
+            state = ParserState::kXref;
+            inside_index = 1;
+          } else if (!PDFCharIsWhitespace(byte)) {
+            --i;
+            state = ParserState::kDefault;
+          }
+          break;
+
+        case ParserState::kObjNum:
+          if (std::isdigit(byte)) {
+            objnum =
+                objnum * 10 + FXSYS_toDecimalDigit(static_cast<FX_WCHAR>(byte));
+          } else if (PDFCharIsWhitespace(byte)) {
+            state = ParserState::kPostObjNum;
+          } else {
+            --i;
+            state = ParserState::kEndObj;
+            inside_index = 0;
+          }
+          break;
+
+        case ParserState::kPostObjNum:
+          if (std::isdigit(byte)) {
+            start_pos1 = pos + i;
+            state = ParserState::kGenNum;
+            gennum = FXSYS_toDecimalDigit(static_cast<FX_WCHAR>(byte));
+          } else if (byte == 't') {
+            state = ParserState::kTrailer;
+            inside_index = 1;
+          } else if (!PDFCharIsWhitespace(byte)) {
+            --i;
+            state = ParserState::kDefault;
+          }
+          break;
+
+        case ParserState::kGenNum:
+          if (std::isdigit(byte)) {
+            gennum =
+                gennum * 10 + FXSYS_toDecimalDigit(static_cast<FX_WCHAR>(byte));
+          } else if (PDFCharIsWhitespace(byte)) {
+            state = ParserState::kPostGenNum;
+          } else {
+            --i;
+            state = ParserState::kDefault;
+          }
+          break;
+
+        case ParserState::kPostGenNum:
+          if (byte == 'o') {
+            state = ParserState::kBeginObj;
+            inside_index = 1;
+          } else if (std::isdigit(byte)) {
+            objnum = gennum;
+            gennum = FXSYS_toDecimalDigit(static_cast<FX_WCHAR>(byte));
+            start_pos = start_pos1;
+            start_pos1 = pos + i;
+            state = ParserState::kGenNum;
+          } else if (byte == 't') {
+            state = ParserState::kTrailer;
+            inside_index = 1;
+          } else if (!PDFCharIsWhitespace(byte)) {
+            --i;
+            state = ParserState::kDefault;
+          }
+          break;
+
+        case ParserState::kBeginObj:
+          switch (inside_index) {
+            case 1:
+              if (byte != 'b') {
+                --i;
+                state = ParserState::kDefault;
+              } else {
+                inside_index++;
+              }
+              break;
+            case 2:
+              if (byte != 'j') {
+                --i;
+                state = ParserState::kDefault;
+              } else {
+                inside_index++;
+              }
+              break;
+            case 3:
+              if (PDFCharIsWhitespace(byte) || PDFCharIsDelimiter(byte)) {
+                FX_FILESIZE obj_pos = start_pos - m_pSyntax->m_HeaderOffset;
+                m_SortedOffset.insert(obj_pos);
+                last_obj = start_pos;
+                FX_FILESIZE obj_end = 0;
+                CPDF_Object* pObject = ParseIndirectObjectAtByStrict(
+                    m_pDocument, obj_pos, objnum, &obj_end);
+                if (CPDF_Stream* pStream = ToStream(pObject)) {
+                  if (CPDF_Dictionary* pDict = pStream->GetDict()) {
+                    if ((pDict->KeyExist("Type")) &&
+                        (pDict->GetStringFor("Type") == "XRef" &&
+                         pDict->KeyExist("Size"))) {
+                      CPDF_Object* pRoot = pDict->GetObjectFor("Root");
+                      if (pRoot && pRoot->GetDict() &&
+                          pRoot->GetDict()->GetObjectFor("Pages")) {
+                        if (m_pTrailer)
+                          m_pTrailer->Release();
+                        m_pTrailer = ToDictionary(pDict->Clone());
+                      }
+                    }
+                  }
+                }
+
+                FX_FILESIZE offset = 0;
+                m_pSyntax->RestorePos(obj_pos);
+                offset = m_pSyntax->FindTag("obj", 0);
+                if (offset == -1)
+                  offset = 0;
+                else
+                  offset += 3;
+
+                FX_FILESIZE nLen = obj_end - obj_pos - offset;
+                if ((uint32_t)nLen > size - i) {
+                  pos = obj_end + m_pSyntax->m_HeaderOffset;
+                  bOverFlow = true;
+                } else {
+                  i += (uint32_t)nLen;
+                }
+
+                if (!m_ObjectInfo.empty() && IsValidObjectNumber(objnum) &&
+                    m_ObjectInfo[objnum].pos) {
+                  if (pObject) {
+                    uint32_t oldgen = GetObjectGenNum(objnum);
+                    m_ObjectInfo[objnum].pos = obj_pos;
+                    m_ObjectInfo[objnum].gennum = gennum;
+                    if (oldgen != gennum)
+                      m_bVersionUpdated = true;
+                  }
+                } else {
+                  m_ObjectInfo[objnum].pos = obj_pos;
+                  m_ObjectInfo[objnum].type = 1;
+                  m_ObjectInfo[objnum].gennum = gennum;
+                }
+
+                if (pObject)
+                  pObject->Release();
+              }
+              --i;
+              state = ParserState::kDefault;
+              break;
+          }
+          break;
+
+        case ParserState::kTrailer:
+          if (inside_index == 7) {
+            if (PDFCharIsWhitespace(byte) || PDFCharIsDelimiter(byte)) {
+              last_trailer = pos + i - 7;
+              m_pSyntax->RestorePos(pos + i - m_pSyntax->m_HeaderOffset);
+
+              CPDF_Object* pObj = m_pSyntax->GetObject(m_pDocument, 0, 0, true);
+              if (pObj) {
+                if (!pObj->IsDictionary() && !pObj->AsStream()) {
+                  pObj->Release();
+                } else {
+                  CPDF_Stream* pStream = pObj->AsStream();
+                  if (CPDF_Dictionary* pTrailer =
+                          pStream ? pStream->GetDict() : pObj->AsDictionary()) {
+                    if (m_pTrailer) {
+                      CPDF_Object* pRoot = pTrailer->GetObjectFor("Root");
+                      CPDF_Reference* pRef = ToReference(pRoot);
+                      if (!pRoot ||
+                          (pRef && IsValidObjectNumber(pRef->GetRefObjNum()) &&
+                           m_ObjectInfo[pRef->GetRefObjNum()].pos != 0)) {
+                        auto it = pTrailer->begin();
+                        while (it != pTrailer->end()) {
+                          const CFX_ByteString& key = it->first;
+                          CPDF_Object* pElement = it->second;
+                          ++it;
+                          uint32_t dwObjNum =
+                              pElement ? pElement->GetObjNum() : 0;
+                          if (dwObjNum) {
+                            m_pTrailer->SetReferenceFor(key, m_pDocument,
+                                                        dwObjNum);
+                          } else {
+                            m_pTrailer->SetFor(key, pElement->Clone());
+                          }
+                        }
+                      }
+                      pObj->Release();
+                    } else {
+                      if (pObj->IsStream()) {
+                        m_pTrailer = ToDictionary(pTrailer->Clone());
+                        pObj->Release();
+                      } else {
+                        m_pTrailer = pTrailer;
+                      }
+
+                      FX_FILESIZE dwSavePos = m_pSyntax->SavePos();
+                      CFX_ByteString strWord = m_pSyntax->GetKeyword();
+                      if (!strWord.Compare("startxref")) {
+                        bool bNumber;
+                        CFX_ByteString bsOffset =
+                            m_pSyntax->GetNextWord(&bNumber);
+                        if (bNumber)
+                          m_LastXRefOffset = FXSYS_atoi(bsOffset.c_str());
+                      }
+                      m_pSyntax->RestorePos(dwSavePos);
+                    }
+                  } else {
+                    pObj->Release();
+                  }
+                }
+              }
+            }
+            --i;
+            state = ParserState::kDefault;
+          } else if (byte == "trailer"[inside_index]) {
+            inside_index++;
+          } else {
+            --i;
+            state = ParserState::kDefault;
+          }
+          break;
+
+        case ParserState::kXref:
+          if (inside_index == 4) {
+            last_xref = pos + i - 4;
+            state = ParserState::kWhitespace;
+          } else if (byte == "xref"[inside_index]) {
+            inside_index++;
+          } else {
+            --i;
+            state = ParserState::kDefault;
+          }
+          break;
+
+        case ParserState::kComment:
+          if (PDFCharIsLineEnding(byte))
+            state = ParserState::kDefault;
+          break;
+
+        case ParserState::kString:
+          if (byte == ')') {
+            if (depth > 0)
+              depth--;
+          } else if (byte == '(') {
+            depth++;
+          }
+
+          if (!depth)
+            state = ParserState::kDefault;
+          break;
+
+        case ParserState::kHexString:
+          if (byte == '>' || (byte == '<' && inside_index == 1))
+            state = ParserState::kDefault;
+          inside_index = 0;
+          break;
+
+        case ParserState::kEscapedString:
+          if (PDFCharIsDelimiter(byte) || PDFCharIsWhitespace(byte)) {
+            --i;
+            state = ParserState::kDefault;
+          }
+          break;
+
+        case ParserState::kEndObj:
+          if (PDFCharIsWhitespace(byte)) {
+            state = ParserState::kDefault;
+          } else if (byte == '%' || byte == '(' || byte == '<' ||
+                     byte == '\\') {
+            state = ParserState::kDefault;
+            --i;
+          } else if (inside_index == 6) {
+            state = ParserState::kDefault;
+            --i;
+          } else if (byte == "endobj"[inside_index]) {
+            inside_index++;
+          }
+          break;
+      }
+
+      if (bOverFlow) {
+        size = 0;
+        break;
+      }
+    }
+    pos += size;
+
+    // If the position has not changed at all or went backwards in a loop
+    // iteration, then break out to prevent infinite looping.
+    if (pos <= saved_pos)
+      break;
+  }
+
+  if (last_xref != -1 && last_xref > last_obj)
+    last_trailer = last_xref;
+  else if (last_trailer == -1 || last_xref < last_obj)
+    last_trailer = m_pSyntax->m_FileLen;
+
+  m_SortedOffset.insert(last_trailer - m_pSyntax->m_HeaderOffset);
+  return m_pTrailer && !m_ObjectInfo.empty();
+}
+
+FX_BOOL CPDF_Parser::LoadCrossRefV5(FX_FILESIZE* pos, FX_BOOL bMainXRef) {
+  CPDF_Object* pObject = ParseIndirectObjectAt(m_pDocument, *pos, 0);
+  if (!pObject)
+    return FALSE;
+
+  if (m_pDocument) {
+    CPDF_Dictionary* pRootDict = m_pDocument->GetRoot();
+    if (pRootDict && pRootDict->GetObjNum() == pObject->m_ObjNum) {
+      // If |pObject| has an objnum assigned then this will leak as Release()
+      // will early exit.
+      if (pObject->IsStream())
+        pObject->Release();
+      return FALSE;
+    }
+    if (!m_pDocument->ReplaceIndirectObjectIfHigherGeneration(pObject->m_ObjNum,
+                                                              pObject)) {
+      return FALSE;
+    }
+  }
+
+  CPDF_Stream* pStream = pObject->AsStream();
+  if (!pStream)
+    return FALSE;
+
+  CPDF_Dictionary* pDict = pStream->GetDict();
+  *pos = pDict->GetIntegerFor("Prev");
+  int32_t size = pDict->GetIntegerFor("Size");
+  if (size < 0) {
+    pStream->Release();
+    return FALSE;
+  }
+
+  CPDF_Dictionary* pNewTrailer = ToDictionary(pDict->Clone());
+  if (bMainXRef) {
+    m_pTrailer = pNewTrailer;
+    ShrinkObjectMap(size);
+    for (auto& it : m_ObjectInfo)
+      it.second.type = 0;
+  } else {
+    m_Trailers.Add(pNewTrailer);
+  }
+
+  std::vector<std::pair<int32_t, int32_t>> arrIndex;
+  CPDF_Array* pArray = pDict->GetArrayFor("Index");
+  if (pArray) {
+    for (size_t i = 0; i < pArray->GetCount() / 2; i++) {
+      CPDF_Object* pStartNumObj = pArray->GetObjectAt(i * 2);
+      CPDF_Object* pCountObj = pArray->GetObjectAt(i * 2 + 1);
+
+      if (ToNumber(pStartNumObj) && ToNumber(pCountObj)) {
+        int nStartNum = pStartNumObj->GetInteger();
+        int nCount = pCountObj->GetInteger();
+        if (nStartNum >= 0 && nCount > 0)
+          arrIndex.push_back(std::make_pair(nStartNum, nCount));
+      }
+    }
+  }
+
+  if (arrIndex.size() == 0)
+    arrIndex.push_back(std::make_pair(0, size));
+
+  pArray = pDict->GetArrayFor("W");
+  if (!pArray) {
+    pStream->Release();
+    return FALSE;
+  }
+
+  CFX_ArrayTemplate<uint32_t> WidthArray;
+  FX_SAFE_UINT32 dwAccWidth = 0;
+  for (size_t i = 0; i < pArray->GetCount(); ++i) {
+    WidthArray.Add(pArray->GetIntegerAt(i));
+    dwAccWidth += WidthArray[i];
+  }
+
+  if (!dwAccWidth.IsValid() || WidthArray.GetSize() < 3) {
+    pStream->Release();
+    return FALSE;
+  }
+
+  uint32_t totalWidth = dwAccWidth.ValueOrDie();
+  CPDF_StreamAcc acc;
+  acc.LoadAllData(pStream);
+
+  const uint8_t* pData = acc.GetData();
+  uint32_t dwTotalSize = acc.GetSize();
+  uint32_t segindex = 0;
+  for (uint32_t i = 0; i < arrIndex.size(); i++) {
+    int32_t startnum = arrIndex[i].first;
+    if (startnum < 0)
+      continue;
+
+    m_dwXrefStartObjNum =
+        pdfium::base::checked_cast<uint32_t, int32_t>(startnum);
+    uint32_t count =
+        pdfium::base::checked_cast<uint32_t, int32_t>(arrIndex[i].second);
+    FX_SAFE_UINT32 dwCaculatedSize = segindex;
+    dwCaculatedSize += count;
+    dwCaculatedSize *= totalWidth;
+    if (!dwCaculatedSize.IsValid() ||
+        dwCaculatedSize.ValueOrDie() > dwTotalSize) {
+      continue;
+    }
+
+    const uint8_t* segstart = pData + segindex * totalWidth;
+    FX_SAFE_UINT32 dwMaxObjNum = startnum;
+    dwMaxObjNum += count;
+    uint32_t dwV5Size = m_ObjectInfo.empty() ? 0 : GetLastObjNum() + 1;
+    if (!dwMaxObjNum.IsValid() || dwMaxObjNum.ValueOrDie() > dwV5Size)
+      continue;
+
+    for (uint32_t j = 0; j < count; j++) {
+      int32_t type = 1;
+      const uint8_t* entrystart = segstart + j * totalWidth;
+      if (WidthArray[0])
+        type = GetVarInt(entrystart, WidthArray[0]);
+
+      if (GetObjectType(startnum + j) == 255) {
+        FX_FILESIZE offset =
+            GetVarInt(entrystart + WidthArray[0], WidthArray[1]);
+        m_ObjectInfo[startnum + j].pos = offset;
+        m_SortedOffset.insert(offset);
+        continue;
+      }
+
+      if (GetObjectType(startnum + j))
+        continue;
+
+      m_ObjectInfo[startnum + j].type = type;
+      if (type == 0) {
+        m_ObjectInfo[startnum + j].pos = 0;
+      } else {
+        FX_FILESIZE offset =
+            GetVarInt(entrystart + WidthArray[0], WidthArray[1]);
+        m_ObjectInfo[startnum + j].pos = offset;
+        if (type == 1) {
+          m_SortedOffset.insert(offset);
+        } else {
+          if (offset < 0 || !IsValidObjectNumber(offset)) {
+            pStream->Release();
+            return FALSE;
+          }
+          m_ObjectInfo[offset].type = 255;
+        }
+      }
+    }
+    segindex += count;
+  }
+  pStream->Release();
+  return TRUE;
+}
+
+CPDF_Array* CPDF_Parser::GetIDArray() {
+  CPDF_Object* pID = m_pTrailer ? m_pTrailer->GetObjectFor("ID") : nullptr;
+  if (!pID)
+    return nullptr;
+
+  if (CPDF_Reference* pRef = pID->AsReference()) {
+    pID = ParseIndirectObject(nullptr, pRef->GetRefObjNum());
+    m_pTrailer->SetFor("ID", pID);
+  }
+  return ToArray(pID);
+}
+
+uint32_t CPDF_Parser::GetRootObjNum() {
+  CPDF_Reference* pRef =
+      ToReference(m_pTrailer ? m_pTrailer->GetObjectFor("Root") : nullptr);
+  return pRef ? pRef->GetRefObjNum() : 0;
+}
+
+uint32_t CPDF_Parser::GetInfoObjNum() {
+  CPDF_Reference* pRef =
+      ToReference(m_pTrailer ? m_pTrailer->GetObjectFor("Info") : nullptr);
+  return pRef ? pRef->GetRefObjNum() : 0;
+}
+
+CPDF_Object* CPDF_Parser::ParseIndirectObject(
+    CPDF_IndirectObjectHolder* pObjList,
+    uint32_t objnum) {
+  if (!IsValidObjectNumber(objnum))
+    return nullptr;
+
+  // Prevent circular parsing the same object.
+  if (pdfium::ContainsKey(m_ParsingObjNums, objnum))
+    return nullptr;
+
+  pdfium::ScopedSetInsertion<uint32_t> local_insert(&m_ParsingObjNums, objnum);
+  if (GetObjectType(objnum) == 1 || GetObjectType(objnum) == 255) {
+    FX_FILESIZE pos = m_ObjectInfo[objnum].pos;
+    if (pos <= 0)
+      return nullptr;
+    return ParseIndirectObjectAt(pObjList, pos, objnum);
+  }
+  if (GetObjectType(objnum) != 2)
+    return nullptr;
+
+  CPDF_StreamAcc* pObjStream = GetObjectStream(m_ObjectInfo[objnum].pos);
+  if (!pObjStream)
+    return nullptr;
+
+  ScopedFileStream file(FX_CreateMemoryStream(
+      (uint8_t*)pObjStream->GetData(), (size_t)pObjStream->GetSize(), FALSE));
+  CPDF_SyntaxParser syntax;
+  syntax.InitParser(file.get(), 0);
+  const int32_t offset = GetStreamFirst(pObjStream);
+
+  // Read object numbers from |pObjStream| into a cache.
+  if (!pdfium::ContainsKey(m_ObjCache, pObjStream)) {
+    for (int32_t i = GetStreamNCount(pObjStream); i > 0; --i) {
+      uint32_t thisnum = syntax.GetDirectNum();
+      uint32_t thisoff = syntax.GetDirectNum();
+      m_ObjCache[pObjStream][thisnum] = thisoff;
+    }
+  }
+
+  const auto it = m_ObjCache[pObjStream].find(objnum);
+  if (it == m_ObjCache[pObjStream].end())
+    return nullptr;
+
+  syntax.RestorePos(offset + it->second);
+  return syntax.GetObject(pObjList, 0, 0, true);
+}
+
+CPDF_StreamAcc* CPDF_Parser::GetObjectStream(uint32_t objnum) {
+  auto it = m_ObjectStreamMap.find(objnum);
+  if (it != m_ObjectStreamMap.end())
+    return it->second.get();
+
+  if (!m_pDocument)
+    return nullptr;
+
+  const CPDF_Stream* pStream =
+      ToStream(m_pDocument->GetOrParseIndirectObject(objnum));
+  if (!pStream)
+    return nullptr;
+
+  CPDF_StreamAcc* pStreamAcc = new CPDF_StreamAcc;
+  pStreamAcc->LoadAllData(pStream);
+  m_ObjectStreamMap[objnum].reset(pStreamAcc);
+  return pStreamAcc;
+}
+
+FX_FILESIZE CPDF_Parser::GetObjectSize(uint32_t objnum) const {
+  if (!IsValidObjectNumber(objnum))
+    return 0;
+
+  if (GetObjectType(objnum) == 2)
+    objnum = GetObjectPositionOrZero(objnum);
+
+  if (GetObjectType(objnum) != 1 && GetObjectType(objnum) != 255)
+    return 0;
+
+  FX_FILESIZE offset = GetObjectPositionOrZero(objnum);
+  if (offset == 0)
+    return 0;
+
+  auto it = m_SortedOffset.find(offset);
+  if (it == m_SortedOffset.end() || ++it == m_SortedOffset.end())
+    return 0;
+
+  return *it - offset;
+}
+
+void CPDF_Parser::GetIndirectBinary(uint32_t objnum,
+                                    uint8_t*& pBuffer,
+                                    uint32_t& size) {
+  pBuffer = nullptr;
+  size = 0;
+  if (!IsValidObjectNumber(objnum))
+    return;
+
+  if (GetObjectType(objnum) == 2) {
+    CPDF_StreamAcc* pObjStream = GetObjectStream(m_ObjectInfo[objnum].pos);
+    if (!pObjStream)
+      return;
+
+    int32_t offset = GetStreamFirst(pObjStream);
+    const uint8_t* pData = pObjStream->GetData();
+    uint32_t totalsize = pObjStream->GetSize();
+    ScopedFileStream file(
+        FX_CreateMemoryStream((uint8_t*)pData, (size_t)totalsize, FALSE));
+
+    CPDF_SyntaxParser syntax;
+    syntax.InitParser(file.get(), 0);
+    for (int i = GetStreamNCount(pObjStream); i > 0; --i) {
+      uint32_t thisnum = syntax.GetDirectNum();
+      uint32_t thisoff = syntax.GetDirectNum();
+      if (thisnum != objnum)
+        continue;
+
+      if (i == 1) {
+        size = totalsize - (thisoff + offset);
+      } else {
+        syntax.GetDirectNum();  // Skip nextnum.
+        uint32_t nextoff = syntax.GetDirectNum();
+        size = nextoff - thisoff;
+      }
+
+      pBuffer = FX_Alloc(uint8_t, size);
+      FXSYS_memcpy(pBuffer, pData + thisoff + offset, size);
+      return;
+    }
+    return;
+  }
+
+  if (GetObjectType(objnum) != 1)
+    return;
+
+  FX_FILESIZE pos = m_ObjectInfo[objnum].pos;
+  if (pos == 0)
+    return;
+
+  FX_FILESIZE SavedPos = m_pSyntax->SavePos();
+  m_pSyntax->RestorePos(pos);
+
+  bool bIsNumber;
+  CFX_ByteString word = m_pSyntax->GetNextWord(&bIsNumber);
+  if (!bIsNumber) {
+    m_pSyntax->RestorePos(SavedPos);
+    return;
+  }
+
+  uint32_t parser_objnum = FXSYS_atoui(word.c_str());
+  if (parser_objnum && parser_objnum != objnum) {
+    m_pSyntax->RestorePos(SavedPos);
+    return;
+  }
+
+  word = m_pSyntax->GetNextWord(&bIsNumber);
+  if (!bIsNumber) {
+    m_pSyntax->RestorePos(SavedPos);
+    return;
+  }
+
+  if (m_pSyntax->GetKeyword() != "obj") {
+    m_pSyntax->RestorePos(SavedPos);
+    return;
+  }
+
+  auto it = m_SortedOffset.find(pos);
+  if (it == m_SortedOffset.end() || ++it == m_SortedOffset.end()) {
+    m_pSyntax->RestorePos(SavedPos);
+    return;
+  }
+
+  FX_FILESIZE nextoff = *it;
+  FX_BOOL bNextOffValid = FALSE;
+  if (nextoff != pos) {
+    m_pSyntax->RestorePos(nextoff);
+    word = m_pSyntax->GetNextWord(&bIsNumber);
+    if (word == "xref") {
+      bNextOffValid = TRUE;
+    } else if (bIsNumber) {
+      word = m_pSyntax->GetNextWord(&bIsNumber);
+      if (bIsNumber && m_pSyntax->GetKeyword() == "obj") {
+        bNextOffValid = TRUE;
+      }
+    }
+  }
+
+  if (!bNextOffValid) {
+    m_pSyntax->RestorePos(pos);
+    while (1) {
+      if (m_pSyntax->GetKeyword() == "endobj")
+        break;
+
+      if (m_pSyntax->SavePos() == m_pSyntax->m_FileLen)
+        break;
+    }
+    nextoff = m_pSyntax->SavePos();
+  }
+
+  size = (uint32_t)(nextoff - pos);
+  pBuffer = FX_Alloc(uint8_t, size);
+  m_pSyntax->RestorePos(pos);
+  m_pSyntax->ReadBlock(pBuffer, size);
+  m_pSyntax->RestorePos(SavedPos);
+}
+
+CPDF_Object* CPDF_Parser::ParseIndirectObjectAt(
+    CPDF_IndirectObjectHolder* pObjList,
+    FX_FILESIZE pos,
+    uint32_t objnum) {
+  FX_FILESIZE SavedPos = m_pSyntax->SavePos();
+  m_pSyntax->RestorePos(pos);
+  bool bIsNumber;
+  CFX_ByteString word = m_pSyntax->GetNextWord(&bIsNumber);
+  if (!bIsNumber) {
+    m_pSyntax->RestorePos(SavedPos);
+    return nullptr;
+  }
+
+  FX_FILESIZE objOffset = m_pSyntax->SavePos();
+  objOffset -= word.GetLength();
+  uint32_t parser_objnum = FXSYS_atoui(word.c_str());
+  if (objnum && parser_objnum != objnum) {
+    m_pSyntax->RestorePos(SavedPos);
+    return nullptr;
+  }
+
+  word = m_pSyntax->GetNextWord(&bIsNumber);
+  if (!bIsNumber) {
+    m_pSyntax->RestorePos(SavedPos);
+    return nullptr;
+  }
+
+  uint32_t parser_gennum = FXSYS_atoui(word.c_str());
+  if (m_pSyntax->GetKeyword() != "obj") {
+    m_pSyntax->RestorePos(SavedPos);
+    return nullptr;
+  }
+
+  CPDF_Object* pObj =
+      m_pSyntax->GetObject(pObjList, objnum, parser_gennum, true);
+  m_pSyntax->SavePos();
+
+  CFX_ByteString bsWord = m_pSyntax->GetKeyword();
+  if (bsWord == "endobj")
+    m_pSyntax->SavePos();
+
+  m_pSyntax->RestorePos(SavedPos);
+  if (pObj) {
+    if (!objnum)
+      pObj->m_ObjNum = parser_objnum;
+    pObj->m_GenNum = parser_gennum;
+  }
+  return pObj;
+}
+
+CPDF_Object* CPDF_Parser::ParseIndirectObjectAtByStrict(
+    CPDF_IndirectObjectHolder* pObjList,
+    FX_FILESIZE pos,
+    uint32_t objnum,
+    FX_FILESIZE* pResultPos) {
+  FX_FILESIZE SavedPos = m_pSyntax->SavePos();
+  m_pSyntax->RestorePos(pos);
+
+  bool bIsNumber;
+  CFX_ByteString word = m_pSyntax->GetNextWord(&bIsNumber);
+  if (!bIsNumber) {
+    m_pSyntax->RestorePos(SavedPos);
+    return nullptr;
+  }
+
+  uint32_t parser_objnum = FXSYS_atoui(word.c_str());
+  if (objnum && parser_objnum != objnum) {
+    m_pSyntax->RestorePos(SavedPos);
+    return nullptr;
+  }
+
+  word = m_pSyntax->GetNextWord(&bIsNumber);
+  if (!bIsNumber) {
+    m_pSyntax->RestorePos(SavedPos);
+    return nullptr;
+  }
+
+  uint32_t gennum = FXSYS_atoui(word.c_str());
+  if (m_pSyntax->GetKeyword() != "obj") {
+    m_pSyntax->RestorePos(SavedPos);
+    return nullptr;
+  }
+
+  CPDF_Object* pObj = m_pSyntax->GetObjectForStrict(pObjList, objnum, gennum);
+  if (pResultPos)
+    *pResultPos = m_pSyntax->m_Pos;
+
+  m_pSyntax->RestorePos(SavedPos);
+  return pObj;
+}
+
+CPDF_Dictionary* CPDF_Parser::LoadTrailerV4() {
+  if (m_pSyntax->GetKeyword() != "trailer")
+    return nullptr;
+
+  std::unique_ptr<CPDF_Object, ReleaseDeleter<CPDF_Object>> pObj(
+      m_pSyntax->GetObject(m_pDocument, 0, 0, true));
+  if (!ToDictionary(pObj.get()))
+    return nullptr;
+  return pObj.release()->AsDictionary();
+}
+
+uint32_t CPDF_Parser::GetPermissions() const {
+  if (!m_pSecurityHandler)
+    return 0xFFFFFFFF;
+
+  uint32_t dwPermission = m_pSecurityHandler->GetPermissions();
+  if (m_pEncryptDict && m_pEncryptDict->GetStringFor("Filter") == "Standard") {
+    // See PDF Reference 1.7, page 123, table 3.20.
+    dwPermission &= 0xFFFFFFFC;
+    dwPermission |= 0xFFFFF0C0;
+  }
+  return dwPermission;
+}
+
+FX_BOOL CPDF_Parser::IsLinearizedFile(IFX_FileRead* pFileAccess,
+                                      uint32_t offset) {
+  m_pSyntax->InitParser(pFileAccess, offset);
+  m_pSyntax->RestorePos(m_pSyntax->m_HeaderOffset + 9);
+
+  FX_FILESIZE SavedPos = m_pSyntax->SavePos();
+  bool bIsNumber;
+  CFX_ByteString word = m_pSyntax->GetNextWord(&bIsNumber);
+  if (!bIsNumber)
+    return FALSE;
+
+  uint32_t objnum = FXSYS_atoui(word.c_str());
+  word = m_pSyntax->GetNextWord(&bIsNumber);
+  if (!bIsNumber)
+    return FALSE;
+
+  uint32_t gennum = FXSYS_atoui(word.c_str());
+  if (m_pSyntax->GetKeyword() != "obj") {
+    m_pSyntax->RestorePos(SavedPos);
+    return FALSE;
+  }
+
+  m_pLinearized = m_pSyntax->GetObject(nullptr, objnum, gennum, true);
+  if (!m_pLinearized)
+    return FALSE;
+
+  CPDF_Dictionary* pDict = m_pLinearized->GetDict();
+  if (pDict && pDict->GetObjectFor("Linearized")) {
+    m_pSyntax->GetNextWord(nullptr);
+
+    CPDF_Object* pLen = pDict->GetObjectFor("L");
+    if (!pLen) {
+      m_pLinearized->Release();
+      m_pLinearized = nullptr;
+      return FALSE;
+    }
+
+    if (pLen->GetInteger() != (int)pFileAccess->GetSize())
+      return FALSE;
+
+    if (CPDF_Number* pNo = ToNumber(pDict->GetObjectFor("P")))
+      m_dwFirstPageNo = pNo->GetInteger();
+
+    if (CPDF_Number* pTable = ToNumber(pDict->GetObjectFor("T")))
+      m_LastXRefOffset = pTable->GetInteger();
+
+    return TRUE;
+  }
+  m_pLinearized->Release();
+  m_pLinearized = nullptr;
+  return FALSE;
+}
+
+CPDF_Parser::Error CPDF_Parser::StartLinearizedParse(IFX_FileRead* pFileAccess,
+                                                     CPDF_Document* pDocument) {
+  ASSERT(!m_bHasParsed);
+
+  m_bXRefStream = FALSE;
+  m_LastXRefOffset = 0;
+  m_bOwnFileRead = true;
+
+  int32_t offset = GetHeaderOffset(pFileAccess);
+  if (offset == -1)
+    return FORMAT_ERROR;
+
+  if (!IsLinearizedFile(pFileAccess, offset)) {
+    m_pSyntax->m_pFileAccess = nullptr;
+    return StartParse(pFileAccess, std::move(pDocument));
+  }
+  m_bHasParsed = true;
+  m_pDocument = pDocument;
+
+  FX_FILESIZE dwFirstXRefOffset = m_pSyntax->SavePos();
+
+  FX_BOOL bXRefRebuilt = FALSE;
+  FX_BOOL bLoadV4 = LoadCrossRefV4(dwFirstXRefOffset, 0, FALSE);
+  if (!bLoadV4 && !LoadCrossRefV5(&dwFirstXRefOffset, TRUE)) {
+    if (!RebuildCrossRef())
+      return FORMAT_ERROR;
+
+    bXRefRebuilt = TRUE;
+    m_LastXRefOffset = 0;
+  }
+
+  if (bLoadV4) {
+    m_pTrailer = LoadTrailerV4();
+    if (!m_pTrailer)
+      return SUCCESS;
+
+    int32_t xrefsize = GetDirectInteger(m_pTrailer, "Size");
+    if (xrefsize > 0)
+      ShrinkObjectMap(xrefsize);
+  }
+
+  Error eRet = SetEncryptHandler();
+  if (eRet != SUCCESS)
+    return eRet;
+
+  m_pDocument->LoadLinearizedDoc(m_pLinearized->GetDict());
+  if (!m_pDocument->GetRoot() || m_pDocument->GetPageCount() == 0) {
+    if (bXRefRebuilt)
+      return FORMAT_ERROR;
+
+    ReleaseEncryptHandler();
+    if (!RebuildCrossRef())
+      return FORMAT_ERROR;
+
+    eRet = SetEncryptHandler();
+    if (eRet != SUCCESS)
+      return eRet;
+
+    m_pDocument->LoadLinearizedDoc(m_pLinearized->GetDict());
+    if (!m_pDocument->GetRoot())
+      return FORMAT_ERROR;
+  }
+
+  if (GetRootObjNum() == 0) {
+    ReleaseEncryptHandler();
+    if (!RebuildCrossRef() || GetRootObjNum() == 0)
+      return FORMAT_ERROR;
+
+    eRet = SetEncryptHandler();
+    if (eRet != SUCCESS)
+      return eRet;
+  }
+
+  if (m_pSecurityHandler && m_pSecurityHandler->IsMetadataEncrypted()) {
+    if (CPDF_Reference* pMetadata =
+            ToReference(m_pDocument->GetRoot()->GetObjectFor("Metadata")))
+      m_pSyntax->m_MetadataObjnum = pMetadata->GetRefObjNum();
+  }
+  return SUCCESS;
+}
+
+FX_BOOL CPDF_Parser::LoadLinearizedAllCrossRefV5(FX_FILESIZE xrefpos) {
+  if (!LoadCrossRefV5(&xrefpos, FALSE))
+    return FALSE;
+
+  std::set<FX_FILESIZE> seen_xrefpos;
+  while (xrefpos) {
+    seen_xrefpos.insert(xrefpos);
+    if (!LoadCrossRefV5(&xrefpos, FALSE))
+      return FALSE;
+
+    // Check for circular references.
+    if (pdfium::ContainsKey(seen_xrefpos, xrefpos))
+      return FALSE;
+  }
+  m_ObjectStreamMap.clear();
+  m_bXRefStream = TRUE;
+  return TRUE;
+}
+
+CPDF_Parser::Error CPDF_Parser::LoadLinearizedMainXRefTable() {
+  uint32_t dwSaveMetadataObjnum = m_pSyntax->m_MetadataObjnum;
+  m_pSyntax->m_MetadataObjnum = 0;
+  if (m_pTrailer) {
+    m_pTrailer->Release();
+    m_pTrailer = nullptr;
+  }
+
+  m_pSyntax->RestorePos(m_LastXRefOffset - m_pSyntax->m_HeaderOffset);
+  uint8_t ch = 0;
+  uint32_t dwCount = 0;
+  m_pSyntax->GetNextChar(ch);
+  while (PDFCharIsWhitespace(ch)) {
+    ++dwCount;
+    if (m_pSyntax->m_FileLen >=
+        (FX_FILESIZE)(m_pSyntax->SavePos() + m_pSyntax->m_HeaderOffset)) {
+      break;
+    }
+    m_pSyntax->GetNextChar(ch);
+  }
+  m_LastXRefOffset += dwCount;
+  m_ObjectStreamMap.clear();
+  m_ObjCache.clear();
+
+  if (!LoadLinearizedAllCrossRefV4(m_LastXRefOffset, m_dwXrefStartObjNum) &&
+      !LoadLinearizedAllCrossRefV5(m_LastXRefOffset)) {
+    m_LastXRefOffset = 0;
+    m_pSyntax->m_MetadataObjnum = dwSaveMetadataObjnum;
+    return FORMAT_ERROR;
+  }
+
+  m_pSyntax->m_MetadataObjnum = dwSaveMetadataObjnum;
+  return SUCCESS;
+}
diff --git a/core/fpdfapi/parser/cpdf_parser.h b/core/fpdfapi/parser/cpdf_parser.h
new file mode 100644
index 0000000000..876ea6cb3d
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_parser.h
@@ -0,0 +1,177 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#ifndef CORE_FPDFAPI_PARSER_CPDF_PARSER_H_
+#define CORE_FPDFAPI_PARSER_CPDF_PARSER_H_
+
+#include <map>
+#include <memory>
+#include <set>
+
+#include "core/fxcrt/fx_basic.h"
+
+class CPDF_Array;
+class CPDF_CryptoHandler;
+class CPDF_Dictionary;
+class CPDF_Document;
+class CPDF_IndirectObjectHolder;
+class CPDF_Object;
+class CPDF_SecurityHandler;
+class CPDF_StreamAcc;
+class CPDF_SyntaxParser;
+class IFX_FileRead;
+
+class CPDF_Parser {
+ public:
+  enum Error {
+    SUCCESS = 0,
+    FILE_ERROR,
+    FORMAT_ERROR,
+    PASSWORD_ERROR,
+    HANDLER_ERROR
+  };
+
+  // A limit on the maximum object number in the xref table. Theoretical limits
+  // are higher, but this may be large enough in practice.
+  static const uint32_t kMaxObjectNumber = 1048576;
+
+  CPDF_Parser();
+  ~CPDF_Parser();
+
+  Error StartParse(IFX_FileRead* pFile, CPDF_Document* pDocument);
+  Error StartLinearizedParse(IFX_FileRead* pFile, CPDF_Document* pDocument);
+
+  void SetPassword(const FX_CHAR* password) { m_Password = password; }
+  CFX_ByteString GetPassword() { return m_Password; }
+  CPDF_Dictionary* GetTrailer() const { return m_pTrailer; }
+  FX_FILESIZE GetLastXRefOffset() const { return m_LastXRefOffset; }
+
+  uint32_t GetPermissions() const;
+  uint32_t GetRootObjNum();
+  uint32_t GetInfoObjNum();
+  CPDF_Array* GetIDArray();
+
+  CPDF_Dictionary* GetEncryptDict() const { return m_pEncryptDict; }
+
+  CPDF_Object* ParseIndirectObject(CPDF_IndirectObjectHolder* pObjList,
+                                   uint32_t objnum);
+
+  uint32_t GetLastObjNum() const;
+  bool IsValidObjectNumber(uint32_t objnum) const;
+  FX_FILESIZE GetObjectPositionOrZero(uint32_t objnum) const;
+  uint8_t GetObjectType(uint32_t objnum) const;
+  uint16_t GetObjectGenNum(uint32_t objnum) const;
+  bool IsVersionUpdated() const { return m_bVersionUpdated; }
+  bool IsObjectFreeOrNull(uint32_t objnum) const;
+  CPDF_CryptoHandler* GetCryptoHandler();
+  IFX_FileRead* GetFileAccess() const;
+
+  FX_FILESIZE GetObjectOffset(uint32_t objnum) const;
+  FX_FILESIZE GetObjectSize(uint32_t objnum) const;
+
+  void GetIndirectBinary(uint32_t objnum, uint8_t*& pBuffer, uint32_t& size);
+  int GetFileVersion() const { return m_FileVersion; }
+  FX_BOOL IsXRefStream() const { return m_bXRefStream; }
+
+  CPDF_Object* ParseIndirectObjectAt(CPDF_IndirectObjectHolder* pObjList,
+                                     FX_FILESIZE pos,
+                                     uint32_t objnum);
+
+  CPDF_Object* ParseIndirectObjectAtByStrict(
+      CPDF_IndirectObjectHolder* pObjList,
+      FX_FILESIZE pos,
+      uint32_t objnum,
+      FX_FILESIZE* pResultPos);
+
+  uint32_t GetFirstPageNo() const { return m_dwFirstPageNo; }
+
+ protected:
+  struct ObjectInfo {
+    ObjectInfo() : pos(0), type(0), gennum(0) {}
+
+    FX_FILESIZE pos;
+    uint8_t type;
+    uint16_t gennum;
+  };
+
+  std::unique_ptr<CPDF_SyntaxParser> m_pSyntax;
+  std::map<uint32_t, ObjectInfo> m_ObjectInfo;
+
+  bool LoadCrossRefV4(FX_FILESIZE pos, FX_FILESIZE streampos, FX_BOOL bSkip);
+  FX_BOOL RebuildCrossRef();
+
+ private:
+  friend class CPDF_DataAvail;
+
+  enum class ParserState {
+    kDefault,
+    kComment,
+    kWhitespace,
+    kString,
+    kHexString,
+    kEscapedString,
+    kXref,
+    kObjNum,
+    kPostObjNum,
+    kGenNum,
+    kPostGenNum,
+    kTrailer,
+    kBeginObj,
+    kEndObj
+  };
+
+  CPDF_Object* ParseDirect(CPDF_Object* pObj);
+  FX_BOOL LoadAllCrossRefV4(FX_FILESIZE pos);
+  FX_BOOL LoadAllCrossRefV5(FX_FILESIZE pos);
+  FX_BOOL LoadCrossRefV5(FX_FILESIZE* pos, FX_BOOL bMainXRef);
+  CPDF_Dictionary* LoadTrailerV4();
+  Error SetEncryptHandler();
+  void ReleaseEncryptHandler();
+  FX_BOOL LoadLinearizedAllCrossRefV4(FX_FILESIZE pos, uint32_t dwObjCount);
+  FX_BOOL LoadLinearizedCrossRefV4(FX_FILESIZE pos, uint32_t dwObjCount);
+  FX_BOOL LoadLinearizedAllCrossRefV5(FX_FILESIZE pos);
+  Error LoadLinearizedMainXRefTable();
+  CPDF_StreamAcc* GetObjectStream(uint32_t number);
+  FX_BOOL IsLinearizedFile(IFX_FileRead* pFileAccess, uint32_t offset);
+  void SetEncryptDictionary(CPDF_Dictionary* pDict);
+  void ShrinkObjectMap(uint32_t size);
+  // A simple check whether the cross reference table matches with
+  // the objects.
+  bool VerifyCrossRefV4();
+
+  CPDF_Document* m_pDocument;  // not owned
+  bool m_bHasParsed;
+  bool m_bOwnFileRead;
+  int m_FileVersion;
+  CPDF_Dictionary* m_pTrailer;
+  CPDF_Dictionary* m_pEncryptDict;
+  FX_FILESIZE m_LastXRefOffset;
+  FX_BOOL m_bXRefStream;
+  std::unique_ptr<CPDF_SecurityHandler> m_pSecurityHandler;
+  CFX_ByteString m_Password;
+  std::set<FX_FILESIZE> m_SortedOffset;
+  CFX_ArrayTemplate<CPDF_Dictionary*> m_Trailers;
+  bool m_bVersionUpdated;
+  CPDF_Object* m_pLinearized;
+  uint32_t m_dwFirstPageNo;
+  uint32_t m_dwXrefStartObjNum;
+
+  // A map of object numbers to indirect streams. Map owns the streams.
+  std::map<uint32_t, std::unique_ptr<CPDF_StreamAcc>> m_ObjectStreamMap;
+
+  // Mapping of object numbers to offsets. The offsets are relative to the first
+  // object in the stream.
+  using StreamObjectCache = std::map<uint32_t, uint32_t>;
+
+  // Mapping of streams to their object caches. This is valid as long as the
+  // streams in |m_ObjectStreamMap| are valid.
+  std::map<CPDF_StreamAcc*, StreamObjectCache> m_ObjCache;
+
+  // All indirect object numbers that are being parsed.
+  std::set<uint32_t> m_ParsingObjNums;
+};
+
+#endif  // CORE_FPDFAPI_PARSER_CPDF_PARSER_H_
diff --git a/core/fpdfapi/parser/cpdf_parser_embeddertest.cpp b/core/fpdfapi/parser/cpdf_parser_embeddertest.cpp
new file mode 100644
index 0000000000..f523d6b31b
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_parser_embeddertest.cpp
@@ -0,0 +1,59 @@
+// Copyright 2015 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "public/fpdf_text.h"
+#include "testing/embedder_test.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+class CPDFParserEmbeddertest : public EmbedderTest {};
+
+TEST_F(CPDFParserEmbeddertest, LoadError_454695) {
+  // Test a dictionary with hex string instead of correct content.
+  // Verify that the defective pdf shouldn't be opened correctly.
+  EXPECT_FALSE(OpenDocument("bug_454695.pdf"));
+}
+
+TEST_F(CPDFParserEmbeddertest, Bug_481363) {
+  // Test colorspace object with malformed dictionary.
+  EXPECT_TRUE(OpenDocument("bug_481363.pdf"));
+  FPDF_PAGE page = LoadPage(0);
+  EXPECT_NE(nullptr, page);
+  UnloadPage(page);
+}
+
+TEST_F(CPDFParserEmbeddertest, Bug_544880) {
+  // Test self referencing /Pages object.
+  EXPECT_TRUE(OpenDocument("bug_544880.pdf"));
+  // Shouldn't crash. We don't check the return value here because we get the
+  // the count from the "/Count 1" in the testcase (at the time of writing)
+  // rather than the actual count (0).
+  (void)GetPageCount();
+}
+
+TEST_F(CPDFParserEmbeddertest, Feature_Linearized_Loading) {
+  EXPECT_TRUE(OpenDocument("feature_linearized_loading.pdf", nullptr, true));
+}
+
+TEST_F(CPDFParserEmbeddertest, Bug_325a) {
+  EXPECT_FALSE(OpenDocument("bug_325_a.pdf"));
+}
+
+TEST_F(CPDFParserEmbeddertest, Bug_325b) {
+  EXPECT_FALSE(OpenDocument("bug_325_b.pdf"));
+}
+
+TEST_F(CPDFParserEmbeddertest, Bug_602650) {
+  // Test the case that cross reference entries, which are well formed,
+  // but do not match with the objects.
+  EXPECT_TRUE(OpenDocument("bug_602650.pdf"));
+  FPDF_PAGE page = LoadPage(0);
+  EXPECT_NE(nullptr, page);
+  FPDF_TEXTPAGE text_page = FPDFText_LoadPage(page);
+  EXPECT_NE(nullptr, text_page);
+  // The page should not be blank.
+  EXPECT_LT(0, FPDFText_CountChars(text_page));
+
+  FPDFText_ClosePage(text_page);
+  UnloadPage(page);
+}
diff --git a/core/fpdfapi/parser/cpdf_parser_unittest.cpp b/core/fpdfapi/parser/cpdf_parser_unittest.cpp
new file mode 100644
index 0000000000..c97b88e6d1
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_parser_unittest.cpp
@@ -0,0 +1,202 @@
+// Copyright 2015 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <limits>
+#include <string>
+
+#include "core/fpdfapi/parser/cpdf_parser.h"
+#include "core/fpdfapi/parser/cpdf_syntax_parser.h"
+#include "core/fxcrt/fx_ext.h"
+#include "core/fxcrt/fx_stream.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "testing/utils/path_service.h"
+
+// Provide a way to read test data from a buffer instead of a file.
+class CFX_TestBufferRead : public IFX_FileRead {
+ public:
+  CFX_TestBufferRead(const unsigned char* buffer_in, size_t buf_size)
+      : buffer_(buffer_in), total_size_(buf_size) {}
+
+  // IFX_Stream
+  void Release() override { delete this; }
+
+  // IFX_FileRead
+  FX_BOOL ReadBlock(void* buffer, FX_FILESIZE offset, size_t size) override {
+    if (offset < 0 || offset + size > total_size_) {
+      return FALSE;
+    }
+
+    memcpy(buffer, buffer_ + offset, size);
+    return TRUE;
+  }
+  FX_FILESIZE GetSize() override { return (FX_FILESIZE)total_size_; };
+
+ protected:
+  const unsigned char* buffer_;
+  size_t total_size_;
+};
+
+// A wrapper class to help test member functions of CPDF_Parser.
+class CPDF_TestParser : public CPDF_Parser {
+ public:
+  CPDF_TestParser() {}
+  ~CPDF_TestParser() {}
+
+  // Setup reading from a file and initial states.
+  bool InitTestFromFile(const FX_CHAR* path) {
+    IFX_FileRead* pFileAccess = FX_CreateFileRead(path);
+    if (!pFileAccess)
+      return false;
+
+    // For the test file, the header is set at the beginning.
+    m_pSyntax->InitParser(pFileAccess, 0);
+    return true;
+  }
+
+  // Setup reading from a buffer and initial states.
+  bool InitTestFromBuffer(const unsigned char* buffer, size_t len) {
+    CFX_TestBufferRead* buffer_reader = new CFX_TestBufferRead(buffer, len);
+
+    // For the test file, the header is set at the beginning.
+    m_pSyntax->InitParser(buffer_reader, 0);
+    return true;
+  }
+
+ private:
+  // Add test cases here as private friend so that protected members in
+  // CPDF_Parser can be accessed by test cases.
+  // Need to access RebuildCrossRef.
+  FRIEND_TEST(cpdf_parser, RebuildCrossRefCorrectly);
+  FRIEND_TEST(cpdf_parser, RebuildCrossRefFailed);
+  // Need to access LoadCrossRefV4.
+  FRIEND_TEST(cpdf_parser, LoadCrossRefV4);
+};
+
+TEST(cpdf_parser, RebuildCrossRefCorrectly) {
+  CPDF_TestParser parser;
+  std::string test_file;
+  ASSERT_TRUE(PathService::GetTestFilePath("parser_rebuildxref_correct.pdf",
+                                           &test_file));
+  ASSERT_TRUE(parser.InitTestFromFile(test_file.c_str())) << test_file;
+
+  ASSERT_TRUE(parser.RebuildCrossRef());
+  const FX_FILESIZE offsets[] = {0, 15, 61, 154, 296, 374, 450};
+  const uint16_t versions[] = {0, 0, 2, 4, 6, 8, 0};
+  for (size_t i = 0; i < FX_ArraySize(offsets); ++i)
+    EXPECT_EQ(offsets[i], parser.m_ObjectInfo[i].pos);
+  for (size_t i = 0; i < FX_ArraySize(versions); ++i)
+    EXPECT_EQ(versions[i], parser.m_ObjectInfo[i].gennum);
+}
+
+TEST(cpdf_parser, RebuildCrossRefFailed) {
+  CPDF_TestParser parser;
+  std::string test_file;
+  ASSERT_TRUE(PathService::GetTestFilePath(
+      "parser_rebuildxref_error_notrailer.pdf", &test_file));
+  ASSERT_TRUE(parser.InitTestFromFile(test_file.c_str())) << test_file;
+
+  ASSERT_FALSE(parser.RebuildCrossRef());
+}
+
+TEST(cpdf_parser, LoadCrossRefV4) {
+  {
+    const unsigned char xref_table[] =
+        "xref \n"
+        "0 6 \n"
+        "0000000003 65535 f \n"
+        "0000000017 00000 n \n"
+        "0000000081 00000 n \n"
+        "0000000000 00007 f \n"
+        "0000000331 00000 n \n"
+        "0000000409 00000 n \n"
+        "trail";  // Needed to end cross ref table reading.
+    CPDF_TestParser parser;
+    ASSERT_TRUE(
+        parser.InitTestFromBuffer(xref_table, FX_ArraySize(xref_table)));
+
+    ASSERT_TRUE(parser.LoadCrossRefV4(0, 0, FALSE));
+    const FX_FILESIZE offsets[] = {0, 17, 81, 0, 331, 409};
+    const uint8_t types[] = {0, 1, 1, 0, 1, 1};
+    for (size_t i = 0; i < FX_ArraySize(offsets); ++i) {
+      EXPECT_EQ(offsets[i], parser.m_ObjectInfo[i].pos);
+      EXPECT_EQ(types[i], parser.m_ObjectInfo[i].type);
+    }
+  }
+  {
+    const unsigned char xref_table[] =
+        "xref \n"
+        "0 1 \n"
+        "0000000000 65535 f \n"
+        "3 1 \n"
+        "0000025325 00000 n \n"
+        "8 2 \n"
+        "0000025518 00002 n \n"
+        "0000025635 00000 n \n"
+        "12 1 \n"
+        "0000025777 00000 n \n"
+        "trail";  // Needed to end cross ref table reading.
+    CPDF_TestParser parser;
+    ASSERT_TRUE(
+        parser.InitTestFromBuffer(xref_table, FX_ArraySize(xref_table)));
+
+    ASSERT_TRUE(parser.LoadCrossRefV4(0, 0, FALSE));
+    const FX_FILESIZE offsets[] = {0, 0,     0,     25325, 0, 0,    0,
+                                   0, 25518, 25635, 0,     0, 25777};
+    const uint8_t types[] = {0, 0, 0, 1, 0, 0, 0, 0, 1, 1, 0, 0, 1};
+    for (size_t i = 0; i < FX_ArraySize(offsets); ++i) {
+      EXPECT_EQ(offsets[i], parser.m_ObjectInfo[i].pos);
+      EXPECT_EQ(types[i], parser.m_ObjectInfo[i].type);
+    }
+  }
+  {
+    const unsigned char xref_table[] =
+        "xref \n"
+        "0 1 \n"
+        "0000000000 65535 f \n"
+        "3 1 \n"
+        "0000025325 00000 n \n"
+        "8 2 \n"
+        "0000000000 65535 f \n"
+        "0000025635 00000 n \n"
+        "12 1 \n"
+        "0000025777 00000 n \n"
+        "trail";  // Needed to end cross ref table reading.
+    CPDF_TestParser parser;
+    ASSERT_TRUE(
+        parser.InitTestFromBuffer(xref_table, FX_ArraySize(xref_table)));
+
+    ASSERT_TRUE(parser.LoadCrossRefV4(0, 0, FALSE));
+    const FX_FILESIZE offsets[] = {0, 0, 0,     25325, 0, 0,    0,
+                                   0, 0, 25635, 0,     0, 25777};
+    const uint8_t types[] = {0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 1};
+    for (size_t i = 0; i < FX_ArraySize(offsets); ++i) {
+      EXPECT_EQ(offsets[i], parser.m_ObjectInfo[i].pos);
+      EXPECT_EQ(types[i], parser.m_ObjectInfo[i].type);
+    }
+  }
+  {
+    const unsigned char xref_table[] =
+        "xref \n"
+        "0 7 \n"
+        "0000000002 65535 f \n"
+        "0000000023 00000 n \n"
+        "0000000003 65535 f \n"
+        "0000000004 65535 f \n"
+        "0000000000 65535 f \n"
+        "0000000045 00000 n \n"
+        "0000000179 00000 n \n"
+        "trail";  // Needed to end cross ref table reading.
+    CPDF_TestParser parser;
+    ASSERT_TRUE(
+        parser.InitTestFromBuffer(xref_table, FX_ArraySize(xref_table)));
+
+    ASSERT_TRUE(parser.LoadCrossRefV4(0, 0, FALSE));
+    const FX_FILESIZE offsets[] = {0, 23, 0, 0, 0, 45, 179};
+    const uint8_t types[] = {0, 1, 0, 0, 0, 1, 1};
+    for (size_t i = 0; i < FX_ArraySize(offsets); ++i) {
+      EXPECT_EQ(offsets[i], parser.m_ObjectInfo[i].pos);
+      EXPECT_EQ(types[i], parser.m_ObjectInfo[i].type);
+    }
+  }
+}
diff --git a/core/fpdfapi/parser/cpdf_reference.cpp b/core/fpdfapi/parser/cpdf_reference.cpp
new file mode 100644
index 0000000000..a9cdf54855
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_reference.cpp
@@ -0,0 +1,83 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#include "core/fpdfapi/parser/cpdf_reference.h"
+
+#include "core/fpdfapi/parser/cpdf_indirect_object_holder.h"
+#include "third_party/base/stl_util.h"
+
+CPDF_Reference::CPDF_Reference(CPDF_IndirectObjectHolder* pDoc, int objnum)
+    : m_pObjList(pDoc), m_RefObjNum(objnum) {}
+
+CPDF_Reference::~CPDF_Reference() {}
+
+CPDF_Object::Type CPDF_Reference::GetType() const {
+  return REFERENCE;
+}
+
+CFX_ByteString CPDF_Reference::GetString() const {
+  CPDF_Object* obj = SafeGetDirect();
+  return obj ? obj->GetString() : CFX_ByteString();
+}
+
+FX_FLOAT CPDF_Reference::GetNumber() const {
+  CPDF_Object* obj = SafeGetDirect();
+  return obj ? obj->GetNumber() : 0;
+}
+
+int CPDF_Reference::GetInteger() const {
+  CPDF_Object* obj = SafeGetDirect();
+  return obj ? obj->GetInteger() : 0;
+}
+
+CPDF_Dictionary* CPDF_Reference::GetDict() const {
+  CPDF_Object* obj = SafeGetDirect();
+  return obj ? obj->GetDict() : nullptr;
+}
+
+bool CPDF_Reference::IsReference() const {
+  return true;
+}
+
+CPDF_Reference* CPDF_Reference::AsReference() {
+  return this;
+}
+
+const CPDF_Reference* CPDF_Reference::AsReference() const {
+  return this;
+}
+
+CPDF_Object* CPDF_Reference::Clone() const {
+  return CloneObjectNonCyclic(false);
+}
+
+CPDF_Object* CPDF_Reference::CloneNonCyclic(
+    bool bDirect,
+    std::set<const CPDF_Object*>* pVisited) const {
+  pVisited->insert(this);
+  if (bDirect) {
+    auto* pDirect = GetDirect();
+    return pDirect && !pdfium::ContainsKey(*pVisited, pDirect)
+               ? pDirect->CloneNonCyclic(true, pVisited)
+               : nullptr;
+  }
+  return new CPDF_Reference(m_pObjList, m_RefObjNum);
+}
+
+CPDF_Object* CPDF_Reference::SafeGetDirect() const {
+  CPDF_Object* obj = GetDirect();
+  return (obj && !obj->IsReference()) ? obj : nullptr;
+}
+
+void CPDF_Reference::SetRef(CPDF_IndirectObjectHolder* pDoc, uint32_t objnum) {
+  m_pObjList = pDoc;
+  m_RefObjNum = objnum;
+}
+
+CPDF_Object* CPDF_Reference::GetDirect() const {
+  return m_pObjList ? m_pObjList->GetOrParseIndirectObject(m_RefObjNum)
+                    : nullptr;
+}
diff --git a/core/fpdfapi/parser/cpdf_reference.h b/core/fpdfapi/parser/cpdf_reference.h
new file mode 100644
index 0000000000..8c57d85e0e
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_reference.h
@@ -0,0 +1,50 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#ifndef CORE_FPDFAPI_PARSER_CPDF_REFERENCE_H_
+#define CORE_FPDFAPI_PARSER_CPDF_REFERENCE_H_
+
+#include <set>
+
+#include "core/fpdfapi/parser/cpdf_object.h"
+
+class CPDF_IndirectObjectHolder;
+
+class CPDF_Reference : public CPDF_Object {
+ public:
+  CPDF_Reference(CPDF_IndirectObjectHolder* pDoc, int objnum);
+
+  // CPDF_Object.
+  Type GetType() const override;
+  CPDF_Object* Clone() const override;
+  CPDF_Object* GetDirect() const override;
+  CFX_ByteString GetString() const override;
+  FX_FLOAT GetNumber() const override;
+  int GetInteger() const override;
+  CPDF_Dictionary* GetDict() const override;
+  bool IsReference() const override;
+  CPDF_Reference* AsReference() override;
+  const CPDF_Reference* AsReference() const override;
+
+  CPDF_IndirectObjectHolder* GetObjList() const { return m_pObjList; }
+  uint32_t GetRefObjNum() const { return m_RefObjNum; }
+
+  void SetRef(CPDF_IndirectObjectHolder* pDoc, uint32_t objnum);
+
+ protected:
+  ~CPDF_Reference() override;
+
+  CPDF_Object* CloneNonCyclic(
+      bool bDirect,
+      std::set<const CPDF_Object*>* pVisited) const override;
+
+  CPDF_Object* SafeGetDirect() const;
+
+  CPDF_IndirectObjectHolder* m_pObjList;
+  uint32_t m_RefObjNum;
+};
+
+#endif  // CORE_FPDFAPI_PARSER_CPDF_REFERENCE_H_
diff --git a/core/fpdfapi/parser/cpdf_security_handler.cpp b/core/fpdfapi/parser/cpdf_security_handler.cpp
new file mode 100644
index 0000000000..039ba4e1ab
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_security_handler.cpp
@@ -0,0 +1,699 @@
+// Copyright 2014 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#include "core/fpdfapi/parser/cpdf_security_handler.h"
+
+#include <time.h>
+
+#include "core/fdrm/crypto/fx_crypt.h"
+#include "core/fpdfapi/parser/cpdf_array.h"
+#include "core/fpdfapi/parser/cpdf_crypto_handler.h"
+#include "core/fpdfapi/parser/cpdf_dictionary.h"
+#include "core/fpdfapi/parser/cpdf_object.h"
+#include "core/fpdfapi/parser/cpdf_parser.h"
+
+namespace {
+
+const uint8_t defpasscode[32] = {
+    0x28, 0xbf, 0x4e, 0x5e, 0x4e, 0x75, 0x8a, 0x41, 0x64, 0x00, 0x4e,
+    0x56, 0xff, 0xfa, 0x01, 0x08, 0x2e, 0x2e, 0x00, 0xb6, 0xd0, 0x68,
+    0x3e, 0x80, 0x2f, 0x0c, 0xa9, 0xfe, 0x64, 0x53, 0x69, 0x7a};
+
+void CalcEncryptKey(CPDF_Dictionary* pEncrypt,
+                    const uint8_t* password,
+                    uint32_t pass_size,
+                    uint8_t* key,
+                    int keylen,
+                    FX_BOOL bIgnoreMeta,
+                    CPDF_Array* pIdArray) {
+  int revision = pEncrypt->GetIntegerFor("R");
+  uint8_t passcode[32];
+  for (uint32_t i = 0; i < 32; i++) {
+    passcode[i] = i < pass_size ? password[i] : defpasscode[i - pass_size];
+  }
+  uint8_t md5[100];
+  CRYPT_MD5Start(md5);
+  CRYPT_MD5Update(md5, passcode, 32);
+  CFX_ByteString okey = pEncrypt->GetStringFor("O");
+  CRYPT_MD5Update(md5, (uint8_t*)okey.c_str(), okey.GetLength());
+  uint32_t perm = pEncrypt->GetIntegerFor("P");
+  CRYPT_MD5Update(md5, (uint8_t*)&perm, 4);
+  if (pIdArray) {
+    CFX_ByteString id = pIdArray->GetStringAt(0);
+    CRYPT_MD5Update(md5, (uint8_t*)id.c_str(), id.GetLength());
+  }
+  if (!bIgnoreMeta && revision >= 3 &&
+      !pEncrypt->GetIntegerFor("EncryptMetadata", 1)) {
+    uint32_t tag = (uint32_t)-1;
+    CRYPT_MD5Update(md5, (uint8_t*)&tag, 4);
+  }
+  uint8_t digest[16];
+  CRYPT_MD5Finish(md5, digest);
+  uint32_t copy_len = keylen;
+  if (copy_len > sizeof(digest)) {
+    copy_len = sizeof(digest);
+  }
+  if (revision >= 3) {
+    for (int i = 0; i < 50; i++) {
+      CRYPT_MD5Generate(digest, copy_len, digest);
+    }
+  }
+  FXSYS_memset(key, 0, keylen);
+  FXSYS_memcpy(key, digest, copy_len);
+}
+
+}  // namespace
+
+CPDF_SecurityHandler::CPDF_SecurityHandler()
+    : m_Version(0),
+      m_Revision(0),
+      m_pParser(nullptr),
+      m_pEncryptDict(nullptr),
+      m_Permissions(0),
+      m_Cipher(FXCIPHER_NONE),
+      m_KeyLen(0),
+      m_bOwnerUnlocked(false) {}
+
+CPDF_SecurityHandler::~CPDF_SecurityHandler() {}
+
+CPDF_CryptoHandler* CPDF_SecurityHandler::CreateCryptoHandler() {
+  return new CPDF_CryptoHandler;
+}
+
+FX_BOOL CPDF_SecurityHandler::OnInit(CPDF_Parser* pParser,
+                                     CPDF_Dictionary* pEncryptDict) {
+  m_pParser = pParser;
+  if (!LoadDict(pEncryptDict)) {
+    return FALSE;
+  }
+  if (m_Cipher == FXCIPHER_NONE) {
+    return TRUE;
+  }
+  return CheckSecurity(m_KeyLen);
+}
+
+FX_BOOL CPDF_SecurityHandler::CheckSecurity(int32_t key_len) {
+  CFX_ByteString password = m_pParser->GetPassword();
+  if (!password.IsEmpty() &&
+      CheckPassword(password.raw_str(), password.GetLength(), TRUE,
+                    m_EncryptKey, key_len)) {
+    m_bOwnerUnlocked = true;
+    return TRUE;
+  }
+  return CheckPassword(password.raw_str(), password.GetLength(), FALSE,
+                       m_EncryptKey, key_len);
+}
+
+uint32_t CPDF_SecurityHandler::GetPermissions() {
+  return m_bOwnerUnlocked ? 0xFFFFFFFF : m_Permissions;
+}
+
+static FX_BOOL LoadCryptInfo(CPDF_Dictionary* pEncryptDict,
+                             const CFX_ByteString& name,
+                             int& cipher,
+                             int& keylen) {
+  int Version = pEncryptDict->GetIntegerFor("V");
+  cipher = FXCIPHER_RC4;
+  keylen = 0;
+  if (Version >= 4) {
+    CPDF_Dictionary* pCryptFilters = pEncryptDict->GetDictFor("CF");
+    if (!pCryptFilters) {
+      return FALSE;
+    }
+    if (name == "Identity") {
+      cipher = FXCIPHER_NONE;
+    } else {
+      CPDF_Dictionary* pDefFilter = pCryptFilters->GetDictFor(name);
+      if (!pDefFilter) {
+        return FALSE;
+      }
+      int nKeyBits = 0;
+      if (Version == 4) {
+        nKeyBits = pDefFilter->GetIntegerFor("Length", 0);
+        if (nKeyBits == 0) {
+          nKeyBits = pEncryptDict->GetIntegerFor("Length", 128);
+        }
+      } else {
+        nKeyBits = pEncryptDict->GetIntegerFor("Length", 256);
+      }
+      if (nKeyBits < 40) {
+        nKeyBits *= 8;
+      }
+      keylen = nKeyBits / 8;
+      CFX_ByteString cipher_name = pDefFilter->GetStringFor("CFM");
+      if (cipher_name == "AESV2" || cipher_name == "AESV3") {
+        cipher = FXCIPHER_AES;
+      }
+    }
+  } else {
+    keylen = Version > 1 ? pEncryptDict->GetIntegerFor("Length", 40) / 8 : 5;
+  }
+  if (keylen > 32 || keylen < 0) {
+    return FALSE;
+  }
+  return TRUE;
+}
+
+FX_BOOL CPDF_SecurityHandler::LoadDict(CPDF_Dictionary* pEncryptDict) {
+  m_pEncryptDict = pEncryptDict;
+  m_Version = pEncryptDict->GetIntegerFor("V");
+  m_Revision = pEncryptDict->GetIntegerFor("R");
+  m_Permissions = pEncryptDict->GetIntegerFor("P", -1);
+  if (m_Version < 4)
+    return LoadCryptInfo(pEncryptDict, CFX_ByteString(), m_Cipher, m_KeyLen);
+
+  CFX_ByteString stmf_name = pEncryptDict->GetStringFor("StmF");
+  CFX_ByteString strf_name = pEncryptDict->GetStringFor("StrF");
+  if (stmf_name != strf_name)
+    return FALSE;
+
+  return LoadCryptInfo(pEncryptDict, strf_name, m_Cipher, m_KeyLen);
+}
+
+FX_BOOL CPDF_SecurityHandler::LoadDict(CPDF_Dictionary* pEncryptDict,
+                                       uint32_t type,
+                                       int& cipher,
+                                       int& key_len) {
+  m_pEncryptDict = pEncryptDict;
+  m_Version = pEncryptDict->GetIntegerFor("V");
+  m_Revision = pEncryptDict->GetIntegerFor("R");
+  m_Permissions = pEncryptDict->GetIntegerFor("P", -1);
+
+  CFX_ByteString strf_name;
+  CFX_ByteString stmf_name;
+  if (m_Version >= 4) {
+    stmf_name = pEncryptDict->GetStringFor("StmF");
+    strf_name = pEncryptDict->GetStringFor("StrF");
+    if (stmf_name != strf_name)
+      return FALSE;
+  }
+  if (!LoadCryptInfo(pEncryptDict, strf_name, cipher, key_len))
+    return FALSE;
+
+  m_Cipher = cipher;
+  m_KeyLen = key_len;
+  return TRUE;
+}
+
+FX_BOOL CPDF_SecurityHandler::GetCryptInfo(int& cipher,
+                                           const uint8_t*& buffer,
+                                           int& keylen) {
+  cipher = m_Cipher;
+  buffer = m_EncryptKey;
+  keylen = m_KeyLen;
+  return TRUE;
+}
+#define FX_GET_32WORD(n, b, i)                                        \
+  {                                                                   \
+    (n) = (uint32_t)(                                                 \
+        ((uint64_t)(b)[(i)] << 24) | ((uint64_t)(b)[(i) + 1] << 16) | \
+        ((uint64_t)(b)[(i) + 2] << 8) | ((uint64_t)(b)[(i) + 3]));    \
+  }
+int BigOrder64BitsMod3(uint8_t* data) {
+  uint64_t ret = 0;
+  for (int i = 0; i < 4; ++i) {
+    uint32_t value;
+    FX_GET_32WORD(value, data, 4 * i);
+    ret <<= 32;
+    ret |= value;
+    ret %= 3;
+  }
+  return (int)ret;
+}
+void Revision6_Hash(const uint8_t* password,
+                    uint32_t size,
+                    const uint8_t* salt,
+                    const uint8_t* vector,
+                    uint8_t* hash) {
+  int iBlockSize = 32;
+  uint8_t sha[128];
+  CRYPT_SHA256Start(sha);
+  CRYPT_SHA256Update(sha, password, size);
+  CRYPT_SHA256Update(sha, salt, 8);
+  if (vector) {
+    CRYPT_SHA256Update(sha, vector, 48);
+  }
+  uint8_t digest[32];
+  CRYPT_SHA256Finish(sha, digest);
+  CFX_ByteTextBuf buf;
+  uint8_t* input = digest;
+  uint8_t* key = input;
+  uint8_t* iv = input + 16;
+  uint8_t* E = buf.GetBuffer();
+  int iBufLen = buf.GetLength();
+  CFX_ByteTextBuf interDigest;
+  int i = 0;
+  uint8_t* aes = FX_Alloc(uint8_t, 2048);
+  while (i < 64 || i < E[iBufLen - 1] + 32) {
+    int iRoundSize = size + iBlockSize;
+    if (vector) {
+      iRoundSize += 48;
+    }
+    iBufLen = iRoundSize * 64;
+    buf.EstimateSize(iBufLen);
+    E = buf.GetBuffer();
+    CFX_ByteTextBuf content;
+    for (int j = 0; j < 64; ++j) {
+      content.AppendBlock(password, size);
+      content.AppendBlock(input, iBlockSize);
+      if (vector) {
+        content.AppendBlock(vector, 48);
+      }
+    }
+    CRYPT_AESSetKey(aes, 16, key, 16, TRUE);
+    CRYPT_AESSetIV(aes, iv);
+    CRYPT_AESEncrypt(aes, E, content.GetBuffer(), iBufLen);
+    int iHash = 0;
+    switch (BigOrder64BitsMod3(E)) {
+      case 0:
+        iHash = 0;
+        iBlockSize = 32;
+        break;
+      case 1:
+        iHash = 1;
+        iBlockSize = 48;
+        break;
+      default:
+        iHash = 2;
+        iBlockSize = 64;
+        break;
+    }
+    interDigest.EstimateSize(iBlockSize);
+    input = interDigest.GetBuffer();
+    if (iHash == 0) {
+      CRYPT_SHA256Generate(E, iBufLen, input);
+    } else if (iHash == 1) {
+      CRYPT_SHA384Generate(E, iBufLen, input);
+    } else if (iHash == 2) {
+      CRYPT_SHA512Generate(E, iBufLen, input);
+    }
+    key = input;
+    iv = input + 16;
+    ++i;
+  }
+  FX_Free(aes);
+  if (hash) {
+    FXSYS_memcpy(hash, input, 32);
+  }
+}
+FX_BOOL CPDF_SecurityHandler::AES256_CheckPassword(const uint8_t* password,
+                                                   uint32_t size,
+                                                   FX_BOOL bOwner,
+                                                   uint8_t* key) {
+  CFX_ByteString okey =
+      m_pEncryptDict ? m_pEncryptDict->GetStringFor("O") : CFX_ByteString();
+  if (okey.GetLength() < 48) {
+    return FALSE;
+  }
+  CFX_ByteString ukey =
+      m_pEncryptDict ? m_pEncryptDict->GetStringFor("U") : CFX_ByteString();
+  if (ukey.GetLength() < 48) {
+    return FALSE;
+  }
+  const uint8_t* pkey = (bOwner ? okey : ukey).raw_str();
+  uint8_t sha[128];
+  uint8_t digest[32];
+  if (m_Revision >= 6) {
+    Revision6_Hash(password, size, (const uint8_t*)pkey + 32,
+                   bOwner ? ukey.raw_str() : nullptr, digest);
+  } else {
+    CRYPT_SHA256Start(sha);
+    CRYPT_SHA256Update(sha, password, size);
+    CRYPT_SHA256Update(sha, pkey + 32, 8);
+    if (bOwner) {
+      CRYPT_SHA256Update(sha, ukey.raw_str(), 48);
+    }
+    CRYPT_SHA256Finish(sha, digest);
+  }
+  if (FXSYS_memcmp(digest, pkey, 32) != 0) {
+    return FALSE;
+  }
+  if (!key) {
+    return TRUE;
+  }
+  if (m_Revision >= 6) {
+    Revision6_Hash(password, size, (const uint8_t*)pkey + 40,
+                   bOwner ? ukey.raw_str() : nullptr, digest);
+  } else {
+    CRYPT_SHA256Start(sha);
+    CRYPT_SHA256Update(sha, password, size);
+    CRYPT_SHA256Update(sha, pkey + 40, 8);
+    if (bOwner) {
+      CRYPT_SHA256Update(sha, ukey.raw_str(), 48);
+    }
+    CRYPT_SHA256Finish(sha, digest);
+  }
+  CFX_ByteString ekey = m_pEncryptDict
+                            ? m_pEncryptDict->GetStringFor(bOwner ? "OE" : "UE")
+                            : CFX_ByteString();
+  if (ekey.GetLength() < 32) {
+    return FALSE;
+  }
+  uint8_t* aes = FX_Alloc(uint8_t, 2048);
+  CRYPT_AESSetKey(aes, 16, digest, 32, FALSE);
+  uint8_t iv[16];
+  FXSYS_memset(iv, 0, 16);
+  CRYPT_AESSetIV(aes, iv);
+  CRYPT_AESDecrypt(aes, key, ekey.raw_str(), 32);
+  CRYPT_AESSetKey(aes, 16, key, 32, FALSE);
+  CRYPT_AESSetIV(aes, iv);
+  CFX_ByteString perms = m_pEncryptDict->GetStringFor("Perms");
+  if (perms.IsEmpty()) {
+    return FALSE;
+  }
+  uint8_t perms_buf[16];
+  FXSYS_memset(perms_buf, 0, sizeof(perms_buf));
+  uint32_t copy_len = sizeof(perms_buf);
+  if (copy_len > (uint32_t)perms.GetLength()) {
+    copy_len = perms.GetLength();
+  }
+  FXSYS_memcpy(perms_buf, perms.raw_str(), copy_len);
+  uint8_t buf[16];
+  CRYPT_AESDecrypt(aes, buf, perms_buf, 16);
+  FX_Free(aes);
+  if (buf[9] != 'a' || buf[10] != 'd' || buf[11] != 'b') {
+    return FALSE;
+  }
+  if (FXDWORD_GET_LSBFIRST(buf) != m_Permissions) {
+    return FALSE;
+  }
+  if ((buf[8] == 'T' && !IsMetadataEncrypted()) ||
+      (buf[8] == 'F' && IsMetadataEncrypted())) {
+    return FALSE;
+  }
+  return TRUE;
+}
+
+int CPDF_SecurityHandler::CheckPassword(const uint8_t* password,
+                                        uint32_t size,
+                                        FX_BOOL bOwner,
+                                        uint8_t* key,
+                                        int32_t key_len) {
+  if (m_Revision >= 5) {
+    return AES256_CheckPassword(password, size, bOwner, key);
+  }
+  uint8_t keybuf[32];
+  if (!key) {
+    key = keybuf;
+  }
+  if (bOwner) {
+    return CheckOwnerPassword(password, size, key, key_len);
+  }
+  return CheckUserPassword(password, size, FALSE, key, key_len) ||
+         CheckUserPassword(password, size, TRUE, key, key_len);
+}
+FX_BOOL CPDF_SecurityHandler::CheckUserPassword(const uint8_t* password,
+                                                uint32_t pass_size,
+                                                FX_BOOL bIgnoreEncryptMeta,
+                                                uint8_t* key,
+                                                int32_t key_len) {
+  CalcEncryptKey(m_pEncryptDict, password, pass_size, key, key_len,
+                 bIgnoreEncryptMeta, m_pParser->GetIDArray());
+  CFX_ByteString ukey =
+      m_pEncryptDict ? m_pEncryptDict->GetStringFor("U") : CFX_ByteString();
+  if (ukey.GetLength() < 16) {
+    return FALSE;
+  }
+  uint8_t ukeybuf[32];
+  if (m_Revision == 2) {
+    FXSYS_memcpy(ukeybuf, defpasscode, 32);
+    CRYPT_ArcFourCryptBlock(ukeybuf, 32, key, key_len);
+  } else {
+    uint8_t test[32], tmpkey[32];
+    uint32_t copy_len = sizeof(test);
+    if (copy_len > (uint32_t)ukey.GetLength()) {
+      copy_len = ukey.GetLength();
+    }
+    FXSYS_memset(test, 0, sizeof(test));
+    FXSYS_memset(tmpkey, 0, sizeof(tmpkey));
+    FXSYS_memcpy(test, ukey.c_str(), copy_len);
+    for (int32_t i = 19; i >= 0; i--) {
+      for (int j = 0; j < key_len; j++)
+        tmpkey[j] = key[j] ^ static_cast<uint8_t>(i);
+      CRYPT_ArcFourCryptBlock(test, 32, tmpkey, key_len);
+    }
+    uint8_t md5[100];
+    CRYPT_MD5Start(md5);
+    CRYPT_MD5Update(md5, defpasscode, 32);
+    CPDF_Array* pIdArray = m_pParser->GetIDArray();
+    if (pIdArray) {
+      CFX_ByteString id = pIdArray->GetStringAt(0);
+      CRYPT_MD5Update(md5, (uint8_t*)id.c_str(), id.GetLength());
+    }
+    CRYPT_MD5Finish(md5, ukeybuf);
+    return FXSYS_memcmp(test, ukeybuf, 16) == 0;
+  }
+  if (FXSYS_memcmp((void*)ukey.c_str(), ukeybuf, 16) == 0) {
+    return TRUE;
+  }
+  return FALSE;
+}
+CFX_ByteString CPDF_SecurityHandler::GetUserPassword(const uint8_t* owner_pass,
+                                                     uint32_t pass_size,
+                                                     int32_t key_len) {
+  CFX_ByteString okey = m_pEncryptDict->GetStringFor("O");
+  uint8_t passcode[32];
+  for (uint32_t i = 0; i < 32; i++) {
+    passcode[i] = i < pass_size ? owner_pass[i] : defpasscode[i - pass_size];
+  }
+  uint8_t digest[16];
+  CRYPT_MD5Generate(passcode, 32, digest);
+  if (m_Revision >= 3) {
+    for (uint32_t i = 0; i < 50; i++) {
+      CRYPT_MD5Generate(digest, 16, digest);
+    }
+  }
+  uint8_t enckey[32];
+  FXSYS_memset(enckey, 0, sizeof(enckey));
+  uint32_t copy_len = key_len;
+  if (copy_len > sizeof(digest)) {
+    copy_len = sizeof(digest);
+  }
+  FXSYS_memcpy(enckey, digest, copy_len);
+  int okeylen = okey.GetLength();
+  if (okeylen > 32) {
+    okeylen = 32;
+  }
+  uint8_t okeybuf[64];
+  FXSYS_memset(okeybuf, 0, sizeof(okeybuf));
+  FXSYS_memcpy(okeybuf, okey.c_str(), okeylen);
+  if (m_Revision == 2) {
+    CRYPT_ArcFourCryptBlock(okeybuf, okeylen, enckey, key_len);
+  } else {
+    for (int32_t i = 19; i >= 0; i--) {
+      uint8_t tempkey[32];
+      FXSYS_memset(tempkey, 0, sizeof(tempkey));
+      for (int j = 0; j < m_KeyLen; j++)
+        tempkey[j] = enckey[j] ^ static_cast<uint8_t>(i);
+      CRYPT_ArcFourCryptBlock(okeybuf, okeylen, tempkey, key_len);
+    }
+  }
+  int len = 32;
+  while (len && defpasscode[len - 1] == okeybuf[len - 1]) {
+    len--;
+  }
+  return CFX_ByteString(okeybuf, len);
+}
+FX_BOOL CPDF_SecurityHandler::CheckOwnerPassword(const uint8_t* password,
+                                                 uint32_t pass_size,
+                                                 uint8_t* key,
+                                                 int32_t key_len) {
+  CFX_ByteString user_pass = GetUserPassword(password, pass_size, key_len);
+  if (CheckUserPassword(user_pass.raw_str(), user_pass.GetLength(), FALSE, key,
+                        key_len)) {
+    return TRUE;
+  }
+  return CheckUserPassword(user_pass.raw_str(), user_pass.GetLength(), TRUE,
+                           key, key_len);
+}
+
+bool CPDF_SecurityHandler::IsMetadataEncrypted() const {
+  return m_pEncryptDict->GetBooleanFor("EncryptMetadata", true);
+}
+
+void CPDF_SecurityHandler::OnCreate(CPDF_Dictionary* pEncryptDict,
+                                    CPDF_Array* pIdArray,
+                                    const uint8_t* user_pass,
+                                    uint32_t user_size,
+                                    const uint8_t* owner_pass,
+                                    uint32_t owner_size,
+                                    FX_BOOL bDefault,
+                                    uint32_t type) {
+  int cipher = 0, key_len = 0;
+  if (!LoadDict(pEncryptDict, type, cipher, key_len)) {
+    return;
+  }
+  if (bDefault && (!owner_pass || owner_size == 0)) {
+    owner_pass = user_pass;
+    owner_size = user_size;
+  }
+  if (m_Revision >= 5) {
+    int t = (int)time(nullptr);
+    uint8_t sha[128];
+    CRYPT_SHA256Start(sha);
+    CRYPT_SHA256Update(sha, (uint8_t*)&t, sizeof t);
+    CRYPT_SHA256Update(sha, m_EncryptKey, 32);
+    CRYPT_SHA256Update(sha, (uint8_t*)"there", 5);
+    CRYPT_SHA256Finish(sha, m_EncryptKey);
+    AES256_SetPassword(pEncryptDict, user_pass, user_size, FALSE, m_EncryptKey);
+    if (bDefault) {
+      AES256_SetPassword(pEncryptDict, owner_pass, owner_size, TRUE,
+                         m_EncryptKey);
+      AES256_SetPerms(pEncryptDict, m_Permissions,
+                      pEncryptDict->GetBooleanFor("EncryptMetadata", true),
+                      m_EncryptKey);
+    }
+    return;
+  }
+  if (bDefault) {
+    uint8_t passcode[32];
+    for (uint32_t i = 0; i < 32; i++) {
+      passcode[i] =
+          i < owner_size ? owner_pass[i] : defpasscode[i - owner_size];
+    }
+    uint8_t digest[16];
+    CRYPT_MD5Generate(passcode, 32, digest);
+    if (m_Revision >= 3) {
+      for (uint32_t i = 0; i < 50; i++)
+        CRYPT_MD5Generate(digest, 16, digest);
+    }
+    uint8_t enckey[32];
+    FXSYS_memcpy(enckey, digest, key_len);
+    for (uint32_t i = 0; i < 32; i++) {
+      passcode[i] = i < user_size ? user_pass[i] : defpasscode[i - user_size];
+    }
+    CRYPT_ArcFourCryptBlock(passcode, 32, enckey, key_len);
+    uint8_t tempkey[32];
+    if (m_Revision >= 3) {
+      for (uint8_t i = 1; i <= 19; i++) {
+        for (int j = 0; j < key_len; j++)
+          tempkey[j] = enckey[j] ^ i;
+        CRYPT_ArcFourCryptBlock(passcode, 32, tempkey, key_len);
+      }
+    }
+    pEncryptDict->SetStringFor("O", CFX_ByteString(passcode, 32));
+  }
+  CalcEncryptKey(m_pEncryptDict, (uint8_t*)user_pass, user_size, m_EncryptKey,
+                 key_len, FALSE, pIdArray);
+  if (m_Revision < 3) {
+    uint8_t tempbuf[32];
+    FXSYS_memcpy(tempbuf, defpasscode, 32);
+    CRYPT_ArcFourCryptBlock(tempbuf, 32, m_EncryptKey, key_len);
+    pEncryptDict->SetStringFor("U", CFX_ByteString(tempbuf, 32));
+  } else {
+    uint8_t md5[100];
+    CRYPT_MD5Start(md5);
+    CRYPT_MD5Update(md5, defpasscode, 32);
+    if (pIdArray) {
+      CFX_ByteString id = pIdArray->GetStringAt(0);
+      CRYPT_MD5Update(md5, (uint8_t*)id.c_str(), id.GetLength());
+    }
+    uint8_t digest[32];
+    CRYPT_MD5Finish(md5, digest);
+    CRYPT_ArcFourCryptBlock(digest, 16, m_EncryptKey, key_len);
+    uint8_t tempkey[32];
+    for (uint8_t i = 1; i <= 19; i++) {
+      for (int j = 0; j < key_len; j++) {
+        tempkey[j] = m_EncryptKey[j] ^ i;
+      }
+      CRYPT_ArcFourCryptBlock(digest, 16, tempkey, key_len);
+    }
+    CRYPT_MD5Generate(digest, 16, digest + 16);
+    pEncryptDict->SetStringFor("U", CFX_ByteString(digest, 32));
+  }
+}
+void CPDF_SecurityHandler::OnCreate(CPDF_Dictionary* pEncryptDict,
+                                    CPDF_Array* pIdArray,
+                                    const uint8_t* user_pass,
+                                    uint32_t user_size,
+                                    const uint8_t* owner_pass,
+                                    uint32_t owner_size,
+                                    uint32_t type) {
+  OnCreate(pEncryptDict, pIdArray, user_pass, user_size, owner_pass, owner_size,
+           TRUE, type);
+}
+void CPDF_SecurityHandler::OnCreate(CPDF_Dictionary* pEncryptDict,
+                                    CPDF_Array* pIdArray,
+                                    const uint8_t* user_pass,
+                                    uint32_t user_size,
+                                    uint32_t type) {
+  OnCreate(pEncryptDict, pIdArray, user_pass, user_size, nullptr, 0, FALSE,
+           type);
+}
+void CPDF_SecurityHandler::AES256_SetPassword(CPDF_Dictionary* pEncryptDict,
+                                              const uint8_t* password,
+                                              uint32_t size,
+                                              FX_BOOL bOwner,
+                                              const uint8_t* key) {
+  uint8_t sha[128];
+  CRYPT_SHA1Start(sha);
+  CRYPT_SHA1Update(sha, key, 32);
+  CRYPT_SHA1Update(sha, (uint8_t*)"hello", 5);
+  uint8_t digest[20];
+  CRYPT_SHA1Finish(sha, digest);
+  CFX_ByteString ukey = pEncryptDict->GetStringFor("U");
+  uint8_t digest1[48];
+  if (m_Revision >= 6) {
+    Revision6_Hash(password, size, digest, bOwner ? ukey.raw_str() : nullptr,
+                   digest1);
+  } else {
+    CRYPT_SHA256Start(sha);
+    CRYPT_SHA256Update(sha, password, size);
+    CRYPT_SHA256Update(sha, digest, 8);
+    if (bOwner) {
+      CRYPT_SHA256Update(sha, ukey.raw_str(), ukey.GetLength());
+    }
+    CRYPT_SHA256Finish(sha, digest1);
+  }
+  FXSYS_memcpy(digest1 + 32, digest, 16);
+  pEncryptDict->SetStringFor(bOwner ? "O" : "U", CFX_ByteString(digest1, 48));
+  if (m_Revision >= 6) {
+    Revision6_Hash(password, size, digest + 8,
+                   bOwner ? ukey.raw_str() : nullptr, digest1);
+  } else {
+    CRYPT_SHA256Start(sha);
+    CRYPT_SHA256Update(sha, password, size);
+    CRYPT_SHA256Update(sha, digest + 8, 8);
+    if (bOwner) {
+      CRYPT_SHA256Update(sha, ukey.raw_str(), ukey.GetLength());
+    }
+    CRYPT_SHA256Finish(sha, digest1);
+  }
+  uint8_t* aes = FX_Alloc(uint8_t, 2048);
+  CRYPT_AESSetKey(aes, 16, digest1, 32, TRUE);
+  uint8_t iv[16];
+  FXSYS_memset(iv, 0, 16);
+  CRYPT_AESSetIV(aes, iv);
+  CRYPT_AESEncrypt(aes, digest1, key, 32);
+  FX_Free(aes);
+  pEncryptDict->SetStringFor(bOwner ? "OE" : "UE", CFX_ByteString(digest1, 32));
+}
+void CPDF_SecurityHandler::AES256_SetPerms(CPDF_Dictionary* pEncryptDict,
+                                           uint32_t permissions,
+                                           FX_BOOL bEncryptMetadata,
+                                           const uint8_t* key) {
+  uint8_t buf[16];
+  buf[0] = (uint8_t)permissions;
+  buf[1] = (uint8_t)(permissions >> 8);
+  buf[2] = (uint8_t)(permissions >> 16);
+  buf[3] = (uint8_t)(permissions >> 24);
+  buf[4] = 0xff;
+  buf[5] = 0xff;
+  buf[6] = 0xff;
+  buf[7] = 0xff;
+  buf[8] = bEncryptMetadata ? 'T' : 'F';
+  buf[9] = 'a';
+  buf[10] = 'd';
+  buf[11] = 'b';
+  uint8_t* aes = FX_Alloc(uint8_t, 2048);
+  CRYPT_AESSetKey(aes, 16, key, 32, TRUE);
+  uint8_t iv[16], buf1[16];
+  FXSYS_memset(iv, 0, 16);
+  CRYPT_AESSetIV(aes, iv);
+  CRYPT_AESEncrypt(aes, buf1, buf, 16);
+  FX_Free(aes);
+  pEncryptDict->SetStringFor("Perms", CFX_ByteString(buf1, 16));
+}
diff --git a/core/fpdfapi/parser/cpdf_security_handler.h b/core/fpdfapi/parser/cpdf_security_handler.h
new file mode 100644
index 0000000000..686a25c1c5
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_security_handler.h
@@ -0,0 +1,110 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#ifndef CORE_FPDFAPI_PARSER_CPDF_SECURITY_HANDLER_H_
+#define CORE_FPDFAPI_PARSER_CPDF_SECURITY_HANDLER_H_
+
+#include "core/fxcrt/fx_string.h"
+#include "core/fxcrt/fx_system.h"
+
+#define FXCIPHER_NONE 0
+#define FXCIPHER_RC4 1
+#define FXCIPHER_AES 2
+#define FXCIPHER_AES2 3
+
+#define PDF_ENCRYPT_CONTENT 0
+
+class CPDF_Array;
+class CPDF_CryptoHandler;
+class CPDF_Dictionary;
+class CPDF_Parser;
+
+class CPDF_SecurityHandler {
+ public:
+  CPDF_SecurityHandler();
+  ~CPDF_SecurityHandler();
+
+  FX_BOOL OnInit(CPDF_Parser* pParser, CPDF_Dictionary* pEncryptDict);
+  uint32_t GetPermissions();
+  FX_BOOL GetCryptInfo(int& cipher, const uint8_t*& buffer, int& keylen);
+  bool IsMetadataEncrypted() const;
+  CPDF_CryptoHandler* CreateCryptoHandler();
+
+  void OnCreate(CPDF_Dictionary* pEncryptDict,
+                CPDF_Array* pIdArray,
+                const uint8_t* user_pass,
+                uint32_t user_size,
+                const uint8_t* owner_pass,
+                uint32_t owner_size,
+                uint32_t type = PDF_ENCRYPT_CONTENT);
+
+  void OnCreate(CPDF_Dictionary* pEncryptDict,
+                CPDF_Array* pIdArray,
+                const uint8_t* user_pass,
+                uint32_t user_size,
+                uint32_t type = PDF_ENCRYPT_CONTENT);
+
+  CFX_ByteString GetUserPassword(const uint8_t* owner_pass,
+                                 uint32_t pass_size,
+                                 int32_t key_len);
+  int CheckPassword(const uint8_t* password,
+                    uint32_t pass_size,
+                    FX_BOOL bOwner,
+                    uint8_t* key,
+                    int key_len);
+
+ private:
+  FX_BOOL LoadDict(CPDF_Dictionary* pEncryptDict);
+  FX_BOOL LoadDict(CPDF_Dictionary* pEncryptDict,
+                   uint32_t type,
+                   int& cipher,
+                   int& key_len);
+
+  FX_BOOL CheckUserPassword(const uint8_t* password,
+                            uint32_t pass_size,
+                            FX_BOOL bIgnoreEncryptMeta,
+                            uint8_t* key,
+                            int32_t key_len);
+
+  FX_BOOL CheckOwnerPassword(const uint8_t* password,
+                             uint32_t pass_size,
+                             uint8_t* key,
+                             int32_t key_len);
+  FX_BOOL AES256_CheckPassword(const uint8_t* password,
+                               uint32_t size,
+                               FX_BOOL bOwner,
+                               uint8_t* key);
+  void AES256_SetPassword(CPDF_Dictionary* pEncryptDict,
+                          const uint8_t* password,
+                          uint32_t size,
+                          FX_BOOL bOwner,
+                          const uint8_t* key);
+  void AES256_SetPerms(CPDF_Dictionary* pEncryptDict,
+                       uint32_t permission,
+                       FX_BOOL bEncryptMetadata,
+                       const uint8_t* key);
+  void OnCreate(CPDF_Dictionary* pEncryptDict,
+                CPDF_Array* pIdArray,
+                const uint8_t* user_pass,
+                uint32_t user_size,
+                const uint8_t* owner_pass,
+                uint32_t owner_size,
+                FX_BOOL bDefault,
+                uint32_t type);
+  FX_BOOL CheckSecurity(int32_t key_len);
+
+  int m_Version;
+  int m_Revision;
+  CPDF_Parser* m_pParser;
+  CPDF_Dictionary* m_pEncryptDict;
+  uint32_t m_Permissions;
+  int m_Cipher;
+  uint8_t m_EncryptKey[32];
+  int m_KeyLen;
+  bool m_bOwnerUnlocked;
+};
+
+#endif  // CORE_FPDFAPI_PARSER_CPDF_SECURITY_HANDLER_H_
diff --git a/core/fpdfapi/parser/cpdf_security_handler_embeddertest.cpp b/core/fpdfapi/parser/cpdf_security_handler_embeddertest.cpp
new file mode 100644
index 0000000000..37b6d8fc33
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_security_handler_embeddertest.cpp
@@ -0,0 +1,32 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "testing/embedder_test.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+class CPDFSecurityHandlerEmbeddertest : public EmbedderTest {};
+
+TEST_F(CPDFSecurityHandlerEmbeddertest, Unencrypted) {
+  ASSERT_TRUE(OpenDocument("about_blank.pdf"));
+  EXPECT_EQ(0xFFFFFFFF, FPDF_GetDocPermissions(document()));
+}
+
+TEST_F(CPDFSecurityHandlerEmbeddertest, UnencryptedWithPassword) {
+  ASSERT_TRUE(OpenDocument("about_blank.pdf", "foobar"));
+  EXPECT_EQ(0xFFFFFFFF, FPDF_GetDocPermissions(document()));
+}
+
+TEST_F(CPDFSecurityHandlerEmbeddertest, NoPassword) {
+  EXPECT_FALSE(OpenDocument("encrypted.pdf"));
+}
+
+TEST_F(CPDFSecurityHandlerEmbeddertest, UserPassword) {
+  ASSERT_TRUE(OpenDocument("encrypted.pdf", "1234"));
+  EXPECT_EQ(0xFFFFF2C0, FPDF_GetDocPermissions(document()));
+}
+
+TEST_F(CPDFSecurityHandlerEmbeddertest, OwnerPassword) {
+  ASSERT_TRUE(OpenDocument("encrypted.pdf", "5678"));
+  EXPECT_EQ(0xFFFFFFFC, FPDF_GetDocPermissions(document()));
+}
diff --git a/core/fpdfapi/parser/cpdf_simple_parser.cpp b/core/fpdfapi/parser/cpdf_simple_parser.cpp
new file mode 100644
index 0000000000..650c216e05
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_simple_parser.cpp
@@ -0,0 +1,170 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#include "core/fpdfapi/parser/cpdf_simple_parser.h"
+
+#include "core/fpdfapi/parser/fpdf_parser_utility.h"
+
+CPDF_SimpleParser::CPDF_SimpleParser(const uint8_t* pData, uint32_t dwSize)
+    : m_pData(pData), m_dwSize(dwSize), m_dwCurPos(0) {}
+
+CPDF_SimpleParser::CPDF_SimpleParser(const CFX_ByteStringC& str)
+    : m_pData(str.raw_str()), m_dwSize(str.GetLength()), m_dwCurPos(0) {}
+
+void CPDF_SimpleParser::ParseWord(const uint8_t*& pStart, uint32_t& dwSize) {
+  pStart = nullptr;
+  dwSize = 0;
+  uint8_t ch;
+  while (1) {
+    if (m_dwSize <= m_dwCurPos)
+      return;
+    ch = m_pData[m_dwCurPos++];
+    while (PDFCharIsWhitespace(ch)) {
+      if (m_dwSize <= m_dwCurPos)
+        return;
+      ch = m_pData[m_dwCurPos++];
+    }
+
+    if (ch != '%')
+      break;
+
+    while (1) {
+      if (m_dwSize <= m_dwCurPos)
+        return;
+      ch = m_pData[m_dwCurPos++];
+      if (PDFCharIsLineEnding(ch))
+        break;
+    }
+  }
+
+  uint32_t start_pos = m_dwCurPos - 1;
+  pStart = m_pData + start_pos;
+  if (PDFCharIsDelimiter(ch)) {
+    if (ch == '/') {
+      while (1) {
+        if (m_dwSize <= m_dwCurPos)
+          return;
+        ch = m_pData[m_dwCurPos++];
+        if (!PDFCharIsOther(ch) && !PDFCharIsNumeric(ch)) {
+          m_dwCurPos--;
+          dwSize = m_dwCurPos - start_pos;
+          return;
+        }
+      }
+    } else {
+      dwSize = 1;
+      if (ch == '<') {
+        if (m_dwSize <= m_dwCurPos)
+          return;
+        ch = m_pData[m_dwCurPos++];
+        if (ch == '<')
+          dwSize = 2;
+        else
+          m_dwCurPos--;
+      } else if (ch == '>') {
+        if (m_dwSize <= m_dwCurPos)
+          return;
+        ch = m_pData[m_dwCurPos++];
+        if (ch == '>')
+          dwSize = 2;
+        else
+          m_dwCurPos--;
+      }
+    }
+    return;
+  }
+
+  dwSize = 1;
+  while (1) {
+    if (m_dwSize <= m_dwCurPos)
+      return;
+    ch = m_pData[m_dwCurPos++];
+
+    if (PDFCharIsDelimiter(ch) || PDFCharIsWhitespace(ch)) {
+      m_dwCurPos--;
+      break;
+    }
+    dwSize++;
+  }
+}
+
+CFX_ByteStringC CPDF_SimpleParser::GetWord() {
+  const uint8_t* pStart;
+  uint32_t dwSize;
+  ParseWord(pStart, dwSize);
+  if (dwSize == 1 && pStart[0] == '<') {
+    while (m_dwCurPos < m_dwSize && m_pData[m_dwCurPos] != '>') {
+      m_dwCurPos++;
+    }
+    if (m_dwCurPos < m_dwSize) {
+      m_dwCurPos++;
+    }
+    return CFX_ByteStringC(pStart,
+                           (FX_STRSIZE)(m_dwCurPos - (pStart - m_pData)));
+  }
+  if (dwSize == 1 && pStart[0] == '(') {
+    int level = 1;
+    while (m_dwCurPos < m_dwSize) {
+      if (m_pData[m_dwCurPos] == ')') {
+        level--;
+        if (level == 0) {
+          break;
+        }
+      }
+      if (m_pData[m_dwCurPos] == '\\') {
+        if (m_dwSize <= m_dwCurPos) {
+          break;
+        }
+        m_dwCurPos++;
+      } else if (m_pData[m_dwCurPos] == '(') {
+        level++;
+      }
+      if (m_dwSize <= m_dwCurPos) {
+        break;
+      }
+      m_dwCurPos++;
+    }
+    if (m_dwCurPos < m_dwSize) {
+      m_dwCurPos++;
+    }
+    return CFX_ByteStringC(pStart,
+                           (FX_STRSIZE)(m_dwCurPos - (pStart - m_pData)));
+  }
+  return CFX_ByteStringC(pStart, dwSize);
+}
+
+bool CPDF_SimpleParser::FindTagParamFromStart(const CFX_ByteStringC& token,
+                                              int nParams) {
+  nParams++;
+  uint32_t* pBuf = FX_Alloc(uint32_t, nParams);
+  int buf_index = 0;
+  int buf_count = 0;
+  m_dwCurPos = 0;
+  while (1) {
+    pBuf[buf_index++] = m_dwCurPos;
+    if (buf_index == nParams) {
+      buf_index = 0;
+    }
+    buf_count++;
+    if (buf_count > nParams) {
+      buf_count = nParams;
+    }
+    CFX_ByteStringC word = GetWord();
+    if (word.IsEmpty()) {
+      FX_Free(pBuf);
+      return false;
+    }
+    if (word == token) {
+      if (buf_count < nParams) {
+        continue;
+      }
+      m_dwCurPos = pBuf[buf_index];
+      FX_Free(pBuf);
+      return true;
+    }
+  }
+  return false;
+}
diff --git a/core/fpdfapi/parser/cpdf_simple_parser.h b/core/fpdfapi/parser/cpdf_simple_parser.h
new file mode 100644
index 0000000000..c638b8a04b
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_simple_parser.h
@@ -0,0 +1,35 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#ifndef CORE_FPDFAPI_PARSER_CPDF_SIMPLE_PARSER_H_
+#define CORE_FPDFAPI_PARSER_CPDF_SIMPLE_PARSER_H_
+
+#include "core/fxcrt/fx_string.h"
+#include "core/fxcrt/fx_system.h"
+
+class CPDF_SimpleParser {
+ public:
+  CPDF_SimpleParser(const uint8_t* pData, uint32_t dwSize);
+  CPDF_SimpleParser(const CFX_ByteStringC& str);
+
+  CFX_ByteStringC GetWord();
+
+  // Find the token and its |nParams| parameters from the start of data,
+  // and move the current position to the start of those parameters.
+  bool FindTagParamFromStart(const CFX_ByteStringC& token, int nParams);
+
+  // For testing only.
+  uint32_t GetCurPos() const { return m_dwCurPos; }
+
+ private:
+  void ParseWord(const uint8_t*& pStart, uint32_t& dwSize);
+
+  const uint8_t* m_pData;
+  uint32_t m_dwSize;
+  uint32_t m_dwCurPos;
+};
+
+#endif  // CORE_FPDFAPI_PARSER_CPDF_SIMPLE_PARSER_H_
diff --git a/core/fpdfapi/parser/cpdf_simple_parser_unittest.cpp b/core/fpdfapi/parser/cpdf_simple_parser_unittest.cpp
new file mode 100644
index 0000000000..5f56b948cd
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_simple_parser_unittest.cpp
@@ -0,0 +1,96 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "core/fpdfapi/parser/cpdf_simple_parser.h"
+
+#include <string>
+
+#include "core/fpdfapi/parser/fpdf_parser_utility.h"
+#include "core/fxcrt/fx_basic.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "testing/test_support.h"
+
+TEST(SimpleParserTest, GetWord) {
+  pdfium::StrFuncTestData test_data[] = {
+      // Empty src string.
+      STR_IN_OUT_CASE("", ""),
+      // Content with whitespaces only.
+      STR_IN_OUT_CASE(" \t \0 \n", ""),
+      // Content with comments only.
+      STR_IN_OUT_CASE("%this is a test case\r\n%2nd line", ""),
+      // Mixed whitespaces and comments.
+      STR_IN_OUT_CASE(" \t \0%try()%haha\n %another line \aa", ""),
+      // Name.
+      STR_IN_OUT_CASE(" /Tester ", "/Tester"),
+      // String.
+      STR_IN_OUT_CASE("\t(nice day)!\n ", "(nice day)"),
+      // String with nested braces.
+      STR_IN_OUT_CASE("\t(It is a (long) day)!\n ", "(It is a (long) day)"),
+      // String with escaped chars.
+      STR_IN_OUT_CASE("\t(It is a \\(long\\) day!)hi\n ",
+                      "(It is a \\(long\\) day!)"),
+      // Hex string.
+      STR_IN_OUT_CASE(" \n<4545acdfedertt>abc ", "<4545acdfedertt>"),
+      STR_IN_OUT_CASE(" \n<4545a<ed>ertt>abc ", "<4545a<ed>"),
+      // Dictionary.
+      STR_IN_OUT_CASE("<</oc 234 /color 2 3 R>>", "<<"),
+      STR_IN_OUT_CASE("\t\t<< /abc>>", "<<"),
+      // Handling ending delimiters.
+      STR_IN_OUT_CASE("> little bear", ">"),
+      STR_IN_OUT_CASE(") another bear", ")"), STR_IN_OUT_CASE(">> end ", ">>"),
+      // No ending delimiters.
+      STR_IN_OUT_CASE("(sdfgfgbcv", "(sdfgfgbcv"),
+      // Regular cases.
+      STR_IN_OUT_CASE("apple pear", "apple"),
+      STR_IN_OUT_CASE(" pi=3.1415 ", "pi=3.1415"),
+      STR_IN_OUT_CASE(" p t x c ", "p"), STR_IN_OUT_CASE(" pt\0xc ", "pt"),
+      STR_IN_OUT_CASE(" $^&&*\t\0sdff ", "$^&&*"),
+      STR_IN_OUT_CASE("\n\r+3.5656 -11.0", "+3.5656"),
+  };
+  for (size_t i = 0; i < FX_ArraySize(test_data); ++i) {
+    const pdfium::StrFuncTestData& data = test_data[i];
+    CPDF_SimpleParser parser(data.input, data.input_size);
+    CFX_ByteStringC word = parser.GetWord();
+    EXPECT_EQ(std::string(reinterpret_cast<const char*>(data.expected),
+                          data.expected_size),
+              std::string(word.c_str(), word.GetLength()))
+        << " for case " << i;
+  }
+}
+
+TEST(SimpleParserTest, FindTagParamFromStart) {
+  struct FindTagTestStruct {
+    const unsigned char* input;
+    unsigned int input_size;
+    const char* token;
+    int num_params;
+    bool result;
+    unsigned int result_pos;
+  } test_data[] = {
+      // Empty strings.
+      STR_IN_TEST_CASE("", "Tj", 1, false, 0),
+      STR_IN_TEST_CASE("", "", 1, false, 0),
+      // Empty token.
+      STR_IN_TEST_CASE("  T j", "", 1, false, 5),
+      // No parameter.
+      STR_IN_TEST_CASE("Tj", "Tj", 1, false, 2),
+      STR_IN_TEST_CASE("(Tj", "Tj", 1, false, 3),
+      // Partial token match.
+      STR_IN_TEST_CASE("\r12\t34  56 78Tj", "Tj", 1, false, 15),
+      // Regular cases with various parameters.
+      STR_IN_TEST_CASE("\r\0abd Tj", "Tj", 1, true, 0),
+      STR_IN_TEST_CASE("12 4 Tj 3 46 Tj", "Tj", 1, true, 2),
+      STR_IN_TEST_CASE("er^ 2 (34) (5667) Tj", "Tj", 2, true, 5),
+      STR_IN_TEST_CASE("<344> (232)\t343.4\n12 45 Tj", "Tj", 3, true, 11),
+      STR_IN_TEST_CASE("1 2 3 4 5 6 7 8 cm", "cm", 6, true, 3),
+  };
+  for (size_t i = 0; i < FX_ArraySize(test_data); ++i) {
+    const FindTagTestStruct& data = test_data[i];
+    CPDF_SimpleParser parser(data.input, data.input_size);
+    EXPECT_EQ(data.result,
+              parser.FindTagParamFromStart(data.token, data.num_params))
+        << " for case " << i;
+    EXPECT_EQ(data.result_pos, parser.GetCurPos()) << " for case " << i;
+  }
+}
diff --git a/core/fpdfapi/parser/cpdf_stream.cpp b/core/fpdfapi/parser/cpdf_stream.cpp
new file mode 100644
index 0000000000..c221edec68
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_stream.cpp
@@ -0,0 +1,116 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#include "core/fpdfapi/parser/cpdf_stream.h"
+
+#include "core/fpdfapi/parser/cpdf_dictionary.h"
+#include "core/fpdfapi/parser/cpdf_stream_acc.h"
+#include "core/fpdfapi/parser/fpdf_parser_decode.h"
+#include "third_party/base/numerics/safe_conversions.h"
+#include "third_party/base/stl_util.h"
+
+CPDF_Stream::CPDF_Stream() {}
+
+CPDF_Stream::CPDF_Stream(uint8_t* pData, uint32_t size, CPDF_Dictionary* pDict)
+    : m_pDict(pDict), m_dwSize(size), m_pDataBuf(pData) {}
+
+CPDF_Stream::~CPDF_Stream() {}
+
+CPDF_Object::Type CPDF_Stream::GetType() const {
+  return STREAM;
+}
+
+CPDF_Dictionary* CPDF_Stream::GetDict() const {
+  return m_pDict.get();
+}
+
+bool CPDF_Stream::IsStream() const {
+  return true;
+}
+
+CPDF_Stream* CPDF_Stream::AsStream() {
+  return this;
+}
+
+const CPDF_Stream* CPDF_Stream::AsStream() const {
+  return this;
+}
+
+void CPDF_Stream::InitStream(const uint8_t* pData,
+                             uint32_t size,
+                             CPDF_Dictionary* pDict) {
+  m_pDict.reset(pDict);
+  m_bMemoryBased = true;
+  m_pFile = nullptr;
+  m_pDataBuf.reset(FX_Alloc(uint8_t, size));
+  if (pData)
+    FXSYS_memcpy(m_pDataBuf.get(), pData, size);
+  m_dwSize = size;
+  if (m_pDict)
+    m_pDict->SetIntegerFor("Length", m_dwSize);
+}
+
+void CPDF_Stream::InitStreamFromFile(IFX_FileRead* pFile,
+                                     CPDF_Dictionary* pDict) {
+  m_pDict.reset(pDict);
+  m_bMemoryBased = false;
+  m_pDataBuf.reset();
+  m_pFile = pFile;
+  m_dwSize = pdfium::base::checked_cast<uint32_t>(pFile->GetSize());
+  if (m_pDict)
+    m_pDict->SetIntegerFor("Length", m_dwSize);
+}
+
+CPDF_Object* CPDF_Stream::Clone() const {
+  return CloneObjectNonCyclic(false);
+}
+
+CPDF_Object* CPDF_Stream::CloneNonCyclic(
+    bool bDirect,
+    std::set<const CPDF_Object*>* pVisited) const {
+  pVisited->insert(this);
+  CPDF_StreamAcc acc;
+  acc.LoadAllData(this, TRUE);
+  uint32_t streamSize = acc.GetSize();
+  CPDF_Dictionary* pDict = GetDict();
+  if (pDict && !pdfium::ContainsKey(*pVisited, pDict)) {
+    pDict = ToDictionary(
+        static_cast<CPDF_Object*>(pDict)->CloneNonCyclic(bDirect, pVisited));
+  }
+
+  return new CPDF_Stream(acc.DetachData(), streamSize, pDict);
+}
+
+void CPDF_Stream::SetData(const uint8_t* pData, uint32_t size) {
+  m_bMemoryBased = true;
+  m_pDataBuf.reset(FX_Alloc(uint8_t, size));
+  if (pData)
+    FXSYS_memcpy(m_pDataBuf.get(), pData, size);
+  m_dwSize = size;
+  if (!m_pDict)
+    m_pDict.reset(new CPDF_Dictionary());
+  m_pDict->SetIntegerFor("Length", size);
+  m_pDict->RemoveFor("Filter");
+  m_pDict->RemoveFor("DecodeParms");
+}
+
+FX_BOOL CPDF_Stream::ReadRawData(FX_FILESIZE offset,
+                                 uint8_t* buf,
+                                 uint32_t size) const {
+  if (m_bMemoryBased && m_pFile)
+    return m_pFile->ReadBlock(buf, offset, size);
+
+  if (m_pDataBuf)
+    FXSYS_memcpy(buf, m_pDataBuf.get() + offset, size);
+
+  return TRUE;
+}
+
+CFX_WideString CPDF_Stream::GetUnicodeText() const {
+  CPDF_StreamAcc stream;
+  stream.LoadAllData(this, FALSE);
+  return PDF_DecodeText(stream.GetData(), stream.GetSize());
+}
diff --git a/core/fpdfapi/parser/cpdf_stream.h b/core/fpdfapi/parser/cpdf_stream.h
new file mode 100644
index 0000000000..6a4f1011c0
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_stream.h
@@ -0,0 +1,61 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#ifndef CORE_FPDFAPI_PARSER_CPDF_STREAM_H_
+#define CORE_FPDFAPI_PARSER_CPDF_STREAM_H_
+
+#include <memory>
+#include <set>
+
+#include "core/fpdfapi/parser/cpdf_dictionary.h"
+#include "core/fpdfapi/parser/cpdf_object.h"
+#include "core/fxcrt/fx_basic.h"
+
+class CPDF_Stream : public CPDF_Object {
+ public:
+  CPDF_Stream();
+
+  // Takes ownership of |pData| and |pDict|.
+  CPDF_Stream(uint8_t* pData, uint32_t size, CPDF_Dictionary* pDict);
+
+  // CPDF_Object.
+  Type GetType() const override;
+  CPDF_Object* Clone() const override;
+  CPDF_Dictionary* GetDict() const override;
+  CFX_WideString GetUnicodeText() const override;
+  bool IsStream() const override;
+  CPDF_Stream* AsStream() override;
+  const CPDF_Stream* AsStream() const override;
+
+  uint32_t GetRawSize() const { return m_dwSize; }
+  uint8_t* GetRawData() const { return m_pDataBuf.get(); }
+
+  // Does not takes onwership of |pData|, copies into internally-owned buffer.
+  void SetData(const uint8_t* pData, uint32_t size);
+
+  void InitStream(const uint8_t* pData, uint32_t size, CPDF_Dictionary* pDict);
+  void InitStreamFromFile(IFX_FileRead* pFile, CPDF_Dictionary* pDict);
+
+  FX_BOOL ReadRawData(FX_FILESIZE start_pos,
+                      uint8_t* pBuf,
+                      uint32_t buf_size) const;
+
+  bool IsMemoryBased() const { return m_bMemoryBased; }
+
+ protected:
+  ~CPDF_Stream() override;
+  CPDF_Object* CloneNonCyclic(
+      bool bDirect,
+      std::set<const CPDF_Object*>* pVisited) const override;
+
+  std::unique_ptr<CPDF_Dictionary, ReleaseDeleter<CPDF_Dictionary>> m_pDict;
+  bool m_bMemoryBased = true;
+  uint32_t m_dwSize = 0;
+  std::unique_ptr<uint8_t, FxFreeDeleter> m_pDataBuf;
+  IFX_FileRead* m_pFile = nullptr;
+};
+
+#endif  // CORE_FPDFAPI_PARSER_CPDF_STREAM_H_
diff --git a/core/fpdfapi/parser/cpdf_stream_acc.cpp b/core/fpdfapi/parser/cpdf_stream_acc.cpp
new file mode 100644
index 0000000000..e8bf6d7e15
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_stream_acc.cpp
@@ -0,0 +1,91 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#include "core/fpdfapi/parser/cpdf_stream_acc.h"
+
+#include "core/fpdfapi/parser/fpdf_parser_decode.h"
+
+CPDF_StreamAcc::CPDF_StreamAcc()
+    : m_pData(nullptr),
+      m_dwSize(0),
+      m_bNewBuf(FALSE),
+      m_pImageParam(nullptr),
+      m_pStream(nullptr),
+      m_pSrcData(nullptr) {}
+
+void CPDF_StreamAcc::LoadAllData(const CPDF_Stream* pStream,
+                                 FX_BOOL bRawAccess,
+                                 uint32_t estimated_size,
+                                 FX_BOOL bImageAcc) {
+  if (!pStream)
+    return;
+
+  m_pStream = pStream;
+  if (pStream->IsMemoryBased() &&
+      (!pStream->GetDict()->KeyExist("Filter") || bRawAccess)) {
+    m_dwSize = pStream->GetRawSize();
+    m_pData = pStream->GetRawData();
+    return;
+  }
+  uint8_t* pSrcData;
+  uint32_t dwSrcSize = pStream->GetRawSize();
+  if (dwSrcSize == 0)
+    return;
+
+  if (!pStream->IsMemoryBased()) {
+    pSrcData = m_pSrcData = FX_Alloc(uint8_t, dwSrcSize);
+    if (!pStream->ReadRawData(0, pSrcData, dwSrcSize))
+      return;
+  } else {
+    pSrcData = pStream->GetRawData();
+  }
+  if (!pStream->GetDict()->KeyExist("Filter") || bRawAccess) {
+    m_pData = pSrcData;
+    m_dwSize = dwSrcSize;
+  } else {
+    FX_BOOL bRet = PDF_DataDecode(pSrcData, dwSrcSize, m_pStream->GetDict(),
+                                  m_pData, m_dwSize, m_ImageDecoder,
+                                  m_pImageParam, estimated_size, bImageAcc);
+    if (!bRet) {
+      m_pData = pSrcData;
+      m_dwSize = dwSrcSize;
+    }
+  }
+  if (pSrcData != pStream->GetRawData() && pSrcData != m_pData)
+    FX_Free(pSrcData);
+  m_pSrcData = nullptr;
+  m_bNewBuf = m_pData != pStream->GetRawData();
+}
+
+CPDF_StreamAcc::~CPDF_StreamAcc() {
+  if (m_bNewBuf)
+    FX_Free(m_pData);
+  FX_Free(m_pSrcData);
+}
+
+const uint8_t* CPDF_StreamAcc::GetData() const {
+  if (m_bNewBuf)
+    return m_pData;
+  return m_pStream ? m_pStream->GetRawData() : nullptr;
+}
+
+uint32_t CPDF_StreamAcc::GetSize() const {
+  if (m_bNewBuf)
+    return m_dwSize;
+  return m_pStream ? m_pStream->GetRawSize() : 0;
+}
+
+uint8_t* CPDF_StreamAcc::DetachData() {
+  if (m_bNewBuf) {
+    uint8_t* p = m_pData;
+    m_pData = nullptr;
+    m_dwSize = 0;
+    return p;
+  }
+  uint8_t* p = FX_Alloc(uint8_t, m_dwSize);
+  FXSYS_memcpy(p, m_pData, m_dwSize);
+  return p;
+}
diff --git a/core/fpdfapi/parser/cpdf_stream_acc.h b/core/fpdfapi/parser/cpdf_stream_acc.h
new file mode 100644
index 0000000000..c4f312a113
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_stream_acc.h
@@ -0,0 +1,46 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#ifndef CORE_FPDFAPI_PARSER_CPDF_STREAM_ACC_H_
+#define CORE_FPDFAPI_PARSER_CPDF_STREAM_ACC_H_
+
+#include "core/fpdfapi/parser/cpdf_dictionary.h"
+#include "core/fpdfapi/parser/cpdf_stream.h"
+#include "core/fxcrt/fx_string.h"
+#include "core/fxcrt/fx_system.h"
+
+class CPDF_StreamAcc {
+ public:
+  CPDF_StreamAcc();
+  ~CPDF_StreamAcc();
+
+  void LoadAllData(const CPDF_Stream* pStream,
+                   FX_BOOL bRawAccess = FALSE,
+                   uint32_t estimated_size = 0,
+                   FX_BOOL bImageAcc = FALSE);
+
+  const CPDF_Stream* GetStream() const { return m_pStream; }
+  CPDF_Dictionary* GetDict() const {
+    return m_pStream ? m_pStream->GetDict() : nullptr;
+  }
+
+  const uint8_t* GetData() const;
+  uint32_t GetSize() const;
+  const CFX_ByteString& GetImageDecoder() const { return m_ImageDecoder; }
+  const CPDF_Dictionary* GetImageParam() const { return m_pImageParam; }
+  uint8_t* DetachData();
+
+ protected:
+  uint8_t* m_pData;
+  uint32_t m_dwSize;
+  FX_BOOL m_bNewBuf;
+  CFX_ByteString m_ImageDecoder;
+  CPDF_Dictionary* m_pImageParam;
+  const CPDF_Stream* m_pStream;
+  uint8_t* m_pSrcData;
+};
+
+#endif  // CORE_FPDFAPI_PARSER_CPDF_STREAM_ACC_H_
diff --git a/core/fpdfapi/parser/cpdf_string.cpp b/core/fpdfapi/parser/cpdf_string.cpp
new file mode 100644
index 0000000000..73c7d4cf69
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_string.cpp
@@ -0,0 +1,52 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#include "core/fpdfapi/parser/cpdf_string.h"
+
+#include "core/fpdfapi/parser/fpdf_parser_decode.h"
+
+CPDF_String::CPDF_String() : m_bHex(FALSE) {}
+
+CPDF_String::CPDF_String(const CFX_ByteString& str, FX_BOOL bHex)
+    : m_String(str), m_bHex(bHex) {}
+
+CPDF_String::CPDF_String(const CFX_WideString& str) : m_bHex(FALSE) {
+  m_String = PDF_EncodeText(str);
+}
+
+CPDF_String::~CPDF_String() {}
+
+CPDF_Object::Type CPDF_String::GetType() const {
+  return STRING;
+}
+
+CPDF_Object* CPDF_String::Clone() const {
+  return new CPDF_String(m_String, m_bHex);
+}
+
+CFX_ByteString CPDF_String::GetString() const {
+  return m_String;
+}
+
+void CPDF_String::SetString(const CFX_ByteString& str) {
+  m_String = str;
+}
+
+bool CPDF_String::IsString() const {
+  return true;
+}
+
+CPDF_String* CPDF_String::AsString() {
+  return this;
+}
+
+const CPDF_String* CPDF_String::AsString() const {
+  return this;
+}
+
+CFX_WideString CPDF_String::GetUnicodeText() const {
+  return PDF_DecodeText(m_String);
+}
diff --git a/core/fpdfapi/parser/cpdf_string.h b/core/fpdfapi/parser/cpdf_string.h
new file mode 100644
index 0000000000..d99e00c403
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_string.h
@@ -0,0 +1,39 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#ifndef CORE_FPDFAPI_PARSER_CPDF_STRING_H_
+#define CORE_FPDFAPI_PARSER_CPDF_STRING_H_
+
+#include "core/fpdfapi/parser/cpdf_object.h"
+#include "core/fxcrt/fx_string.h"
+#include "core/fxcrt/fx_system.h"
+
+class CPDF_String : public CPDF_Object {
+ public:
+  CPDF_String();
+  CPDF_String(const CFX_ByteString& str, FX_BOOL bHex);
+  explicit CPDF_String(const CFX_WideString& str);
+
+  // CPDF_Object.
+  Type GetType() const override;
+  CPDF_Object* Clone() const override;
+  CFX_ByteString GetString() const override;
+  CFX_WideString GetUnicodeText() const override;
+  void SetString(const CFX_ByteString& str) override;
+  bool IsString() const override;
+  CPDF_String* AsString() override;
+  const CPDF_String* AsString() const override;
+
+  FX_BOOL IsHex() const { return m_bHex; }
+
+ protected:
+  ~CPDF_String() override;
+
+  CFX_ByteString m_String;
+  FX_BOOL m_bHex;
+};
+
+#endif  // CORE_FPDFAPI_PARSER_CPDF_STRING_H_
diff --git a/core/fpdfapi/parser/cpdf_syntax_parser.cpp b/core/fpdfapi/parser/cpdf_syntax_parser.cpp
new file mode 100644
index 0000000000..e7f25d15c2
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_syntax_parser.cpp
@@ -0,0 +1,997 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#include "core/fpdfapi/parser/cpdf_syntax_parser.h"
+
+#include <vector>
+
+#include "core/fpdfapi/cpdf_modulemgr.h"
+#include "core/fpdfapi/parser/cpdf_array.h"
+#include "core/fpdfapi/parser/cpdf_boolean.h"
+#include "core/fpdfapi/parser/cpdf_crypto_handler.h"
+#include "core/fpdfapi/parser/cpdf_dictionary.h"
+#include "core/fpdfapi/parser/cpdf_name.h"
+#include "core/fpdfapi/parser/cpdf_null.h"
+#include "core/fpdfapi/parser/cpdf_number.h"
+#include "core/fpdfapi/parser/cpdf_reference.h"
+#include "core/fpdfapi/parser/cpdf_stream.h"
+#include "core/fpdfapi/parser/cpdf_string.h"
+#include "core/fpdfapi/parser/fpdf_parser_decode.h"
+#include "core/fpdfapi/parser/fpdf_parser_utility.h"
+#include "core/fxcrt/fx_ext.h"
+#include "third_party/base/numerics/safe_math.h"
+
+namespace {
+
+struct SearchTagRecord {
+  CFX_ByteStringC m_bsTag;
+  FX_STRSIZE m_Offset;
+};
+
+}  // namespace
+
+// static
+int CPDF_SyntaxParser::s_CurrentRecursionDepth = 0;
+
+CPDF_SyntaxParser::CPDF_SyntaxParser()
+    : CPDF_SyntaxParser(CFX_WeakPtr<CFX_ByteStringPool>()) {}
+
+CPDF_SyntaxParser::CPDF_SyntaxParser(
+    const CFX_WeakPtr<CFX_ByteStringPool>& pPool)
+    : m_MetadataObjnum(0),
+      m_pFileAccess(nullptr),
+      m_pFileBuf(nullptr),
+      m_BufSize(CPDF_ModuleMgr::kFileBufSize),
+      m_pPool(pPool) {}
+
+CPDF_SyntaxParser::~CPDF_SyntaxParser() {
+  FX_Free(m_pFileBuf);
+}
+
+FX_BOOL CPDF_SyntaxParser::GetCharAt(FX_FILESIZE pos, uint8_t& ch) {
+  CFX_AutoRestorer<FX_FILESIZE> save_pos(&m_Pos);
+  m_Pos = pos;
+  return GetNextChar(ch);
+}
+
+FX_BOOL CPDF_SyntaxParser::GetNextChar(uint8_t& ch) {
+  FX_FILESIZE pos = m_Pos + m_HeaderOffset;
+  if (pos >= m_FileLen)
+    return FALSE;
+
+  if (m_BufOffset >= pos || (FX_FILESIZE)(m_BufOffset + m_BufSize) <= pos) {
+    FX_FILESIZE read_pos = pos;
+    uint32_t read_size = m_BufSize;
+    if ((FX_FILESIZE)read_size > m_FileLen)
+      read_size = (uint32_t)m_FileLen;
+
+    if ((FX_FILESIZE)(read_pos + read_size) > m_FileLen) {
+      if (m_FileLen < (FX_FILESIZE)read_size) {
+        read_pos = 0;
+        read_size = (uint32_t)m_FileLen;
+      } else {
+        read_pos = m_FileLen - read_size;
+      }
+    }
+
+    if (!m_pFileAccess->ReadBlock(m_pFileBuf, read_pos, read_size))
+      return FALSE;
+
+    m_BufOffset = read_pos;
+  }
+  ch = m_pFileBuf[pos - m_BufOffset];
+  m_Pos++;
+  return TRUE;
+}
+
+FX_BOOL CPDF_SyntaxParser::GetCharAtBackward(FX_FILESIZE pos, uint8_t& ch) {
+  pos += m_HeaderOffset;
+  if (pos >= m_FileLen)
+    return FALSE;
+
+  if (m_BufOffset >= pos || (FX_FILESIZE)(m_BufOffset + m_BufSize) <= pos) {
+    FX_FILESIZE read_pos;
+    if (pos < (FX_FILESIZE)m_BufSize)
+      read_pos = 0;
+    else
+      read_pos = pos - m_BufSize + 1;
+
+    uint32_t read_size = m_BufSize;
+    if ((FX_FILESIZE)(read_pos + read_size) > m_FileLen) {
+      if (m_FileLen < (FX_FILESIZE)read_size) {
+        read_pos = 0;
+        read_size = (uint32_t)m_FileLen;
+      } else {
+        read_pos = m_FileLen - read_size;
+      }
+    }
+
+    if (!m_pFileAccess->ReadBlock(m_pFileBuf, read_pos, read_size))
+      return FALSE;
+
+    m_BufOffset = read_pos;
+  }
+  ch = m_pFileBuf[pos - m_BufOffset];
+  return TRUE;
+}
+
+FX_BOOL CPDF_SyntaxParser::ReadBlock(uint8_t* pBuf, uint32_t size) {
+  if (!m_pFileAccess->ReadBlock(pBuf, m_Pos + m_HeaderOffset, size))
+    return FALSE;
+  m_Pos += size;
+  return TRUE;
+}
+
+void CPDF_SyntaxParser::GetNextWordInternal(bool* bIsNumber) {
+  m_WordSize = 0;
+  if (bIsNumber)
+    *bIsNumber = true;
+
+  uint8_t ch;
+  if (!GetNextChar(ch))
+    return;
+
+  while (1) {
+    while (PDFCharIsWhitespace(ch)) {
+      if (!GetNextChar(ch))
+        return;
+    }
+
+    if (ch != '%')
+      break;
+
+    while (1) {
+      if (!GetNextChar(ch))
+        return;
+      if (PDFCharIsLineEnding(ch))
+        break;
+    }
+  }
+
+  if (PDFCharIsDelimiter(ch)) {
+    if (bIsNumber)
+      *bIsNumber = false;
+
+    m_WordBuffer[m_WordSize++] = ch;
+    if (ch == '/') {
+      while (1) {
+        if (!GetNextChar(ch))
+          return;
+
+        if (!PDFCharIsOther(ch) && !PDFCharIsNumeric(ch)) {
+          m_Pos--;
+          return;
+        }
+
+        if (m_WordSize < sizeof(m_WordBuffer) - 1)
+          m_WordBuffer[m_WordSize++] = ch;
+      }
+    } else if (ch == '<') {
+      if (!GetNextChar(ch))
+        return;
+
+      if (ch == '<')
+        m_WordBuffer[m_WordSize++] = ch;
+      else
+        m_Pos--;
+    } else if (ch == '>') {
+      if (!GetNextChar(ch))
+        return;
+
+      if (ch == '>')
+        m_WordBuffer[m_WordSize++] = ch;
+      else
+        m_Pos--;
+    }
+    return;
+  }
+
+  while (1) {
+    if (m_WordSize < sizeof(m_WordBuffer) - 1)
+      m_WordBuffer[m_WordSize++] = ch;
+
+    if (!PDFCharIsNumeric(ch)) {
+      if (bIsNumber)
+        *bIsNumber = false;
+    }
+
+    if (!GetNextChar(ch))
+      return;
+
+    if (PDFCharIsDelimiter(ch) || PDFCharIsWhitespace(ch)) {
+      m_Pos--;
+      break;
+    }
+  }
+}
+
+CFX_ByteString CPDF_SyntaxParser::ReadString() {
+  uint8_t ch;
+  if (!GetNextChar(ch))
+    return CFX_ByteString();
+
+  CFX_ByteTextBuf buf;
+  int32_t parlevel = 0;
+  int32_t status = 0;
+  int32_t iEscCode = 0;
+  while (1) {
+    switch (status) {
+      case 0:
+        if (ch == ')') {
+          if (parlevel == 0) {
+            return buf.MakeString();
+          }
+          parlevel--;
+          buf.AppendChar(')');
+        } else if (ch == '(') {
+          parlevel++;
+          buf.AppendChar('(');
+        } else if (ch == '\\') {
+          status = 1;
+        } else {
+          buf.AppendChar(ch);
+        }
+        break;
+      case 1:
+        if (ch >= '0' && ch <= '7') {
+          iEscCode = FXSYS_toDecimalDigit(static_cast<FX_WCHAR>(ch));
+          status = 2;
+          break;
+        }
+
+        if (ch == 'n') {
+          buf.AppendChar('\n');
+        } else if (ch == 'r') {
+          buf.AppendChar('\r');
+        } else if (ch == 't') {
+          buf.AppendChar('\t');
+        } else if (ch == 'b') {
+          buf.AppendChar('\b');
+        } else if (ch == 'f') {
+          buf.AppendChar('\f');
+        } else if (ch == '\r') {
+          status = 4;
+          break;
+        } else if (ch != '\n') {
+          buf.AppendChar(ch);
+        }
+        status = 0;
+        break;
+      case 2:
+        if (ch >= '0' && ch <= '7') {
+          iEscCode =
+              iEscCode * 8 + FXSYS_toDecimalDigit(static_cast<FX_WCHAR>(ch));
+          status = 3;
+        } else {
+          buf.AppendChar(iEscCode);
+          status = 0;
+          continue;
+        }
+        break;
+      case 3:
+        if (ch >= '0' && ch <= '7') {
+          iEscCode =
+              iEscCode * 8 + FXSYS_toDecimalDigit(static_cast<FX_WCHAR>(ch));
+          buf.AppendChar(iEscCode);
+          status = 0;
+        } else {
+          buf.AppendChar(iEscCode);
+          status = 0;
+          continue;
+        }
+        break;
+      case 4:
+        status = 0;
+        if (ch != '\n')
+          continue;
+        break;
+    }
+
+    if (!GetNextChar(ch))
+      break;
+  }
+
+  GetNextChar(ch);
+  return buf.MakeString();
+}
+
+CFX_ByteString CPDF_SyntaxParser::ReadHexString() {
+  uint8_t ch;
+  if (!GetNextChar(ch))
+    return CFX_ByteString();
+
+  CFX_ByteTextBuf buf;
+  bool bFirst = true;
+  uint8_t code = 0;
+  while (1) {
+    if (ch == '>')
+      break;
+
+    if (std::isxdigit(ch)) {
+      int val = FXSYS_toHexDigit(ch);
+      if (bFirst) {
+        code = val * 16;
+      } else {
+        code += val;
+        buf.AppendByte(code);
+      }
+      bFirst = !bFirst;
+    }
+
+    if (!GetNextChar(ch))
+      break;
+  }
+  if (!bFirst)
+    buf.AppendByte(code);
+
+  return buf.MakeString();
+}
+
+void CPDF_SyntaxParser::ToNextLine() {
+  uint8_t ch;
+  while (GetNextChar(ch)) {
+    if (ch == '\n')
+      break;
+
+    if (ch == '\r') {
+      GetNextChar(ch);
+      if (ch != '\n')
+        --m_Pos;
+      break;
+    }
+  }
+}
+
+void CPDF_SyntaxParser::ToNextWord() {
+  uint8_t ch;
+  if (!GetNextChar(ch))
+    return;
+
+  while (1) {
+    while (PDFCharIsWhitespace(ch)) {
+      if (!GetNextChar(ch))
+        return;
+    }
+
+    if (ch != '%')
+      break;
+
+    while (1) {
+      if (!GetNextChar(ch))
+        return;
+      if (PDFCharIsLineEnding(ch))
+        break;
+    }
+  }
+  m_Pos--;
+}
+
+CFX_ByteString CPDF_SyntaxParser::GetNextWord(bool* bIsNumber) {
+  GetNextWordInternal(bIsNumber);
+  return CFX_ByteString((const FX_CHAR*)m_WordBuffer, m_WordSize);
+}
+
+CFX_ByteString CPDF_SyntaxParser::GetKeyword() {
+  return GetNextWord(nullptr);
+}
+
+CPDF_Object* CPDF_SyntaxParser::GetObject(CPDF_IndirectObjectHolder* pObjList,
+                                          uint32_t objnum,
+                                          uint32_t gennum,
+                                          FX_BOOL bDecrypt) {
+  CFX_AutoRestorer<int> restorer(&s_CurrentRecursionDepth);
+  if (++s_CurrentRecursionDepth > kParserMaxRecursionDepth)
+    return nullptr;
+
+  FX_FILESIZE SavedObjPos = m_Pos;
+  bool bIsNumber;
+  CFX_ByteString word = GetNextWord(&bIsNumber);
+  if (word.GetLength() == 0)
+    return nullptr;
+
+  if (bIsNumber) {
+    FX_FILESIZE SavedPos = m_Pos;
+    CFX_ByteString nextword = GetNextWord(&bIsNumber);
+    if (bIsNumber) {
+      CFX_ByteString nextword2 = GetNextWord(nullptr);
+      if (nextword2 == "R")
+        return new CPDF_Reference(pObjList, FXSYS_atoui(word.c_str()));
+    }
+    m_Pos = SavedPos;
+    return new CPDF_Number(word.AsStringC());
+  }
+
+  if (word == "true" || word == "false")
+    return new CPDF_Boolean(word == "true");
+
+  if (word == "null")
+    return new CPDF_Null;
+
+  if (word == "(") {
+    CFX_ByteString str = ReadString();
+    if (m_pCryptoHandler && bDecrypt)
+      m_pCryptoHandler->Decrypt(objnum, gennum, str);
+    return new CPDF_String(MaybeIntern(str), FALSE);
+  }
+
+  if (word == "<") {
+    CFX_ByteString str = ReadHexString();
+    if (m_pCryptoHandler && bDecrypt)
+      m_pCryptoHandler->Decrypt(objnum, gennum, str);
+    return new CPDF_String(MaybeIntern(str), TRUE);
+  }
+
+  if (word == "[") {
+    CPDF_Array* pArray = new CPDF_Array;
+    while (CPDF_Object* pObj = GetObject(pObjList, objnum, gennum, true))
+      pArray->Add(pObj);
+
+    return pArray;
+  }
+
+  if (word[0] == '/') {
+    return new CPDF_Name(MaybeIntern(
+        PDF_NameDecode(CFX_ByteStringC(m_WordBuffer + 1, m_WordSize - 1))));
+  }
+
+  if (word == "<<") {
+    int32_t nKeys = 0;
+    FX_FILESIZE dwSignValuePos = 0;
+
+    std::unique_ptr<CPDF_Dictionary, ReleaseDeleter<CPDF_Dictionary>> pDict(
+        new CPDF_Dictionary(m_pPool));
+    while (1) {
+      CFX_ByteString key = GetNextWord(nullptr);
+      if (key.IsEmpty())
+        return nullptr;
+
+      FX_FILESIZE SavedPos = m_Pos - key.GetLength();
+      if (key == ">>")
+        break;
+
+      if (key == "endobj") {
+        m_Pos = SavedPos;
+        break;
+      }
+
+      if (key[0] != '/')
+        continue;
+
+      ++nKeys;
+      key = PDF_NameDecode(key);
+      if (key.IsEmpty())
+        continue;
+
+      if (key == "/Contents")
+        dwSignValuePos = m_Pos;
+
+      CPDF_Object* pObj = GetObject(pObjList, objnum, gennum, true);
+      if (!pObj)
+        continue;
+
+      CFX_ByteString keyNoSlash(key.raw_str() + 1, key.GetLength() - 1);
+      pDict->SetFor(keyNoSlash, pObj);
+    }
+
+    // Only when this is a signature dictionary and has contents, we reset the
+    // contents to the un-decrypted form.
+    if (pDict->IsSignatureDict() && dwSignValuePos) {
+      CFX_AutoRestorer<FX_FILESIZE> save_pos(&m_Pos);
+      m_Pos = dwSignValuePos;
+      pDict->SetFor("Contents", GetObject(pObjList, objnum, gennum, false));
+    }
+
+    FX_FILESIZE SavedPos = m_Pos;
+    CFX_ByteString nextword = GetNextWord(nullptr);
+    if (nextword != "stream") {
+      m_Pos = SavedPos;
+      return pDict.release();
+    }
+    return ReadStream(pDict.release(), objnum, gennum);
+  }
+
+  if (word == ">>")
+    m_Pos = SavedObjPos;
+
+  return nullptr;
+}
+
+CPDF_Object* CPDF_SyntaxParser::GetObjectForStrict(
+    CPDF_IndirectObjectHolder* pObjList,
+    uint32_t objnum,
+    uint32_t gennum) {
+  CFX_AutoRestorer<int> restorer(&s_CurrentRecursionDepth);
+  if (++s_CurrentRecursionDepth > kParserMaxRecursionDepth)
+    return nullptr;
+
+  FX_FILESIZE SavedObjPos = m_Pos;
+  bool bIsNumber;
+  CFX_ByteString word = GetNextWord(&bIsNumber);
+  if (word.GetLength() == 0)
+    return nullptr;
+
+  if (bIsNumber) {
+    FX_FILESIZE SavedPos = m_Pos;
+    CFX_ByteString nextword = GetNextWord(&bIsNumber);
+    if (bIsNumber) {
+      CFX_ByteString nextword2 = GetNextWord(nullptr);
+      if (nextword2 == "R")
+        return new CPDF_Reference(pObjList, FXSYS_atoui(word.c_str()));
+    }
+    m_Pos = SavedPos;
+    return new CPDF_Number(word.AsStringC());
+  }
+
+  if (word == "true" || word == "false")
+    return new CPDF_Boolean(word == "true");
+
+  if (word == "null")
+    return new CPDF_Null;
+
+  if (word == "(") {
+    CFX_ByteString str = ReadString();
+    if (m_pCryptoHandler)
+      m_pCryptoHandler->Decrypt(objnum, gennum, str);
+    return new CPDF_String(MaybeIntern(str), FALSE);
+  }
+
+  if (word == "<") {
+    CFX_ByteString str = ReadHexString();
+    if (m_pCryptoHandler)
+      m_pCryptoHandler->Decrypt(objnum, gennum, str);
+    return new CPDF_String(MaybeIntern(str), TRUE);
+  }
+
+  if (word == "[") {
+    std::unique_ptr<CPDF_Array, ReleaseDeleter<CPDF_Array>> pArray(
+        new CPDF_Array);
+    while (CPDF_Object* pObj = GetObject(pObjList, objnum, gennum, true))
+      pArray->Add(pObj);
+
+    return m_WordBuffer[0] == ']' ? pArray.release() : nullptr;
+  }
+
+  if (word[0] == '/') {
+    return new CPDF_Name(MaybeIntern(
+        PDF_NameDecode(CFX_ByteStringC(m_WordBuffer + 1, m_WordSize - 1))));
+  }
+
+  if (word == "<<") {
+    std::unique_ptr<CPDF_Dictionary, ReleaseDeleter<CPDF_Dictionary>> pDict(
+        new CPDF_Dictionary(m_pPool));
+    while (1) {
+      FX_FILESIZE SavedPos = m_Pos;
+      CFX_ByteString key = GetNextWord(nullptr);
+      if (key.IsEmpty())
+        return nullptr;
+
+      if (key == ">>")
+        break;
+
+      if (key == "endobj") {
+        m_Pos = SavedPos;
+        break;
+      }
+
+      if (key[0] != '/')
+        continue;
+
+      key = PDF_NameDecode(key);
+      std::unique_ptr<CPDF_Object, ReleaseDeleter<CPDF_Object>> obj(
+          GetObject(pObjList, objnum, gennum, true));
+      if (!obj) {
+        uint8_t ch;
+        while (GetNextChar(ch) && ch != 0x0A && ch != 0x0D) {
+          continue;
+        }
+        return nullptr;
+      }
+
+      if (key.GetLength() > 1) {
+        pDict->SetFor(CFX_ByteString(key.c_str() + 1, key.GetLength() - 1),
+                      obj.release());
+      }
+    }
+
+    FX_FILESIZE SavedPos = m_Pos;
+    CFX_ByteString nextword = GetNextWord(nullptr);
+    if (nextword != "stream") {
+      m_Pos = SavedPos;
+      return pDict.release();
+    }
+
+    return ReadStream(pDict.release(), objnum, gennum);
+  }
+
+  if (word == ">>")
+    m_Pos = SavedObjPos;
+
+  return nullptr;
+}
+
+unsigned int CPDF_SyntaxParser::ReadEOLMarkers(FX_FILESIZE pos) {
+  unsigned char byte1 = 0;
+  unsigned char byte2 = 0;
+
+  GetCharAt(pos, byte1);
+  GetCharAt(pos + 1, byte2);
+
+  if (byte1 == '\r' && byte2 == '\n')
+    return 2;
+
+  if (byte1 == '\r' || byte1 == '\n')
+    return 1;
+
+  return 0;
+}
+
+CPDF_Stream* CPDF_SyntaxParser::ReadStream(CPDF_Dictionary* pDict,
+                                           uint32_t objnum,
+                                           uint32_t gennum) {
+  CPDF_Object* pLenObj = pDict->GetObjectFor("Length");
+  FX_FILESIZE len = -1;
+  CPDF_Reference* pLenObjRef = ToReference(pLenObj);
+
+  bool differingObjNum = !pLenObjRef || (pLenObjRef->GetObjList() &&
+                                         pLenObjRef->GetRefObjNum() != objnum);
+  if (pLenObj && differingObjNum)
+    len = pLenObj->GetInteger();
+
+  // Locate the start of stream.
+  ToNextLine();
+  FX_FILESIZE streamStartPos = m_Pos;
+
+  const CFX_ByteStringC kEndStreamStr("endstream");
+  const CFX_ByteStringC kEndObjStr("endobj");
+
+  CPDF_CryptoHandler* pCryptoHandler =
+      objnum == (uint32_t)m_MetadataObjnum ? nullptr : m_pCryptoHandler.get();
+  if (!pCryptoHandler) {
+    FX_BOOL bSearchForKeyword = TRUE;
+    if (len >= 0) {
+      pdfium::base::CheckedNumeric<FX_FILESIZE> pos = m_Pos;
+      pos += len;
+      if (pos.IsValid() && pos.ValueOrDie() < m_FileLen)
+        m_Pos = pos.ValueOrDie();
+
+      m_Pos += ReadEOLMarkers(m_Pos);
+      FXSYS_memset(m_WordBuffer, 0, kEndStreamStr.GetLength() + 1);
+      GetNextWordInternal(nullptr);
+      // Earlier version of PDF specification doesn't require EOL marker before
+      // 'endstream' keyword. If keyword 'endstream' follows the bytes in
+      // specified length, it signals the end of stream.
+      if (FXSYS_memcmp(m_WordBuffer, kEndStreamStr.raw_str(),
+                       kEndStreamStr.GetLength()) == 0) {
+        bSearchForKeyword = FALSE;
+      }
+    }
+
+    if (bSearchForKeyword) {
+      // If len is not available, len needs to be calculated
+      // by searching the keywords "endstream" or "endobj".
+      m_Pos = streamStartPos;
+      FX_FILESIZE endStreamOffset = 0;
+      while (endStreamOffset >= 0) {
+        endStreamOffset = FindTag(kEndStreamStr, 0);
+
+        // Can't find "endstream".
+        if (endStreamOffset < 0)
+          break;
+
+        // Stop searching when "endstream" is found.
+        if (IsWholeWord(m_Pos - kEndStreamStr.GetLength(), m_FileLen,
+                        kEndStreamStr, TRUE)) {
+          endStreamOffset = m_Pos - streamStartPos - kEndStreamStr.GetLength();
+          break;
+        }
+      }
+
+      m_Pos = streamStartPos;
+      FX_FILESIZE endObjOffset = 0;
+      while (endObjOffset >= 0) {
+        endObjOffset = FindTag(kEndObjStr, 0);
+
+        // Can't find "endobj".
+        if (endObjOffset < 0)
+          break;
+
+        // Stop searching when "endobj" is found.
+        if (IsWholeWord(m_Pos - kEndObjStr.GetLength(), m_FileLen, kEndObjStr,
+                        TRUE)) {
+          endObjOffset = m_Pos - streamStartPos - kEndObjStr.GetLength();
+          break;
+        }
+      }
+
+      // Can't find "endstream" or "endobj".
+      if (endStreamOffset < 0 && endObjOffset < 0) {
+        pDict->Release();
+        return nullptr;
+      }
+
+      if (endStreamOffset < 0 && endObjOffset >= 0) {
+        // Correct the position of end stream.
+        endStreamOffset = endObjOffset;
+      } else if (endStreamOffset >= 0 && endObjOffset < 0) {
+        // Correct the position of end obj.
+        endObjOffset = endStreamOffset;
+      } else if (endStreamOffset > endObjOffset) {
+        endStreamOffset = endObjOffset;
+      }
+
+      len = endStreamOffset;
+      int numMarkers = ReadEOLMarkers(streamStartPos + endStreamOffset - 2);
+      if (numMarkers == 2) {
+        len -= 2;
+      } else {
+        numMarkers = ReadEOLMarkers(streamStartPos + endStreamOffset - 1);
+        if (numMarkers == 1) {
+          len -= 1;
+        }
+      }
+
+      if (len < 0) {
+        pDict->Release();
+        return nullptr;
+      }
+      pDict->SetIntegerFor("Length", len);
+    }
+    m_Pos = streamStartPos;
+  }
+
+  if (len < 0) {
+    pDict->Release();
+    return nullptr;
+  }
+
+  uint8_t* pData = nullptr;
+  if (len > 0) {
+    pData = FX_Alloc(uint8_t, len);
+    ReadBlock(pData, len);
+    if (pCryptoHandler) {
+      CFX_BinaryBuf dest_buf;
+      dest_buf.EstimateSize(pCryptoHandler->DecryptGetSize(len));
+
+      void* context = pCryptoHandler->DecryptStart(objnum, gennum);
+      pCryptoHandler->DecryptStream(context, pData, len, dest_buf);
+      pCryptoHandler->DecryptFinish(context, dest_buf);
+
+      FX_Free(pData);
+      pData = dest_buf.GetBuffer();
+      len = dest_buf.GetSize();
+      dest_buf.DetachBuffer();
+    }
+  }
+
+  CPDF_Stream* pStream = new CPDF_Stream(pData, len, pDict);
+  streamStartPos = m_Pos;
+  FXSYS_memset(m_WordBuffer, 0, kEndObjStr.GetLength() + 1);
+
+  GetNextWordInternal(nullptr);
+
+  int numMarkers = ReadEOLMarkers(m_Pos);
+  if (m_WordSize == static_cast<unsigned int>(kEndObjStr.GetLength()) &&
+      numMarkers != 0 &&
+      FXSYS_memcmp(m_WordBuffer, kEndObjStr.raw_str(),
+                   kEndObjStr.GetLength()) == 0) {
+    m_Pos = streamStartPos;
+  }
+  return pStream;
+}
+
+void CPDF_SyntaxParser::InitParser(IFX_FileRead* pFileAccess,
+                                   uint32_t HeaderOffset) {
+  FX_Free(m_pFileBuf);
+
+  m_pFileBuf = FX_Alloc(uint8_t, m_BufSize);
+  m_HeaderOffset = HeaderOffset;
+  m_FileLen = pFileAccess->GetSize();
+  m_Pos = 0;
+  m_pFileAccess = pFileAccess;
+  m_BufOffset = 0;
+  pFileAccess->ReadBlock(
+      m_pFileBuf, 0,
+      (size_t)((FX_FILESIZE)m_BufSize > m_FileLen ? m_FileLen : m_BufSize));
+}
+
+uint32_t CPDF_SyntaxParser::GetDirectNum() {
+  bool bIsNumber;
+  GetNextWordInternal(&bIsNumber);
+  if (!bIsNumber)
+    return 0;
+
+  m_WordBuffer[m_WordSize] = 0;
+  return FXSYS_atoui(reinterpret_cast<const FX_CHAR*>(m_WordBuffer));
+}
+
+bool CPDF_SyntaxParser::IsWholeWord(FX_FILESIZE startpos,
+                                    FX_FILESIZE limit,
+                                    const CFX_ByteStringC& tag,
+                                    FX_BOOL checkKeyword) {
+  const uint32_t taglen = tag.GetLength();
+
+  bool bCheckLeft = !PDFCharIsDelimiter(tag[0]) && !PDFCharIsWhitespace(tag[0]);
+  bool bCheckRight = !PDFCharIsDelimiter(tag[taglen - 1]) &&
+                     !PDFCharIsWhitespace(tag[taglen - 1]);
+
+  uint8_t ch;
+  if (bCheckRight && startpos + (int32_t)taglen <= limit &&
+      GetCharAt(startpos + (int32_t)taglen, ch)) {
+    if (PDFCharIsNumeric(ch) || PDFCharIsOther(ch) ||
+        (checkKeyword && PDFCharIsDelimiter(ch))) {
+      return false;
+    }
+  }
+
+  if (bCheckLeft && startpos > 0 && GetCharAt(startpos - 1, ch)) {
+    if (PDFCharIsNumeric(ch) || PDFCharIsOther(ch) ||
+        (checkKeyword && PDFCharIsDelimiter(ch))) {
+      return false;
+    }
+  }
+  return true;
+}
+
+// TODO(dsinclair): Split into a SearchWordForward and SearchWordBackwards
+// and drop the bool.
+FX_BOOL CPDF_SyntaxParser::SearchWord(const CFX_ByteStringC& tag,
+                                      FX_BOOL bWholeWord,
+                                      FX_BOOL bForward,
+                                      FX_FILESIZE limit) {
+  int32_t taglen = tag.GetLength();
+  if (taglen == 0)
+    return FALSE;
+
+  FX_FILESIZE pos = m_Pos;
+  int32_t offset = 0;
+  if (!bForward)
+    offset = taglen - 1;
+
+  const uint8_t* tag_data = tag.raw_str();
+  uint8_t byte;
+  while (1) {
+    if (bForward) {
+      if (limit && pos >= m_Pos + limit)
+        return FALSE;
+
+      if (!GetCharAt(pos, byte))
+        return FALSE;
+
+    } else {
+      if (limit && pos <= m_Pos - limit)
+        return FALSE;
+
+      if (!GetCharAtBackward(pos, byte))
+        return FALSE;
+    }
+
+    if (byte == tag_data[offset]) {
+      if (bForward) {
+        offset++;
+        if (offset < taglen) {
+          pos++;
+          continue;
+        }
+      } else {
+        offset--;
+        if (offset >= 0) {
+          pos--;
+          continue;
+        }
+      }
+
+      FX_FILESIZE startpos = bForward ? pos - taglen + 1 : pos;
+      if (!bWholeWord || IsWholeWord(startpos, limit, tag, FALSE)) {
+        m_Pos = startpos;
+        return TRUE;
+      }
+    }
+
+    if (bForward) {
+      offset = byte == tag_data[0] ? 1 : 0;
+      pos++;
+    } else {
+      offset = byte == tag_data[taglen - 1] ? taglen - 2 : taglen - 1;
+      pos--;
+    }
+
+    if (pos < 0)
+      return FALSE;
+  }
+
+  return FALSE;
+}
+
+int32_t CPDF_SyntaxParser::SearchMultiWord(const CFX_ByteStringC& tags,
+                                           FX_BOOL bWholeWord,
+                                           FX_FILESIZE limit) {
+  int32_t ntags = 1;
+  for (int i = 0; i < tags.GetLength(); ++i) {
+    if (tags[i] == 0)
+      ++ntags;
+  }
+
+  // Ensure that the input byte string happens to be nul-terminated. This
+  // need not be the case, but the loop below uses this guarantee to put
+  // the last pattern into the vector.
+  ASSERT(tags[tags.GetLength()] == 0);
+  std::vector<SearchTagRecord> patterns(ntags);
+  uint32_t start = 0;
+  uint32_t itag = 0;
+  uint32_t max_len = 0;
+  for (int i = 0; i <= tags.GetLength(); ++i) {
+    if (tags[i] == 0) {
+      uint32_t len = i - start;
+      max_len = std::max(len, max_len);
+      patterns[itag].m_bsTag = tags.Mid(start, len);
+      patterns[itag].m_Offset = 0;
+      start = i + 1;
+      ++itag;
+    }
+  }
+
+  const FX_FILESIZE pos_limit = m_Pos + limit;
+  for (FX_FILESIZE pos = m_Pos; !limit || pos < pos_limit; ++pos) {
+    uint8_t byte;
+    if (!GetCharAt(pos, byte))
+      break;
+
+    for (int i = 0; i < ntags; ++i) {
+      SearchTagRecord& pat = patterns[i];
+      if (pat.m_bsTag[pat.m_Offset] != byte) {
+        pat.m_Offset = (pat.m_bsTag[0] == byte) ? 1 : 0;
+        continue;
+      }
+
+      ++pat.m_Offset;
+      if (pat.m_Offset != pat.m_bsTag.GetLength())
+        continue;
+
+      if (!bWholeWord || IsWholeWord(pos - pat.m_bsTag.GetLength(), limit,
+                                     pat.m_bsTag, FALSE)) {
+        return i;
+      }
+
+      pat.m_Offset = (pat.m_bsTag[0] == byte) ? 1 : 0;
+    }
+  }
+  return -1;
+}
+
+FX_FILESIZE CPDF_SyntaxParser::FindTag(const CFX_ByteStringC& tag,
+                                       FX_FILESIZE limit) {
+  int32_t taglen = tag.GetLength();
+  int32_t match = 0;
+  limit += m_Pos;
+  FX_FILESIZE startpos = m_Pos;
+
+  while (1) {
+    uint8_t ch;
+    if (!GetNextChar(ch))
+      return -1;
+
+    if (ch == tag[match]) {
+      match++;
+      if (match == taglen)
+        return m_Pos - startpos - taglen;
+    } else {
+      match = ch == tag[0] ? 1 : 0;
+    }
+
+    if (limit && m_Pos == limit)
+      return -1;
+  }
+  return -1;
+}
+
+void CPDF_SyntaxParser::SetEncrypt(
+    std::unique_ptr<CPDF_CryptoHandler> pCryptoHandler) {
+  m_pCryptoHandler = std::move(pCryptoHandler);
+}
+
+CFX_ByteString CPDF_SyntaxParser::MaybeIntern(const CFX_ByteString& str) {
+  return m_pPool ? m_pPool->Intern(str) : str;
+}
diff --git a/core/fpdfapi/parser/cpdf_syntax_parser.h b/core/fpdfapi/parser/cpdf_syntax_parser.h
new file mode 100644
index 0000000000..444a94bde1
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_syntax_parser.h
@@ -0,0 +1,101 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#ifndef CORE_FPDFAPI_PARSER_CPDF_SYNTAX_PARSER_H_
+#define CORE_FPDFAPI_PARSER_CPDF_SYNTAX_PARSER_H_
+
+#include <memory>
+
+#include "core/fxcrt/cfx_string_pool_template.h"
+#include "core/fxcrt/cfx_weak_ptr.h"
+#include "core/fxcrt/fx_basic.h"
+
+class CPDF_CryptoHandler;
+class CPDF_Dictionary;
+class CPDF_IndirectObjectHolder;
+class CPDF_Object;
+class CPDF_Stream;
+class IFX_FileRead;
+
+class CPDF_SyntaxParser {
+ public:
+  CPDF_SyntaxParser();
+  explicit CPDF_SyntaxParser(const CFX_WeakPtr<CFX_ByteStringPool>& pPool);
+  ~CPDF_SyntaxParser();
+
+  void InitParser(IFX_FileRead* pFileAccess, uint32_t HeaderOffset);
+
+  FX_FILESIZE SavePos() const { return m_Pos; }
+  void RestorePos(FX_FILESIZE pos) { m_Pos = pos; }
+
+  CPDF_Object* GetObject(CPDF_IndirectObjectHolder* pObjList,
+                         uint32_t objnum,
+                         uint32_t gennum,
+                         FX_BOOL bDecrypt);
+  CPDF_Object* GetObjectForStrict(CPDF_IndirectObjectHolder* pObjList,
+                                  uint32_t objnum,
+                                  uint32_t gennum);
+  CFX_ByteString GetKeyword();
+
+  void ToNextLine();
+  void ToNextWord();
+
+  FX_BOOL SearchWord(const CFX_ByteStringC& word,
+                     FX_BOOL bWholeWord,
+                     FX_BOOL bForward,
+                     FX_FILESIZE limit);
+  int SearchMultiWord(const CFX_ByteStringC& words,
+                      FX_BOOL bWholeWord,
+                      FX_FILESIZE limit);
+  FX_FILESIZE FindTag(const CFX_ByteStringC& tag, FX_FILESIZE limit);
+
+  void SetEncrypt(std::unique_ptr<CPDF_CryptoHandler> pCryptoHandler);
+
+  FX_BOOL ReadBlock(uint8_t* pBuf, uint32_t size);
+  FX_BOOL GetCharAt(FX_FILESIZE pos, uint8_t& ch);
+  CFX_ByteString GetNextWord(bool* bIsNumber);
+
+ private:
+  friend class CPDF_Parser;
+  friend class CPDF_DataAvail;
+  friend class cpdf_syntax_parser_ReadHexString_Test;
+
+  static const int kParserMaxRecursionDepth = 64;
+  static int s_CurrentRecursionDepth;
+
+  uint32_t GetDirectNum();
+  FX_BOOL GetNextChar(uint8_t& ch);
+  FX_BOOL GetCharAtBackward(FX_FILESIZE pos, uint8_t& ch);
+  void GetNextWordInternal(bool* bIsNumber);
+  bool IsWholeWord(FX_FILESIZE startpos,
+                   FX_FILESIZE limit,
+                   const CFX_ByteStringC& tag,
+                   FX_BOOL checkKeyword);
+
+  CFX_ByteString ReadString();
+  CFX_ByteString ReadHexString();
+  unsigned int ReadEOLMarkers(FX_FILESIZE pos);
+  CPDF_Stream* ReadStream(CPDF_Dictionary* pDict,
+                          uint32_t objnum,
+                          uint32_t gennum);
+
+  CFX_ByteString MaybeIntern(const CFX_ByteString& str);
+
+  FX_FILESIZE m_Pos;
+  int m_MetadataObjnum;
+  IFX_FileRead* m_pFileAccess;
+  FX_FILESIZE m_HeaderOffset;
+  FX_FILESIZE m_FileLen;
+  uint8_t* m_pFileBuf;
+  uint32_t m_BufSize;
+  FX_FILESIZE m_BufOffset;
+  std::unique_ptr<CPDF_CryptoHandler> m_pCryptoHandler;
+  uint8_t m_WordBuffer[257];
+  uint32_t m_WordSize;
+  CFX_WeakPtr<CFX_ByteStringPool> m_pPool;
+};
+
+#endif  // CORE_FPDFAPI_PARSER_CPDF_SYNTAX_PARSER_H_
diff --git a/core/fpdfapi/parser/cpdf_syntax_parser_unittest.cpp b/core/fpdfapi/parser/cpdf_syntax_parser_unittest.cpp
new file mode 100644
index 0000000000..45a0698078
--- /dev/null
+++ b/core/fpdfapi/parser/cpdf_syntax_parser_unittest.cpp
@@ -0,0 +1,171 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <limits>
+#include <string>
+
+#include "core/fpdfapi/parser/cpdf_parser.h"
+#include "core/fpdfapi/parser/cpdf_syntax_parser.h"
+#include "core/fxcrt/fx_ext.h"
+#include "core/fxcrt/fx_stream.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "testing/utils/path_service.h"
+
+TEST(cpdf_syntax_parser, ReadHexString) {
+  {
+    // Empty string.
+    uint8_t data[] = "";
+    ScopedFileStream stream(FX_CreateMemoryStream(data, 0, FALSE));
+
+    CPDF_SyntaxParser parser;
+    parser.InitParser(stream.get(), 0);
+    EXPECT_EQ("", parser.ReadHexString());
+    EXPECT_EQ(0, parser.SavePos());
+  }
+
+  {
+    // Blank string.
+    uint8_t data[] = "  ";
+    ScopedFileStream stream(FX_CreateMemoryStream(data, 2, FALSE));
+
+    CPDF_SyntaxParser parser;
+    parser.InitParser(stream.get(), 0);
+    EXPECT_EQ("", parser.ReadHexString());
+    EXPECT_EQ(2, parser.SavePos());
+  }
+
+  {
+    // Skips unknown characters.
+    uint8_t data[] = "z12b";
+    ScopedFileStream stream(FX_CreateMemoryStream(data, 4, FALSE));
+
+    CPDF_SyntaxParser parser;
+    parser.InitParser(stream.get(), 0);
+    EXPECT_EQ("\x12\xb0", parser.ReadHexString());
+    EXPECT_EQ(4, parser.SavePos());
+  }
+
+  {
+    // Skips unknown characters.
+    uint8_t data[] = "*<&*#$^&@1";
+    ScopedFileStream stream(FX_CreateMemoryStream(data, 10, FALSE));
+
+    CPDF_SyntaxParser parser;
+    parser.InitParser(stream.get(), 0);
+    EXPECT_EQ("\x10", parser.ReadHexString());
+    EXPECT_EQ(10, parser.SavePos());
+  }
+
+  {
+    // Skips unknown characters.
+    uint8_t data[] = "\x80zab";
+    ScopedFileStream stream(FX_CreateMemoryStream(data, 4, FALSE));
+
+    CPDF_SyntaxParser parser;
+    parser.InitParser(stream.get(), 0);
+    EXPECT_EQ("\xab", parser.ReadHexString());
+    EXPECT_EQ(4, parser.SavePos());
+  }
+
+  {
+    // Skips unknown characters.
+    uint8_t data[] = "\xffzab";
+    ScopedFileStream stream(FX_CreateMemoryStream(data, 4, FALSE));
+
+    CPDF_SyntaxParser parser;
+    parser.InitParser(stream.get(), 0);
+    EXPECT_EQ("\xab", parser.ReadHexString());
+    EXPECT_EQ(4, parser.SavePos());
+  }
+
+  {
+    // Regular conversion.
+    uint8_t data[] = "1A2b>abcd";
+    ScopedFileStream stream(FX_CreateMemoryStream(data, 9, FALSE));
+
+    CPDF_SyntaxParser parser;
+    parser.InitParser(stream.get(), 0);
+    EXPECT_EQ("\x1a\x2b", parser.ReadHexString());
+    EXPECT_EQ(5, parser.SavePos());
+  }
+
+  {
+    // Position out of bounds.
+    uint8_t data[] = "12ab>";
+    ScopedFileStream stream(FX_CreateMemoryStream(data, 5, FALSE));
+
+    CPDF_SyntaxParser parser;
+    parser.InitParser(stream.get(), 0);
+    parser.RestorePos(5);
+    EXPECT_EQ("", parser.ReadHexString());
+
+    parser.RestorePos(6);
+    EXPECT_EQ("", parser.ReadHexString());
+
+    parser.RestorePos(-1);
+    EXPECT_EQ("", parser.ReadHexString());
+
+    parser.RestorePos(std::numeric_limits<FX_FILESIZE>::max());
+    EXPECT_EQ("", parser.ReadHexString());
+
+    // Check string still parses when set to 0.
+    parser.RestorePos(0);
+    EXPECT_EQ("\x12\xab", parser.ReadHexString());
+  }
+
+  {
+    // Missing ending >.
+    uint8_t data[] = "1A2b";
+    ScopedFileStream stream(FX_CreateMemoryStream(data, 4, FALSE));
+
+    CPDF_SyntaxParser parser;
+    parser.InitParser(stream.get(), 0);
+    EXPECT_EQ("\x1a\x2b", parser.ReadHexString());
+    EXPECT_EQ(4, parser.SavePos());
+  }
+
+  {
+    // Missing ending >.
+    uint8_t data[] = "12abz";
+    ScopedFileStream stream(FX_CreateMemoryStream(data, 5, FALSE));
+
+    CPDF_SyntaxParser parser;
+    parser.InitParser(stream.get(), 0);
+    EXPECT_EQ("\x12\xab", parser.ReadHexString());
+    EXPECT_EQ(5, parser.SavePos());
+  }
+
+  {
+    // Uneven number of bytes.
+    uint8_t data[] = "1A2>asdf";
+    ScopedFileStream stream(FX_CreateMemoryStream(data, 8, FALSE));
+
+    CPDF_SyntaxParser parser;
+    parser.InitParser(stream.get(), 0);
+    EXPECT_EQ("\x1a\x20", parser.ReadHexString());
+    EXPECT_EQ(4, parser.SavePos());
+  }
+
+  {
+    // Uneven number of bytes.
+    uint8_t data[] = "1A2zasdf";
+    ScopedFileStream stream(FX_CreateMemoryStream(data, 8, FALSE));
+
+    CPDF_SyntaxParser parser;
+    parser.InitParser(stream.get(), 0);
+    EXPECT_EQ("\x1a\x2a\xdf", parser.ReadHexString());
+    EXPECT_EQ(8, parser.SavePos());
+  }
+
+  {
+    // Just ending character.
+    uint8_t data[] = ">";
+    ScopedFileStream stream(FX_CreateMemoryStream(data, 1, FALSE));
+
+    CPDF_SyntaxParser parser;
+    parser.InitParser(stream.get(), 0);
+    EXPECT_EQ("", parser.ReadHexString());
+    EXPECT_EQ(1, parser.SavePos());
+  }
+}
diff --git a/core/fpdfapi/parser/fpdf_parser_decode.cpp b/core/fpdfapi/parser/fpdf_parser_decode.cpp
new file mode 100644
index 0000000000..88712c9760
--- /dev/null
+++ b/core/fpdfapi/parser/fpdf_parser_decode.cpp
@@ -0,0 +1,575 @@
+// Copyright 2014 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#include "core/fpdfapi/parser/fpdf_parser_decode.h"
+
+#include <limits.h>
+
+#include <algorithm>
+#include <utility>
+#include <vector>
+
+#include "core/fpdfapi/cpdf_modulemgr.h"
+#include "core/fpdfapi/parser/cpdf_array.h"
+#include "core/fpdfapi/parser/cpdf_dictionary.h"
+#include "core/fpdfapi/parser/fpdf_parser_utility.h"
+#include "core/fxcodec/fx_codec.h"
+#include "core/fxcrt/fx_ext.h"
+#include "third_party/base/stl_util.h"
+
+namespace {
+
+const uint32_t kMaxStreamSize = 20 * 1024 * 1024;
+
+bool CheckFlateDecodeParams(int Colors, int BitsPerComponent, int Columns) {
+  if (Colors < 0 || BitsPerComponent < 0 || Columns < 0)
+    return false;
+
+  int check = Columns;
+  if (check > 0 && Colors > INT_MAX / check)
+    return false;
+
+  check *= Colors;
+  if (check > 0 && BitsPerComponent > INT_MAX / check)
+    return false;
+
+  return check * BitsPerComponent <= INT_MAX - 7;
+}
+
+}  // namespace
+
+const uint16_t PDFDocEncoding[256] = {
+    0x0000, 0x0001, 0x0002, 0x0003, 0x0004, 0x0005, 0x0006, 0x0007, 0x0008,
+    0x0009, 0x000a, 0x000b, 0x000c, 0x000d, 0x000e, 0x000f, 0x0010, 0x0011,
+    0x0012, 0x0013, 0x0014, 0x0015, 0x0016, 0x0017, 0x02d8, 0x02c7, 0x02c6,
+    0x02d9, 0x02dd, 0x02db, 0x02da, 0x02dc, 0x0020, 0x0021, 0x0022, 0x0023,
+    0x0024, 0x0025, 0x0026, 0x0027, 0x0028, 0x0029, 0x002a, 0x002b, 0x002c,
+    0x002d, 0x002e, 0x002f, 0x0030, 0x0031, 0x0032, 0x0033, 0x0034, 0x0035,
+    0x0036, 0x0037, 0x0038, 0x0039, 0x003a, 0x003b, 0x003c, 0x003d, 0x003e,
+    0x003f, 0x0040, 0x0041, 0x0042, 0x0043, 0x0044, 0x0045, 0x0046, 0x0047,
+    0x0048, 0x0049, 0x004a, 0x004b, 0x004c, 0x004d, 0x004e, 0x004f, 0x0050,
+    0x0051, 0x0052, 0x0053, 0x0054, 0x0055, 0x0056, 0x0057, 0x0058, 0x0059,
+    0x005a, 0x005b, 0x005c, 0x005d, 0x005e, 0x005f, 0x0060, 0x0061, 0x0062,
+    0x0063, 0x0064, 0x0065, 0x0066, 0x0067, 0x0068, 0x0069, 0x006a, 0x006b,
+    0x006c, 0x006d, 0x006e, 0x006f, 0x0070, 0x0071, 0x0072, 0x0073, 0x0074,
+    0x0075, 0x0076, 0x0077, 0x0078, 0x0079, 0x007a, 0x007b, 0x007c, 0x007d,
+    0x007e, 0x0000, 0x2022, 0x2020, 0x2021, 0x2026, 0x2014, 0x2013, 0x0192,
+    0x2044, 0x2039, 0x203a, 0x2212, 0x2030, 0x201e, 0x201c, 0x201d, 0x2018,
+    0x2019, 0x201a, 0x2122, 0xfb01, 0xfb02, 0x0141, 0x0152, 0x0160, 0x0178,
+    0x017d, 0x0131, 0x0142, 0x0153, 0x0161, 0x017e, 0x0000, 0x20ac, 0x00a1,
+    0x00a2, 0x00a3, 0x00a4, 0x00a5, 0x00a6, 0x00a7, 0x00a8, 0x00a9, 0x00aa,
+    0x00ab, 0x00ac, 0x0000, 0x00ae, 0x00af, 0x00b0, 0x00b1, 0x00b2, 0x00b3,
+    0x00b4, 0x00b5, 0x00b6, 0x00b7, 0x00b8, 0x00b9, 0x00ba, 0x00bb, 0x00bc,
+    0x00bd, 0x00be, 0x00bf, 0x00c0, 0x00c1, 0x00c2, 0x00c3, 0x00c4, 0x00c5,
+    0x00c6, 0x00c7, 0x00c8, 0x00c9, 0x00ca, 0x00cb, 0x00cc, 0x00cd, 0x00ce,
+    0x00cf, 0x00d0, 0x00d1, 0x00d2, 0x00d3, 0x00d4, 0x00d5, 0x00d6, 0x00d7,
+    0x00d8, 0x00d9, 0x00da, 0x00db, 0x00dc, 0x00dd, 0x00de, 0x00df, 0x00e0,
+    0x00e1, 0x00e2, 0x00e3, 0x00e4, 0x00e5, 0x00e6, 0x00e7, 0x00e8, 0x00e9,
+    0x00ea, 0x00eb, 0x00ec, 0x00ed, 0x00ee, 0x00ef, 0x00f0, 0x00f1, 0x00f2,
+    0x00f3, 0x00f4, 0x00f5, 0x00f6, 0x00f7, 0x00f8, 0x00f9, 0x00fa, 0x00fb,
+    0x00fc, 0x00fd, 0x00fe, 0x00ff};
+
+uint32_t A85Decode(const uint8_t* src_buf,
+                   uint32_t src_size,
+                   uint8_t*& dest_buf,
+                   uint32_t& dest_size) {
+  dest_size = 0;
+  dest_buf = nullptr;
+  if (src_size == 0)
+    return 0;
+
+  // Count legal characters and zeros.
+  uint32_t zcount = 0;
+  uint32_t pos = 0;
+  while (pos < src_size) {
+    uint8_t ch = src_buf[pos];
+    if (ch == 'z') {
+      zcount++;
+    } else if ((ch < '!' || ch > 'u') && !PDFCharIsLineEnding(ch) &&
+               ch != ' ' && ch != '\t') {
+      break;
+    }
+    pos++;
+  }
+  // No content to decode.
+  if (pos == 0)
+    return 0;
+
+  // Count the space needed to contain non-zero characters. The encoding ratio
+  // of Ascii85 is 4:5.
+  uint32_t space_for_non_zeroes = (pos - zcount) / 5 * 4 + 4;
+  if (zcount > (UINT_MAX - space_for_non_zeroes) / 4) {
+    return (uint32_t)-1;
+  }
+  dest_buf = FX_Alloc(uint8_t, zcount * 4 + space_for_non_zeroes);
+  size_t state = 0;
+  uint32_t res = 0;
+  pos = dest_size = 0;
+  while (pos < src_size) {
+    uint8_t ch = src_buf[pos++];
+    if (PDFCharIsLineEnding(ch) || ch == ' ' || ch == '\t')
+      continue;
+
+    if (ch == 'z') {
+      FXSYS_memset(dest_buf + dest_size, 0, 4);
+      state = 0;
+      res = 0;
+      dest_size += 4;
+    } else if (ch >= '!' && ch <= 'u') {
+      res = res * 85 + ch - 33;
+      state++;
+      if (state == 5) {
+        for (size_t i = 0; i < 4; i++) {
+          dest_buf[dest_size++] = (uint8_t)(res >> (3 - i) * 8);
+        }
+        state = 0;
+        res = 0;
+      }
+    } else {
+      // The end or illegal character.
+      break;
+    }
+  }
+  // Handle partial group.
+  if (state) {
+    for (size_t i = state; i < 5; i++)
+      res = res * 85 + 84;
+    for (size_t i = 0; i < state - 1; i++)
+      dest_buf[dest_size++] = (uint8_t)(res >> (3 - i) * 8);
+  }
+  if (pos < src_size && src_buf[pos] == '>')
+    pos++;
+  return pos;
+}
+
+uint32_t HexDecode(const uint8_t* src_buf,
+                   uint32_t src_size,
+                   uint8_t*& dest_buf,
+                   uint32_t& dest_size) {
+  dest_size = 0;
+  if (src_size == 0) {
+    dest_buf = nullptr;
+    return 0;
+  }
+
+  uint32_t i = 0;
+  // Find the end of data.
+  while (i < src_size && src_buf[i] != '>')
+    i++;
+
+  dest_buf = FX_Alloc(uint8_t, i / 2 + 1);
+  bool bFirst = true;
+  for (i = 0; i < src_size; i++) {
+    uint8_t ch = src_buf[i];
+    if (PDFCharIsLineEnding(ch) || ch == ' ' || ch == '\t')
+      continue;
+
+    if (ch == '>') {
+      ++i;
+      break;
+    }
+    if (!std::isxdigit(ch))
+      continue;
+
+    int digit = FXSYS_toHexDigit(ch);
+    if (bFirst)
+      dest_buf[dest_size] = digit * 16;
+    else
+      dest_buf[dest_size++] += digit;
+
+    bFirst = !bFirst;
+  }
+  if (!bFirst)
+    dest_size++;
+  return i;
+}
+
+uint32_t RunLengthDecode(const uint8_t* src_buf,
+                         uint32_t src_size,
+                         uint8_t*& dest_buf,
+                         uint32_t& dest_size) {
+  uint32_t i = 0;
+  dest_size = 0;
+  while (i < src_size) {
+    if (src_buf[i] == 128)
+      break;
+
+    uint32_t old = dest_size;
+    if (src_buf[i] < 128) {
+      dest_size += src_buf[i] + 1;
+      if (dest_size < old)
+        return FX_INVALID_OFFSET;
+      i += src_buf[i] + 2;
+    } else {
+      dest_size += 257 - src_buf[i];
+      if (dest_size < old)
+        return FX_INVALID_OFFSET;
+      i += 2;
+    }
+  }
+  if (dest_size >= kMaxStreamSize)
+    return FX_INVALID_OFFSET;
+
+  dest_buf = FX_Alloc(uint8_t, dest_size);
+  i = 0;
+  int dest_count = 0;
+  while (i < src_size) {
+    if (src_buf[i] == 128)
+      break;
+
+    if (src_buf[i] < 128) {
+      uint32_t copy_len = src_buf[i] + 1;
+      uint32_t buf_left = src_size - i - 1;
+      if (buf_left < copy_len) {
+        uint32_t delta = copy_len - buf_left;
+        copy_len = buf_left;
+        FXSYS_memset(dest_buf + dest_count + copy_len, '\0', delta);
+      }
+      FXSYS_memcpy(dest_buf + dest_count, src_buf + i + 1, copy_len);
+      dest_count += src_buf[i] + 1;
+      i += src_buf[i] + 2;
+    } else {
+      int fill = 0;
+      if (i < src_size - 1) {
+        fill = src_buf[i + 1];
+      }
+      FXSYS_memset(dest_buf + dest_count, fill, 257 - src_buf[i]);
+      dest_count += 257 - src_buf[i];
+      i += 2;
+    }
+  }
+
+  return std::min(i + 1, src_size);
+}
+
+CCodec_ScanlineDecoder* FPDFAPI_CreateFaxDecoder(
+    const uint8_t* src_buf,
+    uint32_t src_size,
+    int width,
+    int height,
+    const CPDF_Dictionary* pParams) {
+  int K = 0;
+  bool EndOfLine = false;
+  bool ByteAlign = false;
+  bool BlackIs1 = false;
+  int Columns = 1728;
+  int Rows = 0;
+  if (pParams) {
+    K = pParams->GetIntegerFor("K");
+    EndOfLine = !!pParams->GetIntegerFor("EndOfLine");
+    ByteAlign = !!pParams->GetIntegerFor("EncodedByteAlign");
+    BlackIs1 = !!pParams->GetIntegerFor("BlackIs1");
+    Columns = pParams->GetIntegerFor("Columns", 1728);
+    Rows = pParams->GetIntegerFor("Rows");
+    if (Rows > USHRT_MAX) {
+      Rows = 0;
+    }
+  }
+  return CPDF_ModuleMgr::Get()->GetFaxModule()->CreateDecoder(
+      src_buf, src_size, width, height, K, EndOfLine, ByteAlign, BlackIs1,
+      Columns, Rows);
+}
+
+CCodec_ScanlineDecoder* FPDFAPI_CreateFlateDecoder(
+    const uint8_t* src_buf,
+    uint32_t src_size,
+    int width,
+    int height,
+    int nComps,
+    int bpc,
+    const CPDF_Dictionary* pParams) {
+  int predictor = 0;
+  int Colors = 0, BitsPerComponent = 0, Columns = 0;
+  if (pParams) {
+    predictor = pParams->GetIntegerFor("Predictor");
+    Colors = pParams->GetIntegerFor("Colors", 1);
+    BitsPerComponent = pParams->GetIntegerFor("BitsPerComponent", 8);
+    Columns = pParams->GetIntegerFor("Columns", 1);
+    if (!CheckFlateDecodeParams(Colors, BitsPerComponent, Columns)) {
+      return nullptr;
+    }
+  }
+  return CPDF_ModuleMgr::Get()->GetFlateModule()->CreateDecoder(
+      src_buf, src_size, width, height, nComps, bpc, predictor, Colors,
+      BitsPerComponent, Columns);
+}
+
+uint32_t FPDFAPI_FlateOrLZWDecode(FX_BOOL bLZW,
+                                  const uint8_t* src_buf,
+                                  uint32_t src_size,
+                                  CPDF_Dictionary* pParams,
+                                  uint32_t estimated_size,
+                                  uint8_t*& dest_buf,
+                                  uint32_t& dest_size) {
+  int predictor = 0;
+  FX_BOOL bEarlyChange = TRUE;
+  int Colors = 0, BitsPerComponent = 0, Columns = 0;
+  if (pParams) {
+    predictor = pParams->GetIntegerFor("Predictor");
+    bEarlyChange = pParams->GetIntegerFor("EarlyChange", 1);
+    Colors = pParams->GetIntegerFor("Colors", 1);
+    BitsPerComponent = pParams->GetIntegerFor("BitsPerComponent", 8);
+    Columns = pParams->GetIntegerFor("Columns", 1);
+    if (!CheckFlateDecodeParams(Colors, BitsPerComponent, Columns)) {
+      return (uint32_t)-1;
+    }
+  }
+  return CPDF_ModuleMgr::Get()->GetFlateModule()->FlateOrLZWDecode(
+      bLZW, src_buf, src_size, bEarlyChange, predictor, Colors,
+      BitsPerComponent, Columns, estimated_size, dest_buf, dest_size);
+}
+
+FX_BOOL PDF_DataDecode(const uint8_t* src_buf,
+                       uint32_t src_size,
+                       const CPDF_Dictionary* pDict,
+                       uint8_t*& dest_buf,
+                       uint32_t& dest_size,
+                       CFX_ByteString& ImageEncoding,
+                       CPDF_Dictionary*& pImageParms,
+                       uint32_t last_estimated_size,
+                       FX_BOOL bImageAcc) {
+  CPDF_Object* pDecoder = pDict ? pDict->GetDirectObjectFor("Filter") : nullptr;
+  if (!pDecoder || (!pDecoder->IsArray() && !pDecoder->IsName()))
+    return FALSE;
+
+  CPDF_Object* pParams =
+      pDict ? pDict->GetDirectObjectFor("DecodeParms") : nullptr;
+
+  std::vector<std::pair<CFX_ByteString, CPDF_Object*>> DecoderArray;
+  if (CPDF_Array* pDecoders = pDecoder->AsArray()) {
+    CPDF_Array* pParamsArray = ToArray(pParams);
+    for (size_t i = 0; i < pDecoders->GetCount(); i++) {
+      DecoderArray.push_back(
+          {pDecoders->GetStringAt(i),
+           pParamsArray ? pParamsArray->GetDictAt(i) : nullptr});
+    }
+  } else {
+    DecoderArray.push_back(
+        {pDecoder->GetString(), pParams ? pParams->GetDict() : nullptr});
+  }
+  uint8_t* last_buf = const_cast<uint8_t*>(src_buf);
+  uint32_t last_size = src_size;
+  int nSize = pdfium::CollectionSize<int>(DecoderArray);
+  for (int i = 0; i < nSize; i++) {
+    int estimated_size = i == nSize - 1 ? last_estimated_size : 0;
+    CFX_ByteString decoder = DecoderArray[i].first;
+    CPDF_Dictionary* pParam = ToDictionary(DecoderArray[i].second);
+    uint8_t* new_buf = nullptr;
+    uint32_t new_size = (uint32_t)-1;
+    int offset = -1;
+    if (decoder == "FlateDecode" || decoder == "Fl") {
+      if (bImageAcc && i == nSize - 1) {
+        ImageEncoding = "FlateDecode";
+        dest_buf = (uint8_t*)last_buf;
+        dest_size = last_size;
+        pImageParms = pParam;
+        return TRUE;
+      }
+      offset = FPDFAPI_FlateOrLZWDecode(FALSE, last_buf, last_size, pParam,
+                                        estimated_size, new_buf, new_size);
+    } else if (decoder == "LZWDecode" || decoder == "LZW") {
+      offset = FPDFAPI_FlateOrLZWDecode(TRUE, last_buf, last_size, pParam,
+                                        estimated_size, new_buf, new_size);
+    } else if (decoder == "ASCII85Decode" || decoder == "A85") {
+      offset = A85Decode(last_buf, last_size, new_buf, new_size);
+    } else if (decoder == "ASCIIHexDecode" || decoder == "AHx") {
+      offset = HexDecode(last_buf, last_size, new_buf, new_size);
+    } else if (decoder == "RunLengthDecode" || decoder == "RL") {
+      if (bImageAcc && i == nSize - 1) {
+        ImageEncoding = "RunLengthDecode";
+        dest_buf = (uint8_t*)last_buf;
+        dest_size = last_size;
+        pImageParms = pParam;
+        return TRUE;
+      }
+      offset = RunLengthDecode(last_buf, last_size, new_buf, new_size);
+    } else if (decoder == "Crypt") {
+      continue;
+    } else {
+      // If we get here, assume it's an image decoder.
+      if (decoder == "DCT") {
+        decoder = "DCTDecode";
+      } else if (decoder == "CCF") {
+        decoder = "CCITTFaxDecode";
+      }
+      ImageEncoding = decoder;
+      pImageParms = pParam;
+      dest_buf = (uint8_t*)last_buf;
+      dest_size = last_size;
+      if (CPDF_Array* pDecoders = pDecoder->AsArray())
+        pDecoders->RemoveAt(i + 1, pDecoders->GetCount() - i - 1);
+      return TRUE;
+    }
+    if (last_buf != src_buf) {
+      FX_Free(last_buf);
+    }
+    if (offset == -1) {
+      FX_Free(new_buf);
+      return FALSE;
+    }
+    last_buf = new_buf;
+    last_size = new_size;
+  }
+  ImageEncoding = "";
+  pImageParms = nullptr;
+  dest_buf = last_buf;
+  dest_size = last_size;
+  return TRUE;
+}
+
+CFX_WideString PDF_DecodeText(const uint8_t* src_data, uint32_t src_len) {
+  CFX_WideString result;
+  if (src_len >= 2 && ((src_data[0] == 0xfe && src_data[1] == 0xff) ||
+                       (src_data[0] == 0xff && src_data[1] == 0xfe))) {
+    bool bBE = src_data[0] == 0xfe;
+    uint32_t max_chars = (src_len - 2) / 2;
+    if (!max_chars) {
+      return result;
+    }
+    if (src_data[0] == 0xff) {
+      bBE = !src_data[2];
+    }
+    FX_WCHAR* dest_buf = result.GetBuffer(max_chars);
+    const uint8_t* uni_str = src_data + 2;
+    int dest_pos = 0;
+    for (uint32_t i = 0; i < max_chars * 2; i += 2) {
+      uint16_t unicode = bBE ? (uni_str[i] << 8 | uni_str[i + 1])
+                             : (uni_str[i + 1] << 8 | uni_str[i]);
+      if (unicode == 0x1b) {
+        i += 2;
+        while (i < max_chars * 2) {
+          uint16_t unicode2 = bBE ? (uni_str[i] << 8 | uni_str[i + 1])
+                                  : (uni_str[i + 1] << 8 | uni_str[i]);
+          i += 2;
+          if (unicode2 == 0x1b)
+            break;
+        }
+      } else {
+        dest_buf[dest_pos++] = unicode;
+      }
+    }
+    result.ReleaseBuffer(dest_pos);
+  } else {
+    FX_WCHAR* dest_buf = result.GetBuffer(src_len);
+    for (uint32_t i = 0; i < src_len; i++)
+      dest_buf[i] = PDFDocEncoding[src_data[i]];
+    result.ReleaseBuffer(src_len);
+  }
+  return result;
+}
+
+CFX_WideString PDF_DecodeText(const CFX_ByteString& bstr) {
+  return PDF_DecodeText((const uint8_t*)bstr.c_str(), bstr.GetLength());
+}
+
+CFX_ByteString PDF_EncodeText(const FX_WCHAR* pString, int len) {
+  if (len == -1) {
+    len = FXSYS_wcslen(pString);
+  }
+  CFX_ByteString result;
+  FX_CHAR* dest_buf1 = result.GetBuffer(len);
+  int i;
+  for (i = 0; i < len; i++) {
+    int code;
+    for (code = 0; code < 256; code++)
+      if (PDFDocEncoding[code] == pString[i]) {
+        break;
+      }
+    if (code == 256) {
+      break;
+    }
+    dest_buf1[i] = code;
+  }
+  result.ReleaseBuffer(i);
+  if (i == len) {
+    return result;
+  }
+
+  if (len > INT_MAX / 2 - 1) {
+    result.ReleaseBuffer(0);
+    return result;
+  }
+
+  int encLen = len * 2 + 2;
+
+  uint8_t* dest_buf2 = (uint8_t*)result.GetBuffer(encLen);
+  dest_buf2[0] = 0xfe;
+  dest_buf2[1] = 0xff;
+  dest_buf2 += 2;
+  for (int j = 0; j < len; j++) {
+    *dest_buf2++ = pString[i] >> 8;
+    *dest_buf2++ = (uint8_t)pString[j];
+  }
+  result.ReleaseBuffer(encLen);
+  return result;
+}
+
+CFX_ByteString PDF_EncodeText(const CFX_WideString& str) {
+  return PDF_EncodeText(str.c_str(), str.GetLength());
+}
+
+CFX_ByteString PDF_EncodeString(const CFX_ByteString& src, FX_BOOL bHex) {
+  CFX_ByteTextBuf result;
+  int srclen = src.GetLength();
+  if (bHex) {
+    result.AppendChar('<');
+    for (int i = 0; i < srclen; i++) {
+      result.AppendChar("0123456789ABCDEF"[src[i] / 16]);
+      result.AppendChar("0123456789ABCDEF"[src[i] % 16]);
+    }
+    result.AppendChar('>');
+    return result.MakeString();
+  }
+  result.AppendChar('(');
+  for (int i = 0; i < srclen; i++) {
+    uint8_t ch = src[i];
+    if (ch == 0x0a) {
+      result << "\\n";
+      continue;
+    }
+    if (ch == 0x0d) {
+      result << "\\r";
+      continue;
+    }
+    if (ch == ')' || ch == '\\' || ch == '(')
+      result.AppendChar('\\');
+    result.AppendChar(ch);
+  }
+  result.AppendChar(')');
+  return result.MakeString();
+}
+
+bool FlateEncode(const uint8_t* src_buf,
+                 uint32_t src_size,
+                 uint8_t** dest_buf,
+                 uint32_t* dest_size) {
+  CCodec_ModuleMgr* pEncoders = CPDF_ModuleMgr::Get()->GetCodecModule();
+  return pEncoders &&
+         pEncoders->GetFlateModule()->Encode(src_buf, src_size, dest_buf,
+                                             dest_size);
+}
+
+bool PngEncode(const uint8_t* src_buf,
+               uint32_t src_size,
+               uint8_t** dest_buf,
+               uint32_t* dest_size) {
+  CCodec_ModuleMgr* pEncoders = CPDF_ModuleMgr::Get()->GetCodecModule();
+  return pEncoders &&
+         pEncoders->GetFlateModule()->PngEncode(src_buf, src_size, dest_buf,
+                                                dest_size);
+}
+
+uint32_t FlateDecode(const uint8_t* src_buf,
+                     uint32_t src_size,
+                     uint8_t*& dest_buf,
+                     uint32_t& dest_size) {
+  CCodec_ModuleMgr* pEncoders = CPDF_ModuleMgr::Get()->GetCodecModule();
+  if (pEncoders) {
+    return pEncoders->GetFlateModule()->FlateOrLZWDecode(
+        FALSE, src_buf, src_size, FALSE, 0, 0, 0, 0, 0, dest_buf, dest_size);
+  }
+  return 0;
+}
diff --git a/core/fpdfapi/parser/fpdf_parser_decode.h b/core/fpdfapi/parser/fpdf_parser_decode.h
new file mode 100644
index 0000000000..3a5d532831
--- /dev/null
+++ b/core/fpdfapi/parser/fpdf_parser_decode.h
@@ -0,0 +1,77 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#ifndef CORE_FPDFAPI_PARSER_FPDF_PARSER_DECODE_H_
+#define CORE_FPDFAPI_PARSER_FPDF_PARSER_DECODE_H_
+
+#include "core/fxcrt/fx_basic.h"
+
+class CPDF_Dictionary;
+
+// Indexed by 8-bit char code, contains unicode code points.
+extern const uint16_t PDFDocEncoding[256];
+
+CFX_ByteString PDF_NameDecode(const CFX_ByteStringC& orig);
+CFX_ByteString PDF_NameDecode(const CFX_ByteString& orig);
+CFX_ByteString PDF_NameEncode(const CFX_ByteString& orig);
+CFX_ByteString PDF_EncodeString(const CFX_ByteString& src,
+                                FX_BOOL bHex = FALSE);
+CFX_WideString PDF_DecodeText(const uint8_t* pData, uint32_t size);
+CFX_WideString PDF_DecodeText(const CFX_ByteString& bstr);
+CFX_ByteString PDF_EncodeText(const FX_WCHAR* pString, int len = -1);
+CFX_ByteString PDF_EncodeText(const CFX_WideString& str);
+
+bool FlateEncode(const uint8_t* src_buf,
+                 uint32_t src_size,
+                 uint8_t** dest_buf,
+                 uint32_t* dest_size);
+
+// This used to have more parameters like the predictor and bpc, but there was
+// only one caller, so the interface has been simplified, the values are hard
+// coded, and dead code has been removed.
+bool PngEncode(const uint8_t* src_buf,
+               uint32_t src_size,
+               uint8_t** dest_buf,
+               uint32_t* dest_size);
+
+uint32_t FlateDecode(const uint8_t* src_buf,
+                     uint32_t src_size,
+                     uint8_t*& dest_buf,
+                     uint32_t& dest_size);
+uint32_t RunLengthDecode(const uint8_t* src_buf,
+                         uint32_t src_size,
+                         uint8_t*& dest_buf,
+                         uint32_t& dest_size);
+
+// Public for testing.
+uint32_t A85Decode(const uint8_t* src_buf,
+                   uint32_t src_size,
+                   uint8_t*& dest_buf,
+                   uint32_t& dest_size);
+// Public for testing.
+uint32_t HexDecode(const uint8_t* src_buf,
+                   uint32_t src_size,
+                   uint8_t*& dest_buf,
+                   uint32_t& dest_size);
+// Public for testing.
+uint32_t FPDFAPI_FlateOrLZWDecode(FX_BOOL bLZW,
+                                  const uint8_t* src_buf,
+                                  uint32_t src_size,
+                                  CPDF_Dictionary* pParams,
+                                  uint32_t estimated_size,
+                                  uint8_t*& dest_buf,
+                                  uint32_t& dest_size);
+FX_BOOL PDF_DataDecode(const uint8_t* src_buf,
+                       uint32_t src_size,
+                       const CPDF_Dictionary* pDict,
+                       uint8_t*& dest_buf,
+                       uint32_t& dest_size,
+                       CFX_ByteString& ImageEncoding,
+                       CPDF_Dictionary*& pImageParms,
+                       uint32_t estimated_size,
+                       FX_BOOL bImageAcc);
+
+#endif  // CORE_FPDFAPI_PARSER_FPDF_PARSER_DECODE_H_
diff --git a/core/fpdfapi/parser/fpdf_parser_decode_embeddertest.cpp b/core/fpdfapi/parser/fpdf_parser_decode_embeddertest.cpp
new file mode 100644
index 0000000000..639dcbf44c
--- /dev/null
+++ b/core/fpdfapi/parser/fpdf_parser_decode_embeddertest.cpp
@@ -0,0 +1,117 @@
+// Copyright 2015 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "core/fpdfapi/parser/fpdf_parser_decode.h"
+
+#include <cstring>
+#include <string>
+
+#include "core/fxcrt/fx_basic.h"
+#include "testing/embedder_test.h"
+#include "testing/fx_string_testhelpers.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "testing/test_support.h"
+
+class FPDFParserDecodeEmbeddertest : public EmbedderTest {};
+
+// NOTE: python's zlib.compress() and zlib.decompress() may be useful for
+// external validation of the FlateEncode/FlateDecode test cases.
+
+TEST_F(FPDFParserDecodeEmbeddertest, FlateEncode) {
+  pdfium::StrFuncTestData flate_encode_cases[] = {
+      STR_IN_OUT_CASE("", "\x78\x9c\x03\x00\x00\x00\x00\x01"),
+      STR_IN_OUT_CASE(" ", "\x78\x9c\x53\x00\x00\x00\x21\x00\x21"),
+      STR_IN_OUT_CASE("123", "\x78\x9c\x33\x34\x32\x06\x00\01\x2d\x00\x97"),
+      STR_IN_OUT_CASE("\x00\xff", "\x78\x9c\x63\xf8\x0f\x00\x01\x01\x01\x00"),
+      STR_IN_OUT_CASE(
+          "1 0 0 -1 29 763 cm\n0 0 555 735 re\nW n\nq\n0 0 555 734.394 re\n"
+          "W n\nq\n0.8009 0 0 0.8009 0 0 cm\n1 1 1 RG 1 1 1 rg\n/G0 gs\n"
+          "0 0 693 917 re\nf\nQ\nQ\n",
+          "\x78\x9c\x33\x54\x30\x00\x42\x5d\x43\x05\x23\x4b\x05\x73\x33\x63"
+          "\x85\xe4\x5c\x2e\x90\x80\xa9\xa9\xa9\x82\xb9\xb1\xa9\x42\x51\x2a"
+          "\x57\xb8\x42\x1e\x57\x21\x92\xa0\x89\x9e\xb1\xa5\x09\x92\x84\x9e"
+          "\x85\x81\x81\x25\xd8\x14\x24\x26\xd0\x18\x43\x05\x10\x0c\x72\x57"
+          "\x80\x30\x8a\xd2\xb9\xf4\xdd\x0d\x14\xd2\x8b\xc1\x46\x99\x59\x1a"
+          "\x2b\x58\x1a\x9a\x83\x8c\x49\xe3\x0a\x04\x42\x00\x37\x4c\x1b\x42"),
+  };
+
+  for (size_t i = 0; i < FX_ArraySize(flate_encode_cases); ++i) {
+    const pdfium::StrFuncTestData& data = flate_encode_cases[i];
+    unsigned char* buf = nullptr;
+    unsigned int buf_size;
+    EXPECT_TRUE(FlateEncode(data.input, data.input_size, &buf, &buf_size));
+    ASSERT_TRUE(buf);
+    EXPECT_EQ(std::string((const char*)data.expected, data.expected_size),
+              std::string((const char*)buf, buf_size))
+        << " for case " << i;
+    FX_Free(buf);
+  }
+}
+
+TEST_F(FPDFParserDecodeEmbeddertest, FlateDecode) {
+  pdfium::DecodeTestData flate_decode_cases[] = {
+      STR_IN_OUT_CASE("", "", 0),
+      STR_IN_OUT_CASE("preposterous nonsense", "", 2),
+      STR_IN_OUT_CASE("\x78\x9c\x03\x00\x00\x00\x00\x01", "", 8),
+      STR_IN_OUT_CASE("\x78\x9c\x53\x00\x00\x00\x21\x00\x21", " ", 9),
+      STR_IN_OUT_CASE("\x78\x9c\x33\x34\x32\x06\x00\01\x2d\x00\x97", "123", 11),
+      STR_IN_OUT_CASE("\x78\x9c\x63\xf8\x0f\x00\x01\x01\x01\x00", "\x00\xff",
+                      10),
+      STR_IN_OUT_CASE(
+          "\x78\x9c\x33\x54\x30\x00\x42\x5d\x43\x05\x23\x4b\x05\x73\x33\x63"
+          "\x85\xe4\x5c\x2e\x90\x80\xa9\xa9\xa9\x82\xb9\xb1\xa9\x42\x51\x2a"
+          "\x57\xb8\x42\x1e\x57\x21\x92\xa0\x89\x9e\xb1\xa5\x09\x92\x84\x9e"
+          "\x85\x81\x81\x25\xd8\x14\x24\x26\xd0\x18\x43\x05\x10\x0c\x72\x57"
+          "\x80\x30\x8a\xd2\xb9\xf4\xdd\x0d\x14\xd2\x8b\xc1\x46\x99\x59\x1a"
+          "\x2b\x58\x1a\x9a\x83\x8c\x49\xe3\x0a\x04\x42\x00\x37\x4c\x1b\x42",
+          "1 0 0 -1 29 763 cm\n0 0 555 735 re\nW n\nq\n0 0 555 734.394 re\n"
+          "W n\nq\n0.8009 0 0 0.8009 0 0 cm\n1 1 1 RG 1 1 1 rg\n/G0 gs\n"
+          "0 0 693 917 re\nf\nQ\nQ\n",
+          96),
+  };
+
+  for (size_t i = 0; i < FX_ArraySize(flate_decode_cases); ++i) {
+    const pdfium::DecodeTestData& data = flate_decode_cases[i];
+    unsigned char* result = nullptr;
+    unsigned int result_size;
+    EXPECT_EQ(data.processed_size,
+              FlateDecode(data.input, data.input_size, result, result_size))
+        << " for case " << i;
+    ASSERT_TRUE(result);
+    EXPECT_EQ(std::string((const char*)data.expected, data.expected_size),
+              std::string((const char*)result, result_size))
+        << " for case " << i;
+    FX_Free(result);
+  }
+}
+
+TEST_F(FPDFParserDecodeEmbeddertest, Bug_552046) {
+  // Tests specifying multiple image filters for a stream. Should not cause a
+  // crash when rendered.
+  EXPECT_TRUE(OpenDocument("bug_552046.pdf"));
+  FPDF_PAGE page = LoadPage(0);
+  FPDF_BITMAP bitmap = RenderPage(page);
+  FPDFBitmap_Destroy(bitmap);
+  UnloadPage(page);
+}
+
+TEST_F(FPDFParserDecodeEmbeddertest, Bug_555784) {
+  // Tests bad input to the run length decoder that caused a heap overflow.
+  // Should not cause a crash when rendered.
+  EXPECT_TRUE(OpenDocument("bug_555784.pdf"));
+  FPDF_PAGE page = LoadPage(0);
+  FPDF_BITMAP bitmap = RenderPage(page);
+  FPDFBitmap_Destroy(bitmap);
+  UnloadPage(page);
+}
+
+TEST_F(FPDFParserDecodeEmbeddertest, Bug_455199) {
+  // Tests object numbers with a value > 01000000.
+  // Should open successfully.
+  EXPECT_TRUE(OpenDocument("bug_455199.pdf"));
+  FPDF_PAGE page = LoadPage(0);
+  FPDF_BITMAP bitmap = RenderPage(page);
+  FPDFBitmap_Destroy(bitmap);
+  UnloadPage(page);
+}
diff --git a/core/fpdfapi/parser/fpdf_parser_decode_unittest.cpp b/core/fpdfapi/parser/fpdf_parser_decode_unittest.cpp
new file mode 100644
index 0000000000..83860f9146
--- /dev/null
+++ b/core/fpdfapi/parser/fpdf_parser_decode_unittest.cpp
@@ -0,0 +1,78 @@
+// Copyright 2015 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "core/fpdfapi/parser/fpdf_parser_decode.h"
+
+#include "testing/gtest/include/gtest/gtest.h"
+#include "testing/test_support.h"
+
+TEST(fpdf_parser_decode, A85Decode) {
+  pdfium::DecodeTestData test_data[] = {
+      // Empty src string.
+      STR_IN_OUT_CASE("", "", 0),
+      // Empty content in src string.
+      STR_IN_OUT_CASE("~>", "", 0),
+      // Regular conversion.
+      STR_IN_OUT_CASE("FCfN8~>", "test", 7),
+      // End at the ending mark.
+      STR_IN_OUT_CASE("FCfN8~>FCfN8", "test", 7),
+      // Skip whitespaces.
+      STR_IN_OUT_CASE("\t F C\r\n \tf N 8 ~>", "test", 17),
+      // No ending mark.
+      STR_IN_OUT_CASE("@3B0)DJj_BF*)>@Gp#-s", "a funny story :)", 20),
+      // Non-multiple length.
+      STR_IN_OUT_CASE("12A", "2k", 3),
+      // Stop at unknown characters.
+      STR_IN_OUT_CASE("FCfN8FCfN8vw", "testtest", 11),
+  };
+  for (size_t i = 0; i < FX_ArraySize(test_data); ++i) {
+    pdfium::DecodeTestData* ptr = &test_data[i];
+    uint8_t* result = nullptr;
+    uint32_t result_size = 0;
+    EXPECT_EQ(ptr->processed_size,
+              A85Decode(ptr->input, ptr->input_size, result, result_size))
+        << "for case " << i;
+    ASSERT_EQ(ptr->expected_size, result_size);
+    for (size_t j = 0; j < result_size; ++j) {
+      EXPECT_EQ(ptr->expected[j], result[j]) << "for case " << i << " char "
+                                             << j;
+    }
+    FX_Free(result);
+  }
+}
+
+TEST(fpdf_parser_decode, HexDecode) {
+  pdfium::DecodeTestData test_data[] = {
+      // Empty src string.
+      STR_IN_OUT_CASE("", "", 0),
+      // Empty content in src string.
+      STR_IN_OUT_CASE(">", "", 1),
+      // Only whitespaces in src string.
+      STR_IN_OUT_CASE("\t   \r\n>", "", 7),
+      // Regular conversion.
+      STR_IN_OUT_CASE("12Ac>zzz", "\x12\xac", 5),
+      // Skip whitespaces.
+      STR_IN_OUT_CASE("12 Ac\t02\r\nBF>zzz>", "\x12\xac\x02\xbf", 13),
+      // Non-multiple length.
+      STR_IN_OUT_CASE("12A>zzz", "\x12\xa0", 4),
+      // Skips unknown characters.
+      STR_IN_OUT_CASE("12tk  \tAc>zzz", "\x12\xac", 10),
+      // No ending mark.
+      STR_IN_OUT_CASE("12AcED3c3456", "\x12\xac\xed\x3c\x34\x56", 12),
+  };
+  for (size_t i = 0; i < FX_ArraySize(test_data); ++i) {
+    pdfium::DecodeTestData* ptr = &test_data[i];
+    uint8_t* result = nullptr;
+    uint32_t result_size = 0;
+    EXPECT_EQ(ptr->processed_size,
+              HexDecode(ptr->input, ptr->input_size, result, result_size))
+        << "for case " << i;
+    ASSERT_EQ(ptr->expected_size, result_size);
+    for (size_t j = 0; j < result_size; ++j) {
+      EXPECT_EQ(ptr->expected[j], result[j]) << "for case " << i << " char "
+                                             << j;
+    }
+    FX_Free(result);
+  }
+}
diff --git a/core/fpdfapi/parser/fpdf_parser_utility.cpp b/core/fpdfapi/parser/fpdf_parser_utility.cpp
new file mode 100644
index 0000000000..10fac7fa1c
--- /dev/null
+++ b/core/fpdfapi/parser/fpdf_parser_utility.cpp
@@ -0,0 +1,221 @@
+// Copyright 2014 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#include "core/fpdfapi/parser/fpdf_parser_utility.h"
+
+#include "core/fpdfapi/parser/cpdf_array.h"
+#include "core/fpdfapi/parser/cpdf_dictionary.h"
+#include "core/fpdfapi/parser/cpdf_number.h"
+#include "core/fpdfapi/parser/cpdf_reference.h"
+#include "core/fpdfapi/parser/cpdf_stream.h"
+#include "core/fpdfapi/parser/cpdf_stream_acc.h"
+#include "core/fpdfapi/parser/cpdf_string.h"
+#include "core/fpdfapi/parser/fpdf_parser_decode.h"
+#include "core/fxcrt/fx_ext.h"
+
+// Indexed by 8-bit character code, contains either:
+//   'W' - for whitespace: NUL, TAB, CR, LF, FF, SPACE, 0x80, 0xff
+//   'N' - for numeric: 0123456789+-.
+//   'D' - for delimiter: %()/<>[]{}
+//   'R' - otherwise.
+const char PDF_CharType[256] = {
+    // NUL  SOH  STX  ETX  EOT  ENQ  ACK  BEL  BS   HT   LF   VT   FF   CR   SO
+    // SI
+    'W', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'W', 'W', 'R', 'W', 'W', 'R',
+    'R',
+
+    // DLE  DC1  DC2  DC3  DC4  NAK  SYN  ETB  CAN  EM   SUB  ESC  FS   GS   RS
+    // US
+    'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R',
+    'R',
+
+    // SP    !    "    #    $    %    &    ´    (    )    *    +    ,    -    .
+    // /
+    'W', 'R', 'R', 'R', 'R', 'D', 'R', 'R', 'D', 'D', 'R', 'N', 'R', 'N', 'N',
+    'D',
+
+    // 0    1    2    3    4    5    6    7    8    9    :    ;    <    =    > ?
+    'N', 'N', 'N', 'N', 'N', 'N', 'N', 'N', 'N', 'N', 'R', 'R', 'D', 'R', 'D',
+    'R',
+
+    // @    A    B    C    D    E    F    G    H    I    J    K    L    M    N O
+    'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R',
+    'R',
+
+    // P    Q    R    S    T    U    V    W    X    Y    Z    [    \    ]    ^ _
+    'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'D', 'R', 'D', 'R',
+    'R',
+
+    // `    a    b    c    d    e    f    g    h    i    j    k    l    m    n o
+    'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R',
+    'R',
+
+    // p    q    r    s    t    u    v    w    x    y    z    {    |    }    ~
+    // DEL
+    'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'D', 'R', 'D', 'R',
+    'R',
+
+    'W', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R',
+    'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R',
+    'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R',
+    'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R',
+    'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R',
+    'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R',
+    'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R',
+    'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R',
+    'R', 'R', 'R', 'R', 'R', 'R', 'R', 'W'};
+
+int32_t GetHeaderOffset(IFX_FileRead* pFile) {
+  const size_t kBufSize = 4;
+  uint8_t buf[kBufSize];
+  for (int32_t offset = 0; offset <= 1024; ++offset) {
+    if (!pFile->ReadBlock(buf, offset, kBufSize))
+      return -1;
+
+    if (memcmp(buf, "%PDF", 4) == 0)
+      return offset;
+  }
+  return -1;
+}
+
+int32_t GetDirectInteger(CPDF_Dictionary* pDict, const CFX_ByteString& key) {
+  CPDF_Number* pObj = ToNumber(pDict->GetObjectFor(key));
+  return pObj ? pObj->GetInteger() : 0;
+}
+
+CFX_ByteString PDF_NameDecode(const CFX_ByteStringC& bstr) {
+  if (bstr.Find('#') == -1)
+    return CFX_ByteString(bstr);
+
+  int size = bstr.GetLength();
+  CFX_ByteString result;
+  FX_CHAR* pDestStart = result.GetBuffer(size);
+  FX_CHAR* pDest = pDestStart;
+  for (int i = 0; i < size; i++) {
+    if (bstr[i] == '#' && i < size - 2) {
+      *pDest++ =
+          FXSYS_toHexDigit(bstr[i + 1]) * 16 + FXSYS_toHexDigit(bstr[i + 2]);
+      i += 2;
+    } else {
+      *pDest++ = bstr[i];
+    }
+  }
+  result.ReleaseBuffer((FX_STRSIZE)(pDest - pDestStart));
+  return result;
+}
+
+CFX_ByteString PDF_NameDecode(const CFX_ByteString& orig) {
+  if (orig.Find('#') == -1)
+    return orig;
+  return PDF_NameDecode(orig.AsStringC());
+}
+
+CFX_ByteString PDF_NameEncode(const CFX_ByteString& orig) {
+  uint8_t* src_buf = (uint8_t*)orig.c_str();
+  int src_len = orig.GetLength();
+  int dest_len = 0;
+  int i;
+  for (i = 0; i < src_len; i++) {
+    uint8_t ch = src_buf[i];
+    if (ch >= 0x80 || PDFCharIsWhitespace(ch) || ch == '#' ||
+        PDFCharIsDelimiter(ch)) {
+      dest_len += 3;
+    } else {
+      dest_len++;
+    }
+  }
+  if (dest_len == src_len)
+    return orig;
+
+  CFX_ByteString res;
+  FX_CHAR* dest_buf = res.GetBuffer(dest_len);
+  dest_len = 0;
+  for (i = 0; i < src_len; i++) {
+    uint8_t ch = src_buf[i];
+    if (ch >= 0x80 || PDFCharIsWhitespace(ch) || ch == '#' ||
+        PDFCharIsDelimiter(ch)) {
+      dest_buf[dest_len++] = '#';
+      dest_buf[dest_len++] = "0123456789ABCDEF"[ch / 16];
+      dest_buf[dest_len++] = "0123456789ABCDEF"[ch % 16];
+    } else {
+      dest_buf[dest_len++] = ch;
+    }
+  }
+  dest_buf[dest_len] = 0;
+  res.ReleaseBuffer();
+  return res;
+}
+
+CFX_ByteTextBuf& operator<<(CFX_ByteTextBuf& buf, const CPDF_Object* pObj) {
+  if (!pObj) {
+    buf << " null";
+    return buf;
+  }
+  switch (pObj->GetType()) {
+    case CPDF_Object::NULLOBJ:
+      buf << " null";
+      break;
+    case CPDF_Object::BOOLEAN:
+    case CPDF_Object::NUMBER:
+      buf << " " << pObj->GetString();
+      break;
+    case CPDF_Object::STRING:
+      buf << PDF_EncodeString(pObj->GetString(), pObj->AsString()->IsHex());
+      break;
+    case CPDF_Object::NAME: {
+      CFX_ByteString str = pObj->GetString();
+      buf << "/" << PDF_NameEncode(str);
+      break;
+    }
+    case CPDF_Object::REFERENCE: {
+      buf << " " << pObj->AsReference()->GetRefObjNum() << " 0 R ";
+      break;
+    }
+    case CPDF_Object::ARRAY: {
+      const CPDF_Array* p = pObj->AsArray();
+      buf << "[";
+      for (size_t i = 0; i < p->GetCount(); i++) {
+        CPDF_Object* pElement = p->GetObjectAt(i);
+        if (pElement && pElement->GetObjNum()) {
+          buf << " " << pElement->GetObjNum() << " 0 R";
+        } else {
+          buf << pElement;
+        }
+      }
+      buf << "]";
+      break;
+    }
+    case CPDF_Object::DICTIONARY: {
+      const CPDF_Dictionary* p = pObj->AsDictionary();
+      buf << "<<";
+      for (const auto& it : *p) {
+        const CFX_ByteString& key = it.first;
+        CPDF_Object* pValue = it.second;
+        buf << "/" << PDF_NameEncode(key);
+        if (pValue && pValue->GetObjNum()) {
+          buf << " " << pValue->GetObjNum() << " 0 R ";
+        } else {
+          buf << pValue;
+        }
+      }
+      buf << ">>";
+      break;
+    }
+    case CPDF_Object::STREAM: {
+      const CPDF_Stream* p = pObj->AsStream();
+      buf << p->GetDict() << "stream\r\n";
+      CPDF_StreamAcc acc;
+      acc.LoadAllData(p, TRUE);
+      buf.AppendBlock(acc.GetData(), acc.GetSize());
+      buf << "\r\nendstream";
+      break;
+    }
+    default:
+      ASSERT(FALSE);
+      break;
+  }
+  return buf;
+}
diff --git a/core/fpdfapi/parser/fpdf_parser_utility.h b/core/fpdfapi/parser/fpdf_parser_utility.h
new file mode 100644
index 0000000000..4c0187ed4a
--- /dev/null
+++ b/core/fpdfapi/parser/fpdf_parser_utility.h
@@ -0,0 +1,39 @@
+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#ifndef CORE_FPDFAPI_PARSER_FPDF_PARSER_UTILITY_H_
+#define CORE_FPDFAPI_PARSER_FPDF_PARSER_UTILITY_H_
+
+#include "core/fxcrt/fx_string.h"
+#include "core/fxcrt/fx_system.h"
+
+class IFX_FileRead;
+class CPDF_Dictionary;
+
+// Use the accessors below instead of directly accessing PDF_CharType.
+extern const char PDF_CharType[256];
+
+inline bool PDFCharIsWhitespace(uint8_t c) {
+  return PDF_CharType[c] == 'W';
+}
+inline bool PDFCharIsNumeric(uint8_t c) {
+  return PDF_CharType[c] == 'N';
+}
+inline bool PDFCharIsDelimiter(uint8_t c) {
+  return PDF_CharType[c] == 'D';
+}
+inline bool PDFCharIsOther(uint8_t c) {
+  return PDF_CharType[c] == 'R';
+}
+
+inline bool PDFCharIsLineEnding(uint8_t c) {
+  return c == '\r' || c == '\n';
+}
+
+int32_t GetHeaderOffset(IFX_FileRead* pFile);
+int32_t GetDirectInteger(CPDF_Dictionary* pDict, const CFX_ByteString& key);
+
+#endif  // CORE_FPDFAPI_PARSER_FPDF_PARSER_UTILITY_H_