Rework of loading of CPDF_Document.

Improve CPDF_Document interface.
Fix relationship between CPDF_Document and CPDF_Parser.
This CL changes CPDF_Document to internally create the CPDF_Parser
and removes the need for the CPDF_Parser to know about the CPDF_Document.


Change-Id: Iec7aef19575c90f30b9a6c919dfd4f4417e4caf2
Reviewed-on: https://pdfium-review.googlesource.com/35630
Commit-Queue: Art Snake <art-snake@yandex-team.ru>
Reviewed-by: dsinclair <dsinclair@chromium.org>

7 files changed, 137 insertions, 84 deletions

diff --git a/core/fpdfapi/parser/cpdf_data_avail.cpp b/core/fpdfapi/parser/cpdf_data_avail.cpp
index acc01c65ed..3b39e3f54b 100644
--- a/core/fpdfapi/parser/cpdf_data_avail.cpp
+++ b/core/fpdfapi/parser/cpdf_data_avail.cpp
@@ -214,7 +214,7 @@ std::unique_ptr<CPDF_Object> CPDF_DataAvail::GetObject(uint32_t objnum,
   std::unique_ptr<CPDF_Object> pRet;
   if (pParser) {
     const CPDF_ReadValidator::Session read_session(GetValidator().Get());
-    pRet = pParser->ParseIndirectObject(nullptr, objnum);
+    pRet = pParser->ParseIndirectObject(objnum);
     if (GetValidator()->has_read_problems())
       return nullptr;
   }
@@ -233,7 +233,7 @@ bool CPDF_DataAvail::CheckInfo() {
   }
 
   const CPDF_ReadValidator::Session read_session(GetValidator().Get());
-  m_parser.ParseIndirectObject(nullptr, dwInfoObjNum);
+  m_parser.ParseIndirectObject(dwInfoObjNum);
   if (GetValidator()->has_read_problems())
     return false;
 
@@ -249,7 +249,7 @@ bool CPDF_DataAvail::CheckRoot() {
   }
 
   const CPDF_ReadValidator::Session read_session(GetValidator().Get());
-  m_pRoot = ToDictionary(m_parser.ParseIndirectObject(nullptr, dwRootObjNum));
+  m_pRoot = ToDictionary(m_parser.ParseIndirectObject(dwRootObjNum));
   if (GetValidator()->has_read_problems())
     return false;
 
@@ -1011,11 +1011,11 @@ CPDF_DataAvail::ParseDocument(const char* password) {
   }
   auto parser = pdfium::MakeUnique<CPDF_Parser>();
   parser->SetPassword(password);
-  auto document = pdfium::MakeUnique<CPDF_Document>(std::move(parser));
+  auto document = pdfium::MakeUnique<CPDF_Document>();
 
   CPDF_ReadValidator::Session read_session(GetValidator().Get());
-  CPDF_Parser::Error error = document->GetParser()->StartLinearizedParse(
-      GetValidator(), document.get());
+  CPDF_Parser::Error error =
+      document->LoadLinearizedDoc(GetValidator(), password);
 
   // Additional check, that all ok.
   if (GetValidator()->has_read_problems()) {
diff --git a/core/fpdfapi/parser/cpdf_data_avail.h b/core/fpdfapi/parser/cpdf_data_avail.h
index 8872bb103f..b6396bf82a 100644
--- a/core/fpdfapi/parser/cpdf_data_avail.h
+++ b/core/fpdfapi/parser/cpdf_data_avail.h
@@ -19,6 +19,7 @@
 
 class CPDF_CrossRefAvail;
 class CPDF_Dictionary;
+class CPDF_Document;
 class CPDF_HintTables;
 class CPDF_IndirectObjectHolder;
 class CPDF_LinearizedHeader;
diff --git a/core/fpdfapi/parser/cpdf_document.cpp b/core/fpdfapi/parser/cpdf_document.cpp
index 8f727ed14a..91c6b9c6f9 100644
--- a/core/fpdfapi/parser/cpdf_document.cpp
+++ b/core/fpdfapi/parser/cpdf_document.cpp
@@ -22,6 +22,7 @@
 #include "core/fpdfapi/parser/cpdf_name.h"
 #include "core/fpdfapi/parser/cpdf_number.h"
 #include "core/fpdfapi/parser/cpdf_parser.h"
+#include "core/fpdfapi/parser/cpdf_read_validator.h"
 #include "core/fpdfapi/parser/cpdf_reference.h"
 #include "core/fpdfapi/parser/cpdf_stream.h"
 #include "core/fpdfapi/parser/cpdf_string.h"
@@ -185,17 +186,13 @@ std::unique_ptr<CPDF_Dictionary> CalculateFontDesc(
 
 }  // namespace
 
-CPDF_Document::CPDF_Document(std::unique_ptr<CPDF_Parser> pParser)
-    : CPDF_IndirectObjectHolder(),
-      m_pParser(std::move(pParser)),
+CPDF_Document::CPDF_Document()
+    : ParsedObjectsHolder(),
       m_pRootDict(nullptr),
       m_iNextPageToTraverse(0),
       m_bReachedMaxPageLevel(false),
       m_pDocPage(pdfium::MakeUnique<CPDF_DocPageData>(this)),
-      m_pDocRender(pdfium::MakeUnique<CPDF_DocRenderData>(this)) {
-  if (pParser)
-    SetLastObjNum(m_pParser->GetLastObjNum());
-}
+      m_pDocRender(pdfium::MakeUnique<CPDF_DocRenderData>(this)) {}
 
 CPDF_Document::~CPDF_Document() {
   CPDF_ModuleMgr::Get()->GetPageModule()->ClearStockFont(this);
@@ -203,7 +200,7 @@ CPDF_Document::~CPDF_Document() {
 
 std::unique_ptr<CPDF_Object> CPDF_Document::ParseIndirectObject(
     uint32_t objnum) {
-  return m_pParser ? m_pParser->ParseIndirectObject(this, objnum) : nullptr;
+  return m_pParser ? m_pParser->ParseIndirectObject(objnum) : nullptr;
 }
 
 void CPDF_Document::LoadDocInternal() {
@@ -218,9 +215,28 @@ void CPDF_Document::LoadDocInternal() {
     return;
 }
 
-void CPDF_Document::LoadDoc() {
+bool CPDF_Document::TryInit() {
   LoadDocInternal();
   LoadPages();
+  return GetRoot() && (GetPageCount() > 0);
+}
+
+CPDF_Parser::Error CPDF_Document::LoadDoc(
+    const RetainPtr<IFX_SeekableReadStream>& pFileAccess,
+    const char* password) {
+  if (!m_pParser)
+    SetParser(pdfium::MakeUnique<CPDF_Parser>(this));
+
+  return m_pParser->StartParse(pFileAccess, password);
+}
+
+CPDF_Parser::Error CPDF_Document::LoadLinearizedDoc(
+    const RetainPtr<CPDF_ReadValidator>& validator,
+    const char* password) {
+  if (!m_pParser)
+    SetParser(pdfium::MakeUnique<CPDF_Parser>(this));
+
+  return m_pParser->StartLinearizedParse(validator, password);
 }
 
 void CPDF_Document::LoadPages() {
@@ -309,6 +325,11 @@ void CPDF_Document::ResetTraversal() {
   m_pTreeTraversal.clear();
 }
 
+void CPDF_Document::SetParser(std::unique_ptr<CPDF_Parser> pParser) {
+  DCHECK(!m_pParser);
+  m_pParser = std::move(pParser);
+}
+
 const CPDF_Dictionary* CPDF_Document::GetPagesDict() const {
   const CPDF_Dictionary* pRoot = GetRoot();
   return pRoot ? pRoot->GetDictFor("Pages") : nullptr;
diff --git a/core/fpdfapi/parser/cpdf_document.h b/core/fpdfapi/parser/cpdf_document.h
index 8d0aa08009..328f09b6ef 100644
--- a/core/fpdfapi/parser/cpdf_document.h
+++ b/core/fpdfapi/parser/cpdf_document.h
@@ -15,9 +15,10 @@
 
 #include "core/fpdfapi/page/cpdf_image.h"
 #include "core/fpdfapi/page/cpdf_page.h"
-#include "core/fpdfapi/parser/cpdf_indirect_object_holder.h"
 #include "core/fpdfapi/parser/cpdf_object.h"
+#include "core/fpdfapi/parser/cpdf_parser.h"
 #include "core/fpdfdoc/cpdf_linklist.h"
+#include "core/fxcrt/retain_ptr.h"
 
 class CFX_Font;
 class CFX_Matrix;
@@ -30,7 +31,9 @@ class CPDF_IccProfile;
 class CPDF_LinearizedHeader;
 class CPDF_Parser;
 class CPDF_Pattern;
+class CPDF_ReadValidator;
 class CPDF_StreamAcc;
+class IFX_SeekableReadStream;
 class JBig2_DocumentContext;
 
 #define FPDFPERM_MODIFY 0x0008
@@ -38,7 +41,7 @@ class JBig2_DocumentContext;
 #define FPDFPERM_FILL_FORM 0x0100
 #define FPDFPERM_EXTRACT_ACCESS 0x0200
 
-class CPDF_Document : public CPDF_IndirectObjectHolder {
+class CPDF_Document : public CPDF_Parser::ParsedObjectsHolder {
  public:
   // Type from which the XFA extension can subclass itself.
   class Extension {
@@ -52,7 +55,7 @@ class CPDF_Document : public CPDF_IndirectObjectHolder {
 
   static const int kPageMaxNum = 0xFFFFF;
 
-  explicit CPDF_Document(std::unique_ptr<CPDF_Parser> pParser);
+  CPDF_Document();
   ~CPDF_Document() override;
 
   Extension* GetExtension() const { return m_pExtension.get(); }
@@ -96,7 +99,16 @@ class CPDF_Document : public CPDF_IndirectObjectHolder {
   RetainPtr<CPDF_StreamAcc> LoadFontFile(const CPDF_Stream* pStream);
   RetainPtr<CPDF_IccProfile> LoadIccProfile(const CPDF_Stream* pStream);
 
-  void LoadDoc();
+  //  CPDF_Parser::ParsedObjectsHolder overrides:
+  bool TryInit() override;
+
+  CPDF_Parser::Error LoadDoc(
+      const RetainPtr<IFX_SeekableReadStream>& pFileAccess,
+      const char* password);
+  CPDF_Parser::Error LoadLinearizedDoc(
+      const RetainPtr<CPDF_ReadValidator>& validator,
+      const char* password);
+
   void LoadPages();
 
   void CreateNewDoc();
@@ -144,6 +156,7 @@ class CPDF_Document : public CPDF_IndirectObjectHolder {
                            std::set<CPDF_Dictionary*>* pVisited);
   bool InsertNewPage(int iPage, CPDF_Dictionary* pPageDict);
   void ResetTraversal();
+  void SetParser(std::unique_ptr<CPDF_Parser> pParser);
 
   std::unique_ptr<CPDF_Parser> m_pParser;
   UnownedPtr<CPDF_Dictionary> m_pRootDict;
diff --git a/core/fpdfapi/parser/cpdf_document_unittest.cpp b/core/fpdfapi/parser/cpdf_document_unittest.cpp
index 522aa65fc9..c64da6382a 100644
--- a/core/fpdfapi/parser/cpdf_document_unittest.cpp
+++ b/core/fpdfapi/parser/cpdf_document_unittest.cpp
@@ -49,7 +49,7 @@ std::unique_ptr<CPDF_Dictionary> CreateNumberedPage(size_t number) {
 
 class CPDF_TestDocumentForPages : public CPDF_Document {
  public:
-  CPDF_TestDocumentForPages() : CPDF_Document(nullptr) {
+  CPDF_TestDocumentForPages() : CPDF_Document() {
     // Set up test
     auto zeroToTwo = pdfium::MakeUnique<CPDF_Array>();
     zeroToTwo->AddNew<CPDF_Reference>(
@@ -101,7 +101,7 @@ class CPDF_TestDocumentForPages : public CPDF_Document {
 
 class CPDF_TestDocumentWithPageWithoutPageNum : public CPDF_Document {
  public:
-  CPDF_TestDocumentWithPageWithoutPageNum() : CPDF_Document(nullptr) {
+  CPDF_TestDocumentWithPageWithoutPageNum() : CPDF_Document() {
     // Set up test
     auto allPages = pdfium::MakeUnique<CPDF_Array>();
     allPages->AddNew<CPDF_Reference>(
@@ -132,7 +132,7 @@ class TestLinearized : public CPDF_LinearizedHeader {
 
 class CPDF_TestDocPagesWithoutKids : public CPDF_Document {
  public:
-  CPDF_TestDocPagesWithoutKids() : CPDF_Document(nullptr) {
+  CPDF_TestDocPagesWithoutKids() : CPDF_Document() {
     CPDF_Dictionary* pagesDict = NewIndirect<CPDF_Dictionary>();
     pagesDict->SetNewFor<CPDF_Name>("Type", "Pages");
     pagesDict->SetNewFor<CPDF_Number>("Count", 3);
@@ -143,6 +143,11 @@ class CPDF_TestDocPagesWithoutKids : public CPDF_Document {
   }
 };
 
+class CPDF_TestDocumentAllowSetParser : public CPDF_Document {
+ public:
+  using CPDF_Document::SetParser;
+};
+
 }  // namespace
 
 class cpdf_document_test : public testing::Test {
@@ -222,8 +227,9 @@ TEST_F(cpdf_document_test, UseCachedPageObjNumIfHaveNotPagesDict) {
   auto linearized = pdfium::MakeUnique<TestLinearized>(dict.get());
   auto parser = pdfium::MakeUnique<CPDF_Parser>();
   parser->SetLinearizedHeader(std::move(linearized));
-  CPDF_Document document(std::move(parser));
-  document.LoadDoc();
+  CPDF_TestDocumentAllowSetParser document;
+  document.SetParser(std::move(parser));
+  document.LoadPages();
   ASSERT_EQ(page_count, document.GetPageCount());
   CPDF_Object* page_stub = document.NewIndirect<CPDF_Dictionary>();
   const uint32_t obj_num = page_stub->GetObjNum();
diff --git a/core/fpdfapi/parser/cpdf_parser.cpp b/core/fpdfapi/parser/cpdf_parser.cpp
index c7a3fe16c8..3986f3684f 100644
--- a/core/fpdfapi/parser/cpdf_parser.cpp
+++ b/core/fpdfapi/parser/cpdf_parser.cpp
@@ -47,6 +47,13 @@ uint32_t GetVarInt(const uint8_t* p, int32_t n) {
   return result;
 }
 
+class ObjectsHolderStub : public CPDF_Parser::ParsedObjectsHolder {
+ public:
+  ObjectsHolderStub() = default;
+  ~ObjectsHolderStub() override = default;
+  bool TryInit() override { return true; }
+};
+
 }  // namespace
 
 class CPDF_Parser::TrailerData {
@@ -117,12 +124,20 @@ class CPDF_Parser::TrailerData {
   uint32_t last_root_obj_num_ = CPDF_Object::kInvalidObjNum;
 };
 
-CPDF_Parser::CPDF_Parser()
+CPDF_Parser::CPDF_Parser(ParsedObjectsHolder* holder)
     : m_pSyntax(pdfium::MakeUnique<CPDF_SyntaxParser>()),
+      m_pObjectsHolder(holder),
       m_bHasParsed(false),
       m_bXRefStream(false),
       m_FileVersion(0),
-      m_TrailerData(pdfium::MakeUnique<TrailerData>()) {}
+      m_TrailerData(pdfium::MakeUnique<TrailerData>()) {
+  if (!holder) {
+    m_pOwnedObjectsHolder = pdfium::MakeUnique<ObjectsHolderStub>();
+    m_pObjectsHolder = m_pOwnedObjectsHolder.get();
+  }
+}
+
+CPDF_Parser::CPDF_Parser() : CPDF_Parser(nullptr) {}
 
 CPDF_Parser::~CPDF_Parser() {
   ReleaseEncryptHandler();
@@ -225,20 +240,19 @@ bool CPDF_Parser::ParseFileVersion() {
 
 CPDF_Parser::Error CPDF_Parser::StartParse(
     const RetainPtr<IFX_SeekableReadStream>& pFileAccess,
-    CPDF_Document* pDocument) {
+    const char* password) {
   if (!InitSyntaxParser(
           pdfium::MakeRetain<CPDF_ReadValidator>(pFileAccess, nullptr)))
     return FORMAT_ERROR;
-  return StartParseInternal(pDocument);
+  SetPassword(password);
+  return StartParseInternal();
 }
 
-CPDF_Parser::Error CPDF_Parser::StartParseInternal(CPDF_Document* pDocument) {
+CPDF_Parser::Error CPDF_Parser::StartParseInternal() {
   ASSERT(!m_bHasParsed);
   m_bHasParsed = true;
   m_bXRefStream = false;
 
-  m_pDocument = pDocument;
-
   bool bXRefRebuilt = false;
 
   m_LastXRefOffset = ParseStartXRef();
@@ -262,8 +276,7 @@ CPDF_Parser::Error CPDF_Parser::StartParseInternal(CPDF_Document* pDocument) {
   if (eRet != SUCCESS)
     return eRet;
 
-  m_pDocument->LoadDoc();
-  if (!m_pDocument->GetRoot() || m_pDocument->GetPageCount() == 0) {
+  if (!GetRoot() || !m_pObjectsHolder->TryInit()) {
     if (bXRefRebuilt)
       return FORMAT_ERROR;
 
@@ -275,8 +288,8 @@ CPDF_Parser::Error CPDF_Parser::StartParseInternal(CPDF_Document* pDocument) {
     if (eRet != SUCCESS)
       return eRet;
 
-    m_pDocument->LoadDoc();
-    if (!m_pDocument->GetRoot())
+    m_pObjectsHolder->TryInit();
+    if (!GetRoot())
       return FORMAT_ERROR;
   }
   if (GetRootObjNum() == CPDF_Object::kInvalidObjNum) {
@@ -290,7 +303,7 @@ CPDF_Parser::Error CPDF_Parser::StartParseInternal(CPDF_Document* pDocument) {
   }
   if (m_pSecurityHandler && !m_pSecurityHandler->IsMetadataEncrypted()) {
     CPDF_Reference* pMetadata =
-        ToReference(m_pDocument->GetRoot()->GetObjectFor("Metadata"));
+        ToReference(GetRoot()->GetObjectFor("Metadata"));
     if (pMetadata)
       m_MetadataObjnum = pMetadata->GetRefObjNum();
   }
@@ -330,7 +343,8 @@ CPDF_Parser::Error CPDF_Parser::SetEncryptHandler() {
     if (CPDF_Dictionary* pEncryptDict = pEncryptObj->AsDictionary()) {
       SetEncryptDictionary(pEncryptDict);
     } else if (CPDF_Reference* pRef = pEncryptObj->AsReference()) {
-      pEncryptObj = m_pDocument->GetOrParseIndirectObject(pRef->GetRefObjNum());
+      pEncryptObj =
+          m_pObjectsHolder->GetOrParseIndirectObject(pRef->GetRefObjNum());
       if (pEncryptObj)
         SetEncryptDictionary(pEncryptObj->GetDict());
     }
@@ -955,8 +969,7 @@ bool CPDF_Parser::RebuildCrossRef() {
 }
 
 bool CPDF_Parser::LoadCrossRefV5(FX_FILESIZE* pos, bool bMainXRef) {
-  std::unique_ptr<CPDF_Object> pObject(
-      ParseIndirectObjectAt(m_pDocument.Get(), *pos, 0));
+  std::unique_ptr<CPDF_Object> pObject(ParseIndirectObjectAt(*pos, 0));
   if (!pObject)
     return false;
 
@@ -965,14 +978,12 @@ bool CPDF_Parser::LoadCrossRefV5(FX_FILESIZE* pos, bool bMainXRef) {
     return false;
 
   CPDF_Object* pUnownedObject = pObject.get();
-  if (m_pDocument) {
-    const CPDF_Dictionary* pRootDict = m_pDocument->GetRoot();
-    if (pRootDict && pRootDict->GetObjNum() == objnum)
-      return false;
-    if (!m_pDocument->ReplaceIndirectObjectIfHigherGeneration(
-            objnum, std::move(pObject))) {
-      return false;
-    }
+  const CPDF_Dictionary* pRootDict = GetRoot();
+  if (pRootDict && pRootDict->GetObjNum() == objnum)
+    return false;
+  if (!m_pObjectsHolder->ReplaceIndirectObjectIfHigherGeneration(
+          objnum, std::move(pObject))) {
+    return false;
   }
 
   CPDF_Stream* pStream = pUnownedObject->AsStream();
@@ -1104,6 +1115,12 @@ const CPDF_Array* CPDF_Parser::GetIDArray() const {
   return GetTrailer() ? GetTrailer()->GetArrayFor("ID") : nullptr;
 }
 
+CPDF_Dictionary* CPDF_Parser::GetRoot() const {
+  CPDF_Object* obj =
+      m_pObjectsHolder->GetOrParseIndirectObject(GetRootObjNum());
+  return obj ? obj->GetDict() : nullptr;
+}
+
 CPDF_Dictionary* CPDF_Parser::GetTrailer() const {
   return m_TrailerData->GetMainTrailer();
 }
@@ -1121,7 +1138,6 @@ uint32_t CPDF_Parser::GetRootObjNum() const {
 }
 
 std::unique_ptr<CPDF_Object> CPDF_Parser::ParseIndirectObject(
-    CPDF_IndirectObjectHolder* pObjList,
     uint32_t objnum) {
   if (!IsValidObjectNumber(objnum))
     return nullptr;
@@ -1135,22 +1151,20 @@ std::unique_ptr<CPDF_Object> CPDF_Parser::ParseIndirectObject(
     FX_FILESIZE pos = m_ObjectInfo[objnum].pos;
     if (pos <= 0)
       return nullptr;
-    return ParseIndirectObjectAt(pObjList, pos, objnum);
+    return ParseIndirectObjectAt(pos, objnum);
   }
   if (GetObjectType(objnum) != ObjectType::kCompressed)
     return nullptr;
 
   const CPDF_ObjectStream* pObjStream =
-      GetObjectStream(pObjList, m_ObjectInfo[objnum].pos);
+      GetObjectStream(m_ObjectInfo[objnum].pos);
   if (!pObjStream)
     return nullptr;
 
-  return pObjStream->ParseObject(pObjList, objnum);
+  return pObjStream->ParseObject(m_pObjectsHolder.Get(), objnum);
 }
 
-const CPDF_ObjectStream* CPDF_Parser::GetObjectStream(
-    CPDF_IndirectObjectHolder* pObjList,
-    uint32_t object_number) {
+const CPDF_ObjectStream* CPDF_Parser::GetObjectStream(uint32_t object_number) {
   // Prevent circular parsing the same object.
   if (pdfium::ContainsKey(m_ParsingObjNums, object_number))
     return nullptr;
@@ -1167,7 +1181,7 @@ const CPDF_ObjectStream* CPDF_Parser::GetObjectStream(
     return nullptr;
 
   std::unique_ptr<CPDF_Object> object =
-      ParseIndirectObjectAt(pObjList, object_pos, object_number);
+      ParseIndirectObjectAt(object_pos, object_number);
   if (!object)
     return nullptr;
 
@@ -1180,22 +1194,21 @@ const CPDF_ObjectStream* CPDF_Parser::GetObjectStream(
 }
 
 std::unique_ptr<CPDF_Object> CPDF_Parser::ParseIndirectObjectAt(
-    CPDF_IndirectObjectHolder* pObjList,
     FX_FILESIZE pos,
     uint32_t objnum) {
   return ParseIndirectObjectAtInternal(
-      pObjList, pos, objnum, CPDF_SyntaxParser::ParseType::kLoose, nullptr);
+      pos, objnum, CPDF_SyntaxParser::ParseType::kLoose, nullptr);
 }
 
 std::unique_ptr<CPDF_Object> CPDF_Parser::ParseIndirectObjectAtInternal(
-    CPDF_IndirectObjectHolder* pObjList,
     FX_FILESIZE pos,
     uint32_t objnum,
     CPDF_SyntaxParser::ParseType parse_type,
     FX_FILESIZE* pResultPos) {
   const FX_FILESIZE saved_pos = m_pSyntax->GetPos();
   m_pSyntax->SetPos(pos);
-  auto result = m_pSyntax->GetIndirectObject(pObjList, parse_type);
+  auto result =
+      m_pSyntax->GetIndirectObject(m_pObjectsHolder.Get(), parse_type);
 
   if (pResultPos)
     *pResultPos = m_pSyntax->GetPos();
@@ -1215,12 +1228,11 @@ std::unique_ptr<CPDF_Object> CPDF_Parser::ParseIndirectObjectAtInternal(
 }
 
 std::unique_ptr<CPDF_Object> CPDF_Parser::ParseIndirectObjectAtByStrict(
-    CPDF_IndirectObjectHolder* pObjList,
     FX_FILESIZE pos,
     uint32_t objnum,
     FX_FILESIZE* pResultPos) {
   return ParseIndirectObjectAtInternal(
-      pObjList, pos, objnum, CPDF_SyntaxParser::ParseType::kStrict, pResultPos);
+      pos, objnum, CPDF_SyntaxParser::ParseType::kStrict, pResultPos);
 }
 
 uint32_t CPDF_Parser::GetFirstPageNo() const {
@@ -1236,7 +1248,7 @@ std::unique_ptr<CPDF_Dictionary> CPDF_Parser::LoadTrailerV4() {
   if (m_pSyntax->GetKeyword() != "trailer")
     return nullptr;
 
-  return ToDictionary(m_pSyntax->GetObjectBody(m_pDocument.Get()));
+  return ToDictionary(m_pSyntax->GetObjectBody(m_pObjectsHolder.Get()));
 }
 
 uint32_t CPDF_Parser::GetPermissions() const {
@@ -1258,8 +1270,9 @@ std::unique_ptr<CPDF_LinearizedHeader> CPDF_Parser::ParseLinearizedHeader() {
 
 CPDF_Parser::Error CPDF_Parser::StartLinearizedParse(
     const RetainPtr<CPDF_ReadValidator>& validator,
-    CPDF_Document* pDocument) {
+    const char* password) {
   ASSERT(!m_bHasParsed);
+  SetPassword(password);
   m_bXRefStream = false;
   m_LastXRefOffset = 0;
 
@@ -1268,10 +1281,9 @@ CPDF_Parser::Error CPDF_Parser::StartLinearizedParse(
 
   m_pLinearized = ParseLinearizedHeader();
   if (!m_pLinearized)
-    return StartParseInternal(std::move(pDocument));
+    return StartParseInternal();
 
   m_bHasParsed = true;
-  m_pDocument = pDocument;
 
   m_LastXRefOffset = m_pLinearized->GetLastXRefOffset();
   FX_FILESIZE dwFirstXRefOffset = m_LastXRefOffset;
@@ -1299,8 +1311,7 @@ CPDF_Parser::Error CPDF_Parser::StartLinearizedParse(
   if (eRet != SUCCESS)
     return eRet;
 
-  m_pDocument->LoadDoc();
-  if (!m_pDocument->GetRoot() || m_pDocument->GetPageCount() == 0) {
+  if (!GetRoot() || !m_pObjectsHolder->TryInit()) {
     if (bXRefRebuilt)
       return FORMAT_ERROR;
 
@@ -1312,8 +1323,8 @@ CPDF_Parser::Error CPDF_Parser::StartLinearizedParse(
     if (eRet != SUCCESS)
       return eRet;
 
-    m_pDocument->LoadDoc();
-    if (!m_pDocument->GetRoot())
+    m_pObjectsHolder->TryInit();
+    if (!GetRoot())
       return FORMAT_ERROR;
   }
 
@@ -1329,7 +1340,7 @@ CPDF_Parser::Error CPDF_Parser::StartLinearizedParse(
 
   if (m_pSecurityHandler && m_pSecurityHandler->IsMetadataEncrypted()) {
     if (CPDF_Reference* pMetadata =
-            ToReference(m_pDocument->GetRoot()->GetObjectFor("Metadata")))
+            ToReference(GetRoot()->GetObjectFor("Metadata")))
       m_MetadataObjnum = pMetadata->GetRefObjNum();
   }
   return SUCCESS;
diff --git a/core/fpdfapi/parser/cpdf_parser.h b/core/fpdfapi/parser/cpdf_parser.h
index f859db5d16..1a1f9b0de4 100644
--- a/core/fpdfapi/parser/cpdf_parser.h
+++ b/core/fpdfapi/parser/cpdf_parser.h
@@ -14,6 +14,7 @@
 #include <vector>
 
 #include "core/fpdfapi/parser/cpdf_cross_ref_table.h"
+#include "core/fpdfapi/parser/cpdf_indirect_object_holder.h"
 #include "core/fpdfapi/parser/cpdf_syntax_parser.h"
 #include "core/fxcrt/fx_string.h"
 #include "core/fxcrt/fx_system.h"
@@ -23,8 +24,6 @@
 class CPDF_Array;
 class CPDF_CryptoHandler;
 class CPDF_Dictionary;
-class CPDF_Document;
-class CPDF_IndirectObjectHolder;
 class CPDF_LinearizedHeader;
 class CPDF_Object;
 class CPDF_ObjectStream;
@@ -35,6 +34,11 @@ class IFX_SeekableReadStream;
 
 class CPDF_Parser {
  public:
+  class ParsedObjectsHolder : public CPDF_IndirectObjectHolder {
+   public:
+    virtual bool TryInit() = 0;
+  };
+
   enum Error {
     SUCCESS = 0,
     FILE_ERROR,
@@ -49,13 +53,14 @@ class CPDF_Parser {
 
   static const size_t kInvalidPos = std::numeric_limits<size_t>::max();
 
+  explicit CPDF_Parser(ParsedObjectsHolder* holder);
   CPDF_Parser();
   ~CPDF_Parser();
 
   Error StartParse(const RetainPtr<IFX_SeekableReadStream>& pFile,
-                   CPDF_Document* pDocument);
+                   const char* password);
   Error StartLinearizedParse(const RetainPtr<CPDF_ReadValidator>& validator,
-                             CPDF_Document* pDocument);
+                             const char* password);
 
   void SetPassword(const char* password) { m_Password = password; }
   ByteString GetPassword() const { return m_Password; }
@@ -72,12 +77,11 @@ class CPDF_Parser {
   uint32_t GetRootObjNum() const;
   uint32_t GetInfoObjNum() const;
   const CPDF_Array* GetIDArray() const;
+  CPDF_Dictionary* GetRoot() const;
 
   CPDF_Dictionary* GetEncryptDict() const { return m_pEncryptDict.Get(); }
 
-  std::unique_ptr<CPDF_Object> ParseIndirectObject(
-      CPDF_IndirectObjectHolder* pObjList,
-      uint32_t objnum);
+  std::unique_ptr<CPDF_Object> ParseIndirectObject(uint32_t objnum);
 
   uint32_t GetLastObjNum() const;
   bool IsValidObjectNumber(uint32_t objnum) const;
@@ -96,12 +100,10 @@ class CPDF_Parser {
   bool IsXRefStream() const { return m_bXRefStream; }
 
   std::unique_ptr<CPDF_Object> ParseIndirectObjectAt(
-      CPDF_IndirectObjectHolder* pObjList,
       FX_FILESIZE pos,
       uint32_t objnum);
 
   std::unique_ptr<CPDF_Object> ParseIndirectObjectAtByStrict(
-      CPDF_IndirectObjectHolder* pObjList,
       FX_FILESIZE pos,
       uint32_t objnum,
       FX_FILESIZE* pResultPos);
@@ -150,7 +152,7 @@ class CPDF_Parser {
     ObjectInfo info;
   };
 
-  Error StartParseInternal(CPDF_Document* pDocument);
+  Error StartParseInternal();
   FX_FILESIZE ParseStartXRef();
   bool LoadAllCrossRefV4(FX_FILESIZE pos);
   bool LoadAllCrossRefV5(FX_FILESIZE pos);
@@ -161,8 +163,7 @@ class CPDF_Parser {
   bool LoadLinearizedAllCrossRefV4(FX_FILESIZE pos);
   bool LoadLinearizedAllCrossRefV5(FX_FILESIZE pos);
   Error LoadLinearizedMainXRefTable();
-  const CPDF_ObjectStream* GetObjectStream(CPDF_IndirectObjectHolder* pObjList,
-                                           uint32_t object_number);
+  const CPDF_ObjectStream* GetObjectStream(uint32_t object_number);
   std::unique_ptr<CPDF_LinearizedHeader> ParseLinearizedHeader();
   void SetEncryptDictionary(CPDF_Dictionary* pDict);
   void ShrinkObjectMap(uint32_t size);
@@ -180,7 +181,6 @@ class CPDF_Parser {
   void MergeCrossRefObjectsData(const std::vector<CrossRefObjData>& objects);
 
   std::unique_ptr<CPDF_Object> ParseIndirectObjectAtInternal(
-      CPDF_IndirectObjectHolder* pObjList,
       FX_FILESIZE pos,
       uint32_t objnum,
       CPDF_SyntaxParser::ParseType parse_type,
@@ -193,7 +193,8 @@ class CPDF_Parser {
   ObjectType GetObjectTypeFromCrossRefStreamType(
       int cross_ref_stream_type) const;
 
-  UnownedPtr<CPDF_Document> m_pDocument;
+  std::unique_ptr<ParsedObjectsHolder> m_pOwnedObjectsHolder;
+  UnownedPtr<ParsedObjectsHolder> m_pObjectsHolder;
 
   bool m_bHasParsed;
   bool m_bXRefStream;