Move parser pointer to CPDF_Document

The CPDF_IndirectObjectHolder has two subclasses, CPDF_Document and
CFDF_Document. The CPDF document requires the parser and the CFDF document
does not. This cl moves the parser pointer up to CPDF_Document.

Review-Url: https://codereview.chromium.org/2253723002

13 files changed, 118 insertions, 87 deletions

diff --git a/core/fpdfapi/fpdf_edit/fpdf_edit_create.cpp b/core/fpdfapi/fpdf_edit/fpdf_edit_create.cpp
index c20a483764..eb3f156b2d 100644
--- a/core/fpdfapi/fpdf_edit/fpdf_edit_create.cpp
+++ b/core/fpdfapi/fpdf_edit/fpdf_edit_create.cpp
@@ -1233,13 +1233,12 @@ int32_t CPDF_Creator::WriteOldIndirectObject(uint32_t objnum) {
     return 0;
 
   m_ObjectOffset[objnum] = m_Offset;
-  FX_BOOL bExistInMap =
-      pdfium::ContainsKey(m_pDocument->m_IndirectObjs, objnum);
+  FX_BOOL bExistInMap = !!m_pDocument->GetIndirectObject(objnum);
   const uint8_t object_type = m_pParser->GetObjectType(objnum);
   bool bObjStm = (object_type == 2) && m_pEncryptDict && !m_pXRefStream;
   if (m_pParser->IsVersionUpdated() || m_bSecurityChanged || bExistInMap ||
       bObjStm) {
-    CPDF_Object* pObj = m_pDocument->GetIndirectObject(objnum);
+    CPDF_Object* pObj = m_pDocument->GetOrParseIndirectObject(objnum);
     if (!pObj) {
       m_ObjectOffset[objnum] = 0;
       return 0;
@@ -1320,13 +1319,13 @@ int32_t CPDF_Creator::WriteNewObjs(FX_BOOL bIncremental, IFX_Pause* pPause) {
   int32_t index = (int32_t)(uintptr_t)m_Pos;
   while (index < iCount) {
     uint32_t objnum = m_NewObjNumArray.ElementAt(index);
-    auto it = m_pDocument->m_IndirectObjs.find(objnum);
-    if (it == m_pDocument->m_IndirectObjs.end()) {
+    CPDF_Object* pObj = m_pDocument->GetIndirectObject(objnum);
+    if (!pObj) {
       ++index;
       continue;
     }
     m_ObjectOffset[objnum] = m_Offset;
-    if (WriteIndirectObj(it->second)) {
+    if (WriteIndirectObj(pObj)) {
       return -1;
     }
     index++;
@@ -1363,7 +1362,7 @@ void CPDF_Creator::InitOldObjNumOffsets() {
 void CPDF_Creator::InitNewObjNumOffsets() {
   FX_BOOL bIncremental = (m_dwFlags & FPDFCREATE_INCREMENTAL) != 0;
   FX_BOOL bNoOriginal = (m_dwFlags & FPDFCREATE_NO_ORIGINAL) != 0;
-  for (const auto& pair : m_pDocument->m_IndirectObjs) {
+  for (const auto& pair : *m_pDocument) {
     const uint32_t objnum = pair.first;
     const CPDF_Object* pObj = pair.second;
     if (bIncremental || pObj->GetObjNum() == CPDF_Object::kInvalidObjNum)
@@ -1703,7 +1702,7 @@ int32_t CPDF_Creator::WriteDoc_Stage4(IFX_Pause* pPause) {
         return -1;
       }
     } else {
-      if (m_File.AppendDWord(m_pDocument->m_LastObjNum + 1) < 0) {
+      if (m_File.AppendDWord(m_pDocument->GetLastObjNum() + 1) < 0) {
         return -1;
       }
       if (m_File.AppendString(" 0 obj <<") < 0) {
diff --git a/core/fpdfapi/fpdf_parser/cfdf_document.cpp b/core/fpdfapi/fpdf_parser/cfdf_document.cpp
index c039871401..f286346d70 100644
--- a/core/fpdfapi/fpdf_parser/cfdf_document.cpp
+++ b/core/fpdfapi/fpdf_parser/cfdf_document.cpp
@@ -10,16 +10,17 @@
 #include "core/fpdfapi/fpdf_parser/cpdf_syntax_parser.h"
 #include "core/fpdfapi/fpdf_parser/include/cpdf_dictionary.h"
 
-CFDF_Document::CFDF_Document() : CPDF_IndirectObjectHolder(nullptr) {
-  m_pRootDict = nullptr;
-  m_pFile = nullptr;
-  m_bOwnFile = FALSE;
-}
+CFDF_Document::CFDF_Document()
+    : CPDF_IndirectObjectHolder(),
+      m_pRootDict(nullptr),
+      m_pFile(nullptr),
+      m_bOwnFile(FALSE) {}
+
 CFDF_Document::~CFDF_Document() {
-  if (m_bOwnFile && m_pFile) {
+  if (m_bOwnFile && m_pFile)
     m_pFile->Release();
-  }
 }
+
 CFDF_Document* CFDF_Document::CreateNewDoc() {
   CFDF_Document* pDoc = new CFDF_Document;
   pDoc->m_pRootDict = new CPDF_Dictionary;
@@ -65,7 +66,7 @@ void CFDF_Document::ParseStream(IFX_FileRead* pFile, FX_BOOL bOwnFile) {
       if (!pObj)
         break;
 
-      InsertIndirectObject(objnum, pObj);
+      ReplaceIndirectObjectIfHigherGeneration(objnum, pObj);
       word = parser.GetNextWord(nullptr);
       if (word != "endobj")
         break;
@@ -88,9 +89,9 @@ FX_BOOL CFDF_Document::WriteBuf(CFX_ByteTextBuf& buf) const {
     return FALSE;
   }
   buf << "%FDF-1.2\r\n";
-  for (const auto& pair : m_IndirectObjs) {
+  for (const auto& pair : *this)
     buf << pair.first << " 0 obj\r\n" << pair.second << "\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/fpdf_parser/cpdf_array_unittest.cpp b/core/fpdfapi/fpdf_parser/cpdf_array_unittest.cpp
index 12a36d921a..58a47a4ab7 100644
--- a/core/fpdfapi/fpdf_parser/cpdf_array_unittest.cpp
+++ b/core/fpdfapi/fpdf_parser/cpdf_array_unittest.cpp
@@ -109,14 +109,14 @@ TEST(cpdf_array, Clone) {
     ScopedArray arr(new CPDF_Array);
     // Indirect references to indirect objects.
     std::unique_ptr<CPDF_IndirectObjectHolder> obj_holder(
-        new CPDF_IndirectObjectHolder(nullptr));
+        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->InsertIndirectObject(obj_num, obj);
+        obj_holder->ReplaceIndirectObjectIfHigherGeneration(obj_num, obj);
         arr_elem->InsertAt(j, new CPDF_Reference(obj_holder.get(), obj_num),
                            obj_holder.get());
       }
diff --git a/core/fpdfapi/fpdf_parser/cpdf_data_avail.cpp b/core/fpdfapi/fpdf_parser/cpdf_data_avail.cpp
index 94795fd60e..58b69257ad 100644
--- a/core/fpdfapi/fpdf_parser/cpdf_data_avail.cpp
+++ b/core/fpdfapi/fpdf_parser/cpdf_data_avail.cpp
@@ -176,7 +176,7 @@ FX_BOOL CPDF_DataAvail::IsObjectsAvail(
         } else if (!pdfium::ContainsKey(m_ObjectSet, dwNum)) {
           m_ObjectSet.insert(dwNum);
           CPDF_Object* pReferred =
-              m_pDocument->GetIndirectObject(pRef->GetRefObjNum());
+              m_pDocument->GetOrParseIndirectObject(pRef->GetRefObjNum());
           if (pReferred)
             new_obj_array.Add(pReferred);
         }
@@ -1788,8 +1788,10 @@ CPDF_Dictionary* CPDF_DataAvail::GetPage(int index) {
       if (!pPageDict)
         return nullptr;
 
-      if (!m_pDocument->InsertIndirectObject(dwObjNum, pPageDict))
+      if (!m_pDocument->ReplaceIndirectObjectIfHigherGeneration(dwObjNum,
+                                                                pPageDict)) {
         return nullptr;
+      }
       return pPageDict->GetDict();
     }
   }
diff --git a/core/fpdfapi/fpdf_parser/cpdf_document.cpp b/core/fpdfapi/fpdf_parser/cpdf_document.cpp
index bf1f93f887..1f04373e3b 100644
--- a/core/fpdfapi/fpdf_parser/cpdf_document.cpp
+++ b/core/fpdfapi/fpdf_parser/cpdf_document.cpp
@@ -482,24 +482,32 @@ int CountPages(CPDF_Dictionary* pPages,
 }  // namespace
 
 CPDF_Document::CPDF_Document(CPDF_Parser* pParser)
-    : CPDF_IndirectObjectHolder(pParser),
+    : CPDF_IndirectObjectHolder(),
+      m_pParser(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_pDocRender(new CPDF_DocRenderData(this)) {
+  if (pParser)
+    SetLastObjNum(m_pParser->GetLastObjNum());
+}
 
 CPDF_Document::~CPDF_Document() {
   delete m_pDocPage;
   CPDF_ModuleMgr::Get()->GetPageModule()->ClearStockFont(this);
 }
 
+CPDF_Object* CPDF_Document::ParseIndirectObject(uint32_t objnum) {
+  return m_pParser ? m_pParser->ParseIndirectObject(this, objnum) : nullptr;
+}
+
 void CPDF_Document::LoadDocInternal() {
-  m_LastObjNum = m_pParser->GetLastObjNum();
+  SetLastObjNum(m_pParser->GetLastObjNum());
 
-  CPDF_Object* pRootObj = GetIndirectObject(m_pParser->GetRootObjNum());
+  CPDF_Object* pRootObj = GetOrParseIndirectObject(m_pParser->GetRootObjNum());
   if (!pRootObj)
     return;
 
@@ -507,7 +515,7 @@ void CPDF_Document::LoadDocInternal() {
   if (!m_pRootDict)
     return;
 
-  CPDF_Object* pInfoObj = GetIndirectObject(m_pParser->GetInfoObjNum());
+  CPDF_Object* pInfoObj = GetOrParseIndirectObject(m_pParser->GetInfoObjNum());
   if (pInfoObj)
     m_pInfoDict = pInfoObj->GetDict();
   if (CPDF_Array* pIDArray = m_pParser->GetIDArray()) {
@@ -587,14 +595,14 @@ CPDF_Dictionary* CPDF_Document::GetPage(int iPage) {
 
   if (m_bLinearized && (iPage == m_iFirstPageNo)) {
     if (CPDF_Dictionary* pDict =
-            ToDictionary(GetIndirectObject(m_dwFirstPageObjNum))) {
+            ToDictionary(GetOrParseIndirectObject(m_dwFirstPageObjNum))) {
       return pDict;
     }
   }
 
   int objnum = m_PageList.GetAt(iPage);
   if (objnum) {
-    if (CPDF_Dictionary* pDict = ToDictionary(GetIndirectObject(objnum)))
+    if (CPDF_Dictionary* pDict = ToDictionary(GetOrParseIndirectObject(objnum)))
       return pDict;
   }
 
@@ -727,9 +735,8 @@ uint32_t CPDF_Document::GetUserPermissions() const {
 }
 
 FX_BOOL CPDF_Document::IsFormStream(uint32_t objnum, FX_BOOL& bForm) const {
-  auto it = m_IndirectObjs.find(objnum);
-  if (it != m_IndirectObjs.end()) {
-    CPDF_Stream* pStream = it->second->AsStream();
+  if (CPDF_Object* pObj = GetIndirectObject(objnum)) {
+    CPDF_Stream* pStream = pObj->AsStream();
     bForm = pStream && pStream->GetDict()->GetStringBy("Subtype") == "Form";
     return TRUE;
   }
diff --git a/core/fpdfapi/fpdf_parser/cpdf_indirect_object_holder.cpp b/core/fpdfapi/fpdf_parser/cpdf_indirect_object_holder.cpp
index 33f45a53bf..0d3e68e86f 100644
--- a/core/fpdfapi/fpdf_parser/cpdf_indirect_object_holder.cpp
+++ b/core/fpdfapi/fpdf_parser/cpdf_indirect_object_holder.cpp
@@ -9,39 +9,38 @@
 #include "core/fpdfapi/fpdf_parser/include/cpdf_object.h"
 #include "core/fpdfapi/fpdf_parser/include/cpdf_parser.h"
 
-CPDF_IndirectObjectHolder::CPDF_IndirectObjectHolder(CPDF_Parser* pParser)
-    : m_pParser(pParser), m_LastObjNum(0) {
-  if (pParser)
-    m_LastObjNum = m_pParser->GetLastObjNum();
-}
+CPDF_IndirectObjectHolder::CPDF_IndirectObjectHolder() : m_LastObjNum(0) {}
 
 CPDF_IndirectObjectHolder::~CPDF_IndirectObjectHolder() {
   for (const auto& pair : m_IndirectObjs)
     pair.second->Destroy();
 }
 
-CPDF_Object* CPDF_IndirectObjectHolder::GetIndirectObject(uint32_t objnum) {
+CPDF_Object* CPDF_IndirectObjectHolder::GetIndirectObject(
+    uint32_t objnum) const {
   if (objnum == 0)
     return nullptr;
 
   auto it = m_IndirectObjs.find(objnum);
-  if (it != m_IndirectObjs.end())
-    return it->second->GetObjNum() != CPDF_Object::kInvalidObjNum ? it->second
-                                                                  : nullptr;
+  return it != m_IndirectObjs.end() ? it->second : nullptr;
+}
 
-  if (!m_pParser)
-    return nullptr;
+CPDF_Object* CPDF_IndirectObjectHolder::ParseIndirectObject(uint32_t objnum) {
+  return nullptr;
+}
 
-  CPDF_Object* pObj = m_pParser->ParseIndirectObject(this, objnum);
+CPDF_Object* CPDF_IndirectObjectHolder::GetOrParseIndirectObject(
+    uint32_t objnum) {
+  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);
-  if (m_IndirectObjs[objnum])
-    m_IndirectObjs[objnum]->Destroy();
-
-  m_IndirectObjs[objnum] = pObj;
+  ReplaceIndirectObject(pObj);
   return pObj;
 }
 
@@ -50,36 +49,41 @@ uint32_t CPDF_IndirectObjectHolder::AddIndirectObject(CPDF_Object* pObj) {
     return pObj->m_ObjNum;
 
   m_LastObjNum++;
-  m_IndirectObjs[m_LastObjNum] = pObj;
   pObj->m_ObjNum = m_LastObjNum;
+  ReplaceIndirectObject(pObj);
   return m_LastObjNum;
 }
 
 void CPDF_IndirectObjectHolder::ReleaseIndirectObject(uint32_t objnum) {
-  auto it = m_IndirectObjs.find(objnum);
-  if (it == m_IndirectObjs.end() ||
-      it->second->GetObjNum() == CPDF_Object::kInvalidObjNum) {
+  CPDF_Object* pObj = GetIndirectObject(objnum);
+  if (!pObj || pObj->m_ObjNum == CPDF_Object::kInvalidObjNum)
     return;
-  }
-  it->second->Destroy();
-  m_IndirectObjs.erase(it);
+
+  pObj->Destroy();
+  m_IndirectObjs.erase(objnum);
 }
 
-bool CPDF_IndirectObjectHolder::InsertIndirectObject(uint32_t objnum,
-                                                     CPDF_Object* pObj) {
+bool CPDF_IndirectObjectHolder::ReplaceIndirectObjectIfHigherGeneration(
+    uint32_t objnum,
+    CPDF_Object* pObj) {
   if (!objnum || !pObj)
     return false;
 
-  auto it = m_IndirectObjs.find(objnum);
-  if (it != m_IndirectObjs.end()) {
-    if (pObj->GetGenNum() <= it->second->GetGenNum()) {
-      pObj->Destroy();
-      return false;
-    }
-    it->second->Destroy();
+  CPDF_Object* pOldObj = GetIndirectObject(objnum);
+  if (pOldObj && pObj->GetGenNum() <= pOldObj->GetGenNum()) {
+    pObj->Destroy();
+    return false;
   }
+
   pObj->m_ObjNum = objnum;
-  m_IndirectObjs[objnum] = pObj;
-  m_LastObjNum = std::max(m_LastObjNum, objnum);
+  ReplaceIndirectObject(pObj);
   return true;
 }
+
+void CPDF_IndirectObjectHolder::ReplaceIndirectObject(CPDF_Object* pObj) {
+  m_LastObjNum = std::max(m_LastObjNum, pObj->m_ObjNum);
+  if (m_IndirectObjs[pObj->m_ObjNum])
+    m_IndirectObjs[pObj->m_ObjNum]->Destroy();
+
+  m_IndirectObjs[pObj->m_ObjNum] = pObj;
+}
diff --git a/core/fpdfapi/fpdf_parser/cpdf_object_unittest.cpp b/core/fpdfapi/fpdf_parser/cpdf_object_unittest.cpp
index a77f022c40..8fbaa482bf 100644
--- a/core/fpdfapi/fpdf_parser/cpdf_object_unittest.cpp
+++ b/core/fpdfapi/fpdf_parser/cpdf_object_unittest.cpp
@@ -92,7 +92,7 @@ class PDFObjectsTest : public testing::Test {
       m_DirectObjs.emplace_back(objs[i]);
 
     // Indirect references to indirect objects.
-    m_ObjHolder.reset(new CPDF_IndirectObjectHolder(nullptr));
+    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) {
@@ -710,7 +710,7 @@ TEST(PDFArrayTest, AddStringAndName) {
 
 TEST(PDFArrayTest, AddReferenceAndGetObjectAt) {
   std::unique_ptr<CPDF_IndirectObjectHolder> holder(
-      new CPDF_IndirectObjectHolder(nullptr));
+      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);
@@ -725,13 +725,14 @@ TEST(PDFArrayTest, AddReferenceAndGetObjectAt) {
   // 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->InsertIndirectObject(obj_nums[i], indirect_objs[i]);
+    holder->ReplaceIndirectObjectIfHigherGeneration(obj_nums[i],
+                                                    indirect_objs[i]);
     arr->AddReference(holder.get(), obj_nums[i]);
     arr1->AddReference(holder.get(), indirect_objs[i]);
   }
   // Check indirect objects.
   for (size_t i = 0; i < FX_ArraySize(obj_nums); ++i)
-    EXPECT_EQ(indirect_objs[i], holder->GetIndirectObject(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) {
diff --git a/core/fpdfapi/fpdf_parser/cpdf_parser.cpp b/core/fpdfapi/fpdf_parser/cpdf_parser.cpp
index b2f1a4be3f..ffd3f79a62 100644
--- a/core/fpdfapi/fpdf_parser/cpdf_parser.cpp
+++ b/core/fpdfapi/fpdf_parser/cpdf_parser.cpp
@@ -267,7 +267,7 @@ CPDF_Parser::Error CPDF_Parser::SetEncryptHandler() {
     if (CPDF_Dictionary* pEncryptDict = pEncryptObj->AsDictionary()) {
       SetEncryptDictionary(pEncryptDict);
     } else if (CPDF_Reference* pRef = pEncryptObj->AsReference()) {
-      pEncryptObj = m_pDocument->GetIndirectObject(pRef->GetRefObjNum());
+      pEncryptObj = m_pDocument->GetOrParseIndirectObject(pRef->GetRefObjNum());
       if (pEncryptObj)
         SetEncryptDictionary(pEncryptObj->GetDict());
     }
@@ -982,12 +982,16 @@ FX_BOOL CPDF_Parser::LoadCrossRefV5(FX_FILESIZE* pos, FX_BOOL bMainXRef) {
   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->InsertIndirectObject(pObject->m_ObjNum, pObject))
+    if (!m_pDocument->ReplaceIndirectObjectIfHigherGeneration(pObject->m_ObjNum,
+                                                              pObject)) {
       return FALSE;
+    }
   }
 
   CPDF_Stream* pStream = pObject->AsStream();
@@ -1230,7 +1234,8 @@ CPDF_StreamAcc* CPDF_Parser::GetObjectStream(uint32_t objnum) {
   if (!m_pDocument)
     return nullptr;
 
-  const CPDF_Stream* pStream = ToStream(m_pDocument->GetIndirectObject(objnum));
+  const CPDF_Stream* pStream =
+      ToStream(m_pDocument->GetOrParseIndirectObject(objnum));
   if (!pStream)
     return nullptr;
 
diff --git a/core/fpdfapi/fpdf_parser/cpdf_reference.cpp b/core/fpdfapi/fpdf_parser/cpdf_reference.cpp
index 007423e5fb..afda50c324 100644
--- a/core/fpdfapi/fpdf_parser/cpdf_reference.cpp
+++ b/core/fpdfapi/fpdf_parser/cpdf_reference.cpp
@@ -63,5 +63,6 @@ void CPDF_Reference::SetRef(CPDF_IndirectObjectHolder* pDoc, uint32_t objnum) {
 }
 
 CPDF_Object* CPDF_Reference::GetDirect() const {
-  return m_pObjList ? m_pObjList->GetIndirectObject(m_RefObjNum) : nullptr;
+  return m_pObjList ? m_pObjList->GetOrParseIndirectObject(m_RefObjNum)
+                    : nullptr;
 }
diff --git a/core/fpdfapi/fpdf_parser/include/cfdf_document.h b/core/fpdfapi/fpdf_parser/include/cfdf_document.h
index 18b9442fa9..834aecd1ba 100644
--- a/core/fpdfapi/fpdf_parser/include/cfdf_document.h
+++ b/core/fpdfapi/fpdf_parser/include/cfdf_document.h
@@ -19,7 +19,7 @@ class CFDF_Document : public CPDF_IndirectObjectHolder {
   static CFDF_Document* ParseFile(IFX_FileRead* pFile,
                                   FX_BOOL bOwnFile = FALSE);
   static CFDF_Document* ParseMemory(const uint8_t* pData, uint32_t size);
-  ~CFDF_Document();
+  ~CFDF_Document() override;
 
   FX_BOOL WriteBuf(CFX_ByteTextBuf& buf) const;
   CPDF_Dictionary* GetRoot() const { return m_pRootDict; }
diff --git a/core/fpdfapi/fpdf_parser/include/cpdf_document.h b/core/fpdfapi/fpdf_parser/include/cpdf_document.h
index 4a12ea97dc..adb8587f4f 100644
--- a/core/fpdfapi/fpdf_parser/include/cpdf_document.h
+++ b/core/fpdfapi/fpdf_parser/include/cpdf_document.h
@@ -40,7 +40,7 @@ class JBig2_DocumentContext;
 class CPDF_Document : public CPDF_IndirectObjectHolder {
  public:
   explicit CPDF_Document(CPDF_Parser* pParser);
-  ~CPDF_Document();
+  ~CPDF_Document() override;
 
   CPDF_Parser* GetParser() const { return m_pParser; }
   CPDF_Dictionary* GetRoot() const { return m_pRootDict; }
@@ -125,7 +125,9 @@ class CPDF_Document : public CPDF_IndirectObjectHolder {
                     int& index,
                     int level = 0);
   FX_BOOL CheckOCGVisible(CPDF_Dictionary* pOCG, FX_BOOL bPrinting);
+  CPDF_Object* ParseIndirectObject(uint32_t objnum) override;
 
+  CPDF_Parser* m_pParser;
   CPDF_Dictionary* m_pRootDict;
   CPDF_Dictionary* m_pInfoDict;
   CFX_ByteString m_ID1;
diff --git a/core/fpdfapi/fpdf_parser/include/cpdf_indirect_object_holder.h b/core/fpdfapi/fpdf_parser/include/cpdf_indirect_object_holder.h
index c29746fdd7..63fadf19d6 100644
--- a/core/fpdfapi/fpdf_parser/include/cpdf_indirect_object_holder.h
+++ b/core/fpdfapi/fpdf_parser/include/cpdf_indirect_object_holder.h
@@ -19,24 +19,32 @@ class CPDF_IndirectObjectHolder {
   using iterator = std::map<uint32_t, CPDF_Object*>::iterator;
   using const_iterator = std::map<uint32_t, CPDF_Object*>::const_iterator;
 
-  explicit CPDF_IndirectObjectHolder(CPDF_Parser* pParser);
-  ~CPDF_IndirectObjectHolder();
+  CPDF_IndirectObjectHolder();
+  virtual ~CPDF_IndirectObjectHolder();
+
+  CPDF_Object* GetIndirectObject(uint32_t objnum) const;
+  CPDF_Object* GetOrParseIndirectObject(uint32_t objnum);
 
-  CPDF_Object* GetIndirectObject(uint32_t objnum);
-  uint32_t AddIndirectObject(CPDF_Object* pObj);
   void ReleaseIndirectObject(uint32_t objnum);
 
-  // Takes ownership of |pObj|.
-  bool InsertIndirectObject(uint32_t objnum, CPDF_Object* pObj);
+  // The following take ownership of |pObj|.
+  uint32_t AddIndirectObject(CPDF_Object* pObj);
+  void ReplaceIndirectObject(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; }
+
   iterator begin() { return m_IndirectObjs.begin(); }
   const_iterator begin() const { return m_IndirectObjs.begin(); }
   iterator end() { return m_IndirectObjs.end(); }
   const_iterator end() const { return m_IndirectObjs.end(); }
 
  protected:
-  CPDF_Parser* m_pParser;
+  virtual CPDF_Object* ParseIndirectObject(uint32_t objnum);
+
+ private:
   uint32_t m_LastObjNum;
   std::map<uint32_t, CPDF_Object*> m_IndirectObjs;
 };
diff --git a/core/fpdfapi/fpdf_parser/include/cpdf_object.h b/core/fpdfapi/fpdf_parser/include/cpdf_object.h
index f637e36667..86f3879ce1 100644
--- a/core/fpdfapi/fpdf_parser/include/cpdf_object.h
+++ b/core/fpdfapi/fpdf_parser/include/cpdf_object.h
@@ -79,6 +79,10 @@ class CPDF_Object {
   virtual const CPDF_String* AsString() const;
 
  protected:
+  friend class CPDF_Document;
+  friend class CPDF_IndirectObjectHolder;
+  friend class CPDF_Parser;
+
   CPDF_Object() : m_ObjNum(0), m_GenNum(0) {}
   virtual ~CPDF_Object();
   void Destroy() { delete this; }
@@ -86,9 +90,6 @@ class CPDF_Object {
   uint32_t m_ObjNum;
   uint32_t m_GenNum;
 
-  friend class CPDF_IndirectObjectHolder;
-  friend class CPDF_Parser;
-
  private:
   CPDF_Object(const CPDF_Object& src) {}
 };