Store the offset in the archive buffer

This Cl moves the implementation of the archive buffer behind an
IFX_ArchiveStream interface. The buffer holds the current offset and the
offset parameter is removed from the CPDF_Creator and various other
methods.

Change-Id: Ia54e803b58bbfb6ef03fec4a940d2c056d541356
Reviewed-on: https://pdfium-review.googlesource.com/5255
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Commit-Queue: dsinclair <dsinclair@chromium.org>

19 files changed, 52 insertions, 137 deletions

diff --git a/core/fpdfapi/parser/cpdf_array.cpp b/core/fpdfapi/parser/cpdf_array.cpp
index aa10588f87..698cd6d0d0 100644
--- a/core/fpdfapi/parser/cpdf_array.cpp
+++ b/core/fpdfapi/parser/cpdf_array.cpp
@@ -194,31 +194,21 @@ CPDF_Object* CPDF_Array::Add(std::unique_ptr<CPDF_Object> pObj) {
   return pRet;
 }
 
-bool CPDF_Array::WriteTo(CFX_FileBufferArchive* archive,
-                         FX_FILESIZE* offset) const {
-  if (archive->AppendString("[") < 0)
+bool CPDF_Array::WriteTo(IFX_ArchiveStream* archive) const {
+  if (!archive->WriteString("["))
     return false;
-  *offset += 1;
 
   for (size_t i = 0; i < GetCount(); ++i) {
     CPDF_Object* pElement = GetObjectAt(i);
     if (!pElement->IsInline()) {
-      if (archive->AppendString(" ") < 0)
-        return false;
-
-      int32_t len = archive->AppendDWord(pElement->GetObjNum());
-      if (len < 0)
-        return false;
-      if (archive->AppendString(" 0 R") < 0)
-        return false;
-      *offset += len + 5;
-    } else {
-      if (!pElement->WriteTo(archive, offset))
+      if (!archive->WriteString(" ") ||
+          !archive->WriteDWord(pElement->GetObjNum()) ||
+          !archive->WriteString(" 0 R")) {
         return false;
+      }
+    } else if (!pElement->WriteTo(archive)) {
+      return false;
     }
   }
-  if (archive->AppendString("]") < 0)
-    return false;
-  *offset += 1;
-  return true;
+  return archive->WriteString("]");
 }
diff --git a/core/fpdfapi/parser/cpdf_array.h b/core/fpdfapi/parser/cpdf_array.h
index b788d1c075..aff65d1454 100644
--- a/core/fpdfapi/parser/cpdf_array.h
+++ b/core/fpdfapi/parser/cpdf_array.h
@@ -34,8 +34,7 @@ class CPDF_Array : public CPDF_Object {
   bool IsArray() const override;
   CPDF_Array* AsArray() override;
   const CPDF_Array* AsArray() const override;
-  bool WriteTo(CFX_FileBufferArchive* archive,
-               FX_FILESIZE* offset) const override;
+  bool WriteTo(IFX_ArchiveStream* archive) const override;
 
   bool IsEmpty() const { return m_Objects.empty(); }
   size_t GetCount() const { return m_Objects.size(); }
diff --git a/core/fpdfapi/parser/cpdf_boolean.cpp b/core/fpdfapi/parser/cpdf_boolean.cpp
index 1cee3a3a49..eb01c06332 100644
--- a/core/fpdfapi/parser/cpdf_boolean.cpp
+++ b/core/fpdfapi/parser/cpdf_boolean.cpp
@@ -45,14 +45,7 @@ const CPDF_Boolean* CPDF_Boolean::AsBoolean() const {
   return this;
 }
 
-bool CPDF_Boolean::WriteTo(CFX_FileBufferArchive* archive,
-                           FX_FILESIZE* offset) const {
-  if (archive->AppendString(" ") < 0)
-    return false;
-
-  int32_t len = archive->AppendString(GetString().AsStringC());
-  if (len < 0)
-    return false;
-  *offset += len + 1;
-  return true;
+bool CPDF_Boolean::WriteTo(IFX_ArchiveStream* archive) const {
+  return archive->WriteString(" ") &&
+         archive->WriteString(GetString().AsStringC());
 }
diff --git a/core/fpdfapi/parser/cpdf_boolean.h b/core/fpdfapi/parser/cpdf_boolean.h
index e859f4cf9c..2dd1486b6a 100644
--- a/core/fpdfapi/parser/cpdf_boolean.h
+++ b/core/fpdfapi/parser/cpdf_boolean.h
@@ -28,8 +28,7 @@ class CPDF_Boolean : public CPDF_Object {
   bool IsBoolean() const override;
   CPDF_Boolean* AsBoolean() override;
   const CPDF_Boolean* AsBoolean() const override;
-  bool WriteTo(CFX_FileBufferArchive* archive,
-               FX_FILESIZE* offset) const override;
+  bool WriteTo(IFX_ArchiveStream* archive) const override;
 
  protected:
   bool m_bValue;
diff --git a/core/fpdfapi/parser/cpdf_dictionary.cpp b/core/fpdfapi/parser/cpdf_dictionary.cpp
index 7d84083829..cbefb5d56d 100644
--- a/core/fpdfapi/parser/cpdf_dictionary.cpp
+++ b/core/fpdfapi/parser/cpdf_dictionary.cpp
@@ -239,40 +239,27 @@ CFX_ByteString CPDF_Dictionary::MaybeIntern(const CFX_ByteString& str) {
   return m_pPool ? m_pPool->Intern(str) : str;
 }
 
-bool CPDF_Dictionary::WriteTo(CFX_FileBufferArchive* archive,
-                              FX_FILESIZE* offset) const {
-  if (archive->AppendString("<<") < 0)
+bool CPDF_Dictionary::WriteTo(IFX_ArchiveStream* archive) const {
+  if (!archive->WriteString("<<"))
     return false;
-  *offset += 2;
 
   for (const auto& it : *this) {
     const CFX_ByteString& key = it.first;
     CPDF_Object* pValue = it.second.get();
-    if (archive->AppendString("/") < 0)
+    if (!archive->WriteString("/") ||
+        !archive->WriteString(PDF_NameEncode(key).AsStringC())) {
       return false;
-
-    int32_t len = archive->AppendString(PDF_NameEncode(key).AsStringC());
-    if (len < 0)
-      return false;
-    *offset += len + 1;
+    }
 
     if (!pValue->IsInline()) {
-      if (archive->AppendString(" ") < 0)
-        return false;
-
-      len = archive->AppendDWord(pValue->GetObjNum());
-      if (len < 0)
-        return false;
-      if (archive->AppendString(" 0 R") < 0)
-        return false;
-      *offset += len + 5;
-    } else {
-      if (!pValue->WriteTo(archive, offset))
+      if (!archive->WriteString(" ") ||
+          !archive->WriteDWord(pValue->GetObjNum()) ||
+          !archive->WriteString(" 0 R")) {
         return false;
+      }
+    } else if (!pValue->WriteTo(archive)) {
+      return false;
     }
   }
-  if (archive->AppendString(">>") < 0)
-    return false;
-  *offset += 2;
-  return true;
+  return archive->WriteString(">>");
 }
diff --git a/core/fpdfapi/parser/cpdf_dictionary.h b/core/fpdfapi/parser/cpdf_dictionary.h
index e4144c1524..f741299d2d 100644
--- a/core/fpdfapi/parser/cpdf_dictionary.h
+++ b/core/fpdfapi/parser/cpdf_dictionary.h
@@ -37,8 +37,7 @@ class CPDF_Dictionary : public CPDF_Object {
   bool IsDictionary() const override;
   CPDF_Dictionary* AsDictionary() override;
   const CPDF_Dictionary* AsDictionary() const override;
-  bool WriteTo(CFX_FileBufferArchive* archive,
-               FX_FILESIZE* offset) const override;
+  bool WriteTo(IFX_ArchiveStream* archive) const override;
 
   size_t GetCount() const { return m_Map.size(); }
   CPDF_Object* GetObjectFor(const CFX_ByteString& key) const;
diff --git a/core/fpdfapi/parser/cpdf_name.cpp b/core/fpdfapi/parser/cpdf_name.cpp
index 74c83b9d28..0287b7ab17 100644
--- a/core/fpdfapi/parser/cpdf_name.cpp
+++ b/core/fpdfapi/parser/cpdf_name.cpp
@@ -50,15 +50,7 @@ CFX_WideString CPDF_Name::GetUnicodeText() const {
   return PDF_DecodeText(m_Name);
 }
 
-bool CPDF_Name::WriteTo(CFX_FileBufferArchive* archive,
-                        FX_FILESIZE* offset) const {
-  if (archive->AppendString("/") < 0)
-    return false;
-
-  CFX_ByteString str = GetString();
-  int32_t len = archive->AppendString(PDF_NameEncode(str).AsStringC());
-  if (len < 0)
-    return false;
-  *offset += len + 1;
-  return true;
+bool CPDF_Name::WriteTo(IFX_ArchiveStream* archive) const {
+  return archive->WriteString("/") &&
+         archive->WriteString(PDF_NameEncode(GetString()).AsStringC());
 }
diff --git a/core/fpdfapi/parser/cpdf_name.h b/core/fpdfapi/parser/cpdf_name.h
index 8855f9785c..616f35f9bc 100644
--- a/core/fpdfapi/parser/cpdf_name.h
+++ b/core/fpdfapi/parser/cpdf_name.h
@@ -27,8 +27,7 @@ class CPDF_Name : public CPDF_Object {
   bool IsName() const override;
   CPDF_Name* AsName() override;
   const CPDF_Name* AsName() const override;
-  bool WriteTo(CFX_FileBufferArchive* archive,
-               FX_FILESIZE* offset) const override;
+  bool WriteTo(IFX_ArchiveStream* archive) const override;
 
  protected:
   CFX_ByteString m_Name;
diff --git a/core/fpdfapi/parser/cpdf_null.cpp b/core/fpdfapi/parser/cpdf_null.cpp
index b5e07e0c55..254c86fd7a 100644
--- a/core/fpdfapi/parser/cpdf_null.cpp
+++ b/core/fpdfapi/parser/cpdf_null.cpp
@@ -17,10 +17,6 @@ std::unique_ptr<CPDF_Object> CPDF_Null::Clone() const {
   return pdfium::MakeUnique<CPDF_Null>();
 }
 
-bool CPDF_Null::WriteTo(CFX_FileBufferArchive* archive,
-                        FX_FILESIZE* offset) const {
-  if (archive->AppendString(" null") < 0)
-    return false;
-  *offset += 5;
-  return true;
+bool CPDF_Null::WriteTo(IFX_ArchiveStream* archive) const {
+  return archive->WriteString(" null");
 }
diff --git a/core/fpdfapi/parser/cpdf_null.h b/core/fpdfapi/parser/cpdf_null.h
index b6b781b01a..92917281fb 100644
--- a/core/fpdfapi/parser/cpdf_null.h
+++ b/core/fpdfapi/parser/cpdf_null.h
@@ -18,8 +18,7 @@ class CPDF_Null : public CPDF_Object {
   // CPDF_Object.
   Type GetType() const override;
   std::unique_ptr<CPDF_Object> Clone() const override;
-  bool WriteTo(CFX_FileBufferArchive* archive,
-               FX_FILESIZE* offset) const override;
+  bool WriteTo(IFX_ArchiveStream* archive) 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
index 24665fff60..73d689fffe 100644
--- a/core/fpdfapi/parser/cpdf_number.cpp
+++ b/core/fpdfapi/parser/cpdf_number.cpp
@@ -56,14 +56,7 @@ CFX_ByteString CPDF_Number::GetString() const {
                     : CFX_ByteString::FormatFloat(m_Float);
 }
 
-bool CPDF_Number::WriteTo(CFX_FileBufferArchive* archive,
-                          FX_FILESIZE* offset) const {
-  if (archive->AppendString(" ") < 0)
-    return false;
-
-  int32_t len = archive->AppendString(GetString().AsStringC());
-  if (len < 0)
-    return false;
-  *offset += len + 1;
-  return true;
+bool CPDF_Number::WriteTo(IFX_ArchiveStream* archive) const {
+  return archive->WriteString(" ") &&
+         archive->WriteString(GetString().AsStringC());
 }
diff --git a/core/fpdfapi/parser/cpdf_number.h b/core/fpdfapi/parser/cpdf_number.h
index a5d866f835..57f82274cb 100644
--- a/core/fpdfapi/parser/cpdf_number.h
+++ b/core/fpdfapi/parser/cpdf_number.h
@@ -31,8 +31,7 @@ class CPDF_Number : public CPDF_Object {
   bool IsNumber() const override;
   CPDF_Number* AsNumber() override;
   const CPDF_Number* AsNumber() const override;
-  bool WriteTo(CFX_FileBufferArchive* archive,
-               FX_FILESIZE* offset) const override;
+  bool WriteTo(IFX_ArchiveStream* archive) const override;
 
   bool IsInteger() const { return m_bInteger; }
 
diff --git a/core/fpdfapi/parser/cpdf_object.h b/core/fpdfapi/parser/cpdf_object.h
index 8194256f5a..b0c1adf955 100644
--- a/core/fpdfapi/parser/cpdf_object.h
+++ b/core/fpdfapi/parser/cpdf_object.h
@@ -89,8 +89,7 @@ class CPDF_Object {
   virtual CPDF_String* AsString();
   virtual const CPDF_String* AsString() const;
 
-  virtual bool WriteTo(CFX_FileBufferArchive* archive,
-                       FX_FILESIZE* offset) const = 0;
+  virtual bool WriteTo(IFX_ArchiveStream* archive) const = 0;
 
  protected:
   friend class CPDF_Array;
diff --git a/core/fpdfapi/parser/cpdf_reference.cpp b/core/fpdfapi/parser/cpdf_reference.cpp
index 560fd27934..ff0442b6f5 100644
--- a/core/fpdfapi/parser/cpdf_reference.cpp
+++ b/core/fpdfapi/parser/cpdf_reference.cpp
@@ -83,15 +83,7 @@ CPDF_Object* CPDF_Reference::GetDirect() const {
                     : nullptr;
 }
 
-bool CPDF_Reference::WriteTo(CFX_FileBufferArchive* archive,
-                             FX_FILESIZE* offset) const {
-  if (archive->AppendString(" ") < 0)
-    return false;
-  int32_t len = archive->AppendDWord(GetRefObjNum());
-  if (len < 0)
-    return false;
-  if (archive->AppendString(" 0 R ") < 0)
-    return false;
-  *offset += len + 6;
-  return true;
+bool CPDF_Reference::WriteTo(IFX_ArchiveStream* archive) const {
+  return archive->WriteString(" ") && archive->WriteDWord(GetRefObjNum()) &&
+         archive->WriteString(" 0 R ");
 }
diff --git a/core/fpdfapi/parser/cpdf_reference.h b/core/fpdfapi/parser/cpdf_reference.h
index 4830cb5bf6..83bb0b48e7 100644
--- a/core/fpdfapi/parser/cpdf_reference.h
+++ b/core/fpdfapi/parser/cpdf_reference.h
@@ -30,8 +30,7 @@ class CPDF_Reference : public CPDF_Object {
   bool IsReference() const override;
   CPDF_Reference* AsReference() override;
   const CPDF_Reference* AsReference() const override;
-  bool WriteTo(CFX_FileBufferArchive* archive,
-               FX_FILESIZE* offset) const override;
+  bool WriteTo(IFX_ArchiveStream* archive) const override;
 
   CPDF_IndirectObjectHolder* GetObjList() const { return m_pObjList; }
   uint32_t GetRefObjNum() const { return m_RefObjNum; }
diff --git a/core/fpdfapi/parser/cpdf_stream.cpp b/core/fpdfapi/parser/cpdf_stream.cpp
index 7e2529e1d7..69a87e6d2e 100644
--- a/core/fpdfapi/parser/cpdf_stream.cpp
+++ b/core/fpdfapi/parser/cpdf_stream.cpp
@@ -132,24 +132,12 @@ CFX_WideString CPDF_Stream::GetUnicodeText() const {
   return PDF_DecodeText(pAcc->GetData(), pAcc->GetSize());
 }
 
-bool CPDF_Stream::WriteTo(CFX_FileBufferArchive* archive,
-                          FX_FILESIZE* offset) const {
-  if (!GetDict()->WriteTo(archive, offset))
+bool CPDF_Stream::WriteTo(IFX_ArchiveStream* archive) const {
+  if (!GetDict()->WriteTo(archive) || !archive->WriteString("stream\r\n"))
     return false;
-  if (archive->AppendString("stream\r\n") < 0)
-    return false;
-  *offset += 8;
 
   auto pAcc = pdfium::MakeRetain<CPDF_StreamAcc>(this);
   pAcc->LoadAllData(true);
-  if (archive->AppendBlock(pAcc->GetData(), pAcc->GetSize()) < 0)
-    return false;
-  *offset += pAcc->GetSize();
-
-  int32_t len = archive->AppendString("\r\nendstream");
-  if (len < 0)
-    return false;
-
-  *offset += len;
-  return true;
+  return archive->WriteBlock(pAcc->GetData(), pAcc->GetSize()) &&
+         archive->WriteString("\r\nendstream");
 }
diff --git a/core/fpdfapi/parser/cpdf_stream.h b/core/fpdfapi/parser/cpdf_stream.h
index 4f76953efe..82cc01aef3 100644
--- a/core/fpdfapi/parser/cpdf_stream.h
+++ b/core/fpdfapi/parser/cpdf_stream.h
@@ -33,8 +33,7 @@ class CPDF_Stream : public CPDF_Object {
   bool IsStream() const override;
   CPDF_Stream* AsStream() override;
   const CPDF_Stream* AsStream() const override;
-  bool WriteTo(CFX_FileBufferArchive* archive,
-               FX_FILESIZE* offset) const override;
+  bool WriteTo(IFX_ArchiveStream* archive) const override;
 
   uint32_t GetRawSize() const { return m_dwSize; }
   uint8_t* GetRawData() const { return m_pDataBuf.get(); }
diff --git a/core/fpdfapi/parser/cpdf_string.cpp b/core/fpdfapi/parser/cpdf_string.cpp
index 01cf3ff1b0..74a2733fc5 100644
--- a/core/fpdfapi/parser/cpdf_string.cpp
+++ b/core/fpdfapi/parser/cpdf_string.cpp
@@ -65,13 +65,7 @@ CFX_WideString CPDF_String::GetUnicodeText() const {
   return PDF_DecodeText(m_String);
 }
 
-bool CPDF_String::WriteTo(CFX_FileBufferArchive* archive,
-                          FX_FILESIZE* offset) const {
-  CFX_ByteString str = GetString();
-  int32_t len =
-      archive->AppendString(PDF_EncodeString(str, IsHex()).AsStringC());
-  if (len < 0)
-    return false;
-  *offset += len;
-  return true;
+bool CPDF_String::WriteTo(IFX_ArchiveStream* archive) const {
+  return archive->WriteString(
+      PDF_EncodeString(GetString(), IsHex()).AsStringC());
 }
diff --git a/core/fpdfapi/parser/cpdf_string.h b/core/fpdfapi/parser/cpdf_string.h
index f895535a92..ccd6f530c1 100644
--- a/core/fpdfapi/parser/cpdf_string.h
+++ b/core/fpdfapi/parser/cpdf_string.h
@@ -33,8 +33,7 @@ class CPDF_String : public CPDF_Object {
   bool IsString() const override;
   CPDF_String* AsString() override;
   const CPDF_String* AsString() const override;
-  bool WriteTo(CFX_FileBufferArchive* archive,
-               FX_FILESIZE* offset) const override;
+  bool WriteTo(IFX_ArchiveStream* archive) const override;
 
   bool IsHex() const { return m_bHex; }