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// Copyright 2017 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/edit/cpdf_objectstream.h"
#include "core/fpdfapi/edit/cpdf_creator.h"
#include "core/fpdfapi/edit/cpdf_encryptor.h"
#include "core/fpdfapi/edit/cpdf_flateencoder.h"
#include "core/fpdfapi/parser/fpdf_parser_utility.h"
namespace {
const int kObjectStreamMaxLength = 256 * 1024;
} // namespace
CPDF_ObjectStream::CPDF_ObjectStream() : m_dwObjNum(0), m_index(0) {}
CPDF_ObjectStream::~CPDF_ObjectStream() {}
bool CPDF_ObjectStream::IsNotFull() const {
return m_Buffer.GetLength() < kObjectStreamMaxLength;
}
void CPDF_ObjectStream::Start() {
m_Items.clear();
m_Buffer.Clear();
m_dwObjNum = 0;
m_index = 0;
}
void CPDF_ObjectStream::CompressIndirectObject(uint32_t dwObjNum,
const CPDF_Object* pObj) {
m_Items.push_back({dwObjNum, m_Buffer.GetLength()});
m_Buffer << pObj;
}
void CPDF_ObjectStream::CompressIndirectObject(uint32_t dwObjNum,
const uint8_t* pBuffer,
uint32_t dwSize) {
m_Items.push_back({dwObjNum, m_Buffer.GetLength()});
m_Buffer.AppendBlock(pBuffer, dwSize);
}
FX_FILESIZE CPDF_ObjectStream::End(CPDF_Creator* pCreator) {
ASSERT(pCreator);
if (m_Items.empty())
return 0;
IFX_ArchiveStream* archive = pCreator->GetArchive();
FX_FILESIZE ObjOffset = archive->CurrentOffset();
if (!m_dwObjNum)
m_dwObjNum = pCreator->GetNextObjectNumber();
CFX_ByteTextBuf tempBuffer;
for (const auto& pair : m_Items)
tempBuffer << pair.objnum << " " << pair.offset << " ";
if (!archive->WriteDWord(m_dwObjNum) ||
!archive->WriteString(" 0 obj\r\n<</Type /ObjStm /N ") ||
!archive->WriteDWord(pdfium::CollectionSize<uint32_t>(m_Items)) ||
!archive->WriteString("/First ") ||
!archive->WriteDWord(static_cast<uint32_t>(tempBuffer.GetLength())) ||
!archive->WriteString("/Length ")) {
return -1;
}
tempBuffer << m_Buffer;
CPDF_FlateEncoder encoder(tempBuffer.GetBuffer(), tempBuffer.GetLength(),
true, false);
CPDF_Encryptor encryptor(pCreator->GetCryptoHandler(), m_dwObjNum,
encoder.GetData(), encoder.GetSize());
if (!archive->WriteDWord(encryptor.GetSize()) ||
!archive->WriteString("/Filter /FlateDecode") ||
!archive->WriteString(">>stream\r\n") ||
!archive->WriteBlock(encryptor.GetData(), encryptor.GetSize()) ||
!archive->WriteString("\r\nendstream\r\nendobj\r\n")) {
return -1;
}
return ObjOffset;
}
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