diff options
Diffstat (limited to 'core/fpdfapi/edit/cpdf_xrefstream.cpp')
| -rw-r--r-- | core/fpdfapi/edit/cpdf_xrefstream.cpp | 412 |
1 files changed, 412 insertions, 0 deletions
diff --git a/core/fpdfapi/edit/cpdf_xrefstream.cpp b/core/fpdfapi/edit/cpdf_xrefstream.cpp new file mode 100644 index 0000000000..9ec27f291c --- /dev/null +++ b/core/fpdfapi/edit/cpdf_xrefstream.cpp @@ -0,0 +1,412 @@ +// 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_xrefstream.h" + +#include "core/fpdfapi/edit/cpdf_creator.h" +#include "core/fpdfapi/edit/cpdf_flateencoder.h" +#include "core/fpdfapi/parser/cpdf_array.h" +#include "core/fpdfapi/parser/cpdf_document.h" +#include "core/fpdfapi/parser/cpdf_parser.h" +#include "core/fpdfapi/parser/fpdf_parser_decode.h" + +namespace { + +int32_t WriteTrailer(CPDF_Document* pDocument, + CFX_FileBufferArchive* pFile, + CPDF_Array* pIDArray) { + FX_FILESIZE offset = 0; + int32_t len = 0; + CPDF_Parser* pParser = pDocument->GetParser(); + if (pParser) { + CPDF_Dictionary* p = pParser->GetTrailer(); + for (const auto& it : *p) { + const CFX_ByteString& key = it.first; + CPDF_Object* pValue = it.second.get(); + if (key == "Encrypt" || key == "Size" || key == "Filter" || + key == "Index" || key == "Length" || key == "Prev" || key == "W" || + key == "XRefStm" || key == "Type" || key == "ID") { + continue; + } + if (key == "DecodeParms") + continue; + if (pFile->AppendString(("/")) < 0) + return -1; + if ((len = pFile->AppendString(PDF_NameEncode(key).AsStringC())) < 0) + return -1; + + offset += len + 1; + if (!pValue->IsInline()) { + if (pFile->AppendString(" ") < 0) + return -1; + if ((len = pFile->AppendDWord(pValue->GetObjNum())) < 0) + return -1; + if (pFile->AppendString(" 0 R ") < 0) + return -1; + + offset += len + 6; + } else { + if (!pValue->WriteTo(pFile, &offset)) + return -1; + } + } + if (pIDArray) { + if (pFile->AppendString(("/ID")) < 0) + return -1; + + offset += 3; + if (!pIDArray->WriteTo(pFile, &offset)) + return -1; + } + return offset; + } + if (pFile->AppendString("\r\n/Root ") < 0) + return -1; + if ((len = pFile->AppendDWord(pDocument->GetRoot()->GetObjNum())) < 0) + return -1; + if (pFile->AppendString(" 0 R\r\n") < 0) + return -1; + + offset += len + 14; + if (pDocument->GetInfo()) { + if (pFile->AppendString("/Info ") < 0) + return -1; + if ((len = pFile->AppendDWord(pDocument->GetInfo()->GetObjNum())) < 0) + return -1; + if (pFile->AppendString(" 0 R\r\n") < 0) + return -1; + + offset += len + 12; + } + if (pIDArray) { + if (pFile->AppendString(("/ID")) < 0) + return -1; + + offset += 3; + if (!pIDArray->WriteTo(pFile, &offset)) + return -1; + } + return offset; +} + +int32_t WriteEncryptDictObjectReference(uint32_t dwObjNum, + CFX_FileBufferArchive* pFile) { + ASSERT(pFile); + + FX_FILESIZE offset = 0; + int32_t len = 0; + if (pFile->AppendString("/Encrypt") < 0) + return -1; + + offset += 8; + if (pFile->AppendString(" ") < 0) + return -1; + if ((len = pFile->AppendDWord(dwObjNum)) < 0) + return -1; + if (pFile->AppendString(" 0 R ") < 0) + return -1; + + offset += len + 6; + return offset; +} + +void AppendIndex0(CFX_ByteTextBuf& buffer, bool bFirstObject) { + buffer.AppendByte(0); + buffer.AppendByte(0); + buffer.AppendByte(0); + buffer.AppendByte(0); + buffer.AppendByte(0); + + const uint8_t byte = bFirstObject ? 0xFF : 0; + buffer.AppendByte(byte); + buffer.AppendByte(byte); +} + +void AppendIndex1(CFX_ByteTextBuf& buffer, FX_FILESIZE offset) { + buffer.AppendByte(1); + buffer.AppendByte(static_cast<uint8_t>(offset >> 24)); + buffer.AppendByte(static_cast<uint8_t>(offset >> 16)); + buffer.AppendByte(static_cast<uint8_t>(offset >> 8)); + buffer.AppendByte(static_cast<uint8_t>(offset)); + buffer.AppendByte(0); + buffer.AppendByte(0); +} + +void AppendIndex2(CFX_ByteTextBuf& buffer, uint32_t objnum, int32_t index) { + buffer.AppendByte(2); + buffer.AppendByte(static_cast<uint8_t>(objnum >> 24)); + buffer.AppendByte(static_cast<uint8_t>(objnum >> 16)); + buffer.AppendByte(static_cast<uint8_t>(objnum >> 8)); + buffer.AppendByte(static_cast<uint8_t>(objnum)); + buffer.AppendByte(static_cast<uint8_t>(index >> 8)); + buffer.AppendByte(static_cast<uint8_t>(index)); +} + +} // namespace + +CPDF_XRefStream::CPDF_XRefStream() + : m_PrevOffset(0), m_dwTempObjNum(0), m_iSeg(0) {} + +CPDF_XRefStream::~CPDF_XRefStream() {} + +bool CPDF_XRefStream::Start() { + m_IndexArray.clear(); + m_Buffer.Clear(); + m_iSeg = 0; + return true; +} + +int32_t CPDF_XRefStream::CompressIndirectObject(uint32_t dwObjNum, + const CPDF_Object* pObj, + CPDF_Creator* pCreator) { + ASSERT(pCreator); + + m_ObjStream.CompressIndirectObject(dwObjNum, pObj); + if (m_ObjStream.ItemCount() < pCreator->GetObjectStreamSize() && + m_ObjStream.IsNotFull()) { + return 1; + } + return EndObjectStream(pCreator, true); +} + +int32_t CPDF_XRefStream::CompressIndirectObject(uint32_t dwObjNum, + const uint8_t* pBuffer, + uint32_t dwSize, + CPDF_Creator* pCreator) { + ASSERT(pCreator); + + m_ObjStream.CompressIndirectObject(dwObjNum, pBuffer, dwSize); + if (m_ObjStream.ItemCount() < pCreator->GetObjectStreamSize() && + m_ObjStream.IsNotFull()) { + return 1; + } + return EndObjectStream(pCreator, true); +} + +int32_t CPDF_XRefStream::EndObjectStream(CPDF_Creator* pCreator, bool bEOF) { + FX_FILESIZE objOffset = 0; + if (bEOF) { + objOffset = m_ObjStream.End(pCreator); + if (objOffset < 0) + return -1; + } + + if (!m_ObjStream.GetObjectNumber()) + m_ObjStream.SetObjectNumber(pCreator->GetNextObjectNumber()); + + int32_t iSize = m_ObjStream.ItemCount(); + size_t iSeg = m_IndexArray.size(); + if (!pCreator->IsIncremental()) { + if (m_dwTempObjNum == 0) { + AppendIndex0(m_Buffer, true); + m_dwTempObjNum++; + } + uint32_t end_num = m_IndexArray.back().objnum + m_IndexArray.back().count; + int index = 0; + for (; m_dwTempObjNum < end_num; m_dwTempObjNum++) { + if (pCreator->HasObjectNumber(m_dwTempObjNum)) { + if (index >= iSize || + m_dwTempObjNum != m_ObjStream.GetObjectNumberForItem(index)) { + AppendIndex1(m_Buffer, pCreator->GetObjectOffset(m_dwTempObjNum)); + } else { + AppendIndex2(m_Buffer, m_ObjStream.GetObjectNumber(), index++); + } + } else { + AppendIndex0(m_Buffer, false); + } + } + if (iSize > 0 && bEOF) + pCreator->SetObjectOffset(m_ObjStream.GetObjectNumber(), objOffset); + + m_iSeg = iSeg; + if (bEOF) + m_ObjStream.Start(); + + return 1; + } + for (auto it = m_IndexArray.begin() + m_iSeg; it != m_IndexArray.end(); + ++it) { + for (uint32_t m = it->objnum; m < it->objnum + it->count; ++m) { + if (m_ObjStream.GetIndex() >= iSize || + m != m_ObjStream.GetObjectNumberForItem(it - m_IndexArray.begin())) { + AppendIndex1(m_Buffer, pCreator->GetObjectOffset(m)); + } else { + AppendIndex2(m_Buffer, m_ObjStream.GetObjectNumber(), + m_ObjStream.GetIndex()); + m_ObjStream.IncrementIndex(); + } + } + } + if (iSize > 0 && bEOF) { + AppendIndex1(m_Buffer, objOffset); + m_IndexArray.push_back({m_ObjStream.GetObjectNumber(), 1}); + iSeg += 1; + } + m_iSeg = iSeg; + if (bEOF) + m_ObjStream.Start(); + + return 1; +} + +bool CPDF_XRefStream::GenerateXRefStream(CPDF_Creator* pCreator, bool bEOF) { + FX_FILESIZE offset_tmp = pCreator->GetOffset(); + uint32_t objnum = pCreator->GetNextObjectNumber(); + CFX_FileBufferArchive* pFile = pCreator->GetFile(); + if (pCreator->IsIncremental()) { + AddObjectNumberToIndexArray(objnum); + } else { + for (; m_dwTempObjNum < pCreator->GetLastObjectNumber(); m_dwTempObjNum++) { + if (pCreator->HasObjectNumber(m_dwTempObjNum)) + AppendIndex1(m_Buffer, pCreator->GetObjectOffset(m_dwTempObjNum)); + else + AppendIndex0(m_Buffer, false); + } + } + + AppendIndex1(m_Buffer, offset_tmp); + + int32_t len = pFile->AppendDWord(objnum); + if (len < 0) + return false; + + pCreator->IncrementOffset(len); + if ((len = pFile->AppendString(" 0 obj\r\n<</Type /XRef/W[1 4 2]/Index[")) < + 0) { + return false; + } + pCreator->IncrementOffset(len); + if (!pCreator->IsIncremental()) { + if ((len = pFile->AppendDWord(0)) < 0) + return false; + if ((len = pFile->AppendString(" ")) < 0) + return false; + + pCreator->IncrementOffset(len + 1); + if ((len = pFile->AppendDWord(objnum + 1)) < 0) + return false; + + pCreator->IncrementOffset(len); + } else { + for (const auto& pair : m_IndexArray) { + if ((len = pFile->AppendDWord(pair.objnum)) < 0) + return false; + if (pFile->AppendString(" ") < 0) + return false; + + pCreator->IncrementOffset(len + 1); + if ((len = pFile->AppendDWord(pair.count)) < 0) + return false; + if (pFile->AppendString(" ") < 0) + return false; + + pCreator->IncrementOffset(len + 1); + } + } + if (pFile->AppendString("]/Size ") < 0) + return false; + if ((len = pFile->AppendDWord(objnum + 1)) < 0) + return false; + + pCreator->IncrementOffset(len + 7); + if (m_PrevOffset > 0) { + if (pFile->AppendString("/Prev ") < 0) + return false; + + char offset_buf[20]; + memset(offset_buf, 0, sizeof(offset_buf)); + FXSYS_i64toa(m_PrevOffset, offset_buf, 10); + int32_t offset_len = (int32_t)FXSYS_strlen(offset_buf); + if (pFile->AppendBlock(offset_buf, offset_len) < 0) + return false; + + pCreator->IncrementOffset(offset_len + 6); + } + + CPDF_FlateEncoder encoder(m_Buffer.GetBuffer(), m_Buffer.GetLength(), true, + true); + if (pFile->AppendString("/Filter /FlateDecode") < 0) + return false; + + pCreator->IncrementOffset(20); + if ((len = pFile->AppendString("/DecodeParms<</Columns 7/Predictor 12>>")) < + 0) { + return false; + } + + pCreator->IncrementOffset(len); + if (pFile->AppendString("/Length ") < 0) + return false; + if ((len = pFile->AppendDWord(encoder.GetSize())) < 0) + return false; + + pCreator->IncrementOffset(len + 8); + if (bEOF) { + if ((len = WriteTrailer(pCreator->GetDocument(), pFile, + pCreator->GetIDArray())) < 0) { + return false; + } + pCreator->IncrementOffset(len); + + if (CPDF_Dictionary* encryptDict = pCreator->GetEncryptDict()) { + uint32_t dwEncryptObjNum = encryptDict->GetObjNum(); + if (dwEncryptObjNum == 0) + dwEncryptObjNum = pCreator->GetEncryptObjectNumber(); + if ((len = WriteEncryptDictObjectReference(dwEncryptObjNum, pFile)) < 0) + return false; + pCreator->IncrementOffset(len); + } + } + if ((len = pFile->AppendString(">>stream\r\n")) < 0) + return false; + + pCreator->IncrementOffset(len); + if (pFile->AppendBlock(encoder.GetData(), encoder.GetSize()) < 0) + return false; + if ((len = pFile->AppendString("\r\nendstream\r\nendobj\r\n")) < 0) + return false; + + pCreator->IncrementOffset(encoder.GetSize() + len); + m_PrevOffset = offset_tmp; + return true; +} + +bool CPDF_XRefStream::End(CPDF_Creator* pCreator, bool bEOF) { + if (EndObjectStream(pCreator, bEOF) < 0) + return false; + return GenerateXRefStream(pCreator, bEOF); +} + +bool CPDF_XRefStream::EndXRefStream(CPDF_Creator* pCreator) { + if (!pCreator->IsIncremental()) { + AppendIndex0(m_Buffer, true); + for (uint32_t i = 1; i < pCreator->GetLastObjectNumber() + 1; i++) { + if (pCreator->HasObjectNumber(i)) + AppendIndex1(m_Buffer, pCreator->GetObjectOffset(i)); + else + AppendIndex0(m_Buffer, false); + } + } else { + for (const auto& pair : m_IndexArray) { + for (uint32_t j = pair.objnum; j < pair.objnum + pair.count; ++j) + AppendIndex1(m_Buffer, pCreator->GetObjectOffset(j)); + } + } + return GenerateXRefStream(pCreator, false); +} + +void CPDF_XRefStream::AddObjectNumberToIndexArray(uint32_t objnum) { + if (m_IndexArray.empty()) { + m_IndexArray.push_back({objnum, 1}); + return; + } + + uint32_t next_objnum = m_IndexArray.back().objnum + m_IndexArray.back().count; + if (objnum == next_objnum) + m_IndexArray.back().count += 1; + else + m_IndexArray.push_back({objnum, 1}); +} |