text: // Copyright 2016 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/parser/cpdf_stream.h"
  
  #include "core/fpdfapi/parser/cpdf_dictionary.h"
  #include "core/fpdfapi/parser/cpdf_stream_acc.h"
  #include "core/fpdfapi/parser/fpdf_parser_decode.h"
  #include "third_party/base/numerics/safe_conversions.h"
  #include "third_party/base/stl_util.h"
  
  CPDF_Stream::CPDF_Stream() {}
  
  CPDF_Stream::CPDF_Stream(uint8_t* pData, uint32_t size, CPDF_Dictionary* pDict)
      : m_pDict(pDict), m_dwSize(size), m_pDataBuf(pData) {}
  
  CPDF_Stream::~CPDF_Stream() {
    m_ObjNum = kInvalidObjNum;
    if (m_pDict && m_pDict->GetObjNum() == kInvalidObjNum)
      m_pDict.release();  // lowercase release, release ownership.
  }
  
  CPDF_Object::Type CPDF_Stream::GetType() const {
    return STREAM;
  }
  
  CPDF_Dictionary* CPDF_Stream::GetDict() const {
    return m_pDict.get();
  }
  
  bool CPDF_Stream::IsStream() const {
    return true;
  }
  
  CPDF_Stream* CPDF_Stream::AsStream() {
    return this;
  }
  
  const CPDF_Stream* CPDF_Stream::AsStream() const {
    return this;
  }
  
  void CPDF_Stream::InitStream(const uint8_t* pData,
                               uint32_t size,
                               CPDF_Dictionary* pDict) {
    m_pDict.reset(pDict);
    m_bMemoryBased = true;
    m_pFile = nullptr;
    m_pDataBuf.reset(FX_Alloc(uint8_t, size));
    if (pData)
      FXSYS_memcpy(m_pDataBuf.get(), pData, size);
    m_dwSize = size;
    if (m_pDict)
      m_pDict->SetIntegerFor("Length", m_dwSize);
  }
  
  void CPDF_Stream::InitStreamFromFile(IFX_FileRead* pFile,
                                       CPDF_Dictionary* pDict) {
    m_pDict.reset(pDict);
    m_bMemoryBased = false;
    m_pDataBuf.reset();
    m_pFile = pFile;
    m_dwSize = pdfium::base::checked_cast<uint32_t>(pFile->GetSize());
    if (m_pDict)
      m_pDict->SetIntegerFor("Length", m_dwSize);
  }
  
  CPDF_Object* CPDF_Stream::Clone() const {
    return CloneObjectNonCyclic(false);
  }
  
  CPDF_Object* CPDF_Stream::CloneNonCyclic(
      bool bDirect,
      std::set<const CPDF_Object*>* pVisited) const {
    pVisited->insert(this);
    CPDF_StreamAcc acc;
    acc.LoadAllData(this, TRUE);
    uint32_t streamSize = acc.GetSize();
    CPDF_Dictionary* pDict = GetDict();
    if (pDict && !pdfium::ContainsKey(*pVisited, pDict)) {
      pDict = ToDictionary(
          static_cast<CPDF_Object*>(pDict)->CloneNonCyclic(bDirect, pVisited));
    }
  
    return new CPDF_Stream(acc.DetachData(), streamSize, pDict);
  }
  
  void CPDF_Stream::SetData(const uint8_t* pData, uint32_t size) {
    m_bMemoryBased = true;
    m_pDataBuf.reset(FX_Alloc(uint8_t, size));
    if (pData)
      FXSYS_memcpy(m_pDataBuf.get(), pData, size);
    m_dwSize = size;
    if (!m_pDict)
      m_pDict.reset(new CPDF_Dictionary());
    m_pDict->SetIntegerFor("Length", size);
    m_pDict->RemoveFor("Filter");
    m_pDict->RemoveFor("DecodeParms");
  }
  
  FX_BOOL CPDF_Stream::ReadRawData(FX_FILESIZE offset,
                                   uint8_t* buf,
                                   uint32_t size) const {
    if (m_bMemoryBased && m_pFile)
      return m_pFile->ReadBlock(buf, offset, size);
  
    if (m_pDataBuf)
      FXSYS_memcpy(buf, m_pDataBuf.get() + offset, size);
  
    return TRUE;
  }
  
  CFX_WideString CPDF_Stream::GetUnicodeText() const {
    CPDF_StreamAcc stream;
    stream.LoadAllData(this, FALSE);
    return PDF_DecodeText(stream.GetData(), stream.GetSize());
  }
  