Rename IFGAS_Stream to CFGAS_Stream

This CL replaces IFGAS_Stream with the only implementation CFGAS_Stream.
The CreateReadStream and CreateWriteStream methods are removed in favour
of calling MakeRetain directly.

Change-Id: I882a89258f642e24fc3d631587db05652bd53ded
Reviewed-on: https://pdfium-review.googlesource.com/4210
Commit-Queue: dsinclair <dsinclair@chromium.org>
Reviewed-by: Nicolás Peña <npm@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>

1 files changed, 0 insertions, 357 deletions

diff --git a/xfa/fgas/crt/ifgas_stream.cpp b/xfa/fgas/crt/ifgas_stream.cpp
deleted file mode 100644
index 7a90626fe8..0000000000
--- a/xfa/fgas/crt/ifgas_stream.cpp
+++ /dev/null
@@ -1,357 +0,0 @@
-// Copyright 2014 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 "xfa/fgas/crt/ifgas_stream.h"
-
-#if _FX_OS_ == _FX_WIN32_DESKTOP_ || _FX_OS_ == _FX_WIN32_MOBILE_ || \
-    _FX_OS_ == _FX_WIN64_
-#include <io.h>
-#endif
-
-#include <algorithm>
-#include <memory>
-#include <utility>
-#include <vector>
-
-#include "core/fxcrt/fx_ext.h"
-#include "third_party/base/ptr_util.h"
-#include "third_party/base/stl_util.h"
-#include "xfa/fgas/crt/fgas_codepage.h"
-
-namespace {
-
-class CFGAS_Stream : public IFGAS_Stream {
- public:
-  template <typename T, typename... Args>
-  friend CFX_RetainPtr<T> pdfium::MakeRetain(Args&&... args);
-
-  // IFGAS_Stream
-  FX_FILESIZE GetLength() const override { return m_pStream->GetSize(); }
-  FX_FILESIZE GetPosition() override { return m_iPosition; }
-  FX_STRSIZE GetBOMLength() const override { return std::max(0, m_wBOMLength); }
-  FX_STRSIZE ReadString(wchar_t* pStr,
-                        FX_STRSIZE iMaxLength,
-                        bool* bEOS) override;
-  void Seek(FX_STREAMSEEK eSeek, FX_FILESIZE iOffset) override;
-  bool IsEOF() const override { return m_iPosition >= GetLength(); }
-  void WriteString(const CFX_WideStringC& str) override;
-  uint16_t GetCodePage() const override { return m_wCodePage; }
-  void SetCodePage(uint16_t wCodePage) override;
-
- private:
-  CFGAS_Stream(const CFX_RetainPtr<IFX_SeekableStream>& stream,
-               bool isWriteSteam);
-  ~CFGAS_Stream() override;
-
-  FX_STRSIZE ReadData(uint8_t* pBuffer, FX_STRSIZE iBufferSize);
-  void WriteData(const CFX_WideStringC& str);
-
-  uint16_t m_wCodePage;
-  FX_STRSIZE m_wBOMLength;
-  bool m_IsWriteStream;
-  FX_FILESIZE m_iPosition;
-  CFX_RetainPtr<IFX_SeekableStream> m_pStream;
-};
-
-// Returns {src bytes consumed, dst bytes produced}.
-std::pair<FX_STRSIZE, FX_STRSIZE> UTF8Decode(const char* pSrc,
-                                             FX_STRSIZE srcLen,
-                                             wchar_t* pDst,
-                                             FX_STRSIZE dstLen) {
-  ASSERT(pDst && dstLen > 0);
-
-  if (srcLen < 1)
-    return {0, 0};
-
-  uint32_t dwCode = 0;
-  int32_t iPending = 0;
-  FX_STRSIZE iSrcNum = 0;
-  FX_STRSIZE iDstNum = 0;
-  FX_STRSIZE iIndex = 0;
-  int32_t k = 1;
-  while (iIndex < srcLen) {
-    uint8_t byte = static_cast<uint8_t>(*(pSrc + iIndex));
-    if (byte < 0x80) {
-      iPending = 0;
-      k = 1;
-      iDstNum++;
-      iSrcNum += k;
-      *pDst++ = byte;
-      if (iDstNum >= dstLen)
-        break;
-    } else if (byte < 0xc0) {
-      if (iPending < 1)
-        break;
-
-      iPending--;
-      dwCode |= (byte & 0x3f) << (iPending * 6);
-      if (iPending == 0) {
-        iDstNum++;
-        iSrcNum += k;
-        *pDst++ = dwCode;
-        if (iDstNum >= dstLen)
-          break;
-      }
-    } else if (byte < 0xe0) {
-      iPending = 1;
-      k = 2;
-      dwCode = (byte & 0x1f) << 6;
-    } else if (byte < 0xf0) {
-      iPending = 2;
-      k = 3;
-      dwCode = (byte & 0x0f) << 12;
-    } else if (byte < 0xf8) {
-      iPending = 3;
-      k = 4;
-      dwCode = (byte & 0x07) << 18;
-    } else if (byte < 0xfc) {
-      iPending = 4;
-      k = 5;
-      dwCode = (byte & 0x03) << 24;
-    } else if (byte < 0xfe) {
-      iPending = 5;
-      k = 6;
-      dwCode = (byte & 0x01) << 30;
-    } else {
-      break;
-    }
-    iIndex++;
-  }
-  return {iSrcNum, iDstNum};
-}
-
-void UTF16ToWChar(void* pBuffer, FX_STRSIZE iLength) {
-  ASSERT(pBuffer && iLength > 0);
-
-  if (sizeof(wchar_t) == 2)
-    return;
-
-  uint16_t* pSrc = static_cast<uint16_t*>(pBuffer);
-  wchar_t* pDst = static_cast<wchar_t*>(pBuffer);
-  while (--iLength >= 0)
-    pDst[iLength] = static_cast<wchar_t>(pSrc[iLength]);
-}
-
-void SwapByteOrder(wchar_t* pStr, FX_STRSIZE iLength) {
-  ASSERT(pStr);
-
-  if (iLength < 0)
-    iLength = FXSYS_wcslen(pStr);
-
-  uint16_t wch;
-  if (sizeof(wchar_t) > 2) {
-    while (iLength-- > 0) {
-      wch = static_cast<uint16_t>(*pStr);
-      wch = (wch >> 8) | (wch << 8);
-      wch &= 0x00FF;
-      *pStr = wch;
-      ++pStr;
-    }
-    return;
-  }
-
-  while (iLength-- > 0) {
-    wch = static_cast<uint16_t>(*pStr);
-    wch = (wch >> 8) | (wch << 8);
-    *pStr = wch;
-    ++pStr;
-  }
-}
-
-#if _FX_ENDIAN_ == _FX_LITTLE_ENDIAN_
-#define BOM_MASK 0x00FFFFFF
-#define BOM_UTF8 0x00BFBBEF
-#define BOM_UTF16_MASK 0x0000FFFF
-#define BOM_UTF16_BE 0x0000FFFE
-#define BOM_UTF16_LE 0x0000FEFF
-#else
-#define BOM_MASK 0xFFFFFF00
-#define BOM_UTF8 0xEFBBBF00
-#define BOM_UTF16_MASK 0xFFFF0000
-#define BOM_UTF16_BE 0xFEFF0000
-#define BOM_UTF16_LE 0xFFFE0000
-#endif  // _FX_ENDIAN_ == _FX_LITTLE_ENDIAN_
-
-CFGAS_Stream::CFGAS_Stream(const CFX_RetainPtr<IFX_SeekableStream>& stream,
-                           bool isWriteStream)
-    : m_wCodePage(FX_CODEPAGE_DefANSI),
-      m_wBOMLength(0),
-      m_IsWriteStream(isWriteStream),
-      m_iPosition(0),
-      m_pStream(stream) {
-  ASSERT(m_pStream);
-
-  if (isWriteStream) {
-    m_iPosition = m_pStream->GetSize();
-    return;
-  }
-
-  FX_FILESIZE iPosition = GetPosition();
-  Seek(FX_STREAMSEEK_Begin, 0);
-
-  uint32_t bom;
-  ReadData(reinterpret_cast<uint8_t*>(&bom), 3);
-
-  bom &= BOM_MASK;
-  if (bom == BOM_UTF8) {
-    m_wBOMLength = 3;
-    m_wCodePage = FX_CODEPAGE_UTF8;
-  } else {
-    bom &= BOM_UTF16_MASK;
-    if (bom == BOM_UTF16_BE) {
-      m_wBOMLength = 2;
-      m_wCodePage = FX_CODEPAGE_UTF16BE;
-    } else if (bom == BOM_UTF16_LE) {
-      m_wBOMLength = 2;
-      m_wCodePage = FX_CODEPAGE_UTF16LE;
-    } else {
-      m_wBOMLength = 0;
-      m_wCodePage = FXSYS_GetACP();
-    }
-  }
-
-  Seek(FX_STREAMSEEK_Begin,
-       std::max(static_cast<FX_FILESIZE>(m_wBOMLength), iPosition));
-}
-
-CFGAS_Stream::~CFGAS_Stream() {}
-
-void CFGAS_Stream::Seek(FX_STREAMSEEK eSeek, FX_FILESIZE iOffset) {
-  switch (eSeek) {
-    case FX_STREAMSEEK_Begin:
-      m_iPosition = iOffset;
-      break;
-    case FX_STREAMSEEK_Current:
-      m_iPosition += iOffset;
-      break;
-  }
-  m_iPosition =
-      pdfium::clamp(m_iPosition, static_cast<FX_FILESIZE>(0), GetLength());
-}
-
-void CFGAS_Stream::SetCodePage(uint16_t wCodePage) {
-  if (m_wBOMLength > 0)
-    return;
-  m_wCodePage = wCodePage;
-}
-
-FX_STRSIZE CFGAS_Stream::ReadData(uint8_t* pBuffer, FX_STRSIZE iBufferSize) {
-  ASSERT(pBuffer && iBufferSize > 0);
-
-  if (m_IsWriteStream)
-    return -1;
-
-  iBufferSize = std::min(
-      iBufferSize, static_cast<FX_STRSIZE>(m_pStream->GetSize() - m_iPosition));
-  if (iBufferSize <= 0)
-    return 0;
-
-  if (m_pStream->ReadBlock(pBuffer, m_iPosition, iBufferSize)) {
-    pdfium::base::CheckedNumeric<FX_FILESIZE> new_pos = m_iPosition;
-    new_pos += iBufferSize;
-    if (!new_pos.IsValid())
-      return 0;
-
-    m_iPosition = new_pos.ValueOrDie();
-    return iBufferSize;
-  }
-  return 0;
-}
-
-FX_STRSIZE CFGAS_Stream::ReadString(wchar_t* pStr,
-                                    FX_STRSIZE iMaxLength,
-                                    bool* bEOS) {
-  ASSERT(pStr && iMaxLength > 0);
-
-  if (m_IsWriteStream)
-    return -1;
-
-  if (m_wCodePage == FX_CODEPAGE_UTF16LE ||
-      m_wCodePage == FX_CODEPAGE_UTF16BE) {
-    FX_FILESIZE iBytes = iMaxLength * 2;
-    FX_STRSIZE iLen = ReadData(reinterpret_cast<uint8_t*>(pStr), iBytes);
-    iMaxLength = iLen / 2;
-    if (sizeof(wchar_t) > 2)
-      UTF16ToWChar(pStr, iMaxLength);
-
-#if _FX_ENDIAN_ == _FX_BIG_ENDIAN_
-    if (m_wCodePage == FX_CODEPAGE_UTF16LE)
-      SwapByteOrder(pStr, iMaxLength);
-#else
-    if (m_wCodePage == FX_CODEPAGE_UTF16BE)
-      SwapByteOrder(pStr, iMaxLength);
-#endif
-
-  } else {
-    FX_FILESIZE pos = GetPosition();
-    FX_STRSIZE iBytes =
-        std::min(iMaxLength, static_cast<FX_STRSIZE>(GetLength() - pos));
-
-    if (iBytes > 0) {
-      std::vector<uint8_t> buf(iBytes);
-
-      FX_STRSIZE iLen = ReadData(buf.data(), iBytes);
-      if (m_wCodePage != FX_CODEPAGE_UTF8)
-        return -1;
-
-      FX_STRSIZE iSrc = 0;
-      std::tie(iSrc, iMaxLength) = UTF8Decode(
-          reinterpret_cast<const char*>(buf.data()), iLen, pStr, iMaxLength);
-      Seek(FX_STREAMSEEK_Current, iSrc - iLen);
-    } else {
-      iMaxLength = 0;
-    }
-  }
-
-  *bEOS = IsEOF();
-  return iMaxLength;
-}
-
-void CFGAS_Stream::WriteData(const CFX_WideStringC& str) {
-  if (!m_IsWriteStream || str.GetLength() == 0)
-    return;
-  if (m_pStream->WriteBlock(str.c_str(), m_iPosition,
-                            str.GetLength() * sizeof(wchar_t))) {
-    pdfium::base::CheckedNumeric<FX_STRSIZE> new_pos = m_iPosition;
-    new_pos += str.GetLength() * sizeof(wchar_t);
-    // TODO(dsinclair): Not sure what to do if we over flow ....
-    if (!new_pos.IsValid())
-      return;
-
-    m_iPosition = new_pos.ValueOrDie();
-  }
-}
-
-void CFGAS_Stream::WriteString(const CFX_WideStringC& str) {
-  if (!m_IsWriteStream)
-    return;
-  if (str.GetLength() == 0)
-    return;
-  if (m_wCodePage != FX_CODEPAGE_UTF8)
-    return;
-
-  WriteData(str);
-}
-
-}  // namespace
-
-// static
-CFX_RetainPtr<IFGAS_Stream> IFGAS_Stream::CreateReadStream(
-    const CFX_RetainPtr<IFX_SeekableStream>& pFileRead) {
-  if (!pFileRead)
-    return nullptr;
-
-  return pdfium::MakeRetain<CFGAS_Stream>(pFileRead, false);
-}
-
-// static
-CFX_RetainPtr<IFGAS_Stream> IFGAS_Stream::CreateWriteStream(
-    const CFX_RetainPtr<IFX_SeekableStream>& pFileWrite) {
-  if (!pFileWrite)
-    return nullptr;
-
-  return pdfium::MakeRetain<CFGAS_Stream>(pFileWrite, true);
-}