lzoutwindow.h

压缩软件源码

// LZOutWindow.h

#ifndef __LZ_OUT_WINDOW_H
#define __LZ_OUT_WINDOW_H

#include "../../IStream.h"

#ifndef _NO_EXCEPTIONS
class CLZOutWindowException
{
public:
  HRESULT ErrorCode;
  CLZOutWindowException(HRESULT errorCode): ErrorCode(errorCode) {}
};
#endif

class CLZOutWindow
{
  Byte  *_buffer;
  UInt32 _pos;
  UInt32 _windowSize;
  UInt32 _streamPos;
  ISequentialOutStream *_stream;
  void FlushWithCheck();
public:
  #ifdef _NO_EXCEPTIONS
  HRESULT ErrorCode;
  #endif

  void Free();
  CLZOutWindow(): _buffer(0), _stream(0) {}
  ~CLZOutWindow() { Free();  ReleaseStream(); }
  bool Create(UInt32 windowSize);
  
  void SetStream(ISequentialOutStream *stream);
  void Init(bool solid = false);
  HRESULT Flush();
  void ReleaseStream();
  
  void CopyBlock(UInt32 distance, UInt32 len)
  {
    UInt32 pos = _pos - distance - 1;
    if (pos >= _windowSize)
      pos += _windowSize;
    for(; len > 0; len--)
    {
      if (pos >= _windowSize)
        pos = 0;
      _buffer[_pos++] = _buffer[pos++];
      if (_pos >= _windowSize)
        FlushWithCheck();  
      // PutOneByte(GetOneByte(distance));
    }
  }
  
  void PutByte(Byte b)
  {
    _buffer[_pos++] = b;
    if (_pos >= _windowSize)
      FlushWithCheck();  
  }
  
  Byte GetByte(UInt32 distance) const
  {
    UInt32 pos = _pos - distance - 1;
    if (pos >= _windowSize)
      pos += _windowSize;
    return _buffer[pos]; 
  }
};

#endif