outbuffer.h

MONA是为数不多的C++语言编写的一个很小的操作系统

// OutBuffer.h

#ifndef __OUTBUFFER_H
#define __OUTBUFFER_H

#include "../IStream.h"
#include "../../Common/MyCom.h"

#ifndef _NO_EXCEPTIONS
struct COutBufferException
{
  HRESULT ErrorCode;
  COutBufferException(HRESULT errorCode): ErrorCode(errorCode) {}
};
#endif

class COutBuffer
{
  Byte *_buffer;
  UInt32 _pos;
  UInt32 _bufferSize;
  CMyComPtr<ISequentialOutStream> _stream;
  UInt64 _processedSize;

  void WriteBlock();
public:
  #ifdef _NO_EXCEPTIONS
  HRESULT ErrorCode;
  #endif

  COutBuffer(): _buffer(0), _pos(0), _stream(0) {}
  ~COutBuffer() { Free(); }
  
  bool Create(UInt32 bufferSize);
  void Free();

  void SetStream(ISequentialOutStream *stream);
  void Init();
  HRESULT Flush();
  void ReleaseStream() {  _stream.Release(); }

  /*
  void *GetBuffer(UInt32 &sizeAvail)
  {
    sizeAvail = _bufferSize - _pos;
    return _buffer + _pos;
  }
  void MovePos(UInt32 num)
  {
    _pos += num;
    if(_pos >= _bufferSize)
      WriteBlock();
  }
  */

  void WriteByte(Byte b)
  {
    _buffer[_pos++] = b;
    if(_pos >= _bufferSize)
      WriteBlock();
  }
  void WriteBytes(const void *data, UInt32 size)
  {
    for (UInt32 i = 0; i < size; i++)
      WriteByte(((const Byte *)data)[i]);
  }

  UInt64 GetProcessedSize() const { return _processedSize + _pos; }
};

#endif