inbyte.h

SFC游戏模拟器 snes9x 1.43 的原代码

/*
Copyright (C) 2002 Andrea Mazzoleni ( http://advancemame.sf.net )
Copyright (C) 2001-4 Igor Pavlov ( http://www.7-zip.org )

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

#ifndef __STREAM_INBYTE_H
#define __STREAM_INBYTE_H

#include "iiostrm.h"

namespace NStream {

class CInByte
{
  UINT64 m_ProcessedSize;
  BYTE *m_BufferBase;
  UINT32 m_BufferSize;
  BYTE *m_Buffer;
  BYTE *m_BufferLimit;
  ISequentialInStream* m_Stream;
  bool m_StreamWasExhausted;

  bool ReadBlock();

public:
  CInByte(UINT32 aBufferSize = 0x100000);
  ~CInByte();
  
  void Init(ISequentialInStream *aStream);

  bool ReadByte(BYTE &aByte)
    {
      if(m_Buffer >= m_BufferLimit)
        if(!ReadBlock())
          return false;
      aByte = *m_Buffer++;
      return true;
    }
  BYTE ReadByte()
    {
      if(m_Buffer >= m_BufferLimit)
        if(!ReadBlock())
          return 0x0;
      return *m_Buffer++;
    }
  void ReadBytes(void *aData, UINT32 aSize, UINT32 &aProcessedSize)
    {
      for(aProcessedSize = 0; aProcessedSize < aSize; aProcessedSize++)
        if (!ReadByte(((BYTE *)aData)[aProcessedSize]))
          return;
    }
  bool ReadBytes(void *aData, UINT32 aSize)
    {
      UINT32 aProcessedSize;
      ReadBytes(aData, aSize, aProcessedSize);
      return (aProcessedSize == aSize);
    }
  UINT64 GetProcessedSize() const { return m_ProcessedSize + (m_Buffer - m_BufferBase); }
};

}

#endif