inbyte.cpp

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
*/

#include "inbyte.h"

namespace NStream{

CInByte::CInByte(UINT32 aBufferSize):
  m_BufferBase(0),
  m_BufferSize(aBufferSize)
{
  m_BufferBase = new BYTE[m_BufferSize];
}

CInByte::~CInByte()
{
  delete []m_BufferBase;
}

void CInByte::Init(ISequentialInStream *aStream)
{
  m_Stream = aStream;
  m_ProcessedSize = 0;
  m_Buffer = m_BufferBase;
  m_BufferLimit = m_Buffer;
  m_StreamWasExhausted = false;
}

bool CInByte::ReadBlock()
{
  if (m_StreamWasExhausted)
    return false;
  m_ProcessedSize += (m_Buffer - m_BufferBase);
  UINT32 aNumProcessedBytes;
  HRESULT aResult = m_Stream->Read(m_BufferBase, m_BufferSize, &aNumProcessedBytes);
  if (aResult != S_OK)
    throw aResult;
  m_Buffer = m_BufferBase;
  m_BufferLimit = m_Buffer + aNumProcessedBytes;
  m_StreamWasExhausted = (aNumProcessedBytes == 0);
  return (!m_StreamWasExhausted);
}

}