Method ReadRaw

Libraries/unrar/qopen.cpp:235–281

Fill RawRead object from buffer.

// Fill RawRead object from buffer.
bool QuickOpen::ReadRaw(RawRead &Raw)
{
  if (MaxBufSize-ReadBufPos<0x100) // We are close to end of buffer.
  {
    // Ensure that we have enough data to read CRC and header size.
    size_t DataLeft=ReadBufSize-ReadBufPos;
    memcpy(Buf,Buf+ReadBufPos,DataLeft);
    ReadBufPos=0;
    ReadBufSize=DataLeft;
    ReadBuffer();
  }
  const size_t FirstReadSize=7;
  if (ReadBufPos+FirstReadSize>ReadBufSize)
    return false;
  Raw.Read(Buf+ReadBufPos,FirstReadSize);
  ReadBufPos+=FirstReadSize;

  uint SavedCRC=Raw.Get4();
  uint SizeBytes=Raw.GetVSize(4);
  uint64 BlockSize=Raw.GetV();
  int SizeToRead=int(BlockSize);
  SizeToRead-=FirstReadSize-SizeBytes-4; // Adjust overread size bytes if any.
  if (SizeToRead<0 || SizeBytes==0 || BlockSize==0)
  {
    Loaded=false; // Invalid data.
    return false;
  }

  // If rest of block data crosses Buf boundary, read it in loop.
  while (SizeToRead>0)
  {
    size_t DataLeft=ReadBufSize-ReadBufPos;
    size_t CurSizeToRead=Min(DataLeft,(size_t)SizeToRead);
    Raw.Read(Buf+ReadBufPos,CurSizeToRead);
    ReadBufPos+=CurSizeToRead;
    SizeToRead-=int(CurSizeToRead);
    if (SizeToRead>0) // We read the entire buffer and still need more data.
    {
      ReadBufPos=0;
      ReadBufSize=0;
      if (ReadBuffer()==0)
        return false;
    }
  }

  return SavedCRC==Raw.GetCRC50();
}


// Read next cached header.