public int Read(ByteContainer buffer, int offset, int count)
{
Tracing.Log(Tracing.Debug, "Entered");
long currentLength = (long)_info.size;
// just touch the file
if (count == 0 || _pos >= currentLength)
{
return(0);
}
long bytesLeft;
if (currentLength - _pos > (long)count)
{
bytesLeft = (long)count;
}
else
{
bytesLeft = currentLength - _pos;
}
////
//Console.WriteLine("ReadArgs: count = " + args.count +
// " offset = " + args.offset +
// " bytes to be read " + bytesLeft);
//
if (buffer == null)
{
//Console.WriteLine("ReadNFS: user buffer was null!");
throw new ArgumentNullException("Buffer given to Read was null");
}
else if ((long)buffer.Length < bytesLeft)
{
throw new ArgumentException("Not enough room in buffer");
}
long uBufOff = (long)offset; // offset into user's buffer;
long curFileOff = _pos;
long blockno = -1;
while (bytesLeft > 0)
{
long curBlk = _info.BlockFromByte(curFileOff);
long curBlkSize = Iso9660FileInfo.BlockSize(curBlk);
long curBlkOff = curFileOff % curBlkSize;
////
//Console.WriteLine("ReadArgs: curBlockNum " + curBlk +
// " curBlkSize = " + curBlkSize +
// " cur offset into blk " + curBlkOff);
//
if (blockno < curBlk)
{
blockno = curBlk;
//
// 1. fetch data from media's block
//
Iso9660.Stdio.RawDevice.ReadBlock(_info.buf, (ulong)blockno);
}
long dist;
if (curBlkSize - curBlkOff > bytesLeft)
{
dist = bytesLeft;
}
else
{
dist = curBlkSize - curBlkOff;
}
//
// 2. store data into user's buffer
//
buffer.CopyTo(_info.buf, (int)curBlkOff, (int)uBufOff, (int)dist);
uBufOff += dist;
curFileOff += dist;
bytesLeft -= dist;
}
_pos += uBufOff;
return((int)uBufOff);
Tracing.Log(Tracing.Debug, "Exit");
}
public Iso9660FileStream(Iso9660FileInfo info, FileMode mode,
FileAccess access)
{
_info = info;
_pos = 0;
}
