public ReadBufferState(
byte[] buffer, int offset, int count, HttpStreamAsyncResult asyncResult)
{
_buffer = buffer;
_offset = offset;
_count = count;
_initialCount = count;
_asyncResult = asyncResult;
}
public override IAsyncResult BeginRead(
byte[] buffer, int offset, int count, AsyncCallback callback, object state)
{
if (_disposed)
{
throw new ObjectDisposedException(GetType().ToString());
}
if (buffer == null)
{
throw new ArgumentNullException("buffer");
}
if (offset < 0)
{
throw new ArgumentOutOfRangeException("offset", "A negative value.");
}
if (count < 0)
{
throw new ArgumentOutOfRangeException("count", "A negative value.");
}
var len = buffer.Length;
if (offset + count > len)
{
throw new ArgumentException(
"The sum of 'offset' and 'count' is greater than 'buffer' length.");
}
var ares = new HttpStreamAsyncResult(callback, state);
if (_noMoreData)
{
ares.Complete();
return(ares);
}
var nread = _decoder.Read(buffer, offset, count);
offset += nread;
count -= nread;
if (count == 0)
{
// Got all we wanted, no need to bother the decoder yet.
ares.Count = nread;
ares.Complete();
return(ares);
}
if (!_decoder.WantMore)
{
_noMoreData = nread == 0;
ares.Count = nread;
ares.Complete();
return(ares);
}
ares.Buffer = new byte[_bufferLength];
ares.Offset = 0;
ares.Count = _bufferLength;
var rstate = new ReadBufferState(buffer, offset, count, ares);
rstate.InitialCount += nread;
base.BeginRead(ares.Buffer, ares.Offset, ares.Count, onRead, rstate);
return(ares);
}