public override int Read(byte[] buffer, int offset, int count)
{
CheckDisposed();
if (!CanRead)
{
throw new InvalidOperationException("Stream not open for reading");
}
if (_isConsumed)
{
return(0);
}
if (_leftToReadInDataMsg == 0)
{
// We've consumed the current DataMessage (or haven't yet received the first),
// read the next message
var msg = _connector.ReadSingleMessage();
switch (msg.Code)
{
case BackendMessageCode.CopyData:
_leftToReadInDataMsg = ((CopyDataMessage)msg).Length;
break;
case BackendMessageCode.CopyDone:
_connector.ReadExpecting <CommandCompleteMessage>();
_connector.ReadExpecting <ReadyForQueryMessage>();
_isConsumed = true;
return(0);
default:
throw _connector.UnexpectedMessageReceived(msg.Code);
}
}
Contract.Assume(_leftToReadInDataMsg > 0);
// If our buffer is empty, read in more. Otherwise return whatever is there, even if the
// user asked for more (normal socket behavior)
if (_buf.ReadBytesLeft == 0)
{
_buf.ReadMore();
}
Contract.Assert(_buf.ReadBytesLeft > 0);
var maxCount = Math.Min(_buf.ReadBytesLeft, _leftToReadInDataMsg);
if (count > maxCount)
{
count = maxCount;
}
_leftToReadInDataMsg -= count;
_buf.ReadBytes(buffer, offset, count);
return(count);
}