async ValueTask <int> ReadCore(int count, bool async, CancellationToken cancellationToken = default)
{
if (_isConsumed)
{
return(0);
}
if (_leftToReadInDataMsg == 0)
{
IBackendMessage msg;
try
{
// We've consumed the current DataMessage (or haven't yet received the first),
// read the next message
msg = await _connector.ReadMessage(async, cancellationToken);
}
catch
{
Cleanup();
throw;
}
switch (msg.Code)
{
case BackendMessageCode.CopyData:
_leftToReadInDataMsg = ((CopyDataMessage)msg).Length;
break;
case BackendMessageCode.CopyDone:
Expect <CommandCompleteMessage>(await _connector.ReadMessage(async, cancellationToken), _connector);
Expect <ReadyForQueryMessage>(await _connector.ReadMessage(async, cancellationToken), _connector);
_isConsumed = true;
return(0);
default:
throw _connector.UnexpectedMessageReceived(msg.Code);
}
}
Debug.Assert(_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 (_readBuf.ReadBytesLeft == 0)
{
await _readBuf.ReadMore(async, cancellationToken);
}
Debug.Assert(_readBuf.ReadBytesLeft > 0);
var maxCount = Math.Min(_readBuf.ReadBytesLeft, _leftToReadInDataMsg);
if (count > maxCount)
{
count = maxCount;
}
_leftToReadInDataMsg -= count;
return(count);
}
async Task <int> Read(byte[] buffer, int offset, int count, bool async)
{
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 = await _connector.ReadMessage(async);
switch (msg.Code)
{
case BackendMessageCode.CopyData:
_leftToReadInDataMsg = ((CopyDataMessage)msg).Length;
break;
case BackendMessageCode.CopyDone:
Expect <CommandCompleteMessage>(await _connector.ReadMessage(async), _connector);
Expect <ReadyForQueryMessage>(await _connector.ReadMessage(async), _connector);
_isConsumed = true;
return(0);
default:
throw _connector.UnexpectedMessageReceived(msg.Code);
}
}
Debug.Assert(_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 (_readBuf.ReadBytesLeft == 0)
{
await _readBuf.ReadMore(async);
}
Debug.Assert(_readBuf.ReadBytesLeft > 0);
var maxCount = Math.Min(_readBuf.ReadBytesLeft, _leftToReadInDataMsg);
if (count > maxCount)
{
count = maxCount;
}
_leftToReadInDataMsg -= count;
_readBuf.ReadBytes(buffer, offset, count);
return(count);
}
