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.ReadMessage(DataRowLoadingMode.NonSequential);
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 (_readBuf.ReadBytesLeft == 0)
{
_readBuf.ReadMore();
}
Contract.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);
}
internal override T2 ReadFully <T2>(ReadBuffer buf, int len, FieldDescription fieldDescription = null)
{
var asTypedHandler = this as IChunkingTypeHandler <T2>;
if (asTypedHandler == null)
{
throw new InvalidCastException(fieldDescription == null
? "Can't cast database type to " + typeof(T2).Name
: $"Can't cast database type {fieldDescription.Handler.PgDisplayName} to {typeof(T2).Name}"
);
}
asTypedHandler.PrepareRead(buf, len, fieldDescription);
T2 result;
while (!asTypedHandler.Read(out result))
{
buf.ReadMore();
}
return(result);
}
