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();
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);
}
}
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)
{
_readBuf.ReadMore(false).GetAwaiter().GetResult();
}
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);
}
internal NpgsqlRawCopyStream(NpgsqlConnector connector, string copyCommand)
{
_connector = connector;
_readBuf = connector.ReadBuffer;
_writeBuf = connector.WriteBuffer;
_connector.SendQuery(copyCommand);
var msg = _connector.ReadMessage();
switch (msg.Code)
{
case BackendMessageCode.CopyInResponse:
var copyInResponse = (CopyInResponseMessage)msg;
IsBinary = copyInResponse.IsBinary;
_canWrite = true;
_writeBuf.StartCopyMode();
break;
case BackendMessageCode.CopyOutResponse:
var copyOutResponse = (CopyOutResponseMessage)msg;
IsBinary = copyOutResponse.IsBinary;
_canRead = true;
break;
case BackendMessageCode.CompletedResponse:
throw new InvalidOperationException(
"This API only supports import/export from the client, i.e. COPY commands containing TO/FROM STDIN. " +
"To import/export with files on your PostgreSQL machine, simply execute the command with ExecuteNonQuery. " +
"Note that your data has been successfully imported/exported.");
default:
throw _connector.UnexpectedMessageReceived(msg.Code);
}
}
internal NpgsqlBinaryExporter(NpgsqlConnector connector, string copyToCommand)
{
_connector = connector;
_buf = connector.ReadBuffer;
_typeMapper = connector.TypeMapper;
_columnLen = int.MinValue; // Mark that the (first) column length hasn't been read yet
_column = -1;
try
{
_connector.SendQuery(copyToCommand);
CopyOutResponseMessage copyOutResponse;
var msg = _connector.ReadMessage();
switch (msg.Code)
{
case BackendMessageCode.CopyOutResponse:
copyOutResponse = (CopyOutResponseMessage)msg;
if (!copyOutResponse.IsBinary)
{
throw new ArgumentException("copyToCommand triggered a text transfer, only binary is allowed", nameof(copyToCommand));
}
break;
case BackendMessageCode.CompletedResponse:
throw new InvalidOperationException(
"This API only supports import/export from the client, i.e. COPY commands containing TO/FROM STDIN. " +
"To import/export with files on your PostgreSQL machine, simply execute the command with ExecuteNonQuery. " +
"Note that your data has been successfully imported/exported.");
default:
throw _connector.UnexpectedMessageReceived(msg.Code);
}
NumColumns = copyOutResponse.NumColumns;
_typeHandlerCache = new NpgsqlTypeHandler[NumColumns];
ReadHeader();
}
catch
{
_connector.Break();
throw;
}
}
internal NpgsqlBinaryImporter(NpgsqlConnector connector, string copyFromCommand)
{
_connector = connector;
_buf = connector.WriteBuffer;
_column = -1;
try
{
_connector.SendQuery(copyFromCommand);
CopyInResponseMessage copyInResponse;
var msg = _connector.ReadMessage();
switch (msg.Code)
{
case BackendMessageCode.CopyInResponse:
copyInResponse = (CopyInResponseMessage)msg;
if (!copyInResponse.IsBinary)
{
throw new ArgumentException("copyFromCommand triggered a text transfer, only binary is allowed", nameof(copyFromCommand));
}
break;
case BackendMessageCode.CompletedResponse:
throw new InvalidOperationException(
"This API only supports import/export from the client, i.e. COPY commands containing TO/FROM STDIN. " +
"To import/export with files on your PostgreSQL machine, simply execute the command with ExecuteNonQuery. " +
"Note that your data has been successfully imported/exported.");
default:
throw _connector.UnexpectedMessageReceived(msg.Code);
}
NumColumns = copyInResponse.NumColumns;
_params = new NpgsqlParameter[NumColumns];
_buf.StartCopyMode();
WriteHeader();
}
catch
{
_connector.Break();
throw;
}
}
void Cancel()
{
_state = ImporterState.Cancelled;
_buf.Clear();
_buf.EndCopyMode();
_connector.SendMessage(new CopyFailMessage());
try
{
var msg = _connector.ReadMessage();
// The CopyFail should immediately trigger an exception from the read above.
_connector.Break();
throw new NpgsqlException("Expected ErrorResponse when cancelling COPY but got: " + msg.Code);
}
catch (PostgresException e)
{
if (e.SqlState != "57014")
{
throw;
}
}
}
