private async Task WriteExecFinishAndProcess <TState, TResult>(
TState initialState,
Func <TState, TResult> resultFactory,
Action <TResult, ReadBuffer, int, int> columnBinder)
{
await WriteExecFinish();
await _readBuffer.ReceiveAsync();
read:
var message = _readBuffer.ReadMessage();
switch (message.Type)
{
case MessageType.BindComplete:
goto read;
case MessageType.DataRow:
{
var result
= resultFactory != null
? resultFactory(initialState)
: default;
var columns = _readBuffer.ReadShort();
for (var i = 0; i < columns; i++)
{
var length = _readBuffer.ReadInt();
columnBinder(result, _readBuffer, i, length);
}
goto read;
}
case MessageType.CommandComplete:
return;
case MessageType.ErrorResponse:
throw new InvalidOperationException(_readBuffer.ReadErrorMessage());
default:
throw new NotImplementedException(message.Type.ToString());
}
}
private async Task StartSessionAsync(int millisecondsTimeout)
{
await OpenSocketAsync(millisecondsTimeout);
_writeBuffer = new WriteBuffer(_awaitableSocket);
_readBuffer = new ReadBuffer(_awaitableSocket);
await WriteStartupAsync();
await _readBuffer.ReceiveAsync();
read:
var message = _readBuffer.ReadMessage();
switch (message.Type)
{
case MessageType.AuthenticationRequest:
{
var authenticationRequestType
= (AuthenticationRequestType)_readBuffer.ReadInt();
switch (authenticationRequestType)
{
case AuthenticationRequestType.AuthenticationOk:
{
return;
}
case AuthenticationRequestType.AuthenticationMD5Password:
{
var salt = _readBuffer.ReadBytes(4);
var hash = Hashing.CreateMD5(_password, _user, salt);
await _writeBuffer
.StartMessage('p')
.WriteBytes(hash)
.EndMessage()
.FlushAsync();
await _readBuffer.ReceiveAsync();
goto read;
}
default:
throw new NotImplementedException(authenticationRequestType.ToString());
}
}
case MessageType.ErrorResponse:
throw new InvalidOperationException(_readBuffer.ReadErrorMessage());
case MessageType.BackendKeyData:
case MessageType.EmptyQueryResponse:
case MessageType.ParameterStatus:
case MessageType.ReadyForQuery:
throw new NotImplementedException($"Unhandled MessageType '{message.Type}'");
default:
throw new InvalidOperationException($"Unexpected MessageType '{message.Type}'");
}
}
public async Task ExecuteAsync <TResult>(
string statementName,
Func <TResult> resultFactory,
Action <TResult, ReadBuffer, int, int> columnBinder)
{
ThrowIfDisposed();
ThrowIfNotConnected();
await _writeBuffer
.StartMessage('B')
.WriteNull()
.WriteString(statementName)
.WriteShort(0)
.WriteShort(0)
.WriteShort(1)
.WriteShort(1)
.EndMessage()
.StartMessage('E')
.WriteNull()
.WriteInt(0)
.EndMessage()
.StartMessage('S')
.EndMessage()
.FlushAsync();
await _readBuffer.ReceiveAsync();
read:
var message = ReadMessage();
switch (message.Type)
{
case MessageType.BindComplete:
goto read;
case MessageType.DataRow:
{
var result
= resultFactory != null
? resultFactory()
: default;
var columns = _readBuffer.ReadShort();
for (var i = 0; i < columns; i++)
{
var length = _readBuffer.ReadInt();
columnBinder(result, _readBuffer, i, length);
}
goto read;
}
case MessageType.CommandComplete:
return;
case MessageType.ErrorResponse:
throw new InvalidOperationException(ReadErrorMessage());
default:
throw new NotImplementedException(message.Type.ToString());
}
}