private async Task <object> DecodeAck(IReceiveState state)
{
await state.EnsureEnoughData(16);
var guidBytes = new byte[16];
Buffer.BlockCopy(state.Buffer, state.Offset, guidBytes, 0, guidBytes.Length);
var guid = new Guid(guidBytes);
return(new Ack(guid));
}
public async Task <object> Decode(IReceiveState state)
{
await state.EnsureEnoughData(4);
var type = (TransportMessageType)state.Buffer[state.Offset++];
switch (type)
{
case TransportMessageType.Message:
return(await DecodeMessage(state));
case TransportMessageType.Ack:
return(await DecodeAck(state));
case TransportMessageType.Nak:
return(await DecodeNak(state));
default:
throw new NotSupportedException($"Have not implemented {type} just yet.");
}
}
private async Task <TransportMessage> DecodeMessage(IReceiveState state)
{
var headers = new Dictionary <string, string>();
while (true)
{
if (state.BytesLeftInBuffer < 3)
{
await state.EnsureEnoughData(3);
}
var featureFlag = state.Buffer[state.Offset++];
var stringLength = state.Buffer[state.Offset++];
await state.EnsureEnoughData(stringLength);
var headerName = Encoding.UTF8.GetString(state.Buffer, state.Offset, stringLength);
state.Offset += stringLength;
stringLength = state.Buffer[state.Offset++];
await state.EnsureEnoughData(stringLength);
var headerValue = Encoding.UTF8.GetString(state.Buffer, state.Offset, stringLength);
state.Offset += stringLength;
headers.Add(headerName, headerValue);
if ((featureFlag & (byte)TransportHeaderFeatureFlags.EndOfHeaders) != 0)
{
break;
}
}
if (!headers.TryGetValue(Headers.ContentLength, out var contentLengthValue))
{
throw new InvalidOperationException($"Expected header '{Headers.ContentLength}' to be specified.");
}
Guid messageId;
if (headers.TryGetValue(Headers.MessageId, out var messageIdStr))
{
messageId = Guid.Parse(messageIdStr);
}
else
{
throw new InvalidOperationException("All messages must have an id.");
}
var contentLength = int.Parse(contentLengthValue);
state.EnsureBufferSize(contentLength);
var bytesLeft = contentLength - state.BytesLeftInBuffer;
await state.EnsureEnoughData(bytesLeft);
var body = _transportSerializer.Deserialize(state.Buffer, state.Offset, contentLength, headers);
state.Offset += contentLength;
return(new TransportMessage(body)
{
Id = messageId,
Headers = headers
});
}
public async Task <byte> DecodeHandshake(IReceiveState receiver)
{
await receiver.EnsureEnoughData(1);
return(receiver.Buffer[receiver.Offset++]);
}