public StreamEngine(AsyncSocket handle, Options options, string endpoint)
{
this.m_handle = handle;
this.m_insize = 0;
this.m_ioEnabled = false;
this.m_sendingState = SendState.Idle;
this.m_receivingState = ReceiveState.Idle;
this.m_outsize = 0;
this.m_session = null;
this.m_options = options;
this.m_plugged = false;
this.m_endpoint = endpoint;
this.m_socket = null;
this.m_encoder = null;
this.m_decoder = null;
this.m_actionsQueue = new Queue <StateMachineAction>();
// Set the socket buffer limits for the underlying socket.
if (this.m_options.SendBuffer != 0)
{
this.m_handle.SendBufferSize = this.m_options.SendBuffer;
}
if (this.m_options.ReceiveBuffer != 0)
{
this.m_handle.ReceiveBufferSize = this.m_options.ReceiveBuffer;
}
}
private void HandleHandshake(Action action, SocketError socketError, int bytesTransferred)
{
int bytesSent;
int bytesReceived;
switch (this.m_handshakeState)
{
case HandshakeState.Closed:
switch (action)
{
case Action.Start:
// Send the 'length' and 'flags' fields of the identity message.
// The 'length' field is encoded in the long format.
this.m_greetingOutputBuffer[this.m_outsize++] = 0xff;
this.m_greetingOutputBuffer.PutLong(this.m_options.Endian, (long)this.m_options.IdentitySize + 1, 1);
this.m_outsize += 8;
this.m_greetingOutputBuffer[this.m_outsize++] = 0x7f;
this.m_outpos = new ByteArraySegment(this.m_greetingOutputBuffer);
this.m_handshakeState = HandshakeState.SendingGreeting;
this.BeginWrite(this.m_outpos, this.m_outsize);
break;
default:
Debug.Assert(false);
break;
}
break;
case HandshakeState.SendingGreeting:
switch (action)
{
case Action.OutCompleted:
bytesSent = StreamEngine.EndWrite(socketError, bytesTransferred);
if (bytesSent == -1)
{
this.Error();
}
else
{
this.m_outpos.AdvanceOffset(bytesSent);
this.m_outsize -= bytesSent;
if (this.m_outsize > 0)
{
this.BeginWrite(this.m_outpos, this.m_outsize);
}
else
{
this.m_greetingBytesRead = 0;
ByteArraySegment greetingSegment = new ByteArraySegment(this.m_greeting, this.m_greetingBytesRead);
this.m_handshakeState = HandshakeState.ReceivingGreeting;
this.BeginRead(greetingSegment, StreamEngine.PreambleSize);
}
}
break;
case Action.ActivateIn:
case Action.ActivateOut:
// nothing to do
break;
default:
Debug.Assert(false);
break;
}
break;
case HandshakeState.ReceivingGreeting:
switch (action)
{
case Action.InCompleted:
bytesReceived = StreamEngine.EndRead(socketError, bytesTransferred);
if (bytesReceived == -1)
{
this.Error();
}
else
{
this.m_greetingBytesRead += bytesReceived;
// check if it is an unversioned protocol
if (this.m_greeting[0] != 0xff || this.m_greetingBytesRead == 10 && (this.m_greeting[9] & 0x01) == 0)
{
this.m_encoder = new V1Encoder(Config.OutBatchSize, this.m_options.Endian);
this.m_encoder.SetMsgSource(this.m_session);
this.m_decoder = new V1Decoder(Config.InBatchSize, this.m_options.MaxMessageSize, this.m_options.Endian);
this.m_decoder.SetMsgSink(this.m_session);
// We have already sent the message header.
// Since there is no way to tell the encoder to
// skip the message header, we simply throw that
// header data away.
int headerSize = this.m_options.IdentitySize + 1 >= 255 ? 10 : 2;
byte[] tmp = new byte[10];
ByteArraySegment bufferp = new ByteArraySegment(tmp);
int bufferSize = headerSize;
this.m_encoder.GetData(ref bufferp, ref bufferSize);
Debug.Assert(bufferSize == headerSize);
// Make sure the decoder sees the data we have already received.
this.m_inpos = new ByteArraySegment(this.m_greeting);
this.m_insize = this.m_greetingBytesRead;
// To allow for interoperability with peers that do not forward
// their subscriptions, we inject a phony subscription
// message into the incoming message stream. To put this
// message right after the identity message, we temporarily
// divert the message stream from session to ourselves.
if (this.m_options.SocketType == ZmqSocketType.Pub || this.m_options.SocketType == ZmqSocketType.Xpub)
{
this.m_decoder.SetMsgSink(this);
}
// handshake is done
this.Activate();
}
else if (this.m_greetingBytesRead < 10)
{
ByteArraySegment greetingSegment = new ByteArraySegment(this.m_greeting, this.m_greetingBytesRead);
this.BeginRead(greetingSegment, StreamEngine.PreambleSize - this.m_greetingBytesRead);
}
else
{
// The peer is using versioned protocol.
// Send the rest of the greeting.
this.m_outpos[this.m_outsize++] = 1; // Protocol version
this.m_outpos[this.m_outsize++] = (byte)this.m_options.SocketType;
this.m_handshakeState = HandshakeState.SendingRestOfGreeting;
this.BeginWrite(this.m_outpos, this.m_outsize);
}
}
break;
case Action.ActivateIn:
case Action.ActivateOut:
// nothing to do
break;
default:
Debug.Assert(false);
break;
}
break;
case HandshakeState.SendingRestOfGreeting:
switch (action)
{
case Action.OutCompleted:
bytesSent = StreamEngine.EndWrite(socketError, bytesTransferred);
if (bytesSent == -1)
{
this.Error();
}
else
{
this.m_outpos.AdvanceOffset(bytesSent);
this.m_outsize -= bytesSent;
if (this.m_outsize > 0)
{
this.BeginWrite(this.m_outpos, this.m_outsize);
}
else
{
ByteArraySegment greetingSegment = new ByteArraySegment(this.m_greeting, this.m_greetingBytesRead);
this.m_handshakeState = HandshakeState.ReceivingRestOfGreeting;
this.BeginRead(greetingSegment, StreamEngine.GreetingSize - this.m_greetingBytesRead);
}
}
break;
case Action.ActivateIn:
case Action.ActivateOut:
// nothing to do
break;
default:
Debug.Assert(false);
break;
}
break;
case HandshakeState.ReceivingRestOfGreeting:
switch (action)
{
case Action.InCompleted:
bytesReceived = StreamEngine.EndRead(socketError, bytesTransferred);
if (bytesReceived == -1)
{
this.Error();
}
else
{
this.m_greetingBytesRead += bytesReceived;
if (this.m_greetingBytesRead < StreamEngine.GreetingSize)
{
ByteArraySegment greetingSegment = new ByteArraySegment(this.m_greeting, this.m_greetingBytesRead);
this.BeginRead(greetingSegment, StreamEngine.GreetingSize - this.m_greetingBytesRead);
}
else
{
if (this.m_greeting[StreamEngine.VersionPos] == 0)
{
// ZMTP/1.0 framing.
this.m_encoder = new V1Encoder(Config.OutBatchSize, this.m_options.Endian);
this.m_encoder.SetMsgSource(this.m_session);
this.m_decoder = new V1Decoder(Config.InBatchSize, this.m_options.MaxMessageSize, this.m_options.Endian);
this.m_decoder.SetMsgSink(this.m_session);
}
else
{
// v1 framing protocol.
this.m_encoder = new V2Encoder(Config.OutBatchSize, this.m_session, this.m_options.Endian);
this.m_decoder = new V2Decoder(Config.InBatchSize, this.m_options.MaxMessageSize, this.m_session, this.m_options.Endian);
}
// handshake is done
this.Activate();
}
}
break;
case Action.ActivateIn:
case Action.ActivateOut:
// nothing to do
break;
default:
Debug.Assert(false);
break;
}
break;
default:
Debug.Assert(false);
break;
}
}
private void Handle(Action action, SocketError socketError, int bytesTransferred)
{
switch (this.m_state)
{
case State.Closed:
switch (action)
{
case Action.Start:
if (this.m_options.RawSocket)
{
this.m_encoder = new RawEncoder(Config.OutBatchSize, this.m_session, this.m_options.Endian);
this.m_decoder = new RawDecoder(Config.InBatchSize, this.m_options.MaxMessageSize, this.m_session, this.m_options.Endian);
this.Activate();
}
else
{
this.m_state = State.Handshaking;
this.m_handshakeState = HandshakeState.Closed;
this.HandleHandshake(action, socketError, bytesTransferred);
}
break;
}
break;
case State.Handshaking:
this.HandleHandshake(action, socketError, bytesTransferred);
break;
case State.Active:
switch (action)
{
case Action.InCompleted:
this.m_insize = StreamEngine.EndRead(socketError, bytesTransferred);
this.ProcessInput();
break;
case Action.ActivateIn:
// if we stuck let's continue, other than that nothing to do
if (this.m_receivingState == ReceiveState.Stuck)
{
this.m_receivingState = ReceiveState.Active;
this.ProcessInput();
}
break;
case Action.OutCompleted:
int bytesSent = StreamEngine.EndWrite(socketError, bytesTransferred);
// IO error has occurred. We stop waiting for output events.
// The engine is not terminated until we detect input error;
// this is necessary to prevent losing incoming messages.
if (bytesSent == -1)
{
this.m_sendingState = SendState.Error;
}
else
{
this.m_outpos.AdvanceOffset(bytesSent);
this.m_outsize -= bytesSent;
this.BeginSending();
}
break;
case Action.ActivateOut:
// if we idle we start sending, other than do nothing
if (this.m_sendingState == SendState.Idle)
{
this.m_sendingState = SendState.Active;
this.BeginSending();
}
break;
default:
Debug.Assert(false);
break;
}
break;
case State.Stalled:
switch (action)
{
case Action.ActivateIn:
// There was an input error but the engine could not
// be terminated (due to the stalled decoder).
// Flush the pending message and terminate the engine now.
this.m_decoder.ProcessBuffer(this.m_inpos, 0);
Debug.Assert(!this.m_decoder.Stalled());
this.m_session.Flush();
this.Error();
break;
case Action.ActivateOut:
break;
}
break;
}
}