private void HandleHandshake(Action action, SocketError socketError, int bytesTransferred)
{
int bytesSent;
int bytesReceived;
switch (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.
m_greetingOutputBuffer[m_outsize++] = ((byte)0xff);
m_greetingOutputBuffer.PutLong(m_options.Endian, (long)m_options.IdentitySize + 1, 1);
m_outsize += 8;
m_greetingOutputBuffer[m_outsize++] = ((byte)0x7f);
m_outpos = new ByteArraySegment(m_greetingOutputBuffer);
m_handshakeState = HandshakeState.SendingGreeting;
BeginWrite(m_outpos, m_outsize);
break;
default:
Debug.Assert(false);
break;
}
break;
case HandshakeState.SendingGreeting:
switch (action)
{
case Action.OutCompleted:
bytesSent = EndWrite(socketError, bytesTransferred);
if (bytesSent == -1)
{
Error();
}
else
{
m_outpos.AdvanceOffset(bytesSent);
m_outsize -= bytesSent;
if (m_outsize > 0)
{
BeginWrite(m_outpos, m_outsize);
}
else
{
m_greetingBytesRead = 0;
var greetingSegment = new ByteArraySegment(m_greeting, m_greetingBytesRead);
m_handshakeState = HandshakeState.ReceivingGreeting;
BeginRead(greetingSegment, 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 = EndRead(socketError, bytesTransferred);
if (bytesReceived == -1)
{
Error();
}
else
{
m_greetingBytesRead += bytesReceived;
// check if it is an unversion protocol
if (m_greeting[0] != 0xff || (m_greetingBytesRead == 10 && (m_greeting[9] & 0x01) == 0))
{
m_encoder = new V1Encoder(Config.OutBatchSize, m_options.Endian);
m_encoder.SetMsgSource(m_session);
m_decoder = new V1Decoder(Config.InBatchSize, m_options.MaxMessageSize, m_options.Endian);
m_decoder.SetMsgSink(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 = m_options.IdentitySize + 1 >= 255 ? 10 : 2;
var tmp = new byte[10];
var bufferp = new ByteArraySegment(tmp);
int bufferSize = headerSize;
m_encoder.GetData(ref bufferp, ref bufferSize);
Debug.Assert(bufferSize == headerSize);
// Make sure the decoder sees the data we have already received.
m_inpos = new ByteArraySegment(m_greeting);
m_insize = 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 (m_options.SocketType == ZmqSocketType.Pub || m_options.SocketType == ZmqSocketType.Xpub)
m_decoder.SetMsgSink(this);
ActivateOut();
}
else if (m_greetingBytesRead < 10)
{
var greetingSegment = new ByteArraySegment(m_greeting, m_greetingBytesRead);
BeginRead(greetingSegment, PreambleSize - m_greetingBytesRead);
}
else
{
// The peer is using versioned protocol.
// Send the rest of the greeting.
m_outpos[m_outsize++] = 1; // Protocol version
m_outpos[m_outsize++] = (byte)m_options.SocketType;
m_handshakeState = HandshakeState.SendingRestOfGreeting;
BeginWrite(m_outpos, 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 = EndWrite(socketError, bytesTransferred);
if (bytesSent == -1)
{
Error();
}
else
{
m_outpos.AdvanceOffset(bytesSent);
m_outsize -= bytesSent;
if (m_outsize > 0)
{
BeginWrite(m_outpos, m_outsize);
}
else
{
var greetingSegment = new ByteArraySegment(m_greeting, m_greetingBytesRead);
m_handshakeState = HandshakeState.ReceivingRestOfGreeting;
BeginRead(greetingSegment, GreetingSize - 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 = EndRead(socketError, bytesTransferred);
if (bytesReceived == -1)
{
Error();
}
else
{
m_greetingBytesRead += bytesReceived;
if (m_greetingBytesRead < GreetingSize)
{
var greetingSegment = new ByteArraySegment(m_greeting, m_greetingBytesRead);
BeginRead(greetingSegment, GreetingSize);
}
else
{
if (m_greeting[VersionPos] == 0)
{
// ZMTP/1.0 framing.
m_encoder = new V1Encoder(Config.OutBatchSize, m_options.Endian);
m_encoder.SetMsgSource(m_session);
m_decoder = new V1Decoder(Config.InBatchSize, m_options.MaxMessageSize, m_options.Endian);
m_decoder.SetMsgSink(m_session);
}
else
{
// v1 framing protocol.
m_encoder = new V2Encoder(Config.OutBatchSize, m_session, m_options.Endian);
m_decoder = new V2Decoder(Config.InBatchSize, m_options.MaxMessageSize, m_session, m_options.Endian);
}
// handshake is done
Activate();
}
}
break;
case Action.ActivateIn:
case Action.ActivateOut:
// nothing to do
break;
default:
Debug.Assert(false);
break;
}
break;
default:
Debug.Assert(false);
break;
}
}
public void GetData(ref ByteArraySegment data, ref int size, ref int offset)
{
ByteArraySegment buffer = data ?? new ByteArraySegment(m_buf);
int bufferSize = data == null ? m_buffersize : size;
int pos = 0;
while (pos < bufferSize)
{
// If there are no more data to return, run the state machine.
// If there are still no data, return what we already have
// in the buffer.
if (m_toWrite == 0)
{
// If we are to encode the beginning of a new message,
// adjust the message offset.
if (m_beginning)
{
if (offset == -1)
{
offset = pos;
}
}
if (!Next())
{
break;
}
}
// If there are no data in the buffer yet and we are able to
// fill whole buffer in a single go, let's use zero-copy.
// There's no disadvantage to it as we cannot stuck multiple
// messages into the buffer anyway. Note that subsequent
// write(s) are non-blocking, thus each single write writes
// at most SO_SNDBUF bytes at once not depending on how large
// is the chunk returned from here.
// As a consequence, large messages being sent won't block
// other engines running in the same I/O thread for excessive
// amounts of time.
if (pos == 0 && data == null && m_toWrite >= bufferSize)
{
data = m_writePos;
size = m_toWrite;
m_writePos = null;
m_toWrite = 0;
return;
}
// Copy data to the buffer. If the buffer is full, return.
int toCopy = Math.Min(m_toWrite, bufferSize - pos);
if (toCopy != 0)
{
m_writePos.CopyTo(0, buffer, pos, toCopy);
pos += toCopy;
m_writePos.AdvanceOffset(toCopy);
m_toWrite -= toCopy;
}
}
data = buffer;
size = pos;
}
// Processes the data in the buffer previously allocated using
// get_buffer function. size_ argument specifies nemuber of bytes
// actually filled into the buffer. Function returns number of
// bytes actually processed.
public int ProcessBuffer(ByteArraySegment data, int size)
{
// Check if we had an error in previous attempt.
if (State < 0)
{
return(-1);
}
// In case of zero-copy simply adjust the pointers, no copying
// is required. Also, run the state machine in case all the data
// were processed.
if (data != null && data.Equals(m_readPos))
{
m_readPos.AdvanceOffset(size);
m_toRead -= size;
while (m_toRead == 0)
{
if (!Next())
{
if (State < 0)
{
return(-1);
}
return(size);
}
}
return(size);
}
int pos = 0;
while (true)
{
// Try to get more space in the message to fill in.
// If none is available, return.
while (m_toRead == 0)
{
if (!Next())
{
if (State < 0)
{
return(-1);
}
return(pos);
}
}
// If there are no more data in the buffer, return.
if (pos == size)
{
return(pos);
}
// Copy the data from buffer to the message.
int toCopy = Math.Min(m_toRead, size - pos);
data.CopyTo(pos, m_readPos, 0, toCopy);
m_readPos.AdvanceOffset(toCopy);
pos += toCopy;
m_toRead -= toCopy;
}
}
private void ProcessInput()
{
bool disconnection = false;
int processed;
if (m_insize == -1)
{
m_insize = 0;
disconnection = true;
}
if (m_options.RawSocket)
{
if (m_insize == 0 || !m_decoder.MessageReadySize(m_insize))
{
processed = 0;
}
else
{
processed = m_decoder.ProcessBuffer(m_inpos, m_insize);
}
}
else
{
// Push the data to the decoder.
processed = m_decoder.ProcessBuffer(m_inpos, m_insize);
}
if (processed == -1)
{
disconnection = true;
}
else
{
// Stop polling for input if we got stuck.
if (processed < m_insize)
{
m_receivingState = ReceiveState.Stuck;
m_inpos.AdvanceOffset(processed);
m_insize -= processed;
}
else
{
m_inpos = null;
m_insize = 0;
}
}
// Flush all messages the decoder may have produced.
m_session.Flush();
// An input error has occurred. If the last decoded message
// has already been accepted, we terminate the engine immediately.
// Otherwise, we stop waiting for socket events and postpone
// the termination until after the message is accepted.
if (disconnection)
{
if (m_decoder.Stalled())
{
m_ioObject.RemoveSocket(m_handle);
m_ioEnabled = false;
m_state = State.Stalled;
}
else
{
Error();
}
}
else if (m_receivingState != ReceiveState.Stuck)
{
m_decoder.GetBuffer(out m_inpos, out m_insize);
BeginRead(m_inpos, m_insize);
}
}
private void HandleHandshake(Action action, SocketError socketError, int bytesTransferred)
{
int bytesSent;
int bytesReceived;
switch (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.
m_greetingOutputBuffer[m_outsize++] = ((byte)0xff);
m_greetingOutputBuffer.PutLong(m_options.Endian, (long)m_options.IdentitySize + 1, 1);
m_outsize += 8;
m_greetingOutputBuffer[m_outsize++] = ((byte)0x7f);
m_outpos = new ByteArraySegment(m_greetingOutputBuffer);
m_handshakeState = HandshakeState.SendingGreeting;
BeginWrite(m_outpos, m_outsize);
break;
default:
Debug.Assert(false);
break;
}
break;
case HandshakeState.SendingGreeting:
switch (action)
{
case Action.OutCompleted:
bytesSent = EndWrite(socketError, bytesTransferred);
if (bytesSent == -1)
{
Error();
}
else
{
m_outpos.AdvanceOffset(bytesSent);
m_outsize -= bytesSent;
if (m_outsize > 0)
{
BeginWrite(m_outpos, m_outsize);
}
else
{
m_greetingBytesRead = 0;
var greetingSegment = new ByteArraySegment(m_greeting, m_greetingBytesRead);
m_handshakeState = HandshakeState.ReceivingGreeting;
BeginRead(greetingSegment, 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 = EndRead(socketError, bytesTransferred);
if (bytesReceived == -1)
{
Error();
}
else
{
m_greetingBytesRead += bytesReceived;
// check if it is an unversion protocol
if (m_greeting[0] != 0xff || (m_greetingBytesRead == 10 && (m_greeting[9] & 0x01) == 0))
{
m_encoder = new V1Encoder(Config.OutBatchSize, m_options.Endian);
m_encoder.SetMsgSource(m_session);
m_decoder = new V1Decoder(Config.InBatchSize, m_options.MaxMessageSize, m_options.Endian);
m_decoder.SetMsgSink(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 = m_options.IdentitySize + 1 >= 255 ? 10 : 2;
var tmp = new byte[10];
var bufferp = new ByteArraySegment(tmp);
int bufferSize = headerSize;
m_encoder.GetData(ref bufferp, ref bufferSize);
Debug.Assert(bufferSize == headerSize);
// Make sure the decoder sees the data we have already received.
m_inpos = new ByteArraySegment(m_greeting);
m_insize = 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 (m_options.SocketType == ZmqSocketType.Pub || m_options.SocketType == ZmqSocketType.Xpub)
{
m_decoder.SetMsgSink(this);
}
ActivateOut();
}
else if (m_greetingBytesRead < 10)
{
var greetingSegment = new ByteArraySegment(m_greeting, m_greetingBytesRead);
BeginRead(greetingSegment, PreambleSize - m_greetingBytesRead);
}
else
{
// The peer is using versioned protocol.
// Send the rest of the greeting.
m_outpos[m_outsize++] = 1; // Protocol version
m_outpos[m_outsize++] = (byte)m_options.SocketType;
m_handshakeState = HandshakeState.SendingRestOfGreeting;
BeginWrite(m_outpos, 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 = EndWrite(socketError, bytesTransferred);
if (bytesSent == -1)
{
Error();
}
else
{
m_outpos.AdvanceOffset(bytesSent);
m_outsize -= bytesSent;
if (m_outsize > 0)
{
BeginWrite(m_outpos, m_outsize);
}
else
{
var greetingSegment = new ByteArraySegment(m_greeting, m_greetingBytesRead);
m_handshakeState = HandshakeState.ReceivingRestOfGreeting;
BeginRead(greetingSegment, GreetingSize - 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 = EndRead(socketError, bytesTransferred);
if (bytesReceived == -1)
{
Error();
}
else
{
m_greetingBytesRead += bytesReceived;
if (m_greetingBytesRead < GreetingSize)
{
var greetingSegment = new ByteArraySegment(m_greeting, m_greetingBytesRead);
BeginRead(greetingSegment, GreetingSize);
}
else
{
if (m_greeting[VersionPos] == 0)
{
// ZMTP/1.0 framing.
m_encoder = new V1Encoder(Config.OutBatchSize, m_options.Endian);
m_encoder.SetMsgSource(m_session);
m_decoder = new V1Decoder(Config.InBatchSize, m_options.MaxMessageSize, m_options.Endian);
m_decoder.SetMsgSink(m_session);
}
else
{
// v1 framing protocol.
m_encoder = new V2Encoder(Config.OutBatchSize, m_session, m_options.Endian);
m_decoder = new V2Decoder(Config.InBatchSize, m_options.MaxMessageSize, m_session, m_options.Endian);
}
// handshake is done
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 (m_state)
{
case State.Closed:
switch (action)
{
case Action.Start:
if (m_options.RawSocket)
{
m_encoder = new RawEncoder(Config.OutBatchSize, m_session, m_options.Endian);
m_decoder = new RawDecoder(Config.InBatchSize, m_options.MaxMessageSize, m_session, m_options.Endian);
Activate();
}
else
{
m_state = State.Handshaking;
m_handshakeState = HandshakeState.Closed;
HandleHandshake(action, socketError, bytesTransferred);
}
break;
}
break;
case State.Handshaking:
HandleHandshake(action, socketError, bytesTransferred);
break;
case State.Active:
switch (action)
{
case Action.InCompleted:
m_insize = EndRead(socketError, bytesTransferred);
ProcessInput();
break;
case Action.ActivateIn:
// if we stuck let's continue, other than that nothing to do
if (m_receivingState == ReceiveState.Stuck)
{
m_receivingState = ReceiveState.Active;
ProcessInput();
}
break;
case Action.OutCompleted:
int bytesSent = 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)
{
m_sendingState = SendState.Error;
}
else
{
m_outpos.AdvanceOffset(bytesSent);
m_outsize -= bytesSent;
BeginSending();
}
break;
case Action.ActivateOut:
// if we idle we start sending, other than do nothing
if (m_sendingState == SendState.Idle)
{
m_sendingState = SendState.Active;
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.
m_decoder.ProcessBuffer(m_inpos, 0);
Debug.Assert(!m_decoder.Stalled());
m_session.Flush();
Error();
break;
case Action.ActivateOut:
break;
}
break;
}
}