public ByteArraySegment(ByteArraySegment otherSegment, int offset)
{
m_innerBuffer = otherSegment.m_innerBuffer;
Offset = otherSegment.Offset + offset;
}
public void CopyTo(ByteArraySegment otherSegment, int toCopy)
{
CopyTo(0, otherSegment, 0, toCopy);
}
public void CopyTo(int fromOffset, ByteArraySegment dest, int destOffset, int toCopy)
{
Buffer.BlockCopy(m_innerBuffer, Offset + fromOffset, dest.m_innerBuffer, dest.Offset + destOffset, toCopy);
}
private int Write(ByteArraySegment data, int size)
{
int nbytes = 0;
try
{
nbytes = m_handle.Send((byte[]) data, data.Offset, size, SocketFlags.None);
}
catch (SocketException ex)
{
// If not a single byte can be written to the socket in non-blocking mode
// we'll get an error (this may happen during the speculative write).
if (ex.SocketErrorCode == SocketError.WouldBlock)
{
return 0;
}
else if ((
ex.SocketErrorCode == SocketError.NetworkDown ||
ex.SocketErrorCode == SocketError.NetworkReset ||
ex.SocketErrorCode == SocketError.HostUnreachable ||
ex.SocketErrorCode == SocketError.ConnectionAborted ||
ex.SocketErrorCode == SocketError.TimedOut ||
ex.SocketErrorCode == SocketError.ConnectionReset))
{
return -1;
}
else
{
Debug.Assert(false);
}
}
return nbytes;
}
private bool Handshake()
{
Debug.Assert(m_handshaking);
// Receive the greeting.
while (m_greetingBytesRead < GreetingSize)
{
ByteArraySegment greetingSegment = new ByteArraySegment(m_greeting, m_greetingBytesRead);
int n = Read(greetingSegment, GreetingSize - m_greetingBytesRead);
if (n == -1)
{
Error();
return false;
}
if (n == 0)
return false;
m_greetingBytesRead += n;
// We have received at least one byte from the peer.
// If the first byte is not 0xff, we know that the
// peer is using unversioned protocol.
if (m_greeting[0] != 0xff)
break;
if (m_greetingBytesRead < 10)
continue;
// Inspect the right-most bit of the 10th byte (which coincides
// with the 'flags' field if a regular message was sent).
// Zero indicates this is a header of identity message
// (i.e. the peer is using the unversioned protocol).
if ((m_greeting[9] & 0x01) == 0)
break;
// The peer is using versioned protocol.
// Send the rest of the greeting, if necessary.
if (!(((byte[]) m_outpos) == ((byte[]) m_greetingOutputBuffer) &&
m_outpos.Offset + m_outsize == GreetingSize))
{
if (m_outsize == 0)
m_ioObject.SetPollout(m_handle);
m_outpos[m_outsize++] = 1; // Protocol version
m_outpos[m_outsize++] = (byte) m_options.SocketType;
}
}
// Is the peer using the unversioned protocol?
// If so, we send and receive rests of identity
// messages.
if (m_greeting[0] != 0xff || (m_greeting[9] & 0x01) == 0)
{
m_encoder = new Encoder(Config.OutBatchSize);
m_encoder.SetMsgSource(m_session);
m_decoder = new Decoder(Config.InBatchSize, m_options.Maxmsgsize);
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;
byte[] tmp = new byte[10];
ByteArraySegment 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 subsription
// message into the incomming 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);
}
else if (m_greeting[VersionPos] == 0)
{
// ZMTP/1.0 framing.
m_encoder = new Encoder(Config.OutBatchSize);
m_encoder.SetMsgSource(m_session);
m_decoder = new Decoder(Config.InBatchSize, m_options.Maxmsgsize);
m_decoder.SetMsgSink(m_session);
}
else
{
// v1 framing protocol.
m_encoder = new V1Encoder(Config.OutBatchSize, m_session);
m_decoder = new V1Decoder(Config.InBatchSize, m_options.Maxmsgsize, m_session);
}
// Start polling for output if necessary.
if (m_outsize == 0)
m_ioObject.SetPollout(m_handle);
// Handshaking was successful.
// Switch into the normal message flow.
m_handshaking = false;
return true;
}
public void Plug(IOThread ioThread,
SessionBase session)
{
Debug.Assert(!m_plugged);
m_plugged = true;
// Connect to session object.
Debug.Assert(m_session == null);
Debug.Assert(session != null);
m_session = session;
m_socket = m_session.Socket;
m_ioObject = new IOObject(null);
m_ioObject.SetHandler(this);
// Connect to I/O threads poller object.
m_ioObject.Plug(ioThread);
m_ioObject.AddFd(m_handle);
// 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((long) m_options.IdentitySize + 1, 1);
m_outsize += 8;
m_greetingOutputBuffer[m_outsize++] = ((byte) 0x7f);
m_outpos = new ByteArraySegment(m_greetingOutputBuffer);
m_ioObject.SetPollin(m_handle);
m_ioObject.SetPollout(m_handle);
// Flush all the data that may have been already received downstream.
InEvent();
}
public void OutEvent()
{
// If write buffer is empty, try to read new data from the encoder.
if (m_outsize == 0)
{
m_outpos = null;
m_encoder.GetData(ref m_outpos, ref m_outsize);
// If there is no data to send, stop polling for output.
if (m_outsize == 0)
{
m_ioObject.ResetPollout(m_handle);
return;
}
}
// If there are any data to write in write buffer, write as much as
// possible to the socket. Note that amount of data to write can be
// arbitratily large. However, we assume that underlying TCP layer has
// limited transmission buffer and thus the actual number of bytes
// written should be reasonably modest.
int nbytes = Write(m_outpos, m_outsize);
// 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 incomming messages.
if (nbytes == -1)
{
m_ioObject.ResetPollout(m_handle);
return;
}
m_outpos.AdvanceOffset(nbytes);
m_outsize -= nbytes;
// If we are still handshaking and there are no data
// to send, stop polling for output.
if (m_handshaking)
if (m_outsize == 0)
m_ioObject.ResetPollout(m_handle);
}
