/// <summary>
/// This returns a batch of binary data. The data
/// are filled to a supplied buffer. If no buffer is supplied (data_
/// points to NULL) decoder object will provide buffer of its own.
/// </summary>
public void GetData(ref ByteArraySegment data, ref int size)
{
int offset = -1;
this.GetData(ref data, ref size, ref offset);
}
public void GetData(ref ByteArraySegment data, ref int size, ref int offset)
{
ByteArraySegment buffer = data ?? new ByteArraySegment(this.m_buffer);
int bufferSize = data == null ? this.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 (this.m_toWrite == 0)
{
// If we are to encode the beginning of a new message,
// adjust the message offset.
if (this.m_beginning)
{
if (offset == -1)
{
offset = pos;
}
}
if (!this.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 && this.m_toWrite >= bufferSize)
{
data = this.m_writePos;
size = this.m_toWrite;
this.m_writePos = null;
this.m_toWrite = 0;
return;
}
// Copy data to the buffer. If the buffer is full, return.
int toCopy = Math.Min(this.m_toWrite, bufferSize - pos);
if (toCopy != 0)
{
this.m_writePos.CopyTo(0, buffer, pos, toCopy);
pos += toCopy;
this.m_writePos.AdvanceOffset(toCopy);
this.m_toWrite -= toCopy;
}
}
data = buffer;
size = pos;
}
/// <summary>
/// Write the bytes of this ByteArraySegment to the specified destination-ByteArraySegment.
/// </summary>
/// <param name="fromOffset">an offset within this source buffer to start copying from</param>
/// <param name="dest">the destination-ByteArraySegment</param>
/// <param name="destOffset">an offset within the destination buffer to start copying to</param>
/// <param name="toCopy">the number of bytes to copy</param>
public void CopyTo(int fromOffset, [NotNull] ByteArraySegment dest, int destOffset, int toCopy)
{
Buffer.BlockCopy(this.m_innerBuffer, this.Offset + fromOffset, dest.m_innerBuffer, dest.Offset + destOffset, toCopy);
}
/// <summary>
/// Create a new ByteArraySegment that is a shallow-copy of the given ByteArraySegment (with a reference to the same
/// buffer)
/// but with a different offset.
/// </summary>
/// <param name="otherSegment">the source-ByteArraySegment to make a copy of</param>
/// <param name="offset">a value for the Offset property that is distinct from that of the source ByteArraySegment</param>
public ByteArraySegment([NotNull] ByteArraySegment otherSegment, int offset)
{
this.m_innerBuffer = otherSegment.m_innerBuffer;
this.Offset = otherSegment.Offset + offset;
}
/// <summary>
/// Write the bytes of this ByteArraySegment to the specified destination-ByteArraySegment.
/// </summary>
/// <param name="otherSegment">the destination-ByteArraySegment</param>
/// <param name="toCopy">the number of bytes to copy</param>
public void CopyTo([NotNull] ByteArraySegment otherSegment, int toCopy)
{
this.CopyTo(0, otherSegment, 0, toCopy);
}
private void ProcessInput()
{
bool disconnection = false;
int processed;
if (this.m_insize == -1)
{
this.m_insize = 0;
disconnection = true;
}
if (this.m_options.RawSocket)
{
if (this.m_insize == 0 || !this.m_decoder.MessageReadySize(this.m_insize))
{
processed = 0;
}
else
{
processed = this.m_decoder.ProcessBuffer(this.m_inpos, this.m_insize);
}
}
else
{
// Push the data to the decoder.
processed = this.m_decoder.ProcessBuffer(this.m_inpos, this.m_insize);
}
if (processed == -1)
{
disconnection = true;
}
else
{
// Stop polling for input if we got stuck.
if (processed < this.m_insize)
{
this.m_receivingState = ReceiveState.Stuck;
this.m_inpos.AdvanceOffset(processed);
this.m_insize -= processed;
}
else
{
this.m_inpos = null;
this.m_insize = 0;
}
}
// Flush all messages the decoder may have produced.
this.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 (this.m_decoder.Stalled())
{
this.m_ioObject.RemoveSocket(this.m_handle);
this.m_ioEnabled = false;
this.m_state = State.Stalled;
}
else
{
this.Error();
}
}
else if (this.m_receivingState != ReceiveState.Stuck)
{
this.m_decoder.GetBuffer(out this.m_inpos, out this.m_insize);
this.BeginRead(this.m_inpos, this.m_insize);
}
}
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;
}
}
protected void NextStep(ByteArraySegment readPos, int toRead, int state)
{
this.m_readPos = readPos;
this.m_toRead = toRead;
this.State = state;
}
/// <summary>
/// Processes the data in the buffer previously allocated using
/// get_buffer function. size argument specifies the number of bytes
/// actually filled into the buffer. Function returns number of
/// bytes actually processed.
/// </summary>
public int ProcessBuffer(ByteArraySegment data, int size)
{
// Check if we had an error in previous attempt.
if (this.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(this.m_readPos))
{
this.m_readPos.AdvanceOffset(size);
this.m_toRead -= size;
while (this.m_toRead == 0)
{
if (!this.Next())
{
if (this.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 (this.m_toRead == 0)
{
if (!this.Next())
{
if (this.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(this.m_toRead, size - pos);
data.CopyTo(pos, this.m_readPos, 0, toCopy);
this.m_readPos.AdvanceOffset(toCopy);
pos += toCopy;
this.m_toRead -= toCopy;
}
}
