Qore zmq Module  1.0.0
Qore::ZMQ::ZSocketStream Class Reference

The ZSocketStream class implements a ZeroMQ STREAM socket. More...

Inheritance diagram for Qore::ZMQ::ZSocketStream:
Qore::Qore::ZMQ::ZSocket

Public Member Methods

 constructor (Qore::ZMQ::ZContext ctx, string endpoint)
 constructs a STREAM zsocket More...
 
 constructor (Qore::ZMQ::ZContext ctx)
 constructs an unconnected STREAM zsocket More...
 
- Public Member Methods inherited from Qore::Qore::ZMQ::ZSocket
nothing attach (*string endpoints, bool do_bind=False)
 Attaches the socket to zero or more endpoints. More...
 
int bind (string format,...)
 Bind the ZSocket to a formatted endpoint. More...
 
nothing connect (string format,...)
 Connects the socket to a formatted endpoint. More...
 
 copy ()
 Throws an exception; copying ZSocket objects is not currently supported. More...
 
nothing disconnect (string format,...)
 Disconnects the socket from a formatted endpoint. More...
 
*string endpoint ()
 Returns the last bound endpoint, if any or nothing if not. More...
 
*string getIdentity ()
 retrieves the socket identity string More...
 
auto getOption (int opt, int bufsize=100)
 Retrieves the value of the given socket option. More...
 
nothing monitor (int events, string format,...)
 Creates a bound PAIR socket on the given endpoint which will send the specified events to a single client. More...
 
ZFrame recvFrame ()
 Receives a frame from the socket. More...
 
ZMsg recvMsg ()
 Receives a message from the socket. More...
 
nothing send (Qore::ZMQ::ZMsg msg)
 Sends the given message over the socket; the message is consumed by this call. More...
 
nothing send (Qore::ZMQ::ZFrame frame, int flags=0)
 Sends the given frame over the socket; the frame is consumed by this call unless Qore::ZMQ::ZFRAME_REUSE is used in the flags argument. More...
 
nothing send (data val,...)
 Sends one or more strings or binary data objects over the socket. More...
 
nothing send ()
 Sends a zero-length message over the socket. More...
 
nothing setIdentity (string id)
 Sets the socket identity string. More...
 
 setOption (int opt, int value)
 Sets the given socket option to the given value. More...
 
 setOption (int opt, bool value)
 Sets the given socket option to the given value. More...
 
 setOption (int opt, data value)
 Sets the given socket option to the given value. More...
 
nothing setRecvHighWaterMark (int value)
 Sets the receive high water mark. More...
 
nothing setRecvTimeout (timeout timeout_ms)
 Sets the receive timeout in milliseconds. More...
 
nothing setSendTimeout (timeout timeout_ms)
 Sets the send timeout in milliseconds. More...
 
nothing setTimeout (timeout timeout_ms)
 Sets the send and receive timeout in milliseconds. More...
 
string type ()
 Returns the socket type as a string. More...
 
nothing unbind (string format,...)
 Unbinds the socket from a formatted endpoint. More...
 
nothing waitRead (timeout timeout_ms)
 Waits for data to read on the socket; if data does not arrive before the timeout expires, a ZSOCKET-TIMEOUT-ERROR exception is thrown. More...
 
nothing waitWrite (timeout timeout_ms)
 Waits for data to be written on the socket; if data is not sent before the timeout expires, a ZSOCKET-TIMEOUT-ERROR exception is thrown. More...
 

Additional Inherited Members

- Static Public Member Methods inherited from Qore::Qore::ZMQ::ZSocket
static list< hash< ZmqPollInfo > > poll (list< hash< ZmqPollInfo >> items, timeout timeout_ms)
 polls multiple sockets and returns all sockets with events More...
 
static nothing proxy (ZSocket frontend, ZSocket backend, *ZSocket capture)
 starts the built-in ZeroMQ proxy to connect messages between two sockets More...
 

Detailed Description

The ZSocketStream class implements a ZeroMQ STREAM socket.

Restrictions:
Qore::PO_NO_NETWORK
Overview
A socket of type STREAM is used to send and receive TCP data from a non-ØMQ peer, when using the tcp:// transport. A STREAM socket can act as client and/or server, sending and/or receiving TCP data asynchronously.

When receiving TCP data, a STREAM socket shall prepend a message part containing the identity of the originating peer to the message before passing it to the application. Messages received are fair-queued from among all connected peers.

When sending TCP data, a STREAM socket shall remove the first part of the message and use it to determine the identity of the peer the message shall be routed to, and unroutable messages shall cause an EHOSTUNREACH or EAGAIN error.

To open a connection to a server, use the ZSocket::connect() call, and then fetch the socket identity using the ZSocket::getIdentity().

To close a specific connection, send the identity frame followed by a zero-length message; see the example below.

When a connection is made, a zero-length message will be received by the application. Similarly, when the peer disconnects (or the connection is lost), a zero-length message will be received by the application.

You must send one identity frame followed by one data frame; the ZMQ_SNDMORE flag is required for identity frames but is ignored for data frames.

Summary of STREAM characteristics
Property Value
Compatible peer sockets none
Direction Bidirectional
Send/receive pattern Unrestricted
Outgoing routing strategy See text
Incoming routing strategy Fair-queued
Action in mute state EAGAIN
Example
ZContext zctx();
ZSocketStream sock(zctx);
sock.bind("tcp://*:8080");
while (True) {
# Get HTTP request; ID frame and then request
ZFrame id = sock.recvFrame();
ZMsg msg = sock.recvMsg();
if (!msg.contentSize())
continue;
# prepare the response
string http_msg = "Hello, World!";
string http_response = sprintf("HTTP/1.0 200 OK\r
Content-Type: text/plain\r
Content-Length: %d\r
\r
%s", http_msg.size(), http_msg);
# Send the ID frame followed by the response
sock.send(id, Qore::ZMQ::ZFRAME_MORE);
sock.send(http_response);
# Closes the connection by sending the ID frame followed by a zero response
sock.send(id, Qore::ZMQ::ZFRAME_MORE);
sock.send();
}
Note
  • This class is not designed to be accessed from multiple threads; it was created without locking for fast and efficient use when used from a single thread. For methods that would be unsafe to use in another thread, any use of such methods in threads other than the thread where the constructor was called will cause a ZSOCKET-THREAD-ERROR to be thrown.

Member Function Documentation

◆ constructor() [1/2]

Qore::ZMQ::ZSocketStream::constructor ( Qore::ZMQ::ZContext  ctx,
string  endpoint 
)

constructs a STREAM zsocket

Example
ZSocketStream sock(ctx, "tcp://127.0.0.1:8001");
Parameters
ctxthe context for the socket
endpointthe endpoint for the socket; the default action is connect
Exceptions
ZSOCKET-CONSTRUCTOR-ERRORthis exception is thrown if there is any error creating the socket
ZSOCKET-CONNECT-ERRORthis exception is thrown if there is any error connecting the socket

◆ constructor() [2/2]

Qore::ZMQ::ZSocketStream::constructor ( Qore::ZMQ::ZContext  ctx)

constructs an unconnected STREAM zsocket

Example
ZSocketStream sock(ctx);
Parameters
ctxthe context for the socket
Exceptions
ZSOCKET-CONSTRUCTOR-ERRORthis exception is thrown if there is any error creating the socket

The documentation for this class was generated from the following file: