a1_socket: Socket Functions

In pbdZMQ: Programming with Big Data -- Interface to 'ZeroMQ'

Socket Functions

Description

Socket functions

Usage

zmq.socket(ctx, type = ZMQ.ST()$REP)

zmq.close(socket)

zmq.bind(socket, endpoint, MC = ZMQ.MC())

zmq.connect(socket, endpoint, MC = ZMQ.MC())

zmq.disconnect(socket, endpoint, MC = ZMQ.MC())

zmq.setsockopt(socket, option.name, option.value, MC = ZMQ.MC())

zmq.getsockopt(socket, option.name, option.value, MC = ZMQ.MC())

Arguments

ctx	a ZMQ context
type	a socket type
socket	a ZMQ socket
endpoint	a ZMQ socket endpoint
MC	a message control, see ZMQ.MC() for details
option.name	an option name to the socket
option.value	an option value to the option name

Details

zmq.socket() initials a ZMQ socket given a ZMQ context ctx and a socket type. See ZMQ.ST() for the possible values of type. ZMQ defines several patterns for the socket type and utilize them to communicate in different ways including request-reply, publish-subscribe, pipeline, exclusive pair, and naive patterns.

zmq.close() destroys the ZMQ socket.

zmq.bind() binds the socket to a local endpoint and then accepts incoming connections on that endpoint. See endpoint next for details.

zmq.connect() connects the socket to a remote endpoint and then accepts outgoing connections on that endpoint. See endpoint next for details.

endpoint is a string consisting of a transport :// followed by an address. The transport specifies the underlying protocol to use. The address specifies the transport-specific address to bind to. pbdZMQ/ZMQ provides the following transports:

Transport	Usage
tcp	unicast transport using TCP
ipc	local inter-process communication transport
inproc	local in-process (inter-thread) communication transport
pgm,epgm	reliable multicast transport using PGM

*** warning: epgm is not turned on by default in the pbdZMQ's internal ZeroMQ library.
*** warning: ipc is not supported in Windows system.

zmq.setsockopt() is to set/change socket options.

zmq.getsockopt() is to get socket options and returns option.value.

Value

zmq.socket() returns an R external pointer (socket) generated by ZMQ C API pointing to a socket if successful, otherwise returns an R NULL and sets errno to the error value, see ZeroMQ manual for details.

zmq.close() destroys the socket reference/pointer (socket) and returns 0 if successful, otherwise returns -1 and sets errno to the error value, see ZeroMQ manual for details.

zmq.bind() binds the socket to specific endpoint and returns 0 if successful, otherwise returns -1 and sets errno to the error value, see ZeroMQ manual for details.

zmq.connect() connects the socket to specific endpoint and returns 0 if successful, otherwise returns -1 and sets errno to the error value, see ZeroMQ manual for details.

zmq.setsockopt() sets/changes the socket option and returns 0 if successful, otherwise returns -1 and sets errno to the error value, see ZeroMQ manual for details.

zmq.getsockopt() returns the value of socket option, see ZeroMQ manual for details.

Author(s)

Wei-Chen Chen [e-mail].

References

ZeroMQ/4.1.0 API Reference: https://libzmq.readthedocs.io/en/zeromq4-1/

Programming with Big Data in R Website: https://pbdr.org/

See Also

zmq.ctx.new(), zmq.ctx.destroy().

Examples

## Not run: 
### Using request-reply pattern.

### At the server, run next in background or the other windows.
library(pbdZMQ, quietly = TRUE)

context <- zmq.ctx.new()
responder <- zmq.socket(context, ZMQ.ST()$REP)
zmq.bind(responder, "tcp://*:5555")
zmq.close(responder)
zmq.ctx.destroy(context)


### At a client, run next in foreground.
library(pbdZMQ, quietly = TRUE)

context <- zmq.ctx.new()
requester <- zmq.socket(context, ZMQ.ST()$REQ)
zmq.connect(requester, "tcp://localhost:5555")
zmq.close(requester)
zmq.ctx.destroy(context)

## End(Not run)

pbdZMQ documentation built on Sept. 11, 2024, 5:36 p.m.