Crate futures_zmq

Futures ZMQ, bringing ZeroMQ any futures runtime.

Futures ZMQ contains wrappers around ZeroMQ Concepts with Futures. It shares an external API with tokio-zmq, but unlike tokio-zmq, futures-zmq is OS and Executor agnostic. This comes at the cost of performance, as futures-zmq relies on spinning up a separate thread for managing the ZeroMQ sockets, while tokio-zmq can avoid this issue by letting mio manage the sockets.

This crate provides Streams, Sinks, and Futures for ZeroMQ Sockets, which deal in structures caled Multiparts. Currently, a Multipart is a simple wrapper around VecDeque<zmq::Message>, but in the future this will be represented as a wrapper around VecDeque<S: zmq::Sendable> with the zmq 0.9 release.

Creating a socket

To get a new socket, you must invoke the Socket builder. The Socket Builder can output a 'raw' Socket, or any specific kind of socket, such as Rep, Req, etc. The result of the builder can be any compatable kind of socket, so specifiying a type is important.

Once you have a socket, if it implements StreamSocket, you can use the socket's .stream() and .recv(), if it implements SinkSocket, you can use the socket's .sink(usize) and .send(Multipart).

Without further ado, creating and using a socket:

extern crate zmq;
extern crate futures;
extern crate tokio;
extern crate futures_zmq;

use std::sync::Arc;

use futures::{Future, Stream};
use futures_zmq::{prelude::*, Socket, Pub, Sub, Error};

fn run() -> Result<(), Error> {
    // Create a new ZeroMQ Context. This context will be used to create all the sockets.
    let context = Arc::new(zmq::Context::new());

    // Create our two sockets using the Socket builder pattern.
    // Note that the variable is named zpub, since pub is a keyword
    let zpub = Pub::builder(Arc::clone(&context))
        .bind("tcp://*:5561")
        .build();

    let sub = Sub::builder(context)
        .bind("tcp://*:5562")
        .filter(b"")
        .build();

    // Create our simple server. This forwards messages from the Subscriber socket to the
    // Publisher socket, and prints them as they go by.
    let runner = zpub
        .join(sub)
        .and_then(|(zpub, sub)| {
            sub.stream()
                .map(|multipart| {
                    for msg in &multipart {
                        if let Some(msg) = msg.as_str() {
                            println!("Forwarding: {}", msg);
                        }
                    }
                    multipart
                })
                .forward(zpub.sink(25))
        });

    // To avoid an infinte doctest, the actual tokio::run is commented out.
    // tokio::run(runner.map(|_| ()).or_else(|e| {
    //     println!("Error: {}", e);
    // })?;
}

Re-exports

pub use self::error::Error;

Modules

async_types
error
prelude	Provide useful types and traits for working with Futures ZMQ.

Structs

Dealer	The DEALER SocketType wrapper type.
Multipart	This type is used for receiving and sending messages in Multipart groups. An application could make using this easier by implementing traits as follows:
Pair	The PAIR SocketType wrapper type.
Pub	The PUB SocketType wrapper type
Pull	The PULL SocketType wrapper type
Push	The PUSH SocketType wrapper type
RecvFuture
Rep	The REP SocketType wrapper type
Req	The REQ SocketType wrapper type
Router	The ROUTER SocketType wrapper type
SESSION
SendFuture
Session
Socket	Defines the raw Socket type. This type should never be interacted with directly, except to create new instances of wrapper types.
Sub	The SUB SocketType wrapper type
Xpub	The XPUB SocketType wrapper type
Xsub	The XSUB SocketType wrapper type