Crate nng

A safe Rust wrapper for NNG

What Is NNG

From the NNG Github Repository:

NNG, like its predecessors nanomsg (and to some extent ZeroMQ), is a lightweight, broker-less library, offering a simple API to solve common recurring messaging problems, such as publish/subscribe, RPC-style request/reply, or service discovery. The API frees the programmer from worrying about details like connection management, retries, and other common considerations, so that they can focus on the application instead of the plumbing.

Nng-rs

This crate provides a safe wrapper around the NNG library, seeking to maintain an API that is similar to the original library. As such, the majority of examples available online should be easy to apply to this crate.

Examples

The following example uses the intra-process transport to set up a request/reply socket pair. The "client" sends a String to the "server" which responds with a nice phrase.

use nng::*;

// Set up the server and listen for connections on the specified address.
let address = "inproc://nng/lib.rs";
let server = Socket::new(Protocol::Rep0).unwrap();
server.listen(address).unwrap();

// Set up the client and connect to the specified address
let mut client = Socket::new(Protocol::Req0).unwrap();
client.dial(address).unwrap();

// Send the request from the client to the server.
let request = b"Ferris"[..].into();
client.send(request).unwrap();

// Receive the message on the server and send back the reply
let request = {
    let req = server.recv().unwrap();
    String::from_utf8(req.to_vec()).unwrap()
    };
assert_eq!(request, "Ferris");
let reply = format!("Hello, {}!", request).as_bytes().into();
server.send(reply).unwrap();

// Get the response on the client side.
let reply = {
    let rep = client.recv().unwrap();
    String::from_utf8(rep.to_vec()).unwrap()
    };
assert_eq!(reply, "Hello, Ferris!");

Additional examples are in the examples directory.

Modules

options

Options available to configure nng constructs.

Structs

Aio	An asynchronous I/O context.
Body	The body of a Message.
Context	A socket context.
Dialer	A constructed and running dialer.
DialerOptions	Configuration utility for nanomsg-next-generation dialers.
Header	The header of a Message.
Listener	A constructed and running listener.
ListenerOptions	Configuration utility for nanomsg-next-generation listeners.
Message	An nng message type.
Pipe	A nanomsg-next-generation pipe.
Socket	A nanomsg-next-generation socket.

Enums

AioResult	The result of an AIO operation.
Error	Errors potentially returned by NNG operations.
PipeEvent	An event that happens on a Pipe instance.
Protocol	Protocols available for use by sockets.
SocketAddr	Represents the addresses used by the underlying transports.

Type Definitions

Result

Specialized Result type for use with nng.