npm package discovery and stats viewer.

Discover Tips

  • General search

    [free text search, go nuts!]

  • Package details

    pkg:[package-name]

  • User packages

    @[username]

Sponsor

Optimize Toolset

I’ve always been into building performant and accessible sites, but lately I’ve been taking it extremely seriously. So much so that I’ve been building a tool to help me optimize and monitor the sites that I build to make sure that I’m making an attempt to offer the best experience to those who visit them. If you’re into performant, accessible and SEO friendly sites, you might like it too! You can check it out at Optimize Toolset.

About

Hi, 👋, I’m Ryan Hefner  and I built this site for me, and you! The goal of this site was to provide an easy way for me to check the stats on my npm packages, both for prioritizing issues and updates, and to give me a little kick in the pants to keep up on stuff.

As I was building it, I realized that I was actually using the tool to build the tool, and figured I might as well put this out there and hopefully others will find it to be a fast and useful way to search and browse npm packages as I have.

If you’re interested in other things I’m working on, follow me on Twitter or check out the open source projects I’ve been publishing on GitHub.

I am also working on a Twitter bot for this site to tweet the most popular, newest, random packages from npm. Please follow that account now and it will start sending out packages soon–ish.

Open Software & Tools

This site wouldn’t be possible without the immense generosity and tireless efforts from the people who make contributions to the world and share their work via open source initiatives. Thank you 🙏

© 2024 – Pkg Stats / Ryan Hefner

qpid-proton-messenger

v0.9.0

Published

apache qpid proton messenger AMQP 1.0 library

Downloads

3

Readme

qpid-proton-messenger

Apache qpid proton messenger AMQP 1.0 library http://qpid.apache.org/proton/ https://git-wip-us.apache.org/repos/asf?p=qpid-proton.git

This library provides JavaScript bindings for Apache qpid proton messenger giving AMQP 1.0 support to Node.js and browsers.

Important Note - Modern Browser Needed The JavaScript binding requires ArrayBuffer/TypedArray and WebSocket support. Both of these are available in most "modern" browser versions. The author has only tried running on FireFox and Chrome, though recent Safari, Opera and IE10+ should work too - YMMV. It might be possible to polyfill for older browsers but the author hasn't tried this.

Important Note - WebSocket Transport!!! Before going any further it is really important to realise that the JavaScript bindings to Proton are somewhat different to the bindings for other languages because of the restrictions of the execution environment.

In particular it is very important to note that the JavaScript bindings by default use a WebSocket transport and not a TCP transport, so whilst it's possible to create Server style applications that clients can connect to (e.g. recv.js and send.js) note that: JavaScript clients cannot directly talk to "normal" AMQP applications such as qpidd or (by default) the Java Broker because they use a standard TCP transport.

This is a slightly irksome issue, but there's no getting away from it because it's a security restriction imposed by the browser environment.

Full README https://git-wip-us.apache.org/repos/asf?p=qpid-proton.git;a=blob;f=proton-c/bindings/javascript/README;h=8bfde56632a22bffce4afe791321f4900c5d38d2;hb=HEAD

Examples The examples in the main Proton repository are the best starting point: https://git-wip-us.apache.org/repos/asf?p=qpid-proton.git;a=tree;f=examples/messenger/javascript;h=37964f32a6b3d63e802000b0a2a974ed017e4688;hb=HEAD

In practice the examples follow a fairly similar pattern to the Python bindings the most important thing to bear in mind though is that JavaScript is completely asynchronous/non-blocking, which can catch the unwary.

An application follows the following (rough) steps:

(optional) Set the heap size. It's important to realise that most of the library code is compiled C code and the runtime uses a "virtual heap" to support the underlying malloc/free. This is implemented internally as an ArrayBuffer with a default size of 16777216.

To allocate a larger heap an application must set the PROTON_TOTAL_MEMORY global. In Node.js this would look like (see send.js):

PROTON_TOTAL_MEMORY = 50000000; // Note no var - it needs to be global.

In a browser it would look like (see send.html):

<script type="text/javascript">PROTON_TOTAL_MEMORY = 50000000</script>

Load the library and create a message and messenger. In Node.js this would look like (see send.js):

var proton = require("qpid-proton-messenger");
var message = new proton.Message();
var messenger = new proton.Messenger();

In a browser it would look like (see send.html):

<script type="text/javascript" src="../../../node_modules/qpid-proton-messenger/lib/proton-messenger.js"></script>
<script type="text/javascript" >
var message = new proton.Message();
var messenger = new proton.Messenger();

Set up event handlers as necessary.

messenger.on('error', <error callback>);
messenger.on('work', <work callback>);
messenger.on('subscription', <subscription callback>);

The work callback is triggered on WebSocket events, so in general you would use this to send and receive messages, for example in recv.js we have:

var pumpData = function() {
    while (messenger.incoming()) {
        var t = messenger.get(message);

    console.log("Address: " + message.getAddress());
    console.log("Subject: " + message.getSubject());

    // body is the body as a native JavaScript Object, useful for most real cases.
    //console.log("Content: " + message.body);

    // data is the body as a proton.Data Object, used in this case because
    // format() returns exactly the same representation as recv.c
    console.log("Content: " + message.data.format());

    messenger.accept(t);
   }
};
messenger.on('work', pumpData);

The subscription callback is triggered when the address provided in a call to

messenger.subscribe(<address>);

Gets resolved. An example of its usage can be found in qpid-config.js which is a fully functioning and complete port of the python qpid-config tool. It also illustrates how to do asynchronous request/response based applications.

Aside from the asynchronous aspects the rest of the API is essentially the same as the Python binding aside from minor things such as camel casing method names etc.