Next-generation ZeroMQ bindings for Node.js
npm install runsa-zeromq  
ØMQ bindings for Node.js. The goals of this library are:
* Semantically similar to the native ØMQ library, while sticking to JavaScript idioms.
* Use modern JavaScript and Node.js features such as async/await and async iterators.
* High performance.
* Fully usable with TypeScript (3.6+).
* ZeroMQ.js API reference.
* ZeroMQ project documentation.
* Note: The Node.js examples on zeromq.org do not yet reflect the new API, but the Guide in particular is still a good introduction to ZeroMQ for new users.
* Installation
* Prebuilt binaries
* Building from source
* Examples
* Push/Pull
* Pub/Sub
* More examples
* Compatibility layer for version 4/5
* Contribution
* History
Install ZeroMQ.js with prebuilt binaries:
``sh`
npm install zeromq@6.0.0-beta.6
Requirements for prebuilt binaries:
* Node.js 10.2+ or Electron 3+ (requires a N-API version 3+)
The following platforms have a prebuilt binary available:
* Linux on x86-64/armv7/armv8 with libstdc++.so.6.0.21+ (glibc++ 3.4.21+), for example:
* Debian 9+ (Stretch or later)
* Ubuntu 16.04+ (Xenial or later)
* CentOS 8+
* Linux on x86-64 with musl, for example:
* Alpine 3.3+
* MacOS 10.9+ on x86-64
* Windows on x86/x86-64
If a prebuilt binary is not available for your platform, installing will attempt to start a build from source.
If a prebuilt binary is unavailable or if you want to pass certain options during build, you can build this package from source.
Make sure you have the following installed before attempting to build from source:
* Node.js 10+ or Electron 3+
* A working C++17 compiler toolchain with make
* Python 2.7 (or Python 3 with Node 12.13+)
* CMake 2.8+
* curl
To install from source
`sh`
npm install zeromq@6.0.0-beta.6 --build-from-source
If you want to link against a shared ZeroMQ library, you can build skip downloading libzmq and link with the installed library instead as follows:
`sh`
npm install zeromq@6.0.0-beta.6 --zmq-shared
If you wish to use any DRAFT sockets then it is also necessary to compile the library from source:
`sh`
npm install zeromq@6.0.0-beta.6 --zmq-draft
Note: The examples assume the reader is familiar with ZeroMQ. If you are new to ZeroMQ, please start with the ZeroMQ documentation.
More examples can be found in the examples directory.
This example demonstrates how a producer pushes information onto a
socket and how a worker pulls information from the socket.
`js
const zmq = require("zeromq")
async function run() {
const sock = new zmq.Push
await sock.bind("tcp://127.0.0.1:3000")
console.log("Producer bound to port 3000")
while (true) {
await sock.send("some work")
await new Promise(resolve => setTimeout(resolve, 500))
}
}
run()
`
`js
const zmq = require("zeromq")
async function run() {
const sock = new zmq.Pull
sock.connect("tcp://127.0.0.1:3000")
console.log("Worker connected to port 3000")
for await (const [msg] of sock) {
console.log("work: %s", msg.toString())
}
}
run()
`
This example demonstrates using zeromq in a classic Pub/Sub,
Publisher/Subscriber, application.
`js
const zmq = require("zeromq")
async function run() {
const sock = new zmq.Publisher
await sock.bind("tcp://127.0.0.1:3000")
console.log("Publisher bound to port 3000")
while (true) {
console.log("sending a multipart message envelope")
await sock.send(["kitty cats", "meow!"])
await new Promise(resolve => setTimeout(resolve, 500))
}
}
run()
`
`js
const zmq = require("zeromq")
async function run() {
const sock = new zmq.Subscriber
sock.connect("tcp://127.0.0.1:3000")
sock.subscribe("kitty cats")
console.log("Subscriber connected to port 3000")
for await (const [topic, msg] of sock) {
console.log("received a message related to:", topic, "containing message:", msg)
}
}
run()
`
More advanced examples can be found in the examples directory of this repository.
Or you can browse the API reference documentation to see all socket types, methods & options as well as more detailed information about how to apply them.
The next generation version of the library features a compatibility layer for ZeroMQ.js versions 4 and 5. This is recommended for users upgrading from previous versions.
Example:
`js
const zmq = require("zeromq/v5-compat")
const pub = zmq.socket("pub")
const sub = zmq.socket("sub")
pub.bind("tcp://*:3456", err => {
if (err) throw err
sub.connect("tcp://127.0.0.1:3456")
pub.send("message")
sub.on("message", msg => {
// Handle received message...
})
})
`
In order to develop and test the library, you'll need the tools required to build from source (see above).
Additionally, having clang-format is strongly recommended.
Socket and context options can be set at runtime, even if they are not implemented by this library. By design, this requires no recompilation if the built version of ZeroMQ has support for them. This allows library users to test and use options that have been introduced in recent versions of ZeroMQ without having to modify this library. Of course we'd love to include support for new options in an idiomatic way.
Options can be set as follows:
`js
const {Dealer} = require("zeromq")
/* This defines an accessor named 'sendHighWaterMark', which corresponds to
the constant ZMQ_SNDHWM, which is defined as '23' in zmq.h. The option takes
integers. The accessor name has been converted to idiomatic JavaScript.
Of course, this particular option already exists in this library. */
class MyDealer extends Dealer {
get sendHighWaterMark(): number {
return this.getInt32Option(23)
}
set sendHighWaterMark(value: number) {
this.setInt32Option(23, value)
}
}
const sock = new MyDealer({sendHighWaterMark: 456})
`
When submitting pull requests for new socket/context options, please consider the following:
* The option is documented in the TypeScript interface.
* The option is only added to relevant socket types, and if the ZMQ_ constant has a prefix indicating which type it applies to, it is stripped from the name as it is exposed in JavaScript.
* The name as exposed in this library is idiomatic for JavaScript, spelling out any abbreviations and using proper camelCase naming conventions.
* The option is a value that can be set on a socket, and you don't think it should actually be a method.
The test suite can be run with:
`sh`
npm install
npm run dev:build
npm run dev:test
Or, if you prefer:
`sh`
yarn
yarn run dev:build
yarn run dev:test
The test suite will validate and fix the coding style, run all unit tests and verify the validity of the included TypeScript type definitions.
Some tests are not enabled by default:
* API Compatibility tests from ZeroMQ 5.x have been disabled by default. You can include the tests with INCLUDE_COMPAT_TESTS=1 npm run dev:test
* Some transports are not reliable on some older versions of ZeroMQ, the relevant tests will be skipped for those versions automatically.
To publish a new version, run:
`sh`
npm version
git push && git push --tags
Wait for continuous integration to finish. Prebuilds will be generated for all supported platforms and attached to a Github release. Documentation is automatically generated and committed to gh-pages. Finally, a new NPM package version will be automatically released.
Version 6+ is a complete rewrite of previous versions of ZeroMQ.js in order to be more reliable, correct, and usable in modern JavaScript & TypeScript code as first outlined in this issue. Previous versions of ZeroMQ.js were based on zmq` and a fork that included prebuilt binaries.
See detailed changes in the CHANGELOG.