236 lines
7.0 KiB
Markdown
236 lines
7.0 KiB
Markdown
# ws: a node.js websocket library
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[](https://travis-ci.org/websockets/ws)
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`ws` is a simple to use WebSocket implementation, up-to-date against RFC-6455,
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and [probably the fastest WebSocket library for node.js][archive].
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Passes the quite extensive Autobahn test suite. See http://websockets.github.com/ws
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for the full reports.
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## Protocol support
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* **Hixie draft 76** (Old and deprecated, but still in use by Safari and Opera.
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Added to ws version 0.4.2, but server only. Can be disabled by setting the
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`disableHixie` option to true.)
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* **HyBi drafts 07-12** (Use the option `protocolVersion: 8`)
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* **HyBi drafts 13-17** (Current default, alternatively option `protocolVersion: 13`)
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### Installing
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```
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npm install --save ws
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```
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### Opt-in for performance
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There are 2 optional modules that can be installed along side with the `ws`
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module. These modules are binary addons which improve certain operations, but as
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they are binary addons they require compilation which can fail if no c++
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compiler is installed on the host system.
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- `npm install --save bufferutil`: Improves internal buffer operations which
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allows for faster processing of masked WebSocket frames and general buffer
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operations.
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- `npm install --save utf-8-validate`: The specification requires validation of
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invalid UTF-8 chars, some of these validations could not be done in JavaScript
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hence the need for a binary addon. In most cases you will already be
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validating the input that you receive for security purposes leading to double
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validation. But if you want to be 100% spec-conforming and have fast
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validation of UTF-8 then this module is a must.
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### Sending and receiving text data
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```js
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var WebSocket = require('ws');
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var ws = new WebSocket('ws://www.host.com/path');
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ws.on('open', function open() {
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ws.send('something');
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});
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ws.on('message', function(data, flags) {
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// flags.binary will be set if a binary data is received.
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// flags.masked will be set if the data was masked.
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});
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```
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### Sending binary data
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```js
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var WebSocket = require('ws');
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var ws = new WebSocket('ws://www.host.com/path');
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ws.on('open', function open() {
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var array = new Float32Array(5);
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for (var i = 0; i < array.length; ++i) {
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array[i] = i / 2;
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}
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ws.send(array, { binary: true, mask: true });
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});
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```
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Setting `mask`, as done for the send options above, will cause the data to be
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masked according to the WebSocket protocol. The same option applies for text
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data.
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### Server example
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```js
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var WebSocketServer = require('ws').Server
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, wss = new WebSocketServer({ port: 8080 });
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wss.on('connection', function connection(ws) {
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ws.on('message', function incoming(message) {
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console.log('received: %s', message);
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});
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ws.send('something');
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});
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```
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### ExpressJS example
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```js
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var server = require('http').createServer()
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, url = require('url')
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, WebSocketServer = require('ws').Server
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, wss = new WebSocketServer({ server: server })
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, express = require('express')
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, app = express()
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, port = 4080;
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app.use(function (req, res) {
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res.send({ msg: "hello" });
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});
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wss.on('connection', function connection(ws) {
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var location = url.parse(ws.upgradeReq.url, true);
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// you might use location.query.access_token to authenticate or share sessions
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// or ws.upgradeReq.headers.cookie (see http://stackoverflow.com/a/16395220/151312)
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ws.on('message', function incoming(message) {
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console.log('received: %s', message);
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});
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ws.send('something');
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});
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server.on('request', app);
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server.listen(port, function () { console.log('Listening on ' + server.address().port) });
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```
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### Server sending broadcast data
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```js
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var WebSocketServer = require('ws').Server
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, wss = new WebSocketServer({ port: 8080 });
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wss.broadcast = function broadcast(data) {
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wss.clients.forEach(function each(client) {
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client.send(data);
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});
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};
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```
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### Error handling best practices
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```js
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// If the WebSocket is closed before the following send is attempted
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ws.send('something');
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// Errors (both immediate and async write errors) can be detected in an optional
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// callback. The callback is also the only way of being notified that data has
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// actually been sent.
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ws.send('something', function ack(error) {
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// if error is not defined, the send has been completed,
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// otherwise the error object will indicate what failed.
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});
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// Immediate errors can also be handled with try/catch-blocks, but **note** that
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// since sends are inherently asynchronous, socket write failures will *not* be
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// captured when this technique is used.
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try { ws.send('something'); }
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catch (e) { /* handle error */ }
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```
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### echo.websocket.org demo
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```js
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var WebSocket = require('ws');
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var ws = new WebSocket('ws://echo.websocket.org/', {
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protocolVersion: 8,
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origin: 'http://websocket.org'
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});
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ws.on('open', function open() {
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console.log('connected');
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ws.send(Date.now().toString(), {mask: true});
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});
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ws.on('close', function close() {
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console.log('disconnected');
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});
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ws.on('message', function message(data, flags) {
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console.log('Roundtrip time: ' + (Date.now() - parseInt(data)) + 'ms', flags);
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setTimeout(function timeout() {
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ws.send(Date.now().toString(), {mask: true});
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}, 500);
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});
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```
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### Other examples
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For a full example with a browser client communicating with a ws server, see the
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examples folder.
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Note that the usage together with Express 3.0 is quite different from Express
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2.x. The difference is expressed in the two different serverstats-examples.
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Otherwise, see the test cases.
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### Running the tests
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```
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make test
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```
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## API Docs
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See [`/doc/ws.md`](https://github.com/websockets/ws/blob/master/doc/ws.md) for Node.js-like docs for the ws classes.
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## Changelog
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We're using the GitHub [`releases`](https://github.com/websockets/ws/releases) for changelog entries.
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## License
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(The MIT License)
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Copyright (c) 2011 Einar Otto Stangvik <einaros@gmail.com>
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Permission is hereby granted, free of charge, to any person obtaining
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a copy of this software and associated documentation files (the
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'Software'), to deal in the Software without restriction, including
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without limitation the rights to use, copy, modify, merge, publish,
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distribute, sublicense, and/or sell copies of the Software, and to
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permit persons to whom the Software is furnished to do so, subject to
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the following conditions:
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The above copyright notice and this permission notice shall be
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included in all copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND,
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EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
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IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
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CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
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TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
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SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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[archive]: http://web.archive.org/web/20130314230536/http://hobbycoding.posterous.com/the-fastest-websocket-module-for-nodejs
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