+++ /dev/null
-# ws: a Node.js WebSocket library
-
-[](https://www.npmjs.com/package/ws)
-[](https://travis-ci.org/websockets/ws)
-[](https://ci.appveyor.com/project/lpinca/ws)
-[](https://coveralls.io/r/websockets/ws?branch=master)
-
-ws is a simple to use, blazing fast, and thoroughly tested WebSocket client
-and server implementation.
-
-Passes the quite extensive Autobahn test suite: [server][server-report],
-[client][client-report].
-
-**Note**: This module does not work in the browser. The client in the docs is a
-reference to a back end with the role of a client in the WebSocket
-communication. Browser clients must use the native
-[`WebSocket`](https://developer.mozilla.org/en-US/docs/Web/API/WebSocket) object.
-To make the same code work seamlessly on Node.js and the browser, you can use
-one of the many wrappers available on npm, like
-[isomorphic-ws](https://github.com/heineiuo/isomorphic-ws).
-
-## Table of Contents
-
-* [Protocol support](#protocol-support)
-* [Installing](#installing)
- + [Opt-in for performance and spec compliance](#opt-in-for-performance-and-spec-compliance)
-* [API docs](#api-docs)
-* [WebSocket compression](#websocket-compression)
-* [Usage examples](#usage-examples)
- + [Sending and receiving text data](#sending-and-receiving-text-data)
- + [Sending binary data](#sending-binary-data)
- + [Simple server](#simple-server)
- + [External HTTP/S server](#external-https-server)
- + [Multiple servers sharing a single HTTP/S server](#multiple-servers-sharing-a-single-https-server)
- + [Server broadcast](#server-broadcast)
- + [echo.websocket.org demo](#echowebsocketorg-demo)
- + [Other examples](#other-examples)
-* [Error handling best practices](#error-handling-best-practices)
-* [FAQ](#faq)
- + [How to get the IP address of the client?](#how-to-get-the-ip-address-of-the-client)
- + [How to detect and close broken connections?](#how-to-detect-and-close-broken-connections)
- + [How to connect via a proxy?](#how-to-connect-via-a-proxy)
-* [Changelog](#changelog)
-* [License](#license)
-
-## Protocol support
-
-* **HyBi drafts 07-12** (Use the option `protocolVersion: 8`)
-* **HyBi drafts 13-17** (Current default, alternatively option `protocolVersion: 13`)
-
-## Installing
-
-```
-npm install --save ws
-```
-
-### Opt-in for performance and spec compliance
-
-There are 2 optional modules that can be installed along side with the ws
-module. These modules are binary addons which improve certain operations.
-Prebuilt binaries are available for the most popular platforms so you don't
-necessarily need to have a C++ compiler installed on your machine.
-
-- `npm install --save-optional bufferutil`: Allows to efficiently perform
- operations such as masking and unmasking the data payload of the WebSocket
- frames.
-- `npm install --save-optional utf-8-validate`: Allows to efficiently check
- if a message contains valid UTF-8 as required by the spec.
-
-## API docs
-
-See [`/doc/ws.md`](./doc/ws.md) for Node.js-like docs for the ws classes.
-
-## WebSocket compression
-
-ws supports the [permessage-deflate extension][permessage-deflate] which
-enables the client and server to negotiate a compression algorithm and its
-parameters, and then selectively apply it to the data payloads of each
-WebSocket message.
-
-The extension is disabled by default on the server and enabled by default on
-the client. It adds a significant overhead in terms of performance and memory
-consumption so we suggest to enable it only if it is really needed.
-
-Note that Node.js has a variety of issues with high-performance compression,
-where increased concurrency, especially on Linux, can lead to
-[catastrophic memory fragmentation][node-zlib-bug] and slow performance.
-If you intend to use permessage-deflate in production, it is worthwhile to set
-up a test representative of your workload and ensure Node.js/zlib will handle
-it with acceptable performance and memory usage.
-
-Tuning of permessage-deflate can be done via the options defined below. You can
-also use `zlibDeflateOptions` and `zlibInflateOptions`, which is passed directly
-into the creation of [raw deflate/inflate streams][node-zlib-deflaterawdocs].
-
-See [the docs][ws-server-options] for more options.
-
-```js
-const WebSocket = require('ws');
-
-const wss = new WebSocket.Server({
- port: 8080,
- perMessageDeflate: {
- zlibDeflateOptions: { // See zlib defaults.
- chunkSize: 1024,
- memLevel: 7,
- level: 3,
- },
- zlibInflateOptions: {
- chunkSize: 10 * 1024
- },
- // Other options settable:
- clientNoContextTakeover: true, // Defaults to negotiated value.
- serverNoContextTakeover: true, // Defaults to negotiated value.
- clientMaxWindowBits: 10, // Defaults to negotiated value.
- serverMaxWindowBits: 10, // Defaults to negotiated value.
- // Below options specified as default values.
- concurrencyLimit: 10, // Limits zlib concurrency for perf.
- threshold: 1024, // Size (in bytes) below which messages
- // should not be compressed.
- }
-});
-```
-
-The client will only use the extension if it is supported and enabled on the
-server. To always disable the extension on the client set the
-`perMessageDeflate` option to `false`.
-
-```js
-const WebSocket = require('ws');
-
-const ws = new WebSocket('ws://www.host.com/path', {
- perMessageDeflate: false
-});
-```
-
-## Usage examples
-
-### Sending and receiving text data
-
-```js
-const WebSocket = require('ws');
-
-const ws = new WebSocket('ws://www.host.com/path');
-
-ws.on('open', function open() {
- ws.send('something');
-});
-
-ws.on('message', function incoming(data) {
- console.log(data);
-});
-```
-
-### Sending binary data
-
-```js
-const WebSocket = require('ws');
-
-const ws = new WebSocket('ws://www.host.com/path');
-
-ws.on('open', function open() {
- const array = new Float32Array(5);
-
- for (var i = 0; i < array.length; ++i) {
- array[i] = i / 2;
- }
-
- ws.send(array);
-});
-```
-
-### Simple server
-
-```js
-const WebSocket = require('ws');
-
-const wss = new WebSocket.Server({ port: 8080 });
-
-wss.on('connection', function connection(ws) {
- ws.on('message', function incoming(message) {
- console.log('received: %s', message);
- });
-
- ws.send('something');
-});
-```
-
-### External HTTP/S server
-
-```js
-const fs = require('fs');
-const https = require('https');
-const WebSocket = require('ws');
-
-const server = new https.createServer({
- cert: fs.readFileSync('/path/to/cert.pem'),
- key: fs.readFileSync('/path/to/key.pem')
-});
-const wss = new WebSocket.Server({ server });
-
-wss.on('connection', function connection(ws) {
- ws.on('message', function incoming(message) {
- console.log('received: %s', message);
- });
-
- ws.send('something');
-});
-
-server.listen(8080);
-```
-
-### Multiple servers sharing a single HTTP/S server
-
-```js
-const http = require('http');
-const WebSocket = require('ws');
-
-const server = http.createServer();
-const wss1 = new WebSocket.Server({ noServer: true });
-const wss2 = new WebSocket.Server({ noServer: true });
-
-wss1.on('connection', function connection(ws) {
- // ...
-});
-
-wss2.on('connection', function connection(ws) {
- // ...
-});
-
-server.on('upgrade', function upgrade(request, socket, head) {
- const pathname = url.parse(request.url).pathname;
-
- if (pathname === '/foo') {
- wss1.handleUpgrade(request, socket, head, function done(ws) {
- wss1.emit('connection', ws, request);
- });
- } else if (pathname === '/bar') {
- wss2.handleUpgrade(request, socket, head, function done(ws) {
- wss2.emit('connection', ws, request);
- });
- } else {
- socket.destroy();
- }
-});
-
-server.listen(8080);
-```
-
-### Server broadcast
-
-```js
-const WebSocket = require('ws');
-
-const wss = new WebSocket.Server({ port: 8080 });
-
-// Broadcast to all.
-wss.broadcast = function broadcast(data) {
- wss.clients.forEach(function each(client) {
- if (client.readyState === WebSocket.OPEN) {
- client.send(data);
- }
- });
-};
-
-wss.on('connection', function connection(ws) {
- ws.on('message', function incoming(data) {
- // Broadcast to everyone else.
- wss.clients.forEach(function each(client) {
- if (client !== ws && client.readyState === WebSocket.OPEN) {
- client.send(data);
- }
- });
- });
-});
-```
-
-### echo.websocket.org demo
-
-```js
-const WebSocket = require('ws');
-
-const ws = new WebSocket('wss://echo.websocket.org/', {
- origin: 'https://websocket.org'
-});
-
-ws.on('open', function open() {
- console.log('connected');
- ws.send(Date.now());
-});
-
-ws.on('close', function close() {
- console.log('disconnected');
-});
-
-ws.on('message', function incoming(data) {
- console.log(`Roundtrip time: ${Date.now() - data} ms`);
-
- setTimeout(function timeout() {
- ws.send(Date.now());
- }, 500);
-});
-```
-
-### Other examples
-
-For a full example with a browser client communicating with a ws server, see the
-examples folder.
-
-Otherwise, see the test cases.
-
-## Error handling best practices
-
-```js
-// If the WebSocket is closed before the following send is attempted
-ws.send('something');
-
-// Errors (both immediate and async write errors) can be detected in an optional
-// callback. The callback is also the only way of being notified that data has
-// actually been sent.
-ws.send('something', function ack(error) {
- // If error is not defined, the send has been completed, otherwise the error
- // object will indicate what failed.
-});
-
-// Immediate errors can also be handled with `try...catch`, but **note** that
-// since sends are inherently asynchronous, socket write failures will *not* be
-// captured when this technique is used.
-try { ws.send('something'); }
-catch (e) { /* handle error */ }
-```
-
-## FAQ
-
-### How to get the IP address of the client?
-
-The remote IP address can be obtained from the raw socket.
-
-```js
-const WebSocket = require('ws');
-
-const wss = new WebSocket.Server({ port: 8080 });
-
-wss.on('connection', function connection(ws, req) {
- const ip = req.connection.remoteAddress;
-});
-```
-
-When the server runs behind a proxy like NGINX, the de-facto standard is to use
-the `X-Forwarded-For` header.
-
-```js
-wss.on('connection', function connection(ws, req) {
- const ip = req.headers['x-forwarded-for'].split(/\s*,\s*/)[0];
-});
-```
-
-### How to detect and close broken connections?
-
-Sometimes the link between the server and the client can be interrupted in a
-way that keeps both the server and the client unaware of the broken state of the
-connection (e.g. when pulling the cord).
-
-In these cases ping messages can be used as a means to verify that the remote
-endpoint is still responsive.
-
-```js
-const WebSocket = require('ws');
-
-const wss = new WebSocket.Server({ port: 8080 });
-
-function noop() {}
-
-function heartbeat() {
- this.isAlive = true;
-}
-
-wss.on('connection', function connection(ws) {
- ws.isAlive = true;
- ws.on('pong', heartbeat);
-});
-
-const interval = setInterval(function ping() {
- wss.clients.forEach(function each(ws) {
- if (ws.isAlive === false) return ws.terminate();
-
- ws.isAlive = false;
- ws.ping(noop);
- });
-}, 30000);
-```
-
-Pong messages are automatically sent in response to ping messages as required
-by the spec.
-
-### How to connect via a proxy?
-
-Use a custom `http.Agent` implementation like [https-proxy-agent][] or
-[socks-proxy-agent][].
-
-## Changelog
-
-We're using the GitHub [releases][changelog] for changelog entries.
-
-## License
-
-[MIT](LICENSE)
-
-[https-proxy-agent]: https://github.com/TooTallNate/node-https-proxy-agent
-[socks-proxy-agent]: https://github.com/TooTallNate/node-socks-proxy-agent
-[client-report]: http://websockets.github.io/ws/autobahn/clients/
-[server-report]: http://websockets.github.io/ws/autobahn/servers/
-[permessage-deflate]: https://tools.ietf.org/html/rfc7692
-[changelog]: https://github.com/websockets/ws/releases
-[node-zlib-bug]: https://github.com/nodejs/node/issues/8871
-[node-zlib-deflaterawdocs]: https://nodejs.org/api/zlib.html#zlib_zlib_createdeflateraw_options
-[ws-server-options]: https://github.com/websockets/ws/blob/master/doc/ws.md#new-websocketserveroptions-callback
projects / VSoRC / .git / blobdiff