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| author | ruki <waruqi@gmail.com> | 2018-11-08 00:38:48 +0800 |
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| committer | ruki <waruqi@gmail.com> | 2018-11-07 21:53:09 +0800 |
| commit | 26105034da4fcce7ac883c899d781f016559310d (patch) | |
| tree | c459a5dc4e3aa0972d9919033ece511ce76dd129 /node_modules/ws/README.md | |
| parent | 2c77f00f1a7ecb6c8192f9c16d3b2001b254a107 (diff) | |
| download | xmake-docs-26105034da4fcce7ac883c899d781f016559310d.tar.gz xmake-docs-26105034da4fcce7ac883c899d781f016559310d.zip | |
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diff --git a/node_modules/ws/README.md b/node_modules/ws/README.md new file mode 100644 index 00000000..8f94ca30 --- /dev/null +++ b/node_modules/ws/README.md @@ -0,0 +1,389 @@ +# 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) + + [Server example](#server-example) + + [Broadcast example](#broadcast-example) + + [ExpressJS example](#expressjs-example) + + [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); +}); +``` + +### Server example + +```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'); +}); +``` + +### Broadcast example + +```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); + } + }); + }); +}); +``` + +### ExpressJS example + +```js +const express = require('express'); +const http = require('http'); +const url = require('url'); +const WebSocket = require('ws'); + +const app = express(); + +app.use(function (req, res) { + res.send({ msg: "hello" }); +}); + +const server = http.createServer(app); +const wss = new WebSocket.Server({ server }); + +wss.on('connection', function connection(ws, req) { + const location = url.parse(req.url, true); + // You might use location.query.access_token to authenticate or share sessions + // or req.headers.cookie (see http://stackoverflow.com/a/16395220/151312) + + ws.on('message', function incoming(message) { + console.log('received: %s', message); + }); + + ws.send('something'); +}); + +server.listen(8080, function listening() { + console.log('Listening on %d', server.address().port); +}); +``` + +### 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']; +}); +``` + +### 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 |
