Reconnecting WebSocket 源码分析
Reconnecting WebSocket 功能有
WebSocket,如果连接关闭,将自动重新连接。
重连之后会根据为啥送消息,重新发送给服务器等功能。
Reconnecting WebSocket 也是基于WebSocket 二次封装的,里面用到了订阅发版,队列等思想封装。
Features
-兼容WebSocket API(相同接口,Level0和Level2事件模型)
——完全可配置
-多平台(Web, ServiceWorkers, Node.js, React Native)
-无依赖(不依赖Window, DOM或任何EventEmitter库)
—处理连接超时
-允许更改服务器URL之间的重新连接
- - -缓冲。 将发送累积的信息打开
-多个版本可用(见dist文件夹)
——调试模式
Install
npm install --save reconnecting-websocket
使用
-
兼容WebSocket浏览器API
-
所以这个文档应该是有效的:
Simple usage
import ReconnectingWebSocket from 'reconnecting-websocket';
const rws = new ReconnectingWebSocket('ws://my.site.com');
rws.addEventListener('open', () => {
rws.send('hello!');
});
Update URL
The url
parameter will be resolved before connecting, possible types:
string
() => string
() => Promise<string>
import ReconnectingWebSocket from 'reconnecting-websocket';
const urls = ['ws://my.site.com', 'ws://your.site.com', 'ws://their.site.com'];
let urlIndex = 0;
// round robin url provider
const urlProvider = () => urls[urlIndex++ % urls.length];
const rws = new ReconnectingWebSocket(urlProvider);
import ReconnectingWebSocket from 'reconnecting-websocket';
// async url provider
const urlProvider = async () => {
const token = await getSessionToken();
return `wss://my.site.com/${token}`;
};
const rws = new ReconnectingWebSocket(urlProvider);
Options
Sample with custom options
import ReconnectingWebSocket from 'reconnecting-websocket';
import WS from 'ws';
const options = {
WebSocket: WS, // custom WebSocket constructor
connectionTimeout: 1000,
maxRetries: 10,
};
const rws = new ReconnectingWebSocket('ws://my.site.com', [], options);
Available options 参数选项
type Options = {
WebSocket?: any; // WebSocket构造函数,如果没有提供,默认为全局WebSocket
maxReconnectionDelay?: number; // 重连之间的最大延迟(ms)
minReconnectionDelay?: number; // 重连之间的最小延迟(ms) 连接上5000毫秒以上输入一个日志
reconnectionDelayGrowFactor?: number; // 重连接延迟增长的速度有多快 意思是每次都会增加1.3倍数
minUptime?: number; // 连接上5000毫秒以上输入一个日志 稳定连接上5000毫秒
connectionTimeout?: number; // 连接超时间
maxRetries?: number; // maximum number of retries // 最大重复连接次数
maxEnqueuedMessages?: number; // 在重新连接之前要缓冲区的最大消息数 最大的发送消息队列
startClosed?: boolean; //在关闭状态下启动websocket,调用' .reconnect() '连接
debug?: boolean; // enables debug output 使调试输出
};
Default values 默认参数
WebSocket: undefined,
maxReconnectionDelay: 10000,
minReconnectionDelay: 1000 + Math.random() * 4000,
reconnectionDelayGrowFactor: 1.3,
minUptime: 5000,
connectionTimeout: 4000,
maxRetries: Infinity,
maxEnqueuedMessages: Infinity,
startClosed: false,
debug: false,
API
Methods 方法
constructor(url: UrlProvider, protocols?: string | string[], options?: Options)
close(code?: number, reason?: string)
reconnect(code?: number, reason?: string)
send(data: string | ArrayBuffer | Blob | ArrayBufferView)
addEventListener(type: 'open' | 'close' | 'message' | 'error', listener: EventListener)
removeEventListener(type: 'open' | 'close' | 'message' | 'error', listener: EventListener)
Attributes 属性
binaryType: string;
bufferedAmount: number;
extensions: string;
onclose: EventListener;
onerror: EventListener;
onmessage: EventListener;
onopen: EventListener;
protocol: string;
readyState: number;
url: string;
retryCount: number;
Constants 连接状态
CONNECTING 0 The connection is not yet open.
OPEN 1 The connection is open and ready to communicate.
CLOSING 2 The connection is in the process of closing.
CLOSED 3 The connection is closed or couldn't be opened.
逐行源码分析
'use strict';
/*! *****************************************************************************
Copyright (c) Microsoft Corporation. All rights reserved.
Licensed under the Apache License, Version 2.0 (the "License"); you may not use
this file except in compliance with the License. You may obtain a copy of the
License at http://www.apache.org/licenses/LICENSE-2.0
THIS CODE IS PROVIDED ON AN *AS IS* BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
KIND, EITHER EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION ANY IMPLIED
WARRANTIES OR CONDITIONS OF TITLE, FITNESS FOR A PARTICULAR PURPOSE,
MERCHANTABLITY OR NON-INFRINGEMENT.
See the Apache Version 2.0 License for specific language governing permissions
and limitations under the License.
***************************************************************************** */
/* global Reflect, Promise */
var extendStatics = function (d, b) {
extendStatics = Object.setPrototypeOf ||
({ __proto__: [] } instanceof Array && function (d, b) { d.__proto__ = b; }) ||
function (d, b) { for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p]; };
return extendStatics(d, b);
};
function __extends (d, b) {
extendStatics(d, b);
function __ () { this.constructor = d; }
d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
}
function __values (o) {
var m = typeof Symbol === "function" && o[Symbol.iterator], i = 0;
if (m) return m.call(o);
return {
next: function () {
if (o && i >= o.length) o = void 0;
return { value: o && o[i++], done: !o };
}
};
}
function __read (o, n) {
var m = typeof Symbol === "function" && o[Symbol.iterator];
if (!m) return o;
var i = m.call(o), r, ar = [], e;
try {
while ((n === void 0 || n-- > 0) && !(r = i.next()).done) ar.push(r.value);
}
catch (error) { e = { error: error }; }
finally {
try {
if (r && !r.done && (m = i["return"])) m.call(i);
}
finally { if (e) throw e.error; }
}
return ar;
}
function __spread () {
for (var ar = [], i = 0; i < arguments.length; i++)
ar = ar.concat(__read(arguments[i]));
return ar;
}
var Event = /** @class */ (function () {
function Event (type, target) {
this.target = target;
this.type = type;
}
return Event;
}());
var ErrorEvent = /** @class */ (function (_super) {
__extends(ErrorEvent, _super);
function ErrorEvent (error, target) {
var _this = _super.call(this, 'error', target) || this;
_this.message = error.message;
_this.error = error;
return _this;
}
return ErrorEvent;
}(Event));
var CloseEvent = /** @class */ (function (_super) {
__extends(CloseEvent, _super);
function CloseEvent (code, reason, target) {
if (code === void 0) { code = 1000; }
if (reason === void 0) { reason = ''; }
var _this = _super.call(this, 'close', target) || this;
_this.wasClean = true;
_this.code = code;
_this.reason = reason;
return _this;
}
return CloseEvent;
}(Event));
/*!
* Reconnecting WebSocket
* by Pedro Ladaria <pedro.ladaria@gmail.com>
* https://github.com/pladaria/reconnecting-websocket
* License MIT
*/
var getGlobalWebSocket = function () {
if (typeof WebSocket !== 'undefined') {
// @ts-ignore
return WebSocket;
}
};
/**
* Returns true if given argument looks like a WebSocket class
*/
var isWebSocket = function (w) { return typeof w !== 'undefined' && !!w && w.CLOSING === 2; };
var DEFAULT = {
maxReconnectionDelay: 10000, // 最大的重连时间
minReconnectionDelay: 1000 + Math.random() * 4000, // 重连 时间间隔
minUptime: 5000, // 连接上5000毫秒以上输入一个日志
reconnectionDelayGrowFactor: 1.3, // 重连接延迟增长的速度有多快 意思是每次都会增加1.3倍数
connectionTimeout: 4000, // 连接超时
maxRetries: Infinity, // 最大重复连接次数
maxEnqueuedMessages: Infinity, // 最大的发送消息队列
startClosed: false, // 在关闭状态下启动websocket,调用' .reconnect() '连接
debug: false, // 是否输出日志
};
var ReconnectingWebSocket = /** @class */ (function () {
function ReconnectingWebSocket (
url, // 地址
protocols,
options // 拓展参数
) {
var _this = this;
if (options === void 0) { options = {}; }
this._listeners = {
error: [],
message: [],
open: [],
close: [],
};
this._retryCount = -1;
this._shouldReconnect = true;
this._connectLock = false;
this._binaryType = 'blob';
this._closeCalled = false;
this._messageQueue = [];
/**
* An event listener to be called when the WebSocket connection's readyState changes to CLOSED
*/
this.onclose = null; // 关闭回调函数
/**
* An event listener to be called when an error occurs
*/
this.onerror = null; // 错误回调函数
/**
* An event listener to be called when a message is received from the server
*/
this.onmessage = null; // 发送信息回调函数
/**
* An event listener to be called when the WebSocket connection's readyState changes to OPEN;
* this indicates that the connection is ready to send and receive data
*/
this.onopen = null;
//WebSocket 连接 open 方法
this._handleOpen = function (
event //WebSocket 事件
) {
_this._debug('open event');
var _a = _this._options.minUptime,
minUptime = _a === void 0 ? DEFAULT.minUptime : _a;
// 清除 连接超时定时器
clearTimeout(_this._connectTimeout);
_this._uptimeTimeout = setTimeout(function () {
return _this._acceptOpen();
}, minUptime);
_this._ws.binaryType = _this._binaryType;
// send enqueued messages (messages sent before websocket open event)
/*发送排队的消息(在websocket打开事件之前发送的消息)
这种情况就是在发生网络突然断开之后,用发送信息未能发送个服务器,然后先存到一个队列中
等有网的时候连接上了再从队列中获取消息发送给服务器
*/
_this._messageQueue.forEach(function (message) {
// 给服务器发送信息
return _this._ws.send(message);
});
// 清空队列
_this._messageQueue = [];
// 连接上回调方法
if (_this.onopen) {
_this.onopen(event);
}
//实例化对象连接注册事件
_this._listeners.open.forEach(function (listener) {
return _this._callEventListener(event, listener);
});
};
// WebSocket发送Message 方法
this._handleMessage = function (event) {
_this._debug('message event');
if (_this.onmessage) {
_this.onmessage(event);
}
//
_this._listeners.message.forEach(function (listener) {
return _this._callEventListener(event, listener);
});
};
// WebSocket Error 方法
this._handleError = function (event) {
_this._debug('error event', event.message);
_this._disconnect(undefined, event.message === 'TIMEOUT' ? 'timeout' : undefined);
if (_this.onerror) {
_this.onerror(event);
}
_this._debug('exec error listeners');
_this._listeners.error.forEach(function (listener) {
return _this._callEventListener(event, listener);
});
_this._connect();
};
// WebSocket Close 方法
this._handleClose = function (event) {
_this._debug('close event');
_this._clearTimeouts();
if (_this._shouldReconnect) {
_this._connect();
}
if (_this.onclose) {
_this.onclose(event);
}
_this._listeners.close.forEach(function (listener) { return _this._callEventListener(event, listener); });
};
// 连接地址
this._url = url;
this._protocols = protocols;
this._options = options;
if (this._options.startClosed) {
this._shouldReconnect = false;
}
// 连接WebSocket
this._connect();
}
// 0
Object.defineProperty(ReconnectingWebSocket, "CONNECTING", {
get: function () {
return 0;
},
enumerable: true,
configurable: true
});
// 1
Object.defineProperty(ReconnectingWebSocket, "OPEN", {
get: function () {
return 1;
},
enumerable: true,
configurable: true
});
//2
Object.defineProperty(ReconnectingWebSocket, "CLOSING", {
get: function () {
return 2;
},
enumerable: true,
configurable: true
});
//3
Object.defineProperty(ReconnectingWebSocket, "CLOSED", {
get: function () {
return 3;
},
enumerable: true,
configurable: true
});
// 0
Object.defineProperty(ReconnectingWebSocket.prototype, "CONNECTING", {
get: function () {
return ReconnectingWebSocket.CONNECTING;
},
enumerable: true,
configurable: true
});
//1
Object.defineProperty(ReconnectingWebSocket.prototype, "OPEN", {
get: function () {
return ReconnectingWebSocket.OPEN;
},
enumerable: true,
configurable: true
});
//2
Object.defineProperty(ReconnectingWebSocket.prototype, "CLOSING", {
get: function () {
return ReconnectingWebSocket.CLOSING;
},
enumerable: true,
configurable: true
});
//3
Object.defineProperty(ReconnectingWebSocket.prototype, "CLOSED", {
get: function () {
return ReconnectingWebSocket.CLOSED;
},
enumerable: true,
configurable: true
});
// 使用二进制连接
Object.defineProperty(ReconnectingWebSocket.prototype, "binaryType", {
get: function () {
return this._ws ? this._ws.binaryType : this._binaryType;
},
set: function (value) {
this._binaryType = value;
if (this._ws) {
this._ws.binaryType = value;
}
},
enumerable: true,
configurable: true
});
// 重复连接次数
Object.defineProperty(ReconnectingWebSocket.prototype, "retryCount", {
/**
* Returns the number or connection retries
*/
get: function () {
return Math.max(this._retryCount, 0);
},
enumerable: true,
configurable: true
});
// 未发送至服务器的字节数。
Object.defineProperty(ReconnectingWebSocket.prototype, "bufferedAmount", {
/**
* The number of bytes of data that have been queued using calls to send() but not yet
* transmitted to the network. This value resets to zero once all queued data has been sent.
* This value does not reset to zero when the connection is closed; if you keep calling send(),
* this will continue to climb. Read only
*/
get: function () {
var bytes = this._messageQueue.reduce(function (acc, message) {
if (typeof message === 'string') {
acc += message.length; // not byte size
}
else if (message instanceof Blob) {
acc += message.size;
}
else {
acc += message.byteLength;
}
return acc;
}, 0);
return bytes + (this._ws ? this._ws.bufferedAmount : 0);
},
enumerable: true,
configurable: true
});
// 服务器选择的扩展。
Object.defineProperty(ReconnectingWebSocket.prototype, "extensions", {
/**
* The extensions selected by the server. This is currently only the empty string or a list of
* extensions as negotiated by the connection
*/
get: function () {
return this._ws ? this._ws.extensions : '';
},
enumerable: true,
configurable: true
});
// 服务器选择的下属协议。
Object.defineProperty(ReconnectingWebSocket.prototype, "protocol", {
/**
* A string indicating the name of the sub-protocol the server selected;
* this will be one of the strings specified in the protocols parameter when creating the
* WebSocket object
*/
get: function () {
return this._ws ? this._ws.protocol : '';
},
enumerable: true,
configurable: true
});
// 连接状态
Object.defineProperty(ReconnectingWebSocket.prototype, "readyState", {
/**
* The current state of the connection; this is one of the Ready state constants
*/
get: function () {
if (this._ws) {
return this._ws.readyState;
}
return this._options.startClosed
? ReconnectingWebSocket.CLOSED
: ReconnectingWebSocket.CONNECTING;
},
enumerable: true,
configurable: true
});
// 连接地址
Object.defineProperty(ReconnectingWebSocket.prototype, "url", {
/**
* The URL as resolved by the constructor
*/
get: function () {
return this._ws ? this._ws.url : '';
},
enumerable: true,
configurable: true
});
/**
* Closes the WebSocket connection or connection attempt, if any. If the connection is already
* CLOSED, this method does nothing
*/
// WebSocket关闭回调函数
ReconnectingWebSocket.prototype.close = function (code, reason) {
if (code === void 0) { code = 1000; }
this._closeCalled = true;
this._shouldReconnect = false;
this._clearTimeouts();
if (!this._ws) {
this._debug('close enqueued: no ws instance');
return;
}
if (this._ws.readyState === this.CLOSED) {
this._debug('close: already closed');
return;
}
this._ws.close(code, reason);
};
/**
* Closes the WebSocket connection or connection attempt and connects again.
* Resets retry counter;
* *关闭WebSocket连接或连接尝试,然后重新连接。
*重置重试计数器;
*
*/
//
ReconnectingWebSocket.prototype.reconnect = function (code, reason) {
this._shouldReconnect = true;
this._closeCalled = false;
this._retryCount = -1;
if (!this._ws || this._ws.readyState === this.CLOSED) {
this._connect();
}
else {
this._disconnect(code, reason);
this._connect();
}
};
/**
* Enqueue specified data to be transmitted to the server over the WebSocket connection
* 将要通过WebSocket连接传输到服务器的指定数据放入队列
*/
ReconnectingWebSocket.prototype.send = function (data) {
if (this._ws && this._ws.readyState === this.OPEN) {
this._debug('send', data);
this._ws.send(data);
} else {
var _a = this._options.maxEnqueuedMessages,
maxEnqueuedMessages = _a === void 0 ? DEFAULT.maxEnqueuedMessages : _a;
if (this._messageQueue.length < maxEnqueuedMessages) {
this._debug('enqueue', data);
this._messageQueue.push(data);
}
}
};
/**
* Register an event handler of a specific event type
* 注册一个特定事件类型的事件处理器
* 实例化对象注册 事件
socket.addEventListener("open", function () {
statusSpan.innerHTML = "Connected";
element.style.backgroundColor = "white";
});
socket.addEventListener("open",{
handleEvent:function () {
statusSpan.innerHTML = "Connected";
element.style.backgroundColor = "white";
}
});
*/
ReconnectingWebSocket.prototype.addEventListener = function (type, listener) {
//
if (this._listeners[type]) {
// @ts-ignore
// 添加到一个队列中
this._listeners[type].push(listener);
}
};
//调度 事件
ReconnectingWebSocket.prototype.dispatchEvent = function (event) {
var e_1, _a;
var listeners = this._listeners[event.type];
if (listeners) {
try {
for (
var listeners_1 = __values(listeners),
listeners_1_1 = listeners_1.next();
!listeners_1_1.done;
listeners_1_1 = listeners_1.next()
) {
var listener = listeners_1_1.value;
this._callEventListener(event, listener);
}
} catch (e_1_1) {
e_1 = { error: e_1_1 };
} finally {
try {
if (listeners_1_1 && !listeners_1_1.done && (_a = listeners_1.return)) {
_a.call(listeners_1);
}
} finally {
if (e_1) {
throw e_1.error;
}
}
}
}
return true;
};
/**
* Removes an event listener 删除事件监听器
*/
ReconnectingWebSocket.prototype.removeEventListener = function (type, listener) {
if (this._listeners[type]) {
// @ts-ignore
this._listeners[type] = this._listeners[type].filter(function (l) {
return l !== listener;
});
}
};
// 日志输出方法
ReconnectingWebSocket.prototype._debug = function () {
var args = [];
for (var _i = 0; _i < arguments.length; _i++) {
args[_i] = arguments[_i];
}
// 如果参数中需要打印日志
if (this._options.debug) {
// not using spread because compiled version uses Symbols
// tslint:disable-next-line
console.log.apply(console, __spread(['RWS>'], args));
}
};
// 根据重连次数而增加重连时长间隔
ReconnectingWebSocket.prototype._getNextDelay = function () {
var _a = this._options,
_b = _a.reconnectionDelayGrowFactor,
reconnectionDelayGrowFactor = _b === void 0 ? DEFAULT.reconnectionDelayGrowFactor : _b,
_c = _a.minReconnectionDelay,
minReconnectionDelay = _c === void 0 ? DEFAULT.minReconnectionDelay : _c, _d = _a.maxReconnectionDelay,
maxReconnectionDelay = _d === void 0 ? DEFAULT.maxReconnectionDelay : _d;
var delay = 0;
if (this._retryCount > 0) {
// 每次重连都会根据重连次数而增加重连时间 n 次方
delay = minReconnectionDelay * Math.pow(reconnectionDelayGrowFactor, this._retryCount - 1);
if (delay > maxReconnectionDelay) {
delay = maxReconnectionDelay;
}
}
this._debug('next delay', delay);
console.log('delay=======', delay)
return delay;
};
// 重连时间间隔设置
ReconnectingWebSocket.prototype._wait = function () {
var _this = this;
return new Promise(function (resolve) {
// 根据重连次数而增加重连时长间隔
setTimeout(resolve, _this._getNextDelay());
});
};
// 获取地址 可以是函数或者字符串
ReconnectingWebSocket.prototype._getNextUrl = function (urlProvider) {
if (typeof urlProvider === 'string') {
return Promise.resolve(urlProvider);
}
if (typeof urlProvider === 'function') {
var url = urlProvider();
if (typeof url === 'string') {
return Promise.resolve(url);
}
if (!!url.then) {
return url;
}
}
throw Error('Invalid URL');
};
//WebSocket 连接 方法
ReconnectingWebSocket.prototype._connect = function () {
var _this = this;
// 如果有连接则不在连接
if (this._connectLock || !this._shouldReconnect) {
return;
}
this._connectLock = true;
var _a = this._options,
_b = _a.maxRetries,
maxRetries = _b === void 0 ? DEFAULT.maxRetries : _b, _c = _a.connectionTimeout,
connectionTimeout = _c === void 0 ? DEFAULT.connectionTimeout : _c,
// options中的 WebSocket
_d = _a.WebSocket,
// 获取 WebSocket
WebSocket = _d === void 0 ? getGlobalWebSocket() : _d;
// 重复最大连接数
if (this._retryCount >= maxRetries) {
this._debug('max retries reached', this._retryCount, '>=', maxRetries);
return;
}
this._retryCount++;
this._debug('connect', this._retryCount);
// 删除WebSocket事件
this._removeListeners();
if (!isWebSocket(WebSocket)) {
throw Error('No valid WebSocket class provided');
}
// 重连时间间隔设置
this._wait()
.then(function () {
// 获取连接地址可以是字符串或者函数
return _this._getNextUrl(_this._url);
})
.then(function (
url // 获取连接地址
) {
// close could be called before creating the ws
// 可以在创建ws之前调用Close
if (_this._closeCalled) {
return;
}
// 日志
_this._debug('connect', { url: url, protocols: _this._protocols });
// WebSocket 实例
_this._ws = _this._protocols
? new WebSocket(url, _this._protocols)
: new WebSocket(url);
//使用二进制的数据类型连接。
_this._ws.binaryType = _this._binaryType;
_this._connectLock = false;
// 添加回调方法
_this._addListeners();
console.log('connectionTimeout=', connectionTimeout)
// 连接时长
_this._connectTimeout = setTimeout(
function () {
// 如果在连接设置超时时间没有连上则会报错
return _this._handleTimeout();
}, connectionTimeout
);
});
};
// 如果在连接设置超时时间没有连上则会报错
ReconnectingWebSocket.prototype._handleTimeout = function () {
this._debug('timeout event');
this._handleError(new ErrorEvent(Error('TIMEOUT'), this));
};
// 断开连接
ReconnectingWebSocket.prototype._disconnect = function (code, reason) {
if (code === void 0) { code = 1000; }
this._clearTimeouts();
if (!this._ws) {
return;
}
this._removeListeners();
try {
this._ws.close(code, reason);
this._handleClose(new CloseEvent(code, reason, this));
}
catch (error) {
// ignore
}
};
// 已连接了多久
ReconnectingWebSocket.prototype._acceptOpen = function () {
this._debug('accept open');
this._retryCount = 0;
};
//触发 ReconnectingWebSocket 实例化 回调函数
ReconnectingWebSocket.prototype._callEventListener = function (event, listener) {
console.log('event=', event)
// 如果是listener.handleEvent 执行回调方法 把 websocket 事件回调传进去
if ('handleEvent' in listener) {
// @ts-ignore
listener.handleEvent(event);
} else {
// @ts-ignore
//执行回调方法 把 websocket 事件回调传进去
listener(event);
}
};
// 删除WebSocket连接事件
ReconnectingWebSocket.prototype._removeListeners = function () {
if (!this._ws) {
return;
}
this._debug('removeListeners');
// 删除WebSocket连接事件
this._ws.removeEventListener('open', this._handleOpen);
this._ws.removeEventListener('close', this._handleClose);
this._ws.removeEventListener('message', this._handleMessage);
// @ts-ignore
this._ws.removeEventListener('error', this._handleError);
};
// 添加WebSocket响应方法
ReconnectingWebSocket.prototype._addListeners = function () {
if (!this._ws) {
return;
}
this._debug('addListeners');
// console.log('this._ws.addEventListener=',this._ws.addEventListener)
// websocket打开连接事件回调
this._ws.addEventListener('open', this._handleOpen);
// websocket关闭连接事件回调
this._ws.addEventListener('close', this._handleClose);
// websocket发送消息事件回调
this._ws.addEventListener('message', this._handleMessage);
//websocket连接错误事件回调 @ts-ignore 错误
this._ws.addEventListener('error', this._handleError);
};
// 清除定时器
ReconnectingWebSocket.prototype._clearTimeouts = function () {
clearTimeout(this._connectTimeout);
clearTimeout(this._uptimeTimeout);
};
return ReconnectingWebSocket;
}());
module.exports = ReconnectingWebSocket;
ReconnectingWebSocket类
通过ReconnectingWebSocket类 实现_handleOpen,_handleMessage,_handleError,_handleClose 方法。
绑定到WebSocket实例化对象中,通过_listeners 队列收集外部绑定的Open,Message,Error,Close方法,通过订阅发布思想把WebSocket方法中的回调函数调用Open,Message,Error,Close等方法把WebSocket响应传给他们。
断开消息队列重发机制
该ReconnectingWebSocket有断开以后可以记录用户需要重发的消息。我们看看他是如何做的。
先看看send方法,send方法是 判断WebSocket是否已经连接上,如果连接上直接发送, 如果没连接上先插入到一个消息队列中
/**
* Enqueue specified data to be transmitted to the server over the WebSocket connection
* 将要通过WebSocket连接传输到服务器的指定数据放入队列
*/
ReconnectingWebSocket.prototype.send = function (data) {
// 判断WebSocket是否已经连接上,如果连接上直接发送,
if (this._ws && this._ws.readyState === this.OPEN) {
this._debug('send', data);
this._ws.send(data);
} else {
// 如果没连接上先插入到一个消息队列中
var _a = this._options.maxEnqueuedMessages,
maxEnqueuedMessages = _a === void 0 ? DEFAULT.maxEnqueuedMessages : _a;
if (this._messageQueue.length < maxEnqueuedMessages) {
this._debug('enqueue', data);
this._messageQueue.push(data);
}
}
};
我们在来看看websocket连接上之后如何发送队列中的信息
//WebSocket 连接 open 方法
this._handleOpen = function (
event //WebSocket 事件
) {
_this._debug('open event');
var _a = _this._options.minUptime,
minUptime = _a === void 0 ? DEFAULT.minUptime : _a;
// 清除 连接超时定时器
clearTimeout(_this._connectTimeout);
_this._uptimeTimeout = setTimeout(function () {
return _this._acceptOpen();
}, minUptime);
_this._ws.binaryType = _this._binaryType;
// send enqueued messages (messages sent before websocket open event)
/*
发送排队的消息(在websocket打开事件之前发送的消息)
这种情况就是在发生网络突然断开之后,用发送信息未能发送个服务器,然后先存到一个队列中
等有网的时候连接上了再从队列中获取消息发送给服务器
*/
_this._messageQueue.forEach(function (message) {
// 给服务器发送信息
return _this._ws.send(message);
});
// 清空队列
_this._messageQueue = [];
// 连接上回调方法
if (_this.onopen) {
_this.onopen(event);
}
//实例化对象连接注册事件
_this._listeners.open.forEach(function (listener) {
return _this._callEventListener(event, listener);
});
};
我们看到 这里就就是连接上之后发送刚才websocket断开连接时候的消息循环messageQueue一条条的发送出去。
_this._messageQueue.forEach(function (message) {
// 给服务器发送信息
return _this._ws.send(message);
});
开源不容,希望大家给我点下star