puppeteer/lib/Connection.js

216 lines
6.3 KiB
JavaScript
Raw Normal View History

/**
* Copyright 2017 Google Inc. 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
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
const debugProtocol = require('debug')('puppeteer:protocol');
const debugSession = require('debug')('puppeteer:session');
2017-08-02 19:06:47 +00:00
const EventEmitter = require('events');
const WebSocket = require('ws');
class Connection extends EventEmitter {
2017-06-21 20:51:06 +00:00
/**
* @param {string} url
* @param {number=} delay
* @return {!Promise<!Connection>}
*/
static async create(url, delay = 0) {
return new Promise((resolve, reject) => {
const ws = new WebSocket(url, { perMessageDeflate: false });
ws.on('open', () => resolve(new Connection(url, ws, delay)));
ws.on('error', reject);
});
}
/**
* @param {string} url
2017-06-21 20:58:49 +00:00
* @param {!WebSocket} ws
* @param {number=} delay
2017-06-21 20:58:49 +00:00
*/
constructor(url, ws, delay = 0) {
2017-06-21 20:51:06 +00:00
super();
this._url = url;
2017-06-21 20:51:06 +00:00
this._lastId = 0;
/** @type {!Map<number, {resolve: function, reject: function, method: string}>}*/
2017-06-21 20:51:06 +00:00
this._callbacks = new Map();
this._delay = delay;
2017-06-21 20:51:06 +00:00
this._ws = ws;
this._ws.on('message', this._onMessage.bind(this));
this._ws.on('close', this._onClose.bind(this));
/** @type {!Map<string, !Session>}*/
this._sessions = new Map();
}
/**
* @return {string}
*/
url() {
return this._url;
}
2017-06-21 20:51:06 +00:00
/**
2017-06-21 20:58:49 +00:00
* @param {string} method
* @param {!Object=} params
2017-06-21 20:58:49 +00:00
* @return {!Promise<?Object>}
*/
2017-06-21 20:51:06 +00:00
send(method, params = {}) {
const id = ++this._lastId;
const message = JSON.stringify({id, method, params});
debugProtocol('SEND ► ' + message);
2017-06-21 20:51:06 +00:00
this._ws.send(message);
return new Promise((resolve, reject) => {
this._callbacks.set(id, {resolve, reject, method});
});
}
2017-06-21 20:51:06 +00:00
/**
2017-06-21 20:58:49 +00:00
* @param {string} message
*/
async _onMessage(message) {
if (this._delay)
await new Promise(f => setTimeout(f, this._delay));
debugProtocol('◀ RECV ' + message);
const object = JSON.parse(message);
2017-06-21 20:51:06 +00:00
if (object.id && this._callbacks.has(object.id)) {
const callback = this._callbacks.get(object.id);
2017-06-21 20:51:06 +00:00
this._callbacks.delete(object.id);
if (object.error)
callback.reject(new Error(`Protocol error (${callback.method}): ${object.error.message} ${object.error.data}`));
2017-06-21 20:51:06 +00:00
else
callback.resolve(object.result);
} else {
console.assert(!object.id);
if (object.method === 'Target.receivedMessageFromTarget') {
const session = this._sessions.get(object.params.sessionId);
if (session)
session._onMessage(object.params.message);
} else if (object.method === 'Target.detachedFromTarget') {
const session = this._sessions.get(object.params.sessionId);
if (session)
session._onClosed();
this._sessions.delete(object.params.sessionId);
} else {
this.emit(object.method, object.params);
}
}
2017-06-21 20:51:06 +00:00
}
2017-06-21 20:51:06 +00:00
_onClose() {
this._ws.removeAllListeners();
for (const callback of this._callbacks.values())
callback.reject(new Error(`Protocol error (${callback.method}): Target closed.`));
this._callbacks.clear();
for (const session of this._sessions.values())
session._onClosed();
this._sessions.clear();
2017-06-21 20:51:06 +00:00
}
dispose() {
this._onClose();
this._ws.close();
}
/**
* @param {string} targetId
* @return {!Promise<!Session>}
*/
async createSession(targetId) {
const {sessionId} = await this.send('Target.attachToTarget', {targetId});
const session = new Session(this, targetId, sessionId);
this._sessions.set(sessionId, session);
return session;
2017-06-21 20:51:06 +00:00
}
}
class Session extends EventEmitter {
/**
* @param {!Connection} connection
* @param {string} targetId
* @param {string} sessionId
*/
constructor(connection, targetId, sessionId) {
super();
this._lastId = 0;
/** @type {!Map<number, {resolve: function, reject: function, method: string}>}*/
this._callbacks = new Map();
this._connection = connection;
this._targetId = targetId;
this._sessionId = sessionId;
}
/**
* @return {string}
*/
targetId() {
return this._targetId;
}
/**
* @param {string} method
* @param {!Object=} params
* @return {!Promise<?Object>}
*/
send(method, params = {}) {
if (!this._connection)
return Promise.reject(new Error(`Protocol error (${method}): Session closed. Most likely the page has been closed.`));
const id = ++this._lastId;
const message = JSON.stringify({id, method, params});
debugSession('SEND ► ' + message);
this._connection.send('Target.sendMessageToTarget', {sessionId: this._sessionId, message}).catch(e => {
// The response from target might have been already dispatched.
if (!this._callbacks.has(id))
return;
const callback = this._callbacks.get(id);
this._callbacks.delete(id);
callback.reject(e);
});
return new Promise((resolve, reject) => {
this._callbacks.set(id, {resolve, reject, method});
});
}
/**
* @param {string} message
*/
_onMessage(message) {
debugSession('◀ RECV ' + message);
const object = JSON.parse(message);
if (object.id && this._callbacks.has(object.id)) {
const callback = this._callbacks.get(object.id);
this._callbacks.delete(object.id);
if (object.error)
callback.reject(new Error(`Protocol error (${callback.method}): ${object.error.message} ${object.error.data}`));
else
callback.resolve(object.result);
} else {
console.assert(!object.id);
this.emit(object.method, object.params);
}
}
async dispose() {
await this._connection.send('Target.closeTarget', {targetId: this._targetId});
}
_onClosed() {
for (const callback of this._callbacks.values())
callback.reject(new Error(`Protocol error (${callback.method}): Target closed.`));
this._callbacks.clear();
this._connection = null;
}
}
module.exports = {Connection, Session};