136 lines
3.8 KiB
JavaScript
136 lines
3.8 KiB
JavaScript
/*
|
|
* Copyright (C) 2019 Alex Yatskov <alex@foosoft.net>
|
|
* Author: Alex Yatskov <alex@foosoft.net>
|
|
*
|
|
* This program is free software: you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation, either version 3 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
|
|
class FrontendApiSender {
|
|
constructor() {
|
|
this.senderId = FrontendApiSender.generateId(16);
|
|
this.ackTimeout = 3000; // 3 seconds
|
|
this.responseTimeout = 10000; // 10 seconds
|
|
this.callbacks = {};
|
|
this.disconnected = false;
|
|
this.nextId = 0;
|
|
|
|
this.port = null;
|
|
}
|
|
|
|
invoke(action, params, target) {
|
|
if (this.disconnected) {
|
|
return Promise.reject('Disconnected');
|
|
}
|
|
|
|
if (this.port === null) {
|
|
this.createPort();
|
|
}
|
|
|
|
const id = `${this.nextId}`;
|
|
++this.nextId;
|
|
|
|
return new Promise((resolve, reject) => {
|
|
const info = {id, resolve, reject, ack: false, timer: null};
|
|
this.callbacks[id] = info;
|
|
info.timer = setTimeout(() => this.onError(id, 'Timeout (ack)'), this.ackTimeout);
|
|
|
|
this.port.postMessage({id, action, params, target, senderId: this.senderId});
|
|
});
|
|
}
|
|
|
|
createPort() {
|
|
this.port = chrome.runtime.connect(null, {name: 'backend-api-forwarder'});
|
|
this.port.onDisconnect.addListener(this.onDisconnect.bind(this));
|
|
this.port.onMessage.addListener(this.onMessage.bind(this));
|
|
}
|
|
|
|
onMessage({type, id, data, senderId}) {
|
|
if (senderId !== this.senderId) { return; }
|
|
switch (type) {
|
|
case 'ack':
|
|
this.onAck(id);
|
|
break;
|
|
case 'result':
|
|
this.onResult(id, data);
|
|
break;
|
|
}
|
|
}
|
|
|
|
onDisconnect() {
|
|
this.disconnected = true;
|
|
|
|
const ids = Object.keys(this.callbacks);
|
|
for (const id of ids) {
|
|
this.onError(id, 'Disconnected');
|
|
}
|
|
}
|
|
|
|
onAck(id) {
|
|
if (!this.callbacks.hasOwnProperty(id)) {
|
|
console.warn(`ID ${id} not found for ack`);
|
|
return;
|
|
}
|
|
|
|
const info = this.callbacks[id];
|
|
if (info.ack) {
|
|
console.warn(`Request ${id} already ack'd`);
|
|
return;
|
|
}
|
|
|
|
info.ack = true;
|
|
clearTimeout(info.timer);
|
|
info.timer = setTimeout(() => this.onError(id, 'Timeout (response)'), this.responseTimeout);
|
|
}
|
|
|
|
onResult(id, data) {
|
|
if (!this.callbacks.hasOwnProperty(id)) {
|
|
console.warn(`ID ${id} not found`);
|
|
return;
|
|
}
|
|
|
|
const info = this.callbacks[id];
|
|
if (!info.ack) {
|
|
console.warn(`Request ${id} not ack'd`);
|
|
return;
|
|
}
|
|
|
|
delete this.callbacks[id];
|
|
clearTimeout(info.timer);
|
|
info.timer = null;
|
|
|
|
if (typeof data.error === 'string') {
|
|
info.reject(data.error);
|
|
} else {
|
|
info.resolve(data.result);
|
|
}
|
|
}
|
|
|
|
onError(id, reason) {
|
|
if (!this.callbacks.hasOwnProperty(id)) { return; }
|
|
const info = this.callbacks[id];
|
|
delete this.callbacks[id];
|
|
info.timer = null;
|
|
info.reject(reason);
|
|
}
|
|
|
|
static generateId(length) {
|
|
let id = '';
|
|
for (let i = 0; i < length; ++i) {
|
|
id += Math.floor(Math.random() * 256).toString(16).padStart(2, '0');
|
|
}
|
|
return id;
|
|
}
|
|
}
|