64 lines
1.3 KiB
JavaScript
64 lines
1.3 KiB
JavaScript
// Copyright 2018-2020 Signal Messenger, LLC
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// SPDX-License-Identifier: AGPL-3.0-only
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/* eslint-env browser */
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const EventEmitter = require('events');
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const POLL_INTERVAL_MS = 5 * 1000;
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const IDLE_THRESHOLD_MS = 20;
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class IdleDetector extends EventEmitter {
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constructor() {
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super();
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this.handle = null;
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this.timeoutId = null;
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}
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start() {
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window.log.info('Start idle detector');
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this._scheduleNextCallback();
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}
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stop() {
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if (!this.handle) {
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return;
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}
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window.log.info('Stop idle detector');
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this._clearScheduledCallbacks();
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}
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_clearScheduledCallbacks() {
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if (this.handle) {
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cancelIdleCallback(this.handle);
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this.handle = null;
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}
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if (this.timeoutId) {
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clearTimeout(this.timeoutId);
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this.timeoutId = null;
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}
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}
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_scheduleNextCallback() {
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this._clearScheduledCallbacks();
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this.handle = window.requestIdleCallback(deadline => {
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const { didTimeout } = deadline;
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const timeRemaining = deadline.timeRemaining();
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const isIdle = timeRemaining >= IDLE_THRESHOLD_MS;
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this.timeoutId = setTimeout(
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() => this._scheduleNextCallback(),
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POLL_INTERVAL_MS
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);
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if (isIdle || didTimeout) {
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this.emit('idle', { timestamp: Date.now(), didTimeout, timeRemaining });
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}
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});
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}
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}
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module.exports = {
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IdleDetector,
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};
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