зеркало из https://github.com/mozilla/gecko-dev.git
77 строки
2.1 KiB
JavaScript
77 строки
2.1 KiB
JavaScript
/* -*- mode: js; indent-tabs-mode: nil; js-indent-level: 2 -*- */
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/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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"use strict";
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var EXPORTED_SYMBOLS = ["TabUnloader"];
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const {Services} = ChromeUtils.import("resource://gre/modules/Services.jsm");
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/**
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* This module is responsible for detecting low-memory scenarios and unloading
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* tabs in response to them.
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*/
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var TabUnloader = {
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/**
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* Initialize low-memory detection and tab auto-unloading.
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*/
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init() {
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if (Services.prefs.getBoolPref("browser.tabs.unloadOnLowMemory", true)) {
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Services.obs.addObserver(this, "memory-pressure", /* ownsWeak */ true);
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}
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},
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observe(subject, topic, data) {
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if (topic == "memory-pressure" && data != "heap-minimize") {
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unloadLeastRecentlyUsedTab();
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}
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},
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QueryInterface: ChromeUtils.generateQI([
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Ci.nsIObserver,
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Ci.nsISupportsWeakReference,
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]),
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};
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function unloadLeastRecentlyUsedTab() {
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let bgTabBrowsers = getSortedBackgroundTabBrowsers();
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for (let tb of bgTabBrowsers) {
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if (tb.browser.discardBrowser(tb.tab)) {
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return;
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}
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}
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}
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/* Sort tabs in the order we use for unloading, first non-pinned, non-audible
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* tabs in LRU order, then non-audible tabs in LRU order, then non-pinned
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* audible tabs in LRU order and finally pinned, audible tabs in LRU order. */
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function sortTabs(a, b) {
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if (a.tab.soundPlaying != b.tab.soundPlaying) {
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return a.tab.soundPlaying - b.tab.soundPlaying;
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}
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if (a.tab.pinned != b.tab.pinned) {
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return a.tab.pinned - b.tab.pinned;
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}
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return a.tab.lastAccessed - b.tab.lastAccessed;
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}
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function getSortedBackgroundTabBrowsers() {
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let bgTabBrowsers = [];
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for (let win of Services.wm.getEnumerator("navigator:browser")) {
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for (let tab of win.gBrowser.tabs) {
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if (!tab.selected && tab.linkedBrowser.isConnected) {
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bgTabBrowsers.push({ tab, browser: win.gBrowser });
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}
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}
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}
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return bgTabBrowsers.sort(sortTabs);
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}
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