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/* -*- Mode: indent-tabs-mode: nil; js-indent-level: 2 -*- */
/* vim: set sts=2 sw=2 et tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
const lazy = {};
ChromeUtils.defineESModuleGetters(lazy, {
});
// xpcshell doesn't handle idle callbacks well.
ChromeUtils.defineLazyGetter(lazy, "idleTimeout", () =>
Services.appinfo.name === "XPCShell" ? 500 : undefined
);
// It would be nicer to go through `Services.appinfo`, but some tests need to be
// able to replace that field with a custom implementation before it is first
// called.
// eslint-disable-next-line mozilla/use-services
const appinfo = Cc["@mozilla.org/xre/app-info;1"].getService(Ci.nsIXULRuntime);
let nextId = 0;
const uniqueProcessID = appinfo.uniqueProcessID;
// Store the process ID in a 16 bit field left shifted to end of a
// double's mantissa.
// Note: We can't use bitwise ops here, since they truncate to a 32 bit
// integer and we need all 53 mantissa bits.
const processIDMask = (uniqueProcessID & 0xffff) * 2 ** 37;
function getUniqueId() {
// Note: We can't use bitwise ops here, since they truncate to a 32 bit
// integer and we need all 53 mantissa bits.
return processIDMask + nextId++;
}
function promiseTimeout(delay) {
return new Promise(resolve => lazy.setTimeout(resolve, delay));
}
/**
* An Error subclass for which complete error messages are always passed
* to extensions, rather than being interpreted as an unknown error.
*/
export class ExtensionError extends DOMException {
constructor(message) {
super(message, "ExtensionError");
}
// Custom JS classes can't survive IPC, so need to check error name.
static [Symbol.hasInstance](e) {
return DOMException.isInstance(e) && e.name === "ExtensionError";
}
}
function filterStack(error) {
return String(error.stack).replace(
/(^.*(Task\.jsm|Promise-backend\.js).*\n)+/gm,
"<Promise Chain>\n"
);
}
/**
* An Error subclass used to recognize the errors that should
* to be forwarded to the worker thread and being accessible
* to the extension worker script (vs. the errors that should be
* only logged internally and raised to the worker script as
* the generic unexpected error).
*/
export class WorkerExtensionError extends DOMException {
constructor(message) {
super(message, "Error");
}
}
/**
* Similar to a WeakMap, but creates a new key with the given
* constructor if one is not present.
*/
class DefaultWeakMap extends WeakMap {
constructor(defaultConstructor = undefined, init = undefined) {
super(init);
if (defaultConstructor) {
this.defaultConstructor = defaultConstructor;
}
}
get(key) {
let value = super.get(key);
if (value === undefined && !this.has(key)) {
value = this.defaultConstructor(key);
this.set(key, value);
}
return value;
}
}
class DefaultMap extends Map {
constructor(defaultConstructor = undefined, init = undefined) {
super(init);
if (defaultConstructor) {
this.defaultConstructor = defaultConstructor;
}
}
get(key) {
let value = super.get(key);
if (value === undefined && !this.has(key)) {
value = this.defaultConstructor(key);
this.set(key, value);
}
return value;
}
}
function getInnerWindowID(window) {
return window.windowGlobalChild?.innerWindowId;
}
/**
* A set with a limited number of slots, which flushes older entries as
* newer ones are added.
*
* @param {number} limit
* The maximum size to trim the set to after it grows too large.
* @param {number} [slop = limit * .25]
* The number of extra entries to allow in the set after it
* reaches the size limit, before it is truncated to the limit.
* @param {Iterable} [iterable]
* An iterable of initial entries to add to the set.
*/
class LimitedSet extends Set {
constructor(limit, slop = Math.round(limit * 0.25), iterable = undefined) {
super(iterable);
this.limit = limit;
this.slop = slop;
}
truncate(limit) {
for (let item of this) {
// Live set iterators can ge relatively expensive, since they need
// to be updated after every modification to the set. Since
// breaking out of the loop early will keep the iterator alive
// until the next full GC, we're currently better off finishing
// the entire loop even after we're done truncating.
if (this.size > limit) {
this.delete(item);
}
}
}
add(item) {
if (this.size >= this.limit + this.slop && !this.has(item)) {
this.truncate(this.limit - 1);
}
return super.add(item);
}
}
/**
* Returns a Promise which resolves when the given document's DOM has
* fully loaded.
*
* @param {Document} doc The document to await the load of.
* @returns {Promise<Document>}
*/
function promiseDocumentReady(doc) {
if (doc.readyState == "interactive" || doc.readyState == "complete") {
return Promise.resolve(doc);
}
return new Promise(resolve => {
doc.addEventListener(
"DOMContentLoaded",
function onReady(event) {
if (event.target === event.currentTarget) {
doc.removeEventListener("DOMContentLoaded", onReady, true);
resolve(doc);
}
},
true
);
});
}
/**
* Returns a Promise which resolves when the given window's document's DOM has
* fully loaded, the <head> stylesheets have fully loaded, and we have hit an
* idle time.
*
* @param {Window} window The window whose document we will await
the readiness of.
* @returns {Promise<IdleDeadline>}
*/
function promiseDocumentIdle(window) {
return window.document.documentReadyForIdle.then(() => {
return new Promise(resolve =>
window.requestIdleCallback(resolve, { timeout: lazy.idleTimeout })
);
});
}
/**
* Returns a Promise which resolves when the given document is fully
* loaded.
*
* @param {Document} doc The document to await the load of.
* @returns {Promise<Document>}
*/
function promiseDocumentLoaded(doc) {
if (doc.readyState == "complete") {
return Promise.resolve(doc);
}
return new Promise(resolve => {
doc.defaultView.addEventListener("load", () => resolve(doc), {
once: true,
});
});
}
/**
* Returns a Promise which resolves when the given event is dispatched to the
* given element.
*
* @param {Element} element
* The element on which to listen.
* @param {string} eventName
* The event to listen for.
* @param {boolean} [useCapture = true]
* If true, listen for the even in the capturing rather than
* bubbling phase.
* @param {function(Event): boolean} [test]
* An optional test function which, when called with the
* observer's subject and data, should return true if this is the
* expected event, false otherwise.
* @returns {Promise<Event>}
*/
function promiseEvent(
element,
eventName,
useCapture = true,
test = () => true
) {
return new Promise(resolve => {
function listener(event) {
if (test(event)) {
element.removeEventListener(eventName, listener, useCapture);
resolve(event);
}
}
element.addEventListener(eventName, listener, useCapture);
});
}
/**
* Returns a Promise which resolves the given observer topic has been
* observed.
*
* @param {string} topic
* The topic to observe.
* @param {function(any, string): boolean} [test]
* An optional test function which, when called with the
* observer's subject and data, should return true if this is the
* expected notification, false otherwise.
* @returns {Promise<object>}
*/
function promiseObserved(topic, test = () => true) {
return new Promise(resolve => {
let observer = (subject, topic, data) => {
if (test(subject, data)) {
Services.obs.removeObserver(observer, topic);
resolve({ subject, data });
}
};
Services.obs.addObserver(observer, topic);
});
}
function getMessageManager(target) {
if (target.frameLoader) {
return target.frameLoader.messageManager;
}
return target;
}
function flushJarCache(jarPath) {
Services.obs.notifyObservers(null, "flush-cache-entry", jarPath);
}
function parseMatchPatterns(patterns, options) {
try {
return new MatchPatternSet(patterns, options);
} catch (e) {
let pattern;
for (pattern of patterns) {
try {
new MatchPattern(pattern, options);
} catch (e) {
throw new ExtensionError(`Invalid url pattern: ${pattern}`);
}
}
// Unexpectedly MatchPatternSet threw, but MatchPattern did not.
throw e;
}
}
/**
* Fetch icon content and convert it to a data: URI.
*
* @param {string} iconUrl Icon url to fetch.
* @returns {Promise<string>}
*/
async function makeDataURI(iconUrl) {
let response;
try {
response = await fetch(iconUrl);
} catch (e) {
// Failed to fetch, ignore engine's favicon.
Cu.reportError(e);
return;
}
let buffer = await response.arrayBuffer();
let contentType = response.headers.get("content-type");
let bytes = new Uint8Array(buffer);
let str = String.fromCharCode.apply(null, bytes);
return `data:${contentType};base64,${btoa(str)}`;
}
export var ExtensionUtils = {
flushJarCache,
getInnerWindowID,
getMessageManager,
getUniqueId,
filterStack,
makeDataURI,
parseMatchPatterns,
promiseDocumentIdle,
promiseDocumentLoaded,
promiseDocumentReady,
promiseEvent,
promiseObserved,
promiseTimeout,
DefaultMap,
DefaultWeakMap,
ExtensionError,
LimitedSet,
};