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author | Matt A. Tobin <mattatobin@localhost.localdomain> | 2018-02-02 04:16:08 -0500 |
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committer | Matt A. Tobin <mattatobin@localhost.localdomain> | 2018-02-02 04:16:08 -0500 |
commit | 5f8de423f190bbb79a62f804151bc24824fa32d8 (patch) | |
tree | 10027f336435511475e392454359edea8e25895d /devtools/shared/worker/worker.js | |
parent | 49ee0794b5d912db1f95dce6eb52d781dc210db5 (diff) | |
download | uxp-5f8de423f190bbb79a62f804151bc24824fa32d8.tar.gz |
Add m-esr52 at 52.6.0
Diffstat (limited to 'devtools/shared/worker/worker.js')
-rw-r--r-- | devtools/shared/worker/worker.js | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/devtools/shared/worker/worker.js b/devtools/shared/worker/worker.js new file mode 100644 index 0000000000..9ed9afa279 --- /dev/null +++ b/devtools/shared/worker/worker.js @@ -0,0 +1,171 @@ +/* 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 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +"use strict"; + +/* global ChromeWorker */ + +(function (factory) { + if (this.module && module.id.indexOf("worker") >= 0) { + // require + const { Cc, Ci, Cu, ChromeWorker } = require("chrome"); + const dumpn = require("devtools/shared/DevToolsUtils").dumpn; + factory.call(this, require, exports, module, { Cc, Ci, Cu }, ChromeWorker, dumpn); + } else { + // Cu.import + const { classes: Cc, interfaces: Ci, utils: Cu } = Components; + const { require } = Cu.import("resource://devtools/shared/Loader.jsm", {}); + this.isWorker = false; + this.Promise = Cu.import("resource://gre/modules/Promise.jsm", {}).Promise; + this.console = Cu.import("resource://gre/modules/Console.jsm", {}).console; + factory.call( + this, require, this, { exports: this }, + { Cc, Ci, Cu }, ChromeWorker, null + ); + this.EXPORTED_SYMBOLS = ["DevToolsWorker"]; + } +}).call(this, function (require, exports, module, { Ci, Cc }, ChromeWorker, dumpn) { + let MESSAGE_COUNTER = 0; + + /** + * Creates a wrapper around a ChromeWorker, providing easy + * communication to offload demanding tasks. The corresponding URL + * must implement the interface provided by `devtools/shared/worker/helper`. + * + * @see `./devtools/client/shared/widgets/GraphsWorker.js` + * + * @param {string} url + * The URL of the worker. + * @param Object opts + * An option with the following optional fields: + * - name: a name that will be printed with logs + * - verbose: log incoming and outgoing messages + */ + function DevToolsWorker(url, opts) { + opts = opts || {}; + this._worker = new ChromeWorker(url); + this._verbose = opts.verbose; + this._name = opts.name; + + this._worker.addEventListener("error", this.onError, false); + } + exports.DevToolsWorker = DevToolsWorker; + + /** + * Performs the given task in a chrome worker, passing in data. + * Returns a promise that resolves when the task is completed, resulting in + * the return value of the task. + * + * @param {string} task + * The name of the task to execute in the worker. + * @param {any} data + * Data to be passed into the task implemented by the worker. + * @return {Promise} + */ + DevToolsWorker.prototype.performTask = function (task, data) { + if (this._destroyed) { + return Promise.reject("Cannot call performTask on a destroyed DevToolsWorker"); + } + let worker = this._worker; + let id = ++MESSAGE_COUNTER; + let payload = { task, id, data }; + + if (this._verbose && dumpn) { + dumpn("Sending message to worker" + + (this._name ? (" (" + this._name + ")") : "") + + ": " + + JSON.stringify(payload, null, 2)); + } + worker.postMessage(payload); + + return new Promise((resolve, reject) => { + let listener = ({ data: result }) => { + if (this._verbose && dumpn) { + dumpn("Received message from worker" + + (this._name ? (" (" + this._name + ")") : "") + + ": " + + JSON.stringify(result, null, 2)); + } + + if (result.id !== id) { + return; + } + worker.removeEventListener("message", listener); + if (result.error) { + reject(result.error); + } else { + resolve(result.response); + } + }; + + worker.addEventListener("message", listener); + }); + }; + + /** + * Terminates the underlying worker. Use when no longer needing the worker. + */ + DevToolsWorker.prototype.destroy = function () { + this._worker.terminate(); + this._worker = null; + this._destroyed = true; + }; + + DevToolsWorker.prototype.onError = function ({ message, filename, lineno }) { + dump(new Error(message + " @ " + filename + ":" + lineno) + "\n"); + }; + + /** + * Takes a function and returns a Worker-wrapped version of the same function. + * Returns a promise upon resolution. + * @see `./devtools/shared/shared/tests/browser/browser_devtools-worker-03.js + * + * ⚠ This should only be used for tests or A/B testing performance ⚠ + * + * The original function must: + * + * Be a pure function, that is, not use any variables not declared within the + * function, or its arguments. + * + * Return a value or a promise. + * + * Note any state change in the worker will not affect the callee's context. + * + * @param {function} fn + * @return {function} + */ + function workerify(fn) { + console.warn("`workerify` should only be used in tests or measuring performance. " + + "This creates an object URL on the browser window, and should not be " + + "used in production."); + // Fetch via window/utils here as we don't want to include + // this module normally. + let { getMostRecentBrowserWindow } = require("sdk/window/utils"); + let { URL, Blob } = getMostRecentBrowserWindow(); + let stringifiedFn = createWorkerString(fn); + let blob = new Blob([stringifiedFn]); + let url = URL.createObjectURL(blob); + let worker = new DevToolsWorker(url); + + let wrapperFn = data => worker.performTask("workerifiedTask", data); + + wrapperFn.destroy = function () { + URL.revokeObjectURL(url); + worker.destroy(); + }; + + return wrapperFn; + } + exports.workerify = workerify; + + /** + * Takes a function, and stringifies it, attaching the worker-helper.js + * boilerplate hooks. + */ + function createWorkerString(fn) { + return `importScripts("resource://gre/modules/workers/require.js"); + const { createTask } = require("resource://devtools/shared/worker/helper.js"); + createTask(self, "workerifiedTask", ${fn.toString()});`; + } +}); |