michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 'use strict';
michael@0: 
michael@0: module.metadata = {
michael@0:   "stability": "stable"
michael@0: };
michael@0: 
michael@0: const { CC, Cc, Ci } = require("chrome");
michael@0: const { when: unload } = require("./system/unload");
michael@0: 
michael@0: const { TYPE_ONE_SHOT, TYPE_REPEATING_SLACK } = Ci.nsITimer;
michael@0: const Timer = CC("@mozilla.org/timer;1", "nsITimer");
michael@0: const timers = Object.create(null);
michael@0: const threadManager = Cc["@mozilla.org/thread-manager;1"].
michael@0:                       getService(Ci.nsIThreadManager);
michael@0: const prefBranch = Cc["@mozilla.org/preferences-service;1"].
michael@0:                     getService(Ci.nsIPrefService).
michael@0:                     QueryInterface(Ci.nsIPrefBranch);
michael@0: 
michael@0: let MIN_DELAY = 4;
michael@0: // Try to get min timeout delay used by browser.
michael@0: try { MIN_DELAY = prefBranch.getIntPref("dom.min_timeout_value"); } finally {}
michael@0: 
michael@0: 
michael@0: // Last timer id.
michael@0: let lastID = 0;
michael@0: 
michael@0: // Sets typer either by timeout or by interval
michael@0: // depending on a given type.
michael@0: function setTimer(type, callback, delay, ...args) {
michael@0:   let id = ++ lastID;
michael@0:   let timer = timers[id] = Timer();
michael@0:   timer.initWithCallback({
michael@0:     notify: function notify() {
michael@0:       try {
michael@0:         if (type === TYPE_ONE_SHOT)
michael@0:           delete timers[id];
michael@0:         callback.apply(null, args);
michael@0:       }
michael@0:       catch(error) {
michael@0:         console.exception(error);
michael@0:       }
michael@0:     }
michael@0:   }, Math.max(delay || MIN_DELAY), type);
michael@0:   return id;
michael@0: }
michael@0: 
michael@0: function unsetTimer(id) {
michael@0:   let timer = timers[id];
michael@0:   delete timers[id];
michael@0:   if (timer) timer.cancel();
michael@0: }
michael@0: 
michael@0: let immediates = new Map();
michael@0: 
michael@0: let dispatcher = _ => {
michael@0:   // Allow scheduling of a new dispatch loop.
michael@0:   dispatcher.scheduled = false;
michael@0:   // Take a snapshot of timer `id`'s that have being present before
michael@0:   // starting a dispatch loop, in order to ignore timers registered
michael@0:   // in side effect to dispatch while also skipping immediates that
michael@0:   // were removed in side effect.
michael@0:   let ids = [id for ([id] of immediates)];
michael@0:   for (let id of ids) {
michael@0:     let immediate = immediates.get(id);
michael@0:     if (immediate) {
michael@0:       immediates.delete(id);
michael@0:       try { immediate(); }
michael@0:       catch (error) { console.exception(error); }
michael@0:     }
michael@0:   }
michael@0: }
michael@0: 
michael@0: function setImmediate(callback, ...params) {
michael@0:   let id = ++ lastID;
michael@0:   // register new immediate timer with curried params.
michael@0:   immediates.set(id, _ => callback.apply(callback, params));
michael@0:   // if dispatch loop is not scheduled schedule one. Own scheduler
michael@0:   if (!dispatcher.scheduled) {
michael@0:     dispatcher.scheduled = true;
michael@0:     threadManager.currentThread.dispatch(dispatcher,
michael@0:                                          Ci.nsIThread.DISPATCH_NORMAL);
michael@0:   }
michael@0:   return id;
michael@0: }
michael@0: 
michael@0: function clearImmediate(id) {
michael@0:   immediates.delete(id);
michael@0: }
michael@0: 
michael@0: // Bind timers so that toString-ing them looks same as on native timers.
michael@0: exports.setImmediate = setImmediate.bind(null);
michael@0: exports.clearImmediate = clearImmediate.bind(null);
michael@0: exports.setTimeout = setTimer.bind(null, TYPE_ONE_SHOT);
michael@0: exports.setInterval = setTimer.bind(null, TYPE_REPEATING_SLACK);
michael@0: exports.clearTimeout = unsetTimer.bind(null);
michael@0: exports.clearInterval = unsetTimer.bind(null);
michael@0: 
michael@0: // all timers are cleared out on unload.
michael@0: unload(function() {
michael@0:   immediates.clear();
michael@0:   Object.keys(timers).forEach(unsetTimer)
michael@0: });