Source code
Revision control
Copy as Markdown
Other Tools
/* 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
import { AppConstants } from "resource://gre/modules/AppConstants.sys.mjs";
const lazy = {};
ChromeUtils.defineESModuleGetters(lazy, {
TaskScheduler: "resource://gre/modules/TaskScheduler.sys.mjs",
});
ChromeUtils.defineLazyGetter(lazy, "log", () =>
console.createInstance({
maxLogLevel: "Error",
maxLogLevelPref: "app.defaultagent.loglevel",
prefix: "DefaultAgentScheduler",
})
);
const TASK_MODULE = "defaultagent";
// The WinRT task registration name (and identity). The MSIX background task COM
// server splits on ":" - firefox --backgroundtask TASK_MODULE do-task`.
const TASK_ID = `${TASK_MODULE}:do-task`;
const INTERVAL_SECONDS = 24 * 60 * 60;
const ENABLED_PREF = "default-browser-agent.enabled";
// Records the task parameters (name, interval, and entry point) the task was
// last registered with.
const REGISTERED_PARAMS_PREF = "default-browser-agent.msix.registered-params";
// Recorded as JSON because the task name itself contains ":"
function taskParams() {
return JSON.stringify({
id: TASK_ID,
intervalSeconds: INTERVAL_SECONDS,
entryPoint: AppConstants.MOZ_BACKGROUNDTASK_ACTIVATABLE_CLASS_ID,
});
}
/**
* The task name recorded by a previous registration, if it differs from the
* name in use now.
*
* @returns {?string} the stale task name, or null if there isn't one.
*/
function staleTaskId() {
let recorded = Services.prefs.getStringPref(REGISTERED_PARAMS_PREF, "");
if (!recorded) {
return null;
}
let id;
try {
id = JSON.parse(recorded).id;
} catch (e) {
// Written by a version that recorded a different format; nothing to remove.
return null;
}
return id && id != TASK_ID ? id : null;
}
async function deleteTaskIfRegistered(id) {
if (!id) {
return;
}
try {
await lazy.TaskScheduler.deleteTask(id);
lazy.log.info(`Removed previously registered task "${id}".`);
} catch (e) {
// Throws NS_ERROR_FILE_NOT_FOUND when there is no such task.
lazy.log.error(`Could not remove previously registered task: ${e}`);
}
}
/**
* Schedules the Windows default browser agent on MSIX (packaged) installs.
*
* This is the packaged-install counterpart to the classic registration done by
* the NSIS installer via default-browser-agent.exe.
*/
export const DefaultAgentScheduler = {
TASK_ID,
INTERVAL_SECONDS,
_initialized: false,
// The MSIX path only applies to packaged Windows builds that actually ship
// the default agent component.
get appliesToThisInstall() {
return (
AppConstants.platform == "win" &&
"@mozilla.org/default-agent;1" in Cc &&
Services.sysinfo.getProperty("hasWinPackageId")
);
},
get disabled() {
let agent = Cc["@mozilla.org/default-agent;1"].getService(
Ci.nsIDefaultAgent
);
return agent.agentDisabled();
},
observe(subject, topic, data) {
if (topic == "nsPref:changed" && data == ENABLED_PREF) {
this.maybeScheduleDefaultAgentTask().catch(e => lazy.log.error(e));
}
},
/**
* Register or unregister the background task to match the current enabled
* state. Safe to call on every startup: it only registers when there is no
* task yet or when an update changed the task parameters, so ordinary
* restarts leave an existing registration untouched.
*
* @returns {Promise<boolean>} true if a task is scheduled afterwards.
*/
async maybeScheduleDefaultAgentTask() {
if (!this.appliesToThisInstall) {
return false;
}
if (!this._initialized) {
Services.prefs.addObserver(ENABLED_PREF, this);
this._initialized = true;
}
let exists = false;
try {
exists = await lazy.TaskScheduler.taskExists(TASK_ID);
} catch (e) {
// State is unknown; fall through and (re-)register below.
lazy.log.error(`taskExists failed: ${e}`);
}
let stale = staleTaskId();
if (this.disabled) {
if (exists) {
await lazy.TaskScheduler.deleteTask(TASK_ID);
}
await deleteTaskIfRegistered(stale);
if (exists || stale) {
Services.prefs.clearUserPref(REGISTERED_PARAMS_PREF);
lazy.log.info("Agent disabled; deleted default agent task.");
}
return false;
}
// Only (re-)register when necessary, on first run, or after an update that
// changed the task parameters. Note: in the future, if we notice this changing
// quite frequently, we should switch to using the registry to preserve the daily cadence
// of the defaultagent.
const params = taskParams();
if (
exists &&
Services.prefs.getStringPref(REGISTERED_PARAMS_PREF, "") == params
) {
return true;
}
// A previous version may have registered under a different name. Windows
// keeps that registration until it is explicitly unregistered, so it would
// otherwise keep launching the task alongside the new registration.
await deleteTaskIfRegistered(stale);
// The WinRT BackgroundTask API does not use the command arg.
await lazy.TaskScheduler.registerTask(TASK_ID, null, INTERVAL_SECONDS);
Services.prefs.setStringPref(REGISTERED_PARAMS_PREF, params);
lazy.log.info("Agent enabled; registered default agent task.");
return true;
},
};