Source code
Revision control
Copy as Markdown
Other Tools
/* -*- 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 STORAGE_SYNC_ENABLED_PREF = "webextensions.storage.sync.enabled";
const NS_ERROR_DOM_QUOTA_EXCEEDED_ERR = 0x80530016;
/** @type {Lazy} */
const lazy = {};
ChromeUtils.defineESModuleGetters(lazy, {
// We might end up falling back to kinto...
extensionStorageSyncKinto:
});
XPCOMUtils.defineLazyPreferenceGetter(
lazy,
"prefPermitsStorageSync",
STORAGE_SYNC_ENABLED_PREF,
true
);
// This xpcom service implements a "bridge" from the JS world to the Rust world.
// It sets up the database and implements a callback-based version of the
// browser.storage API.
ChromeUtils.defineLazyGetter(lazy, "storageSvc", () =>
Cc["@mozilla.org/extensions/storage/sync;1"]
.getService(Ci.nsIInterfaceRequestor)
.getInterface(Ci.mozIExtensionStorageArea)
);
// The interfaces which define the callbacks used by the bridge. There's a
// callback for success, failure, and to record data changes.
function ExtensionStorageApiCallback(resolve, reject, changeCallback) {
this.resolve = resolve;
this.reject = reject;
this.changeCallback = changeCallback;
}
ExtensionStorageApiCallback.prototype = {
QueryInterface: ChromeUtils.generateQI([
"mozIExtensionStorageListener",
"mozIExtensionStorageCallback",
]),
handleSuccess(result) {
this.resolve(result ? JSON.parse(result) : null);
},
handleError(code, message) {
/** @type {Error & { code?: number }} */
let e = new Error(message);
e.code = code;
Cu.reportError(e);
this.reject(e);
},
onChanged(extId, json) {
if (this.changeCallback && json) {
try {
this.changeCallback(extId, JSON.parse(json));
} catch (ex) {
Cu.reportError(ex);
}
}
},
};
// The backing implementation of the browser.storage.sync web extension API.
export class ExtensionStorageSync {
constructor() {
this.listeners = new Map();
// We are optimistic :) If we ever see the special nsresult which indicates
// migration failure, it will become false. In practice, this will only ever
// happen on the first operation.
this.migrationOk = true;
}
// The main entry-point to our bridge. It performs some important roles:
// * Ensures the API is allowed to be used.
// * Works out what "extension id" to use.
// * Turns the callback API into a promise API.
async _promisify(fnName, extension, context, ...args) {
let extId = extension.id;
if (lazy.prefPermitsStorageSync !== true) {
throw new lazy.ExtensionUtils.ExtensionError(
`Please set ${STORAGE_SYNC_ENABLED_PREF} to true in about:config`
);
}
if (this.migrationOk) {
// We can call ours.
try {
return await new Promise((resolve, reject) => {
let callback = new ExtensionStorageApiCallback(
resolve,
reject,
(extId, changes) => this.notifyListeners(extId, changes)
);
let sargs = args.map(val => JSON.stringify(val));
lazy.storageSvc[fnName](extId, ...sargs, callback);
});
} catch (ex) {
if (ex.code != Cr.NS_ERROR_CANNOT_CONVERT_DATA) {
// Some non-migration related error we want to sanitize and propagate.
// The only "public" exception here is for quota failure - all others
// are sanitized.
let sanitized =
ex.code == NS_ERROR_DOM_QUOTA_EXCEEDED_ERR
? // The same message as the local IDB implementation
`QuotaExceededError: storage.sync API call exceeded its quota limitations.`
: // The standard, generic extension error.
"An unexpected error occurred";
throw new lazy.ExtensionUtils.ExtensionError(sanitized);
}
// This means "migrate failed" so we must fall back to kinto.
Cu.reportError(
"migration of extension-storage failed - will fall back to kinto"
);
this.migrationOk = false;
}
}
// We've detected failure to migrate, so we want to use kinto.
return lazy.extensionStorageSyncKinto[fnName](extension, ...args, context);
}
set(extension, items, context) {
return this._promisify("set", extension, context, items);
}
remove(extension, keys, context) {
return this._promisify("remove", extension, context, keys);
}
clear(extension, context) {
return this._promisify("clear", extension, context);
}
clearOnUninstall(extensionId) {
if (!this.migrationOk) {
// If the rust-based backend isn't being used,
// no need to clear it.
return;
}
// Resolve the returned promise once the request has been either resolved
// or rejected (and report the error on the browser console in case of
// unexpected clear failures on addon uninstall).
return new Promise(resolve => {
const callback = new ExtensionStorageApiCallback(
resolve,
err => {
Cu.reportError(err);
resolve();
},
// empty changeCallback (no need to notify the extension
// while clearing the extension on uninstall).
() => {}
);
lazy.storageSvc.clear(extensionId, callback);
});
}
get(extension, spec, context) {
return this._promisify("get", extension, context, spec);
}
getBytesInUse(extension, keys, context) {
return this._promisify("getBytesInUse", extension, context, keys);
}
addOnChangedListener(extension, listener) {
let listeners = this.listeners.get(extension.id) || new Set();
listeners.add(listener);
this.listeners.set(extension.id, listeners);
}
removeOnChangedListener(extension, listener) {
let listeners = this.listeners.get(extension.id);
listeners.delete(listener);
if (listeners.size == 0) {
this.listeners.delete(extension.id);
}
}
notifyListeners(extId, changes) {
let listeners = this.listeners.get(extId) || new Set();
if (listeners) {
for (let listener of listeners) {
lazy.ExtensionCommon.runSafeSyncWithoutClone(listener, changes);
}
}
}
}
export var extensionStorageSync = new ExtensionStorageSync();