The Tor Browser: toolkit/devtools/server/actors/storage.js@129ffea94266 (annotated)

toolkit/devtools/server/actors/storage.js@129ffea94266 (annotated)

toolkit/devtools/server/actors/storage.js

Sat, 03 Jan 2015 20:18:00 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Sat, 03 Jan 2015 20:18:00 +0100
branch: TOR_BUG_3246
changeset 7: 129ffea94266
permissions: -rw-r--r--

Conditionally enable double key logic according to:
private browsing mode or privacy.thirdparty.isolate preference and
implement in GetCookieStringCommon and FindCookie where it counts...
With some reservations of how to convince FindCookie users to test
condition and pass a nullptr when disabling double key logic.

 /* 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";
 const {Cu, Cc, Ci} = require("chrome");
 const events = require("sdk/event/core");
 const protocol = require("devtools/server/protocol");
 const {async} = require("devtools/async-utils");
 const {Arg, Option, method, RetVal, types} = protocol;
 const {LongStringActor, ShortLongString} = require("devtools/server/actors/string");
 Cu.import("resource://gre/modules/Promise.jsm");
 Cu.import("resource://gre/modules/Services.jsm");
 Cu.import("resource://gre/modules/XPCOMUtils.jsm");
 Cu.import("resource://gre/modules/devtools/LayoutHelpers.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "Sqlite",
   "resource://gre/modules/Sqlite.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "OS",
   "resource://gre/modules/osfile.jsm");
 exports.register = function(handle) {
   handle.addTabActor(StorageActor, "storageActor");
 };
 exports.unregister = function(handle) {
   handle.removeTabActor(StorageActor);
 };
 // Global required for window less Indexed DB instantiation.
 let global = this;
 // Maximum number of cookies/local storage key-value-pairs that can be sent
 // over the wire to the client in one request.
 const MAX_STORE_OBJECT_COUNT = 30;
 // Interval for the batch job that sends the accumilated update packets to the
 // client.
 const UPDATE_INTERVAL = 500; // ms
 // A RegExp for characters that cannot appear in a file/directory name. This is
 // used to sanitize the host name for indexed db to lookup whether the file is
 // present in <profileDir>/storage/persistent/ location
 let illegalFileNameCharacters = [
   "[",
   "\\x00-\\x25",     // Control characters \001 to \037
   "/:*?\\\"<>|\\\\", // Special characters
   "]"
 ].join("");
 let ILLEGAL_CHAR_REGEX = new RegExp(illegalFileNameCharacters, "g");
 // Holder for all the registered storage actors.
 let storageTypePool = new Map();
 /**
  * Gets an accumulated list of all storage actors registered to be used to
  * create a RetVal to define the return type of StorageActor.listStores method.
  */
 function getRegisteredTypes() {
   let registeredTypes = {};
   for (let store of storageTypePool.keys()) {
     registeredTypes[store] = store;
   }
   return registeredTypes;
 }
 /**
  * An async method equivalent to setTimeout but using Promises
  *
  * @param {number} time
  *        The wait Ttme in milliseconds.
  */
 function sleep(time) {
   let wait = Promise.defer();
   let updateTimer = Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer);
   updateTimer.initWithCallback({
     notify: function() {
       updateTimer.cancel();
       updateTimer = null;
       wait.resolve(null);
     }
   } , time, Ci.nsITimer.TYPE_ONE_SHOT);
   return wait.promise;
 }
 // Cookies store object
 types.addDictType("cookieobject", {
   name: "string",
   value: "longstring",
   path: "nullable:string",
   host: "string",
   isDomain: "boolean",
   isSecure: "boolean",
   isHttpOnly: "boolean",
   creationTime: "number",
   lastAccessed: "number",
   expires: "number"
 });
 // Array of cookie store objects
 types.addDictType("cookiestoreobject", {
   total: "number",
   offset: "number",
   data: "array:nullable:cookieobject"
 });
 // Local Storage / Session Storage store object
 types.addDictType("storageobject", {
   name: "string",
   value: "longstring"
 });
 // Array of Local Storage / Session Storage store objects
 types.addDictType("storagestoreobject", {
   total: "number",
   offset: "number",
   data: "array:nullable:storageobject"
 });
 // Indexed DB store object
 // This is a union on idb object, db metadata object and object store metadata
 // object
 types.addDictType("idbobject", {
   name: "nullable:string",
   db: "nullable:string",
   objectStore: "nullable:string",
   origin: "nullable:string",
   version: "nullable:number",
   objectStores: "nullable:number",
   keyPath: "nullable:string",
   autoIncrement: "nullable:boolean",
   indexes: "nullable:string",
   value: "nullable:longstring"
 });
 // Array of Indexed DB store objects
 types.addDictType("idbstoreobject", {
   total: "number",
   offset: "number",
   data: "array:nullable:idbobject"
 });
 // Update notification object
 types.addDictType("storeUpdateObject", {
   changed: "nullable:json",
   deleted: "nullable:json",
   added: "nullable:json"
 });
 // Helper methods to create a storage actor.
 let StorageActors = {};
 /**
  * Creates a default object with the common methods required by all storage
  * actors.
  *
  * This default object is missing a couple of required methods that should be
  * implemented seperately for each actor. They are namely:
  *   - observe : Method which gets triggered on the notificaiton of the watched
  *               topic.
  *   - getNamesForHost : Given a host, get list of all known store names.
  *   - getValuesForHost : Given a host (and optianally a name) get all known
  *                        store objects.
  *   - toStoreObject : Given a store object, convert it to the required format
  *                     so that it can be transferred over wire.
  *   - populateStoresForHost : Given a host, populate the map of all store
  *                             objects for it
  *
  * @param {string} typeName
  *        The typeName of the actor.
  * @param {string} observationTopic
  *        The topic which this actor listens to via Notification Observers.
  * @param {string} storeObjectType
  *        The RetVal type of the store object of this actor.
  */
 StorageActors.defaults = function(typeName, observationTopic, storeObjectType) {
   return {
     typeName: typeName,
     get conn() {
       return this.storageActor.conn;
     },
     /**
      * Returns a list of currently knwon hosts for the target window. This list
      * contains unique hosts from the window + all inner windows.
      */
     get hosts() {
       let hosts = new Set();
       for (let {location} of this.storageActor.windows) {
         hosts.add(this.getHostName(location));
       }
       return hosts;
     },
     /**
      * Returns all the windows present on the page. Includes main window + inner
      * iframe windows.
      */
     get windows() {
       return this.storageActor.windows;
     },
     /**
      * Converts the window.location object into host.
      */
     getHostName: function(location) {
       return location.hostname || location.href;
     },
     initialize: function(storageActor) {
       protocol.Actor.prototype.initialize.call(this, null);
       this.storageActor = storageActor;
       this.populateStoresForHosts();
       if (observationTopic) {
         Services.obs.addObserver(this, observationTopic, false);
       }
       this.onWindowReady = this.onWindowReady.bind(this);
       this.onWindowDestroyed = this.onWindowDestroyed.bind(this);
       events.on(this.storageActor, "window-ready", this.onWindowReady);
       events.on(this.storageActor, "window-destroyed", this.onWindowDestroyed);
     },
     destroy: function() {
       this.hostVsStores = null;
       if (observationTopic) {
         Services.obs.removeObserver(this, observationTopic, false);
       }
       events.off(this.storageActor, "window-ready", this.onWindowReady);
       events.off(this.storageActor, "window-destroyed", this.onWindowDestroyed);
     },
     getNamesForHost: function(host) {
       return [...this.hostVsStores.get(host).keys()];
     },
     getValuesForHost: function(host, name) {
       if (name) {
         return [this.hostVsStores.get(host).get(name)];
       }
       return [...this.hostVsStores.get(host).values()];
     },
     getObjectsSize: function(host, names) {
       return names.length;
     },
     /**
      * When a new window is added to the page. This generally means that a new
      * iframe is created, or the current window is completely reloaded.
      *
      * @param {window} window
      *        The window which was added.
      */
     onWindowReady: async(function*(window) {
       let host = this.getHostName(window.location);
       if (!this.hostVsStores.has(host)) {
         yield this.populateStoresForHost(host, window);
         let data = {};
         data[host] = this.getNamesForHost(host);
         this.storageActor.update("added", typeName, data);
       }
     }),
     /**
      * When a window is removed from the page. This generally means that an
      * iframe was removed, or the current window reload is triggered.
      *
      * @param {window} window
      *        The window which was removed.
      */
     onWindowDestroyed: function(window) {
       let host = this.getHostName(window.location);
       if (!this.hosts.has(host)) {
         this.hostVsStores.delete(host);
         let data = {};
         data[host] = [];
         this.storageActor.update("deleted", typeName, data);
       }
     },
     form: function(form, detail) {
       if (detail === "actorid") {
         return this.actorID;
       }
       let hosts = {};
       for (let host of this.hosts) {
         hosts[host] = [];
       }
       return {
         actor: this.actorID,
         hosts: hosts
       };
     },
     /**
      * Populates a map of known hosts vs a map of stores vs value.
      */
     populateStoresForHosts: function() {
       this.hostVsStores = new Map();
       for (let host of this.hosts) {
         this.populateStoresForHost(host);
       }
     },
     /**
      * Returns a list of requested store objects. Maximum values returned are
      * MAX_STORE_OBJECT_COUNT. This method returns paginated values whose
      * starting index and total size can be controlled via the options object
      *
      * @param {string} host
      *        The host name for which the store values are required.
      * @param {array:string} names
      *        Array containing the names of required store objects. Empty if all
      *        items are required.
      * @param {object} options
      *        Additional options for the request containing following properties:
      *         - offset {number} : The begin index of the returned array amongst
      *                  the total values
      *         - size {number} : The number of values required.
      *         - sortOn {string} : The values should be sorted on this property.
      *         - index {string} : In case of indexed db, the IDBIndex to be used
      *                 for fetching the values.
      *
      * @return {object} An object containing following properties:
      *          - offset - The actual offset of the returned array. This might
      *                     be different from the requested offset if that was
      *                     invalid
      *          - total - The total number of entries possible.
      *          - data - The requested values.
      */
     getStoreObjects: method(async(function*(host, names, options = {}) {
       let offset = options.offset || 0;
       let size = options.size || MAX_STORE_OBJECT_COUNT;
       if (size > MAX_STORE_OBJECT_COUNT) {
         size = MAX_STORE_OBJECT_COUNT;
       }
       let sortOn = options.sortOn || "name";
       let toReturn = {
         offset: offset,
         total: 0,
         data: []
       };
       if (names) {
         for (let name of names) {
           toReturn.data.push(
             // yield because getValuesForHost is async for Indexed DB
             ...(yield this.getValuesForHost(host, name, options))
           );
         }
         toReturn.total = this.getObjectsSize(host, names, options);
         if (offset > toReturn.total) {
           // In this case, toReturn.data is an empty array.
           toReturn.offset = toReturn.total;
           toReturn.data = [];
         }
         else {
           toReturn.data = toReturn.data.sort((a,b) => {
             return a[sortOn] - b[sortOn];
           }).slice(offset, offset + size).map(a => this.toStoreObject(a));
         }
       }
       else {
         let total = yield this.getValuesForHost(host);
         toReturn.total = total.length;
         if (offset > toReturn.total) {
           // In this case, toReturn.data is an empty array.
           toReturn.offset = offset = toReturn.total;
           toReturn.data = [];
         }
         else {
           toReturn.data = total.sort((a,b) => {
             return a[sortOn] - b[sortOn];
           }).slice(offset, offset + size)
             .map(object => this.toStoreObject(object));
         }
       }
       return toReturn;
     }), {
       request: {
         host: Arg(0),
         names: Arg(1, "nullable:array:string"),
         options: Arg(2, "nullable:json")
       },
       response: RetVal(storeObjectType)
     })
   }
 };
 /**
  * Creates an actor and its corresponding front and registers it to the Storage
  * Actor.
  *
  * @See StorageActors.defaults()
  *
  * @param {object} options
  *        Options required by StorageActors.defaults method which are :
  *         - typeName {string}
  *                    The typeName of the actor.
  *         - observationTopic {string}
  *                            The topic which this actor listens to via
  *                            Notification Observers.
  *         - storeObjectType {string}
  *                           The RetVal type of the store object of this actor.
  * @param {object} overrides
  *        All the methods which you want to be differnt from the ones in
  *        StorageActors.defaults method plus the required ones described there.
  */
 StorageActors.createActor = function(options = {}, overrides = {}) {
   let actorObject = StorageActors.defaults(
     options.typeName,
     options.observationTopic || null,
     options.storeObjectType
   );
   for (let key in overrides) {
     actorObject[key] = overrides[key];
   }
   let actor = protocol.ActorClass(actorObject);
   let front = protocol.FrontClass(actor, {
     form: function(form, detail) {
       if (detail === "actorid") {
         this.actorID = form;
         return null;
       }
       this.actorID = form.actor;
       this.hosts = form.hosts;
       return null;
     }
   });
   storageTypePool.set(actorObject.typeName, actor);
 }
 /**
  * The Cookies actor and front.
  */
 StorageActors.createActor({
   typeName: "cookies",
   storeObjectType: "cookiestoreobject"
 }, {
   initialize: function(storageActor) {
     protocol.Actor.prototype.initialize.call(this, null);
     this.storageActor = storageActor;
     this.populateStoresForHosts();
     Services.obs.addObserver(this, "cookie-changed", false);
     Services.obs.addObserver(this, "http-on-response-set-cookie", false);
     this.onWindowReady = this.onWindowReady.bind(this);
     this.onWindowDestroyed = this.onWindowDestroyed.bind(this);
     events.on(this.storageActor, "window-ready", this.onWindowReady);
     events.on(this.storageActor, "window-destroyed", this.onWindowDestroyed);
   },
   destroy: function() {
     this.hostVsStores = null;
     Services.obs.removeObserver(this, "cookie-changed", false);
     Services.obs.removeObserver(this, "http-on-response-set-cookie", false);
     events.off(this.storageActor, "window-ready", this.onWindowReady);
     events.off(this.storageActor, "window-destroyed", this.onWindowDestroyed);
   },
   /**
    * Given a cookie object, figure out all the matching hosts from the page that
    * the cookie belong to.
    */
   getMatchingHosts: function(cookies) {
     if (!cookies.length) {
       cookies = [cookies];
     }
     let hosts = new Set();
     for (let host of this.hosts) {
       for (let cookie of cookies) {
         if (this.isCookieAtHost(cookie, host)) {
           hosts.add(host);
         }
       }
     }
     return [...hosts];
   },
   /**
    * Given a cookie object and a host, figure out if the cookie is valid for
    * that host.
    */
   isCookieAtHost: function(cookie, host) {
     try {
       cookie = cookie.QueryInterface(Ci.nsICookie)
                      .QueryInterface(Ci.nsICookie2);
     } catch(ex) {
       return false;
     }
     if (cookie.host == null) {
       return host == null;
     }
     if (cookie.host.startsWith(".")) {
       return host.endsWith(cookie.host);
     }
     else {
       return cookie.host == host;
     }
   },
   toStoreObject: function(cookie) {
     if (!cookie) {
       return null;
     }
     return {
       name: cookie.name,
       path: cookie.path || "",
       host: cookie.host || "",
       expires: (cookie.expires || 0) * 1000, // because expires is in seconds
       creationTime: cookie.creationTime / 1000, // because it is in micro seconds
       lastAccessed: cookie.lastAccessed / 1000, // - do -
       value: new LongStringActor(this.conn, cookie.value || ""),
       isDomain: cookie.isDomain,
       isSecure: cookie.isSecure,
       isHttpOnly: cookie.isHttpOnly
     }
   },
   populateStoresForHost: function(host) {
     this.hostVsStores.set(host, new Map());
     let cookies = Services.cookies.getCookiesFromHost(host);
     while (cookies.hasMoreElements()) {
       let cookie = cookies.getNext().QueryInterface(Ci.nsICookie)
                           .QueryInterface(Ci.nsICookie2);
       if (this.isCookieAtHost(cookie, host)) {
         this.hostVsStores.get(host).set(cookie.name, cookie);
       }
     }
   },
   /**
    * Converts the raw cookie string returned in http request's response header
    * to a nsICookie compatible object.
    *
    * @param {string} cookieString
    *        The raw cookie string coming from response header.
    * @param {string} domain
    *        The domain of the url of the nsiChannel the cookie corresponds to.
    *        This will be used when the cookie string does not have a domain.
    *
    * @returns {[object]}
    *          An array of nsICookie like objects representing the cookies.
    */
   parseCookieString: function(cookieString, domain) {
     /**
      * Takes a date string present in raw cookie string coming from http
      * request's response headers and returns the number of milliseconds elapsed
      * since epoch. If the date string is undefined, its probably a session
      * cookie so return 0.
      */
     let parseDateString = dateString => {
       return dateString ? new Date(dateString.replace(/-/g, " ")).getTime(): 0;
     };
     let cookies = [];
     for (let string of cookieString.split("\n")) {
       let keyVals = {}, name = null;
       for (let keyVal of string.split(/;\s*/)) {
         let tokens = keyVal.split(/\s*=\s*/);
         if (!name) {
           name = tokens[0];
         }
         else {
           tokens[0] = tokens[0].toLowerCase();
         }
         keyVals[tokens.splice(0, 1)[0]] = tokens.join("=");
       }
       let expiresTime = parseDateString(keyVals.expires);
       keyVals.domain = keyVals.domain || domain;
       cookies.push({
         name: name,
         value: keyVals[name] || "",
         path: keyVals.path,
         host: keyVals.domain,
         expires: expiresTime/1000, // seconds, to match with nsiCookie.expires
         lastAccessed: expiresTime * 1000,
         // microseconds, to match with nsiCookie.lastAccessed
         creationTime: expiresTime * 1000,
         // microseconds, to match with nsiCookie.creationTime
         isHttpOnly: true,
         isSecure: keyVals.secure != null,
         isDomain: keyVals.domain.startsWith("."),
       });
     }
     return cookies;
   },
   /**
    * Notification observer for topics "http-on-response-set-cookie" and
    * "cookie-change".
    *
    * @param subject
    *        {nsiChannel} The channel associated to the SET-COOKIE response
    *        header in case of "http-on-response-set-cookie" topic.
    *        {nsiCookie|[nsiCookie]} A single nsiCookie object or a list of it
    *        depending on the action. Array is only in case of "batch-deleted"
    *        action.
    * @param {string} topic
    *        The topic of the notification.
    * @param {string} action
    *        Additional data associated with the notification. Its the type of
    *        cookie change in case of "cookie-change" topic and the cookie string
    *        in case of "http-on-response-set-cookie" topic.
    */
   observe: function(subject, topic, action) {
     if (topic == "http-on-response-set-cookie") {
       // Some cookies got created as a result of http response header SET-COOKIE
       // subject here is an nsIChannel object referring to the http request.
       // We get the requestor of this channel and thus the content window.
       let channel = subject.QueryInterface(Ci.nsIChannel);
       let requestor = channel.notificationCallbacks ||
                       channel.loadGroup.notificationCallbacks;
       // requester can be null sometimes.
       let window = requestor ? requestor.getInterface(Ci.nsIDOMWindow): null;
       // Proceed only if this window is present on the currently targetted tab
       if (window && this.storageActor.isIncludedInTopLevelWindow(window)) {
         let host = this.getHostName(window.location);
         if (this.hostVsStores.has(host)) {
           let cookies = this.parseCookieString(action, channel.URI.host);
           let data = {};
           data[host] =  [];
           for (let cookie of cookies) {
             if (this.hostVsStores.get(host).has(cookie.name)) {
               continue;
             }
             this.hostVsStores.get(host).set(cookie.name, cookie);
             data[host].push(cookie.name);
           }
           if (data[host]) {
             this.storageActor.update("added", "cookies", data);
           }
         }
       }
       return null;
     }
     if (topic != "cookie-changed") {
       return null;
     }
     let hosts = this.getMatchingHosts(subject);
     let data = {};
     switch(action) {
       case "added":
       case "changed":
         if (hosts.length) {
           subject = subject.QueryInterface(Ci.nsICookie)
                            .QueryInterface(Ci.nsICookie2);
           for (let host of hosts) {
             this.hostVsStores.get(host).set(subject.name, subject);
             data[host] = [subject.name];
           }
           this.storageActor.update(action, "cookies", data);
         }
         break;
       case "deleted":
         if (hosts.length) {
           subject = subject.QueryInterface(Ci.nsICookie)
                            .QueryInterface(Ci.nsICookie2);
           for (let host of hosts) {
             this.hostVsStores.get(host).delete(subject.name);
             data[host] = [subject.name];
           }
           this.storageActor.update("deleted", "cookies", data);
         }
         break;
       case "batch-deleted":
         if (hosts.length) {
           for (let host of hosts) {
             let stores = [];
             for (let cookie of subject) {
               cookie = cookie.QueryInterface(Ci.nsICookie)
                              .QueryInterface(Ci.nsICookie2);
               this.hostVsStores.get(host).delete(cookie.name);
               stores.push(cookie.name);
             }
             data[host] = stores;
           }
           this.storageActor.update("deleted", "cookies", data);
         }
         break;
       case "cleared":
         this.storageActor.update("cleared", "cookies", hosts);
         break;
       case "reload":
         this.storageActor.update("reloaded", "cookies", hosts);
         break;
     }
     return null;
   },
 });
 /**
  * Helper method to create the overriden object required in
  * StorageActors.createActor for Local Storage and Session Storage.
  * This method exists as both Local Storage and Session Storage have almost
  * identical actors.
  */
 function getObjectForLocalOrSessionStorage(type) {
   return {
     getNamesForHost: function(host) {
       let storage = this.hostVsStores.get(host);
       return [key for (key in storage)];
     },
     getValuesForHost: function(host, name) {
       let storage = this.hostVsStores.get(host);
       if (name) {
         return [{name: name, value: storage.getItem(name)}];
       }
       return [{name: name, value: storage.getItem(name)} for (name in storage)];
     },
     getHostName: function(location) {
       if (!location.host) {
         return location.href;
       }
       return location.protocol + "//" + location.host;
     },
     populateStoresForHost: function(host, window) {
       try {
         this.hostVsStores.set(host, window[type]);
       } catch(ex) {
         // Exceptions happen when local or session storage is inaccessible
       }
       return null;
     },
     populateStoresForHosts: function() {
       this.hostVsStores = new Map();
       try {
         for (let window of this.windows) {
           this.hostVsStores.set(this.getHostName(window.location), window[type]);
         }
       } catch(ex) {
         // Exceptions happen when local or session storage is inaccessible
       }
       return null;
     },
     observe: function(subject, topic, data) {
       if (topic != "dom-storage2-changed" || data != type) {
         return null;
       }
       let host = this.getSchemaAndHost(subject.url);
       if (!this.hostVsStores.has(host)) {
         return null;
       }
       let action = "changed";
       if (subject.key == null) {
         return this.storageActor.update("cleared", type, [host]);
       }
       else if (subject.oldValue == null) {
         action = "added";
       }
       else if (subject.newValue == null) {
         action = "deleted";
       }
       let updateData = {};
       updateData[host] = [subject.key];
       return this.storageActor.update(action, type, updateData);
     },
     /**
      * Given a url, correctly determine its protocol + hostname part.
      */
     getSchemaAndHost: function(url) {
       let uri = Services.io.newURI(url, null, null);
       return uri.scheme + "://" + uri.hostPort;
     },
     toStoreObject: function(item) {
       if (!item) {
         return null;
       }
       return {
         name: item.name,
         value: new LongStringActor(this.conn, item.value || "")
       };
     },
   }
 };
 /**
  * The Local Storage actor and front.
  */
 StorageActors.createActor({
   typeName: "localStorage",
   observationTopic: "dom-storage2-changed",
   storeObjectType: "storagestoreobject"
 }, getObjectForLocalOrSessionStorage("localStorage"));
 /**
  * The Session Storage actor and front.
  */
 StorageActors.createActor({
   typeName: "sessionStorage",
   observationTopic: "dom-storage2-changed",
   storeObjectType: "storagestoreobject"
 }, getObjectForLocalOrSessionStorage("sessionStorage"));
 /**
  * Code related to the Indexed DB actor and front
  */
 // Metadata holder objects for various components of Indexed DB
 /**
  * Meta data object for a particular index in an object store
  *
  * @param {IDBIndex} index
  *        The particular index from the object store.
  */
 function IndexMetadata(index) {
   this._name = index.name;
   this._keyPath = index.keyPath;
   this._unique = index.unique;
   this._multiEntry = index.multiEntry;
 }
 IndexMetadata.prototype = {
   toObject: function() {
     return {
       name: this._name,
       keyPath: this._keyPath,
       unique: this._unique,
       multiEntry: this._multiEntry
     };
   }
 };
 /**
  * Meta data object for a particular object store in a db
  *
  * @param {IDBObjectStore} objectStore
  *        The particular object store from the db.
  */
 function ObjectStoreMetadata(objectStore) {
   this._name = objectStore.name;
   this._keyPath = objectStore.keyPath;
   this._autoIncrement = objectStore.autoIncrement;
   this._indexes = new Map();
   for (let i = 0; i < objectStore.indexNames.length; i++) {
     let index = objectStore.index(objectStore.indexNames[i]);
     this._indexes.set(index, new IndexMetadata(index));
   }
 }
 ObjectStoreMetadata.prototype = {
   toObject: function() {
     return {
       name: this._name,
       keyPath: this._keyPath,
       autoIncrement: this._autoIncrement,
       indexes: JSON.stringify(
         [index.toObject() for (index of this._indexes.values())]
       )
     };
   }
 };
 /**
  * Meta data object for a particular indexed db in a host.
  *
  * @param {string} origin
  *        The host associated with this indexed db.
  * @param {IDBDatabase} db
  *        The particular indexed db.
  */
 function DatabaseMetadata(origin, db) {
   this._origin = origin;
   this._name = db.name;
   this._version = db.version;
   this._objectStores = new Map();
   if (db.objectStoreNames.length) {
     let transaction = db.transaction(db.objectStoreNames, "readonly");
     for (let i = 0; i < transaction.objectStoreNames.length; i++) {
       let objectStore =
         transaction.objectStore(transaction.objectStoreNames[i]);
       this._objectStores.set(transaction.objectStoreNames[i],
                              new ObjectStoreMetadata(objectStore));
     }
   }
 };
 DatabaseMetadata.prototype = {
   get objectStores() {
     return this._objectStores;
   },
   toObject: function() {
     return {
       name: this._name,
       origin: this._origin,
       version: this._version,
       objectStores: this._objectStores.size
     };
   }
 };
 StorageActors.createActor({
   typeName: "indexedDB",
   storeObjectType: "idbstoreobject"
 }, {
   initialize: function(storageActor) {
     protocol.Actor.prototype.initialize.call(this, null);
     if (!global.indexedDB) {
       let idbManager = Cc["@mozilla.org/dom/indexeddb/manager;1"]
                          .getService(Ci.nsIIndexedDatabaseManager);
       idbManager.initWindowless(global);
     }
     this.objectsSize = {};
     this.storageActor = storageActor;
     this.onWindowReady = this.onWindowReady.bind(this);
     this.onWindowDestroyed = this.onWindowDestroyed.bind(this);
     events.on(this.storageActor, "window-ready", this.onWindowReady);
     events.on(this.storageActor, "window-destroyed", this.onWindowDestroyed);
   },
   destroy: function() {
     this.hostVsStores = null;
     this.objectsSize = null;
     events.off(this.storageActor, "window-ready", this.onWindowReady);
     events.off(this.storageActor, "window-destroyed", this.onWindowDestroyed);
   },
   getHostName: function(location) {
     if (!location.host) {
       return location.href;
     }
     return location.protocol + "//" + location.host;
   },
   /**
    * This method is overriden and left blank as for indexedDB, this operation
    * cannot be performed synchronously. Thus, the preListStores method exists to
    * do the same task asynchronously.
    */
   populateStoresForHosts: function() {
   },
   getNamesForHost: function(host) {
     let names = [];
     for (let [dbName, metaData] of this.hostVsStores.get(host)) {
       for (let objectStore of metaData.objectStores.keys()) {
         names.push(JSON.stringify([dbName, objectStore]));
       }
     }
     return names;
   },
   /**
    * Returns all or requested entries from a particular objectStore from the db
    * in the given host.
    *
    * @param {string} host
    *        The given host.
    * @param {string} dbName
    *        The name of the indexed db from the above host.
    * @param {string} objectStore
    *        The name of the object store from the above db.
    * @param {string} id
    *        id of the requested entry from the above object store.
    *        null if all entries from the above object store are requested.
    * @param {string} index
    *        name of the IDBIndex to be iterated on while fetching entries.
    *        null or "name" if no index is to be iterated.
    * @param {number} offset
    *        ofsset of the entries to be fetched.
    * @param {number} size
    *        The intended size of the entries to be fetched.
    */
   getObjectStoreData:
   function(host, dbName, objectStore, id, index, offset, size) {
     let request = this.openWithOrigin(host, dbName);
     let success = Promise.defer();
     let data = [];
     if (!size || size > MAX_STORE_OBJECT_COUNT) {
       size = MAX_STORE_OBJECT_COUNT;
     }
     request.onsuccess = event => {
       let db = event.target.result;
       let transaction = db.transaction(objectStore, "readonly");
       let source = transaction.objectStore(objectStore);
       if (index && index != "name") {
         source = source.index(index);
       }
       source.count().onsuccess = event => {
         let count = event.target.result;
         this.objectsSize[host + dbName + objectStore + index] = count;
         if (!offset) {
           offset = 0;
         }
         else if (offset > count) {
           db.close();
           success.resolve([]);
           return;
         }
         if (id) {
           source.get(id).onsuccess = event => {
             db.close();
             success.resolve([{name: id, value: event.target.result}]);
           };
         }
         else {
           source.openCursor().onsuccess = event => {
             let cursor = event.target.result;
             if (!cursor || data.length >= size) {
               db.close();
               success.resolve(data);
               return;
             }
             if (offset-- <= 0) {
               data.push({name: cursor.key, value: cursor.value});
             }
             cursor.continue();
           };
         }
       };
     };
     request.onerror = () => {
       db.close();
       success.resolve([]);
     };
     return success.promise;
   },
   /**
    * Returns the total number of entries for various types of requests to
    * getStoreObjects for Indexed DB actor.
    *
    * @param {string} host
    *        The host for the request.
    * @param {array:string} names
    *        Array of stringified name objects for indexed db actor.
    *        The request type depends on the length of any parsed entry from this
    *        array. 0 length refers to request for the whole host. 1 length
    *        refers to request for a particular db in the host. 2 length refers
    *        to a particular object store in a db in a host. 3 length refers to
    *        particular items of an object store in a db in a host.
    * @param {object} options
    *        An options object containing following properties:
    *         - index {string} The IDBIndex for the object store in the db.
    */
   getObjectsSize: function(host, names, options) {
     // In Indexed DB, we are interested in only the first name, as the pattern
     // should follow in all entries.
     let name = names[0];
     let parsedName = JSON.parse(name);
     if (parsedName.length == 3) {
       // This is the case where specific entries from an object store were
       // requested
       return names.length;
     }
     else if (parsedName.length == 2) {
       // This is the case where all entries from an object store are requested.
       let index = options.index;
       let [db, objectStore] = parsedName;
       if (this.objectsSize[host + db + objectStore + index]) {
         return this.objectsSize[host + db + objectStore + index];
       }
     }
     else if (parsedName.length == 1) {
       // This is the case where details of all object stores in a db are
       // requested.
       if (this.hostVsStores.has(host) &&
           this.hostVsStores.get(host).has(parsedName[0])) {
         return this.hostVsStores.get(host).get(parsedName[0]).objectStores.size;
       }
     }
     else if (!parsedName || !parsedName.length) {
       // This is the case were details of all dbs in a host are requested.
       if (this.hostVsStores.has(host)) {
         return this.hostVsStores.get(host).size;
       }
     }
     return 0;
   },
   getValuesForHost: async(function*(host, name = "null", options) {
     name = JSON.parse(name);
     if (!name || !name.length) {
       // This means that details about the db in this particular host are
       // requested.
       let dbs = [];
       if (this.hostVsStores.has(host)) {
         for (let [dbName, db] of this.hostVsStores.get(host)) {
           dbs.push(db.toObject());
         }
       }
       return dbs;
     }
     let [db, objectStore, id] = name;
     if (!objectStore) {
       // This means that details about all the object stores in this db are
       // requested.
       let objectStores = [];
       if (this.hostVsStores.has(host) && this.hostVsStores.get(host).has(db)) {
         for (let objectStore of this.hostVsStores.get(host).get(db).objectStores) {
           objectStores.push(objectStore[1].toObject());
         }
       }
       return objectStores;
     }
     // Get either all entries from the object store, or a particular id
     return yield this.getObjectStoreData(host, db, objectStore, id,
                                          options.index, options.size);
   }),
   /**
    * Purpose of this method is same as populateStoresForHosts but this is async.
    * This exact same operation cannot be performed in populateStoresForHosts
    * method, as that method is called in initialize method of the actor, which
    * cannot be asynchronous.
    */
   preListStores: async(function*() {
     this.hostVsStores = new Map();
     for (let host of this.hosts) {
       yield this.populateStoresForHost(host);
     }
   }),
   populateStoresForHost: async(function*(host) {
     let storeMap = new Map();
     for (let name of (yield this.getDBNamesForHost(host))) {
       storeMap.set(name, yield this.getDBMetaData(host, name));
     }
     this.hostVsStores.set(host, storeMap);
   }),
   /**
    * Removes any illegal characters from the host name to make it a valid file
    * name.
    */
   getSanitizedHost: function(host) {
     return host.replace(ILLEGAL_CHAR_REGEX, "+");
   },
   /**
    * Opens an indexed db connection for the given `host` and database `name`.
    */
   openWithOrigin: function(host, name) {
     let principal;
     if (/^(about:|chrome:)/.test(host)) {
       principal = Services.scriptSecurityManager.getSystemPrincipal();
     }
     else {
       let uri = Services.io.newURI(host, null, null);
       principal = Services.scriptSecurityManager.getCodebasePrincipal(uri);
     }
     return indexedDB.openForPrincipal(principal, name);
   },
   /**
    * Fetches and stores all the metadata information for the given database
    * `name` for the given `host`. The stored metadata information is of
    * `DatabaseMetadata` type.
    */
   getDBMetaData: function(host, name) {
     let request = this.openWithOrigin(host, name);
     let success = Promise.defer();
     request.onsuccess = event => {
       let db = event.target.result;
       let dbData = new DatabaseMetadata(host, db);
       db.close();
       success.resolve(dbData);
     };
     request.onerror = event => {
       console.error("Error opening indexeddb database " + name + " for host " +
                     host);
       success.resolve(null);
     };
     return success.promise;
   },
   /**
    * Retrives the proper indexed db database name from the provided .sqlite file
    * location.
    */
   getNameFromDatabaseFile: async(function*(path) {
     let connection = null;
     let retryCount = 0;
     // Content pages might be having an open transaction for the same indexed db
     // which this sqlite file belongs to. In that case, sqlite.openConnection
     // will throw. Thus we retey for some time to see if lock is removed.
     while (!connection && retryCount++ < 25) {
       try {
         connection = yield Sqlite.openConnection({ path: path });
       }
       catch (ex) {
         // Continuously retrying is overkill. Waiting for 100ms before next try
         yield sleep(100);
       }
     }
     if (!connection) {
       return null;
     }
     let rows = yield connection.execute("SELECT name FROM database");
     if (rows.length != 1) {
       return null;
     }
     let name = rows[0].getResultByName("name");
     yield connection.close();
     return name;
   }),
   /**
    * Fetches all the databases and their metadata for the given `host`.
    */
   getDBNamesForHost: async(function*(host) {
     let sanitizedHost = this.getSanitizedHost(host);
     let directory = OS.Path.join(OS.Constants.Path.profileDir, "storage",
                                  "persistent", sanitizedHost, "idb");
     let exists = yield OS.File.exists(directory);
     if (!exists && host.startsWith("about:")) {
       // try for moz-safe-about directory
       sanitizedHost = this.getSanitizedHost("moz-safe-" + host);
       directory = OS.Path.join(OS.Constants.Path.profileDir, "storage",
                                "persistent", sanitizedHost, "idb");
       exists = yield OS.File.exists(directory);
     }
     if (!exists) {
       return [];
     }
     let names = [];
     let dirIterator = new OS.File.DirectoryIterator(directory);
     try {
       yield dirIterator.forEach(file => {
         // Skip directories.
         if (file.isDir) {
           return null;
         }
         // Skip any non-sqlite files.
         if (!file.name.endsWith(".sqlite")) {
           return null;
         }
         return this.getNameFromDatabaseFile(file.path).then(name => {
           if (name) {
             names.push(name);
           }
           return null;
         });
       });
     }
     finally {
       dirIterator.close();
     }
     return names;
   }),
   /**
    * Returns the over-the-wire implementation of the indexed db entity.
    */
   toStoreObject: function(item) {
     if (!item) {
       return null;
     }
     if (item.indexes) {
       // Object store meta data
       return {
         objectStore: item.name,
         keyPath: item.keyPath,
         autoIncrement: item.autoIncrement,
         indexes: item.indexes
       };
     }
     if (item.objectStores) {
       // DB meta data
       return {
         db: item.name,
         origin: item.origin,
         version: item.version,
         objectStores: item.objectStores
       };
     }
     // Indexed db entry
     return {
       name: item.name,
       value: new LongStringActor(this.conn, JSON.stringify(item.value))
     };
   },
   form: function(form, detail) {
     if (detail === "actorid") {
       return this.actorID;
     }
     let hosts = {};
     for (let host of this.hosts) {
       hosts[host] = this.getNamesForHost(host);
     }
     return {
       actor: this.actorID,
       hosts: hosts
     };
   },
 });
 /**
  * The main Storage Actor.
  */
 let StorageActor = exports.StorageActor = protocol.ActorClass({
   typeName: "storage",
   get window() {
     return this.parentActor.window;
   },
   get document() {
     return this.parentActor.window.document;
   },
   get windows() {
     return this.childWindowPool;
   },
   /**
    * List of event notifications that the server can send to the client.
    *
    *  - stores-update : When any store object in any storage type changes.
    *  - stores-cleared : When all the store objects are removed.
    *  - stores-reloaded : When all stores are reloaded. This generally mean that
    *                      we should refetch everything again.
    */
   events: {
     "stores-update": {
       type: "storesUpdate",
       data: Arg(0, "storeUpdateObject")
     },
     "stores-cleared": {
       type: "storesCleared",
       data: Arg(0, "json")
     },
     "stores-reloaded": {
       type: "storesRelaoded",
       data: Arg(0, "json")
     }
   },
   initialize: function (conn, tabActor) {
     protocol.Actor.prototype.initialize.call(this, null);
     this.conn = conn;
     this.parentActor = tabActor;
     this.childActorPool = new Map();
     this.childWindowPool = new Set();
     // Fetch all the inner iframe windows in this tab.
     this.fetchChildWindows(this.parentActor.docShell);
     // Initialize the registered store types
     for (let [store, actor] of storageTypePool) {
       this.childActorPool.set(store, new actor(this));
     }
     // Notifications that help us keep track of newly added windows and windows
     // that got removed
     Services.obs.addObserver(this, "content-document-global-created", false);
     Services.obs.addObserver(this, "inner-window-destroyed", false);
     this.onPageChange = this.onPageChange.bind(this);
     tabActor.browser.addEventListener("pageshow", this.onPageChange, true);
     tabActor.browser.addEventListener("pagehide", this.onPageChange, true);
     this.destroyed = false;
     this.boundUpdate = {};
     // The time which periodically flushes and transfers the updated store
     // objects.
     this.updateTimer = Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer);
     this.updateTimer.initWithCallback(this , UPDATE_INTERVAL,
       Ci.nsITimer.TYPE_REPEATING_PRECISE_CAN_SKIP);
     // Layout helper for window.parent and window.top helper methods that work
     // accross devices.
     this.layoutHelper = new LayoutHelpers(this.window);
   },
   destroy: function() {
     this.updateTimer.cancel();
     this.updateTimer = null;
     this.layoutHelper = null;
     // Remove observers
     Services.obs.removeObserver(this, "content-document-global-created", false);
     Services.obs.removeObserver(this, "inner-window-destroyed", false);
     this.destroyed = true;
     if (this.parentActor.browser) {
       this.parentActor.browser.removeEventListener(
         "pageshow", this.onPageChange, true);
       this.parentActor.browser.removeEventListener(
         "pagehide", this.onPageChange, true);
     }
     // Destroy the registered store types
     for (let actor of this.childActorPool.values()) {
       actor.destroy();
     }
     this.childActorPool.clear();
     this.childWindowPool.clear();
     this.childWindowPool = this.childActorPool = null;
   },
   /**
    * Given a docshell, recursively find otu all the child windows from it.
    *
    * @param {nsIDocShell} item
    *        The docshell from which all inner windows need to be extracted.
    */
   fetchChildWindows: function(item) {
     let docShell = item.QueryInterface(Ci.nsIDocShell)
                        .QueryInterface(Ci.nsIDocShellTreeItem);
     if (!docShell.contentViewer) {
       return null;
     }
     let window = docShell.contentViewer.DOMDocument.defaultView;
     if (window.location.href == "about:blank") {
       // Skip out about:blank windows as Gecko creates them multiple times while
       // creating any global.
       return null;
     }
     this.childWindowPool.add(window);
     for (let i = 0; i < docShell.childCount; i++) {
       let child = docShell.getChildAt(i);
       this.fetchChildWindows(child);
     }
     return null;
   },
   isIncludedInTopLevelWindow: function(window) {
     return this.layoutHelper.isIncludedInTopLevelWindow(window);
   },
   getWindowFromInnerWindowID: function(innerID) {
     innerID = innerID.QueryInterface(Ci.nsISupportsPRUint64).data;
     for (let win of this.childWindowPool.values()) {
       let id = win.QueryInterface(Ci.nsIInterfaceRequestor)
                    .getInterface(Ci.nsIDOMWindowUtils)
                    .currentInnerWindowID;
       if (id == innerID) {
         return win;
       }
     }
     return null;
   },
   /**
    * Event handler for any docshell update. This lets us figure out whenever
    * any new window is added, or an existing window is removed.
    */
   observe: function(subject, topic, data) {
     if (subject.location &&
         (!subject.location.href || subject.location.href == "about:blank")) {
       return null;
     }
     if (topic == "content-document-global-created" &&
         this.isIncludedInTopLevelWindow(subject)) {
       this.childWindowPool.add(subject);
       events.emit(this, "window-ready", subject);
     }
     else if (topic == "inner-window-destroyed") {
       let window = this.getWindowFromInnerWindowID(subject);
       if (window) {
         this.childWindowPool.delete(window);
         events.emit(this, "window-destroyed", window);
       }
     }
     return null;
   },
   /**
    * Called on "pageshow" or "pagehide" event on the chromeEventHandler of
    * current tab.
    *
    * @param {event} The event object passed to the handler. We are using these
    *        three properties from the event:
    *         - target {document} The document corresponding to the event.
    *         - type {string} Name of the event - "pageshow" or "pagehide".
    *         - persisted {boolean} true if there was no
    *                     "content-document-global-created" notification along
    *                     this event.
    */
   onPageChange: function({target, type, persisted}) {
     if (this.destroyed) {
       return;
     }
     let window = target.defaultView;
     if (type == "pagehide" && this.childWindowPool.delete(window)) {
       events.emit(this, "window-destroyed", window)
     }
     else if (type == "pageshow" && persisted  && window.location.href &&
              window.location.href != "about:blank" &&
              this.isIncludedInTopLevelWindow(window)) {
       this.childWindowPool.add(window);
       events.emit(this, "window-ready", window);
     }
   },
   /**
    * Lists the available hosts for all the registered storage types.
    *
    * @returns {object} An object containing with the following structure:
    *  - <storageType> : [{
    *      actor: <actorId>,
    *      host: <hostname>
    *    }]
    */
   listStores: method(async(function*() {
     let toReturn = {};
     for (let [name, value] of this.childActorPool) {
       if (value.preListStores) {
         yield value.preListStores();
       }
       toReturn[name] = value;
     }
     return toReturn;
   }), {
     response: RetVal(types.addDictType("storelist", getRegisteredTypes()))
   }),
   /**
    * Notifies the client front with the updates in stores at regular intervals.
    */
   notify: function() {
     if (!this.updatePending || this.updatingUpdateObject) {
       return null;
     }
     events.emit(this, "stores-update", this.boundUpdate);
     this.boundUpdate = {};
     this.updatePending = false;
     return null;
   },
   /**
    * This method is called by the registered storage types so as to tell the
    * Storage Actor that there are some changes in the stores. Storage Actor then
    * notifies the client front about these changes at regular (UPDATE_INTERVAL)
    * interval.
    *
    * @param {string} action
    *        The type of change. One of "added", "changed" or "deleted"
    * @param {string} storeType
    *        The storage actor in which this change has occurred.
    * @param {object} data
    *        The update object. This object is of the following format:
    *         - {
    *             <host1>: [<store_names1>, <store_name2>...],
    *             <host2>: [<store_names34>...],
    *           }
    *           Where host1, host2 are the host in which this change happened and
    *           [<store_namesX] is an array of the names of the changed store
    *           objects. Leave it empty if the host was completely removed.
    *        When the action is "reloaded" or "cleared", `data` is an array of
    *        hosts for which the stores were cleared or reloaded.
    */
   update: function(action, storeType, data) {
     if (action == "cleared" || action == "reloaded") {
       let toSend = {};
       toSend[storeType] = data
       events.emit(this, "stores-" + action, toSend);
       return null;
     }
     this.updatingUpdateObject = true;
     if (!this.boundUpdate[action]) {
       this.boundUpdate[action] = {};
     }
     if (!this.boundUpdate[action][storeType]) {
       this.boundUpdate[action][storeType] = {};
     }
     this.updatePending = true;
     for (let host in data) {
       if (!this.boundUpdate[action][storeType][host] || action == "deleted") {
         this.boundUpdate[action][storeType][host] = data[host];
       }
       else {
         this.boundUpdate[action][storeType][host] =
         this.boundUpdate[action][storeType][host].concat(data[host]);
       }
     }
     if (action == "added") {
       // If the same store name was previously deleted or changed, but now is
       // added somehow, dont send the deleted or changed update.
       this.removeNamesFromUpdateList("deleted", storeType, data);
       this.removeNamesFromUpdateList("changed", storeType, data);
     }
     else if (action == "changed" && this.boundUpdate.added &&
              this.boundUpdate.added[storeType]) {
       // If something got added and changed at the same time, then remove those
       // items from changed instead.
       this.removeNamesFromUpdateList("changed", storeType,
                                      this.boundUpdate.added[storeType]);
     }
     else if (action == "deleted") {
       // If any item got delete, or a host got delete, no point in sending
       // added or changed update
       this.removeNamesFromUpdateList("added", storeType, data);
       this.removeNamesFromUpdateList("changed", storeType, data);
       for (let host in data) {
         if (data[host].length == 0 && this.boundUpdate.added &&
             this.boundUpdate.added[storeType] &&
             this.boundUpdate.added[storeType][host]) {
           delete this.boundUpdate.added[storeType][host];
         }
         if (data[host].length == 0 && this.boundUpdate.changed &&
             this.boundUpdate.changed[storeType] &&
             this.boundUpdate.changed[storeType][host]) {
           delete this.boundUpdate.changed[storeType][host];
         }
       }
     }
     this.updatingUpdateObject = false;
     return null;
   },
   /**
    * This method removes data from the this.boundUpdate object in the same
    * manner like this.update() adds data to it.
    *
    * @param {string} action
    *        The type of change. One of "added", "changed" or "deleted"
    * @param {string} storeType
    *        The storage actor for which you want to remove the updates data.
    * @param {object} data
    *        The update object. This object is of the following format:
    *         - {
    *             <host1>: [<store_names1>, <store_name2>...],
    *             <host2>: [<store_names34>...],
    *           }
    *           Where host1, host2 are the hosts which you want to remove and
    *           [<store_namesX] is an array of the names of the store objects.
    */
   removeNamesFromUpdateList: function(action, storeType, data) {
     for (let host in data) {
       if (this.boundUpdate[action] && this.boundUpdate[action][storeType] &&
           this.boundUpdate[action][storeType][host]) {
         for (let name in data[host]) {
           let index = this.boundUpdate[action][storeType][host].indexOf(name);
           if (index > -1) {
             this.boundUpdate[action][storeType][host].splice(index, 1);
           }
         }
         if (!this.boundUpdate[action][storeType][host].length) {
           delete this.boundUpdate[action][storeType][host];
         }
       }
     }
     return null;
   }
 });
 /**
  * Front for the Storage Actor.
  */
 let StorageFront = exports.StorageFront = protocol.FrontClass(StorageActor, {
   initialize: function(client, tabForm) {
     protocol.Front.prototype.initialize.call(this, client);
     this.actorID = tabForm.storageActor;
     client.addActorPool(this);
     this.manage(this);
   }
 });