diff -r 000000000000 -r 6474c204b198 toolkit/devtools/server/actors/storage.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/devtools/server/actors/storage.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,1708 @@
+/* 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);
+  }
+});