The Tor Browser: toolkit/components/contentprefs/nsContentPrefService.js@6474c204b198 (annotated)

toolkit/components/contentprefs/nsContentPrefService.js@6474c204b198 (annotated)

toolkit/components/contentprefs/nsContentPrefService.js

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 /* 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/. */
 const Ci = Components.interfaces;
 const Cc = Components.classes;
 const Cr = Components.results;
 const Cu = Components.utils;
 const CACHE_MAX_GROUP_ENTRIES = 100;
 Cu.import("resource://gre/modules/XPCOMUtils.jsm");
 /**
  * Remotes the service. All the remoting/electrolysis code is in here,
  * so the regular service code below remains uncluttered and maintainable.
  */
 function electrolify(service) {
   // FIXME: For now, use the wrappedJSObject hack, until bug
   //        593407 which will clean that up.
   //        Note that we also use this in the xpcshell tests, separately.
   service.wrappedJSObject = service;
   var appInfo = Cc["@mozilla.org/xre/app-info;1"];
   if (appInfo && appInfo.getService(Ci.nsIXULRuntime).processType !=
       Ci.nsIXULRuntime.PROCESS_TYPE_DEFAULT)
   {
     // Child process
     service._dbInit = function(){}; // No local DB
   }
 }
 function ContentPrefService() {
   electrolify(this);
   // If this throws an exception, it causes the getService call to fail,
   // but the next time a consumer tries to retrieve the service, we'll try
   // to initialize the database again, which might work if the failure
   // was due to a temporary condition (like being out of disk space).
   this._dbInit();
   this._observerSvc.addObserver(this, "last-pb-context-exited", false);
   // Observe shutdown so we can shut down the database connection.
   this._observerSvc.addObserver(this, "xpcom-shutdown", false);
 }
 Cu.import("resource://gre/modules/ContentPrefStore.jsm");
 const cache = new ContentPrefStore();
 cache.set = function CPS_cache_set(group, name, val) {
   Object.getPrototypeOf(this).set.apply(this, arguments);
   let groupCount = Object.keys(this._groups).length;
   if (groupCount >= CACHE_MAX_GROUP_ENTRIES) {
     // Clean half of the entries
     for (let [group, name, ] in this) {
       this.remove(group, name);
       groupCount--;
       if (groupCount < CACHE_MAX_GROUP_ENTRIES / 2)
         break;
     }
   }
 };
 const privModeStorage = new ContentPrefStore();
 ContentPrefService.prototype = {
   //**************************************************************************//
   // XPCOM Plumbing
   classID: Components.ID("{e3f772f3-023f-4b32-b074-36cf0fd5d414}"),
   QueryInterface: function CPS_QueryInterface(iid) {
     let supportedIIDs = [
       Ci.nsIContentPrefService,
       Ci.nsIFrameMessageListener,
       Ci.nsISupports,
     ];
     if (supportedIIDs.some(function (i) iid.equals(i)))
       return this;
     if (iid.equals(Ci.nsIContentPrefService2)) {
       if (!this._contentPrefService2) {
         let s = {};
         Cu.import("resource://gre/modules/ContentPrefService2.jsm", s);
         this._contentPrefService2 = new s.ContentPrefService2(this);
       }
       return this._contentPrefService2;
     }
     throw Cr.NS_ERROR_NO_INTERFACE;
   },
   //**************************************************************************//
   // Convenience Getters
   // Observer Service
   __observerSvc: null,
   get _observerSvc() {
     if (!this.__observerSvc)
       this.__observerSvc = Cc["@mozilla.org/observer-service;1"].
                            getService(Ci.nsIObserverService);
     return this.__observerSvc;
   },
   // Console Service
   __consoleSvc: null,
   get _consoleSvc() {
     if (!this.__consoleSvc)
       this.__consoleSvc = Cc["@mozilla.org/consoleservice;1"].
                           getService(Ci.nsIConsoleService);
     return this.__consoleSvc;
   },
   // Preferences Service
   __prefSvc: null,
   get _prefSvc() {
     if (!this.__prefSvc)
       this.__prefSvc = Cc["@mozilla.org/preferences-service;1"].
                        getService(Ci.nsIPrefBranch);
     return this.__prefSvc;
   },
   //**************************************************************************//
   // Destruction
   _destroy: function ContentPrefService__destroy() {
     this._observerSvc.removeObserver(this, "xpcom-shutdown");
     this._observerSvc.removeObserver(this, "last-pb-context-exited");
     // Finalize statements which may have been used asynchronously.
     // FIXME(696499): put them in an object cache like other components.
     if (this.__stmtSelectPrefID) {
       this.__stmtSelectPrefID.finalize();
       this.__stmtSelectPrefID = null;
     }
     if (this.__stmtSelectGlobalPrefID) {
       this.__stmtSelectGlobalPrefID.finalize();
       this.__stmtSelectGlobalPrefID = null;
     }
     if (this.__stmtInsertPref) {
       this.__stmtInsertPref.finalize();
       this.__stmtInsertPref = null;
     }
     if (this.__stmtInsertGroup) {
       this.__stmtInsertGroup.finalize();
       this.__stmtInsertGroup = null;
     }
     if (this.__stmtInsertSetting) {
       this.__stmtInsertSetting.finalize();
       this.__stmtInsertSetting = null;
     }
     if (this.__stmtSelectGroupID) {
       this.__stmtSelectGroupID.finalize();
       this.__stmtSelectGroupID = null;
     }
     if (this.__stmtSelectSettingID) {
       this.__stmtSelectSettingID.finalize();
       this.__stmtSelectSettingID = null;
     }
     if (this.__stmtSelectPref) {
       this.__stmtSelectPref.finalize();
       this.__stmtSelectPref = null;
     }
     if (this.__stmtSelectGlobalPref) {
       this.__stmtSelectGlobalPref.finalize();
       this.__stmtSelectGlobalPref = null;
     }
     if (this.__stmtSelectPrefsByName) {
       this.__stmtSelectPrefsByName.finalize();
       this.__stmtSelectPrefsByName = null;
     }
     if (this.__stmtDeleteSettingIfUnused) {
       this.__stmtDeleteSettingIfUnused.finalize();
       this.__stmtDeleteSettingIfUnused = null;
     }
     if(this.__stmtSelectPrefs) {
       this.__stmtSelectPrefs.finalize();
       this.__stmtSelectPrefs = null;
     }
     if(this.__stmtDeleteGroupIfUnused) {
       this.__stmtDeleteGroupIfUnused.finalize();
       this.__stmtDeleteGroupIfUnused = null;
     }
     if (this.__stmtDeletePref) {
       this.__stmtDeletePref.finalize();
       this.__stmtDeletePref = null;
     }
     if (this.__stmtUpdatePref) {
       this.__stmtUpdatePref.finalize();
       this.__stmtUpdatePref = null;
     }
     if (this._contentPrefService2)
       this._contentPrefService2.destroy();
     this._dbConnection.asyncClose();
     // Delete references to XPCOM components to make sure we don't leak them
     // (although we haven't observed leakage in tests).  Also delete references
     // in _observers and _genericObservers to avoid cycles with those that
     // refer to us and don't remove themselves from those observer pools.
     for (var i in this) {
       try { this[i] = null }
       // Ignore "setting a property that has only a getter" exceptions.
       catch(ex) {}
     }
   },
   //**************************************************************************//
   // nsIObserver
   observe: function ContentPrefService_observe(subject, topic, data) {
     switch (topic) {
       case "xpcom-shutdown":
         this._destroy();
         break;
       case "last-pb-context-exited":
         this._privModeStorage.removeAll();
         break;
     }
   },
   //**************************************************************************//
   // in-memory cache and private-browsing stores
   _cache: cache,
   _privModeStorage: privModeStorage,
   //**************************************************************************//
   // nsIContentPrefService
   getPref: function ContentPrefService_getPref(aGroup, aName, aContext, aCallback) {
     warnDeprecated();
     if (!aName)
       throw Components.Exception("aName cannot be null or an empty string",
                                  Cr.NS_ERROR_ILLEGAL_VALUE);
     var group = this._parseGroupParam(aGroup);
     if (aContext && aContext.usePrivateBrowsing) {
       if (this._privModeStorage.has(group, aName)) {
         let value = this._privModeStorage.get(group, aName);
         if (aCallback) {
           this._scheduleCallback(function(){aCallback.onResult(value);});
           return;
         }
         return value;
       }
       // if we don't have a pref specific to this private mode browsing
       // session, to try to get one from normal mode
     }
     if (group == null)
       return this._selectGlobalPref(aName, aCallback);
     return this._selectPref(group, aName, aCallback);
   },
   setPref: function ContentPrefService_setPref(aGroup, aName, aValue, aContext) {
     warnDeprecated();
     // If the pref is already set to the value, there's nothing more to do.
     var currentValue = this.getPref(aGroup, aName, aContext);
     if (typeof currentValue != "undefined") {
       if (currentValue == aValue)
         return;
     }
     var group = this._parseGroupParam(aGroup);
     if (aContext && aContext.usePrivateBrowsing) {
       this._privModeStorage.setWithCast(group, aName, aValue);
       this._notifyPrefSet(group, aName, aValue);
       return;
     }
     var settingID = this._selectSettingID(aName) || this._insertSetting(aName);
     var groupID, prefID;
     if (group == null) {
       groupID = null;
       prefID = this._selectGlobalPrefID(settingID);
     }
     else {
       groupID = this._selectGroupID(group) || this._insertGroup(group);
       prefID = this._selectPrefID(groupID, settingID);
     }
     // Update the existing record, if any, or create a new one.
     if (prefID)
       this._updatePref(prefID, aValue);
     else
       this._insertPref(groupID, settingID, aValue);
     this._cache.setWithCast(group, aName, aValue);
     this._notifyPrefSet(group, aName, aValue);
   },
   hasPref: function ContentPrefService_hasPref(aGroup, aName, aContext) {
     warnDeprecated();
     // XXX If consumers end up calling this method regularly, then we should
     // optimize this to query the database directly.
     return (typeof this.getPref(aGroup, aName, aContext) != "undefined");
   },
   hasCachedPref: function ContentPrefService_hasCachedPref(aGroup, aName, aContext) {
     warnDeprecated();
     if (!aName)
       throw Components.Exception("aName cannot be null or an empty string",
                                  Cr.NS_ERROR_ILLEGAL_VALUE);
     let group = this._parseGroupParam(aGroup);
     let storage = aContext && aContext.usePrivateBrowsing ? this._privModeStorage: this._cache;
     return storage.has(group, aName);
   },
   removePref: function ContentPrefService_removePref(aGroup, aName, aContext) {
     warnDeprecated();
     // If there's no old value, then there's nothing to remove.
     if (!this.hasPref(aGroup, aName, aContext))
       return;
     var group = this._parseGroupParam(aGroup);
     if (aContext && aContext.usePrivateBrowsing) {
       this._privModeStorage.remove(group, aName);
       this._notifyPrefRemoved(group, aName);
       return;
     }
     var settingID = this._selectSettingID(aName);
     var groupID, prefID;
     if (group == null) {
       groupID = null;
       prefID = this._selectGlobalPrefID(settingID);
     }
     else {
       groupID = this._selectGroupID(group);
       prefID = this._selectPrefID(groupID, settingID);
     }
     this._deletePref(prefID);
     // Get rid of extraneous records that are no longer being used.
     this._deleteSettingIfUnused(settingID);
     if (groupID)
       this._deleteGroupIfUnused(groupID);
     this._cache.remove(group, aName);
     this._notifyPrefRemoved(group, aName);
   },
   removeGroupedPrefs: function ContentPrefService_removeGroupedPrefs(aContext) {
     warnDeprecated();
     // will not delete global preferences
     if (aContext && aContext.usePrivateBrowsing) {
         // keep only global prefs
         this._privModeStorage.removeAllGroups();
     }
     this._cache.removeAllGroups();
     this._dbConnection.beginTransaction();
     try {
       this._dbConnection.executeSimpleSQL("DELETE FROM prefs WHERE groupID IS NOT NULL");
       this._dbConnection.executeSimpleSQL("DELETE FROM groups");
       this._dbConnection.executeSimpleSQL(
         "DELETE FROM settings " +
         "WHERE id NOT IN (SELECT DISTINCT settingID FROM prefs)"
       );
       this._dbConnection.commitTransaction();
     }
     catch(ex) {
       this._dbConnection.rollbackTransaction();
       throw ex;
     }
   },
   removePrefsByName: function ContentPrefService_removePrefsByName(aName, aContext) {
     warnDeprecated();
     if (!aName)
       throw Components.Exception("aName cannot be null or an empty string",
                                  Cr.NS_ERROR_ILLEGAL_VALUE);
     if (aContext && aContext.usePrivateBrowsing) {
       for (let [group, name, ] in this._privModeStorage) {
         if (name === aName) {
           this._privModeStorage.remove(group, aName);
           this._notifyPrefRemoved(group, aName);
         }
       }
     }
     var settingID = this._selectSettingID(aName);
     if (!settingID)
       return;
     var selectGroupsStmt = this._dbCreateStatement(
       "SELECT groups.id AS groupID, groups.name AS groupName " +
       "FROM prefs " +
       "JOIN groups ON prefs.groupID = groups.id " +
       "WHERE prefs.settingID = :setting "
     );
     var groupNames = [];
     var groupIDs = [];
     try {
       selectGroupsStmt.params.setting = settingID;
       while (selectGroupsStmt.executeStep()) {
         groupIDs.push(selectGroupsStmt.row["groupID"]);
         groupNames.push(selectGroupsStmt.row["groupName"]);
       }
     }
     finally {
       selectGroupsStmt.reset();
     }
     if (this.hasPref(null, aName)) {
       groupNames.push(null);
     }
     this._dbConnection.executeSimpleSQL("DELETE FROM prefs WHERE settingID = " + settingID);
     this._dbConnection.executeSimpleSQL("DELETE FROM settings WHERE id = " + settingID);
     for (var i = 0; i < groupNames.length; i++) {
       this._cache.remove(groupNames[i], aName);
       if (groupNames[i]) // ie. not null, which will be last (and i == groupIDs.length)
         this._deleteGroupIfUnused(groupIDs[i]);
       if (!aContext || !aContext.usePrivateBrowsing) {
         this._notifyPrefRemoved(groupNames[i], aName);
       }
     }
   },
   getPrefs: function ContentPrefService_getPrefs(aGroup, aContext) {
     warnDeprecated();
     var group = this._parseGroupParam(aGroup);
     if (aContext && aContext.usePrivateBrowsing) {
         let prefs = Cc["@mozilla.org/hash-property-bag;1"].
                     createInstance(Ci.nsIWritablePropertyBag);
         for (let [sgroup, sname, sval] in this._privModeStorage) {
           if (sgroup === group)
             prefs.setProperty(sname, sval);
         }
         return prefs;
     }
     if (group == null)
       return this._selectGlobalPrefs();
     return this._selectPrefs(group);
   },
   getPrefsByName: function ContentPrefService_getPrefsByName(aName, aContext) {
     warnDeprecated();
     if (!aName)
       throw Components.Exception("aName cannot be null or an empty string",
                                  Cr.NS_ERROR_ILLEGAL_VALUE);
     if (aContext && aContext.usePrivateBrowsing) {
       let prefs = Cc["@mozilla.org/hash-property-bag;1"].
                   createInstance(Ci.nsIWritablePropertyBag);
       for (let [sgroup, sname, sval] in this._privModeStorage) {
         if (sname === aName)
           prefs.setProperty(sgroup, sval);
       }
       return prefs;
     }
     return this._selectPrefsByName(aName);
   },
   // A hash of arrays of observers, indexed by setting name.
   _observers: {},
   // An array of generic observers, which observe all settings.
   _genericObservers: [],
   addObserver: function ContentPrefService_addObserver(aName, aObserver) {
     warnDeprecated();
     this._addObserver.apply(this, arguments);
   },
   _addObserver: function ContentPrefService__addObserver(aName, aObserver) {
     var observers;
     if (aName) {
       if (!this._observers[aName])
         this._observers[aName] = [];
       observers = this._observers[aName];
     }
     else
       observers = this._genericObservers;
     if (observers.indexOf(aObserver) == -1)
       observers.push(aObserver);
   },
   removeObserver: function ContentPrefService_removeObserver(aName, aObserver) {
     warnDeprecated();
     this._removeObserver.apply(this, arguments);
   },
   _removeObserver: function ContentPrefService__removeObserver(aName, aObserver) {
     var observers;
     if (aName) {
       if (!this._observers[aName])
         return;
       observers = this._observers[aName];
     }
     else
       observers = this._genericObservers;
     if (observers.indexOf(aObserver) != -1)
       observers.splice(observers.indexOf(aObserver), 1);
   },
   /**
    * Construct a list of observers to notify about a change to some setting,
    * putting setting-specific observers before before generic ones, so observers
    * that initialize individual settings (like the page style controller)
    * execute before observers that display multiple settings and depend on them
    * being initialized first (like the content prefs sidebar).
    */
   _getObservers: function ContentPrefService__getObservers(aName) {
     var observers = [];
     if (aName && this._observers[aName])
       observers = observers.concat(this._observers[aName]);
     observers = observers.concat(this._genericObservers);
     return observers;
   },
   /**
    * Notify all observers about the removal of a preference.
    */
   _notifyPrefRemoved: function ContentPrefService__notifyPrefRemoved(aGroup, aName) {
     for each (var observer in this._getObservers(aName)) {
       try {
         observer.onContentPrefRemoved(aGroup, aName);
       }
       catch(ex) {
         Cu.reportError(ex);
       }
     }
   },
   /**
    * Notify all observers about a preference change.
    */
   _notifyPrefSet: function ContentPrefService__notifyPrefSet(aGroup, aName, aValue) {
     for each (var observer in this._getObservers(aName)) {
       try {
         observer.onContentPrefSet(aGroup, aName, aValue);
       }
       catch(ex) {
         Cu.reportError(ex);
       }
     }
   },
   get grouper() {
     warnDeprecated();
     return this._grouper;
   },
   __grouper: null,
   get _grouper() {
     if (!this.__grouper)
       this.__grouper = Cc["@mozilla.org/content-pref/hostname-grouper;1"].
                        getService(Ci.nsIContentURIGrouper);
     return this.__grouper;
   },
   get DBConnection() {
     warnDeprecated();
     return this._dbConnection;
   },
   //**************************************************************************//
   // Data Retrieval & Modification
   __stmtSelectPref: null,
   get _stmtSelectPref() {
     if (!this.__stmtSelectPref)
       this.__stmtSelectPref = this._dbCreateStatement(
         "SELECT prefs.value AS value " +
         "FROM prefs " +
         "JOIN groups ON prefs.groupID = groups.id " +
         "JOIN settings ON prefs.settingID = settings.id " +
         "WHERE groups.name = :group " +
         "AND settings.name = :setting"
       );
     return this.__stmtSelectPref;
   },
   _scheduleCallback: function(func) {
     let tm = Cc["@mozilla.org/thread-manager;1"].getService(Ci.nsIThreadManager);
     tm.mainThread.dispatch(func, Ci.nsIThread.DISPATCH_NORMAL);
   },
   _selectPref: function ContentPrefService__selectPref(aGroup, aSetting, aCallback) {
     let value = undefined;
     if (this._cache.has(aGroup, aSetting)) {
       value = this._cache.get(aGroup, aSetting);
       if (aCallback) {
         this._scheduleCallback(function(){aCallback.onResult(value);});
         return;
       }
       return value;
     }
     try {
       this._stmtSelectPref.params.group = aGroup;
       this._stmtSelectPref.params.setting = aSetting;
       if (aCallback) {
         let cache = this._cache;
         new AsyncStatement(this._stmtSelectPref).execute({onResult: function(aResult) {
           cache.set(aGroup, aSetting, aResult);
           aCallback.onResult(aResult);
         }});
       }
       else {
         if (this._stmtSelectPref.executeStep()) {
           value = this._stmtSelectPref.row["value"];
         }
         this._cache.set(aGroup, aSetting, value);
       }
     }
     finally {
       this._stmtSelectPref.reset();
     }
     return value;
   },
   __stmtSelectGlobalPref: null,
   get _stmtSelectGlobalPref() {
     if (!this.__stmtSelectGlobalPref)
       this.__stmtSelectGlobalPref = this._dbCreateStatement(
         "SELECT prefs.value AS value " +
         "FROM prefs " +
         "JOIN settings ON prefs.settingID = settings.id " +
         "WHERE prefs.groupID IS NULL " +
         "AND settings.name = :name"
       );
     return this.__stmtSelectGlobalPref;
   },
   _selectGlobalPref: function ContentPrefService__selectGlobalPref(aName, aCallback) {
     let value = undefined;
     if (this._cache.has(null, aName)) {
       value = this._cache.get(null, aName);
       if (aCallback) {
         this._scheduleCallback(function(){aCallback.onResult(value);});
         return;
       }
       return value;
     }
     try {
       this._stmtSelectGlobalPref.params.name = aName;
       if (aCallback) {
         let cache = this._cache;
         new AsyncStatement(this._stmtSelectGlobalPref).execute({onResult: function(aResult) {
           cache.set(null, aName, aResult);
           aCallback.onResult(aResult);
         }});
       }
       else {
         if (this._stmtSelectGlobalPref.executeStep()) {
           value = this._stmtSelectGlobalPref.row["value"];
         }
         this._cache.set(null, aName, value);
       }
     }
     finally {
       this._stmtSelectGlobalPref.reset();
     }
     return value;
   },
   __stmtSelectGroupID: null,
   get _stmtSelectGroupID() {
     if (!this.__stmtSelectGroupID)
       this.__stmtSelectGroupID = this._dbCreateStatement(
         "SELECT groups.id AS id " +
         "FROM groups " +
         "WHERE groups.name = :name "
       );
     return this.__stmtSelectGroupID;
   },
   _selectGroupID: function ContentPrefService__selectGroupID(aName) {
     var id;
     try {
       this._stmtSelectGroupID.params.name = aName;
       if (this._stmtSelectGroupID.executeStep())
         id = this._stmtSelectGroupID.row["id"];
     }
     finally {
       this._stmtSelectGroupID.reset();
     }
     return id;
   },
   __stmtInsertGroup: null,
   get _stmtInsertGroup() {
     if (!this.__stmtInsertGroup)
       this.__stmtInsertGroup = this._dbCreateStatement(
         "INSERT INTO groups (name) VALUES (:name)"
       );
     return this.__stmtInsertGroup;
   },
   _insertGroup: function ContentPrefService__insertGroup(aName) {
     this._stmtInsertGroup.params.name = aName;
     this._stmtInsertGroup.execute();
     return this._dbConnection.lastInsertRowID;
   },
   __stmtSelectSettingID: null,
   get _stmtSelectSettingID() {
     if (!this.__stmtSelectSettingID)
       this.__stmtSelectSettingID = this._dbCreateStatement(
         "SELECT id FROM settings WHERE name = :name"
       );
     return this.__stmtSelectSettingID;
   },
   _selectSettingID: function ContentPrefService__selectSettingID(aName) {
     var id;
     try {
       this._stmtSelectSettingID.params.name = aName;
       if (this._stmtSelectSettingID.executeStep())
         id = this._stmtSelectSettingID.row["id"];
     }
     finally {
       this._stmtSelectSettingID.reset();
     }
     return id;
   },
   __stmtInsertSetting: null,
   get _stmtInsertSetting() {
     if (!this.__stmtInsertSetting)
       this.__stmtInsertSetting = this._dbCreateStatement(
         "INSERT INTO settings (name) VALUES (:name)"
       );
     return this.__stmtInsertSetting;
   },
   _insertSetting: function ContentPrefService__insertSetting(aName) {
     this._stmtInsertSetting.params.name = aName;
     this._stmtInsertSetting.execute();
     return this._dbConnection.lastInsertRowID;
   },
   __stmtSelectPrefID: null,
   get _stmtSelectPrefID() {
     if (!this.__stmtSelectPrefID)
       this.__stmtSelectPrefID = this._dbCreateStatement(
         "SELECT id FROM prefs WHERE groupID = :groupID AND settingID = :settingID"
       );
     return this.__stmtSelectPrefID;
   },
   _selectPrefID: function ContentPrefService__selectPrefID(aGroupID, aSettingID) {
     var id;
     try {
       this._stmtSelectPrefID.params.groupID = aGroupID;
       this._stmtSelectPrefID.params.settingID = aSettingID;
       if (this._stmtSelectPrefID.executeStep())
         id = this._stmtSelectPrefID.row["id"];
     }
     finally {
       this._stmtSelectPrefID.reset();
     }
     return id;
   },
   __stmtSelectGlobalPrefID: null,
   get _stmtSelectGlobalPrefID() {
     if (!this.__stmtSelectGlobalPrefID)
       this.__stmtSelectGlobalPrefID = this._dbCreateStatement(
         "SELECT id FROM prefs WHERE groupID IS NULL AND settingID = :settingID"
       );
     return this.__stmtSelectGlobalPrefID;
   },
   _selectGlobalPrefID: function ContentPrefService__selectGlobalPrefID(aSettingID) {
     var id;
     try {
       this._stmtSelectGlobalPrefID.params.settingID = aSettingID;
       if (this._stmtSelectGlobalPrefID.executeStep())
         id = this._stmtSelectGlobalPrefID.row["id"];
     }
     finally {
       this._stmtSelectGlobalPrefID.reset();
     }
     return id;
   },
   __stmtInsertPref: null,
   get _stmtInsertPref() {
     if (!this.__stmtInsertPref)
       this.__stmtInsertPref = this._dbCreateStatement(
         "INSERT INTO prefs (groupID, settingID, value) " +
         "VALUES (:groupID, :settingID, :value)"
       );
     return this.__stmtInsertPref;
   },
   _insertPref: function ContentPrefService__insertPref(aGroupID, aSettingID, aValue) {
     this._stmtInsertPref.params.groupID = aGroupID;
     this._stmtInsertPref.params.settingID = aSettingID;
     this._stmtInsertPref.params.value = aValue;
     this._stmtInsertPref.execute();
     return this._dbConnection.lastInsertRowID;
   },
   __stmtUpdatePref: null,
   get _stmtUpdatePref() {
     if (!this.__stmtUpdatePref)
       this.__stmtUpdatePref = this._dbCreateStatement(
         "UPDATE prefs SET value = :value WHERE id = :id"
       );
     return this.__stmtUpdatePref;
   },
   _updatePref: function ContentPrefService__updatePref(aPrefID, aValue) {
     this._stmtUpdatePref.params.id = aPrefID;
     this._stmtUpdatePref.params.value = aValue;
     this._stmtUpdatePref.execute();
   },
   __stmtDeletePref: null,
   get _stmtDeletePref() {
     if (!this.__stmtDeletePref)
       this.__stmtDeletePref = this._dbCreateStatement(
         "DELETE FROM prefs WHERE id = :id"
       );
     return this.__stmtDeletePref;
   },
   _deletePref: function ContentPrefService__deletePref(aPrefID) {
     this._stmtDeletePref.params.id = aPrefID;
     this._stmtDeletePref.execute();
   },
   __stmtDeleteSettingIfUnused: null,
   get _stmtDeleteSettingIfUnused() {
     if (!this.__stmtDeleteSettingIfUnused)
       this.__stmtDeleteSettingIfUnused = this._dbCreateStatement(
         "DELETE FROM settings WHERE id = :id " +
         "AND id NOT IN (SELECT DISTINCT settingID FROM prefs)"
       );
     return this.__stmtDeleteSettingIfUnused;
   },
   _deleteSettingIfUnused: function ContentPrefService__deleteSettingIfUnused(aSettingID) {
     this._stmtDeleteSettingIfUnused.params.id = aSettingID;
     this._stmtDeleteSettingIfUnused.execute();
   },
   __stmtDeleteGroupIfUnused: null,
   get _stmtDeleteGroupIfUnused() {
     if (!this.__stmtDeleteGroupIfUnused)
       this.__stmtDeleteGroupIfUnused = this._dbCreateStatement(
         "DELETE FROM groups WHERE id = :id " +
         "AND id NOT IN (SELECT DISTINCT groupID FROM prefs)"
       );
     return this.__stmtDeleteGroupIfUnused;
   },
   _deleteGroupIfUnused: function ContentPrefService__deleteGroupIfUnused(aGroupID) {
     this._stmtDeleteGroupIfUnused.params.id = aGroupID;
     this._stmtDeleteGroupIfUnused.execute();
   },
   __stmtSelectPrefs: null,
   get _stmtSelectPrefs() {
     if (!this.__stmtSelectPrefs)
       this.__stmtSelectPrefs = this._dbCreateStatement(
         "SELECT settings.name AS name, prefs.value AS value " +
         "FROM prefs " +
         "JOIN groups ON prefs.groupID = groups.id " +
         "JOIN settings ON prefs.settingID = settings.id " +
         "WHERE groups.name = :group "
       );
     return this.__stmtSelectPrefs;
   },
   _selectPrefs: function ContentPrefService__selectPrefs(aGroup) {
     var prefs = Cc["@mozilla.org/hash-property-bag;1"].
                 createInstance(Ci.nsIWritablePropertyBag);
     try {
       this._stmtSelectPrefs.params.group = aGroup;
       while (this._stmtSelectPrefs.executeStep())
         prefs.setProperty(this._stmtSelectPrefs.row["name"],
                           this._stmtSelectPrefs.row["value"]);
     }
     finally {
       this._stmtSelectPrefs.reset();
     }
     return prefs;
   },
   __stmtSelectGlobalPrefs: null,
   get _stmtSelectGlobalPrefs() {
     if (!this.__stmtSelectGlobalPrefs)
       this.__stmtSelectGlobalPrefs = this._dbCreateStatement(
         "SELECT settings.name AS name, prefs.value AS value " +
         "FROM prefs " +
         "JOIN settings ON prefs.settingID = settings.id " +
         "WHERE prefs.groupID IS NULL"
       );
     return this.__stmtSelectGlobalPrefs;
   },
   _selectGlobalPrefs: function ContentPrefService__selectGlobalPrefs() {
     var prefs = Cc["@mozilla.org/hash-property-bag;1"].
                 createInstance(Ci.nsIWritablePropertyBag);
     try {
       while (this._stmtSelectGlobalPrefs.executeStep())
         prefs.setProperty(this._stmtSelectGlobalPrefs.row["name"],
                           this._stmtSelectGlobalPrefs.row["value"]);
     }
     finally {
       this._stmtSelectGlobalPrefs.reset();
     }
     return prefs;
   },
   __stmtSelectPrefsByName: null,
   get _stmtSelectPrefsByName() {
     if (!this.__stmtSelectPrefsByName)
       this.__stmtSelectPrefsByName = this._dbCreateStatement(
         "SELECT groups.name AS groupName, prefs.value AS value " +
         "FROM prefs " +
         "JOIN groups ON prefs.groupID = groups.id " +
         "JOIN settings ON prefs.settingID = settings.id " +
         "WHERE settings.name = :setting "
       );
     return this.__stmtSelectPrefsByName;
   },
   _selectPrefsByName: function ContentPrefService__selectPrefsByName(aName) {
     var prefs = Cc["@mozilla.org/hash-property-bag;1"].
                 createInstance(Ci.nsIWritablePropertyBag);
     try {
       this._stmtSelectPrefsByName.params.setting = aName;
       while (this._stmtSelectPrefsByName.executeStep())
         prefs.setProperty(this._stmtSelectPrefsByName.row["groupName"],
                           this._stmtSelectPrefsByName.row["value"]);
     }
     finally {
       this._stmtSelectPrefsByName.reset();
     }
     var global = this._selectGlobalPref(aName);
     if (typeof global != "undefined") {
       prefs.setProperty(null, global);
     }
     return prefs;
   },
   //**************************************************************************//
   // Database Creation & Access
   _dbVersion: 3,
   _dbSchema: {
     tables: {
       groups:     "id           INTEGER PRIMARY KEY, \
                    name         TEXT NOT NULL",
       settings:   "id           INTEGER PRIMARY KEY, \
                    name         TEXT NOT NULL",
       prefs:      "id           INTEGER PRIMARY KEY, \
                    groupID      INTEGER REFERENCES groups(id), \
                    settingID    INTEGER NOT NULL REFERENCES settings(id), \
                    value        BLOB"
     },
     indices: {
       groups_idx: {
         table: "groups",
         columns: ["name"]
       },
       settings_idx: {
         table: "settings",
         columns: ["name"]
       },
       prefs_idx: {
         table: "prefs",
         columns: ["groupID", "settingID"]
       }
     }
   },
   _dbConnection: null,
   _dbCreateStatement: function ContentPrefService__dbCreateStatement(aSQLString) {
     try {
       var statement = this._dbConnection.createStatement(aSQLString);
     }
     catch(ex) {
       Cu.reportError("error creating statement " + aSQLString + ": " +
                      this._dbConnection.lastError + " - " +
                      this._dbConnection.lastErrorString);
       throw ex;
     }
     return statement;
   },
   // _dbInit and the methods it calls (_dbCreate, _dbMigrate, and version-
   // specific migration methods) must be careful not to call any method
   // of the service that assumes the database connection has already been
   // initialized, since it won't be initialized until at the end of _dbInit.
   _dbInit: function ContentPrefService__dbInit() {
     var dirService = Cc["@mozilla.org/file/directory_service;1"].
                      getService(Ci.nsIProperties);
     var dbFile = dirService.get("ProfD", Ci.nsIFile);
     dbFile.append("content-prefs.sqlite");
     var dbService = Cc["@mozilla.org/storage/service;1"].
                     getService(Ci.mozIStorageService);
     var dbConnection;
     if (true || !dbFile.exists())
       dbConnection = this._dbCreate(dbService, dbFile);
     else {
       try {
         dbConnection = dbService.openDatabase(dbFile);
       }
       // If the connection isn't ready after we open the database, that means
       // the database has been corrupted, so we back it up and then recreate it.
       catch (e if e.result == Cr.NS_ERROR_FILE_CORRUPTED) {
         dbConnection = this._dbBackUpAndRecreate(dbService, dbFile,
                                                  dbConnection);
       }
       // Get the version of the schema in the file.
       var version = dbConnection.schemaVersion;
       // Try to migrate the schema in the database to the current schema used by
       // the service.  If migration fails, back up the database and recreate it.
       if (version != this._dbVersion) {
         try {
           this._dbMigrate(dbConnection, version, this._dbVersion);
         }
         catch(ex) {
           Cu.reportError("error migrating DB: " + ex + "; backing up and recreating");
           dbConnection = this._dbBackUpAndRecreate(dbService, dbFile, dbConnection);
         }
       }
     }
     // Turn off disk synchronization checking to reduce disk churn and speed up
     // operations when prefs are changed rapidly (such as when a user repeatedly
     // changes the value of the browser zoom setting for a site).
     //
     // Note: this could cause database corruption if the OS crashes or machine
     // loses power before the data gets written to disk, but this is considered
     // a reasonable risk for the not-so-critical data stored in this database.
     //
     // If you really don't want to take this risk, however, just set the
     // toolkit.storage.synchronous pref to 1 (NORMAL synchronization) or 2
     // (FULL synchronization), in which case mozStorageConnection::Initialize
     // will use that value, and we won't override it here.
     if (!this._prefSvc.prefHasUserValue("toolkit.storage.synchronous"))
       dbConnection.executeSimpleSQL("PRAGMA synchronous = OFF");
     this._dbConnection = dbConnection;
   },
   _dbCreate: function ContentPrefService__dbCreate(aDBService, aDBFile) {
     var dbConnection = aDBService.openSpecialDatabase("memory");
     try {
       this._dbCreateSchema(dbConnection);
       dbConnection.schemaVersion = this._dbVersion;
     }
     catch(ex) {
       // If we failed to create the database (perhaps because the disk ran out
       // of space), then remove the database file so we don't leave it in some
       // half-created state from which we won't know how to recover.
       dbConnection.close();
       aDBFile.remove(false);
       throw ex;
     }
     return dbConnection;
   },
   _dbCreateSchema: function ContentPrefService__dbCreateSchema(aDBConnection) {
     this._dbCreateTables(aDBConnection);
     this._dbCreateIndices(aDBConnection);
   },
   _dbCreateTables: function ContentPrefService__dbCreateTables(aDBConnection) {
     for (let name in this._dbSchema.tables)
       aDBConnection.createTable(name, this._dbSchema.tables[name]);
   },
   _dbCreateIndices: function ContentPrefService__dbCreateIndices(aDBConnection) {
     for (let name in this._dbSchema.indices) {
       let index = this._dbSchema.indices[name];
       let statement = "CREATE INDEX IF NOT EXISTS " + name + " ON " + index.table +
                       "(" + index.columns.join(", ") + ")";
       aDBConnection.executeSimpleSQL(statement);
     }
   },
   _dbBackUpAndRecreate: function ContentPrefService__dbBackUpAndRecreate(aDBService,
                                                                          aDBFile,
                                                                          aDBConnection) {
     aDBService.backupDatabaseFile(aDBFile, "content-prefs.sqlite.corrupt");
     // Close the database, ignoring the "already closed" exception, if any.
     // It'll be open if we're here because of a migration failure but closed
     // if we're here because of database corruption.
     try { aDBConnection.close() } catch(ex) {}
     aDBFile.remove(false);
     let dbConnection = this._dbCreate(aDBService, aDBFile);
     return dbConnection;
   },
   _dbMigrate: function ContentPrefService__dbMigrate(aDBConnection, aOldVersion, aNewVersion) {
     if (this["_dbMigrate" + aOldVersion + "To" + aNewVersion]) {
       aDBConnection.beginTransaction();
       try {
         this["_dbMigrate" + aOldVersion + "To" + aNewVersion](aDBConnection);
         aDBConnection.schemaVersion = aNewVersion;
         aDBConnection.commitTransaction();
       }
       catch(ex) {
         aDBConnection.rollbackTransaction();
         throw ex;
       }
     }
     else
       throw("no migrator function from version " + aOldVersion +
             " to version " + aNewVersion);
   },
   /**
    * If the schema version is 0, that means it was never set, which means
    * the database was somehow created without the schema being applied, perhaps
    * because the system ran out of disk space (although we check for this
    * in _createDB) or because some other code created the database file without
    * applying the schema.  In any case, recover by simply reapplying the schema.
    */
   _dbMigrate0To3: function ContentPrefService___dbMigrate0To3(aDBConnection) {
     this._dbCreateSchema(aDBConnection);
   },
   _dbMigrate1To3: function ContentPrefService___dbMigrate1To3(aDBConnection) {
     aDBConnection.executeSimpleSQL("ALTER TABLE groups RENAME TO groupsOld");
     aDBConnection.createTable("groups", this._dbSchema.tables.groups);
     aDBConnection.executeSimpleSQL(
       "INSERT INTO groups (id, name) " +
       "SELECT id, name FROM groupsOld"
     );
     aDBConnection.executeSimpleSQL("DROP TABLE groupers");
     aDBConnection.executeSimpleSQL("DROP TABLE groupsOld");
     this._dbCreateIndices(aDBConnection);
   },
   _dbMigrate2To3: function ContentPrefService__dbMigrate2To3(aDBConnection) {
     this._dbCreateIndices(aDBConnection);
   },
   _parseGroupParam: function ContentPrefService__parseGroupParam(aGroup) {
     if (aGroup == null)
       return null;
     if (aGroup.constructor.name == "String")
       return aGroup.toString();
     if (aGroup instanceof Ci.nsIURI)
       return this.grouper.group(aGroup);
     throw Components.Exception("aGroup is not a string, nsIURI or null",
                                Cr.NS_ERROR_ILLEGAL_VALUE);
   },
 };
 function warnDeprecated() {
   let Deprecated = Cu.import("resource://gre/modules/Deprecated.jsm", {}).Deprecated;
   Deprecated.warning("nsIContentPrefService is deprecated. Please use nsIContentPrefService2 instead.",
                      "https://developer.mozilla.org/en-US/docs/XPCOM_Interface_Reference/nsIContentPrefService2",
                      Components.stack.caller);
 }
 function HostnameGrouper() {}
 HostnameGrouper.prototype = {
   //**************************************************************************//
   // XPCOM Plumbing
   classID:          Components.ID("{8df290ae-dcaa-4c11-98a5-2429a4dc97bb}"),
   QueryInterface:   XPCOMUtils.generateQI([Ci.nsIContentURIGrouper]),
   //**************************************************************************//
   // nsIContentURIGrouper
   group: function HostnameGrouper_group(aURI) {
     var group;
     try {
       // Accessing the host property of the URI will throw an exception
       // if the URI is of a type that doesn't have a host property.
       // Otherwise, we manually throw an exception if the host is empty,
       // since the effect is the same (we can't derive a group from it).
       group = aURI.host;
       if (!group)
         throw("can't derive group from host; no host in URI");
     }
     catch(ex) {
       // If we don't have a host, then use the entire URI (minus the query,
       // reference, and hash, if possible) as the group.  This means that URIs
       // like about:mozilla and about:blank will be considered separate groups,
       // but at least they'll be grouped somehow.
       // This also means that each individual file: URL will be considered
       // its own group.  This seems suboptimal, but so does treating the entire
       // file: URL space as a single group (especially if folks start setting
       // group-specific capabilities prefs).
       // XXX Is there something better we can do here?
       try {
         var url = aURI.QueryInterface(Ci.nsIURL);
         group = aURI.prePath + url.filePath;
       }
       catch(ex) {
         group = aURI.spec;
       }
     }
     return group;
   }
 };
 function AsyncStatement(aStatement) {
   this.stmt = aStatement;
 }
 AsyncStatement.prototype = {
   execute: function AsyncStmt_execute(aCallback) {
     let stmt = this.stmt;
     stmt.executeAsync({
       _callback: aCallback,
       _hadResult: false,
       handleResult: function(aResult) {
         this._hadResult = true;
         if (this._callback) {
           let row = aResult.getNextRow();
           this._callback.onResult(row.getResultByName("value"));
         }
       },
       handleCompletion: function(aReason) {
         if (!this._hadResult && this._callback &&
             aReason == Ci.mozIStorageStatementCallback.REASON_FINISHED)
           this._callback.onResult(undefined);
       },
       handleError: function(aError) {}
     });
   }
 };
 //****************************************************************************//
 // XPCOM Plumbing
 var components = [ContentPrefService, HostnameGrouper];
 this.NSGetFactory = XPCOMUtils.generateNSGetFactory(components);