Improve handling of preferences in Firefox

extensions/firefox/bootstrap.js

@@ -16,7 +16,7 @@
  */
 /* jshint esnext:true */
 /* globals Components, Services, dump, XPCOMUtils, PdfStreamConverter,
-           PdfRedirector, APP_SHUTDOWN */
+           PdfRedirector, APP_SHUTDOWN, DEFAULT_PREFERENCES */
 
 'use strict';
 
@@ -56,6 +56,27 @@ function log(str) {
   dump(str + '\n');
 }
 
+function initializeDefaultPreferences() {
+  Cu.import('resource://' + RESOURCE_NAME + '/default_preferences.js');
+
+  var defaultBranch = Services.prefs.getDefaultBranch(EXT_PREFIX + '.');
+  var defaultValue;
+  for (var key in DEFAULT_PREFERENCES) {
+    defaultValue = DEFAULT_PREFERENCES[key];
+    switch (typeof defaultValue) {
+      case 'boolean':
+        defaultBranch.setBoolPref(key, defaultValue);
+        break;
+      case 'number':
+        defaultBranch.setIntPref(key, defaultValue);
+        break;
+      case 'string':
+        defaultBranch.setCharPref(key, defaultValue);
+        break;
+    }
+  }
+}
+
 // Factory that registers/unregisters a constructor as a component.
 function Factory() {}
 
@@ -124,6 +145,8 @@ function startup(aData, aReason) {
     Ph.registerPlayPreviewMimeType('application/pdf', true,
       'data:application/x-moz-playpreview-pdfjs;,');
   }
+
+  initializeDefaultPreferences();
 }
 
 function shutdown(aData, aReason) {

extensions/firefox/content/PdfJs.jsm

@@ -61,6 +61,27 @@ function getIntPref(aPref, aDefaultValue) {
   }
 }
 
+function initializeDefaultPreferences() {
+  Cu.import('resource://pdf.js/default_preferences.js');
+
+  var defaultBranch = Services.prefs.getDefaultBranch(PREF_PREFIX + '.');
+  var defaultValue;
+  for (var key in DEFAULT_PREFERENCES) {
+    defaultValue = DEFAULT_PREFERENCES[key];
+    switch (typeof defaultValue) {
+      case 'boolean':
+        defaultBranch.setBoolPref(key, defaultValue);
+        break;
+      case 'number':
+        defaultBranch.setIntPref(key, defaultValue);
+        break;
+      case 'string':
+        defaultBranch.setCharPref(key, defaultValue);
+        break;
+    }
+  }
+}
+
 // Register/unregister a constructor as a factory.
 function Factory() {}
 Factory.prototype = {
@@ -104,6 +125,8 @@ let PdfJs = {
     Services.obs.addObserver(this, TOPIC_PDFJS_HANDLER_CHANGED, false);
     Services.obs.addObserver(this, TOPIC_PLUGINS_LIST_UPDATED, false);
     Services.obs.addObserver(this, TOPIC_PLUGIN_INFO_UPDATED, false);
+
+    initializeDefaultPreferences();
   },
 
   _migrate: function migrate() {

extensions/firefox/content/PdfStreamConverter.jsm

@@ -16,7 +16,7 @@
  */
 /* jshint esnext:true */
 /* globals Components, Services, XPCOMUtils, NetUtil, PrivateBrowsingUtils,
-           dump, NetworkManager, PdfJsTelemetry, DEFAULT_PREFERENCES */
+           dump, NetworkManager, PdfJsTelemetry */
 
 'use strict';
 
@@ -33,16 +33,14 @@ const PDF_CONTENT_TYPE = 'application/pdf';
 const PREF_PREFIX = 'PDFJSSCRIPT_PREF_PREFIX';
 const PDF_VIEWER_WEB_PAGE = 'resource://pdf.js/web/viewer.html';
 const MAX_DATABASE_LENGTH = 4096;
-const MAX_STRING_PREF_LENGTH = 4096;
+const MAX_NUMBER_OF_PREFS = 50;
+const MAX_STRING_PREF_LENGTH = 128;
 
 Cu.import('resource://gre/modules/XPCOMUtils.jsm');
 Cu.import('resource://gre/modules/Services.jsm');
 Cu.import('resource://gre/modules/NetUtil.jsm');
 Cu.import('resource://pdf.js/network.js');
 
-// Load the default preferences.
-Cu.import('resource://pdf.js/default_preferences.js');
-
 XPCOMUtils.defineLazyModuleGetter(this, 'PrivateBrowsingUtils',
   'resource://gre/modules/PrivateBrowsingUtils.jsm');
 
@@ -453,23 +451,20 @@ ChromeActions.prototype = {
                                    .updateControlState(result, findPrevious);
   },
   setPreferences: function(prefs) {
-    var prefValue, defaultValue, prefName, prefType, defaultType;
-
-    for (var key in DEFAULT_PREFERENCES) {
-      prefValue = prefs[key];
-      defaultValue = DEFAULT_PREFERENCES[key];
-      prefName = (PREF_PREFIX + '.' + key);
-
-      if (prefValue === undefined || prefValue === defaultValue) {
-        Services.prefs.clearUserPref(prefName);
-      } else {
-        prefType = typeof prefValue;
-        defaultType = typeof defaultValue;
-
-        if (prefType !== defaultType) {
+    var defaultBranch = Services.prefs.getDefaultBranch(PREF_PREFIX + '.');
+    var numberOfPrefs = 0;
+    var prefValue, prefName;
+    for (var key in prefs) {
+      if (++numberOfPrefs > MAX_NUMBER_OF_PREFS) {
+        log('setPreferences - Exceeded the maximum number of preferences ' +
+            'that is allowed to be set at once.');
+        break;
+      } else if (!defaultBranch.getPrefType(key)) {
         continue;
       }
-        switch (defaultType) {
+      prefValue = prefs[key];
+      prefName = (PREF_PREFIX + '.' + key);
+      switch (typeof prefValue) {
         case 'boolean':
           setBoolPref(prefName, prefValue);
           break;
@@ -477,32 +472,39 @@ ChromeActions.prototype = {
           setIntPref(prefName, prefValue);
           break;
         case 'string':
-            // Protect against adding arbitrarily long strings in about:config.
-            if (prefValue.length <= MAX_STRING_PREF_LENGTH) {
+          if (prefValue.length > MAX_STRING_PREF_LENGTH) {
+            log('setPreferences - Exceeded the maximum allowed length ' +
+                'for a string preference.');
+          } else {
             setStringPref(prefName, prefValue);
           }
           break;
       }
     }
-    }
   },
-  getPreferences: function() {
-    var currentPrefs = {};
-    var defaultValue, prefName;
-
-    for (var key in DEFAULT_PREFERENCES) {
-      defaultValue = DEFAULT_PREFERENCES[key];
+  getPreferences: function(prefs) {
+    var defaultBranch = Services.prefs.getDefaultBranch(PREF_PREFIX + '.');
+    var currentPrefs = {}, numberOfPrefs = 0;
+    var prefValue, prefName;
+    for (var key in prefs) {
+      if (++numberOfPrefs > MAX_NUMBER_OF_PREFS) {
+        log('getPreferences - Exceeded the maximum number of preferences ' +
+            'that is allowed to be fetched at once.');
+        break;
+      } else if (!defaultBranch.getPrefType(key)) {
+        continue;
+      }
+      prefValue = prefs[key];
       prefName = (PREF_PREFIX + '.' + key);
-
-      switch (typeof defaultValue) {
+      switch (typeof prefValue) {
         case 'boolean':
-          currentPrefs[key] = getBoolPref(prefName, defaultValue);
+          currentPrefs[key] = getBoolPref(prefName, prefValue);
           break;
         case 'number':
-          currentPrefs[key] = getIntPref(prefName, defaultValue);
+          currentPrefs[key] = getIntPref(prefName, prefValue);
           break;
         case 'string':
-          currentPrefs[key] = getStringPref(prefName, defaultValue);
+          currentPrefs[key] = getStringPref(prefName, prefValue);
           break;
       }
     }

web/firefoxcom.js

@@ -108,9 +108,10 @@ Preferences.prototype.writeToStorage = function(prefObj) {
   FirefoxCom.requestSync('setPreferences', prefObj);
 };
 
-Preferences.prototype.readFromStorage = function() {
+Preferences.prototype.readFromStorage = function(prefObj) {
   var readFromStoragePromise = new Promise(function (resolve) {
-    var readPrefs = JSON.parse(FirefoxCom.requestSync('getPreferences'));
+    var readPrefs = JSON.parse(FirefoxCom.requestSync('getPreferences',
+                                                      prefObj));
     resolve(readPrefs);
   });
   return readFromStoragePromise;

web/preferences.js

@@ -24,7 +24,8 @@ var Preferences = (function PreferencesClosure() {
   function Preferences() {
     this.prefs = {};
     this.isInitializedPromiseResolved = false;
-    this.initializedPromise = this.readFromStorage().then(function(prefObj) {
+    this.initializedPromise = this.readFromStorage(DEFAULT_PREFERENCES).then(
+      function(prefObj) {
         this.isInitializedPromiseResolved = true;
         if (prefObj) {
           this.prefs = prefObj;
@@ -37,7 +38,7 @@ var Preferences = (function PreferencesClosure() {
       return;
     },
 
-    readFromStorage: function Preferences_readFromStorage() {
+    readFromStorage: function Preferences_readFromStorage(prefObj) {
       var readFromStoragePromise = Promise.resolve();
       return readFromStoragePromise;
     },
@@ -45,7 +46,7 @@ var Preferences = (function PreferencesClosure() {
     reset: function Preferences_reset() {
       if (this.isInitializedPromiseResolved) {
         this.prefs = {};
-        this.writeToStorage(this.prefs);
+        this.writeToStorage(DEFAULT_PREFERENCES);
       }
     },
 
@@ -70,6 +71,12 @@ var Preferences = (function PreferencesClosure() {
                         valueType + '\", expected a \"' + defaultType + '\".');
           return;
         }
+      } else {
+        if (valueType === 'number' && (value | 0) !== value) {
+          console.error('Preferences_set: \'' + value +
+                        '\' must be an \"integer\".');
+          return;
+        }
       }
       this.prefs[name] = value;
       this.writeToStorage(this.prefs);
@@ -97,13 +104,13 @@ var Preferences = (function PreferencesClosure() {
 
 //#if B2G
 //Preferences.prototype.writeToStorage = function(prefObj) {
-//  asyncStorage.setItem('preferences', JSON.stringify(prefObj));
+//  asyncStorage.setItem('pdfjs.preferences', JSON.stringify(prefObj));
 //};
 //
-//Preferences.prototype.readFromStorage = function() {
+//Preferences.prototype.readFromStorage = function(prefObj) {
 //  var readFromStoragePromise = new Promise(function (resolve) {
-//    asyncStorage.getItem('preferences', function(prefString) {
-//      var readPrefs = JSON.parse(prefString);
+//    asyncStorage.getItem('pdfjs.preferences', function(prefStr) {
+//      var readPrefs = JSON.parse(prefStr);
 //      resolve(readPrefs);
 //    });
 //  });
@@ -114,14 +121,14 @@ var Preferences = (function PreferencesClosure() {
 //#if !(FIREFOX || MOZCENTRAL || B2G)
 Preferences.prototype.writeToStorage = function(prefObj) {
   if (isLocalStorageEnabled) {
-    localStorage.setItem('preferences', JSON.stringify(prefObj));
+    localStorage.setItem('pdfjs.preferences', JSON.stringify(prefObj));
   }
 };
 
-Preferences.prototype.readFromStorage = function() {
+Preferences.prototype.readFromStorage = function(prefObj) {
   var readFromStoragePromise = new Promise(function (resolve) {
     if (isLocalStorageEnabled) {
-      var readPrefs = JSON.parse(localStorage.getItem('preferences'));
+      var readPrefs = JSON.parse(localStorage.getItem('pdfjs.preferences'));
       resolve(readPrefs);
     }
   });