Issue 4023 - Use localforage (IndexedDB) instead of localStorage

lib/adblockplus.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2016 Eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 339 matching lines @@
 require.scopes["io"] = (function()
 {
   var exports = {};
   var keyPrefix = "file:";
 
   function fileToKey(file)
   {
     return keyPrefix + (file instanceof FakeFile ? file.path : file.spec);
   }
 
-  function loadFile(file)
+  function loadFile(file, successCallback, errorCallback)
   {
-    return new Promise(function(resolve, reject)
+    var key = fileToKey(file);
+    var entry = localStorage.getItem(key);
+    if (entry)
     {
-      var key = fileToKey(file);
-      ext.storage.get([key], function(items)
-      {
-        var entry = items[key];
-        if (!entry)
-        {
-          try
-          {
-            entry = JSON.parse(window.localStorage.getItem(key));
-          }
-          catch (err)
-          {}
-        }
-        if (entry)
-        {
-          resolve(entry);
-        }
-        else
-        {
-          reject(new Error("File doesn't exist"));
-        }
-      });
-    }.bind(this));
-  }
-  function saveFile(file, data, callback)
-  {
-    var entry = {};
-    var key = fileToKey(file);
-
-    if (typeof browser == "undefined")
-    {
-      entry[key] = {
-        lastModified: Date.now(),
-        content: data
-      };
-      ext.storage.set(entry, callback);
+      successCallback(JSON.parse(entry));

[Sebastian Noack, 2016/10/06 12:07:36]

Don't we have to respond asynchronously here (i.e. wrap it by setTimeout)?

[Oleksandr, 2016/10/06 23:28:13]

Indeed, we should. Great catch! For reference, this is discussed here:
https://codereview.adblockplus.org/29348698/diff/29348738/lib/adblockplus.js#....
I wasn't able to test the full upgrade, but a synthetic test did show that this
has to return asynchronously.

[Sebastian Noack, 2016/10/06 23:38:35]

Yes, that is what I remember, and why I brought it up here.

     }
     else
     {
-      var processedData = LZString.compressToUTF16(JSON.stringify(data));
-      ext.storage.remove(key);
-      entry[key] = {
-        lastModified: Date.now(),
-        content: processedData,
-        compressed: true
-      };
-      window.localStorage.setItem(key, JSON.stringify(entry[key]));
-      setTimeout(callback, 0);
+      entry = localforage.getItem(key, function(err, value) 

[Sebastian Noack, 2016/10/06 12:07:36]

It seems unnecessary to assign to "entry" here. It seems unused.

[Oleksandr, 2016/10/06 23:28:13]

Done.

+      {
+        if (err || !value)
+          errorCallback(new Error("File doesn't exist"));                
+        else
+          successCallback(value);
+      });
     }
-    callback();
+  }
+
+  function saveFile(file, data, callback)
+  {
+    var key = fileToKey(file);
+    var entry = {
+      lastModified: Date.now(),
+      content: data
+    };
+
+    localStorage.removeItem(key);
+    localforage.setItem(key, entry, callback);
   }
   exports.IO = {
     resolveFilePath: function(path)
     {
       return new FakeFile(path);
     },
     readFromFile: function(file, listener, callback)
     {
       function onLoaded(entry)
       {
         if ("content" in entry)
         {
-          if (entry["compressed"])
-          {
-            entry.content = JSON.parse(LZString.decompressFromUTF16(entry.content));
-          }
           for (var _loopIndex15 = 0; _loopIndex15 < entry.content.length; ++_loopIndex15)
           {
             var line = entry.content[_loopIndex15];
             listener.process(line);
           }
         }
         callback(null);
       }
-      loadFile(file).then(onLoaded, callback);
+      loadFile(file, onLoaded, callback);
     },
     writeToFile: function(file, data, callback)
     {
       saveFile(file, data, callback);
     },
     copyFile: function(fromFile, toFile, callback)
     {
       function onLoaded(entry)
       {
         saveFile(toFile, entry.content, callback);
       }
-      loadFile(file).then(onLoaded, callback);
+      loadFile(file, onLoaded, callback);
     },
     renameFile: function(fromFile, newName, callback)
     {
       function onLoaded()
       {
         ext.storage.remove(fileToKey(fromFile), function()
         {
           ext.storage.set(keyPrefix + newName, entry, callback);
         });
       }
-      loadFile(file).then(onLoaded, callback);
+      loadFile(file, onLoaded, callback);
     },
     removeFile: function(file, callback)
     {
       ext.storage.remove(fileToKey(file), callback);
     },
     statFile: function(file, callback)
     {
       function onLoaded(entry)
       {
         callback(null,
         {
           exists: true,
           lastModified: entry.lastModified
         });
       }
-      loadFile(file).then(onLoaded, callback);
+      loadFile(file, onLoaded, callback);
     }
   };
   return exports;
 })();
 require.scopes["downloader"] = (function()
 {
   var exports = {};
   var Utils = require("utils").Utils;
   var MILLIS_IN_SECOND = exports.MILLIS_IN_SECOND = 1000;
   var MILLIS_IN_MINUTE = exports.MILLIS_IN_MINUTE = 60 * MILLIS_IN_SECOND;
@@ skipping 6088 matching lines @@
     search.push("notificationDownloadCount=" + encodeURIComponent(downlCount));
     chrome.runtime.setUninstallURL(Utils.getDocLink("uninstalled") + "&" + search.join("&"));
   }
   if ("setUninstallURL" in chrome.runtime)
   {
     Prefs.untilLoaded.then(setUninstallURL);
     Prefs.on("notificationdata", setUninstallURL);
   }
   return exports;
 })();