Issue 4023 - Use localforage (IndexedDB) instead of localStorage

lib/adblockplus.js

Index: lib/adblockplus.js
===================================================================
--- a/lib/adblockplus.js
+++ b/lib/adblockplus.js
@@ -357,60 +357,43 @@
     return keyPrefix + (file instanceof FakeFile ? file.path : file.spec);
   }
 
-  function loadFile(file)
-  {
-    return new Promise(function(resolve, reject)
-    {
-      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);
-        }
+  function loadFile(file, successCallback, errorCallback)
+  {
+    var key = fileToKey(file);
+    var entry = localStorage.getItem(key);
+    if (entry)
+    {
+      try
+      {
+        setTimeout(successCallback(JSON.parse(entry)), 0);

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

Not too important but you can call setTimout() without secomd parameter. That is
equivalent to passing 0. Not sure if it is worth catching that theoretical error
in the first place.

[Oleksandr, 2016/10/07 16:29:17]

Done. But I think it wouldn't hurt catching an error here. I stumbled across
this when I tried my synthetic test of upgrade. Who knows what can be found in
localStorage, really... Users can edit it manually too, in theory.

[kzar, 2016/10/07 17:00:00]

Wouldn't this also catch an exception thrown by the successCallback function,
resulting in both successCallback and errorCallback to be called?

[Oleksandr, 2016/10/07 17:21:06]

Yes, but I think that's expected, no?

+      }
+      catch(err) 
+      {
+        setTimeout(errorCallback(new Error("File is corrupted")), 0);
+      }
+    }
+    else
+    {
+      localforage.getItem(key, function(err, value) 
+      {
+        if (err || !value)
+          errorCallback(new Error("File doesn't exist"));                
         else
-        {
-          reject(new Error("File doesn't exist"));
-        }
+          successCallback(value);
       });
-    }.bind(this));
+    }
   }
+
   function saveFile(file, data, callback)
   {
-    var entry = {};
     var key = fileToKey(file);
+    var entry = {
+      lastModified: Date.now(),
+      content: data
+    };
 
-    if (typeof browser == "undefined")
-    {
-      entry[key] = {
-        lastModified: Date.now(),
-        content: data
-      };
-      ext.storage.set(entry, callback);
-    }
-    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);
-    }
-    callback();
+    localStorage.removeItem(key);
+    localforage.setItem(key, entry, callback);
   }
   exports.IO = {
     resolveFilePath: function(path)
@@ -423,10 +406,6 @@
       {
         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];
@@ -435,7 +414,7 @@
         }
         callback(null);
       }
-      loadFile(file).then(onLoaded, callback);
+      loadFile(file, onLoaded, callback);
     },
     writeToFile: function(file, data, callback)
     {
@@ -447,7 +426,7 @@
       {
         saveFile(toFile, entry.content, callback);
       }
-      loadFile(file).then(onLoaded, callback);
+      loadFile(file, onLoaded, callback);
     },
     renameFile: function(fromFile, newName, callback)
     {
@@ -458,7 +437,7 @@
           ext.storage.set(keyPrefix + newName, entry, callback);
         });
       }
-      loadFile(file).then(onLoaded, callback);
+      loadFile(file, onLoaded, callback);
     },
     removeFile: function(file, callback)
     {
@@ -474,7 +453,7 @@
           lastModified: entry.lastModified
         });
       }
-      loadFile(file).then(onLoaded, callback);
+      loadFile(file, onLoaded, callback);
     }
   };
   return exports;