issue #660 - Switch to version 2 of the HTTP cache API

chrome/content/ui/sidebar.js

 /*
  * This file is part of Adblock Plus <http://adblockplus.org/>,
  * Copyright (C) 2006-2014 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
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 Cu.import("resource://gre/modules/XPCOMUtils.jsm");
 
 // Main browser window
 var mainWin = parent;
 
 // The window handler currently in use
 var requestNotifier = null;
 
-var cacheSession = null;
+var cacheStorage = null;
 var noFlash = false;
 
 // Matcher for disabled filters
 var disabledMatcher = new CombinedMatcher();
 
 // Cached string values
 var docDomainThirdParty = null;
 var docDomainFirstParty = null;
 
 function init() {
@@ skipping 251 matching lines @@
       while (sourceElement.firstChild)
         sourceElement.removeChild(sourceElement.firstChild);
       for (let i = 0; i < subscriptions.length; i++)
         setMultilineContent(sourceElement, subscriptions[i].title, true);
     }
   }
 
   var showPreview = Prefs.previewimages && !("tooltip" in item);
   showPreview = showPreview && item.typeDescr == "IMAGE";
   showPreview = showPreview && (!item.filter || item.filter.disabled || item.filter instanceof WhitelistFilter);
+  E("tooltipPreviewBox").hidden = true;
   if (showPreview)
   {
-    // Check whether image is in cache (stolen from ImgLikeOpera)
-    if (!cacheSession)
+    if (!cacheStorage)
     {
-      var cacheService = Cc["@mozilla.org/network/cache-service;1"].getService(Ci.nsICacheService);
-      cacheSession = cacheService.createSession("HTTP", Ci.nsICache.STORE_ANYWHERE, true);
+      // Cache v2 API is enabled by default starting with Gecko 32
+      if (Services.vc.compare(Utils.platformVersion, "32.0") >= 0)
+      {
+        let {LoadContextInfo} = Cu.import("resource://gre/modules/LoadContextInfo.jsm", null);
+        let cacheService = Cc["@mozilla.org/netwerk/cache-storage-service;1"].getService(Ci.nsICacheStorageService);
+        cacheStorage = cacheService.diskCacheStorage(LoadContextInfo.default, true);

[Wladimir Palant, 2014/07/02 05:00:03]

Apparently, this interface was added to Services.jsm
(https://developer.mozilla.org/en-US/docs/Mozilla/JavaScript_code_modules/Serv...),
we should use it. Please import Services.jsm and use Services.cache2 here.

[saroyanm, 2014/07/02 07:03:41]

Good point.

+      }
+      else
+      {
+        let cacheService = Cc["@mozilla.org/network/cache-service;1"].getService(Ci.nsICacheService);
+        cacheStorage = cacheService.createSession("HTTP", Ci.nsICache.STORE_ANYWHERE, true);

[Wladimir Palant, 2014/07/02 05:00:03]

We should use Services.cache here.

+      }
     }
-
-    let cacheListener =
+    
+    let showTooltipPreview = function ()
     {
-       onCacheEntryAvailable: function(descriptor, accessGranted, status)
-       {
-          if (!descriptor)
-            return;
-
-          descriptor.close();
-          // Show preview here since this is asynchronous now
-          // and we have a valid descriptor
-          E("tooltipPreview").setAttribute("src", item.location);
-          E("tooltipPreviewBox").hidden = false;
-       },
-       onCacheEntryDoomed: function(status)
-       {
-       }
-    };
+      E("tooltipPreview").setAttribute("src", item.location);
+      E("tooltipPreviewBox").hidden = false;
+    }

[Wladimir Palant, 2014/07/02 05:00:03]

Missing semicolon after } here.

[saroyanm, 2014/07/02 07:03:41]

Done.

     try
     {
-      cacheSession.asyncOpenCacheEntry(item.location, Ci.nsICache.ACCESS_READ, cacheListener);
+      if (Ci.nsICacheStorage && cacheStorage instanceof Ci.nsICacheStorage)
+      {
+        cacheStorage.asyncOpenURI(Utils.makeURI(item.location), "", Ci.nsICacheStorage.OPEN_READONLY, {
+          onCacheEntryCheck: function (entry, appCache)
+          {
+            return Ci.nsICacheEntryOpenCallback.ENTRY_WANTED;
+          },
+          onCacheEntryAvailable: function (entry, isNew, appCache, status) {
+            if (!isNew)
+              showTooltipPreview();
+          }
+        });
+      }
+      else
+      {
+        cacheStorage.asyncOpenCacheEntry(item.location, Ci.nsICache.ACCESS_READ, {
+          onCacheEntryAvailable: function(descriptor, accessGranted, status)
+          {
+            if (!descriptor)
+              return;
+            descriptor.close();
+            showTooltipPreview();
+          },
+          onCacheEntryDoomed: function(status)
+          {
+          }
+        });
+      }
     }
     catch (e)
     {
       Cu.reportError(e);
     }
   }
-
-  E("tooltipPreviewBox").hidden = true;
 }
 
 const visual = {
   OTHER: true,
   IMAGE: true,
   SUBDOCUMENT: true
 }
 
 /**
  * Updates context menu before it is shown.
@@ skipping 892 matching lines @@
       return {tooltip: this.itemsDummyTooltip};
   },
 
   invalidateItem: function(item)
   {
     let row = this.data.indexOf(item);
     if (row >= 0)
       this.boxObject.invalidateRow(row);
   }
 }