Added ad counting functionality

lib/stats.js

Index: lib/stats.js
===================================================================
new file mode 100644
--- /dev/null
+++ b/lib/stats.js
@@ -0,0 +1,74 @@
+/*
+ * This file is part of Adblock Plus <http://adblockplus.org/>,
+ * Copyright (C) 2006-2013 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/>.
+ */
+
+/**
+ * @fileOverview Provides usage stats
+ */
+
+let {Prefs} = require("prefs");
+let {BlockingFilter} = require("filterClasses");
+let {FilterNotifier} = require("filterNotifier");
+
+/**
+ * Base class for individual stats
+ * @param {Object} stats simple object representation of stats
+ */
+let StatsObject = exports.StatsObject = function(stats)
+{
+  if (typeof stats == "undefined")
+    return;
+  
+  this.blocked = stats.blocked || this.blocked;
+}
+StatsObject.prototype = {
+  /**
+   * Number of blocked resources
+   * @type Number
+   */
+  blocked: 0
+};
+
+let total = new StatsObject(Prefs["stats_total"]);
+
+let Stats = exports.Stats = {
+  /**
+   * Total counts
+   */
+  get total()
+  {
+    return total;
+  }
+}

[Wladimir Palant, 2013/09/18 09:44:41]

The exported API here seems overly complicated for the job. If anything, that
module only needs to export a single getStats() function:

let getStats = exports.getStats = function getStats(tabId)
{
  if (tabId)
  {
    let frameData = getFrameData(tabId, 0);
    return (frameData && "blocked" in frameData ? frameData.blocked : 0);
  }
  else
    return Prefs.stats_total;
};

StatsObject and Stats objects aren't really necessary, and neither is caching
the prefs value in a local variable.

+
+FilterNotifier.addListener(function(action, item, tabId)
+{
+  if (action != "document.stats")
+    return;
+  
+  var blocked = item instanceof BlockingFilter;
+  
+  // increment counts
+  if (blocked)
+    total.blocked++;

[Wladimir Palant, 2013/09/18 09:44:41]

Prefs.stats_total++; will do here, no point caching that value.

+  
+  ChromeCompat.tabs.sendMessage(tabId, {
+    reqtype: "update-stats",
+    blocked: blocked
+  }, null);

[Wladimir Palant, 2013/09/18 09:44:41]

Simpler:

let frameData = getFrameData(tabId, 0);
if (frameData)
{
  if ("blocked" in frameData)
    frameData.blocked++;
  else
    frameData.blocked = 1;
}

+  
+  Prefs["stats_total"] = total;
+});