Add tracking support to FormsEngine. Bug #435319, r=thunder

services/sync/modules/engines.js

@@ -1085,6 +1085,13 @@ FormEngine.prototype = {
     if (!this.__store)
       this.__store = new FormStore();
     return this.__store;
+  },
+  
+  __tracker: null,
+  get _tracker() {
+    if (!this.__tracker)
+      this.__tracker = new FormsTracker();
+    return this.__tracker;
   }
 };
 FormEngine.prototype.__proto__ = new Engine();

services/sync/modules/trackers.js

@@ -34,7 +34,8 @@
  *
  * ***** END LICENSE BLOCK ***** */
 
-const EXPORTED_SYMBOLS = ['Tracker', 'BookmarksTracker', 'HistoryTracker'];
+const EXPORTED_SYMBOLS = ['Tracker', 'BookmarksTracker', 'HistoryTracker',
+                          'FormsTracker'];
 
 const Cc = Components.classes;
 const Ci = Components.interfaces;
@@ -186,3 +187,72 @@ Function.prototype.async = Async.sugar;
     }
   }
   HistoryTracker.prototype.__proto__ = new Tracker();
+
+  function FormsTracker() {
+    this._init();
+  }
+  FormsTracker.prototype = {
+    _logName: "FormsTracker",
+
+    __formDB: null,
+    get _formDB() {
+      if (!this.__formDB) {
+        var file = Cc["@mozilla.org/file/directory_service;1"].
+        getService(Ci.nsIProperties).
+        get("ProfD", Ci.nsIFile);
+        file.append("formhistory.sqlite");
+        var stor = Cc["@mozilla.org/storage/service;1"].
+        getService(Ci.mozIStorageService);
+        this.__formDB = stor.openDatabase(file);
+      }
+
+      return this.__formDB;
+    }
+
+    /* nsIFormSubmitObserver is not available in JS.
+    * To calculate scores, we instead just count the changes in
+    * the database since the last time we were asked.
+    *
+    * FIXME!: Buggy, because changes in a row doesn't result in
+    * an increment of our score. A possible fix is to do a
+    * SELECT for each fieldname and compare those instead of the
+    * whole row count.
+    *
+    * Each change is worth 2 points. At some point, we may
+    * want to differentiate between search-history rows and other
+    * form items, and assign different scores.
+    */
+    _rowCount: 0,
+    get score() {
+      var stmnt = this._formDB.createStatement("SELECT COUNT(fieldname) FROM moz_formhistory");
+      stmnt.executeStep();
+      var count = stmnt.getInt32(0);
+      stmnt.reset();
+
+      this._score = abs(this._rowCount - count) * 2;
+
+      if (this._score >= 100)
+        return 100;
+      else
+        return this._score;
+    },
+
+    resetScore: function FormsTracker_resetScore() {
+      var stmnt = this._formDB.createStatement("SELECT COUNT(fieldname) FROM moz_formhistory");
+      stmnt.executeStep();
+      this._rowCount = stmnt.getInt32(0);
+      stmnt.reset();
+
+      super.resetScore();
+    },
+    
+    _init: function FormsTracker__init() {
+      super._init();
+
+      var stmnt = this._formDB.createStatement("SELECT COUNT(fieldname) FROM moz_formhistory");
+      stmnt.executeStep();
+      this._rowCount = stmnt.getInt32(0);
+      stmnt.reset();
+    }
+  }
+  FormsTracker.prototype.__proto__ = new Tracker();