chrome/browser/predictors componentization part-1

chrome/browser/predictors/predictor_database.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_PREDICTORS_PREDICTOR_DATABASE_H_
 #define CHROME_BROWSER_PREDICTORS_PREDICTOR_DATABASE_H_
 
+#include "base/file_path.h"
 #include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
 #include "chrome/browser/profiles/profile_keyed_service.h"
 
-class Profile;
-
 namespace sql {
 class Connection;
 }
 
 namespace predictors {
 
 class AutocompleteActionPredictorTable;
 class PredictorDatabaseInternal;
 class ResourcePrefetchPredictorTables;
 
-class PredictorDatabase : public ProfileKeyedService {
+// Refcounted as it is created, initialized and destroyed on a different thread
+// to the DB thread that is required for all methods performing database access.
+class PredictorDatabase
+    : public base::RefCountedThreadSafe<PredictorDatabase> {
  public:
-  explicit PredictorDatabase(Profile* profile);
+  explicit PredictorDatabase(const FilePath& path,
+                             bool is_resource_prefetch_predictor_enabled);
   virtual ~PredictorDatabase();
 
   scoped_refptr<AutocompleteActionPredictorTable> autocomplete_table();
   scoped_refptr<ResourcePrefetchPredictorTables> resource_prefetch_tables();
 
+  // Cancels pending DB transactions. Should only be called on the UI thread.
+  void SetCancelled();
+
   // Used for testing.
   sql::Connection* GetDatabase();
 
  private:
-  // ProfileKeyedService
-  virtual void Shutdown() OVERRIDE;
+  friend class base::RefCountedThreadSafe<PredictorDatabase>;
 
-  scoped_refptr<PredictorDatabaseInternal> db_;
+  // Opens the database file. Separated from the constructor to ease
+  // construction/destruction of this object on one thread but database access
+  // on the DB thread.
+  void Initialize();
+  void LogDatabaseStats();  //  DB Thread.
+
+  FilePath db_path_;
+  bool is_resource_prefetch_predictor_enabled_;
+  scoped_ptr<sql::Connection> db_;
+
+  // TODO(shishir): These tables may not need to be refcounted. Maybe move them
+  // to using a WeakPtr instead.
+  scoped_refptr<AutocompleteActionPredictorTable> autocomplete_table_;
+  scoped_refptr<ResourcePrefetchPredictorTables> resource_prefetch_tables_;
 
   DISALLOW_COPY_AND_ASSIGN(PredictorDatabase);
 };
 
 }  // namespace predictors
 
 #endif  // CHROME_BROWSER_PREDICTORS_PREDICTOR_DATABASE_H_