Refactoring AutocompleteActionPredictor Database.

chrome/browser/predictors/autocomplete_action_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_AUTOCOMPLETE_ACTION_PREDICTOR_DATABASE_H_
-#define CHROME_BROWSER_PREDICTORS_AUTOCOMPLETE_ACTION_PREDICTOR_DATABASE_H_
-#pragma once
-
-#include <ostream>
-#include <string>
-#include <vector>
-
-#include "base/file_path.h"
-#include "base/gtest_prod_util.h"
-#include "base/memory/ref_counted.h"
-#include "base/string16.h"
-#include "base/synchronization/cancellation_flag.h"
-#include "googleurl/src/gurl.h"
-#include "sql/connection.h"
-
-class Profile;
-
-// This manages the autocomplete action predictor table within the SQLite
-// database passed in to the constructor. It expects the following scheme:
-//
-// network_action_predictor
-//   id                 A unique id.
-//   user_text          What the user typed.
-//   url                The URL of the entry.
-//   number_of_hits     Number of times the entry was shown to the user and
-//                      selected.
-//   number_of_misses   Number of times the entry was shown to the user but not
-//                      selected.
-//
-// Ref-counted as it is created and destroyed on a different thread to the DB
-// thread that is required for all methods performing database access.
-class AutocompleteActionPredictorDatabase
-    : public base::RefCountedThreadSafe<AutocompleteActionPredictorDatabase> {
- public:
-  struct Row {
-    // TODO(dominich): Make this 64-bit integer as an optimization. This
-    // requires some investigation into how to make sure the id is unique for
-    // each user_text/url pair.
-    // http://crbug.com/102020
-    typedef std::string Id;
-
-    Row();
-
-    // Only used by unit tests.
-    Row(const Id& id,
-        const string16& user_text,
-        const GURL& url,
-        int number_of_hits,
-        int number_of_misses);
-
-    Id id;
-    string16 user_text;
-    GURL url;
-    int number_of_hits;
-    int number_of_misses;
-  };
-
-  explicit AutocompleteActionPredictorDatabase(Profile* profile);
-
-  // Opens the database file from the profile path. Separated from the
-  // constructor to ease construction/destruction of this object on one thread
-  // but database access on the DB thread.
-  void Initialize();
-
-  void GetRow(const Row::Id& id, Row* row);
-  void GetAllRows(std::vector<Row>* row_buffer);
-
-  void AddRow(const Row& row);
-  void UpdateRow(const Row& row);
-  void DeleteRow(const Row::Id& id);
-  void DeleteRows(const std::vector<Row::Id>& id_list);
-  void DeleteAllRows();
-
-  // For batching database operations.
-  void BeginTransaction();
-  void CommitTransaction();
-
-  void OnPredictorDestroyed();
-
- private:
-  friend class AutocompleteActionPredictorDatabaseTest;
-  friend class base::RefCountedThreadSafe<AutocompleteActionPredictorDatabase>;
-  virtual ~AutocompleteActionPredictorDatabase();
-
-  void CreateTable();
-
-  // TODO(dominich): Consider adding this table to one of the history databases.
-  // In memory is currently used, but adding to the on-disk visits database
-  // would allow DeleteOldEntries to be cheaper through use of a join.
-  FilePath db_path_;
-  sql::Connection db_;
-
-  // Set when the AutocompleteActionPredictor is destroyed so we can cancel any
-  // posted database requests.
-  base::CancellationFlag canceled_;
-
-  DISALLOW_COPY_AND_ASSIGN(AutocompleteActionPredictorDatabase);
-};
-
-#endif  // CHROME_BROWSER_PREDICTORS_AUTOCOMPLETE_ACTION_PREDICTOR_DATABASE_H_