Refactoring, moving and renaming the NetworkActionPredictor.

chrome/browser/autocomplete/network_action_predictor.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_AUTOCOMPLETE_NETWORK_ACTION_PREDICTOR_H_
-#define CHROME_BROWSER_AUTOCOMPLETE_NETWORK_ACTION_PREDICTOR_H_
-#pragma once
-
-#include <map>
-
-#include "base/gtest_prod_util.h"
-#include "base/memory/scoped_ptr.h"
-#include "base/memory/weak_ptr.h"
-#include "base/string16.h"
-#include "chrome/browser/autocomplete/network_action_predictor_database.h"
-#include "chrome/browser/history/history_types.h"
-#include "chrome/browser/profiles/profile_keyed_service.h"
-#include "content/public/browser/notification_observer.h"
-#include "content/public/browser/notification_registrar.h"
-#include "googleurl/src/gurl.h"
-
-struct AutocompleteLog;
-struct AutocompleteMatch;
-class AutocompleteResult;
-class HistoryService;
-class Profile;
-
-namespace history {
-class URLDatabase;
-}
-
-// This class is responsible for determining the correct predictive network
-// action to take given for a given AutocompleteMatch and entered text. it uses
-// a NetworkActionPredictorDatabase accessed asynchronously on the DB thread to
-// permanently store the data used to make predictions, and keeps local caches
-// of that data to be able to make predictions synchronously on the UI thread
-// where it lives. It can be accessed as a weak pointer so that it can safely
-// use PostTaskAndReply without fear of crashes if it is destroyed before the
-// reply triggers. This is necessary during initialization.
-class NetworkActionPredictor
-    : public ProfileKeyedService,
-      public content::NotificationObserver,
-      public base::SupportsWeakPtr<NetworkActionPredictor> {
- public:
-  enum Action {
-    ACTION_PRERENDER = 0,
-    ACTION_PRECONNECT,
-    ACTION_NONE,
-    LAST_PREDICT_ACTION = ACTION_NONE
-  };
-
-  explicit NetworkActionPredictor(Profile* profile);
-  virtual ~NetworkActionPredictor();
-
-  static void set_hit_weight(double weight) { hit_weight_ = weight; }
-  static double get_hit_weight() { return hit_weight_; }
-
-  // Registers an AutocompleteResult for a given |user_text|. This will be used
-  // when the user navigates from the Omnibox to determine early opportunities
-  // to predict their actions.
-  void RegisterTransitionalMatches(const string16& user_text,
-                                   const AutocompleteResult& result);
-
-  // Clears any transitional matches that have been registered. Called when, for
-  // example, the AutocompleteEditModel is reverted.
-  void ClearTransitionalMatches();
-
-  // Return the recommended action given |user_text|, the text the user has
-  // entered in the Omnibox, and |match|, the suggestion from Autocomplete.
-  // This method uses information from the ShortcutsBackend including how much
-  // of the matching entry the user typed, and how long it's been since the user
-  // visited the matching URL, to calculate a score between 0 and 1. This score
-  // is then mapped to an Action.
-  Action RecommendAction(const string16& user_text,
-                         const AutocompleteMatch& match) const;
-
-  // Return true if the suggestion type warrants a TCP/IP preconnection.
-  // i.e., it is now quite likely that the user will select the related domain.
-  static bool IsPreconnectable(const AutocompleteMatch& match);
-
- private:
-  friend class NetworkActionPredictorTest;
-  friend class NetworkActionPredictorDOMHandler;
-
-  struct TransitionalMatch {
-    TransitionalMatch();
-    ~TransitionalMatch();
-
-    string16 user_text;
-    std::vector<GURL> urls;
-
-    bool operator==(const string16& other_user_text) const {
-      return user_text == other_user_text;
-    }
-  };
-
-  struct DBCacheKey {
-    string16 user_text;
-    GURL url;
-
-    bool operator<(const DBCacheKey& rhs) const {
-      return (user_text != rhs.user_text) ?
-          (user_text < rhs.user_text) :  (url < rhs.url);
-    }
-
-    bool operator==(const DBCacheKey& rhs) const {
-      return (user_text == rhs.user_text) && (url == rhs.url);
-    }
-  };
-
-  struct DBCacheValue {
-    int number_of_hits;
-    int number_of_misses;
-  };
-
-  typedef std::map<DBCacheKey, DBCacheValue> DBCacheMap;
-  typedef std::map<DBCacheKey, NetworkActionPredictorDatabase::Row::Id>
-      DBIdCacheMap;
-
-  static const int kMaximumDaysToKeepEntry;
-
-  // Multiplying factor applied to the |number_of_hits| for a database entry
-  // when calculating the confidence. It is currently set by a field trial so is
-  // static. Once the field trial ends, this will be a constant value.
-  static double hit_weight_;
-
-  // ProfileKeyedService
-  virtual void Shutdown() OVERRIDE;
-
-  // NotificationObserver
-  virtual void Observe(int type,
-                       const content::NotificationSource& source,
-                       const content::NotificationDetails& details) OVERRIDE;
-
-  // Called when NOTIFICATION_OMNIBOX_OPENED_URL is observed.
-  void OnOmniboxOpenedUrl(const AutocompleteLog& log);
-
-  // Deletes any old or invalid entries from the local caches. |url_db| and
-  // |id_list| must not be NULL. Every row id deleted will be added to id_list.
-  void DeleteOldIdsFromCaches(
-      history::URLDatabase* url_db,
-      std::vector<NetworkActionPredictorDatabase::Row::Id>* id_list);
-
-  // Called to delete any old or invalid entries from the database. Called after
-  // the local caches are created once the history service is available.
-  void DeleteOldEntries(history::URLDatabase* url_db);
-
-  // Called to populate the local caches. This also calls DeleteOldEntries
-  // if the history service is available, or registers for the notification of
-  // it becoming available.
-  void CreateCaches(
-      std::vector<NetworkActionPredictorDatabase::Row>* row_buffer);
-
-  // Attempts to call DeleteOldEntries if the in-memory database has been loaded
-  // by |service|. Returns success as a boolean.
-  bool TryDeleteOldEntries(HistoryService* service);
-
-  // Uses local caches to calculate an exact percentage prediction that the user
-  // will take a particular match given what they have typed. |is_in_db| is set
-  // to differentiate trivial zero results resulting from a match not being
-  // found from actual zero results where the calculation returns 0.0.
-  double CalculateConfidence(const string16& user_text,
-                             const AutocompleteMatch& match,
-                             bool* is_in_db) const;
-
-  // Calculates the confidence for an entry in the DBCacheMap.
-  double CalculateConfidenceForDbEntry(DBCacheMap::const_iterator iter) const;
-
-  // Adds a row to the database and caches.
-  void AddRow(const DBCacheKey& key,
-              const NetworkActionPredictorDatabase::Row& row);
-
-  // Updates a row in the database and the caches.
-  void UpdateRow(DBCacheMap::iterator it,
-                 const NetworkActionPredictorDatabase::Row& row);
-
-  // Removes all rows from the database and caches.
-  void DeleteAllRows();
-
-  // Removes rows from the database and caches that contain a URL in |rows|.
-  void DeleteRowsWithURLs(const history::URLRows& rows);
-
-  // Used to batch operations on the database.
-  void BeginTransaction();
-  void CommitTransaction();
-
-  Profile* profile_;
-  scoped_refptr<NetworkActionPredictorDatabase> db_;
-  content::NotificationRegistrar notification_registrar_;
-
-  // This is cleared after every Omnibox navigation.
-  std::vector<TransitionalMatch> transitional_matches_;
-
-  // This allows us to predict the effect of confidence threshold changes on
-  // accuracy.
-  mutable std::vector<std::pair<GURL, double> > tracked_urls_;
-
-  DBCacheMap db_cache_;
-  DBIdCacheMap db_id_cache_;
-
-  bool initialized_;
-
-  DISALLOW_COPY_AND_ASSIGN(NetworkActionPredictor);
-};
-
-#endif  // CHROME_BROWSER_AUTOCOMPLETE_NETWORK_ACTION_PREDICTOR_H_