// 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_H_
#define CHROME_BROWSER_PREDICTORS_AUTOCOMPLETE_ACTION_PREDICTOR_H_
#include <map>
#include "base/gtest_prod_util.h"
#include "base/memory/ref_counted.h"
#include "base/memory/scoped_ptr.h"
#include "base/memory/weak_ptr.h"
#include "base/strings/string16.h"
#include "chrome/browser/history/history_types.h"
#include "chrome/browser/predictors/autocomplete_action_predictor_table.h"
#include "components/keyed_service/core/keyed_service.h"
#include "content/public/browser/navigation_controller.h"
#include "content/public/browser/notification_observer.h"
#include "content/public/browser/notification_registrar.h"
#include "url/gurl.h"
struct AutocompleteMatch;
class AutocompleteResult;
class HistoryService;
struct OmniboxLog;
class PredictorsHandler;
class Profile;
namespace content {
class SessionStorageNamespace;
}
namespace gfx {
class Size;
}
namespace history {
class URLDatabase;
}
namespace prerender {
class PrerenderHandle;
}
namespace predictors {
// This class is responsible for determining the correct predictive network
// action to take given for a given AutocompleteMatch and entered text. It can
// be instantiated for both normal and incognito profiles. For normal profiles,
// it uses an AutocompleteActionPredictorTable 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. For incognito profiles, there is no table; the
// local caches are copied from the main profile at creation and from there on
// are the only thing used.
//
// This class 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 AutocompleteActionPredictor
: public KeyedService,
public content::NotificationObserver,
public base::SupportsWeakPtr<AutocompleteActionPredictor> {
public:
enum Action {
ACTION_PRERENDER = 0,
ACTION_PRECONNECT,
ACTION_NONE,
LAST_PREDICT_ACTION = ACTION_NONE
};
explicit AutocompleteActionPredictor(Profile* profile);
virtual ~AutocompleteActionPredictor();
// 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 base::string16& user_text,
const AutocompleteResult& result);
// Clears any transitional matches that have been registered. Called when, for
// example, the OmniboxEditModel 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 base::string16& user_text,
const AutocompleteMatch& match) const;
// Begin prerendering |url| with |session_storage_namespace|. The |size| gives
// the initial size for the target prerender. The predictor will run at most
// one prerender at a time, so launching a prerender will cancel our previous
// prerenders (if any).
void StartPrerendering(
const GURL& url,
const content::SessionStorageNamespaceMap& session_storage_namespace_map,
const gfx::Size& size);
// 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 AutocompleteActionPredictorTest;
friend class ::PredictorsHandler;
struct TransitionalMatch {
TransitionalMatch();
~TransitionalMatch();
base::string16 user_text;
std::vector<GURL> urls;
bool operator==(const base::string16& other_user_text) const {
return user_text == other_user_text;
}
};
struct DBCacheKey {
base::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, AutocompleteActionPredictorTable::Row::Id>
DBIdCacheMap;
static const int kMaximumDaysToKeepEntry;
// NotificationObserver
virtual void Observe(int type,
const content::NotificationSource& source,
const content::NotificationDetails& details) OVERRIDE;
// The first step in initializing the predictor is accessing the database and
// building the local cache. This should be delayed until after critical DB
// and IO processes have completed.
void CreateLocalCachesFromDatabase();
// 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);
// Called when NOTIFICATION_OMNIBOX_OPENED_URL is observed.
void OnOmniboxOpenedUrl(const OmniboxLog& log);
// Adds and updates rows in the database and caches.
void AddAndUpdateRows(
const AutocompleteActionPredictorTable::Rows& rows_to_add,
const AutocompleteActionPredictorTable::Rows& rows_to_update);
// 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<AutocompleteActionPredictorTable::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);
// 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);
// 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<AutocompleteActionPredictorTable::Row::Id>* id_list);
// Called on an incognito-owned predictor to copy the current caches from the
// main profile.
void CopyFromMainProfile();
// Registers for notifications and sets the |initialized_| flag.
void FinishInitialization();
// 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 base::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;
Profile* profile_;
// Set when this is a predictor for an incognito profile.
AutocompleteActionPredictor* main_profile_predictor_;
// Set when this is a predictor for a non-incognito profile, and the incognito
// profile creates a predictor. If this is non-NULL when we finish
// initialization, we should call CopyFromMainProfile() on it.
AutocompleteActionPredictor* incognito_predictor_;
// The backing data store. This is NULL for incognito-owned predictors.
scoped_refptr<AutocompleteActionPredictorTable> table_;
content::NotificationRegistrar notification_registrar_;
// This is cleared after every Omnibox navigation.
std::vector<TransitionalMatch> transitional_matches_;
scoped_ptr<prerender::PrerenderHandle> prerender_handle_;
// This allows us to predict the effect of confidence threshold changes on
// accuracy. This is cleared after every omnibox navigation.
mutable std::vector<std::pair<GURL, double> > tracked_urls_;
// Local caches of the data store. For incognito-owned predictors this is the
// only copy of the data.
DBCacheMap db_cache_;
DBIdCacheMap db_id_cache_;
bool initialized_;
DISALLOW_COPY_AND_ASSIGN(AutocompleteActionPredictor);
};
} // namespace predictors
#endif // CHROME_BROWSER_PREDICTORS_AUTOCOMPLETE_ACTION_PREDICTOR_H_