1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 // The InMemoryHistoryBackend is a wrapper around the in-memory URL database. 6 // It maintains an in-memory cache of a subset of history that is required for 7 // low-latency operations, such as in-line autocomplete. 8 // 9 // The in-memory cache provides the following guarantees: 10 // (1.) It will always contain URLRows that either have a |typed_count| > 0; or 11 // that have a corresponding search term, in which case information about 12 // the search term is also stored. 13 // (2.) It will be an actual subset, i.e., it will contain verbatim data, and 14 // will never contain more data that can be found in the main database. 15 // 16 // The InMemoryHistoryBackend is created on the history thread and passed to the 17 // main thread where operations can be completed synchronously. It listens for 18 // notifications from the "regular" history backend and keeps itself in sync. 19 20 #ifndef CHROME_BROWSER_HISTORY_IN_MEMORY_HISTORY_BACKEND_H_ 21 #define CHROME_BROWSER_HISTORY_IN_MEMORY_HISTORY_BACKEND_H_ 22 23 #include <string> 24 25 #include "base/basictypes.h" 26 #include "base/gtest_prod_util.h" 27 #include "base/memory/scoped_ptr.h" 28 #include "components/history/core/browser/keyword_id.h" 29 #include "content/public/browser/notification_observer.h" 30 #include "content/public/browser/notification_registrar.h" 31 32 class Profile; 33 34 namespace base { 35 class FilePath; 36 } 37 38 namespace history { 39 40 class InMemoryDatabase; 41 struct KeywordSearchUpdatedDetails; 42 struct KeywordSearchDeletedDetails; 43 class URLDatabase; 44 class URLRow; 45 struct URLsDeletedDetails; 46 struct URLsModifiedDetails; 47 48 class InMemoryHistoryBackend : public content::NotificationObserver { 49 public: 50 InMemoryHistoryBackend(); 51 virtual ~InMemoryHistoryBackend(); 52 53 // Initializes the backend from the history database pointed to by the 54 // full path in |history_filename|. 55 bool Init(const base::FilePath& history_filename); 56 57 // Does initialization work when this object is attached to the history 58 // system on the main thread. The argument is the profile with which the 59 // attached history service is under. 60 void AttachToHistoryService(Profile* profile); 61 62 // Deletes all search terms for the specified keyword. 63 void DeleteAllSearchTermsForKeyword(KeywordID keyword_id); 64 65 // Returns the underlying database associated with this backend. The current 66 // autocomplete code was written fro this, but it should probably be removed 67 // so that it can deal directly with this object, rather than the DB. 68 InMemoryDatabase* db() const { 69 return db_.get(); 70 } 71 72 // Notification callback. 73 virtual void Observe(int type, 74 const content::NotificationSource& source, 75 const content::NotificationDetails& details) OVERRIDE; 76 77 private: 78 FRIEND_TEST_ALL_PREFIXES(HistoryBackendTest, DeleteAll); 79 80 // Handler for HISTORY_URL_VISITED and HISTORY_URLS_MODIFIED. 81 void OnURLVisitedOrModified(const URLRow& url_row); 82 83 // Handler for HISTORY_URLS_DELETED. 84 void OnURLsDeleted(const URLsDeletedDetails& details); 85 86 // Handler for HISTORY_KEYWORD_SEARCH_TERM_UPDATED. 87 void OnKeywordSearchTermUpdated(const KeywordSearchUpdatedDetails& details); 88 89 // Handler for HISTORY_KEYWORD_SEARCH_TERM_DELETED. 90 void OnKeywordSearchTermDeleted(const KeywordSearchDeletedDetails& details); 91 92 content::NotificationRegistrar registrar_; 93 94 scoped_ptr<InMemoryDatabase> db_; 95 96 // The profile that this object is attached. May be NULL before 97 // initialization. 98 Profile* profile_; 99 100 DISALLOW_COPY_AND_ASSIGN(InMemoryHistoryBackend); 101 }; 102 103 } // namespace history 104 105 #endif // CHROME_BROWSER_HISTORY_IN_MEMORY_HISTORY_BACKEND_H_ 106