1 // Copyright 2013 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 #ifndef CHROME_BROWSER_SYNC_FILE_SYSTEM_LOCAL_LOCAL_FILE_CHANGE_TRACKER_H_ 6 #define CHROME_BROWSER_SYNC_FILE_SYSTEM_LOCAL_LOCAL_FILE_CHANGE_TRACKER_H_ 7 8 #include <deque> 9 #include <map> 10 #include <string> 11 12 #include "base/basictypes.h" 13 #include "base/compiler_specific.h" 14 #include "base/files/file_path.h" 15 #include "base/memory/ref_counted.h" 16 #include "base/memory/scoped_ptr.h" 17 #include "base/synchronization/lock.h" 18 #include "chrome/browser/sync_file_system/file_change.h" 19 #include "chrome/browser/sync_file_system/sync_status_code.h" 20 #include "webkit/browser/fileapi/file_observers.h" 21 #include "webkit/browser/fileapi/file_system_url.h" 22 23 namespace base { 24 class SequencedTaskRunner; 25 } 26 27 namespace fileapi { 28 class FileSystemContext; 29 class FileSystemURL; 30 } 31 32 namespace leveldb { 33 class Env; 34 } 35 36 namespace sync_file_system { 37 38 // Tracks local file changes for cloud-backed file systems. 39 // All methods must be called on the file_task_runner given to the constructor. 40 // Owned by FileSystemContext. 41 class LocalFileChangeTracker 42 : public fileapi::FileUpdateObserver, 43 public fileapi::FileChangeObserver { 44 public: 45 // |file_task_runner| must be the one where the observee file operations run. 46 // (So that we can make sure DB operations are done before actual update 47 // happens) 48 LocalFileChangeTracker(const base::FilePath& base_path, 49 leveldb::Env* env_override, 50 base::SequencedTaskRunner* file_task_runner); 51 virtual ~LocalFileChangeTracker(); 52 53 // FileUpdateObserver overrides. 54 virtual void OnStartUpdate(const fileapi::FileSystemURL& url) OVERRIDE; OnUpdate(const fileapi::FileSystemURL & url,int64 delta)55 virtual void OnUpdate( 56 const fileapi::FileSystemURL& url, int64 delta) OVERRIDE {} 57 virtual void OnEndUpdate(const fileapi::FileSystemURL& url) OVERRIDE; 58 59 // FileChangeObserver overrides. 60 virtual void OnCreateFile(const fileapi::FileSystemURL& url) OVERRIDE; 61 virtual void OnCreateFileFrom(const fileapi::FileSystemURL& url, 62 const fileapi::FileSystemURL& src) OVERRIDE; 63 virtual void OnRemoveFile(const fileapi::FileSystemURL& url) OVERRIDE; 64 virtual void OnModifyFile(const fileapi::FileSystemURL& url) OVERRIDE; 65 virtual void OnCreateDirectory(const fileapi::FileSystemURL& url) OVERRIDE; 66 virtual void OnRemoveDirectory(const fileapi::FileSystemURL& url) OVERRIDE; 67 68 // Retrieves an array of |url| which have more than one pending changes. 69 // If |max_urls| is non-zero (recommended in production code) this 70 // returns URLs up to the number from the ones that have smallest 71 // change_seq numbers (i.e. older changes). 72 void GetNextChangedURLs(std::deque<fileapi::FileSystemURL>* urls, 73 int max_urls); 74 75 // Returns all changes recorded for the given |url|. 76 // Note that this also returns demoted changes. 77 // This should be called after writing is disabled. 78 void GetChangesForURL(const fileapi::FileSystemURL& url, 79 FileChangeList* changes); 80 81 // Clears the pending changes recorded in this tracker for |url|. 82 void ClearChangesForURL(const fileapi::FileSystemURL& url); 83 84 // Creates a fresh (empty) in-memory record for |url|. 85 // Note that new changes are recorded to the mirror too. 86 void CreateFreshMirrorForURL(const fileapi::FileSystemURL& url); 87 88 // Removes a mirror for |url|, and commits the change status to database. 89 void RemoveMirrorAndCommitChangesForURL(const fileapi::FileSystemURL& url); 90 91 // Resets the changes to the ones recorded in mirror for |url|, and 92 // commits the updated change status to database. 93 void ResetToMirrorAndCommitChangesForURL(const fileapi::FileSystemURL& url); 94 95 // Re-inserts changes into the separate demoted_changes_ queue. They won't 96 // be fetched by GetNextChangedURLs() unless PromoteDemotedChanges() is 97 // called. 98 void DemoteChangesForURL(const fileapi::FileSystemURL& url); 99 100 // Promotes all demoted changes to the normal queue. Returns true if it has 101 // promoted any changes. 102 bool PromoteDemotedChanges(); 103 104 // Called by FileSyncService at the startup time to restore last dirty changes 105 // left after the last shutdown (if any). 106 SyncStatusCode Initialize(fileapi::FileSystemContext* file_system_context); 107 108 // Resets all the changes recorded for the given |origin| and |type|. 109 // TODO(kinuko,nhiroki): Ideally this should be automatically called in 110 // DeleteFileSystem via QuotaUtil::DeleteOriginDataOnFileThread. 111 void ResetForFileSystem(const GURL& origin, fileapi::FileSystemType type); 112 113 // This method is (exceptionally) thread-safe. num_changes()114 int64 num_changes() const { 115 base::AutoLock lock(num_changes_lock_); 116 return num_changes_; 117 } 118 119 private: 120 class TrackerDB; 121 friend class CannedSyncableFileSystem; 122 friend class LocalFileChangeTrackerTest; 123 friend class LocalFileSyncContext; 124 friend class LocalFileSyncContextTest; 125 friend class SyncableFileSystemTest; 126 127 struct ChangeInfo { 128 ChangeInfo(); 129 ~ChangeInfo(); 130 FileChangeList change_list; 131 int64 change_seq; 132 }; 133 134 typedef std::map<fileapi::FileSystemURL, ChangeInfo, 135 fileapi::FileSystemURL::Comparator> 136 FileChangeMap; 137 typedef std::map<int64, fileapi::FileSystemURL> ChangeSeqMap; 138 139 void UpdateNumChanges(); 140 141 // This does mostly same as calling GetNextChangedURLs with max_url=0 142 // except that it returns urls in set rather than in deque. 143 // Used only in testings. 144 void GetAllChangedURLs(fileapi::FileSystemURLSet* urls); 145 146 // Used only in testings. 147 void DropAllChanges(); 148 149 // Database related methods. 150 SyncStatusCode MarkDirtyOnDatabase(const fileapi::FileSystemURL& url); 151 SyncStatusCode ClearDirtyOnDatabase(const fileapi::FileSystemURL& url); 152 153 SyncStatusCode CollectLastDirtyChanges( 154 fileapi::FileSystemContext* file_system_context); 155 void RecordChange(const fileapi::FileSystemURL& url, 156 const FileChange& change); 157 158 static void RecordChangeToChangeMaps(const fileapi::FileSystemURL& url, 159 const FileChange& change, 160 int change_seq, 161 FileChangeMap* changes, 162 ChangeSeqMap* change_seqs); 163 164 bool initialized_; 165 166 scoped_refptr<base::SequencedTaskRunner> file_task_runner_; 167 168 FileChangeMap changes_; 169 ChangeSeqMap change_seqs_; 170 171 FileChangeMap mirror_changes_; // For mirrors. 172 FileChangeMap demoted_changes_; // For demoted changes. 173 174 scoped_ptr<TrackerDB> tracker_db_; 175 176 // Change sequence number. Briefly gives a hint about the order of changes, 177 // but they are updated when a new change comes on the same file (as 178 // well as Drive's changestamps). 179 int64 current_change_seq_; 180 181 // This can be accessed on any threads (with num_changes_lock_). 182 int64 num_changes_; 183 mutable base::Lock num_changes_lock_; 184 185 DISALLOW_COPY_AND_ASSIGN(LocalFileChangeTracker); 186 }; 187 188 } // namespace sync_file_system 189 190 #endif // CHROME_BROWSER_SYNC_FILE_SYSTEM_LOCAL_LOCAL_FILE_CHANGE_TRACKER_H_ 191