1 files changed, 150 insertions, 0 deletions
diff --git a/webkit/browser/fileapi/syncable/local_file_change_tracker.h b/webkit/browser/fileapi/syncable/local_file_change_tracker.h
new file mode 100644
index 0000000..6d58cf2
--- /dev/null
+++ b/webkit/browser/fileapi/syncable/local_file_change_tracker.h
@@ -0,0 +1,150 @@
+// Copyright 2013 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 WEBKIT_BROWSER_FILEAPI_SYNCABLE_LOCAL_FILE_CHANGE_TRACKER_H_
+#define WEBKIT_BROWSER_FILEAPI_SYNCABLE_LOCAL_FILE_CHANGE_TRACKER_H_
+
+#include <deque>
+#include <map>
+#include <string>
+
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+#include "base/files/file_path.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/synchronization/lock.h"
+#include "webkit/browser/fileapi/file_observers.h"
+#include "webkit/browser/fileapi/file_system_url.h"
+#include "webkit/browser/fileapi/syncable/file_change.h"
+#include "webkit/browser/fileapi/syncable/sync_status_code.h"
+#include "webkit/storage/webkit_storage_export.h"
+
+namespace base {
+class SequencedTaskRunner;
+}
+
+namespace fileapi {
+class FileSystemContext;
+class FileSystemURL;
+}
+
+namespace sync_file_system {
+
+// Tracks local file changes for cloud-backed file systems.
+// All methods must be called on the file_task_runner given to the constructor.
+// Owned by FileSystemContext.
+class WEBKIT_STORAGE_EXPORT LocalFileChangeTracker
+    : public fileapi::FileUpdateObserver,
+      public fileapi::FileChangeObserver {
+ public:
+  // |file_task_runner| must be the one where the observee file operations run.
+  // (So that we can make sure DB operations are done before actual update
+  // happens)
+  LocalFileChangeTracker(const base::FilePath& base_path,
+                         base::SequencedTaskRunner* file_task_runner);
+  virtual ~LocalFileChangeTracker();
+
+  // FileUpdateObserver overrides.
+  virtual void OnStartUpdate(const fileapi::FileSystemURL& url) OVERRIDE;
+  virtual void OnUpdate(
+      const fileapi::FileSystemURL& url, int64 delta) OVERRIDE {}
+  virtual void OnEndUpdate(const fileapi::FileSystemURL& url) OVERRIDE;
+
+  // FileChangeObserver overrides.
+  virtual void OnCreateFile(const fileapi::FileSystemURL& url) OVERRIDE;
+  virtual void OnCreateFileFrom(const fileapi::FileSystemURL& url,
+                                const fileapi::FileSystemURL& src) OVERRIDE;
+  virtual void OnRemoveFile(const fileapi::FileSystemURL& url) OVERRIDE;
+  virtual void OnModifyFile(const fileapi::FileSystemURL& url) OVERRIDE;
+  virtual void OnCreateDirectory(const fileapi::FileSystemURL& url) OVERRIDE;
+  virtual void OnRemoveDirectory(const fileapi::FileSystemURL& url) OVERRIDE;
+
+  // Retrieves an array of |url| which have more than one pending changes.
+  // If |max_urls| is non-zero (recommended in production code) this
+  // returns URLs up to the number from the ones that have smallest
+  // change_seq numbers (i.e. older changes).
+  void GetNextChangedURLs(std::deque<fileapi::FileSystemURL>* urls,
+                          int max_urls);
+
+  // Returns all changes recorded for the given |url|.
+  // This should be called after writing is disabled.
+  void GetChangesForURL(const fileapi::FileSystemURL& url,
+                        FileChangeList* changes);
+
+  // Clears the pending changes recorded in this tracker for |url|.
+  void ClearChangesForURL(const fileapi::FileSystemURL& url);
+
+  // Called by FileSyncService at the startup time to restore last dirty changes
+  // left after the last shutdown (if any).
+  SyncStatusCode Initialize(fileapi::FileSystemContext* file_system_context);
+
+  // This method is (exceptionally) thread-safe.
+  int64 num_changes() const {
+    base::AutoLock lock(num_changes_lock_);
+    return num_changes_;
+  }
+
+  void UpdateNumChanges();
+
+ private:
+  class TrackerDB;
+  friend class CannedSyncableFileSystem;
+  friend class LocalFileChangeTrackerTest;
+  friend class LocalFileSyncContext;
+  friend class SyncableFileSystemTest;
+
+  struct ChangeInfo {
+    ChangeInfo();
+    ~ChangeInfo();
+    FileChangeList change_list;
+    int64 change_seq;
+  };
+
+  typedef std::map<fileapi::FileSystemURL, ChangeInfo,
+      fileapi::FileSystemURL::Comparator>
+          FileChangeMap;
+  typedef std::map<int64, fileapi::FileSystemURL> ChangeSeqMap;
+
+  // This does mostly same as calling GetNextChangedURLs with max_url=0
+  // except that it returns urls in set rather than in deque.
+  // Used only in testings.
+  void GetAllChangedURLs(fileapi::FileSystemURLSet* urls);
+
+  // Used only in testings.
+  void DropAllChanges();
+
+  // Database related methods.
+  SyncStatusCode MarkDirtyOnDatabase(const fileapi::FileSystemURL& url);
+  SyncStatusCode ClearDirtyOnDatabase(const fileapi::FileSystemURL& url);
+
+  SyncStatusCode CollectLastDirtyChanges(
+      fileapi::FileSystemContext* file_system_context);
+  void RecordChange(const fileapi::FileSystemURL& url,
+                    const FileChange& change);
+
+  bool initialized_;
+
+  scoped_refptr<base::SequencedTaskRunner> file_task_runner_;
+
+  FileChangeMap changes_;
+  ChangeSeqMap change_seqs_;
+
+  scoped_ptr<TrackerDB> tracker_db_;
+
+  // Change sequence number. Briefly gives a hint about the order of changes,
+  // but they are updated when a new change comes on the same file (as
+  // well as Drive's changestamps).
+  int64 current_change_seq_;
+
+  // This can be accessed on any threads (with num_changes_lock_).
+  int64 num_changes_;
+  mutable base::Lock num_changes_lock_;
+
+  DISALLOW_COPY_AND_ASSIGN(LocalFileChangeTracker);
+};
+
+}  // namespace sync_file_system
+
+#endif  // WEBKIT_BROWSER_FILEAPI_SYNCABLE_LOCAL_FILE_CHANGE_TRACKER_H_