[SyncFS] Use pointers to MetadataDatabaseIndexInterface

chrome/browser/sync_file_system/drive_backend/metadata_database_index_interface.h

+// Copyright 2014 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_SYNC_FILE_SYSTEM_DRIVE_BACKEND_METADATA_DATABASE_INDEX_INTERFACE_H_
+#define CHROME_BROWSER_SYNC_FILE_SYSTEM_DRIVE_BACKEND_METADATA_DATABASE_INDEX_INTERFACE_H_
+
+#include <string>
+#include <vector>
+
+#include "base/memory/scoped_ptr.h"
+
+namespace sync_file_system {
+namespace drive_backend {
+
+struct ParentIDAndTitle {
+  int64 parent_id;
+  std::string title;
+
+  ParentIDAndTitle();
+  ParentIDAndTitle(int64 parent_id, const std::string& title);
+};
+
+bool operator==(const ParentIDAndTitle& left, const ParentIDAndTitle& right);
+bool operator<(const ParentIDAndTitle& left, const ParentIDAndTitle& right);
+
+}  // namespace drive_backend
+}  // namespace sync_file_system
+
+namespace BASE_HASH_NAMESPACE {
+
+#if defined(COMPILER_GCC)
+template<> struct hash<sync_file_system::drive_backend::ParentIDAndTitle> {
+  std::size_t operator()(
+      const sync_file_system::drive_backend::ParentIDAndTitle& v) const {
+    return base::HashInts64(v.parent_id, hash<std::string>()(v.title));
+  }
+};
+#elif defined(COMPILER_MSVC)
+inline size_t hash_value(
+    const sync_file_system::drive_backend::ParentIDAndTitle& v) {
+  return base::HashInts64(v.parent_id, hash_value(v.title));
+}
+#endif  // COMPILER

[tzik, 2014/06/20 03:57:47]

Can we move this block to the original file? I think this is only for on-memory
index.

[peria, 2014/06/20 04:44:22]

Done.

+
+}  // namespace BASE_HASH_NAMESPACE
+
+namespace sync_file_system {
+namespace drive_backend {
+
+class FileMetadata;
+class FileTracker;
+
+// Maintains indexes of MetadataDatabase.  This class doesn't modify database
+// entries on memory nor on disk.

[tzik, 2014/06/20 03:57:47]

Could you update this comment? I think this is no longer true or is going to be
not true.
Just removing second sentence is fine.

[peria, 2014/06/20 04:44:23]

Done.

+class MetadataDatabaseIndexInterface {
+ public:
+  MetadataDatabaseIndexInterface() {}
+  virtual ~MetadataDatabaseIndexInterface() {}
+
+  // Returns FileMetadata identified by |file_id| if exists, otherwise returns
+  // NULL.
+  virtual const FileMetadata* GetFileMetadata(
+      const std::string& file_id) const = 0;
+
+  // Returns FileTracker identified by |tracker_id| if exists, otherwise returns
+  // NULL.
+  virtual const FileTracker* GetFileTracker(int64 tracker_id) const = 0;
+
+  // Stores |metadata| and updates indexes.
+  // This overwrites existing FileMetadata for the same |file_id|.
+  virtual void StoreFileMetadata(scoped_ptr<FileMetadata> metadata) = 0;
+
+  // Stores |tracker| and updates indexes.
+  // This overwrites existing FileTracker for the same |tracker_id|.
+  virtual void StoreFileTracker(scoped_ptr<FileTracker> tracker) = 0;
+
+  // Removes FileMetadata identified by |file_id| from indexes.
+  virtual void RemoveFileMetadata(const std::string& file_id) = 0;
+
+  // Removes FileTracker identified by |tracker_id| from indexes.
+  virtual void RemoveFileTracker(int64 tracker_id) = 0;
+
+  // Returns a set of FileTracker that have |file_id| as its own.
+  virtual TrackerIDSet GetFileTrackerIDsByFileID(
+      const std::string& file_id) const = 0;
+
+  // Returns an app-root tracker identified by |app_id|.  Returns 0 if not
+  // found.
+  virtual int64 GetAppRootTracker(const std::string& app_id) const = 0;
+
+  // Returns a set of FileTracker that have |parent_tracker_id| and |title|.
+  virtual TrackerIDSet GetFileTrackerIDsByParentAndTitle(
+      int64 parent_tracker_id,
+      const std::string& title) const = 0;
+
+  virtual std::vector<int64> GetFileTrackerIDsByParent(
+      int64 parent_tracker_id) const = 0;
+
+  // Returns the |file_id| of a file that has multiple trackers.
+  virtual std::string PickMultiTrackerFileID() const = 0;
+
+  // Returns a pair of |parent_tracker_id| and |title| that has multiple file
+  // at the path.
+  virtual ParentIDAndTitle PickMultiBackingFilePath() const = 0;
+
+  // Returns a FileTracker whose |dirty| is set and which isn't demoted.
+  // Returns 0 if not found.
+  virtual int64 PickDirtyTracker() const = 0;
+
+  // Demotes a dirty tracker.
+  virtual void DemoteDirtyTracker(int64 tracker_id) = 0;
+
+  virtual bool HasDemotedDirtyTracker() const = 0;
+
+  // Promotes all demoted dirty trackers to normal dirty trackers.
+  virtual void PromoteDemotedDirtyTrackers() = 0;
+
+  virtual size_t CountDirtyTracker() const = 0;
+  virtual size_t CountFileMetadata() const = 0;
+  virtual size_t CountFileTracker() const = 0;
+
+  virtual std::vector<std::string> GetRegisteredAppIDs() const = 0;
+  virtual std::vector<int64> GetAllTrackerIDs() const = 0;
+  virtual std::vector<std::string> GetAllMetadataIDs() const = 0;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(MetadataDatabaseIndexInterface);
+};
+
+}  // namespace drive_backend
+}  // namespace sync_file_system
+
+#endif  // CHROME_BROWSER_SYNC_FILE_SYSTEM_DRIVE_BACKEND_METADATA_DATABASE_INDEX_INTERFACE_H_