Database support for GDataDirectoryService.

chrome/browser/chromeos/gdata/gdata_files.h

 // 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_CHROMEOS_GDATA_GDATA_FILES_H_
 #define CHROME_BROWSER_CHROMEOS_GDATA_GDATA_FILES_H_
 
+#include <leveldb/db.h>
 #include <map>
 #include <string>
 
 #include "base/callback.h"
 #include "base/gtest_prod_util.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/singleton.h"
 #include "base/memory/weak_ptr.h"
 #include "base/platform_file.h"
 #include "base/synchronization/lock.h"
 #include "chrome/browser/chromeos/gdata/gdata_params.h"
 #include "chrome/browser/chromeos/gdata/gdata_uploader.h"
 #include "chrome/browser/chromeos/gdata/gdata_wapi_parser.h"
 #include "chrome/browser/profiles/profile_keyed_service.h"
 #include "chrome/browser/profiles/profile_keyed_service_factory.h"
 
+namespace base {
+class SequencedTaskRunner;
+}  // namespace base
+
 namespace gdata {
 
 class GDataFile;
 class GDataDirectory;
 class GDataDirectoryService;
 
 class GDataEntryProto;
 class GDataDirectoryProto;
 class GDataRootDirectoryProto;
 class PlatformFileInfoProto;
@@ skipping 281 matching lines @@
   // entry instance.
   bool RemoveChild(GDataEntry* entry);
 
   // Collection of children GDataEntry items.
   GDataFileCollection child_files_;
   GDataDirectoryCollection child_directories_;
 
   DISALLOW_COPY_AND_ASSIGN(GDataDirectory);
 };
 
+// TODO(achuith,hashimoto,satorux): Move this to a separate file.
 // Class to handle GDataEntry* lookups, add/remove GDataEntry*.
 class GDataDirectoryService {
  public:
   // Callback for GetEntryByResourceIdAsync.
   typedef base::Callback<void(GDataEntry* entry)> GetEntryByResourceIdCallback;
 
   GDataDirectoryService();
   ~GDataDirectoryService();
 
   GDataDirectory* root() { return root_.get(); }
@@ skipping 34 matching lines @@
                                  const GetEntryByResourceIdCallback& callback);
 
   // Replaces file entry with the same resource id as |fresh_file| with its
   // fresh value |fresh_file|.
   void RefreshFile(scoped_ptr<GDataFile> fresh_file);
 
   // Serializes/Parses to/from string via proto classes.
   void SerializeToString(std::string* serialized_proto) const;
   bool ParseFromString(const std::string& serialized_proto);
 
+  // Restore from and save to database.
+  void InitFromDB(const FilePath& db_path,
+                  base::SequencedTaskRunner* blocking_task_runner);

[satorux1, 2012/07/24 16:30:34]

Loading from DB can fail, right? If so, the caller of this function should have
a way to tell if it's failed. Maybe add a callback parameter which is called
upon completion/failure?

+  void SaveResourceMapToDB();

[hashimoto, 2012/07/24 08:41:51]

Where is this method used?

+
  private:
   // A map table of file's resource string to its GDataFile* entry.
   typedef std::map<std::string, GDataEntry*> ResourceMap;
+  // Map of resource id and serialized GDataEntry.
+  typedef std::map<std::string, std::string> SerializedMap;
+
+  // Helper functions for restoring from and saving to the database.
+  void ReadFromDBOnBlockingThread(const FilePath& db_path,
+                                  SerializedMap* serialized_resources);
+  void InitDBOnBlockingThread(const FilePath& db_path);
+  void InitResourceMapOnUIThread(SerializedMap* serialized_resources);
+  void SaveSerializedToDBOnBlockingThread(
+      const SerializedMap& serialized_resources);
+
+  scoped_refptr<base::SequencedTaskRunner> blocking_task_runner_;
+
+  ResourceMap resource_map_;
+  scoped_ptr<leveldb::DB> level_db_;
+  FilePath db_path_;
 
   scoped_ptr<GDataDirectory> root_;  // Stored in the serialized proto.
-  ResourceMap resource_map_;
 
   base::Time last_serialized_;
   size_t serialized_size_;
   int largest_changestamp_;  // Stored in the serialized proto.
   ContentOrigin origin_;
 
   DISALLOW_COPY_AND_ASSIGN(GDataDirectoryService);
 };
 
 }  // namespace gdata
 
 #endif  // CHROME_BROWSER_CHROMEOS_GDATA_GDATA_FILES_H_