drive: DriveIntegrationService owns ResourceMetadataStorage

chrome/browser/chromeos/drive/resource_metadata_storage.h

 // 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 CHROME_BROWSER_CHROMEOS_DRIVE_RESOURCE_METADATA_STORAGE_H_
 #define CHROME_BROWSER_CHROMEOS_DRIVE_RESOURCE_METADATA_STORAGE_H_
 
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/files/file_path.h"
+#include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "chrome/browser/chromeos/drive/drive.pb.h"
 
+namespace base {
+class SequencedTaskRunner;
+}
+
 namespace leveldb {
 class DB;
 class Iterator;
 }
 
 namespace drive {
 
 class ResourceEntry;
 class ResourceMetadataHeader;
 
+namespace internal {
+
 // Storage for ResourceMetadata which is responsible to manage resource
 // entries and child-parent relationships between entries.
 class ResourceMetadataStorage {
  public:
   // This should be incremented when incompatibility change is made to DB
   // format.
   static const int kDBVersion = 6;
 
   // Object to iterate over entries stored in this storage.
   class Iterator {
@@ skipping 48 matching lines @@
     // Used to implement Advance().
     void AdvanceInternal();
 
     scoped_ptr<leveldb::Iterator> it_;
     std::string resource_id_;
     FileCacheEntry entry_;
 
     DISALLOW_COPY_AND_ASSIGN(CacheEntryIterator);
   };
 
-  explicit ResourceMetadataStorage(const base::FilePath& directory_path);
-  virtual ~ResourceMetadataStorage();
+  ResourceMetadataStorage(const base::FilePath& directory_path,
+                          base::SequencedTaskRunner* blocking_task_runner);
+
+  const base::FilePath& directory_path() const { return directory_path_; }
+
+  // Destroys this object.
+  void Destroy();
 
   // Initializes this object.
   bool Initialize();
 
   // Sets the largest changestamp.
   bool SetLargestChangestamp(int64 largest_changestamp);
 
   // Gets the largest changestamp.
   int64 GetLargestChangestamp();
 
@@ skipping 26 matching lines @@
 
   // Removes a cache entry from this storage.
   bool RemoveCacheEntry(const std::string& resource_id);
 
   // Returns an object to iterate over cache entries stored in this storage.
   scoped_ptr<CacheEntryIterator> GetCacheEntryIterator();
 
  private:
   friend class ResourceMetadataStorageTest;
 
+  // To destruct this object, use Destroy().
+  ~ResourceMetadataStorage();
+
+  // Used to implement Destroy().
+  void DestroyOnBlockingPool();
+
   // Returns a string to be used as a key for child entry.
   static std::string GetChildEntryKey(const std::string& parent_resource_id,
                                       const std::string& child_name);
 
   // Puts header.
   bool PutHeader(const ResourceMetadataHeader& header);
 
   // Gets header.
   bool GetHeader(ResourceMetadataHeader* out_header);
 
   // Checks validity of the data.
   bool CheckValidity();
 
   // Path to the directory where the data is stored.
   base::FilePath directory_path_;
 
   // Entries stored in this storage.
   scoped_ptr<leveldb::DB> resource_map_;
 
+  scoped_refptr<base::SequencedTaskRunner> blocking_task_runner_;
+
   DISALLOW_COPY_AND_ASSIGN(ResourceMetadataStorage);
 };
 
+}  // namespace internal
 }  // namespace drive
 
 #endif  // CHROME_BROWSER_CHROMEOS_DRIVE_RESOURCE_METADATA_STORAGE_H_