resource_metadata_storage.h revision c2e0dbddbe15c98d52c4786dac06cb8952a8ae6d 
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_CHROMEOS_DRIVE_RESOURCE_METADATA_STORAGE_H_
6#define CHROME_BROWSER_CHROMEOS_DRIVE_RESOURCE_METADATA_STORAGE_H_
7
8#include <string>
9#include <vector>
10
11#include "base/basictypes.h"
12#include "base/callback_forward.h"
13#include "base/files/file_path.h"
14#include "base/memory/scoped_ptr.h"
15
16namespace leveldb {
17class DB;
18}
19
20namespace drive {
21
22class ResourceEntry;
23class ResourceMetadataHeader;
24
25typedef base::Callback<void(const ResourceEntry& entry)> IterateCallback;
26
27// Storage for ResourceMetadata which is responsible to manage entry info
28// and child-parent relationships between entries.
29class ResourceMetadataStorage {
30 public:
31  // This should be incremented when incompatibility change is made to DB
32  // format.
33  static const int kDBVersion = 5;
34
35  explicit ResourceMetadataStorage(const base::FilePath& directory_path);
36  virtual ~ResourceMetadataStorage();
37
38  // Initializes this object.
39  bool Initialize();
40
41  // Sets the largest changestamp.
42  bool SetLargestChangestamp(int64 largest_changestamp);
43
44  // Gets the largest changestamp.
45  int64 GetLargestChangestamp();
46
47  // Puts the entry to this storage.
48  bool PutEntry(const ResourceEntry& entry);
49
50  // Returns an entry stored in this storage.
51  scoped_ptr<ResourceEntry> GetEntry(const std::string& resource_id);
52
53  // Removes an entry from this storage.
54  bool RemoveEntry(const std::string& resource_id);
55
56  // Iterates over entries stored in this storage.
57  void Iterate(const IterateCallback& callback);
58
59  // Returns resource ID of the parent's child.
60  std::string GetChild(const std::string& parent_resource_id,
61                       const std::string& child_name);
62
63  // Returns resource IDs of the parent's children.
64  void GetChildren(const std::string& parent_resource_id,
65                   std::vector<std::string>* children);
66
67 private:
68  friend class ResourceMetadataStorageTest;
69
70  // Returns a string to be used as a key for child entry.
71  static std::string GetChildEntryKey(const std::string& parent_resource_id,
72                                      const std::string& child_name);
73
74  // Puts header.
75  bool PutHeader(const ResourceMetadataHeader& header);
76
77  // Gets header.
78  scoped_ptr<ResourceMetadataHeader> GetHeader();
79
80  // Checks validity of the data.
81  bool CheckValidity();
82
83  // Path to the directory where the data is stored.
84  base::FilePath directory_path_;
85
86  // Entries stored in this storage.
87  scoped_ptr<leveldb::DB> resource_map_;
88
89  DISALLOW_COPY_AND_ASSIGN(ResourceMetadataStorage);
90};
91
92}  // namespace drive
93
94#endif  // CHROME_BROWSER_CHROMEOS_DRIVE_RESOURCE_METADATA_STORAGE_H_
95