1// Copyright (c) 2012 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 STORAGE_BROWSER_FILEAPI_SANDBOX_DIRECTORY_DATABASE_H_
6#define STORAGE_BROWSER_FILEAPI_SANDBOX_DIRECTORY_DATABASE_H_
7
8#include <string>
9#include <vector>
10
11#include "base/files/file.h"
12#include "base/files/file_path.h"
13#include "base/memory/scoped_ptr.h"
14#include "base/time/time.h"
15#include "storage/browser/storage_browser_export.h"
16
17namespace content {
18class SandboxDirectoryDatabaseTest;
19}
20
21namespace tracked_objects {
22class Location;
23}
24
25namespace leveldb {
26class DB;
27class Env;
28class Status;
29class WriteBatch;
30}
31
32namespace storage {
33
34// This class WILL NOT protect you against producing directory loops, giving an
35// empty directory a backing data file, giving two files the same backing file,
36// or pointing to a nonexistent backing file.  It does no file IO other than
37// that involved with talking to its underlying database.  It does not create or
38// in any way touch real files; it only creates path entries in its database.
39
40// TODO(ericu): Safe mode, which does more checks such as the above on debug
41// builds.
42// TODO(ericu): Add a method that will give a unique filename for a data file.
43class STORAGE_EXPORT_PRIVATE SandboxDirectoryDatabase {
44 public:
45  typedef int64 FileId;
46
47  struct STORAGE_EXPORT_PRIVATE FileInfo {
48    FileInfo();
49    ~FileInfo();
50
51    bool is_directory() const {
52      return data_path.empty();
53    }
54
55    FileId parent_id;
56    base::FilePath data_path;
57    base::FilePath::StringType name;
58    // This modification time is valid only for directories, not files, as
59    // FileWriter will get the files out of sync.
60    // For files, look at the modification time of the underlying data_path.
61    base::Time modification_time;
62  };
63
64  SandboxDirectoryDatabase(
65      const base::FilePath& filesystem_data_directory,
66      leveldb::Env* env_override);
67  ~SandboxDirectoryDatabase();
68
69  bool GetChildWithName(
70      FileId parent_id,
71      const base::FilePath::StringType& name,
72      FileId* child_id);
73  bool GetFileWithPath(const base::FilePath& path, FileId* file_id);
74  // ListChildren will succeed, returning 0 children, if parent_id doesn't
75  // exist.
76  bool ListChildren(FileId parent_id, std::vector<FileId>* children);
77  bool GetFileInfo(FileId file_id, FileInfo* info);
78  base::File::Error AddFileInfo(const FileInfo& info, FileId* file_id);
79  bool RemoveFileInfo(FileId file_id);
80  // This does a full update of the FileInfo, and is what you'd use for moves
81  // and renames.  If you just want to update the modification_time, use
82  // UpdateModificationTime.
83  bool UpdateFileInfo(FileId file_id, const FileInfo& info);
84  bool UpdateModificationTime(
85      FileId file_id, const base::Time& modification_time);
86  // This is used for an overwriting move of a file [not a directory] on top of
87  // another file [also not a directory]; we need to alter two files' info in a
88  // single transaction to avoid weird backing file references in the event of a
89  // partial failure.
90  bool OverwritingMoveFile(FileId src_file_id, FileId dest_file_id);
91
92  // This produces the series 0, 1, 2..., starting at 0 when the underlying
93  // filesystem is first created, and maintaining state across
94  // creation/destruction of SandboxDirectoryDatabase objects.
95  bool GetNextInteger(int64* next);
96
97  bool IsDirectory(FileId file_id);
98
99  // Returns true if the database looks consistent with local filesystem.
100  bool IsFileSystemConsistent();
101
102  // Completely deletes contents of the database.
103  bool DestroyDatabase();
104
105 private:
106  enum RecoveryOption {
107    DELETE_ON_CORRUPTION,
108    REPAIR_ON_CORRUPTION,
109    FAIL_ON_CORRUPTION,
110  };
111
112  friend class content::SandboxDirectoryDatabaseTest;
113  friend class ObfuscatedFileUtil;
114
115  bool Init(RecoveryOption recovery_option);
116  bool RepairDatabase(const std::string& db_path);
117  void ReportInitStatus(const leveldb::Status& status);
118  bool StoreDefaultValues();
119  bool GetLastFileId(FileId* file_id);
120  bool AddFileInfoHelper(
121      const FileInfo& info, FileId file_id, leveldb::WriteBatch* batch);
122  bool RemoveFileInfoHelper(FileId file_id, leveldb::WriteBatch* batch);
123  void HandleError(const tracked_objects::Location& from_here,
124                   const leveldb::Status& status);
125
126  const base::FilePath filesystem_data_directory_;
127  leveldb::Env* env_override_;
128  scoped_ptr<leveldb::DB> db_;
129  base::Time last_reported_time_;
130  DISALLOW_COPY_AND_ASSIGN(SandboxDirectoryDatabase);
131};
132
133}  // namespace storage
134
135#endif  // STORAGE_BROWSER_FILEAPI_SANDBOX_DIRECTORY_DATABASE_H_
136