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 CONTENT_BROWSER_DOM_STORAGE_DOM_STORAGE_DATABASE_H_
6#define CONTENT_BROWSER_DOM_STORAGE_DOM_STORAGE_DATABASE_H_
7
8#include <map>
9
10#include "base/files/file_path.h"
11#include "base/gtest_prod_util.h"
12#include "base/memory/scoped_ptr.h"
13#include "base/strings/nullable_string16.h"
14#include "base/strings/string16.h"
15#include "content/common/content_export.h"
16#include "content/common/dom_storage/dom_storage_types.h"
17#include "sql/connection.h"
18
19namespace content {
20
21// Represents a SQLite based backing for DOM storage data. This
22// class is designed to be used on a single thread.
23class CONTENT_EXPORT DOMStorageDatabase {
24 public:
25  static base::FilePath GetJournalFilePath(const base::FilePath& database_path);
26
27  explicit DOMStorageDatabase(const base::FilePath& file_path);
28  virtual ~DOMStorageDatabase();  // virtual for unit testing
29
30  // Reads all the key, value pairs stored in the database and returns
31  // them. |result| is assumed to be empty and any duplicate keys will
32  // be overwritten. If the database exists on disk then it will be
33  // opened. If it does not exist then it will not be created and
34  // |result| will be unmodified.
35  void ReadAllValues(DOMStorageValuesMap* result);
36
37  // Updates the backing database. Will remove all keys before updating
38  // the database if |clear_all_first| is set. Then all entries in
39  // |changes| will be examined - keys mapped to a null NullableString16
40  // will be removed and all others will be inserted/updated as appropriate.
41  bool CommitChanges(bool clear_all_first, const DOMStorageValuesMap& changes);
42
43  // Simple getter for the path we were constructed with.
44  const base::FilePath& file_path() const { return file_path_; }
45
46 protected:
47  // Constructor that uses an in-memory sqlite database, for testing.
48  DOMStorageDatabase();
49
50 private:
51  friend class LocalStorageDatabaseAdapter;
52  FRIEND_TEST_ALL_PREFIXES(DOMStorageDatabaseTest, SimpleOpenAndClose);
53  FRIEND_TEST_ALL_PREFIXES(DOMStorageDatabaseTest, TestLazyOpenIsLazy);
54  FRIEND_TEST_ALL_PREFIXES(DOMStorageDatabaseTest, TestDetectSchemaVersion);
55  FRIEND_TEST_ALL_PREFIXES(DOMStorageDatabaseTest,
56                           TestLazyOpenUpgradesDatabase);
57  FRIEND_TEST_ALL_PREFIXES(DOMStorageDatabaseTest, SimpleWriteAndReadBack);
58  FRIEND_TEST_ALL_PREFIXES(DOMStorageDatabaseTest, WriteWithClear);
59  FRIEND_TEST_ALL_PREFIXES(DOMStorageDatabaseTest,
60                           UpgradeFromV1ToV2WithData);
61  FRIEND_TEST_ALL_PREFIXES(DOMStorageDatabaseTest, TestSimpleRemoveOneValue);
62  FRIEND_TEST_ALL_PREFIXES(DOMStorageDatabaseTest,
63                           TestCanOpenAndReadWebCoreDatabase);
64  FRIEND_TEST_ALL_PREFIXES(DOMStorageDatabaseTest,
65                           TestCanOpenFileThatIsNotADatabase);
66  FRIEND_TEST_ALL_PREFIXES(DOMStorageAreaTest, BackingDatabaseOpened);
67  FRIEND_TEST_ALL_PREFIXES(DOMStorageAreaTest, CommitTasks);
68  FRIEND_TEST_ALL_PREFIXES(DOMStorageAreaTest, PurgeMemory);
69
70  enum SchemaVersion {
71    INVALID,
72    V1,
73    V2
74  };
75
76  // Open the database at file_path_ if it exists already and creates it if
77  // |create_if_needed| is true.
78  // Ensures we are at the correct database version and creates or updates
79  // tables as necessary. Returns false on failure.
80  bool LazyOpen(bool create_if_needed);
81
82  // Analyses the database to verify that the connection that is open is indeed
83  // a valid database and works out the schema version.
84  SchemaVersion DetectSchemaVersion();
85
86  // Creates the database table at V2. Returns true if the table was created
87  // successfully, false otherwise. Will return false if the table already
88  // exists.
89  bool CreateTableV2();
90
91  // If we have issues while trying to open the file (corrupted databse,
92  // failing to upgrade, that sort of thing) this function will remove
93  // the file from disk and attempt to create a new database from
94  // scratch.
95  bool DeleteFileAndRecreate();
96
97  // Version 1 -> 2 migrates the value column in the ItemTable from a TEXT
98  // to a BLOB. Exisitng data is preserved on success. Returns false if the
99  // upgrade failed. If true is returned, the database is guaranteed to be at
100  // version 2.
101  bool UpgradeVersion1To2();
102
103  void Close();
104  bool IsOpen() const { return db_.get() ? db_->is_open() : false; }
105
106  // Initialization code shared between the two constructors of this class.
107  void Init();
108
109  // Path to the database on disk.
110  const base::FilePath file_path_;
111  scoped_ptr<sql::Connection> db_;
112  bool failed_to_open_;
113  bool tried_to_recreate_;
114  bool known_to_be_empty_;
115};
116
117}  // namespace content
118
119#endif  // CONTENT_BROWSER_DOM_STORAGE_DOM_STORAGE_DATABASE_H_
120