1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
|
// Copyright 2008, Google Inc.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#ifndef CHROME_BROWSER_META_TABLE_HELPER_H__
#define CHROME_BROWSER_META_TABLE_HELPER_H__
#include <string>
#include "base/basictypes.h"
struct sqlite3;
class SQLStatement;
// MetaTableHelper maintains arbitrary key/value pairs in a table, as well
// as version information. MetaTableHelper is used by both WebDatabase and
// HistoryDatabase to maintain version information.
//
// To use a MetalTableHelper you must invoke the init method specifying the
// database to use.
class MetaTableHelper {
public:
// Creates a new MetaTableHelper. After construction you must invoke
// Init with the appropriate database.
MetaTableHelper();
~MetaTableHelper();
// Initializes the MetaTableHelper, creating the meta table if necessary. For
// new tables, it will initialize the version number to |version| and will
// set the optional |is_new| out var to true.
//
// The name of the database in the sqlite connection (for tables named with
// the "db_name.table_name" scheme is given in |db_name|. If empty, it is
// assumed there is no database name.
bool Init(const std::string& db_name, int version, sqlite3* db);
// Version number. This should be the version number of the creator of the
// file. GetVersionNumber will return 0 if there is no version number.
// See also *CompatibleVersionNumber.
void SetVersionNumber(int version);
int GetVersionNumber();
// The compatible version number is the lowest version that this file format
// is readable by. If an addition or other non-critical change is made to the
// file in such a way that it could be read or written non-catastrophically
// by an older version, this number tells us which version that is.
//
// Any version newer than this should be able to interpret the file. Any
// version older than this should not touch the file or else it might
// corrupt it.
//
// GetCompatibleVersionNumber will return 0 if there is none.
void SetCompatibleVersionNumber(int version);
int GetCompatibleVersionNumber();
// Arbitrary key/value pair with a wstring value.
bool SetValue(const std::string& key, const std::wstring& value);
bool GetValue(const std::string& key, std::wstring* value);
// Arbitrary key/value pair with an int value.
bool SetValue(const std::string& key, int value);
bool GetValue(const std::string& key, int* value);
// Arbitrary key/value pair with an int64 value.
bool SetValue(const std::string& key, int64 value);
bool GetValue(const std::string& key, int64* value);
private:
// Conveniences to prepare the two types of statements used by
// MetaTableHelper.
bool PrepareSetStatement(SQLStatement* statement, const std::string& key);
bool PrepareGetStatement(SQLStatement* statement, const std::string& key);
sqlite3* db_;
// Name of the database within the connection, if there is one. When empty,
// there is no special database name.
std::string db_name_;
DISALLOW_EVIL_CONSTRUCTORS(MetaTableHelper);
};
#endif // CHROME_BROWSER_META_TABLE_HELPER_H__
|
