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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 #include "chrome/browser/webdata/web_database.h" | |
6 | |
7 #include <algorithm> | |
8 | |
9 #include "base/stl_util.h" | |
10 #include "content/public/browser/notification_service.h" | |
11 #include "sql/statement.h" | |
12 #include "sql/transaction.h" | |
13 | |
14 // Current version number. Note: when changing the current version number, | |
15 // corresponding changes must happen in the unit tests, and new migration test | |
16 // added. See |WebDatabaseMigrationTest::kCurrentTestedVersionNumber|. | |
17 // static | |
18 const int WebDatabase::kCurrentVersionNumber = 49; | |
19 | |
20 namespace { | |
21 | |
22 const int kCompatibleVersionNumber = 48; | |
23 | |
24 // Change the version number and possibly the compatibility version of | |
25 // |meta_table_|. | |
26 void ChangeVersion(sql::MetaTable* meta_table, | |
27 int version_num, | |
28 bool update_compatible_version_num) { | |
29 meta_table->SetVersionNumber(version_num); | |
30 if (update_compatible_version_num) { | |
31 meta_table->SetCompatibleVersionNumber( | |
32 std::min(version_num, kCompatibleVersionNumber)); | |
33 } | |
34 } | |
35 | |
36 // Outputs the failed version number as a warning and always returns | |
37 // |sql::INIT_FAILURE|. | |
38 sql::InitStatus FailedMigrationTo(int version_num) { | |
39 LOG(WARNING) << "Unable to update web database to version " | |
40 << version_num << "."; | |
41 NOTREACHED(); | |
42 return sql::INIT_FAILURE; | |
43 } | |
44 | |
45 } // namespace | |
46 | |
47 WebDatabase::WebDatabase() {} | |
48 | |
49 WebDatabase::~WebDatabase() { | |
50 } | |
51 | |
52 void WebDatabase::AddTable(WebDatabaseTable* table) { | |
53 tables_[table->GetTypeKey()] = table; | |
54 } | |
55 | |
56 WebDatabaseTable* WebDatabase::GetTable(WebDatabaseTable::TypeKey key) { | |
57 return tables_[key]; | |
58 } | |
59 | |
60 void WebDatabase::BeginTransaction() { | |
61 db_.BeginTransaction(); | |
62 } | |
63 | |
64 void WebDatabase::CommitTransaction() { | |
65 db_.CommitTransaction(); | |
66 } | |
67 | |
68 sql::Connection* WebDatabase::GetSQLConnection() { | |
69 return &db_; | |
70 } | |
71 | |
72 sql::InitStatus WebDatabase::Init(const base::FilePath& db_name) { | |
73 // When running in unit tests, there is already a NotificationService object. | |
74 // Since only one can exist at a time per thread, check first. | |
75 if (!content::NotificationService::current()) | |
76 notification_service_.reset(content::NotificationService::Create()); | |
77 | |
78 db_.set_error_histogram_name("Sqlite.Web.Error"); | |
79 | |
80 // We don't store that much data in the tables so use a small page size. | |
81 // This provides a large benefit for empty tables (which is very likely with | |
82 // the tables we create). | |
83 db_.set_page_size(2048); | |
84 | |
85 // We shouldn't have much data and what access we currently have is quite | |
86 // infrequent. So we go with a small cache size. | |
87 db_.set_cache_size(32); | |
88 | |
89 // Run the database in exclusive mode. Nobody else should be accessing the | |
90 // database while we're running, and this will give somewhat improved perf. | |
91 db_.set_exclusive_locking(); | |
92 | |
93 if (!db_.Open(db_name)) | |
94 return sql::INIT_FAILURE; | |
95 | |
96 // Initialize various tables | |
97 sql::Transaction transaction(&db_); | |
98 if (!transaction.Begin()) | |
99 return sql::INIT_FAILURE; | |
100 | |
101 // Version check. | |
102 if (!meta_table_.Init(&db_, kCurrentVersionNumber, kCompatibleVersionNumber)) | |
103 return sql::INIT_FAILURE; | |
104 if (meta_table_.GetCompatibleVersionNumber() > kCurrentVersionNumber) { | |
105 LOG(WARNING) << "Web database is too new."; | |
106 return sql::INIT_TOO_NEW; | |
107 } | |
108 | |
109 // Initialize the tables. | |
110 for (TableMap::iterator it = tables_.begin(); | |
111 it != tables_.end(); | |
112 ++it) { | |
113 if (!it->second->Init(&db_, &meta_table_)) { | |
114 LOG(WARNING) << "Unable to initialize the web database."; | |
115 return sql::INIT_FAILURE; | |
116 } | |
117 } | |
118 | |
119 // If the file on disk is an older database version, bring it up to date. | |
120 // If the migration fails we return an error to caller and do not commit | |
121 // the migration. | |
122 sql::InitStatus migration_status = MigrateOldVersionsAsNeeded(); | |
123 if (migration_status != sql::INIT_OK) | |
124 return migration_status; | |
125 | |
126 return transaction.Commit() ? sql::INIT_OK : sql::INIT_FAILURE; | |
127 } | |
128 | |
129 sql::InitStatus WebDatabase::MigrateOldVersionsAsNeeded() { | |
130 // Some malware used to lower the version number, causing migration to | |
131 // fail. Ensure the version number is at least as high as the compatible | |
132 // version number. | |
133 int current_version = std::max(meta_table_.GetVersionNumber(), | |
134 meta_table_.GetCompatibleVersionNumber()); | |
135 if (current_version > meta_table_.GetVersionNumber()) | |
136 ChangeVersion(&meta_table_, current_version, false); | |
137 | |
138 if (current_version < 20) { | |
139 // Versions 1 - 19 are unhandled. Version numbers greater than | |
140 // kCurrentVersionNumber should have already been weeded out by the caller. | |
141 // | |
142 // When the version is too old, we return failure error code. The schema | |
143 // is too out of date to migrate. | |
144 // | |
145 // There should not be a released product that makes a database too old to | |
146 // migrate. If we do encounter such a legacy database, we will need a | |
147 // better solution to handle it (i.e., pop up a dialog to tell the user, | |
148 // erase all their prefs and start over, etc.). | |
149 LOG(WARNING) << "Web database version " << current_version << | |
150 " is too old to handle."; | |
151 NOTREACHED(); | |
152 return sql::INIT_FAILURE; | |
153 } | |
154 | |
155 for (int next_version = current_version + 1; | |
156 next_version <= kCurrentVersionNumber; | |
157 ++next_version) { | |
158 // Give each table a chance to migrate to this version. | |
159 for (TableMap::iterator it = tables_.begin(); | |
160 it != tables_.end(); | |
161 ++it) { | |
162 // Any of the tables may set this to true, but by default it is false. | |
163 bool update_compatible_version = false; | |
164 if (!it->second->MigrateToVersion(next_version, | |
165 &update_compatible_version)) { | |
166 return FailedMigrationTo(next_version); | |
167 } | |
168 | |
169 ChangeVersion(&meta_table_, next_version, update_compatible_version); | |
170 } | |
171 } | |
172 return sql::INIT_OK; | |
173 } | |
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