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 <algorithm>
6 #include <string>
7
8 #include "base/strings/string_util.h"
9 #include "chrome/browser/history/archived_database.h"
10 #include "sql/transaction.h"
11
12 namespace history {
13
14 namespace {
15
16 static const int kCurrentVersionNumber = 4;
17 static const int kCompatibleVersionNumber = 2;
18
19 } // namespace
20
ArchivedDatabase()21 ArchivedDatabase::ArchivedDatabase() {
22 }
23
~ArchivedDatabase()24 ArchivedDatabase::~ArchivedDatabase() {
25 }
26
Init(const base::FilePath & file_name)27 bool ArchivedDatabase::Init(const base::FilePath& file_name) {
28 // Set the database page size to something a little larger to give us
29 // better performance (we're typically seek rather than bandwidth limited).
30 // This only has an effect before any tables have been created, otherwise
31 // this is a NOP. Must be a power of 2 and a max of 8192.
32 db_.set_page_size(4096);
33
34 // Don't use very much memory caching this database. We seldom use it for
35 // anything important.
36 db_.set_cache_size(64);
37
38 // Run the database in exclusive mode. Nobody else should be accessing the
39 // database while we're running, and this will give somewhat improved perf.
40 db_.set_exclusive_locking();
41
42 if (!db_.Open(file_name))
43 return false;
44
45 if (!InitTables()) {
46 db_.Close();
47 return false;
48 }
49
50 return true;
51 }
52
InitTables()53 bool ArchivedDatabase::InitTables() {
54 sql::Transaction transaction(&db_);
55 if (!transaction.Begin())
56 return false;
57
58 // Version check.
59 if (!meta_table_.Init(&db_, kCurrentVersionNumber,
60 kCompatibleVersionNumber))
61 return false;
62
63 // Create the tables.
64 if (!CreateURLTable(false) || !InitVisitTable() ||
65 !InitKeywordSearchTermsTable())
66 return false;
67
68 CreateMainURLIndex();
69 CreateKeywordSearchTermsIndices();
70
71 if (EnsureCurrentVersion() != sql::INIT_OK)
72 return false;
73
74 return transaction.Commit();
75 }
76
TrimMemory(bool aggressively)77 void ArchivedDatabase::TrimMemory(bool aggressively) {
78 db_.TrimMemory(aggressively);
79 }
80
BeginTransaction()81 void ArchivedDatabase::BeginTransaction() {
82 db_.BeginTransaction();
83 }
84
CommitTransaction()85 void ArchivedDatabase::CommitTransaction() {
86 db_.CommitTransaction();
87 }
88
GetDB()89 sql::Connection& ArchivedDatabase::GetDB() {
90 return db_;
91 }
92
93 // static
GetCurrentVersion()94 int ArchivedDatabase::GetCurrentVersion() {
95 return kCurrentVersionNumber;
96 }
97
98 // Migration -------------------------------------------------------------------
99
EnsureCurrentVersion()100 sql::InitStatus ArchivedDatabase::EnsureCurrentVersion() {
101 // We can't read databases newer than we were designed for.
102 if (meta_table_.GetCompatibleVersionNumber() > kCurrentVersionNumber) {
103 LOG(WARNING) << "Archived database is too new.";
104 return sql::INIT_TOO_NEW;
105 }
106
107 // NOTICE: If you are changing structures for things shared with the archived
108 // history file like URLs, visits, or downloads, that will need migration as
109 // well. Instead of putting such migration code in this class, it should be
110 // in the corresponding file (url_database.cc, etc.) and called from here and
111 // from the archived_database.cc.
112
113 int cur_version = meta_table_.GetVersionNumber();
114 if (cur_version == 1) {
115 if (!DropStarredIDFromURLs()) {
116 LOG(WARNING) << "Unable to update archived database to version 2.";
117 return sql::INIT_FAILURE;
118 }
119 ++cur_version;
120 meta_table_.SetVersionNumber(cur_version);
121 meta_table_.SetCompatibleVersionNumber(
122 std::min(cur_version, kCompatibleVersionNumber));
123 }
124
125 if (cur_version == 2) {
126 // This is the version prior to adding visit_source table.
127 ++cur_version;
128 meta_table_.SetVersionNumber(cur_version);
129 }
130
131 if (cur_version == 3) {
132 // This is the version prior to adding the visit_duration field in visits
133 // database. We need to migrate the database.
134 if (!MigrateVisitsWithoutDuration()) {
135 LOG(WARNING) << "Unable to update archived database to version 4.";
136 return sql::INIT_FAILURE;
137 }
138 ++cur_version;
139 meta_table_.SetVersionNumber(cur_version);
140 }
141
142 // Put future migration cases here.
143
144 // When the version is too old, we just try to continue anyway, there should
145 // not be a released product that makes a database too old for us to handle.
146 LOG_IF(WARNING, cur_version < kCurrentVersionNumber) <<
147 "Archived database version " << cur_version << " is too old to handle.";
148
149 return sql::INIT_OK;
150 }
151 } // namespace history
152