1// Copyright (c) 2009 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 "app/sql/transaction.h"
9#include "base/string_util.h"
10#include "chrome/browser/history/archived_database.h"
11
12namespace history {
13
14namespace {
15
16static const int kCurrentVersionNumber = 3;
17static const int kCompatibleVersionNumber = 2;
18
19}  // namespace
20
21ArchivedDatabase::ArchivedDatabase() {
22}
23
24ArchivedDatabase::~ArchivedDatabase() {
25}
26
27bool ArchivedDatabase::Init(const 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  sql::Transaction transaction(&db_);
46  if (!transaction.Begin()) {
47    db_.Close();
48    return false;
49  }
50
51  // Version check.
52  if (!meta_table_.Init(&db_, kCurrentVersionNumber,
53                        kCompatibleVersionNumber)) {
54    db_.Close();
55    return false;
56  }
57
58  // Create the tables.
59  if (!CreateURLTable(false) || !InitVisitTable() ||
60      !InitKeywordSearchTermsTable()) {
61    db_.Close();
62    return false;
63  }
64  CreateMainURLIndex();
65  CreateKeywordSearchTermsIndices();
66
67  if (EnsureCurrentVersion() != sql::INIT_OK) {
68    db_.Close();
69    return false;
70  }
71
72  return transaction.Commit();
73}
74
75void ArchivedDatabase::BeginTransaction() {
76  db_.BeginTransaction();
77}
78
79void ArchivedDatabase::CommitTransaction() {
80  db_.CommitTransaction();
81}
82
83sql::Connection& ArchivedDatabase::GetDB() {
84  return db_;
85}
86
87// Migration -------------------------------------------------------------------
88
89sql::InitStatus ArchivedDatabase::EnsureCurrentVersion() {
90  // We can't read databases newer than we were designed for.
91  if (meta_table_.GetCompatibleVersionNumber() > kCurrentVersionNumber) {
92    LOG(WARNING) << "Archived database is too new.";
93    return sql::INIT_TOO_NEW;
94  }
95
96  // NOTICE: If you are changing structures for things shared with the archived
97  // history file like URLs, visits, or downloads, that will need migration as
98  // well. Instead of putting such migration code in this class, it should be
99  // in the corresponding file (url_database.cc, etc.) and called from here and
100  // from the archived_database.cc.
101
102  int cur_version = meta_table_.GetVersionNumber();
103  if (cur_version == 1) {
104    if (!DropStarredIDFromURLs()) {
105      LOG(WARNING) << "Unable to update archived database to version 2.";
106      return sql::INIT_FAILURE;
107    }
108    ++cur_version;
109    meta_table_.SetVersionNumber(cur_version);
110    meta_table_.SetCompatibleVersionNumber(
111        std::min(cur_version, kCompatibleVersionNumber));
112  }
113
114  if (cur_version == 2) {
115    // This is the version prior to adding visit_source table.
116    ++cur_version;
117    meta_table_.SetVersionNumber(cur_version);
118  }
119
120  // Put future migration cases here.
121
122  // When the version is too old, we just try to continue anyway, there should
123  // not be a released product that makes a database too old for us to handle.
124  LOG_IF(WARNING, cur_version < kCurrentVersionNumber) <<
125      "Archived database version " << cur_version << " is too old to handle.";
126
127  return sql::INIT_OK;
128}
129}  // namespace history
130