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// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "base/string_util.h"
#include "chrome/browser/history/archived_database.h"
namespace history {
namespace {
static const int kCurrentVersionNumber = 2;
static const int kCompatibleVersionNumber = 2;
} // namespace
ArchivedDatabase::ArchivedDatabase()
: db_(NULL),
transaction_nesting_(0) {
}
ArchivedDatabase::~ArchivedDatabase() {
}
bool ArchivedDatabase::Init(const std::wstring& file_name) {
// Open the history database, using the narrow version of open indicates to
// sqlite that we want the database to be in UTF-8 if it doesn't already
// exist.
DCHECK(!db_) << "Already initialized!";
if (sqlite3_open(WideToUTF8(file_name).c_str(), &db_) != SQLITE_OK)
return false;
statement_cache_ = new SqliteStatementCache(db_);
DBCloseScoper scoper(&db_, &statement_cache_);
// Set the database page size to something a little larger to give us
// better performance (we're typically seek rather than bandwidth limited).
// This only has an effect before any tables have been created, otherwise
// this is a NOP. Must be a power of 2 and a max of 8192.
sqlite3_exec(db_, "PRAGMA page_size=4096", NULL, NULL, NULL);
// Don't use very much memory caching this database. We seldom use it for
// anything important.
sqlite3_exec(db_, "PRAGMA cache_size=64", NULL, NULL, NULL);
// Run the database in exclusive mode. Nobody else should be accessing the
// database while we're running, and this will give somewhat improved perf.
sqlite3_exec(db_, "PRAGMA locking_mode=EXCLUSIVE", NULL, NULL, NULL);
BeginTransaction();
// Version check.
if (!meta_table_.Init(std::string(), kCurrentVersionNumber,
kCompatibleVersionNumber, db_))
return false;
// Create the tables.
if (!CreateURLTable(false) || !InitVisitTable() ||
!InitKeywordSearchTermsTable())
return false;
CreateMainURLIndex();
if (EnsureCurrentVersion() != INIT_OK)
return false;
// Succeeded: keep the DB open by detaching the auto-closer.
scoper.Detach();
db_closer_.Attach(&db_, &statement_cache_);
CommitTransaction();
return true;
}
void ArchivedDatabase::BeginTransaction() {
DCHECK(db_);
if (transaction_nesting_ == 0) {
int rv = sqlite3_exec(db_, "BEGIN TRANSACTION", NULL, NULL, NULL);
DCHECK(rv == SQLITE_OK) << "Failed to begin transaction";
}
transaction_nesting_++;
}
void ArchivedDatabase::CommitTransaction() {
DCHECK(db_);
DCHECK(transaction_nesting_ > 0) << "Committing too many transactions";
transaction_nesting_--;
if (transaction_nesting_ == 0) {
int rv = sqlite3_exec(db_, "COMMIT", NULL, NULL, NULL);
DCHECK(rv == SQLITE_OK) << "Failed to commit transaction";
}
}
sqlite3* ArchivedDatabase::GetDB() {
return db_;
}
SqliteStatementCache& ArchivedDatabase::GetStatementCache() {
return *statement_cache_;
}
// Migration -------------------------------------------------------------------
InitStatus ArchivedDatabase::EnsureCurrentVersion() {
// We can't read databases newer than we were designed for.
if (meta_table_.GetCompatibleVersionNumber() > kCurrentVersionNumber) {
LOG(WARNING) << "Archived database is too new.";
return INIT_TOO_NEW;
}
// NOTICE: If you are changing structures for things shared with the archived
// history file like URLs, visits, or downloads, that will need migration as
// well. Instead of putting such migration code in this class, it should be
// in the corresponding file (url_database.cc, etc.) and called from here and
// from the archived_database.cc.
int cur_version = meta_table_.GetVersionNumber();
if (cur_version == 1) {
if (!DropStarredIDFromURLs()) {
LOG(WARNING) << "Unable to update archived database to version 2.";
return INIT_FAILURE;
}
++cur_version;
meta_table_.SetVersionNumber(cur_version);
meta_table_.SetCompatibleVersionNumber(
std::min(cur_version, kCompatibleVersionNumber));
}
// Put future migration cases here.
// When the version is too old, we just try to continue anyway, there should
// not be a released product that makes a database too old for us to handle.
LOG_IF(WARNING, cur_version < kCurrentVersionNumber) <<
"Archived database version " << cur_version << " is too old to handle.";
return INIT_OK;
}
} // namespace history
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