nextcloud/lib/private/DB/AdapterSqlite.php

101 lines
3.8 KiB
PHP

<?php
/**
* @copyright Copyright (c) 2016, ownCloud, Inc.
*
* @author Bart Visscher <bartv@thisnet.nl>
* @author Christoph Wurst <christoph@winzerhof-wurst.at>
* @author Joas Schilling <coding@schilljs.com>
* @author Morris Jobke <hey@morrisjobke.de>
* @author Robin Appelman <robin@icewind.nl>
* @author Thomas Müller <thomas.mueller@tmit.eu>
*
* @license AGPL-3.0
*
* This code is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, version 3,
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License, version 3,
* along with this program. If not, see <http://www.gnu.org/licenses/>
*
*/
namespace OC\DB;
use Doctrine\DBAL\Exception\UniqueConstraintViolationException;
class AdapterSqlite extends Adapter {
/**
* @param string $tableName
*/
public function lockTable($tableName) {
$this->conn->executeUpdate('BEGIN EXCLUSIVE TRANSACTION');
}
public function unlockTable() {
$this->conn->executeUpdate('COMMIT TRANSACTION');
}
public function fixupStatement($statement) {
$statement = preg_replace('/`(\w+)` ILIKE \?/', 'LOWER($1) LIKE LOWER(?)', $statement);
$statement = str_replace('`', '"', $statement);
$statement = str_ireplace('NOW()', 'datetime(\'now\')', $statement);
$statement = str_ireplace('GREATEST(', 'MAX(', $statement);
$statement = str_ireplace('UNIX_TIMESTAMP()', 'strftime(\'%s\',\'now\')', $statement);
return $statement;
}
/**
* Insert a row if the matching row does not exists. To accomplish proper race condition avoidance
* it is needed that there is also a unique constraint on the values. Then this method will
* catch the exception and return 0.
*
* @param string $table The table name (will replace *PREFIX* with the actual prefix)
* @param array $input data that should be inserted into the table (column name => value)
* @param array|null $compare List of values that should be checked for "if not exists"
* If this is null or an empty array, all keys of $input will be compared
* Please note: text fields (clob) must not be used in the compare array
* @return int number of inserted rows
* @throws \Doctrine\DBAL\DBALException
* @deprecated 15.0.0 - use unique index and "try { $db->insert() } catch (UniqueConstraintViolationException $e) {}" instead, because it is more reliable and does not have the risk for deadlocks - see https://github.com/nextcloud/server/pull/12371
*/
public function insertIfNotExist($table, $input, array $compare = null) {
if (empty($compare)) {
$compare = array_keys($input);
}
$fieldList = '`' . implode('`,`', array_keys($input)) . '`';
$query = "INSERT INTO `$table` ($fieldList) SELECT "
. str_repeat('?,', count($input) - 1).'? '
. " WHERE NOT EXISTS (SELECT 1 FROM `$table` WHERE ";
$inserts = array_values($input);
foreach ($compare as $key) {
$query .= '`' . $key . '`';
if (is_null($input[$key])) {
$query .= ' IS NULL AND ';
} else {
$inserts[] = $input[$key];
$query .= ' = ? AND ';
}
}
$query = substr($query, 0, -5);
$query .= ')';
try {
return $this->conn->executeUpdate($query, $inserts);
} catch (UniqueConstraintViolationException $e) {
// if this is thrown then a concurrent insert happened between the insert and the sub-select in the insert, that should have avoided it
// it's fine to ignore this then
//
// more discussions about this can be found at https://github.com/nextcloud/server/pull/12315
return 0;
}
}
}