framework/mutex/MysqlMutex.php
<?php
/**
* @link https://www.yiiframework.com/
* @copyright Copyright (c) 2008 Yii Software LLC
* @license https://www.yiiframework.com/license/
*/
namespace yii\mutex;
use yii\base\InvalidConfigException;
use yii\db\Expression;
/**
* MysqlMutex implements mutex "lock" mechanism via MySQL locks.
*
* Application configuration example:
*
* ```
* [
* 'components' => [
* 'db' => [
* 'class' => 'yii\db\Connection',
* 'dsn' => 'mysql:host=127.0.0.1;dbname=demo',
* ]
* 'mutex' => [
* 'class' => 'yii\mutex\MysqlMutex',
* ],
* ],
* ]
* ```
*
* @see Mutex
*
* @author resurtm <resurtm@gmail.com>
* @since 2.0
*/
class MysqlMutex extends DbMutex
{
/**
* @var Expression|string|null prefix value. If null (by default) then connection's current database name is used.
* @since 2.0.47
*/
public $keyPrefix = null;
/**
* Initializes MySQL specific mutex component implementation.
* @throws InvalidConfigException if [[db]] is not MySQL connection.
*/
public function init()
{
parent::init();
if ($this->db->driverName !== 'mysql') {
throw new InvalidConfigException('In order to use MysqlMutex connection must be configured to use MySQL database.');
}
if ($this->keyPrefix === null) {
$this->keyPrefix = new Expression('DATABASE()');
}
}
/**
* Acquires lock by given name.
* @param string $name of the lock to be acquired.
* @param int $timeout time (in seconds) to wait for lock to become released.
* @return bool acquiring result.
* @see https://dev.mysql.com/doc/refman/8.0/en/miscellaneous-functions.html#function_get-lock
*/
protected function acquireLock($name, $timeout = 0)
{
return $this->db->useMaster(function ($db) use ($name, $timeout) {
/** @var \yii\db\Connection $db */
$nameData = $this->prepareName();
return (bool)$db->createCommand(
'SELECT GET_LOCK(' . $nameData[0] . ', :timeout), :prefix',
array_merge(
[':name' => $this->hashLockName($name), ':timeout' => $timeout, ':prefix' => $this->keyPrefix],
$nameData[1]
)
)->queryScalar();
});
}
/**
* Releases lock by given name.
* @param string $name of the lock to be released.
* @return bool release result.
* @see https://dev.mysql.com/doc/refman/8.0/en/miscellaneous-functions.html#function_release-lock
*/
protected function releaseLock($name)
{
return $this->db->useMaster(function ($db) use ($name) {
/** @var \yii\db\Connection $db */
$nameData = $this->prepareName();
return (bool)$db->createCommand(
'SELECT RELEASE_LOCK(' . $nameData[0] . '), :prefix',
array_merge(
[':name' => $this->hashLockName($name), ':prefix' => $this->keyPrefix],
$nameData[1]
)
)->queryScalar();
});
}
/**
* Prepare lock name
* @return array expression and params
* @since 2.0.48
*/
protected function prepareName()
{
$params = [];
$expression = 'SUBSTRING(CONCAT(:prefix, :name), 1, 64)';
if ($this->keyPrefix instanceof Expression) {
$expression = strtr($expression, [':prefix' => $this->keyPrefix->expression]);
$params = $this->keyPrefix->params;
}
return [$expression, $params];
}
/**
* Generate hash for lock name to avoid exceeding lock name length limit.
*
* @param string $name
* @return string
* @since 2.0.16
* @see https://github.com/yiisoft/yii2/pull/16836
*/
protected function hashLockName($name)
{
return sha1($name);
}
}