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<?php |
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|
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declare(strict_types=1); |
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|
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namespace malkusch\lock\mutex; |
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|
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use InvalidArgumentException; |
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use malkusch\lock\exception\LockAcquireException; |
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use malkusch\lock\exception\TimeoutException; |
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|
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class MySQLMutex extends LockMutex |
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{ |
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/** |
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* @var \PDO |
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*/ |
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private $pdo; |
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|
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/** |
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* @var string |
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*/ |
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private $name; |
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/** |
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* @var int |
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*/ |
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private $timeout; |
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|
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public function __construct(\PDO $PDO, string $name, int $timeout = 0) |
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{ |
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$this->pdo = $PDO; |
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|
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if (\strlen($name) > 64) { |
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throw new InvalidArgumentException('The maximum length of the lock name is 64 characters.'); |
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} |
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|
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$this->name = $name; |
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$this->timeout = $timeout; |
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} |
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|
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/** |
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* @throws LockAcquireException |
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*/ |
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public function lock(): void |
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{ |
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$statement = $this->pdo->prepare('SELECT GET_LOCK(?,?)'); |
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|
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$statement->execute([ |
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$this->name, |
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$this->timeout, |
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]); |
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|
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$statement->setFetchMode(\PDO::FETCH_NUM); |
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$row = $statement->fetch(); |
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|
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if ($row[0] == 1) { |
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/* |
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* Returns 1 if the lock was obtained successfully. |
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*/ |
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return; |
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} |
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|
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if ($row[0] === null) { |
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/* |
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* NULL if an error occurred (such as running out of memory or the thread was killed with mysqladmin kill). |
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*/ |
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throw new LockAcquireException('An error occurred while acquiring the lock'); |
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} |
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|
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throw TimeoutException::create($this->timeout); |
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} |
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|
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public function unlock(): void |
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{ |
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$statement = $this->pdo->prepare('DO RELEASE_LOCK(?)'); |
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$statement->execute([ |
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$this->name |
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]); |
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} |
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} |
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|
