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doctrine-dbal
Commit 224b76e1 authored by Tobias Schultze's avatar Tobias Schultze
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remove the retry logic which can be provided by another package

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lib/Doctrine/DBAL/RetryWrapper.php deleted 100644 → 0
View file @ af90b420
<?php
/*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* This software consists of voluntary contributions made by many individuals
* and is licensed under the MIT license. For more information, see
* <http://www.doctrine-project.org>.
*/
namespace Doctrine\DBAL;
use Doctrine\DBAL\Exception\RetryableException;
/**
* Wraps a database operation, represented as a callable, in retry logic.
*
* It is best practice to retry transactions that are aborted because of deadlocks
* or timeouts. Such errors are caused by lock contention and you often can design
* your application to reduce the likeliness that such an error occurs. But it's
* impossible to guarantee that such error conditions will never occur. So when you
* have to ensure the application does not fail in edge cases or high load, retrying
* transactions in case of such errors is actually a must.
*
* The class implements the retry logic for you by re-executing your callable in
* case of temporary database errors where retrying the failed transaction after a
* short delay usually resolves the problem. Just wrap your database transaction
* or single query in this class and invoke it. You can also pass arguments when
* invoking the wrapper which will be passed through to the underlying callable.
*
* @author Tobias Schultze <http://tobion.de>
* @link www.doctrine-project.org
* @since 2.6
*/
class RetryWrapper
{
/**
* The database operation to execute that can be retried on failure.
*
* @var callable
*/
private $callable;
/**
* Maximum number of retries.
*
* @var integer
*/
private $maxRetries;
/**
* Delay between retries in milliseconds.
*
* @var integer
*/
private $retryDelay;
/**
* Actual number of retries.
*
* @var integer|null
*/
private $retries;
/**
* Constructor to wrap a callable.
*
* @param callable $callable The database operation to execute that can be retried on failure.
* @param integer $maxRetries Maximum number of retries.
* @param integer $retryDelay Delay between retries in milliseconds to give the blocking
* transaction time to finish.
*/
public function __construct($callable, $maxRetries = 3, $retryDelay = 100)
{
$this->callable = $callable;
$this->maxRetries = $maxRetries;
$this->retryDelay = $retryDelay;
}
/**
* Returns the number of retries used.
*
* @return integer|null The number of retries used or null if wrapper has not been invoked yet
*/
public function getRetries()
{
return $this->retries;
}
/**
* Executes the callable and retries it in case of a temporary database error.
*
* The callable is only re-executed for temporary database errors where retrying
* the failed transaction after a short delay usually resolves the problem. Such
* errors are for example deadlocks and lock wait timeouts. Internally the raised
* exception must implement the marker interface RetryableException. Other exceptions
* like syntax errors or constraint violations will not cause the callable to be
* re-executed.
*
* All arguments given will be passed through to the wrapped callable.
*
* @return mixed The return value of the wrapped callable
*
* @throws \Exception If an exception has been raised where retrying makes no sense
* or a RetryableException after max retries has been reached.
*/
public function __invoke()
{
$this->retries = 0;
$args = func_get_args();
do {
try {
return call_user_func_array($this->callable, $args);
} catch (RetryableException $e) {
if ($this->retries < $this->maxRetries) {
$this->retries++;
usleep($this->retryDelay * 1000);
} else {
throw $e;
}
}
} while (true);
}
}
tests/Doctrine/Tests/DBAL/RetryWrapperTest.php deleted 100644 → 0
View file @ af90b420
<?php
namespace Doctrine\Tests\DBAL;
use Doctrine\DBAL\DBALException;
use Doctrine\DBAL\Driver\DriverException;
use Doctrine\DBAL\Exception\DeadlockException;
use Doctrine\DBAL\Exception\RetryableException;
use Doctrine\DBAL\RetryWrapper;
class RetryWrapperTest extends \Doctrine\Tests\DbalTestCase
{
public function testConstructor()
{
$retryWrapper = new RetryWrapper($this->getRetryCallable());
$this->assertNull($retryWrapper->getRetries());
}
public function testWithoutRetry()
{
$retryWrapper = new RetryWrapper($this->getRetryCallable(0));
$this->assertSame('return-value', $retryWrapper());
$this->assertSame(0, $retryWrapper->getRetries());
}
public function testExecuteOnceWithZeroMaxRetries()
{
$retryWrapper = new RetryWrapper($this->getRetryCallable(0), 0);
$this->assertSame('return-value', $retryWrapper(), 'Callable must be executed when max retries is 0');
$this->assertSame(0, $retryWrapper->getRetries());
}
public function testExecuteOnceWithNegativeMaxRetries()
{
$retryWrapper = new RetryWrapper($this->getRetryCallable(0), -3);
$this->assertSame('return-value', $retryWrapper(), 'Callable must be executed when max retries is negative');
$this->assertSame(0, $retryWrapper->getRetries());
}
public function testRetrySucceedsWithDefaultMaxRetries()
{
$retryWrapper = new RetryWrapper($this->getRetryCallable(2));
$this->assertSame('return-value', $retryWrapper());
$this->assertSame(2, $retryWrapper->getRetries());
}
public function testRetryFailsAfterMaxRetries()
{
$retryWrapper = new RetryWrapper($this->getRetryCallable(2), 1);
try {
$retryWrapper();
$this->fail('Wrapper should rethrow exception when max retries has been reached.');
} catch (RetryableException $e) {
$this->assertSame('Deadlock', $e->getMessage());
$this->assertSame(1, $retryWrapper->getRetries());
}
}
public function testNoRetryOnGenericError()
{
$retryWrapper = new RetryWrapper(array(new RetryCallableExample(), 'retryableErrorFollowedByGenericError'), 5);
try {
$retryWrapper();
$this->fail('Wrapper should rethrow exception when not retryable.');
} catch (DBALException $e) {
$this->assertSame('Constraint violation', $e->getMessage());
$this->assertSame(1, $retryWrapper->getRetries(), 'One retry, then abort');
}
}
public function testInvokeWithParams()
{
$retryWrapper = new RetryWrapper(__NAMESPACE__ . '\RetryCallableExample::staticMethodWithParams');
$this->assertSame('foobar', $retryWrapper('foo', 'bar'));
}
private function getRetryCallable($succeedAfterCalls = 0)
{
$callableObject = new RetryCallableExample($succeedAfterCalls);
return array($callableObject, 'succeedAsConfigured');
}
}
class RetryCallableExample
{
private $succeedAfterCalls;
private $executionCount = 0;
public function __construct($succeedAfterCalls = 0)
{
$this->succeedAfterCalls = $succeedAfterCalls;
}
public function succeedAsConfigured()
{
$this->executionCount++;
if ($this->executionCount > $this->succeedAfterCalls) {
return 'return-value';
}
throw new DeadlockException(
'Deadlock',
new DummyDriverException()
);
}
public function retryableErrorFollowedByGenericError()
{
$this->executionCount++;
if ($this->executionCount > 1) {
throw new DBALException(
'Constraint violation'
);
}
throw new DeadlockException(
'Deadlock',
new DummyDriverException()
);
}
public static function staticMethodWithParams($param1, $param2)
{
return $param1 . $param2;
}
}
class DummyDriverException extends \Exception implements DriverException
{
public function getErrorCode()
{
return 'code';
}
public function getSQLState()
{
return 'state';
}
}
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