symfony · alexander-schranz · Dec 12, 2024 · Dec 12, 2024 · Dec 12, 2024 · Dec 12, 2024
diff --git a/src/Symfony/Component/Semaphore/Exception/UnserializableKeyException.php b/src/Symfony/Component/Semaphore/Exception/UnserializableKeyException.php
@@ -0,0 +1,25 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Semaphore\Exception;
+
+use Symfony\Component\Lock\Exception\ExceptionInterface;
+
+/**
+ * UnserializableKeyException is thrown when the key contains state that can no
+ * be serialized and the user try to serialize it.
+ * ie. Semaphore with lock states, ...
+ *
+ * @author Alexander Schranz <alexander@sulu.io>
+ */
+class UnserializableKeyException extends \RuntimeException implements ExceptionInterface
+{
+}
diff --git a/src/Symfony/Component/Semaphore/Key.php b/src/Symfony/Component/Semaphore/Key.php
@@ -12,6 +12,7 @@
 namespace Symfony\Component\Semaphore;
 
 use Symfony\Component\Semaphore\Exception\InvalidArgumentException;
+use Symfony\Component\Semaphore\Exception\UnserializableKeyException;
 
 /**
  * Key is a container for the state of the semaphores in stores.
@@ -23,6 +24,7 @@ final class Key
 {
     private ?float $expiringTime = null;
     private array $state = [];
+    private bool $serializable = true;
 
     public function __construct(
         private string $resource,
@@ -101,4 +103,18 @@ public function isExpired(): bool
     {
         return null !== $this->expiringTime && $this->expiringTime <= microtime(true);
     }
+
+    public function markUnserializable(): void
+    {
+        $this->serializable = false;
+    }
+
+    public function __sleep(): array
+    {
+        if (!$this->serializable) {
+            throw new UnserializableKeyException('The key cannot be serialized.');
+        }
+
+        return ['resource', 'expiringTime', 'state'];
+    }
 }
diff --git a/src/Symfony/Component/Semaphore/Store/LockStore.php b/src/Symfony/Component/Semaphore/Store/LockStore.php
@@ -0,0 +1,171 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Semaphore\Store;
+
+use Symfony\Component\Lock\Exception\LockReleasingException;
+use Symfony\Component\Lock\LockFactory;
+use Symfony\Component\Lock\LockInterface;
+use Symfony\Component\Semaphore\Exception\SemaphoreAcquiringException;
+use Symfony\Component\Semaphore\Exception\SemaphoreExpiredException;
+use Symfony\Component\Semaphore\Key;
+use Symfony\Component\Semaphore\PersistingStoreInterface;
+
+/**
+ * @author Alexander Schranz <alexander@sulu.io>
+ */
+final class LockStore implements PersistingStoreInterface
+{
+    public function __construct(
+        private readonly LockFactory $lockFactory,
+    ) {
+    }
+
+    public function save(Key $key, float $ttlInSecond): void
+    {
+        $locks = $this->getExistingLocks($key);
+
+        if ([] !== $locks) {
+            return;
+        }
+
+        $locks = $this->createLocks($key, $ttlInSecond);
+
+        $key->setState(__CLASS__, $locks);
+        $key->markUnserializable();
+    }
+
+    public function delete(Key $key): void
+    {
+        $this->releaseLocks($this->getExistingLocks($key), $key);
+    }
+
+    public function exists(Key $key): bool
+    {
+        $locks = $this->getExistingLocks($key);
+
+        if (\count($locks) >= $key->getWeight()) {
+            return true;
+        }
+
+        $this->releaseLocks($locks, $key);
+
+        return false;
+    }
+
+    public function putOffExpiration(Key $key, float $ttlInSecond): void
+    {
+        $locks = $this->getExistingLocks($key);
+        foreach ($locks as $lock) {
+            if ($lock->isExpired()) {
+                $this->releaseLocks($locks, $key);
+
+                throw new SemaphoreExpiredException($key, 'One or multiple locks are already expired.');
+            }
+
+            $lock->refresh($ttlInSecond);
+        }
+
+        if (\count($locks) !== $key->getWeight()) {
+            $this->releaseLocks($locks, $key);
+
+            throw new SemaphoreExpiredException($key, 'One or multiple locks were not even acquired.');
+        }
+    }
+
+    /**
+     * @param array<LockInterface> $locks
+     */
+    private function releaseLocks(array $locks, Key $key): void
+    {
+        $lockReleasingException = null;
+        foreach ($locks as $lock) {
+            try {
+                $lock->release();
+            } catch (LockReleasingException $e) { // we still need to release all other locks before throw the exception
+                $lockReleasingException ??= $e;
+            }
+        }
+
+        if (null !== $lockReleasingException) {
+            throw $lockReleasingException;
+        }
+
+        $key->setState(__CLASS__, null);
+    }
+
+    /**
+     * @return array<LockInterface>
+     */
+    private function getExistingLocks(Key $key): array
+    {
+        if ($key->hasState(__CLASS__)) {
+            return $key->getState(__CLASS__);
+        }
+
+        return [];
+    }
+
+    /**
+     * @return array<LockInterface>
+     */
+    private function createLocks(Key $key, float $ttlInSecond): array
+    {
+        $locks = [];
+        $lockName = $key->__toString();
+        $limit = $key->getLimit();
+
+        // use a random start point to have a higher chance to catch a free slot directly
+        $startPoint = rand(0, $limit - 1);
+
+        $previousException = null;
+        try {
+            for ($i = 0; $i < $limit; ++$i) {
+                $index = ($startPoint + $i) % $limit;
+
+                $lock = $this->lockFactory->createLock($lockName.'_'.$index, $ttlInSecond, false);
+                if ($lock->acquire(false)) { // use lock if we can acquire it else try to catch next lock
+                    $locks[] = $lock;
+
+                    if (\count($locks) >= $key->getWeight()) {
+                        break;
+                    }
+
+                    continue;
+                }
+
+                $acquired = \count($locks);
+                $required = $key->getWeight();
+                $remaining = $key->getLimit() - $i;
+                if (($acquired + $remaining) < $required) { // no chance to get enough locks
+                    break;
+                }
+            }
+        } catch (\Throwable $e) {
+            $previousException = $e;
+        }
+
+        if (\count($locks) !== $key->getWeight()) {
+            try {
+                // release already acquired locks because not got the amount of locks which were required
+                $this->releaseLocks($locks, $key);
+            } catch (\Throwable $e) {
+                // we throw the previous exception or own SemaphoreAcquiringException here
+            }
+
+            $previousException ??= new SemaphoreAcquiringException($key, 'There were no free locks found');
+
+            throw $previousException;
+        }
+
+        return $locks;
+    }
+}
diff --git a/src/Symfony/Component/Semaphore/Tests/Store/AbstractStoreTestCase.php b/src/Symfony/Component/Semaphore/Tests/Store/AbstractStoreTestCase.php
@@ -204,7 +204,6 @@ public function testPutOffExpirationWhenSaveHasNotBeenCalled()
         $key1 = new Key(__METHOD__, 4, 2);
 
         $this->expectException(SemaphoreExpiredException::class);
-        $this->expectExceptionMessage('The semaphore "Symfony\Component\Semaphore\Tests\Store\AbstractStoreTestCase::testPutOffExpirationWhenSaveHasNotBeenCalled" has expired: the script returns a positive number.');
 
         $store->putOffExpiration($key1, 20);
     }

diff --git a/src/Symfony/Component/Semaphore/Tests/Store/LockStoreTest.php b/src/Symfony/Component/Semaphore/Tests/Store/LockStoreTest.php
@@ -0,0 +1,31 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Semaphore\Tests\Store;
+
+use Symfony\Component\Lock\LockFactory;
+use Symfony\Component\Lock\Store\FlockStore;
+use Symfony\Component\Semaphore\PersistingStoreInterface;
+use Symfony\Component\Semaphore\Store\LockStore;
+
+/**
+ * @author Alexander Schranz <alexander@sulu.io>
+ */
+class LockStoreTest extends AbstractStoreTestCase
+{
+    public function getStore(): PersistingStoreInterface
+    {
+        $lock = new FlockStore();
+        $factory = new LockFactory($lock);
+
+        return new LockStore($factory);
+    }
+}
diff --git a/src/Symfony/Component/Semaphore/composer.json b/src/Symfony/Component/Semaphore/composer.json
@@ -24,7 +24,8 @@
         "psr/log": "^1|^2|^3"
     },
     "require-dev": {
-        "predis/predis": "^1.1|^2.0"
+        "predis/predis": "^1.1|^2.0",
+        "symfony/lock": "^5.4 || ^6.0 || ^7.0"
     },
     "conflict": {
         "symfony/cache": "<6.4"