symfony · fabpot · Sep 12, 2020 · Oct 24, 2018
diff --git a/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Configuration.php b/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Configuration.php
@@ -1041,6 +1041,9 @@ private function addCacheSection(ArrayNodeDefinition $rootNode)
                                     ->scalarNode('provider')
                                         ->info('Overwrite the setting from the default provider for this adapter.')
                                     ->end()
+                                    ->scalarNode('early_expiration_message_bus')
+                                        ->example('"messenger.default_bus" to send early expiration events to the default Messenger bus.')
+                                    ->end()
                                     ->scalarNode('clearer')->end()
                                 ->end()
                             ->end()

diff --git a/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/FrameworkExtension.php b/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/FrameworkExtension.php
@@ -147,6 +147,7 @@
 use Symfony\Component\Yaml\Command\LintCommand as BaseYamlLintCommand;
 use Symfony\Component\Yaml\Yaml;
 use Symfony\Contracts\Cache\CacheInterface;
+use Symfony\Contracts\Cache\CallbackInterface;
 use Symfony\Contracts\Cache\TagAwareCacheInterface;
 use Symfony\Contracts\HttpClient\HttpClientInterface;
 use Symfony\Contracts\Service\ResetInterface;
@@ -436,6 +437,8 @@ public function load(array $configs, ContainerBuilder $container)
             ->addTag('container.env_var_loader');
         $container->registerForAutoconfiguration(EnvVarProcessorInterface::class)
             ->addTag('container.env_var_processor');
+        $container->registerForAutoconfiguration(CallbackInterface::class)
+            ->addTag('container.reversible');
         $container->registerForAutoconfiguration(ServiceLocator::class)
             ->addTag('container.service_locator');
         $container->registerForAutoconfiguration(ServiceSubscriberInterface::class)

diff --git a/src/Symfony/Bundle/FrameworkBundle/Resources/config/cache.php b/src/Symfony/Bundle/FrameworkBundle/Resources/config/cache.php
@@ -25,6 +25,7 @@
 use Symfony\Component\Cache\Adapter\RedisTagAwareAdapter;
 use Symfony\Component\Cache\Adapter\TagAwareAdapter;
 use Symfony\Component\Cache\Marshaller\DefaultMarshaller;
+use Symfony\Component\Cache\Messenger\EarlyExpirationHandler;
 use Symfony\Component\HttpKernel\CacheClearer\Psr6CacheClearer;
 use Symfony\Contracts\Cache\CacheInterface;
 use Symfony\Contracts\Cache\TagAwareCacheInterface;
@@ -212,6 +213,12 @@
                 null, // use igbinary_serialize() when available
             ])
 
+        ->set('cache.early_expiration_handler', EarlyExpirationHandler::class)
+            ->args([
+                service('reverse_container'),
+            ])
+            ->tag('messenger.message_handler')
+
         ->set('cache.default_clearer', Psr6CacheClearer::class)
             ->args([
                 [],

diff --git a/src/Symfony/Bundle/FrameworkBundle/Resources/config/schema/symfony-1.0.xsd b/src/Symfony/Bundle/FrameworkBundle/Resources/config/schema/symfony-1.0.xsd
@@ -284,6 +284,7 @@
         <xsd:attribute name="public" type="xsd:boolean" />
         <xsd:attribute name="default-lifetime" type="xsd:integer" />
         <xsd:attribute name="provider" type="xsd:string" />
+        <xsd:attribute name="early-expiration-message-bus" type="xsd:string" />
         <xsd:attribute name="clearer" type="xsd:string" />
     </xsd:complexType>
 

diff --git a/src/Symfony/Component/Cache/CHANGELOG.md b/src/Symfony/Component/Cache/CHANGELOG.md
@@ -1,6 +1,11 @@
 CHANGELOG
 =========
 
+5.2.0
+-----
+
+ * added integration with Messenger to allow computing cached values in a worker
+
 5.1.0
 -----
 

diff --git a/src/Symfony/Component/Cache/DependencyInjection/CachePoolPass.php b/src/Symfony/Component/Cache/DependencyInjection/CachePoolPass.php
@@ -14,6 +14,7 @@
 use Symfony\Component\Cache\Adapter\AbstractAdapter;
 use Symfony\Component\Cache\Adapter\ArrayAdapter;
 use Symfony\Component\Cache\Adapter\ChainAdapter;
+use Symfony\Component\Cache\Messenger\EarlyExpirationDispatcher;
 use Symfony\Component\DependencyInjection\ChildDefinition;
 use Symfony\Component\DependencyInjection\Compiler\CompilerPassInterface;
 use Symfony\Component\DependencyInjection\ContainerBuilder;
@@ -32,15 +33,21 @@ class CachePoolPass implements CompilerPassInterface
     private $cachePoolClearerTag;
     private $cacheSystemClearerId;
     private $cacheSystemClearerTag;
+    private $reverseContainerId;
+    private $reversibleTag;
+    private $messageHandlerId;
 
-    public function __construct(string $cachePoolTag = 'cache.pool', string $kernelResetTag = 'kernel.reset', string $cacheClearerId = 'cache.global_clearer', string $cachePoolClearerTag = 'cache.pool.clearer', string $cacheSystemClearerId = 'cache.system_clearer', string $cacheSystemClearerTag = 'kernel.cache_clearer')
+    public function __construct(string $cachePoolTag = 'cache.pool', string $kernelResetTag = 'kernel.reset', string $cacheClearerId = 'cache.global_clearer', string $cachePoolClearerTag = 'cache.pool.clearer', string $cacheSystemClearerId = 'cache.system_clearer', string $cacheSystemClearerTag = 'kernel.cache_clearer', string $reverseContainerId = 'reverse_container', string $reversibleTag = 'container.reversible', string $messageHandlerId = 'cache.early_expiration_handler')
     {
         $this->cachePoolTag = $cachePoolTag;
         $this->kernelResetTag = $kernelResetTag;
         $this->cacheClearerId = $cacheClearerId;
         $this->cachePoolClearerTag = $cachePoolClearerTag;
         $this->cacheSystemClearerId = $cacheSystemClearerId;
         $this->cacheSystemClearerTag = $cacheSystemClearerTag;
+        $this->reverseContainerId = $reverseContainerId;
+        $this->reversibleTag = $reversibleTag;
+        $this->messageHandlerId = $messageHandlerId;
     }
 
     /**
@@ -55,13 +62,15 @@ public function process(ContainerBuilder $container)
             $seed .= '.'.$container->getParameter('kernel.container_class');
         }
 
+        $needsMessageHandler = false;
         $allPools = [];
         $clearers = [];
         $attributes = [
             'provider',
             'name',
             'namespace',
             'default_lifetime',
+            'early_expiration_message_bus',
             'reset',
         ];
         foreach ($container->findTaggedServiceIds($this->cachePoolTag) as $id => $tags) {
@@ -155,13 +164,24 @@ public function process(ContainerBuilder $container)
                     if ($tags[0][$attr]) {
                         $pool->addTag($this->kernelResetTag, ['method' => $tags[0][$attr]]);
                     }
+                } elseif ('early_expiration_message_bus' === $attr) {
+                    $needsMessageHandler = true;
+                    $pool->addMethodCall('setCallbackWrapper', [(new Definition(EarlyExpirationDispatcher::class))
+                        ->addArgument(new Reference($tags[0]['early_expiration_message_bus']))
+                        ->addArgument(new Reference($this->reverseContainerId))
+                        ->addArgument((new Definition('callable'))
+                            ->setFactory([new Reference($id), 'setCallbackWrapper'])
+                            ->addArgument(null)
+                        ),
+                    ]);
+                    $pool->addTag($this->reversibleTag);
                 } elseif ('namespace' !== $attr || ArrayAdapter::class !== $class) {
                     $pool->replaceArgument($i++, $tags[0][$attr]);
                 }
                 unset($tags[0][$attr]);
             }
             if (!empty($tags[0])) {
-                throw new InvalidArgumentException(sprintf('Invalid "%s" tag for service "%s": accepted attributes are "clearer", "provider", "name", "namespace", "default_lifetime" and "reset", found "%s".', $this->cachePoolTag, $id, implode('", "', array_keys($tags[0]))));
+                throw new InvalidArgumentException(sprintf('Invalid "%s" tag for service "%s": accepted attributes are "clearer", "provider", "name", "namespace", "default_lifetime", "early_expiration_message_bus" and "reset", found "%s".', $this->cachePoolTag, $id, implode('", "', array_keys($tags[0]))));
             }
 
             if (null !== $clearer) {
@@ -171,6 +191,10 @@ public function process(ContainerBuilder $container)
             $allPools[$name] = new Reference($id, $container::IGNORE_ON_UNINITIALIZED_REFERENCE);
         }
 
+        if (!$needsMessageHandler) {
+            $container->removeDefinition($this->messageHandlerId);
+        }
+
         $notAliasedCacheClearerId = $this->cacheClearerId;
         while ($container->hasAlias($this->cacheClearerId)) {
             $this->cacheClearerId = (string) $container->getAlias($this->cacheClearerId);

diff --git a/src/Symfony/Component/Cache/Messenger/EarlyExpirationDispatcher.php b/src/Symfony/Component/Cache/Messenger/EarlyExpirationDispatcher.php
@@ -0,0 +1,61 @@
+<?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\Cache\Messenger;
+
+use Psr\Log\LoggerInterface;
+use Symfony\Component\Cache\Adapter\AdapterInterface;
+use Symfony\Component\Cache\CacheItem;
+use Symfony\Component\DependencyInjection\ReverseContainer;
+use Symfony\Component\Messenger\MessageBusInterface;
+use Symfony\Component\Messenger\Stamp\HandledStamp;
+
+/**
+ * Sends the computation of cached values to a message bus.
+ */
+class EarlyExpirationDispatcher
+{
+    private $bus;
+    private $reverseContainer;
+    private $callbackWrapper;
+
+    public function __construct(MessageBusInterface $bus, ReverseContainer $reverseContainer, callable $callbackWrapper = null)
+    {
+        $this->bus = $bus;
+        $this->reverseContainer = $reverseContainer;
+        $this->callbackWrapper = $callbackWrapper;
+    }
+
+    public function __invoke(callable $callback, CacheItem $item, bool &$save, AdapterInterface $pool, \Closure $setMetadata, LoggerInterface $logger = null)
+    {
+        if (!$item->isHit() || null === $message = EarlyExpirationMessage::create($this->reverseContainer, $callback, $item, $pool)) {
+            // The item is stale or the callback cannot be reversed: we must compute the value now
+            $logger && $logger->info('Computing item "{key}" online: '.($item->isHit() ? 'callback cannot be reversed' : 'item is stale'), ['key' => $item->getKey()]);
+
+            return null !== $this->callbackWrapper ? ($this->callbackWrapper)($callback, $item, $save, $pool, $setMetadata, $logger) : $callback($item, $save);
+        }
+
+        $envelope = $this->bus->dispatch($message);
+
+        if ($logger) {
+            if ($envelope->last(HandledStamp::class)) {
+                $logger->info('Item "{key}" was computed online', ['key' => $item->getKey()]);
+            } else {
+                $logger->info('Item "{key}" sent for recomputation', ['key' => $item->getKey()]);
+            }
+        }
+
+        // The item's value is not stale, no need to write it to the backend
+        $save = false;
+
+        return $message->getItem()->get() ?? $item->get();
+    }
+}
diff --git a/src/Symfony/Component/Cache/Messenger/EarlyExpirationHandler.php b/src/Symfony/Component/Cache/Messenger/EarlyExpirationHandler.php
@@ -0,0 +1,80 @@
+<?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\Cache\Messenger;
+
+use Symfony\Component\Cache\CacheItem;
+use Symfony\Component\DependencyInjection\ReverseContainer;
+use Symfony\Component\Messenger\Handler\MessageHandlerInterface;
+
+/**
+ * Computes cached values sent to a message bus.
+ */
+class EarlyExpirationHandler implements MessageHandlerInterface
+{
+    private $reverseContainer;
+    private $processedNonces = [];
+
+    public function __construct(ReverseContainer $reverseContainer)
+    {
+        $this->reverseContainer = $reverseContainer;
+    }
+
+    public function __invoke(EarlyExpirationMessage $message)
+    {
+        $item = $message->getItem();
+        $metadata = $item->getMetadata();
+        $expiry = $metadata[CacheItem::METADATA_EXPIRY] ?? 0;
+        $ctime = $metadata[CacheItem::METADATA_CTIME] ?? 0;
+
+        if ($expiry && $ctime) {
+            // skip duplicate or expired messages
+
+            $processingNonce = [$expiry, $ctime];
+            $pool = $message->getPool();
+            $key = $item->getKey();
+
+            if (($this->processedNonces[$pool][$key] ?? null) === $processingNonce) {
+                return;
+            }
+
+            if (microtime(true) >= $expiry) {
+                return;
+            }
+
+            $this->processedNonces[$pool] = [$key => $processingNonce] + ($this->processedNonces[$pool] ?? []);
+
+            if (\count($this->processedNonces[$pool]) > 100) {
+                array_pop($this->processedNonces[$pool]);
+            }
+        }
+
+        static $setMetadata;
+
+        $setMetadata = $setMetadata ?? \Closure::bind(
+            function (CacheItem $item, float $startTime) {
+                if ($item->expiry > $endTime = microtime(true)) {
+                    $item->newMetadata[CacheItem::METADATA_EXPIRY] = $item->expiry;
+                    $item->newMetadata[CacheItem::METADATA_CTIME] = (int) ceil(1000 * ($endTime - $startTime));
+                }
+            },
+            null,
+            CacheItem::class
+        );
+
+        $startTime = microtime(true);
+        $pool = $message->findPool($this->reverseContainer);
+        $callback = $message->findCallback($this->reverseContainer);
+        $value = $callback($item);
+        $setMetadata($item, $startTime);
+        $pool->save($item->set($value));
+    }
+}
diff --git a/src/Symfony/Component/Cache/Messenger/EarlyExpirationMessage.php b/src/Symfony/Component/Cache/Messenger/EarlyExpirationMessage.php
@@ -0,0 +1,97 @@
+<?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\Cache\Messenger;
+
+use Symfony\Component\Cache\Adapter\AdapterInterface;
+use Symfony\Component\Cache\CacheItem;
+use Symfony\Component\DependencyInjection\ReverseContainer;
+
+/**
+ * Conveys a cached value that needs to be computed.
+ */
+final class EarlyExpirationMessage
+{
+    private $item;
+    private $pool;
+    private $callback;
+
+    public static function create(ReverseContainer $reverseContainer, callable $callback, CacheItem $item, AdapterInterface $pool): ?self
+    {
+        try {
+            $item = clone $item;
+            $item->set(null);
+        } catch (\Exception $e) {
+            return null;
+        }
+
+        $pool = $reverseContainer->getId($pool);
+
+        if (\is_object($callback)) {
+            if (null === $id = $reverseContainer->getId($callback)) {
+                return null;
+            }
+
+            $callback = '@'.$id;
+        } elseif (!\is_array($callback)) {
+            $callback = (string) $callback;
+        } elseif (!\is_object($callback[0])) {
+            $callback = [(string) $callback[0], (string) $callback[1]];
+        } else {
+            if (null === $id = $reverseContainer->getId($callback[0])) {
+                return null;
+            }
+
+            $callback = ['@'.$id, (string) $callback[1]];
+        }
+
+        return new self($item, $pool, $callback);
+    }
+
+    public function getItem(): CacheItem
+    {
+        return $this->item;
+    }
+
+    public function getPool(): string
+    {
+        return $this->pool;
+    }
+
+    public function getCallback()
+    {
+        return $this->callback;
+    }
+
+    public function findPool(ReverseContainer $reverseContainer): AdapterInterface
+    {
+        return $reverseContainer->getService($this->pool);
+    }
+
+    public function findCallback(ReverseContainer $reverseContainer): callable
+    {
+        if (\is_string($callback = $this->callback)) {
+            return '@' === $callback[0] ? $reverseContainer->getService(substr($callback, 1)) : $callback;
+        }
+        if ('@' === $callback[0][0]) {
+            $callback[0] = $reverseContainer->getService(substr($callback[0], 1));
+        }
+
+        return $callback;
+    }
+
+    private function __construct(CacheItem $item, string $pool, $callback)
+    {
+        $this->item = $item;
+        $this->pool = $pool;
+        $this->callback = $callback;
+    }
+}