Psr6 Symfony Http Cache Store Laravel Package

Getting Started

Minimal Setup

1. Installation

   composer require toflar/psr6-symfony-http-cache-store:^4.3
   

   Requires PHP 8.1+ and is compatible with Symfony 8. Add to your config/cache.php under stores:

   'http_cache' => [
       'driver' => 'toflar_psr6_http_cache',
       'options' => [
           'cache_dir' => storage_path('framework/cache/http'),
           'cache_pool' => 'cache.array', // Your PSR-6 cache pool (e.g., Redis, APCu)
           'ttl' => 3600, // Default TTL in seconds
       ],
   ],
   

2. First Use Case Replace Symfony’s default HttpCache store in your HttpCache configuration (e.g., config/packages/symfony_http_cache.yaml):

   framework:
       http_cache:
           store: \Toflar\Psr6SymfonyHttpCacheStore\Store
   

   Now leverage PSR-6 cache pools (e.g., Redis, APCu) for storage while keeping Symfony’s HTTP cache logic.

Implementation Patterns

Workflows

1. Tag-Based Invalidation Use tags to invalidate related cache entries (e.g., by product ID or user role):

   $cachePool->deleteTagged('product_123'); // Invalidates all entries tagged with 'product_123'
   

   Note: Ensure your PSR-6 pool supports tags (e.g., cache.redis or cache.database; cache.array does not).

2. Auto-Pruning Configure pruning in options:

   'prune' => [
       'interval' => 3600, // Check every hour
       'max_entries' => 10000, // Keep at most 10k entries
       'ttl_threshold' => 300, // Ignore entries expiring within 5 minutes
   ],
   

   Run pruning manually via:

   $store->prune();
   

3. TTL Overrides Set per-entry TTLs:

   $store->save($request, $response, new \DateInterval('PT1H')); // 1-hour TTL
   

Integration Tips

• With Symfony HTTP Cache Middleware Replace the default store in config/packages/symfony_http_cache.yaml:

  framework:
      http_cache:
          store: \Toflar\Psr6SymfonyHttpCacheStore\Store
  

• Custom Cache Pools Inject your PSR-6 pool via service container (e.g., Redis, Doctrine Cache):

  $store = new Store($cachePool, $cacheDir, $ttl);
  

• Event Listeners Hook into HttpCacheStoreEvents (e.g., CacheMiss, CacheHit) for analytics or logging:

  $this->eventDispatcher->addListener(
      \Toflar\Psr6SymfonyHttpCacheStore\Event\HttpCacheStoreEvents::CACHE_MISS,
      fn($event) => \Log::debug('Cache miss for: ' . $event->getRequest()->getUri())
  );
  

Gotchas and Tips

Pitfalls

1. Tagging Limitations

   • Tags are not automatically synced with the underlying PSR-6 pool. Ensure your pool supports tags (e.g., cache.redis or cache.database; cache.array does not).
   • Fix: Use a tag-aware pool like predis/predis or doctrine/cache.

2. Pruning Overhead

   • Frequent pruning on large caches may impact performance.
   • Fix: Schedule pruning during low-traffic periods or use a background job (e.g., Laravel Queues).

3. TTL Granularity

   • The store uses the shortest TTL of all entries during pruning. Override with prune['ttl_threshold'] to ignore entries near expiration.

4. PHP/Symfony Version Compatibility

   • Breaking: Requires PHP 8.1+ and Symfony 8. Older versions (e.g., PHP 8.0, Symfony 7) are no longer supported.
   • Fix: Update dependencies if migrating from older versions.

Debugging

• Log Pruning Enable debug mode in config:

  'prune' => [
      'debug' => true, // Logs pruned entries
  ],
  

• Check Cache Hits/Misses Use Symfony’s HttpCacheEventListener to log events:

  $this->eventDispatcher->addListener(
      \Toflar\Psr6SymfonyHttpCacheStore\Event\HttpCacheStoreEvents::CACHE_MISS,
      fn($event) => \Log::debug('Cache miss for: ' . $event->getRequest()->getUri())
  );
  

Extension Points

1. Custom Pruning Logic Extend Store and override prune():

   class CustomStore extends Store {
       protected function prune(): void {
           // Custom logic (e.g., exclude certain tags)
           parent::prune();
       }
   }
   

2. Add Metadata Store extra metadata (e.g., cache-key:metadata) by extending CacheEntry:

   $entry = new CacheEntry($request, $response, $ttl);
   $entry->setMetadata(['user_id' => auth()->id()]);
   $this->save($entry);
   

3. HTTP Headers Override getVaryHeaders() to customize cache keys:

   $store->setVaryHeaders(['Accept-Language', 'User-Agent']);
   

4. PHP 8.5 Features Leverage PHP 8.5 features (e.g., typed class constants, new attributes) in custom extensions:

   class ExtendedStore extends Store {
       public const MAX_TTL = 86400; // Typed constant (PHP 8.5+)
   }