MultiLevelCache Symfony Bundle

A high-performance, multi-level caching system for Symfony applications. This bundle provides a flexible, extensible, and developer-friendly way to combine multiple cache backends (memory, Redis, file, etc.) for optimal speed and reliability.

---

Features

• Multi-level cache (memory, Redis, file, etc.)
• Pluggable cache implementations
• Cache statistics and profiling (Symfony Profiler integration)
• Beta decay and TTL randomization to prevent stampedes
• Easy integration with Symfony Dependency Injection
• Extensible via interfaces and factories
• Exception handling and diagnostics

---

Requirements

• PHP >= 8.4
• Symfony >= 7.4
• Redis (optional, for Redis cache level)

---

Installation

Install via Composer from GitHub:

1. Add the repository to your composer.json:

   {
     "repositories": [
       {
         "type": "vcs",
         "url": "https://github.com/tbessenreither/multi-level-cache"
       }
     ]
   }

2. Require the package:

   composer require tbessenreither/multi-level-cache

3. Enable the Bundle in config/bundles.php:

   Tbessenreither\MultiLevelCache\Bundle\MultiLevelCacheBundle::class => ['all' => true],

4. Configure Environment Variables as needed:
   • REDIS_DSN (if using Redis)
   • MLC_DISABLE_READ (optional, disables cache reads)
   • MLC_COLLECT_ENHANCED_DATA (optional, enables enhanced data collection but has performance impact)

---

Usage

You can use the multi-level cache in two ways:

1. Setup

1.1 Manual Setup in Your Service/Controller

You can instantiate and configure the MultiLevelCacheService directly in your constructor, providing the cache implementations you want to use. The Redis client should be injected via dependency injection:

use Tbessenreither\MultiLevelCache\Service\MultiLevelCacheService;
use Tbessenreither\MultiLevelCache\Service\Implementations\InMemoryCacheService;
use Tbessenreither\MultiLevelCache\Service\Implementations\DirectRedisCacheService;
use Redis; // or RedisCluster

public function __construct(Redis $redisClient) {
    $inMemory = new InMemoryCacheService();
    $redis = new DirectRedisCacheService($redisClient);
    $this->cache = new MultiLevelCacheService([
        $inMemory,
        $redis,
    ]);
}

1.2 Using the Factory (Recommended for Symfony DI)

Inject the MultiLevelCacheFactory and use it to create a pre-configured cache service:

use Tbessenreither\MultiLevelCache\Factory\MultiLevelCacheFactory;

public function __construct(MultiLevelCacheFactory $cacheFactory) {
    $this->cache = $cacheFactory->createDefault2LevelCache();
}

2. Using the Cache (Identical for Both Approaches)

Once you have a MultiLevelCacheService instance (from either method above), usage is identical:

$this->cache->set('my_key', $object, 3600);
$value = $this->cache->get('my_key', function() {
    // This callback is called only if there is a cache miss.
    // Return the value to be cached and returned.
    return $expensiveComputationOrFetch();
}, 3600);
$this->cache->delete('my_key');

---

Architecture Overview

• Bundle: Entry point for Symfony integration (src/Bundle/MultiLevelCacheBundle.php)
• Service: Main cache logic (src/Service/MultiLevelCacheService.php)
• Factory: Helper for common cache setups (src/Factory/MultiLevelCacheFactory.php)
• Implementations:
  • In-memory (src/Service/Implementations/InMemoryCacheService.php)
  • Redis (src/Service/Implementations/DirectRedisCacheService.php)
  • File (src/Service/Implementations/FileCacheService.php)
• Key Generator: (src/Service/CacheKeyGeneratorService.php)
• Interfaces:
  • MultiLevelCacheImplementationInterface
  • CacheInformationInterface
• DTOs: Data transfer objects for cache and profiling (src/Dto/)
• Enums: Error and warning enums (src/Enum/)
• Exceptions: Custom exception types (src/Exception/)
• Profiler Integration: Data collector and templates (src/DataCollector/, src/Templates/Profiler/)

---

Configuration Example

Note: While it is possible to configure the MultiLevelCacheService directly in services.yaml, this approach is discouraged. The intended and recommended way is to use the MultiLevelCacheFactory for setup and configuration.

# config/services.yaml
services:
    Tbessenreither\MultiLevelCache\Service\MultiLevelCacheService:
        arguments:
            $caches:
                - '@Tbessenreither\MultiLevelCache\Service\Implementations\InMemoryCacheService'
                - '@Tbessenreither\MultiLevelCache\Service\Implementations\DirectRedisCacheService'
            $writeL0OnSet: true
            $ttlRandomnessSeconds: 10
            $cacheGroupName: 'default'

---

Testing

Run PHPUnit tests:

ddev composer test

---

File Overview

• src/Bundle/: Symfony bundle integration
• src/Service/: Main service and cache implementations
• src/Factory/: Factory for cache setup
• src/Dto/: Data transfer objects
• src/Enum/: Error and warning enums
• src/Exception/: Custom exceptions
• src/Interface/: Interfaces for extensibility
• src/DataCollector/: Profiler and statistics
• src/Templates/Profiler/: Symfony profiler templates
• tests/: PHPUnit tests

---

License

MIT