Events & Telemetry

Async Cache PHP dispatches PSR-14 events to help you monitor and debug cache behavior.

Available Events

All events reside in the Fyennyi\AsyncCache\Event namespace.

Event Class
CacheHitEvent
CacheMissEvent
CacheStatusEvent
RateLimitExceededEvent

Setting Up an Event Dispatcher

You can pass any PSR-14 compliant Event Dispatcher (like Symfony's) to the builder.

use Symfony\Component\EventDispatcher\EventDispatcher;
use Fyennyi\AsyncCache\AsyncCacheBuilder;

$dispatcher = new EventDispatcher();

// Add a listener
$dispatcher->addListener(CacheHitEvent::class, function ($event) {
    echo "Cache Hit for key: " . $event->key . "\n";
});

$manager = AsyncCacheBuilder::create($adapter)
    ->withEventDispatcher($dispatcher)
    ->build();

Telemetry Logging

The CacheStatusEvent is particularly useful for logging metrics (e.g., to Prometheus or DataDog). It provides: - Duration: How long the lookup took. - Status: Why the result was returned (Hit, Miss, Stale fallback, etc.). - Tags: Categories associated with the key.