Async Cache PHP

An asynchronous caching abstraction layer for PHP with built-in rate limiting and stale-while-revalidate support.

Overview

fyennyi/async-cache-php is designed to wrap promise-based operations (like Guzzle Promises) to provide robust caching strategies suitable for high-load or rate-limited API clients.

It solves the common problem of handling expired cache items when the underlying data source (e.g., an external API) is currently rate-limited or slow.

Key Features

• Asynchronous Caching: Wraps PromiseInterface or any callable to handle caching transparently without blocking execution.
• Stale-While-Revalidate: Supports background revalidation and stale-on-error patterns.
• X-Fetch Algorithm: Prevents cache stampedes (dog-pile effect) via probabilistic early recomputation.
• Atomic Operations: Support for atomic increment and decrement operations using Symfony Lock.
• Rate Limiting Integration: Built-in support for Symfony Rate Limiter for request throttling.
• Logical vs. Physical TTL: Separates the "freshness" of data from its "existence" in the cache.
• Universal Adapters: Works with PSR-16, ReactPHP Cache, or native Async adapters.