Installation¶

You can install the component in 2 different ways:

• Install it via Composer (symfony/cache on Packagist);
• Use the official Git repository (https://github.com/symfony/cache).

Key Concepts¶

Before starting to use the Cache component, it’s important that you learn the meaning of some key concepts:

Item

A single unit of information stored as a key/value pair, where the key is the unique identifier of the information and the value is its contents;

Pool

A logical repository of cache items. All cache operations (saving items, looking for items, etc.) are performed through the pool. Applications can define as many pools as needed.

Adapter

It implements the actual caching mechanism to store the information in the filesystem, in a database, etc. The component provides several ready to use adapters for common caching backends (Redis, APCu, etc.)

Basic Usage¶

This component is a strict implementation of PSR-6, which means that the API is the same as defined in the standard. Before starting to cache information, create the cache pool using any of the built-in adapters. For example, to create a filesystem-based cache, instantiate Symfony\Component\Cache\Adapter\FilesystemAdapter:

use Symfony\Component\Cache\Adapter\FilesystemAdapter;

$cache = new FilesystemAdapter();

Now you can create, retrieve, update and delete items using this cache pool:

// create a new item by trying to get it from the cache
$numProducts = $cache->getItem('stats.num_products');

// assign a value to the item and save it
$numProducts->set(4711);
$cache->save($numProducts);

// retrieve the cache item
$numProducts = $cache->getItem('stats.num_products');
if (!$numProducts->isHit()) {
    // ... item does not exists in the cache
}
// retrieve the value stored by the item
$total = $numProducts->get();

// remove the cache item
$cache->deleteItem('stats.num_products');

Advanced Usage¶