Adapters For Interoperability between PSR-6 and PSR-16 Cache

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Sometimes, you may have a Cache object that implements the PSR-16 standard, but need to pass it to an object that expects a PSR-6 cache adapter. Or, you might have the opposite situation. The cache component contains two classes for bidirectional interoperability between PSR-6 and PSR-16 caches.

Using a PSR-16 Cache Object as a PSR-6 Cache

Suppose you want to work with a class that requires a PSR-6 Cache pool object. For example:

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        use Psr\Cache\CacheItemPoolInterface;

// just a made-up class for the example
class GitHubApiClient
{
    // ...

    // this requires a PSR-6 cache object
    public function __construct(CacheItemPoolInterface $cachePool)
    {
        // ...
    }
}
    

But, you already have a PSR-16 cache object, and you'd like to pass this to the class instead. No problem! The Cache component provides the SimpleCacheAdapter class for exactly this use-case:

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        use Symfony\Component\Cache\Adapter\SimpleCacheAdapter;
use Symfony\Component\Cache\Simple\FilesystemCache;

// the PSR-16 cache object that you want to use
$psr16Cache = new FilesystemCache();

// a PSR-6 cache that uses your cache internally!
$psr6Cache = new SimpleCacheAdapter($psr16Cache);

// now use this wherever you want
$githubApiClient = new GitHubApiClient($psr6Cache);
    

Using a PSR-6 Cache Object as a PSR-16 Cache

Suppose you want to work with a class that requires a PSR-16 Cache object. For example:

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        use Psr\SimpleCache\CacheInterface;

// just a made-up class for the example
class GitHubApiClient
{
    // ...

    // this requires a PSR-16 cache object
    public function __construct(CacheInterface $cache)
    {
        // ...
    }
}
    

But, you already have a PSR-6 cache pool object, and you'd like to pass this to the class instead. No problem! The Cache component provides the Psr6Cache class for exactly this use-case:

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        use Symfony\Component\Cache\Adapter\FilesystemAdapter;
use Symfony\Component\Cache\Simple\Psr6Cache;

// the PSR-6 cache object that you want to use
$psr6Cache = new FilesystemAdapter();

// a PSR-16 cache that uses your cache internally!
$psr16Cache = new Psr6Cache($psr6Cache);

// now use this wherever you want
$githubApiClient = new GitHubApiClient($psr16Cache);
    

This work, including the code samples, is licensed under a Creative Commons BY-SA 3.0 license.

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