PHP Files Cache Adapter

Similarly to Filesystem Adapter, this cache implementation writes cache entries out to disk, but unlike the Filesystem cache adapter, the PHP Files cache adapter writes and reads back these cache files as native PHP code. For example, caching the value ['my', 'cached', 'array'] will write out a cache file similar to the following:

<?php return [

    // the cache item expiration
    0 => 9223372036854775807,

    // the cache item contents
    1 => [
        0 => 'my',
        1 => 'cached',
        2 => 'array',
    ],

];

Note

This adapter requires turning on the opcache.enable php.ini setting. As cache items are included and parsed as native PHP code and due to the way OPcache handles file includes, this adapter has the potential to be much faster than other filesystem-based caches.

Caution

While it supports updates and because it is using OPcache as a backend, this adapter is better suited for append-mostly needs. Using it in other scenarios might lead to periodical reset of the OPcache memory, potentially leading to degraded performance.

The PhpFilesAdapter can optionally be provided a namespace, default cache lifetime, and cache directory path as constructor arguments:

use Symfony\Component\Cache\Adapter\PhpFilesAdapter;

$cache = new PhpFilesAdapter(

    // a string used as the subdirectory of the root cache directory, where cache
    // items will be stored
    $namespace = '',

    // the default lifetime (in seconds) for cache items that do not define their
    // own lifetime, with a value 0 causing items to be stored indefinitely (i.e.
    // until the files are deleted)
    $defaultLifetime = 0,

    // the main cache directory (the application needs read-write permissions on it)
    // if none is specified, a directory is created inside the system temporary directory
    $directory = null
);

Note

Since Symfony 3.4, this adapter implements PruneableInterface, allowing for manual pruning of expired cache entries by calling its prune() method.