Filesystem Cache Adapter

Filesystem Cache Adapter

This adapter offers improved application performance for those who cannot install tools like APCu or Redis in their environment. It stores the cache item expiration and content as regular files in a collection of directories on a locally mounted filesystem.

Tip

The performance of this adapter can be greatly increased by utilizing a temporary, in-memory filesystem, such as tmpfs on Linux, or one of the many other RAM disk solutions available.

The FilesystemAdapter can optionally be provided a namespace, default cache lifetime, and cache root path as constructor parameters:

  1. use Symfony\Component\Cache\Adapter\FilesystemAdapter;
  3. $cache = new FilesystemAdapter(
  5.     // a string used as the subdirectory of the root cache directory, where cache
  6.     // items will be stored
  7.     $namespace = '',
  9.     // the default lifetime (in seconds) for cache items that do not define their
  10.     // own lifetime, with a value 0 causing items to be stored indefinitely (i.e.
  11.     // until the files are deleted)
  12.     $defaultLifetime = 0,
  14.     // the main cache directory (the application needs read-write permissions on it)
  15.     // if none is specified, a directory is created inside the system temporary directory
  16.     $directory = null
  17. );

Caution

The overhead of filesystem IO often makes this adapter one of the slower choices. If throughput is paramount, the in-memory adapters (Apcu, Memcached, and Redis) or the database adapters (Doctrine and PDO) are recommended.

Note

This adapter implements Symfony\Component\Cache\PruneableInterface, enabling manual pruning of expired cache items by calling its prune() method.

Working with Tags

In order to use tag-based invalidation, you can wrap your adapter in Symfony\Component\Cache\Adapter\TagAwareAdapter, but it’s often more interesting to use the dedicated Symfony\Component\Cache\Adapter\FilesystemTagAwareAdapter. Since tag invalidation logic is implemented using links on filesystem, this adapter offers better read performance when using tag-based invalidation:

  1. use Symfony\Component\Cache\Adapter\FilesystemTagAwareAdapter;
  3. $cache = new FilesystemTagAwareAdapter();

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