drupal/core/includes/cache.inc

70 lines
2.1 KiB
PHP

<?php
/**
* @file
* Functions and interfaces for cache handling.
*/
/**
* Instantiates and statically caches the correct class for a cache bin.
*
* By default, this returns an instance of the Drupal\Core\Cache\DatabaseBackend
* class.
*
* Classes implementing Drupal\Core\Cache\CacheBackendInterface can register
* themselves both as a default implementation and for specific bins.
*
* @param $bin
* The cache bin for which the cache object should be returned, defaults to
* 'cache'.
*
* @return Drupal\Core\Cache\CacheBackendInterface
* The cache object associated with the specified bin.
*
* @see Drupal\Core\Cache\CacheBackendInterface
*/
function cache($bin = 'cache') {
// Temporary backwards compatibiltiy layer, allow old style prefixed cache
// bin names to be passed as arguments.
$bin = str_replace('cache_', '', $bin);
// We do not use drupal_static() here because we do not want to change the
// storage of a cache bin mid-request.
static $cache_objects;
if (!isset($cache_objects[$bin])) {
$cache_backends = cache_get_backends();
$class = isset($cache_backends[$bin]) ? $cache_backends[$bin] : $cache_backends['cache'];
$cache_objects[$bin] = new $class($bin);
}
return $cache_objects[$bin];
}
/**
* Invalidates the items associated with given list of tags.
*
* Many sites have more than one active cache backend, and each backend my use
* a different strategy for storing tags against cache items, and invalidating
* cache items associated with a given tag.
*
* When invalidating a given list of tags, we iterate over each cache backend,
* and call invalidate on each.
*
* @param array $tags
* The list of tags to invalidate cache items for.
*/
function cache_invalidate(array $tags) {
foreach (cache_get_backends() as $bin => $class) {
cache($bin)->invalidateTags($tags);
}
}
/**
* Returns a list of cache backends for this site.
*
* @return
* An associative array with cache bins as keys, and backend classes as value.
*/
function cache_get_backends() {
return variable_get('cache_classes', array('cache' => 'Drupal\Core\Cache\DatabaseBackend'));
}