Cache.php in Drupal 8
Same filename and directory in other branches
Namespace
Drupal\Core\CacheFile
core/lib/Drupal/Core/Cache/Cache.phpView source
<?php
namespace Drupal\Core\Cache;
use Drupal\Component\Assertion\Inspector;
use Drupal\Core\Database\Query\SelectInterface;
/**
* Helper methods for cache.
*
* @ingroup cache
*/
class Cache {
/**
* Indicates that the item should never be removed unless explicitly deleted.
*/
const PERMANENT = CacheBackendInterface::CACHE_PERMANENT;
/**
* Merges arrays of cache contexts and removes duplicates.
*
* @param array $a
* Cache contexts array to merge.
* @param array $b
* Cache contexts array to merge.
*
* @return string[]
* The merged array of cache contexts.
*/
public static function mergeContexts(array $a = [], array $b = []) {
$cache_contexts = array_unique(array_merge($a, $b));
assert(\Drupal::service('cache_contexts_manager')
->assertValidTokens($cache_contexts));
sort($cache_contexts);
return $cache_contexts;
}
/**
* Merges arrays of cache tags and removes duplicates.
*
* The cache tags array is returned in a format that is valid for
* \Drupal\Core\Cache\CacheBackendInterface::set().
*
* When caching elements, it is necessary to collect all cache tags into a
* single array, from both the element itself and all child elements. This
* allows items to be invalidated based on all tags attached to the content
* they're constituted from.
*
* @param array $a
* Cache tags array to merge.
* @param array $b
* Cache tags array to merge.
*
* @return string[]
* The merged array of cache tags.
*/
public static function mergeTags(array $a = [], array $b = []) {
assert(Inspector::assertAllStrings($a) && Inspector::assertAllStrings($b), 'Cache tags must be valid strings');
$cache_tags = array_unique(array_merge($a, $b));
sort($cache_tags);
return $cache_tags;
}
/**
* Merges max-age values (expressed in seconds), finds the lowest max-age.
*
* Ensures infinite max-age (Cache::PERMANENT) is taken into account.
*
* @param int $a
* Max age value to merge.
* @param int $b
* Max age value to merge.
*
* @return int
* The minimum max-age value.
*/
public static function mergeMaxAges($a = Cache::PERMANENT, $b = Cache::PERMANENT) {
// If one of the values is Cache::PERMANENT, return the other value.
if ($a === Cache::PERMANENT) {
return $b;
}
if ($b === Cache::PERMANENT) {
return $a;
}
// If none or the values are Cache::PERMANENT, return the minimum value.
return min($a, $b);
}
/**
* Validates an array of cache tags.
*
* Can be called before using cache tags in operations, to ensure validity.
*
* @param string[] $tags
* An array of cache tags.
*
* @deprecated in drupal:8.0.0 and is removed from drupal:9.0.0. Use
* assert(\Drupal\Component\Assertion\Inspector::assertAllStrings($tags))
* instead.
*
* @throws \LogicException
*/
public static function validateTags(array $tags) {
@trigger_error(__NAMESPACE__ . '\\Cache::validateTags() is deprecated in drupal:8.0.0 and is removed from drupal:9.0.0. Use assert(\\Drupal\\Component\\Assertion\\Inspector::assertAllStrings($tags)) instead.', E_USER_DEPRECATED);
if (empty($tags)) {
return;
}
foreach ($tags as $value) {
if (!is_string($value)) {
throw new \LogicException('Cache tags must be strings, ' . gettype($value) . ' given.');
}
}
}
/**
* Build an array of cache tags from a given prefix and an array of suffixes.
*
* Each suffix will be converted to a cache tag by appending it to the prefix,
* with a colon between them.
*
* @param string $prefix
* A prefix string.
* @param array $suffixes
* An array of suffixes. Will be cast to strings.
* @param string $glue
* A string to be used as glue for concatenation. Defaults to a colon.
*
* @return string[]
* An array of cache tags.
*/
public static function buildTags($prefix, array $suffixes, $glue = ':') {
$tags = [];
foreach ($suffixes as $suffix) {
$tags[] = $prefix . $glue . $suffix;
}
return $tags;
}
/**
* Marks cache items from all bins with any of the specified tags as invalid.
*
* @param string[] $tags
* The list of tags to invalidate cache items for.
*/
public static function invalidateTags(array $tags) {
\Drupal::service('cache_tags.invalidator')
->invalidateTags($tags);
}
/**
* Gets all cache bin services.
*
* @return \Drupal\Core\Cache\CacheBackendInterface[]
* An array of cache backend objects keyed by cache bins.
*/
public static function getBins() {
$bins = [];
$container = \Drupal::getContainer();
foreach ($container
->getParameter('cache_bins') as $service_id => $bin) {
$bins[$bin] = $container
->get($service_id);
}
return $bins;
}
/**
* Generates a hash from a query object, to be used as part of the cache key.
*
* This smart caching strategy saves Drupal from querying and rendering to
* HTML when the underlying query is unchanged.
*
* Expensive queries should use the query builder to create the query and then
* call this function. Executing the query and formatting results should
* happen in a #pre_render callback.
*
* @param \Drupal\Core\Database\Query\SelectInterface $query
* A select query object.
*
* @return string
* A hash of the query arguments.
*/
public static function keyFromQuery(SelectInterface $query) {
$query
->preExecute();
$keys = [
(string) $query,
$query
->getArguments(),
];
return hash('sha256', serialize($keys));
}
}