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Diffstat (limited to 'lib/classes/cache/Cache.php')
| -rw-r--r-- | lib/classes/cache/Cache.php | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/lib/classes/cache/Cache.php b/lib/classes/cache/Cache.php new file mode 100644 index 0000000..be703cf --- /dev/null +++ b/lib/classes/cache/Cache.php @@ -0,0 +1,213 @@ +<?php + +namespace Studip\Cache; + +use Psr\Cache\CacheItemInterface; +use Psr\Cache\CacheItemPoolInterface; + +/** + * An abstract class which has to be extended by instances returned from + * \Studip\Cache\Factory#getCache + * + * @author Marco Diedrich (mdiedric@uos) + * @author Marcus Lunzenauer (mlunzena@uos.de) + * @author Moritz Strohm <strohm@data-quest.de> + * @copyright (c) Authors + * @since 1.6 + * @license GPL2 or any later version + */ +abstract class Cache implements CacheItemPoolInterface +{ + const DEFAULT_EXPIRATION = 12 * 60 * 60; // 12 hours + + /** + * @return string A translateable display name for this cache class. + */ + abstract public static function getDisplayName(): string; + + /** + * Get some statistics from cache, like number of entries, hit rate or + * whatever the underlying cache provides. + * Results are returned in form of an array like + * "[ + * [ + * 'name' => <displayable name> + * 'value' => <value of the current stat> + * ] + * ]" + * + * @return array + */ + abstract public function getStats(): array; + + /** + * Return the Vue component name and props that handle configuration. + * The associative array is of the form + * [ + * 'component' => <Vue component name>, + * 'props' => <Properties for component> + * ] + * + * @return array + */ + abstract public static function getConfig(): array; + + /** + * Expire item from the cache. + * + * Example: + * + * # expires foo + * $cache->expire('foo'); + * + * @param string $arg a single key + */ + abstract public function expire($arg); + + /** + * Expire all items from the cache. + */ + abstract public function flush(); + + /** + * @see CacheItemPoolInterface::getItem + */ + abstract public function getItem(string $key): CacheItemInterface; + + /** + * @see CacheItemPoolInterface::hasItem + */ + abstract public function hasItem(string $key): bool; + + /** + * @var array An array of deferred items that shall be saved only + * when commit() is called. This is only used in PSR-6 cache methods. + */ + protected array $deferred_items = []; + + /** + * Retrieve item from the server. + * + * Example: + * + * # reads foo + * $foo = $cache->reads('foo'); + * + * @param string $arg a single key + * + * @return mixed the previously stored data if an item with such a key + * exists on the server or FALSE on failure. + * + * @deprecated To be removed with Stud.IP 7.0. + */ + public function read($arg) + { + $item = $this->getItem($arg); + if ($item->isHit()) { + return $item->get(); + } + return false; + } + + /** + * Store data at the server. + * + * @param string $name the item's key. + * @param mixed $content the item's content (will be serialized if necessary). + * @param int $expires the item's expiry time in seconds. Optional, defaults to 12h. + * + * @return bool returns TRUE on success or FALSE on failure. + + * @deprecated To be removed with Stud.IP 7.0. + */ + public function write($name, $content, $expires = self::DEFAULT_EXPIRATION) + { + $item = new Item($name, $content, $expires); + + return $this->save($item); + } + + /** + * Calculates the expiration by a cache item. If that cannot be determined, + * the default expiration period is returned. + * + * @param Item $item The item from which to get the expiration time. + * + * @return int The time from now until the expiration in seconds. + */ + public function getExpiration(CacheItemInterface $item) : int + { + $expiration = self::DEFAULT_EXPIRATION; + if ($item instanceof Item) { + $expiration = $item->getExpirationInSeconds(); + } + return $expiration; + } + + // PSR-6 CacheItemPoolInterface: + + /** + * @see CacheItemPoolInterface::getItems + */ + public function getItems(array $keys = []): iterable + { + $items = []; + foreach ($keys as $key) { + $item = $this->getItem($key); + if ($item instanceof Item) { + $items[] = $item; + } + } + return $items; + } + + /** + * @see CacheItemPoolInterface::clear + */ + public function clear(): bool + { + $this->deferred_items = []; + $this->flush(); + return true; + } + + /** + * @see CacheItemPoolInterface::deleteItem + */ + public function deleteItem($key): bool + { + $this->expire($key); + return true; + } + + /** + * @see CacheItemPoolInterface::deleteItems + */ + public function deleteItems(array $keys): bool + { + foreach ($keys as $key) { + $this->expire($key); + } + return true; + } + + /** + * @see CacheItemPoolInterface::saveDeferred + */ + public function saveDeferred(CacheItemInterface $item): bool + { + $this->deferred_items[] = $item; + return true; + } + + /** + * @see CacheItemPoolInterface::commit + */ + public function commit(): bool + { + foreach ($this->deferred_items as $item) { + $this->save($item); + } + return true; + } +} |