Add ICacheDriver->getAllKeys method

src/Core/Cache.php

@@ -46,6 +46,29 @@ class Cache extends \Friendica\BaseObject
 		return self::$driver;
 	}
 
+	/**
+	 * @brief Returns all the cache keys sorted alphabetically
+	 *
+	 * @return array|null Null if the driver doesn't support this feature
+	 */
+	public static function getAllKeys()
+	{
+		$time = microtime(true);
+
+		$return = self::getDriver()->getAllKeys();
+
+		// Keys are prefixed with the node hostname, let's remove it
+		array_walk($return, function (&$value) {
+			$value = preg_replace('/^' . self::getApp()->get_hostname() . ':/', '', $value);
+		});
+
+		sort($return);
+
+		self::getApp()->save_timestamp($time, 'cache');
+
+		return $return;
+	}
+
 	/**
 	 * @brief Fetch cached data according to the key
 	 *

src/Core/Cache/ArrayCache.php

@@ -19,6 +19,14 @@ class ArrayCache extends AbstractCacheDriver implements IMemoryCacheDriver
 	/** @var array Array with the cached data */
 	protected $cachedData = array();
 
+	/**
+	 * (@inheritdoc)
+	 */
+	public function getAllKeys()
+	{
+		return array_keys($this->cachedData);
+	}
+
 	/**
 	 * (@inheritdoc)
 	 */

src/Core/Cache/DatabaseCacheDriver.php

@@ -13,6 +13,16 @@ use Friendica\Util\DateTimeFormat;
  */
 class DatabaseCacheDriver extends AbstractCacheDriver implements ICacheDriver
 {
+	/**
+	 * (@inheritdoc)
+	 */
+	public function getAllKeys()
+	{
+		$stmt = DBA::select('cache', ['k'], ['`expires` >= ?', DateTimeFormat::utcNow()]);
+
+		return DBA::toArray($stmt);
+	}
+
 	/**
 	 * (@inheritdoc)
 	 */

src/Core/Cache/ICacheDriver.php

@@ -11,6 +11,13 @@ use Friendica\Core\Cache;
  */
 interface ICacheDriver
 {
+	/**
+	 * Lists all cache keys
+	 *
+	 * @return array|null Null if it isn't supported by the cache driver
+	 */
+	public function getAllKeys();
+
 	/**
 	 * Fetches cached data according to the key
 	 *

src/Core/Cache/MemcacheCacheDriver.php

@@ -40,6 +40,28 @@ class MemcacheCacheDriver extends AbstractCacheDriver implements IMemoryCacheDri
 		}
 	}
 
+	/**
+	 * (@inheritdoc)
+	 */
+	public function getAllKeys()
+	{
+		$list = [];
+		$allSlabs = $this->memcache->getExtendedStats('slabs');
+		foreach($allSlabs as $slabs) {
+			foreach(array_keys($slabs) as $slabId) {
+				$cachedump = $this->memcache->getExtendedStats('cachedump', (int)$slabId);
+				foreach($cachedump as $keys => $arrVal) {
+					if (!is_array($arrVal)) {
+						continue;
+					}
+					$list = array_merge($list, array_keys($arrVal));
+				}
+			}
+		}
+
+		return $list;
+	}
+
 	/**
 	 * (@inheritdoc)
 	 */

src/Core/Cache/MemcachedCacheDriver.php

@@ -53,6 +53,14 @@ class MemcachedCacheDriver extends AbstractCacheDriver implements IMemoryCacheDr
 		}
 	}
 
+	/**
+	 * (@inheritdoc)
+	 */
+	public function getAllKeys()
+	{
+		return $this->memcached->getAllKeys();
+	}
+
 	/**
 	 * (@inheritdoc)
 	 */

src/Core/Cache/RedisCacheDriver.php

@@ -38,6 +38,14 @@ class RedisCacheDriver extends AbstractCacheDriver implements IMemoryCacheDriver
 		}
 	}
 
+	/**
+	 * (@inheritdoc)
+	 */
+	public function getAllKeys()
+	{
+		return null;
+	}
+
 	/**
 	 * (@inheritdoc)
 	 */