Rename *CacheDriver to *Cache because they don't act as driver anymore

src/Core/Cache/AbstractCache.php

@@ -0,0 +1,91 @@
+<?php
+
+namespace Friendica\Core\Cache;
+
+/**
+ * Abstract class for common used functions
+ *
+ * Class AbstractCache
+ *
+ * @package Friendica\Core\Cache
+ */
+abstract class AbstractCache implements ICache
+{
+	/**
+	 * @var string The hostname
+	 */
+	private $hostName;
+
+	public function __construct(string $hostName)
+	{
+		$this->hostName = $hostName;
+	}
+
+	/**
+	 * Returns the prefix (to avoid namespace conflicts)
+	 *
+	 * @return string
+	 * @throws \Exception
+	 */
+	protected function getPrefix()
+	{
+		// We fetch with the hostname as key to avoid problems with other applications
+		return $this->hostName;
+	}
+
+	/**
+	 * @param string $key The original key
+	 * @return string        The cache key used for the cache
+	 * @throws \Exception
+	 */
+	protected function getCacheKey($key)
+	{
+		return $this->getPrefix() . ":" . $key;
+	}
+
+	/**
+	 * @param array $keys   A list of cached keys
+	 * @return array        A list of original keys
+	 */
+	protected function getOriginalKeys($keys)
+	{
+		if (empty($keys)) {
+			return [];
+		} else {
+			// Keys are prefixed with the node hostname, let's remove it
+			array_walk($keys, function (&$value) {
+				$value = preg_replace('/^' . $this->hostName . ':/', '', $value);
+			});
+
+			sort($keys);
+
+			return $keys;
+		}
+	}
+
+	/**
+	 * Filters the keys of an array with a given prefix
+	 * Returns the filtered keys as an new array
+	 *
+	 * @param array $array The array, which should get filtered
+	 * @param string|null $prefix The prefix (if null, all keys will get returned)
+	 *
+	 * @return array The filtered array with just the keys
+	 */
+	protected function filterArrayKeysByPrefix($array, $prefix = null)
+	{
+		if (empty($prefix)) {
+			return array_keys($array);
+		} else {
+			$result = [];
+
+			foreach (array_keys($array) as $key) {
+				if (strpos($key, $prefix) === 0) {
+					array_push($result, $key);
+				}
+			}
+
+			return $result;
+		}
+	}
+}