Adding multihost - locking

Adding Unit-Tests for it

src/Core/Cache/ArrayCache.php

@@ -0,0 +1,83 @@
+<?php
+
+namespace Friendica\Core\Cache;
+
+
+use Friendica\Core\Cache;
+
+/**
+ * @brief Implementation of the IMemoryCacheDriver mainly for testing purpose
+ *
+ * Class ArrayCache
+ *
+ * @package Friendica\Core\Cache
+ */
+class ArrayCache implements IMemoryCacheDriver
+{
+	use TraitCompareDelete;
+
+	/** @var array Array with the cached data */
+	protected $cachedData = array();
+
+	/**
+	 * (@inheritdoc)
+	 */
+	public function get($key)
+	{
+		if (isset($this->cachedData[$key])) {
+			return $this->cachedData[$key];
+		}
+		return null;
+	}
+
+	/**
+	 * (@inheritdoc)
+	 */
+	public function set($key, $value, $ttl = Cache::FIVE_MINUTES)
+	{
+		$this->cachedData[$key] = $value;
+		return true;
+	}
+
+	/**
+	 * (@inheritdoc)
+	 */
+	public function delete($key)
+	{
+		unset($this->cachedData[$key]);
+		return true;
+	}
+
+	/**
+	 * (@inheritdoc)
+	 */
+	public function clear()
+	{
+		$this->cachedData = [];
+		return true;
+	}
+
+	/**
+	 * (@inheritdoc)
+	 */
+	public function add($key, $value, $ttl = Cache::FIVE_MINUTES)
+	{
+		if (isset($this->cachedData[$key])) {
+			return false;
+		} else {
+			return $this->set($key, $value, $ttl);
+		}
+	}
+
+	/**
+	 * (@inheritdoc)
+	 */
+	public function compareSet($key, $oldValue, $newValue, $ttl = Cache::FIVE_MINUTES)
+	{
+		if ($this->get($key) === $oldValue) {
+			return $this->set($key, $newValue);
+		} else {
+			return false;
+		}
+	}
+}