Created ArrayCache class

- can be used to enable caching in a request without the need for any storage
- useful for example in complex console tasks that should still be independed

framework/caching/ArrayCache.php

@@ -0,0 +1,86 @@
+<?php
+/**
+ * @link http://www.yiiframework.com/
+ * @copyright Copyright (c) 2008 Yii Software LLC
+ * @license http://www.yiiframework.com/license/
+ */
+
+namespace yii\caching;
+
+/**
+ * ArrayCache provides caching for the current request only by storing the values in an array.
+ *
+ * See [[Cache]] for common cache operations that ArrayCache supports.
+ *
+ * Unlike the [[Cache]], ArrayCache allows the expire parameter of [[set]], [[add]], [[mset]] and [[madd]] to
+ * be a floating point number, so you may specify the time in milliseconds (e.g. 0.1 will be 100 milliseconds).
+ *
+ * @author Carsten Brandt <mail@cebe.cc>
+ * @since 2.0
+ */
+class ArrayCache extends Cache
+{
+    private $_cache;
+
+
+    /**
+     * @inheritdoc
+     */
+    public function exists($key)
+    {
+        $key = $this->buildKey($key);
+        return isset($this->_cache[$key]) && ($this->_cache[$key][1] === 0 || $this->_cache[$key][1] > microtime(true));
+    }
+
+    /**
+     * @inheritdoc
+     */
+    protected function getValue($key)
+    {
+        if (isset($this->_cache[$key]) && ($this->_cache[$key][1] === 0 || $this->_cache[$key][1] > microtime(true))) {
+            return $this->_cache[$key][0];
+        } else {
+            return false;
+        }
+    }
+
+    /**
+     * @inheritdoc
+     */
+    protected function setValue($key, $value, $duration)
+    {
+        $this->_cache[$key] = [$value, $duration === 0 ? 0 : microtime(true) + $duration];
+        return true;
+    }
+
+    /**
+     * @inheritdoc
+     */
+    protected function addValue($key, $value, $duration)
+    {
+        if (isset($this->_cache[$key]) && ($this->_cache[$key][1] === 0 || $this->_cache[$key][1] > microtime(true))) {
+            return false;
+        } else {
+            $this->_cache[$key] = [$value, $duration === 0 ? 0 : microtime(true) + $duration];
+            return true;
+        }
+    }
+
+    /**
+     * @inheritdoc
+     */
+    protected function deleteValue($key)
+    {
+        unset($this->_cache[$key]);
+        return true;
+    }
+
+    /**
+     * @inheritdoc
+     */
+    protected function flushValues()
+    {
+        $this->_cache = [];
+        return true;
+    }
+}