Added YiiCache adapter

Author: creocoder

src/YiiCache.php

@@ -0,0 +1,64 @@
+<?php
+/**
+ * @link https://github.com/creocoder/yii2-flysystem
+ * @copyright Copyright (c) 2015 Alexander Kochetov
+ * @license http://opensource.org/licenses/BSD-3-Clause
+ */
+
+namespace creocoder\flysystem;
+
+use League\Flysystem\Cached\Storage\AbstractCache;
+use yii\caching\Cache;
+
+/**
+ * YiiCache
+ *
+ * @author Alexander Kochetov <[email protected]>
+ */
+class YiiCache extends AbstractCache
+{
+    /**
+     * @var Cache
+     */
+    protected $yiiCache;
+    /**
+     * @var string
+     */
+    protected $key;
+    /**
+     * @var integer
+     */
+    protected $duration;
+
+    /**
+     * @param Cache $yiiCache
+     * @param string $key
+     * @param integer $duration
+     */
+    public function __construct(Cache $yiiCache, $key = 'flysystem', $duration = 0)
+    {
+        $this->yiiCache = $yiiCache;
+        $this->key = $key;
+        $this->duration = $duration;
+    }
+
+    /**
+     * @inheritdoc
+     */
+    public function load()
+    {
+        $contents = $this->yiiCache->get($this->key);
+
+        if ($contents !== false) {
+            $this->setFromStorage($contents);
+        }
+    }
+
+    /**
+     * @inheritdoc
+     */
+    public function save()
+    {
+        $this->yiiCache->set($this->key, $this->getForStorage(), $this->duration);
+    }
+}