Add TagDependency. Up code from upstream.

src/Mindy/Cache/Cache.php

@@ -107,7 +107,7 @@ public function init()
      * @param mixed $key the key to be normalized
      * @return string the generated cache key
      */
-    protected function buildKey($key)
+    public function buildKey($key)
     {
         if (is_string($key)) {
             $key = ctype_alnum($key) && mb_strlen($key, '8bit') <= 32 ? $key : md5($key);

src/Mindy/Cache/TagDependency.php

@@ -0,0 +1,122 @@
+<?php
+
+/**
+ * All rights reserved.
+ *
+ * @author Falaleev Maxim
+ * @email max@studio107.ru
+ * @version 1.0
+ * @company Studio107
+ * @site http://studio107.ru
+ * @date 05/02/15 18:27
+ */
+
+namespace Mindy\Cache;
+
+/**
+ * @link http://www.yiiframework.com/
+ * @copyright Copyright (c) 2008 Yii Software LLC
+ * @license http://www.yiiframework.com/license/
+ */
+
+/**
+ * TagDependency associates a cached data item with one or multiple [[tags]].
+ *
+ * By calling [[invalidate()]], you can invalidate all cached data items that are associated with the specified tag name(s).
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @since 2.0
+ */
+class TagDependency extends Dependency
+{
+    /**
+     * @var string|array a list of tag names for this dependency. For a single tag, you may specify it as a string.
+     */
+    public $tags = [];
+
+
+    /**
+     * Generates the data needed to determine if dependency has been changed.
+     * This method does nothing in this class.
+     * @param Cache $cache the cache component that is currently evaluating this dependency
+     * @return mixed the data needed to determine if dependency has been changed.
+     */
+    protected function generateDependencyData($cache)
+    {
+        $timestamps = $this->getTimestamps($cache, (array) $this->tags);
+
+        $newKeys = [];
+        foreach ($timestamps as $key => $timestamp) {
+            if ($timestamp === false) {
+                $newKeys[] = $key;
+            }
+        }
+        if (!empty($newKeys)) {
+            $timestamps = array_merge($timestamps, $this->touchKeys($cache, $newKeys));
+        }
+
+        return $timestamps;
+    }
+
+    /**
+     * Performs the actual dependency checking.
+     * @param Cache $cache the cache component that is currently evaluating this dependency
+     * @return boolean whether the dependency is changed or not.
+     */
+    public function getHasChanged($cache)
+    {
+        $timestamps = $this->getTimestamps($cache, (array) $this->tags);
+        return $timestamps !== $this->data;
+    }
+
+    /**
+     * Invalidates all of the cached data items that are associated with any of the specified [[tags]].
+     * @param Cache $cache the cache component that caches the data items
+     * @param string|array $tags
+     */
+    public static function invalidate($cache, $tags)
+    {
+        $keys = [];
+        foreach ((array) $tags as $tag) {
+            $keys[] = $cache->buildKey([__CLASS__, $tag]);
+        }
+        static::touchKeys($cache, $keys);
+    }
+
+    /**
+     * Generates the timestamp for the specified cache keys.
+     * @param Cache $cache
+     * @param string[] $keys
+     * @return array the timestamp indexed by cache keys
+     */
+    protected static function touchKeys($cache, $keys)
+    {
+        $items = [];
+        $time = microtime();
+        foreach ($keys as $key) {
+            $items[$key] = $time;
+        }
+        $cache->mset($items);
+        return $items;
+    }
+
+    /**
+     * Returns the timestamps for the specified tags.
+     * @param Cache $cache
+     * @param string[] $tags
+     * @return array the timestamps indexed by the specified tags.
+     */
+    protected function getTimestamps($cache, $tags)
+    {
+        if (empty($tags)) {
+            return [];
+        }
+
+        $keys = [];
+        foreach ($tags as $tag) {
+            $keys[] = $cache->buildKey([__CLASS__, $tag]);
+        }
+
+        return $cache->mget($keys);
+    }
+}