redis驱动添加handler方法，暴露对象以调用高级方法

library/think/cache/driver/Redis.php

@@ -115,4 +115,14 @@ class Redis
         return $this->handler->flushDB();
     }
 
+    /**
+     * 返回句柄对象，可执行其它高级方法
+     *
+     * @access public
+     * @return object
+     */
+    public function handler()
+    {
+        return $this->handler;
+    }
 }

tests/thinkphp/library/think/cache/driver/redisTest.php

@@ -47,6 +47,17 @@ class redisTest extends cacheTestCase
 
     public function testStoreSpecialValues()
     {
+        $redis = new \think\cache\driver\Redis(['length' => 3]);
+        $redis->set('key', 'value');
+        $redis->get('key');
+
+        $redis->handler()->setnx('key', 'value');
+        $value = $redis->handler()->get('key');
+        $this->assertEquals('value', $value);
+        
+        $redis->handler()->hset('hash', 'key', 'value');
+        $value = $redis->handler()->hget('hash', 'key');
+        $this->assertEquals('value', $value);
     }
 
     public function testExpire()