[dns] Add Resolver\Factory::createCached

Author: igorw

Resolver/Factory.php

@@ -3,6 +3,8 @@
 namespace React\Dns\Resolver;
 
 use React\Dns\Query\Executor;
+use React\Dns\Query\CachedExecutor;
+use React\Dns\Query\RecordCache;
 use React\Dns\Protocol\Parser;
 use React\Dns\Protocol\BinaryDumper;
 use React\EventLoop\LoopInterface;
@@ -12,11 +14,29 @@ class Factory
     public function create($nameserver, LoopInterface $loop)
     {
         $nameserver = $this->addPortToServerIfMissing($nameserver);
-        $executor = new Executor($loop, new Parser(), new BinaryDumper());
+        $executor = $this->createExecutor($nameserver, $loop);
 
         return new Resolver($nameserver, $executor);
     }
 
+    public function createCached($nameserver, LoopInterface $loop)
+    {
+        $nameserver = $this->addPortToServerIfMissing($nameserver);
+        $executor = $this->createCachedExecutor($nameserver, $loop);
+
+        return new Resolver($nameserver, $executor);
+    }
+
+    protected function createExecutor($nameserver, LoopInterface $loop)
+    {
+        return new Executor($loop, new Parser(), new BinaryDumper());
+    }
+
+    protected function createCachedExecutor($nameserver, LoopInterface $loop)
+    {
+        return new CachedExecutor($this->createExecutor(), new RecordCache());
+    }
+
     protected function addPortToServerIfMissing($nameserver)
     {
         return false === strpos($nameserver, ':') ? "$nameserver:53" : $nameserver;