Allow for cache adapter injection

README.md

@@ -53,6 +53,21 @@ $loop->run();
 If the first call returns before the second, only one query will be executed.
 The second result will be served from cache.
 
+### Custom cache adapter
+
+By default, the above will use an in memory cache.
+
+You can also specify a custom cache implementing [`CacheInterface`](https://github.com/reactphp/cache) to handle the record cache instead:
+
+```php
+$cache = new React\Cache\ArrayCache();
+$loop = React\EventLoop\Factory::create();
+$factory = new React\Dns\Resolver\Factory();
+$dns = $factory->createCached('8.8.8.8', $loop, $cache);
+```
+
+See also the wiki for possible [cache implementations](https://github.com/reactphp/react/wiki/Users#cache-implementations).
+
 ## Install
 
 The recommended way to install this library is [through Composer](http://getcomposer.org).

src/Resolver/Factory.php

@@ -3,6 +3,7 @@
 namespace React\Dns\Resolver;
 
 use React\Cache\ArrayCache;
+use React\Cache\CacheInterface;
 use React\Dns\Query\Executor;
 use React\Dns\Query\CachedExecutor;
 use React\Dns\Query\RecordCache;
@@ -21,10 +22,14 @@ public function create($nameserver, LoopInterface $loop)
         return new Resolver($nameserver, $executor);
     }
 
-    public function createCached($nameserver, LoopInterface $loop)
+    public function createCached($nameserver, LoopInterface $loop, CacheInterface $cache = null)
     {
+        if (!($cache instanceof CacheInterface)) {
+            $cache = new ArrayCache();
+        }
+
         $nameserver = $this->addPortToServerIfMissing($nameserver);
-        $executor = $this->createCachedExecutor($loop);
+        $executor = $this->createCachedExecutor($loop, $cache);
 
         return new Resolver($nameserver, $executor);
     }
@@ -39,9 +44,9 @@ protected function createRetryExecutor(LoopInterface $loop)
         return new RetryExecutor($this->createExecutor($loop));
     }
 
-    protected function createCachedExecutor(LoopInterface $loop)
+    protected function createCachedExecutor(LoopInterface $loop, CacheInterface $cache)
     {
-        return new CachedExecutor($this->createRetryExecutor($loop), new RecordCache(new ArrayCache()));
+        return new CachedExecutor($this->createRetryExecutor($loop), new RecordCache($cache));
     }
 
     protected function addPortToServerIfMissing($nameserver)

tests/Resolver/FactoryTest.php

@@ -39,7 +39,30 @@ public function createCachedShouldCreateResolverWithCachedExecutor()
         $resolver = $factory->createCached('8.8.8.8:53', $loop);
 
         $this->assertInstanceOf('React\Dns\Resolver\Resolver', $resolver);
-        $this->assertInstanceOf('React\Dns\Query\CachedExecutor', $this->getResolverPrivateMemberValue($resolver, 'executor'));
+        $executor = $this->getResolverPrivateMemberValue($resolver, 'executor');
+        $this->assertInstanceOf('React\Dns\Query\CachedExecutor', $executor);
+        $recordCache = $this->getCachedExecutorPrivateMemberValue($executor, 'cache');
+        $recordCacheCache = $this->getRecordCachePrivateMemberValue($recordCache, 'cache');
+        $this->assertInstanceOf('React\Cache\CacheInterface', $recordCacheCache);
+        $this->assertInstanceOf('React\Cache\ArrayCache', $recordCacheCache);
+    }
+
+    /** @test */
+    public function createCachedShouldCreateResolverWithCachedExecutorWithCustomCache()
+    {
+        $cache = $this->getMock('React\Cache\CacheInterface');
+        $loop = $this->getMock('React\EventLoop\LoopInterface');
+
+        $factory = new Factory();
+        $resolver = $factory->createCached('8.8.8.8:53', $loop, $cache);
+
+        $this->assertInstanceOf('React\Dns\Resolver\Resolver', $resolver);
+        $executor = $this->getResolverPrivateMemberValue($resolver, 'executor');
+        $this->assertInstanceOf('React\Dns\Query\CachedExecutor', $executor);
+        $recordCache = $this->getCachedExecutorPrivateMemberValue($executor, 'cache');
+        $recordCacheCache = $this->getRecordCachePrivateMemberValue($recordCache, 'cache');
+        $this->assertInstanceOf('React\Cache\CacheInterface', $recordCacheCache);
+        $this->assertSame($cache, $recordCacheCache);
     }
 
     /**
@@ -75,4 +98,18 @@ private function getResolverPrivateMemberValue($resolver, $field)
         $reflector->setAccessible(true);
         return $reflector->getValue($resolver);
     }
+
+    private function getCachedExecutorPrivateMemberValue($resolver, $field)
+    {
+        $reflector = new \ReflectionProperty('React\Dns\Query\CachedExecutor', $field);
+        $reflector->setAccessible(true);
+        return $reflector->getValue($resolver);
+    }
+
+    private function getRecordCachePrivateMemberValue($resolver, $field)
+    {
+        $reflector = new \ReflectionProperty('React\Dns\Query\RecordCache', $field);
+        $reflector->setAccessible(true);
+        return $reflector->getValue($resolver);
+    }
 }