rewrote the recipes about APC and opcache to avoid deprecation notices

doc/recipes.rst

@@ -337,25 +337,52 @@ Refreshing modified Templates when OPcache or APC is enabled
 
 When using OPcache with ``opcache.validate_timestamps`` set to ``0`` or APC
 with ``apc.stat`` set to ``0`` and Twig cache enabled, clearing the template
-cache won't update the cache. To get around this, one can extend
+cache won't update the cache.
-``Twig_Environment`` and force the update of the cache when Twig rewrites the
-cache::
 
-    class Twig_Environment_APC extends Twig_Environment
+To get around this, create a custom ``Twig_Cache_Interface`` implementation and
+force the update of the cache when Twig rewrites the cache::
+
+    class OpCacheAwareCacheFilesystem extends Twig_Cache_Filesystem
     {
-        protected function writeCacheFile($file, $content)
+        public function write($key, $content)
         {
-            parent::writeCacheFile($file, $content);
+            parent::write($key, $content);
 
             // Compile cached file into bytecode cache
-            if (extension_loaded('Zend OPcache') && ini_get('opcache.enable')) {
+            if (function_exists('opcache_invalidate') && ini_get('opcache.enable')) {
-                opcache_invalidate($file);
+                opcache_invalidate($key);
-            } elseif (extension_loaded('apc') && ini_get('apc.enabled')) {
+            } elseif (function_exists('apc_compile_file') && ini_get('apc.enabled')) {
-                apc_compile_file($file);
+                apc_compile_file($key);
             }
         }
     }
 
+Then, use that new class as the template cache::
+
+    $twig = new Twig_Environment($loader, array(
+        'cache' => new OpCacheAwareCacheFilesystem('/some/cache/path'),
+        // ...
+    ));
+
+.. note::
+
+    Before Twig 1.22, you should extend ``Twig_Environment`` instead::
+
+        class OpCacheAwareTwigEnvironment extends Twig_Environment
+        {
+            protected function writeCacheFile($file, $content)
+            {
+                parent::writeCacheFile($file, $content);
+
+                // Compile cached file into bytecode cache
+                if (function_exists('opcache_invalidate') && ini_get('opcache.enable')) {
+                    opcache_invalidate($file);
+                } elseif (function_exists('apc_compile_file') && ini_get('apc.enabled')) {
+                    apc_compile_file($file);
+                }
+            }
+        }
+
 Reusing a stateful Node Visitor
 -------------------------------