cacheSerializationResults

.gitignore

@@ -60,3 +60,4 @@ com_crashlytics_export_strings.xml
 crashlytics.properties
 crashlytics-build.properties
 fabric.properties
+.dart_tool

lib/src/serializer.dart

@@ -0,0 +1,24 @@
+import 'dart:async';
+import 'package:angel_framework/angel_framework.dart';
+
+/// A middleware that enables the caching of response serialization.
+///
+/// This can improve the performance of sending objects that are complex to serialize.
+///
+/// You can pass a [shouldCache] callback to determine which values should be cached.
+RequestHandler cacheSerializationResults(
+    {Duration timeout, FutureOr<bool> Function(RequestContext, ResponseContext, Object) shouldCache}) {
+  return (RequestContext req, ResponseContext res) async {
+    var oldSerializer = res.serializer;
+    var cache = <dynamic, String>{};
+    res.serializer = (value) {
+      if (shouldCache == null) {
+        return cache.putIfAbsent(value, () => oldSerializer(value));
+      }
+
+      return oldSerializer(value);
+    };
+
+    return true;
+  };
+}