added cache pipelines

NzbDrone.Api/Extensions/Pipelines/IfModifiedPipeline.cs

@@ -0,0 +1,33 @@
+using Nancy;
+using Nancy.Bootstrapper;
+using NzbDrone.Api.Frontend;
+
+namespace NzbDrone.Api.Extensions.Pipelines
+{
+    public class IfModifiedPipeline : IRegisterNancyPipeline
+    {
+        private readonly ICacheableSpecification _cacheableSpecification;
+
+        public IfModifiedPipeline(ICacheableSpecification cacheableSpecification)
+        {
+            _cacheableSpecification = cacheableSpecification;
+        }
+
+        public void Register(IPipelines pipelines)
+        {
+            pipelines.BeforeRequest.AddItemToStartOfPipeline(Handle);
+        }
+
+        private Response Handle(NancyContext context)
+        {
+            if (_cacheableSpecification.IsCacheable(context) && context.Request.Headers.IfModifiedSince.HasValue)
+            {
+                var response = new Response { ContentType = MimeTypes.GetMimeType(context.Request.Path), StatusCode = HttpStatusCode.NotModified };
+                response.Headers.EnableCache();
+                return response;
+            }
+
+            return null;
+        }
+    }
+}