Add implementation of PRESTO middleware.

presto/middleware.nim

@@ -0,0 +1,33 @@
+#
+#         REST API framework implementation
+#             (c) Copyright 2021-Present
+#         Status Research & Development GmbH
+#
+#              Licensed under either of
+#  Apache License, version 2.0, (LICENSE-APACHEv2)
+#              MIT license (LICENSE-MIT)
+
+{.push raises: [].}
+
+import chronos, chronos/apps/http/httpserver
+import route, servercommon, serverprivate
+export httpserver, servercommon, serverprivate
+
+proc new*(
+    t: typedesc[RestServerMiddlewareRef],
+    router: RestRouter,
+    errorHandler: RestRequestErrorHandler = nil): HttpServerMiddlewareRef =
+
+  proc middlewareCallback(
+      middleware: HttpServerMiddlewareRef,
+      request: RequestFence,
+      handler: HttpProcessCallback2): Future[HttpResponseRef] {.
+      async: (raises: [CancelledError], raw: true).} =
+    let restmw = RestServerMiddlewareRef(middleware)
+    restmw.nextHandler = handler
+    processRestRequest[RestServerMiddlewareRef](restmw, request)
+
+  let middleware =
+    RestServerMiddlewareRef(router: router, errorHandler: errorHandler,
+                            handler: middlewareCallback)
+  HttpServerMiddlewareRef(middleware)

presto/servercommon.nim

@@ -12,8 +12,8 @@
 import std/options
 import chronos, chronos/apps/http/httpserver
 import chronicles
-import common
-export chronicles, options
+import common, route
+export chronicles, options, httpserver
 
 chronicles.formatIt(HttpTable):
   var res = newSeq[string]()
@@ -45,3 +45,8 @@ type
     error: RestRequestError,
     request: HttpRequestRef): Future[HttpResponseRef] {.
       async: (raises: [CancelledError]).}
+
+  RestServerMiddlewareRef* = ref object of HttpServerMiddlewareRef
+    router*: RestRouter
+    errorHandler*: RestRequestErrorHandler
+    nextHandler*: HttpProcessCallback2