From d153cdf4e0c7ff540d56ad101286c236f06379de Mon Sep 17 00:00:00 2001
From: Kamil Kloch <kamilkloch@users.noreply.github.com>
Date: Thu, 10 Aug 2023 09:15:36 +0200
Subject: [PATCH] Server interpreter optimizations. (#3076)

Co-authored-by: Kamil Kloch <kamil.kloch@superfund-technologies.com>
---
 .../interpreter/ServerInterpreter.scala       | 44 ++++++++++---------
 1 file changed, 24 insertions(+), 20 deletions(-)

diff --git a/server/core/src/main/scala/sttp/tapir/server/interpreter/ServerInterpreter.scala b/server/core/src/main/scala/sttp/tapir/server/interpreter/ServerInterpreter.scala
index ba9b0a0579..1689d01d05 100644
--- a/server/core/src/main/scala/sttp/tapir/server/interpreter/ServerInterpreter.scala
+++ b/server/core/src/main/scala/sttp/tapir/server/interpreter/ServerInterpreter.scala
@@ -29,12 +29,14 @@ class ServerInterpreter[R, F[_], B, S](
   ): RequestHandler[F, R, B] = {
     is match {
       case Nil => RequestHandler.from { (request, ses, _) => firstNotNone(request, ses, eisAcc.reverse, Nil) }
-      case (i: RequestInterceptor[F]) :: tail =>
-        i(
-          responder,
-          { ei => RequestHandler.from { (request, ses, _) => callInterceptors(tail, ei :: eisAcc, responder).apply(request, ses) } }
-        )
-      case (ei: EndpointInterceptor[F]) :: tail => callInterceptors(tail, ei :: eisAcc, responder)
+      case is => is.head match {
+        case ei: EndpointInterceptor[F] => callInterceptors(is.tail, ei :: eisAcc, responder)
+        case i: RequestInterceptor[F] =>
+          i(
+            responder,
+            { ei => RequestHandler.from { (request, ses, _) => callInterceptors(is.tail, ei :: eisAcc, responder).apply(request, ses) } }
+          )
+      }
     }
   }
 
@@ -47,7 +49,8 @@ class ServerInterpreter[R, F[_], B, S](
   ): F[RequestResult[B]] =
     ses match {
       case Nil => (RequestResult.Failure(accumulatedFailureContexts.reverse): RequestResult[B]).unit
-      case se :: tail =>
+      case ses =>
+        val se = ses.head
         tryServerEndpoint[se.SECURITY_INPUT, se.PRINCIPAL, se.INPUT, se.ERROR_OUTPUT, se.OUTPUT](
           request,
           se,
@@ -55,28 +58,29 @@ class ServerInterpreter[R, F[_], B, S](
         )
           .flatMap {
             case RequestResult.Failure(failureContexts) =>
-              firstNotNone(request, tail, endpointInterceptors, failureContexts ++: accumulatedFailureContexts)
+              firstNotNone(request, ses.tail, endpointInterceptors, failureContexts ++: accumulatedFailureContexts)
             case r => r.unit
           }
     }
 
-  private def tryServerEndpoint[A, U, I, E, O](
-      request: ServerRequest,
-      se: ServerEndpoint.Full[A, U, I, E, O, R, F],
-      endpointInterceptors: List[EndpointInterceptor[F]]
-  ): F[RequestResult[B]] = {
-    val defaultSecurityFailureResponse =
+  private val defaultSecurityFailureResponse =
       ServerResponse[B](StatusCode.InternalServerError, Nil, None, None).unit
 
-    def endpointHandler(securityFailureResponse: => F[ServerResponse[B]]): EndpointHandler[F, B] =
+  private def endpointHandler(securityFailureResponse: => F[ServerResponse[B]], endpointInterceptors: List[EndpointInterceptor[F]]): EndpointHandler[F, B] =
       endpointInterceptors.foldRight(defaultEndpointHandler(securityFailureResponse)) { case (interceptor, handler) =>
         interceptor(responder(defaultSuccessStatusCode), handler)
       }
 
-    def resultOrValueFrom = new ResultOrValueFrom {
+  private def tryServerEndpoint[A, U, I, E, O](
+      request: ServerRequest,
+      se: ServerEndpoint.Full[A, U, I, E, O, R, F],
+      endpointInterceptors: List[EndpointInterceptor[F]]
+  ): F[RequestResult[B]] = {
+
+    val resultOrValueFrom = new ResultOrValueFrom {
       def onDecodeFailure(input: EndpointInput[_], failure: DecodeResult.Failure): F[RequestResult[B]] = {
         val decodeFailureContext = interceptor.DecodeFailureContext(se.endpoint, input, failure, request)
-        endpointHandler(defaultSecurityFailureResponse)
+        endpointHandler(defaultSecurityFailureResponse, endpointInterceptors)
           .onDecodeFailure(decodeFailureContext)
           .map {
             case Some(response) => RequestResult.Response(response)
@@ -105,7 +109,7 @@ class ServerInterpreter[R, F[_], B, S](
       // 4. running the security logic
       securityLogicResult <- ResultOrValue(
         se.securityLogic(monad)(a).map(Right(_): Either[RequestResult[B], Either[E, U]]).handleError { case t: Throwable =>
-          endpointHandler(monad.error(t))
+          endpointHandler(monad.error(t), endpointInterceptors)
             .onSecurityFailure(SecurityFailureContext(se, a, request))
             .map(r => Left(RequestResult.Response(r)): Either[RequestResult[B], Either[E, U]])
         }
@@ -113,7 +117,7 @@ class ServerInterpreter[R, F[_], B, S](
       response <- securityLogicResult match {
         case Left(e) =>
           resultOrValueFrom.value(
-            endpointHandler(responder(defaultErrorStatusCode)(request, model.ValuedEndpointOutput(se.endpoint.errorOutput, e)))
+            endpointHandler(responder(defaultErrorStatusCode)(request, model.ValuedEndpointOutput(se.endpoint.errorOutput, e)), endpointInterceptors)
               .onSecurityFailure(SecurityFailureContext(se, a, request))
               .map(r => RequestResult.Response(r): RequestResult[B])
           )
@@ -124,7 +128,7 @@ class ServerInterpreter[R, F[_], B, S](
             values <- resultOrValueFrom(decodeBody(request, inputValues))
             params <- resultOrValueFrom(InputValue(se.endpoint.input, values))
             response <- resultOrValueFrom.value(
-              endpointHandler(defaultSecurityFailureResponse)
+              endpointHandler(defaultSecurityFailureResponse, endpointInterceptors)
                 .onDecodeSuccess(interceptor.DecodeSuccessContext(se, a, u, params.asAny.asInstanceOf[I], request))
                 .map(r => RequestResult.Response(r): RequestResult[B])
             )