feat(middleware): add process result state: middleware processed

Process results could be:

- `GoNext` (aka `false`): middleware did not affect the request,
  or still need to process by rest middlewares.
- `SkipRests`: middleware processed and should skip rest
  middlewares, but continue to process out of middleware.
- `Processed` (aka `true`): request handled by middleware
  completely.

Author: marjune163

src/middleware/main.go

@@ -2,4 +2,12 @@ package middleware
 
 import "net/http"
 
-type Middleware func(w http.ResponseWriter, r *http.Request, context *Context) (processed bool)
+type ProcessResult int
+
+const (
+	GoNext ProcessResult = iota
+	SkipRests
+	Processed
+)
+
+type Middleware func(w http.ResponseWriter, r *http.Request, context *Context) (result ProcessResult)

src/serverHandler/middleware.go

@@ -24,8 +24,11 @@ func (h *aliasHandler) postMiddleware(w http.ResponseWriter, r *http.Request, da
 	}
 
 	for i := range h.postMiddlewares {
-		if h.postMiddlewares[i](w, r, context) {
+		result := h.postMiddlewares[i](w, r, context)
+		if result == middleware.Processed {
 			return true
+		} else if result == middleware.SkipRests {
+			break
 		}
 	}
 

src/serverHandler/multiplexHandler.go

@@ -23,9 +23,11 @@ func (mux multiplexHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 			VhostReqPath:  r.URL.Path,
 		}
 		for i := range mux.preMiddlewares {
-			processed := mux.preMiddlewares[i](w, r, middlewareContext)
-			if processed {
+			processResult := mux.preMiddlewares[i](w, r, middlewareContext)
+			if processResult == middleware.Processed {
 				return
+			} else if processResult == middleware.SkipRests {
+				break
 			}
 		}
 	}