created hws module

hws/middleware_timer.go

@@ -0,0 +1,33 @@
+package hws
+
+import (
+	"context"
+	"errors"
+	"net/http"
+	"time"
+)
+
+func startTimer(next http.Handler) http.Handler {
+	return http.HandlerFunc(
+		func(w http.ResponseWriter, r *http.Request) {
+			start := time.Now()
+			ctx := setStart(r.Context(), start)
+			newReq := r.WithContext(ctx)
+			next.ServeHTTP(w, newReq)
+		},
+	)
+}
+
+// Set the start time of the request
+func setStart(ctx context.Context, time time.Time) context.Context {
+	return context.WithValue(ctx, "hws context key request-timer", time)
+}
+
+// Get the start time of the request
+func getStartTime(ctx context.Context) (time.Time, error) {
+	start, ok := ctx.Value("hws context key request-timer").(time.Time)
+	if !ok {
+		return time.Time{}, errors.New("Failed to get start time of request")
+	}
+	return start, nil
+}