Initial QSfera import

Server/pkg/service/grpc/handler/ratelimiter/ratelimiter.go

@@ -0,0 +1,39 @@
+package ratelimiter
+
+import (
+	"context"
+
+	"go-micro.dev/v4/errors"
+	"go-micro.dev/v4/server"
+)
+
+// NewHandlerWrapper creates a blocking server side rate limiter.
+func NewHandlerWrapper(limit int) server.HandlerWrapper {
+	if limit <= 0 {
+		return func(h server.HandlerFunc) server.HandlerFunc {
+			return h
+		}
+	}
+
+	token := make(chan struct{}, limit)
+	for i := 0; i < limit; i++ {
+		token <- struct{}{}
+	}
+
+	return func(h server.HandlerFunc) server.HandlerFunc {
+		return func(ctx context.Context, req server.Request, rsp any) error {
+			select {
+			case <-ctx.Done():
+				return ctx.Err()
+			case t := <-token:
+				defer func() {
+					token <- t
+				}()
+				return h(ctx, req, rsp)
+			default:
+				return errors.New("go.micro.server", "Rate limit exceeded", 429)
+			}
+
+		}
+	}
+}