grpc使用多个中间件的转换

package main

import (
	"context"
	"fmt"
	"log"
)


type UnaryHandler func(ctx context.Context, req interface{}) (interface{}, error)
type UnaryServerInterceptor func(ctx context.Context, req interface{}, handler UnaryHandler) (resp interface{}, err error)
func HelloInterceptor(ctx context.Context, req interface{}, handler UnaryHandler) (interface{}, error){
	log.Println("hello")
	resp, err := handler(ctx, req)
	log.Println("see you")
	return resp, err
}

func HelloInterceptor1(ctx context.Context, req interface{}, handler UnaryHandler) (interface{}, error){
	log.Println("hello1")
	resp, err := handler(ctx, req)
	log.Println("see you1")
	return resp, err
}
func ChainUnaryServer(interceptors ...UnaryServerInterceptor) UnaryServerInterceptor {
	n := len(interceptors)
	return func(ctx context.Context, req interface{}, handler UnaryHandler) (resp interface{}, err error) {
		chainer := func(currentInter UnaryServerInterceptor, currentHandler UnaryHandler) UnaryHandler {
			return func(currentCtx context.Context, currentReq interface{}) (interface{}, error) {
				return currentInter(currentCtx, currentReq, currentHandler)
			}
		}
		chainerHandler := handler
		for i := n - 1; i >= 0; i -- {
			chainerHandler = chainer(interceptors[i], chainerHandler)
		}
		return chainerHandler(ctx, req)
	}
}
func main() {
	interceptor := ChainUnaryServer(HelloInterceptor, HelloInterceptor1)
	i, err := interceptor(context.Background(), nil, func(ctx context.Context, req interface{}) (interface{}, error) {
		return nil, nil
	})
	if err != nil {
		return
	}
	fmt.Println(i)
}