interceptor.go

// Copyright (c) 2016 Wothing Co., Ltd. All rights reserved.

package worpc

import (
	"golang.org/x/net/context"
	"google.golang.org/grpc"
)

// UnaryInterceptorChain build the multi interceptors into one interceptor chain.
func UnaryInterceptorChain(interceptors ...grpc.UnaryServerInterceptor) grpc.UnaryServerInterceptor {
	return func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (resp interface{}, err error) {
		chain := handler
		for i := len(interceptors) - 1; i >= 0; i-- {
			chain = build(interceptors[i], chain, info)
		}
		return chain(ctx, req)
	}
}

// build is the interceptor chain helper
func build(c grpc.UnaryServerInterceptor, n grpc.UnaryHandler, info *grpc.UnaryServerInfo) grpc.UnaryHandler {
	return func(ctx context.Context, req interface{}) (interface{}, error) {
		return c(ctx, req, info, n)
	}
}