From 562b1ab9b7364fa967571293d884892d1168138a Mon Sep 17 00:00:00 2001
From: Vasiliy Tolstov <v.tolstov@unistack.org>
Date: Fri, 7 Mar 2025 15:26:20 +0300
Subject: [PATCH] broker: simplify handler check
Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>
---
broker/broker.go | 2 +-
broker/subscriber.go | 85 ++++----------------------------------------
2 files changed, 7 insertions(+), 80 deletions(-)
diff --git a/broker/broker.go b/broker/broker.go
index 53b15d4e..3664433a 100644
--- a/broker/broker.go
+++ b/broker/broker.go
@@ -21,7 +21,7 @@ var (
// ErrInvalidMessage returns when invalid Message passed
ErrInvalidMessage = errors.New("invalid message")
// ErrInvalidHandler returns when subscriber passed to Subscribe
- ErrInvalidHandler = errors.New("invalid handler")
+ ErrInvalidHandler = errors.New("invalid handler, ony func(Message) error and func([]Message) error supported")
// DefaultGracefulTimeout
DefaultGracefulTimeout = 5 * time.Second
)
diff --git a/broker/subscriber.go b/broker/subscriber.go
index bdced69c..df6f58a8 100644
--- a/broker/subscriber.go
+++ b/broker/subscriber.go
@@ -1,87 +1,14 @@
package broker
-import (
- "fmt"
- "reflect"
- "unicode"
- "unicode/utf8"
-)
-
-const (
- messageSig = "func(broker.Message) error"
- messagesSig = "func([]broker.Message) error"
-)
-
-// Precompute the reflect type for error. Can't use error directly
-// because Typeof takes an empty interface value. This is annoying.
-var typeOfError = reflect.TypeOf((*error)(nil)).Elem()
-
-// Is this an exported - upper case - name?
-func isExported(name string) bool {
- r, _ := utf8.DecodeRuneInString(name)
- return unicode.IsUpper(r)
-}
-
-// Is this type exported or a builtin?
-func isExportedOrBuiltinType(t reflect.Type) bool {
- for t.Kind() == reflect.Ptr {
- t = t.Elem()
- }
- // PkgPath will be non-empty even for an exported type,
- // so we need to check the type name as well.
- return isExported(t.Name()) || t.PkgPath() == ""
-}
-
// IsValidHandler func signature
func IsValidHandler(sub interface{}) error {
- typ := reflect.TypeOf(sub)
- var argType reflect.Type
- switch typ.Kind() {
- case reflect.Func:
- name := "Func"
- switch typ.NumIn() {
- case 1:
- argType = typ.In(0)
- default:
- return fmt.Errorf("subscriber %v takes wrong number of args: %v required signature %s", name, typ.NumIn(), messageSig)
- }
- if !isExportedOrBuiltinType(argType) {
- return fmt.Errorf("subscriber %v argument type not exported: %v", name, argType)
- }
- if typ.NumOut() != 1 {
- return fmt.Errorf("subscriber %v has wrong number of return values: %v require signature %s",
- name, typ.NumOut(), messageSig)
- }
- if returnType := typ.Out(0); returnType != typeOfError {
- return fmt.Errorf("subscriber %v returns %v not error", name, returnType.String())
- }
+ switch sub.(type) {
default:
- hdlr := reflect.ValueOf(sub)
- name := reflect.Indirect(hdlr).Type().Name()
-
- for m := 0; m < typ.NumMethod(); m++ {
- method := typ.Method(m)
- switch method.Type.NumIn() {
- case 3:
- argType = method.Type.In(2)
- default:
- return fmt.Errorf("subscriber %v.%v takes wrong number of args: %v required signature %s",
- name, method.Name, method.Type.NumIn(), messageSig)
- }
-
- if !isExportedOrBuiltinType(argType) {
- return fmt.Errorf("%v argument type not exported: %v", name, argType)
- }
- if method.Type.NumOut() != 1 {
- return fmt.Errorf(
- "subscriber %v.%v has wrong number of return values: %v require signature %s",
- name, method.Name, method.Type.NumOut(), messageSig)
- }
- if returnType := method.Type.Out(0); returnType != typeOfError {
- return fmt.Errorf("subscriber %v.%v returns %v not error", name, method.Name, returnType.String())
- }
- }
+ return ErrInvalidHandler
+ case func(Message) error:
+ break
+ case func([]Message) error:
+ break
}
-
return nil
}