Refactor Proxy with ImplementFunc to allow override impl

common/proxy/proxy.go

@@ -40,23 +40,47 @@ import (
 type Proxy struct {
 	rpc         common.RPCService
 	invoke      protocol.Invoker
-	callBack    interface{}
+	callback    interface{}
 	attachments map[string]string
-
-	once sync.Once
+	implement   ImplementFunc
+	once        sync.Once
 }
 
+type (
+	// ProxyOption a function to init Proxy with options
+	ProxyOption func(p *Proxy)
+	// ImplementFunc function for proxy impl of RPCService functions
+	ImplementFunc func(p *Proxy, v common.RPCService)
+)
+
 var (
 	typError = reflect.Zero(reflect.TypeOf((*error)(nil)).Elem()).Type()
 )
 
 // NewProxy create service proxy.
-func NewProxy(invoke protocol.Invoker, callBack interface{}, attachments map[string]string) *Proxy {
-	return &Proxy{
+func NewProxy(invoke protocol.Invoker, callback interface{}, attachments map[string]string) *Proxy {
+	return NewProxyWithOptions(invoke, callback, attachments,
+		WithProxyImplementFunc(DefaultProxyImplementFunc))
+}
+
+// NewProxyWithOptions create service proxy with options.
+func NewProxyWithOptions(invoke protocol.Invoker, callback interface{}, attachments map[string]string, opts ...ProxyOption) *Proxy {
+	p := &Proxy{
 		invoke:      invoke,
-		callBack:    callBack,
+		callback:    callback,
 		attachments: attachments,
 	}
+	for _, opt := range opts {
+		opt(p)
+	}
+	return p
+}
+
+// WithProxyImplementFunc an option function to setup proxy.ImplementFunc
+func WithProxyImplementFunc(f ImplementFunc) ProxyOption {
+	return func(p *Proxy) {
+		p.implement = f
+	}
 }
 
 // Implement
@@ -66,6 +90,29 @@ func NewProxy(invoke protocol.Invoker, callBack interface{}, attachments map[str
 //  		Yyy func(ctx context.Context, args []interface{}, rsp *Zzz) error
 // 		}
 func (p *Proxy) Implement(v common.RPCService) {
+	p.once.Do(func() {
+		p.implement(p, v)
+		p.rpc = v
+	})
+}
+
+// Get gets rpc service instance.
+func (p *Proxy) Get() common.RPCService {
+	return p.rpc
+}
+
+// GetCallback gets callback.
+func (p *Proxy) GetCallback() interface{} {
+	return p.callback
+}
+
+// GetInvoker gets Invoker.
+func (p *Proxy) GetInvoker() protocol.Invoker {
+	return p.invoke
+}
+
+// DefaultProxyImplementFunc the default function for proxy impl
+func DefaultProxyImplementFunc(p *Proxy, v common.RPCService) {
 	// check parameters, incoming interface must be a elem's pointer.
 	valueOf := reflect.ValueOf(v)
 	logger.Debugf("[Implement] reflect.TypeOf: %s", valueOf.String())
@@ -138,7 +185,7 @@ func (p *Proxy) Implement(v common.RPCService) {
 
 			inv = invocation_impl.NewRPCInvocationWithOptions(invocation_impl.WithMethodName(methodName),
 				invocation_impl.WithArguments(inIArr), invocation_impl.WithReply(reply.Interface()),
-				invocation_impl.WithCallBack(p.callBack), invocation_impl.WithParameterValues(inVArr))
+				invocation_impl.WithCallBack(p.callback), invocation_impl.WithParameterValues(inVArr))
 
 			for k, value := range p.attachments {
 				inv.SetAttachments(k, value)
@@ -215,23 +262,4 @@ func (p *Proxy) Implement(v common.RPCService) {
 		}
 	}
 
-	p.once.Do(func() {
-		p.rpc = v
-	})
-
-}
-
-// Get gets rpc service instance.
-func (p *Proxy) Get() common.RPCService {
-	return p.rpc
-}
-
-// GetCallback gets callback.
-func (p *Proxy) GetCallback() interface{} {
-	return p.callBack
-}
-
-// GetInvoker gets Invoker.
-func (p *Proxy) GetInvoker() protocol.Invoker {
-	return p.invoke
 }