added handler to type process

process.go

@@ -96,6 +96,13 @@ type process struct {
 	// Process name
 	processName processName
 
+	// handler is used to directly attach a handler to a process upon
+	// creation of the process, like when a process is spawning a sub
+	// process like REQCopySrc do. If we're not spawning a sub process
+	// and it is a regular process the handler to use is found with the
+	// getHandler method
+	handler func(proc process, message Message, node string) ([]byte, error)
+
 	// startup holds the startup functions for starting up publisher
 	// or subscriber processes
 	startup *startup
@@ -514,16 +521,22 @@ func (p process) messageSubscriberHandler(natsConn *nats.Conn, thisNode string,
 
 	// Check for ACK type Event.
 	case p.subject.Event == EventACK:
+		// When spawning sub processes we can directly assign handlers to the process upon
+		// creation. We here check if a handler is already assigned, and if it is nil, we
+		// lookup and find the correct handler to use if available.
+		if p.handler == nil {
 			// Look up the method handler for the specified method.
 			mh, ok := p.methodsAvailable.CheckIfExists(message.Method)
+			p.handler = mh.handler
 			if !ok {
 				er := fmt.Errorf("error: subscriberHandler: no such method type: %v", p.subject.Event)
 				p.errorKernel.errSend(p, message, er)
 			}
+		}
 
 		//var err error
 
-		out := p.callHandler(message, mh, thisNode)
+		out := p.callHandler(message, thisNode)
 
 		// Send a confirmation message back to the publisher to ACK that the
 		// message was received by the subscriber. The reply should be sent
@@ -531,14 +544,21 @@ func (p process) messageSubscriberHandler(natsConn *nats.Conn, thisNode string,
 		natsConn.Publish(msg.Reply, out)
 
 	case p.subject.Event == EventNACK:
+		// When spawning sub processes we can directly assign handlers to the process upon
+		// creation. We here check if a handler is already assigned, and if it is nil, we
+		// lookup and find the correct handler to use if available.
+		if p.handler == nil {
+			// Look up the method handler for the specified method.
 			mh, ok := p.methodsAvailable.CheckIfExists(message.Method)
+			p.handler = mh.handler
 			if !ok {
-			er := fmt.Errorf("error: subscriberHandler: method type not available: %v", p.subject.Event)
+				er := fmt.Errorf("error: subscriberHandler: no such method type: %v", p.subject.Event)
 				p.errorKernel.errSend(p, message, er)
 			}
+		}
 
 		// We do not send reply messages for EventNACL, so we can discard the output.
-		_ = p.callHandler(message, mh, thisNode)
+		_ = p.callHandler(message, thisNode)
 
 	default:
 		er := fmt.Errorf("info: did not find that specific type of event: %#v", p.subject.Event)
@@ -550,14 +570,14 @@ func (p process) messageSubscriberHandler(natsConn *nats.Conn, thisNode string,
 // callHandler will call the handler for the Request type defined in the message.
 // If checking signatures and/or acl's are enabled the signatures they will be
 // verified, and if OK the handler is called.
-func (p process) callHandler(message Message, mh methodHandler, thisNode string) []byte {
+func (p process) callHandler(message Message, thisNode string) []byte {
 	out := []byte{}
 	var err error
 
 	switch p.verifySigOrAclFlag(message) {
 	case true:
 		log.Printf("info: subscriberHandler: doHandler=true: %v\n", true)
-		out, err = mh.handler(p, message, thisNode)
+		out, err = p.handler(p, message, thisNode)
 		if err != nil {
 			er := fmt.Errorf("error: subscriberHandler: handler method failed: %v", err)
 			p.errorKernel.errSend(p, message, er)

requests_copy.go

@@ -112,6 +112,9 @@ func (m methodREQCopySrc) handler(proc process, message Message, node string) ([
 		// and not directly within the handler.
 		copySrcSubProc.procFunc = copySrcProcFunc(copySrcSubProc, cia)
 
+		// assign a handler to the sub process
+		copySrcSubProc.handler = copySrcHandler(cia)
+
 		// The process will be killed when the context expires.
 		go copySrcSubProc.spawnWorker()
 
@@ -210,6 +213,9 @@ func (m methodREQCopyDst) handler(proc process, message Message, node string) ([
 		// and not directly within the handler.
 		copyDstSubProc.procFunc = copyDstProcFunc(copyDstSubProc, cia)
 
+		// assign a handler to the sub process
+		copyDstSubProc.handler = copyDstHandler(cia)
+
 		// The process will be killed when the context expires.
 		go copyDstSubProc.spawnWorker()
 
@@ -224,6 +230,35 @@ func (m methodREQCopyDst) handler(proc process, message Message, node string) ([
 	return ackMsg, nil
 }
 
+func copySrcHandler(cia copyInitialData) func(process, Message, string) ([]byte, error) {
+	h := func(proc process, message Message, node string) ([]byte, error) {
+		// HERE!
+		// We should receive a ready message generated by the procFunc of Dst.
+
+		select {
+		case <-proc.ctx.Done():
+			log.Printf(" * copySrcHandler ended: %v\n", proc.processName)
+		}
+
+		return nil, nil
+	}
+
+	return h
+}
+
+func copyDstHandler(cia copyInitialData) func(process, Message, string) ([]byte, error) {
+	h := func(proc process, message Message, node string) ([]byte, error) {
+		select {
+		case <-proc.ctx.Done():
+			log.Printf(" * copyDstHandler ended: %v\n", proc.processName)
+		}
+
+		return nil, nil
+	}
+
+	return h
+}
+
 func copySrcProcFunc(proc process, cia copyInitialData) func(context.Context, chan Message) error {
 	pf := func(ctx context.Context, procFuncCh chan Message) error {