From 8fdf82f8a2854fae6c609a4a7255de84aeb25f65 Mon Sep 17 00:00:00 2001
From: postmannen <postmannen@gmail.com>
Date: Wed, 10 Mar 2021 14:14:09 +0100
Subject: [PATCH] named type procFunc

---
 process.go          | 13 +++++++++++--
 processesToStart.go | 36 ++++++++++++++++++++----------------
 2 files changed, 31 insertions(+), 18 deletions(-)

diff --git a/process.go b/process.go
index 3bff036..77bb2d9 100644
--- a/process.go
+++ b/process.go
@@ -40,13 +40,12 @@ type process struct {
 	allowedReceivers map[node]struct{}
 	// methodsAvailable
 	methodsAvailable MethodsAvailable
-	// TESTING:
 	// Helper or service function that can do some kind of work
 	// for the process.
 	// The idea is that this can hold for example the map of the
 	// the hello nodes to limit shared resources in the system as
 	// a whole for sharing a map from the *server level.
-	procFunc func() error
+	procFunc procFunc
 	// The channel to send a messages to the procFunc go routine.
 	// This is typically used within the methodHandler.
 	procFuncCh chan Message
@@ -86,6 +85,16 @@ func newProcess(processes *processes, newMessagesCh chan<- []subjectAndMessage,
 	return proc
 }
 
+// procFunc is a helper function that will do some extra work for
+// a message received for a process. This allows us to ACK back
+// to the publisher that the message was received, but we can let
+// the processFunc keep on working.
+// This can also be used to wrap in other types which we want to
+// work with that come from the outside. An example can be handling
+// of metrics which the message have no notion of, but a procFunc
+// can have that wrapped in from when it was constructed.
+type procFunc func() error
+
 // The purpose of this function is to check if we should start a
 // publisher or subscriber process, where a process is a go routine
 // that will handle either sending or receiving messages on one
diff --git a/processesToStart.go b/processesToStart.go
index b79e593..8d00654 100644
--- a/processesToStart.go
+++ b/processesToStart.go
@@ -36,9 +36,10 @@ func (s *server) ProcessesStart() {
 		proc.procFunc = func() error {
 			sayHelloNodes := make(map[node]struct{})
 			for {
-				//fmt.Printf("-- DEBUG 4.1: procFunc %v, procFuncCh %v\n\n", proc.procFunc, proc.procFuncCh)
+				// Receive a copy of the message sent from the method handler.
 				m := <-proc.procFuncCh
 				fmt.Printf("--- DEBUG : procFunc call:kind=%v, Subject=%v, toNode=%v\n", proc.processKind, proc.subject, proc.subject.ToNode)
+
 				sayHelloNodes[m.FromNode] = struct{}{}
 
 				// update the prometheus metrics
@@ -70,28 +71,31 @@ func (s *server) ProcessesStart() {
 	// sending of say hello.
 	if s.configuration.PublisherServiceSayhello != 0 {
 		fmt.Printf("Starting SayHello Publisher: %#v\n", s.nodeName)
+
 		// TODO: Replace "central" name with variable below.
 		sub := newSubject(SayHello, EventNACK, "central")
 		proc := newProcess(s.processes, s.newMessagesCh, s.configuration, sub, s.errorKernel.errorCh, processKindPublisher, []node{}, nil)
 
-		proc.procFunc = func() error {
-			for {
-				fmt.Printf("--- DEBUG : procFunc call:kind=%v, Subject=%v, toNode=%v\n", proc.processKind, proc.subject, proc.subject.ToNode)
+		// Define the procFun to be used for the process.
+		proc.procFunc = procFunc(
+			func() error {
+				for {
+					fmt.Printf("--- DEBUG : procFunc call:kind=%v, Subject=%v, toNode=%v\n", proc.processKind, proc.subject, proc.subject.ToNode)
 
-				d := fmt.Sprintf("Hello from %v\n", s.nodeName)
+					d := fmt.Sprintf("Hello from %v\n", s.nodeName)
 
-				m := Message{
-					ToNode:   "central",
-					FromNode: node(s.nodeName),
-					Data:     []string{d},
-					Method:   SayHello,
+					m := Message{
+						ToNode:   "central",
+						FromNode: node(s.nodeName),
+						Data:     []string{d},
+						Method:   SayHello,
+					}
+
+					sam := createSAMfromMessage(m)
+					proc.newMessagesCh <- []subjectAndMessage{sam}
+					time.Sleep(time.Second * time.Duration(s.configuration.PublisherServiceSayhello))
 				}
-
-				sam := createSAMfromMessage(m)
-				proc.newMessagesCh <- []subjectAndMessage{sam}
-				time.Sleep(time.Second * time.Duration(s.configuration.PublisherServiceSayhello))
-			}
-		}
+			})
 		go proc.spawnWorker(s)
 	}
 }