[fanout] Optimize fanout

messaging/fanout.go

@@ -22,21 +22,21 @@ type Pipeline struct {
 	chain   chan interface{}
 }
 
-func (p *Pipeline) Start() {
+func (p *Pipeline) Start(ctx context.Context) {
 	go func(pipe *Pipeline) {
 		for {
-			expectationWorkers := len(pipe.chain)
-			if expectationWorkers > MaxWorkers {
-				expectationWorkers = expectationWorkers % MaxWorkers
+			expectationWorkers := len(pipe.chain) % MaxWorkers
+			if expectationWorkers >= MaxWorkers {
+				expectationWorkers = 0
 			}
-			for _, c := range pipe.workers {
-				if expectationWorkers < int(c.index) {
-					break
-				}
-				select {
-				case val := <-pipe.chain:
-					go c.stream(val)
+			select {
+			case <-ctx.Done():
+				return
+			case val, ok := <-pipe.chain:
+				if !ok {
+					return
 				}
+				go pipe.workers[expectationWorkers].stream(val)
 			}
 		}
 	}(p)