From 1e198f4825286ab16d0daf8e4d72e3186c7cb762 Mon Sep 17 00:00:00 2001
From: Jakub Sztandera <kubuxu@protonmail.ch>
Date: Sun, 16 Jun 2019 19:06:16 +0200
Subject: [PATCH] Use slice instead of map

License: MIT
Signed-off-by: Jakub Sztandera <kubuxu@protonmail.ch>
---
 p2p/host/eventbus/basic.go | 29 +++++++++++++----------------
 1 file changed, 13 insertions(+), 16 deletions(-)

diff --git a/p2p/host/eventbus/basic.go b/p2p/host/eventbus/basic.go
index c5133ed7..9ebde0d2 100644
--- a/p2p/host/eventbus/basic.go
+++ b/p2p/host/eventbus/basic.go
@@ -89,10 +89,17 @@ func (b *bus) Subscribe(typedChan interface{}, opts ...SubOption) (c CancelFunc,
 	err = b.withNode(typ.Elem(), func(n *node) {
 		// when all subs are waiting on this channel, setting this to 1 doesn't
 		// really affect benchmarks
-		i := n.sub(refCh)
+		n.sub(refCh)
+
 		c = func() {
 			n.lk.Lock()
-			delete(n.sinks, i)
+			for i := 0; i < len(n.sinks); i++ {
+				if n.sinks[i] == refCh {
+					n.sinks[i] = n.sinks[len(n.sinks)-1]
+					n.sinks = n.sinks[:len(n.sinks)-1]
+					break
+				}
+			}
 			tryDrop := len(n.sinks) == 0 && n.nEmitters == 0
 			n.lk.Unlock()
 			if tryDrop {
@@ -143,30 +150,20 @@ type node struct {
 	// emitter ref count
 	nEmitters int32
 
-	// sink index counter
-	sinkC int
-
-	// TODO: we could make emit a bit faster by making this into an array, but
-	//  it doesn't seem needed for now
-	sinks map[int]reflect.Value
-
 	keepLast bool
 	last     reflect.Value
+
+	sinks []reflect.Value
 }
 
 func newNode(typ reflect.Type) *node {
 	return &node{
 		typ: typ,
-
-		sinks: map[int]reflect.Value{},
 	}
 }
 
-func (n *node) sub(outChan reflect.Value) int {
-	i := n.sinkC
-	n.sinkC++
-	n.sinks[i] = outChan
-	return i
+func (n *node) sub(outChan reflect.Value) {
+	n.sinks = append(n.sinks, outChan)
 }
 
 func (n *node) emit(event interface{}) {