Merge pull request #3768 from nats-io/neil/sublistptrs

Deduplicate `*subscription` in `Sublist`

Author: derekcollison

server/sublist.go

@@ -84,8 +84,8 @@ type notifyMaps struct {
 // A node contains subscriptions and a pointer to the next level.
 type node struct {
 	next  *level
-	psubs map[*subscription]*subscription
-	qsubs map[string](map[*subscription]*subscription)
+	psubs map[*subscription]struct{}
+	qsubs map[string]map[*subscription]struct{}
 	plist []*subscription
 }
 
@@ -98,7 +98,7 @@ type level struct {
 
 // Create a new default node.
 func newNode() *node {
-	return &node{psubs: make(map[*subscription]*subscription)}
+	return &node{psubs: make(map[*subscription]struct{})}
 }
 
 // Create a new default level.
@@ -413,30 +413,30 @@ func (s *Sublist) Insert(sub *subscription) error {
 		l = n.next
 	}
 	if sub.queue == nil {
-		n.psubs[sub] = sub
+		n.psubs[sub] = struct{}{}
 		isnew = len(n.psubs) == 1
 		if n.plist != nil {
 			n.plist = append(n.plist, sub)
 		} else if len(n.psubs) > plistMin {
 			n.plist = make([]*subscription, 0, len(n.psubs))
 			// Populate
-			for _, psub := range n.psubs {
+			for psub := range n.psubs {
 				n.plist = append(n.plist, psub)
 			}
 		}
 	} else {
 		if n.qsubs == nil {
-			n.qsubs = make(map[string]map[*subscription]*subscription)
+			n.qsubs = make(map[string]map[*subscription]struct{})
 		}
 		qname := string(sub.queue)
 		// This is a queue subscription
 		subs, ok := n.qsubs[qname]
 		if !ok {
-			subs = make(map[*subscription]*subscription)
+			subs = make(map[*subscription]struct{})
 			n.qsubs[qname] = subs
 			isnew = true
 		}
-		subs[sub] = sub
+		subs[sub] = struct{}{}
 	}
 
 	s.count++
@@ -636,7 +636,7 @@ func addNodeToResults(n *node, results *SublistResult) {
 	if n.plist != nil {
 		results.psubs = append(results.psubs, n.plist...)
 	} else {
-		for _, psub := range n.psubs {
+		for psub := range n.psubs {
 			results.psubs = append(results.psubs, psub)
 		}
 	}
@@ -652,7 +652,7 @@ func addNodeToResults(n *node, results *SublistResult) {
 			nqsub := make([]*subscription, 0, len(qr))
 			results.qsubs = append(results.qsubs, nqsub)
 		}
-		for _, sub := range qr {
+		for sub := range qr {
 			if isRemoteQSub(sub) {
 				ns := atomic.LoadInt32(&sub.qw)
 				// Shadow these subscriptions
@@ -1435,13 +1435,13 @@ func (s *Sublist) addNodeToSubs(n *node, subs *[]*subscription, includeLeafHubs
 			addLocalSub(sub, subs, includeLeafHubs)
 		}
 	} else {
-		for _, sub := range n.psubs {
+		for sub := range n.psubs {
 			addLocalSub(sub, subs, includeLeafHubs)
 		}
 	}
 	// Queue subscriptions
 	for _, qr := range n.qsubs {
-		for _, sub := range qr {
+		for sub := range qr {
 			addLocalSub(sub, subs, includeLeafHubs)
 		}
 	}
@@ -1481,13 +1481,13 @@ func (s *Sublist) addAllNodeToSubs(n *node, subs *[]*subscription) {
 	if n.plist != nil {
 		*subs = append(*subs, n.plist...)
 	} else {
-		for _, sub := range n.psubs {
+		for sub := range n.psubs {
 			*subs = append(*subs, sub)
 		}
 	}
 	// Queue subscriptions
 	for _, qr := range n.qsubs {
-		for _, sub := range qr {
+		for sub := range qr {
 			*subs = append(*subs, sub)
 		}
 	}