Wildcard subscriptions

This commit is contained in:
bad 2021-10-08 23:53:37 +02:00
parent a4eaf5f8f7
commit 7cab972065
3 changed files with 117 additions and 55 deletions

View file

@ -159,30 +159,30 @@ func (s *Session) VisitConnect(_ packets.ConnectPacket) {
}
func (s *Session) VisitPublish(p packets.PublishPacket) {
subs, lock := subscription.Subscriptions.GetSubscriptions(p.TopicName)
defer lock.Unlock()
if p.QOSLevel == 0 {
if p.PacketId != nil {
log.Printf("Client: %v, Got publish with qos 0 and a packet id, ignoring\n", s.ClientID)
return
subNodes := subscription.Subscriptions.GetSubscriptions(p.TopicName)
for _, subNode := range subNodes {
subNode.NodeLock.RLock()
defer subNode.NodeLock.RUnlock()
if p.QOSLevel == 0 {
if p.PacketId != nil {
log.Printf("Client: %v, Got publish with qos 0 and a packet id, ignoring\n", s.ClientID)
return
}
} else if p.QOSLevel == 1 {
var reason packets.PubackReasonCode = packets.PubackReasonCodeSuccess
ack := packets.PubackPacket{
PacketID: *p.PacketId,
Reason: reason,
}
s.Connection.sendPacket(ack)
} else if p.QOSLevel == 2 {
panic("UNIMPLEMENTED QOS level 2")
}
} else if p.QOSLevel == 1 {
var reason packets.PubackReasonCode = packets.PubackReasonCodeSuccess
if len(subs) == 0 {
reason = packets.PubackReasonCodeNoMatchingSubscribers
}
ack := packets.PubackPacket{
PacketID: *p.PacketId,
Reason: reason,
}
s.Connection.sendPacket(ack)
} else if p.QOSLevel == 2 {
panic("UNIMPLEMENTED QOS level 2")
}
for _, sub := range subs {
if !(sub.NoLocal && sub.SubscriptionChannel == s.SubscriptionChannel) {
go func(sub subscription.Subscription) { sub.SubscriptionChannel <- p }(sub)
for _, sub := range subNode.Subscriptions {
if !(sub.NoLocal && sub.SubscriptionChannel == s.SubscriptionChannel) {
go func(sub subscription.Subscription) { sub.SubscriptionChannel <- p }(sub)
}
}
}
}

View file

@ -19,9 +19,9 @@ type Subscription struct {
}
type SubscriptionTreeNode struct {
subscriptions []Subscription
children map[string]*SubscriptionTreeNode
nodeLock sync.RWMutex
Subscriptions []Subscription
NodeLock sync.RWMutex
}
func newSubscriptionTreeNode() *SubscriptionTreeNode {
@ -37,34 +37,36 @@ func (s *SubscriptionTreeNode) findNode(fields []string) *SubscriptionTreeNode {
field := fields[0]
s.nodeLock.RLock()
s.NodeLock.RLock()
_, exists := s.children[field]
// Insert a value into the map if one doesn't exist yet
if !exists {
// Can't upgrade a read lock so we need to unlock and
// check again, this time with a write lock
s.nodeLock.RUnlock()
s.nodeLock.Lock()
s.NodeLock.RUnlock()
s.NodeLock.Lock()
_, exists = s.children[field]
if !exists {
s.children[field] = newSubscriptionTreeNode()
}
s.nodeLock.Unlock()
s.nodeLock.RLock()
s.NodeLock.Unlock()
s.NodeLock.RLock()
}
child, _ := s.children[field]
s.nodeLock.RUnlock()
s.NodeLock.RUnlock()
return child.findNode(fields[1:])
}
func (s *SubscriptionTreeNode) removeSubscription(subChan SubscriptionChannel) {
for i, sub := range s.subscriptions {
for i, sub := range s.Subscriptions {
if sub.SubscriptionChannel == subChan {
lst := len(s.subscriptions) - 1
s.subscriptions[i] = s.subscriptions[lst]
s.subscriptions = s.subscriptions[:lst]
lst := len(s.Subscriptions) - 1
s.Subscriptions[i] = s.Subscriptions[lst]
s.Subscriptions = s.Subscriptions[:lst]
}
}
}
@ -73,34 +75,64 @@ func (s *SubscriptionTreeNode) Subscribe(topicFilter packets.TopicFilter, subCha
sub := Subscription{subChan, topicFilter}
node := s.findNode(topicFilter.Topic.Fields)
node.nodeLock.Lock()
node.subscriptions = append(node.subscriptions, sub)
node.nodeLock.Unlock()
node.NodeLock.Lock()
node.Subscriptions = append(node.Subscriptions, sub)
node.NodeLock.Unlock()
}
func (s *SubscriptionTreeNode) Unsubscribe(topic packets.Topic, subChan SubscriptionChannel) {
node := s.findNode(topic.Fields)
node.nodeLock.Lock()
node.NodeLock.Lock()
node.removeSubscription(subChan)
node.nodeLock.Unlock()
node.NodeLock.Unlock()
}
func (s *SubscriptionTreeNode) RemoveSubsForChannel(subChan SubscriptionChannel) {
for _, node := range s.children {
node.nodeLock.Lock()
node.NodeLock.Lock()
node.removeSubscription(subChan)
node.nodeLock.Unlock()
node.NodeLock.Unlock()
node.RemoveSubsForChannel(subChan)
}
}
func (s *SubscriptionTreeNode) GetSubscriptions(topicName string) ([]Subscription, sync.Locker) {
// Returns the subscriptions whose filters match the given topic name
func (s *SubscriptionTreeNode) GetSubscriptions(topicName string) []*SubscriptionTreeNode {
fields := strings.Split(topicName, "/")
child := s.findNode(fields)
locker := child.nodeLock.RLocker()
locker.Lock()
return child.subscriptions, locker
return s.matchSubscriptions(fields)
}
// Returns nodes with subscriptions that match the given topic
func (s *SubscriptionTreeNode) matchSubscriptions(fields []string) []*SubscriptionTreeNode {
if len(fields) == 0 {
return []*SubscriptionTreeNode{s}
}
sub := make([]*SubscriptionTreeNode, 0)
s.NodeLock.RLock()
// Single level wildcard(+)
if SlWildcard, exists := s.children["+"]; exists {
sub = append(sub, SlWildcard.matchSubscriptions(fields[1:])...)
}
// Multi level wildcard(#)
if MlWildcard, exists := s.children["#"]; exists {
sub = append(sub, MlWildcard)
}
field := fields[0]
if field == "#" || field == "+" {
// TODO handle gracefully
panic("Wildcard in topic")
}
if child, exists := s.children[field]; exists {
sub = append(sub, child.matchSubscriptions(fields[1:])...)
}
s.NodeLock.RUnlock()
return sub
}

View file

@ -6,22 +6,52 @@ import (
"badat.dev/maeqtt/v2/mqtt/packets"
)
func TestSubscribe(t *testing.T) {
func assertMatches(topic packets.Topic, topicName string, shouldMatch bool, t *testing.T) {
tree := newSubscriptionTreeNode()
topic, _ := packets.ParseTopic("a/b/c")
channel := make(SubscriptionChannel)
topicFilter := packets.TopicFilter{
Topic: topic,
MaxQoS: 1,
}
tree.Subscribe(topicFilter, channel)
subs, lock := tree.GetSubscriptions("a/b/c")
defer lock.Unlock()
subs := tree.GetSubscriptions(topicName)
if len(subs) != 1 {
t.Errorf("Error storing subscriptions, expected to len(subs) to be 1, got: %v \n", len(subs))
if (len(subs) != 1) && shouldMatch {
t.Errorf("Topic %v did not match %v", topic, topicName)
}
if subs[0].MaxQoS != topicFilter.MaxQoS || subs[0].SubscriptionChannel != channel {
t.Error("Error with data stored in a subscription")
if (len(subs) == 1) && !shouldMatch {
t.Errorf("Topic %v matched %v (it wasn't supposed to)", topic, topicName )
}
}
func TestSubscribe(t *testing.T) {
topic, _ := packets.ParseTopic("a/b/c")
assertMatches(topic, "a/b/c", true, t)
assertMatches(topic, "a/c/c", false, t)
assertMatches(topic, "b/b/c", false, t)
assertMatches(topic, "aaa/c/a", false, t)
}
func TestSingleLevelWildcard(t *testing.T) {
topic, _ := packets.ParseTopic("a/+/c")
assertMatches(topic, "a/b/c", true, t)
assertMatches(topic, "a/c/c", true, t)
assertMatches(topic, "a/b/d", false, t)
assertMatches(topic, "aaa/c/a", false, t)
topic, _ = packets.ParseTopic("+/+/+")
assertMatches(topic, "a/b/c", true, t)
assertMatches(topic, "a/c/c", true, t)
assertMatches(topic, "a/b/d/e", false, t)
assertMatches(topic, "c/a", true, t)
}
func TestMultiLevelWildcard(t *testing.T) {
topic, _ := packets.ParseTopic("a/b/c/#")
assertMatches(topic, "a/b/c", true, t)
assertMatches(topic, "a/b/c/a", true, t)
assertMatches(topic, "a/b/c/d", true, t)
assertMatches(topic, "a/b/c/f", true, t)
assertMatches(topic, "a/b/d/a", false, t)
}