From 5d06aa2d4fd4d966e976b3a310f038fc898d626b Mon Sep 17 00:00:00 2001
From: vyzo <vyzo@hackzen.org>
Date: Wed, 12 Aug 2020 12:29:49 +0300
Subject: [PATCH] add api for dynamically setting and resetting topic score
 parameters

---
 score.go | 44 ++++++++++++++++++++++++++++++++++++++++++++
 topic.go | 39 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 83 insertions(+)

diff --git a/score.go b/score.go
index c5f97d67..c9688eec 100644
--- a/score.go
+++ b/score.go
@@ -182,6 +182,50 @@ func newPeerScore(params *PeerScoreParams) *peerScore {
 	}
 }
 
+// update interface
+func (ps *peerScore) SetTopicScoreParams(topic string, p *TopicScoreParams) error {
+	// Note: assumes that the topic score parameters have already been validated
+	ps.Lock()
+	defer ps.Unlock()
+
+	old, exist := ps.params.Topics[topic]
+	ps.params.Topics[topic] = p
+
+	if !exist {
+		return nil
+	}
+
+	// check to see if the counter Caps are being lowered; if that's the case we need to recap them
+	recap := false
+	if p.FirstMessageDeliveriesCap < old.FirstMessageDeliveriesCap {
+		recap = true
+	}
+	if p.MeshMessageDeliveriesCap < old.MeshMessageDeliveriesCap {
+		recap = true
+	}
+	if !recap {
+		return nil
+	}
+
+	// recap counters for topic
+	for _, pstats := range ps.peerStats {
+		tstats, ok := pstats.topics[topic]
+		if !ok {
+			continue
+		}
+
+		if tstats.firstMessageDeliveries > p.FirstMessageDeliveriesCap {
+			tstats.firstMessageDeliveries = p.FirstMessageDeliveriesCap
+		}
+
+		if tstats.meshMessageDeliveries > p.MeshMessageDeliveriesCap {
+			tstats.meshMessageDeliveries = p.MeshMessageDeliveriesCap
+		}
+	}
+
+	return nil
+}
+
 // router interface
 func (ps *peerScore) Start(gs *GossipSubRouter) {
 	if ps == nil {
diff --git a/topic.go b/topic.go
index f4b670be..cfdf088f 100644
--- a/topic.go
+++ b/topic.go
@@ -31,6 +31,45 @@ func (t *Topic) String() string {
 	return t.topic
 }
 
+// SetScoreParams sets the topic score parameters if the pubsub router supports peer
+// scoring
+func (t *Topic) SetScoreParams(p *TopicScoreParams) error {
+	t.mux.Lock()
+	defer t.mux.Unlock()
+
+	if t.closed {
+		return ErrTopicClosed
+	}
+
+	err := p.validate()
+	if err != nil {
+		return fmt.Errorf("invalid topic score parameters: %w", err)
+	}
+
+	result := make(chan error, 1)
+	select {
+	case t.p.eval <- func() {
+		gs, ok := t.p.rt.(*GossipSubRouter)
+		if !ok {
+			result <- fmt.Errorf("pubsub router is not gossipsub")
+			return
+		}
+
+		if gs.score == nil {
+			result <- fmt.Errorf("peer scoring is not enabled in router")
+			return
+		}
+
+		result <- gs.score.SetTopicScoreParams(t.topic, p)
+	}:
+		err = <-result
+		return err
+
+	case <-t.p.ctx.Done():
+		return t.p.ctx.Err()
+	}
+}
+
 // EventHandler creates a handle for topic specific events
 // Multiple event handlers may be created and will operate independently of each other
 func (t *Topic) EventHandler(opts ...TopicEventHandlerOpt) (*TopicEventHandler, error) {