expose internalTracer as RawTracer

gossip_tracer.go

@@ -111,7 +111,7 @@ func (gt *gossipTracer) GetBrokenPromises() map[peer.ID]int {
 	return res
 }
 
-var _ internalTracer = (*gossipTracer)(nil)
+var _ RawTracer = (*gossipTracer)(nil)
 
 func (gt *gossipTracer) fulfillPromise(msg *Message) {
 	mid := gt.msgID(msg.Message)

gossipsub.go

@@ -196,8 +196,8 @@ func NewGossipSub(ctx context.Context, h host.Host, opts ...Option) (*PubSub, er
 		tagTracer: newTagTracer(h.ConnManager()),
 	}
 
-	// use the withInternalTracer option to hook up the tag tracer
-	opts = append(opts, withInternalTracer(rt.tagTracer))
+	// hook the tag tracer
+	opts = append(opts, WithRawTracer(rt.tagTracer))
 	return NewPubSub(ctx, h, rt, opts...)
 }
 
@@ -232,12 +232,12 @@ func WithPeerScore(params *PeerScoreParams, thresholds *PeerScoreThresholds) Opt
 
 		// hook the tracer
 		if ps.tracer != nil {
-			ps.tracer.internal = append(ps.tracer.internal, gs.score, gs.gossipTracer)
+			ps.tracer.raw = append(ps.tracer.raw, gs.score, gs.gossipTracer)
 		} else {
 			ps.tracer = &pubsubTracer{
-				internal: []internalTracer{gs.score, gs.gossipTracer},
-				pid:      ps.host.ID(),
-				msgID:    ps.msgID,
+				raw:   []RawTracer{gs.score, gs.gossipTracer},
+				pid:   ps.host.ID(),
+				msgID: ps.msgID,
 			}
 		}
 

peer_gater.go

@@ -177,12 +177,12 @@ func WithPeerGater(params *PeerGaterParams) Option {
 
 		// hook the tracer
 		if ps.tracer != nil {
-			ps.tracer.internal = append(ps.tracer.internal, gs.gate)
+			ps.tracer.raw = append(ps.tracer.raw, gs.gate)
 		} else {
 			ps.tracer = &pubsubTracer{
-				internal: []internalTracer{gs.gate},
-				pid:      ps.host.ID(),
-				msgID:    ps.msgID,
+				raw:   []RawTracer{gs.gate},
+				pid:   ps.host.ID(),
+				msgID: ps.msgID,
 			}
 		}
 

pubsub.go

@@ -430,13 +430,14 @@ func WithEventTracer(tracer EventTracer) Option {
 	}
 }
 
-// withInternalTracer adds an internal event tracer to the pubsub system
-func withInternalTracer(tracer internalTracer) Option {
+// WithRawTracer adds a raw tracer to the pubsub system.
+// Multiple tracers can be added using multiple invocations of the option.
+func WithRawTracer(tracer RawTracer) Option {
 	return func(p *PubSub) error {
 		if p.tracer != nil {
-			p.tracer.internal = append(p.tracer.internal, tracer)
+			p.tracer.raw = append(p.tracer.raw, tracer)
 		} else {
-			p.tracer = &pubsubTracer{internal: []internalTracer{tracer}, pid: p.host.ID(), msgID: p.msgID}
+			p.tracer = &pubsubTracer{raw: []RawTracer{tracer}, pid: p.host.ID(), msgID: p.msgID}
 		}
 		return nil
 	}

score.go

@@ -85,7 +85,7 @@ type peerScore struct {
 	inspectPeriod time.Duration
 }
 
-var _ internalTracer = (*peerScore)(nil)
+var _ RawTracer = (*peerScore)(nil)
 
 type messageDeliveries struct {
 	records map[string]*deliveryRecord

tag_tracer.go

@@ -173,8 +173,8 @@ func (t *tagTracer) nearFirstPeers(msg *Message) []peer.ID {
 	return peers
 }
 
-// -- internalTracer interface methods
-var _ internalTracer = (*tagTracer)(nil)
+// -- RawTracer interface methods
+var _ RawTracer = (*tagTracer)(nil)
 
 func (t *tagTracer) AddPeer(p peer.ID, proto protocol.ID) {
 	t.tagPeerIfDirect(p)

trace.go

@@ -9,32 +9,53 @@ import (
 	pb "github.com/libp2p/go-libp2p-pubsub/pb"
 )
 
-// Generic event tracer interface
+// EventTracer is a generic event tracer interface.
+// This is a high level tracing interface which delivers tracing events, as defined by the protobuf
+// schema in pb/trace.proto.
 type EventTracer interface {
 	Trace(evt *pb.TraceEvent)
 }
 
-// internal interface for score tracing
-type internalTracer interface {
+// RawTracer is a low level tracing interace that allows an application to trace the internal
+// operation of the pubsub subsystem.
+//
+// Note that the tracers are invoked synchronously, which means that application tracers must
+// take care to not block or modify arguments.
+//
+// Warning: this interface is not fixed, we may be adding new methods as necessitated by the system
+// in the future.
+type RawTracer interface {
+	// AddPeer is invoked when a new peer is added.
 	AddPeer(p peer.ID, proto protocol.ID)
+	// RemovePeer is invoked when a peer is removed.
 	RemovePeer(p peer.ID)
+	// Join is invoked when a new topic is joined
 	Join(topic string)
+	// Leave is invoked when a topic is abandoned
 	Leave(topic string)
+	// Graft is invoked when a new peer is grafted on the mesh (gossipsub)
 	Graft(p peer.ID, topic string)
+	// Prune is invoked when a peer is pruned from the message (gossipsub)
 	Prune(p peer.ID, topic string)
+	// ValidateMessage is invoked when a message first enters the validation pipeline.
 	ValidateMessage(msg *Message)
+	// DeliverMessage is invoked when a message is delivered
 	DeliverMessage(msg *Message)
+	// RejectMessage is invoked when a message is Rejected or Ignored.
+	// The reason argument can be one of the named strings Reject*.
 	RejectMessage(msg *Message, reason string)
+	// DuplicateMessage is invoked when a duplicate message is dropped.
 	DuplicateMessage(msg *Message)
+	// ThrottlePeer is invoked when a peer is throttled by the peer gater.
 	ThrottlePeer(p peer.ID)
 }
 
 // pubsub tracer details
 type pubsubTracer struct {
-	tracer   EventTracer
-	internal []internalTracer
-	pid      peer.ID
-	msgID    MsgIdFunction
+	tracer EventTracer
+	raw    []RawTracer
+	pid    peer.ID
+	msgID  MsgIdFunction
 }
 
 func (t *pubsubTracer) PublishMessage(msg *Message) {
@@ -66,7 +87,7 @@ func (t *pubsubTracer) ValidateMessage(msg *Message) {
 	}
 
 	if msg.ReceivedFrom != t.pid {
-		for _, tr := range t.internal {
+		for _, tr := range t.raw {
 			tr.ValidateMessage(msg)
 		}
 	}
@@ -78,7 +99,7 @@ func (t *pubsubTracer) RejectMessage(msg *Message, reason string) {
 	}
 
 	if msg.ReceivedFrom != t.pid {
-		for _, tr := range t.internal {
+		for _, tr := range t.raw {
 			tr.RejectMessage(msg, reason)
 		}
 	}
@@ -109,7 +130,7 @@ func (t *pubsubTracer) DuplicateMessage(msg *Message) {
 	}
 
 	if msg.ReceivedFrom != t.pid {
-		for _, tr := range t.internal {
+		for _, tr := range t.raw {
 			tr.DuplicateMessage(msg)
 		}
 	}
@@ -139,7 +160,7 @@ func (t *pubsubTracer) DeliverMessage(msg *Message) {
 	}
 
 	if msg.ReceivedFrom != t.pid {
-		for _, tr := range t.internal {
+		for _, tr := range t.raw {
 			tr.DeliverMessage(msg)
 		}
 	}
@@ -168,7 +189,7 @@ func (t *pubsubTracer) AddPeer(p peer.ID, proto protocol.ID) {
 		return
 	}
 
-	for _, tr := range t.internal {
+	for _, tr := range t.raw {
 		tr.AddPeer(p, proto)
 	}
 
@@ -196,7 +217,7 @@ func (t *pubsubTracer) RemovePeer(p peer.ID) {
 		return
 	}
 
-	for _, tr := range t.internal {
+	for _, tr := range t.raw {
 		tr.RemovePeer(p)
 	}
 
@@ -366,7 +387,7 @@ func (t *pubsubTracer) Join(topic string) {
 		return
 	}
 
-	for _, tr := range t.internal {
+	for _, tr := range t.raw {
 		tr.Join(topic)
 	}
 
@@ -392,7 +413,7 @@ func (t *pubsubTracer) Leave(topic string) {
 		return
 	}
 
-	for _, tr := range t.internal {
+	for _, tr := range t.raw {
 		tr.Leave(topic)
 	}
 
@@ -418,7 +439,7 @@ func (t *pubsubTracer) Graft(p peer.ID, topic string) {
 		return
 	}
 
-	for _, tr := range t.internal {
+	for _, tr := range t.raw {
 		tr.Graft(p, topic)
 	}
 
@@ -445,7 +466,7 @@ func (t *pubsubTracer) Prune(p peer.ID, topic string) {
 		return
 	}
 
-	for _, tr := range t.internal {
+	for _, tr := range t.raw {
 		tr.Prune(p, topic)
 	}
 
@@ -472,7 +493,7 @@ func (t *pubsubTracer) ThrottlePeer(p peer.ID) {
 		return
 	}
 
-	for _, tr := range t.internal {
+	for _, tr := range t.raw {
 		tr.ThrottlePeer(p)
 	}
 }