From 0f968ba7a233919798b3b3e85b7bbf0cf84d78ac Mon Sep 17 00:00:00 2001
From: Louis Thibault <l.thibault@sentimens.com>
Date: Tue, 8 Aug 2023 12:27:56 -0400
Subject: [PATCH] Log incoming subscription messages.

---
 stream/stream.go              |  8 ++++++--
 stream/transport/transport.go | 25 +++++++++++++++++++++++++
 2 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/stream/stream.go b/stream/stream.go
index 793c48bb..f87f3c5c 100644
--- a/stream/stream.go
+++ b/stream/stream.go
@@ -136,6 +136,8 @@ func subscribe(ctx context.Context, log log.Logger, ps PubSub, handle func(conte
 	s := ps.Subscribe(ctx)
 	defer s.Close()
 
+	log = log.WithField("topic", ps.String())
+
 	for {
 		msg, err := s.Next(ctx)
 		if err != nil {
@@ -147,10 +149,12 @@ func subscribe(ctx context.Context, log log.Logger, ps PubSub, handle func(conte
 				return
 			}
 
-			log.WithError(err).
-				WithField("topic", ps.String()).
+			log.With(msg).
+				WithError(err).
 				Warn("failed to handle subscription event")
 		}
+
+		log.With(msg).Debug("handled subscription event")
 	}
 }
 
diff --git a/stream/transport/transport.go b/stream/transport/transport.go
index 876976d9..dbdd8e72 100644
--- a/stream/transport/transport.go
+++ b/stream/transport/transport.go
@@ -29,12 +29,37 @@ type Subscription interface {
 
 type ForkVersionFormat uint64
 
+func (f ForkVersionFormat) String() string {
+	switch f {
+	case Unknown:
+		return "none"
+	case AltairJson:
+		return "altair/json"
+	case BellatrixJson:
+		return "bellatrix/json"
+	case CapellaJson:
+		return "capella/json"
+	case CapellaSSZ:
+		return "capella/ssz"
+	}
+
+	return fmt.Sprintf("invalid: %d", f)
+}
+
 type Message struct {
 	Source       uuid.UUID
 	ForkEncoding ForkVersionFormat
 	Payload      []byte
 }
 
+func (m Message) Loggable() map[string]any {
+	return map[string]any{
+		"source":        m.Source,
+		"fork_encoding": m.ForkEncoding,
+		"n_bytes":       len(m.Payload),
+	}
+}
+
 func Encode(m Message) ([]byte, error) {
 	rawItem, err := json.Marshal(m)
 	if err != nil {