From bfb06645818342237a44e58588469b1d99101d7a Mon Sep 17 00:00:00 2001
From: vyzo <vyzo@hackzen.org>
Date: Thu, 22 Feb 2018 10:58:58 +0200
Subject: [PATCH] retry dropped ANNOUNCE messages

they are very important for correct topic state in the protocol, esp gossipsub
---
 pubsub.go | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/pubsub.go b/pubsub.go
index 3d0b3e8..f739c3a 100644
--- a/pubsub.go
+++ b/pubsub.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"encoding/binary"
 	"fmt"
+	"math/rand"
 	"sync/atomic"
 	"time"
 
@@ -330,9 +331,18 @@ func (p *PubSub) announce(topic string, sub bool) {
 		select {
 		case peer <- out:
 		default:
-			// TODO this needs to be reliable, schedule it for piggybacking
-			//      in a subsequent message or retry later
-			log.Infof("dropping announce message to peer %s: queue full", pid)
+			log.Infof("Can't send announce message to peer %s: queue full; scheduling retry", pid)
+			go p.announceRetry(topic, sub)
+		}
+	}
+}
+
+func (p *PubSub) announceRetry(topic string, sub bool) {
+	time.Sleep(time.Duration(1+rand.Intn(1000)) * time.Millisecond)
+	p.eval <- func() {
+		_, ok := p.myTopics[topic]
+		if (ok && sub) || (!ok && !sub) {
+			p.announce(topic, sub)
 		}
 	}
 }