permit encoding of GossipData into multiple messages

ipam/allocator.go

@@ -435,8 +435,8 @@ func (d *ipamGossipData) Merge(other router.GossipData) {
 	// no-op
 }
 
-func (d *ipamGossipData) Encode() []byte {
-	return d.alloc.Encode()
+func (d *ipamGossipData) Encode() [][]byte {
+	return [][]byte{d.alloc.Encode()}
 }
 
 // Gossip returns a GossipData implementation, which in this case always

ipam/testutils_test.go

@@ -258,8 +258,10 @@ func (grouter *TestGossipRouter) connect(sender router.PeerName, gossiper router
 						panic(fmt.Sprintf("Error doing gossip unicast to %s: %s", sender, err))
 					}
 				} else {
-					if _, err := gossiper.OnGossipBroadcast(message.data.Encode()); err != nil {
-						panic(fmt.Sprintf("Error doing gossip broadcast to %s: %s", sender, err))
+					for _, msg := range message.data.Encode() {
+						if _, err := gossiper.OnGossipBroadcast(msg); err != nil {
+							panic(fmt.Sprintf("Error doing gossip broadcast to %s: %s", sender, err))
+						}
 					}
 				}
 			case <-gossipTimer:

router/gossip.go

@@ -5,7 +5,7 @@ import (
 )
 
 type GossipData interface {
-	Encode() []byte
+	Encode() [][]byte
 	Merge(GossipData)
 }
 

router/gossip_channel.go

@@ -145,8 +145,10 @@ func (c *GossipChannel) sendDown(conn Connection, data GossipData) {
 	sender, found := c.senders[conn]
 	if !found {
 		sender = NewGossipSender(func(pending GossipData) {
-			protocolMsg := ProtocolMsg{ProtocolGossip, GobEncode(c.name, c.ourself.Name, pending.Encode())}
-			conn.(ProtocolSender).SendProtocolMsg(protocolMsg)
+			for _, msg := range pending.Encode() {
+				protocolMsg := ProtocolMsg{ProtocolGossip, GobEncode(c.name, c.ourself.Name, msg)}
+				conn.(ProtocolSender).SendProtocolMsg(protocolMsg)
+			}
 		})
 		c.senders[conn] = sender
 		sender.Start()
@@ -212,10 +214,13 @@ func (c *GossipChannel) sendBroadcast(srcName PeerName, update GossipData) {
 	if len(nextHops) == 0 {
 		return
 	}
-	protocolMsg := ProtocolMsg{ProtocolGossipBroadcast, GobEncode(c.name, srcName, update.Encode())}
-	// FIXME a single blocked connection can stall us
-	for _, conn := range c.ourself.ConnectionsTo(nextHops) {
-		conn.(ProtocolSender).SendProtocolMsg(protocolMsg)
+	connections := c.ourself.ConnectionsTo(nextHops)
+	for _, msg := range update.Encode() {
+		protocolMsg := ProtocolMsg{ProtocolGossipBroadcast, GobEncode(c.name, srcName, msg)}
+		// FIXME a single blocked connection can stall us
+		for _, conn := range connections {
+			conn.(ProtocolSender).SendProtocolMsg(protocolMsg)
+		}
 	}
 }
 

router/router.go

@@ -394,8 +394,8 @@ func (d *TopologyGossipData) Merge(other GossipData) {
 	}
 }
 
-func (d *TopologyGossipData) Encode() []byte {
-	return d.peers.EncodePeers(d.update)
+func (d *TopologyGossipData) Encode() [][]byte {
+	return [][]byte{d.peers.EncodePeers(d.update)}
 }
 
 func (router *Router) OnGossipUnicast(sender PeerName, msg []byte) error {