[FAB-2007] Gossip/discovery: Change Exists to Lookup

In order to support FAB-2007, the gossip layer needs to figure out
whether a remote peer has published an external endpoint or not,
to know if to send (or not) Alive messages of external organizations

Change-Id: I2e0055e163fa413295caa736098d2657f2bef65f
Signed-off-by: Yacov Manevich <[email protected]>

Author: yacovm

gossip/discovery/discovery.go

@@ -93,9 +93,8 @@ func (nm NetworkMember) PreferredEndpoint() string {
 // Discovery is the interface that represents a discovery module
 type Discovery interface {
 
-	// Exists returns whether a peer with given
-	// PKI-ID is known
-	Exists(PKIID common.PKIidType) bool
+	// Lookup returns a network member, or nil if not found
+	Lookup(PKIID common.PKIidType) *NetworkMember
 
 	// Self returns this instance's membership information
 	Self() NetworkMember

gossip/discovery/discovery_impl.go

@@ -124,13 +124,12 @@ func NewDiscoveryService(bootstrapPeers []string, self NetworkMember, comm CommS
 	return d
 }
 
-// Exists returns whether a peer with given
-// PKI-ID is known
-func (d *gossipDiscoveryImpl) Exists(PKIID common.PKIidType) bool {
+// Lookup returns a network member, or nil if not found
+func (d *gossipDiscoveryImpl) Lookup(PKIID common.PKIidType) *NetworkMember {
 	d.lock.RLock()
 	defer d.lock.RUnlock()
-	_, exists := d.id2Member[string(PKIID)]
-	return exists
+	nm := d.id2Member[string(PKIID)]
+	return nm
 }
 
 func (d *gossipDiscoveryImpl) Connect(member NetworkMember, sendInternalEndpoint bool) {
@@ -291,8 +290,7 @@ func (d *gossipDiscoveryImpl) handleMsgFromComm(m *proto.SignedGossipMessage) {
 		return
 	}
 	if m.GetAliveMsg() == nil && m.GetMemRes() == nil && m.GetMemReq() == nil {
-		d.logger.Warning("Got message with wrong type (expected Alive or MembershipResponse or MembershipRequest message):", m.Content) // TODO: write only message type
-		d.logger.Warning(m)
+		d.logger.Warning("Got message with wrong type (expected Alive or MembershipResponse or MembershipRequest message):", m.GossipMessage)
 		return
 	}
 

gossip/discovery/discovery_test.go

@@ -526,10 +526,11 @@ func TestGetFullMembership(t *testing.T) {
 		}
 	}
 
-	// Check that Exists() is valid
+	// Check that Lookup() is valid
 	for _, inst := range instances {
 		for _, member := range inst.GetMembership() {
-			assert.True(t, inst.Exists(member.PKIid))
+			assert.Equal(t, string(member.PKIid), inst.Lookup(member.PKIid).Endpoint)
+			assert.Equal(t, member.PKIid, inst.Lookup(member.PKIid).PKIid)
 		}
 	}