Unit tests for gossip-based topology communication

router/gossip_test.go

@@ -0,0 +1,146 @@
+package router
+
+import (
+	wt "github.com/zettio/weave/testing"
+	"testing"
+	"time"
+)
+
+// TODO test gossip unicast and broadcast; atm we only test topology
+// gossip, which does not employ unicast or broadcast.
+
+type mockChannelConnection struct {
+	RemoteConnection
+	dest *Router
+}
+
+// Construct a "passive" Router, i.e. without any goroutines.
+//
+// We need to create some dummy channels otherwise tests hang on nil
+// channels when Router.OnGossip() calls async methods.
+func NewTestRouter(name PeerName) *Router {
+	router := NewRouter(nil, name, nil, 10, 1024, nil)
+	router.ConnectionMaker.queryChan = make(chan *ConnectionMakerInteraction, ChannelSize)
+	router.Routes.queryChan = make(chan *Interaction, ChannelSize)
+	return router
+}
+
+func (conn *mockChannelConnection) SendProtocolMsg(protocolMsg ProtocolMsg) {
+	if err := conn.dest.handleGossip(protocolMsg.msg, deliverGossip); err != nil {
+		panic(err)
+	}
+}
+
+func (router *Router) AddTestChannelConnection(r *Router) {
+	fromName := router.Ourself.Peer.Name
+	toName := r.Ourself.Peer.Name
+
+	fromPeer := NewPeer(fromName, router.Ourself.Peer.UID, 0)
+	toPeer := NewPeer(toName, r.Ourself.Peer.UID, 0)
+
+	r.Peers.FetchWithDefault(fromPeer)    // Has side-effect of incrementing refcount
+	router.Peers.FetchWithDefault(toPeer) //
+
+	conn := &mockChannelConnection{RemoteConnection{router.Ourself.Peer, toPeer, ""}, r}
+	router.Ourself.handleAddConnection(conn)
+	router.Ourself.handleConnectionEstablished(conn)
+}
+
+func (router *Router) DeleteTestChannelConnection(r *Router) {
+	fromName := router.Ourself.Peer.Name
+	toName := r.Ourself.Peer.Name
+
+	fromPeer, _ := r.Peers.Fetch(fromName)
+	toPeer, _ := router.Peers.Fetch(toName)
+
+	fromPeer.DecrementLocalRefCount()
+	toPeer.DecrementLocalRefCount()
+
+	conn, _ := router.Ourself.ConnectionTo(toName)
+	router.Ourself.handleDeleteConnection(conn)
+}
+
+func TestGossipTopology(t *testing.T) {
+	wt.RunWithTimeout(t, 1*time.Second, func() {
+		implTestGossipTopology(t)
+	})
+}
+
+// Create a Peer representing the receiver router, with connections to
+// the routers supplied as arguments, carrying across all UID and
+// version information.
+func (router *Router) tp(routers ...*Router) *Peer {
+	peer := NewPeer(router.Ourself.Peer.Name, router.Ourself.Peer.UID, 0)
+	connections := make(map[PeerName]Connection)
+	for _, r := range routers {
+		p := NewPeer(r.Ourself.Peer.Name, r.Ourself.Peer.UID, r.Ourself.Peer.version)
+		connections[r.Ourself.Peer.Name] = newMockConnection(peer, p)
+	}
+	peer.SetVersionAndConnections(router.Ourself.Peer.version, connections)
+	return peer
+}
+
+// Check that the topology of router matches the peers and all of their connections
+func checkTopology(t *testing.T, router *Router, wantedPeers ...*Peer) {
+	checkTopologyPeers(t, true, router.Peers.allPeers(), wantedPeers...)
+}
+
+func implTestGossipTopology(t *testing.T) {
+	// Create some peers that will talk to each other
+	peer1Name, _ := PeerNameFromString("01:00:00:01:00:00")
+	peer2Name, _ := PeerNameFromString("02:00:00:02:00:00")
+	peer3Name, _ := PeerNameFromString("03:00:00:03:00:00")
+	r1 := NewTestRouter(peer1Name)
+	r2 := NewTestRouter(peer2Name)
+	r3 := NewTestRouter(peer3Name)
+
+	// Check state when they have no connections
+	checkTopology(t, r1, r1.tp())
+	checkTopology(t, r2, r2.tp())
+
+	// Now try adding some connections
+	r1.AddTestChannelConnection(r2)
+	checkTopology(t, r1, r1.tp(r2), r2.tp())
+	checkTopology(t, r2, r1.tp(r2), r2.tp())
+	r2.AddTestChannelConnection(r1)
+	checkTopology(t, r1, r1.tp(r2), r2.tp(r1))
+	checkTopology(t, r2, r1.tp(r2), r2.tp(r1))
+
+	// Currently, the connection from 2 to 3 is one-way only
+	r2.AddTestChannelConnection(r3)
+	checkTopology(t, r1, r1.tp(r2), r2.tp(r1, r3), r3.tp())
+	checkTopology(t, r2, r1.tp(r2), r2.tp(r1, r3), r3.tp())
+	// When r2 gossiped to r3, 1 was unreachable from r3 so it got removed from the
+	// list of peers, but remains referenced in the connection from 1 to 3.
+	checkTopology(t, r3, r2.tp(r1, r3), r3.tp())
+
+	// Add a connection from 3 to 1 and now r1 is reachable.
+	r3.AddTestChannelConnection(r1)
+	checkTopology(t, r1, r1.tp(r2), r2.tp(r1, r3), r3.tp(r1))
+	checkTopology(t, r2, r1.tp(r2), r2.tp(r1, r3), r3.tp(r1))
+	checkTopology(t, r3, r1.tp(), r2.tp(r1, r3), r3.tp(r1))
+
+	r1.AddTestChannelConnection(r3)
+	checkTopology(t, r1, r1.tp(r2, r3), r2.tp(r1, r3), r3.tp(r1))
+	checkTopology(t, r2, r1.tp(r2, r3), r2.tp(r1, r3), r3.tp(r1))
+	checkTopology(t, r3, r1.tp(r2, r3), r2.tp(r1, r3), r3.tp(r1))
+
+	// Drop the connection from 2 to 3
+	r2.DeleteTestChannelConnection(r3)
+	checkTopology(t, r1, r1.tp(r2, r3), r2.tp(r1), r3.tp(r1))
+	checkTopology(t, r2, r1.tp(r2, r3), r2.tp(r1))
+	checkTopology(t, r3, r1.tp(r2, r3), r2.tp(r1), r3.tp(r1))
+
+	// Drop the connection from 1 to 3
+	r1.DeleteTestChannelConnection(r3)
+	checkTopology(t, r1, r1.tp(r2), r2.tp(r1), r3.tp(r1))
+
+	checkTopology(t, r1, r1.tp(r2), r2.tp(r1), r3.tp(r1))
+	checkTopology(t, r2, r1.tp(r2), r2.tp(r1))
+	// r3 still thinks r1 has a connection to it
+	checkTopology(t, r3, r1.tp(r2, r3), r2.tp(r1), r3.tp(r1))
+
+	// On a timer, r3 will gossip to r1
+	r3.SendAllGossip()
+	checkTopology(t, r1, r1.tp(r2), r2.tp(r1), r3.tp(r1))
+}