server: exit early if not persistent peer

The point of this commit is to make future commits in the same PR easier
to review. All that this commit does is exit early if the peer we are
considering is not persistent instead of having a bunch of logic
indented in an if-clause.

server.go

@@ -3517,95 +3517,96 @@ func (s *server) peerTerminationWatcher(p *peer.Brontide, ready chan struct{}) {
 	s.removePeer(p)
 
 	// Next, check to see if this is a persistent peer or not.
-	_, ok := s.persistentPeers[pubStr]
-	if ok {
-		// We'll only need to re-launch a connection request if one
-		// isn't already currently pending.
-		if _, ok := s.persistentConnReqs[pubStr]; ok {
+	if _, ok := s.persistentPeers[pubStr]; !ok {
+		return
+	}
+
+	// We'll only need to re-launch a connection request if one
+	// isn't already currently pending.
+	if _, ok := s.persistentConnReqs[pubStr]; ok {
+		return
+	}
+
+	// We'll ensure that we locate an advertised address to use
+	// within the peer's address for reconnection purposes.
+	//
+	// TODO(roasbeef): use them all?
+	if p.Inbound() {
+		advertisedAddr, err := s.fetchNodeAdvertisedAddr(pubKey)
+		switch {
+		// We found an advertised address, so use it.
+		case err == nil:
+			p.SetAddress(advertisedAddr)
+
+		// The peer doesn't have an advertised address.
+		case err == errNoAdvertisedAddr:
+			// Fall back to the existing peer address if
+			// we're not accepting connections over Tor.
+			if s.torController == nil {
+				break
+			}
+
+			// If we are, the peer's address won't be known
+			// to us (we'll see a private address, which is
+			// the address used by our onion service to dial
+			// to lnd), so we don't have enough information
+			// to attempt a reconnect.
+			srvrLog.Debugf("Ignoring reconnection attempt "+
+				"to inbound peer %v without "+
+				"advertised address", p)
+			return
+
+		// We came across an error retrieving an advertised
+		// address, log it, and fall back to the existing peer
+		// address.
+		default:
+			srvrLog.Errorf("Unable to retrieve advertised "+
+				"address for node %x: %v", p.PubKey(),
+				err)
+		}
+	}
+
+	// Otherwise, we'll launch a new connection request in order to
+	// attempt to maintain a persistent connection with this peer.
+	connReq := &connmgr.ConnReq{
+		Addr:      p.NetAddress(),
+		Permanent: true,
+	}
+	s.persistentConnReqs[pubStr] = append(
+		s.persistentConnReqs[pubStr], connReq)
+
+	// Record the computed backoff in the backoff map.
+	backoff := s.nextPeerBackoff(pubStr, p.StartTime())
+	s.persistentPeersBackoff[pubStr] = backoff
+
+	// Initialize a retry canceller for this peer if one does not
+	// exist.
+	cancelChan, ok := s.persistentRetryCancels[pubStr]
+	if !ok {
+		cancelChan = make(chan struct{})
+		s.persistentRetryCancels[pubStr] = cancelChan
+	}
+
+	// We choose not to wait group this go routine since the Connect
+	// call can stall for arbitrarily long if we shutdown while an
+	// outbound connection attempt is being made.
+	go func() {
+		srvrLog.Debugf("Scheduling connection re-establishment to "+
+			"persistent peer %v in %s", p, backoff)
+
+		select {
+		case <-time.After(backoff):
+		case <-cancelChan:
+			return
+		case <-s.quit:
 			return
 		}
 
-		// We'll ensure that we locate an advertised address to use
-		// within the peer's address for reconnection purposes.
-		//
-		// TODO(roasbeef): use them all?
-		if p.Inbound() {
-			advertisedAddr, err := s.fetchNodeAdvertisedAddr(pubKey)
-			switch {
-			// We found an advertised address, so use it.
-			case err == nil:
-				p.SetAddress(advertisedAddr)
+		srvrLog.Debugf("Attempting to re-establish persistent "+
+			"connection to peer %v", p)
 
-			// The peer doesn't have an advertised address.
-			case err == errNoAdvertisedAddr:
-				// Fall back to the existing peer address if
-				// we're not accepting connections over Tor.
-				if s.torController == nil {
-					break
-				}
-
-				// If we are, the peer's address won't be known
-				// to us (we'll see a private address, which is
-				// the address used by our onion service to dial
-				// to lnd), so we don't have enough information
-				// to attempt a reconnect.
-				srvrLog.Debugf("Ignoring reconnection attempt "+
-					"to inbound peer %v without "+
-					"advertised address", p)
-				return
-
-			// We came across an error retrieving an advertised
-			// address, log it, and fall back to the existing peer
-			// address.
-			default:
-				srvrLog.Errorf("Unable to retrieve advertised "+
-					"address for node %x: %v", p.PubKey(),
-					err)
-			}
-		}
-
-		// Otherwise, we'll launch a new connection request in order to
-		// attempt to maintain a persistent connection with this peer.
-		connReq := &connmgr.ConnReq{
-			Addr:      p.NetAddress(),
-			Permanent: true,
-		}
-		s.persistentConnReqs[pubStr] = append(
-			s.persistentConnReqs[pubStr], connReq)
-
-		// Record the computed backoff in the backoff map.
-		backoff := s.nextPeerBackoff(pubStr, p.StartTime())
-		s.persistentPeersBackoff[pubStr] = backoff
-
-		// Initialize a retry canceller for this peer if one does not
-		// exist.
-		cancelChan, ok := s.persistentRetryCancels[pubStr]
-		if !ok {
-			cancelChan = make(chan struct{})
-			s.persistentRetryCancels[pubStr] = cancelChan
-		}
-
-		// We choose not to wait group this go routine since the Connect
-		// call can stall for arbitrarily long if we shutdown while an
-		// outbound connection attempt is being made.
-		go func() {
-			srvrLog.Debugf("Scheduling connection re-establishment to "+
-				"persistent peer %v in %s", p, backoff)
-
-			select {
-			case <-time.After(backoff):
-			case <-cancelChan:
-				return
-			case <-s.quit:
-				return
-			}
-
-			srvrLog.Debugf("Attempting to re-establish persistent "+
-				"connection to peer %v", p)
-
-			s.connMgr.Connect(connReq)
-		}()
-	}
+		s.connMgr.Connect(connReq)
+	}()
 }
 
 // removePeer removes the passed peer from the server's state of all active