Address PR comments and add in more user feedback

dht.go

@@ -103,8 +103,8 @@ func (dht *IpfsDHT) Connect(ctx context.Context, npeer peer.ID) error {
 
 	// Ping new peer to register in their routing table
 	// NOTE: this should be done better...
-	if err := dht.Ping(ctx, npeer); err != nil {
-		return fmt.Errorf("failed to ping newly connected peer: %s\n", err)
+	if _, err := dht.Ping(ctx, npeer); err != nil {
+		return fmt.Errorf("failed to ping newly connected peer: %s", err)
 	}
 	log.Event(ctx, "connect", dht.self, npeer)
 	dht.Update(ctx, npeer)
@@ -329,7 +329,7 @@ func (dht *IpfsDHT) PingRoutine(t time.Duration) {
 			peers := dht.routingTable.NearestPeers(kb.ConvertKey(u.Key(id)), 5)
 			for _, p := range peers {
 				ctx, _ := context.WithTimeout(dht.Context(), time.Second*5)
-				err := dht.Ping(ctx, p)
+				_, err := dht.Ping(ctx, p)
 				if err != nil {
 					log.Errorf("Ping error: %s", err)
 				}

routing.go

@@ -3,6 +3,7 @@ package dht
 import (
 	"math"
 	"sync"
+	"time"
 
 	context "github.com/jbenet/go-ipfs/Godeps/_workspace/src/code.google.com/p/go.net/context"
 
@@ -434,12 +435,14 @@ func (dht *IpfsDHT) FindPeersConnectedToPeer(ctx context.Context, id peer.ID) (<
 }
 
 // Ping a peer, log the time it took
-func (dht *IpfsDHT) Ping(ctx context.Context, p peer.ID) error {
+func (dht *IpfsDHT) Ping(ctx context.Context, p peer.ID) (time.Duration, error) {
 	// Thoughts: maybe this should accept an ID and do a peer lookup?
 	log.Debugf("ping %s start", p)
+	before := time.Now()
 
 	pmes := pb.NewMessage(pb.Message_PING, "", 0)
 	_, err := dht.sendRequest(ctx, p, pmes)
 	log.Debugf("ping %s end (err = %s)", p, err)
-	return err
+
+	return time.Now().Sub(before), err
 }