p2p/discover: code review fixes

p2p/discover/node.go

@@ -18,6 +18,8 @@ import (
 	"github.com/ethereum/go-ethereum/rlp"
 )
 
+const nodeIDBits = 512
+
 // Node represents a host on the network.
 type Node struct {
 	ID NodeID
@@ -135,7 +137,7 @@ func (n *Node) DecodeRLP(s *rlp.Stream) (err error) {
 
 // NodeID is a unique identifier for each node.
 // The node identifier is a marshaled elliptic curve public key.
-type NodeID [512 / 8]byte
+type NodeID [nodeIDBits / 8]byte
 
 // NodeID prints as a long hexadecimal number.
 func (n NodeID) String() string {

p2p/discover/table.go

@@ -14,9 +14,9 @@ import (
 )
 
 const (
-	alpha      = 3                   // Kademlia concurrency factor
-	bucketSize = 16                  // Kademlia bucket size
-	nBuckets   = len(NodeID{})*8 + 1 // Number of buckets
+	alpha      = 3              // Kademlia concurrency factor
+	bucketSize = 16             // Kademlia bucket size
+	nBuckets   = nodeIDBits + 1 // Number of buckets
 )
 
 type Table struct {
@@ -100,7 +100,7 @@ func (tab *Table) Lookup(target NodeID) []*Node {
 	tab.mutex.Unlock()
 
 	for {
-		// ask the closest nodes that we haven't asked yet
+		// ask the alpha closest nodes that we haven't asked yet
 		for i := 0; i < len(result.entries) && pendingQueries < alpha; i++ {
 			n := result.entries[i]
 			if !asked[n.ID] {

p2p/discover/udp.go

@@ -28,7 +28,7 @@ var (
 const (
 	respTimeout = 300 * time.Millisecond
 	sendTimeout = 300 * time.Millisecond
-	expiration  = 3 * time.Second
+	expiration  = 20 * time.Second
 
 	refreshInterval = 1 * time.Hour
 )
@@ -185,7 +185,7 @@ func (t *udp) findnode(to *Node, target NodeID) ([]*Node, error) {
 				nodes = append(nodes, n)
 			}
 		}
-		return nreceived == bucketSize
+		return nreceived >= bucketSize
 	})
 
 	t.send(to, findnodePacket, findnode{