les: improved header fetcher and server statistics

les/odr.go

@@ -37,6 +37,11 @@ var (
 // peerDropFn is a callback type for dropping a peer detected as malicious.
 type peerDropFn func(id string)
 
+type odrPeerSelector interface {
+	selectPeer(func(*peer) (bool, uint64)) *peer
+	adjustResponseTime(*poolEntry, time.Duration, bool)
+}
+
 type LesOdr struct {
 	light.OdrBackend
 	db           ethdb.Database
@@ -44,7 +49,7 @@ type LesOdr struct {
 	removePeer   peerDropFn
 	mlock, clock sync.Mutex
 	sentReqs     map[uint64]*sentReq
-	peers        *odrPeerSet
+	serverPool   odrPeerSelector
 	lastReqID    uint64
 }
 
@@ -52,7 +57,6 @@ func NewLesOdr(db ethdb.Database) *LesOdr {
 	return &LesOdr{
 		db:       db,
 		stop:     make(chan struct{}),
-		peers:    newOdrPeerSet(),
 		sentReqs: make(map[uint64]*sentReq),
 	}
 }
@@ -77,16 +81,6 @@ type sentReq struct {
 	answered chan struct{} // closed and set to nil when any peer answers it
 }
 
-// RegisterPeer registers a new LES peer to the ODR capable peer set
-func (self *LesOdr) RegisterPeer(p *peer) error {
-	return self.peers.register(p)
-}
-
-// UnregisterPeer removes a peer from the ODR capable peer set
-func (self *LesOdr) UnregisterPeer(p *peer) {
-	self.peers.unregister(p)
-}
-
 const (
 	MsgBlockBodies = iota
 	MsgCode
@@ -142,29 +136,26 @@ func (self *LesOdr) requestPeer(req *sentReq, peer *peer, delivered, timeout cha
 
 	select {
 	case <-delivered:
-		servTime := uint64(mclock.Now() - stime)
-		self.peers.updateTimeout(peer, false)
-		self.peers.updateServTime(peer, servTime)
+		if self.serverPool != nil {
+			self.serverPool.adjustResponseTime(peer.poolEntry, time.Duration(mclock.Now()-stime), false)
+		}
 		return
 	case <-time.After(softRequestTimeout):
 		close(timeout)
-		if self.peers.updateTimeout(peer, true) {
-			self.removePeer(peer.id)
-		}
 	case <-self.stop:
 		return
 	}
 
 	select {
 	case <-delivered:
-		servTime := uint64(mclock.Now() - stime)
-		self.peers.updateServTime(peer, servTime)
-		return
 	case <-time.After(hardRequestTimeout):
-		self.removePeer(peer.id)
+		go self.removePeer(peer.id)
 	case <-self.stop:
 		return
 	}
+	if self.serverPool != nil {
+		self.serverPool.adjustResponseTime(peer.poolEntry, time.Duration(mclock.Now()-stime), true)
+	}
 }
 
 // networkRequest sends a request to known peers until an answer is received
@@ -193,7 +184,13 @@ func (self *LesOdr) networkRequest(ctx context.Context, lreq LesOdrRequest) erro
 
 	exclude := make(map[*peer]struct{})
 	for {
-		if peer := self.peers.bestPeer(lreq, exclude); peer == nil {
+		var p *peer
+		if self.serverPool != nil {
+			p = self.serverPool.selectPeer(func(p *peer) (bool, uint64) {
+				return true, p.fcServer.CanSend(lreq.GetCost(p))
+			})
+		}
+		if p == nil {
 			select {
 			case <-ctx.Done():
 				return ctx.Err()
@@ -202,17 +199,17 @@ func (self *LesOdr) networkRequest(ctx context.Context, lreq LesOdrRequest) erro
 			case <-time.After(retryPeers):
 			}
 		} else {
-			exclude[peer] = struct{}{}
+			exclude[p] = struct{}{}
 			delivered := make(chan struct{})
 			timeout := make(chan struct{})
 			req.lock.Lock()
-			req.sentTo[peer] = delivered
+			req.sentTo[p] = delivered
 			req.lock.Unlock()
 			reqWg.Add(1)
-			cost := lreq.GetCost(peer)
-			peer.fcServer.SendRequest(reqID, cost)
-			go self.requestPeer(req, peer, delivered, timeout, reqWg)
-			lreq.Request(reqID, peer)
+			cost := lreq.GetCost(p)
+			p.fcServer.SendRequest(reqID, cost)
+			go self.requestPeer(req, p, delivered, timeout, reqWg)
+			lreq.Request(reqID, p)
 
 			select {
 			case <-ctx.Done():