From e5f9c5e60fca68424ee3f3e9533c745c5c9aeb81 Mon Sep 17 00:00:00 2001
From: rjl493456442 <garyrong0905@gmail.com>
Date: Sun, 29 Jul 2018 19:57:45 +0800
Subject: [PATCH] les: don't bother cmManager if client request cost exceeds
 the limit

---
 les/flowcontrol/control.go | 10 ++++++++--
 les/flowcontrol/manager.go |  5 ++---
 les/handler.go             |  4 ++--
 3 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/les/flowcontrol/control.go b/les/flowcontrol/control.go
index d50eb809cc..bcea5c3945 100644
--- a/les/flowcontrol/control.go
+++ b/les/flowcontrol/control.go
@@ -66,13 +66,19 @@ func (peer *ClientNode) recalcBV(time mclock.AbsTime) {
 	peer.lastTime = time
 }
 
-func (peer *ClientNode) AcceptRequest() (uint64, bool) {
+func (peer *ClientNode) AcceptRequest(maxCost uint64) (uint64, bool) {
 	peer.lock.Lock()
 	defer peer.lock.Unlock()
 
 	time := mclock.Now()
 	peer.recalcBV(time)
-	return peer.bufValue, peer.cm.accept(peer.cmNode, time)
+	// Reject request directly if the client doesn't comply with the rate limit rules.
+	if peer.bufValue < maxCost {
+		return peer.bufValue, false
+	}
+	peer.cm.accept(peer.cmNode, time)
+	peer.recalcBV(time)
+	return peer.bufValue, true
 }
 
 func (peer *ClientNode) RequestProcessed(cost uint64) (bv, realCost uint64) {
diff --git a/les/flowcontrol/manager.go b/les/flowcontrol/manager.go
index 28cc6f0fe7..6a08786b20 100644
--- a/les/flowcontrol/manager.go
+++ b/les/flowcontrol/manager.go
@@ -184,7 +184,7 @@ func (self *ClientManager) queueProc() {
 	}
 }
 
-func (self *ClientManager) accept(node *cmNode, time mclock.AbsTime) bool {
+func (self *ClientManager) accept(node *cmNode, time mclock.AbsTime) {
 	self.lock.Lock()
 	defer self.lock.Unlock()
 
@@ -196,14 +196,13 @@ func (self *ClientManager) accept(node *cmNode, time mclock.AbsTime) bool {
 		<-resume
 		self.lock.Lock()
 		if _, ok := self.nodes[node]; !ok {
-			return false // reject if node has been removed or manager has been stopped
+			panic("the node should never be removed during the request waiting")
 		}
 	}
 	self.simReqCnt++
 	node.set(true, self.simReqCnt, self.sumWeight)
 	node.startValue = node.rcValue
 	self.update(self.time)
-	return true
 }
 
 func (self *ClientManager) stop(node *cmNode, time mclock.AbsTime) {
diff --git a/les/handler.go b/les/handler.go
index a1c16cb875..769b039b6c 100644
--- a/les/handler.go
+++ b/les/handler.go
@@ -350,12 +350,12 @@ func (pm *ProtocolManager) handleMsg(p *peer) error {
 		if p.fcClient == nil || reqCnt > maxCnt {
 			return true
 		}
-		bufValue, _ := p.fcClient.AcceptRequest()
 		cost := costs.baseCost + reqCnt*costs.reqCost
 		if cost > pm.server.defParams.BufLimit {
 			cost = pm.server.defParams.BufLimit
 		}
-		if cost > bufValue {
+		bufValue, serve := p.fcClient.AcceptRequest(cost)
+		if !serve {
 			recharge := time.Duration((cost - bufValue) * 1000000 / pm.server.defParams.MinRecharge)
 			p.Log().Error("Request came too early", "recharge", common.PrettyDuration(recharge))
 			return true