eth/protocols/handler: add packet sending condition, prevent send sma…

…ll packets frequently;

eth/protocols/eth/broadcast.go

@@ -18,6 +18,7 @@ package eth
 
 import (
 	"math/big"
+	"time"
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/gopool"
@@ -27,7 +28,9 @@ import (
 const (
 	// This is the target size for the packs of transactions or announcements. A
 	// pack can get larger than this if a single transactions exceeds this size.
-	maxTxPacketSize = 100 * 1024
+	maxTxPacketSize   = 100 * 1024
+	minTxPacketSize   = 1 * 1024
+	sendPacketTimeout = 300 * time.Millisecond
 )
 
 // blockPropagation is a block propagation event, waiting for its turn in the
@@ -136,14 +139,15 @@ func (p *Peer) broadcastTransactions() {
 // node internals and at the same time rate limits queued data.
 func (p *Peer) announceTransactions() {
 	var (
-		queue  []common.Hash         // Queue of hashes to announce as transaction stubs
-		done   chan struct{}         // Non-nil if background announcer is running
-		fail   = make(chan error, 1) // Channel used to receive network error
-		failed bool                  // Flag whether a send failed, discard everything onward
+		queue        []common.Hash         // Queue of hashes to announce as transaction stubs
+		done         chan struct{}         // Non-nil if background announcer is running
+		fail         = make(chan error, 1) // Channel used to receive network error
+		failed       bool                  // Flag whether a send failed, discard everything onward
+		lastSentTime = time.Now()
 	)
 	for {
 		// If there's no in-flight announce running, check if a new one is needed
-		if done == nil && len(queue) > 0 {
+		if done == nil && triggerPacketSending(len(queue)*common.HashLength, lastSentTime) {
 			// Pile transaction hashes until we reach our allowed network limit
 			var (
 				count   int
@@ -170,6 +174,7 @@ func (p *Peer) announceTransactions() {
 					close(done)
 					//p.Log().Trace("Sent transaction announcements", "count", len(pending))
 				})
+				lastSentTime = time.Now()
 			}
 		}
 		// Transfer goroutine may or may not have been started, listen for events
@@ -200,3 +205,16 @@ func (p *Peer) announceTransactions() {
 		}
 	}
 }
+
+// triggerPacketSending if packet reach minTxPacketSize or sendPacketTimeout, it will trigger packet sending
+// to prevent only small packets sent frequently in network
+func triggerPacketSending(estimateSize int, lastSentTime time.Time) bool {
+	if estimateSize >= minTxPacketSize {
+		return true
+	}
+
+	if time.Since(lastSentTime) >= sendPacketTimeout && estimateSize > 0 {
+		return true
+	}
+	return false
+}