netsync: add logger for blocks downloaded from different peers during

headers-first block download

netsync/blocklogger.go

@@ -82,3 +82,61 @@ func (b *blockProgressLogger) LogBlockHeight(block *btcutil.Block, chain *blockc
 func (b *blockProgressLogger) SetLastLogTime(time time.Time) {
 	b.lastBlockLogTime = time
 }
+
+// peerLogger logs the progress of blocks downloaded from different peers during
+// headers-first download.
+type peerLogger struct {
+	lastPeerLogTime time.Time
+	peers           map[string]int
+
+	subsystemLogger btclog.Logger
+	sync.Mutex
+}
+
+// newPeerLogger returns a new peerLogger with fields initialized.
+func newPeerLogger(logger btclog.Logger) *peerLogger {
+	return &peerLogger{
+		lastPeerLogTime: time.Now(),
+		subsystemLogger: logger,
+		peers:           make(map[string]int),
+	}
+}
+
+// LogPeers logs how many blocks have been received from which peers in the last
+// 10 seconds.
+func (p *peerLogger) LogPeers(peer string) {
+	p.Lock()
+	defer p.Unlock()
+
+	count, found := p.peers[peer]
+	if found {
+		count++
+		p.peers[peer] = count
+	} else {
+		p.peers[peer] = 1
+	}
+
+	now := time.Now()
+	duration := now.Sub(p.lastPeerLogTime)
+	if duration < time.Second*10 {
+		return
+	}
+	// Truncate the duration to 10s of milliseconds.
+	durationMillis := int64(duration / time.Millisecond)
+	tDuration := 10 * time.Millisecond * time.Duration(durationMillis/10)
+
+	peerDownloadStr := ""
+	for peer, blockCount := range p.peers {
+		peerDownloadStr += fmt.Sprintf("%d blocks from %v, ",
+			blockCount, peer)
+	}
+
+	p.subsystemLogger.Infof("Peer download stats in the last %s: %s",
+		tDuration, peerDownloadStr)
+
+	// Reset fields.
+	p.lastPeerLogTime = now
+	for k := range p.peers {
+		delete(p.peers, k)
+	}
+}

netsync/manager.go

@@ -236,6 +236,7 @@ type SyncManager struct {
 	txMemPool      *mempool.TxPool
 	chainParams    *chaincfg.Params
 	progressLogger *blockProgressLogger
+	peerLogger     *peerLogger
 	msgChan        chan interface{}
 	wg             sync.WaitGroup
 	quit           chan struct{}
@@ -932,6 +933,10 @@ func (sm *SyncManager) handleBlockMsg(bmsg *blockMsg) {
 		}
 	}
 
+	if sm.headersFirstMode {
+		go sm.peerLogger.LogPeers(peer.Addr())
+	}
+
 	// Since we may receive blocks out of order, attempt to find the next block
 	// and any other descendent blocks that connect to it.
 	processBlocks := make([]*blockMsg, 0, 1)
@@ -1917,6 +1922,7 @@ func New(config *Config) (*SyncManager, error) {
 		requestedBlocks: make(map[chainhash.Hash]struct{}),
 		peerStates:      make(map[*peerpkg.Peer]*peerSyncState),
 		progressLogger:  newBlockProgressLogger("Processed", log),
+		peerLogger:      newPeerLogger(log),
 		msgChan:         make(chan interface{}, config.MaxPeers*3),
 		headerList:      list.New(),
 		quit:            make(chan struct{}),