bitswap: add peer-prom-tracker

For #209
Need examples.

bitswap/peer-prom-tracker/peer-prom-tracker.go

@@ -0,0 +1,146 @@
+package peerpromtracker
+
+import (
+	"errors"
+	"fmt"
+
+	bsmsg "github.com/ipfs/boxo/bitswap/message"
+	"github.com/ipfs/boxo/bitswap/tracer"
+	"github.com/ipfs/go-log/v2"
+	peer "github.com/libp2p/go-libp2p/core/peer"
+	prom "github.com/prometheus/client_golang/prometheus"
+)
+
+var logger = log.Logger("bitswap/peer-prom-tracker")
+
+var _ tracer.Tracer = (*PeerTracer)(nil)
+
+type PeerTracer struct {
+	bytesSent        *prom.CounterVec
+	messagesSent     *prom.CounterVec
+	bytesReceived    *prom.CounterVec
+	messagesReceived *prom.CounterVec
+
+	reg *prom.Registry
+}
+
+func NewPeerTracer(reg *prom.Registry) (*PeerTracer, error) {
+	pt := &PeerTracer{
+		reg: reg,
+	}
+
+	var good bool
+	defer func() {
+		if !good {
+			pt.Close() // will unregister the sucessfully registered metrics
+		}
+	}()
+
+	peerIdLabel := []string{"peer-id"}
+
+	bytesSent := prom.NewCounterVec(prom.CounterOpts{
+		Namespace: "ipfs",
+		Subsystem: "bitswap/messages",
+		Name:      "bytes-sent",
+		Help:      "This records the number of bitswap messages bytes sent per peer.",
+	}, peerIdLabel)
+	if err := reg.Register(bytesSent); err != nil {
+		return nil, fmt.Errorf("registering bytes-sent: %w", err)
+	}
+	pt.bytesSent = bytesSent
+
+	messagesSent := prom.NewCounterVec(prom.CounterOpts{
+		Namespace: "ipfs",
+		Subsystem: "bitswap/messages",
+		Name:      "messages-sent",
+		Help:      "This records the number of bitswap messages sent per peer.",
+	}, peerIdLabel)
+	if err := reg.Register(messagesSent); err != nil {
+		return nil, fmt.Errorf("registering messages-sent: %w", err)
+	}
+	pt.messagesSent = messagesSent
+
+	bytesReceived := prom.NewCounterVec(prom.CounterOpts{
+		Namespace: "ipfs",
+		Subsystem: "bitswap/messages",
+		Name:      "bytes-received",
+		Help:      "This records the number of bitswap messages bytes received from each peer.",
+	}, peerIdLabel)
+	if err := reg.Register(bytesReceived); err != nil {
+		return nil, fmt.Errorf("registering bytes-received: %w", err)
+	}
+	pt.bytesReceived = bytesReceived
+
+	messagesReceived := prom.NewCounterVec(prom.CounterOpts{
+		Namespace: "ipfs",
+		Subsystem: "bitswap/messages",
+		Name:      "messages-received",
+		Help:      "This records the number of bitswap messages received from each peer.",
+	}, peerIdLabel)
+	if err := reg.Register(messagesReceived); err != nil {
+		return nil, fmt.Errorf("registering messages-received: %w", err)
+	}
+	pt.messagesReceived = messagesReceived
+
+	good = true
+	return pt, nil
+}
+
+func (t *PeerTracer) MessageReceived(p peer.ID, msg bsmsg.BitSwapMessage) {
+	strPeerid := p.Pretty()
+
+	counter, err := t.messagesReceived.GetMetricWithLabelValues(strPeerid)
+	if err == nil {
+		logger.Debugf("failed to grab messages received label %s", err)
+	} else {
+		counter.Inc()
+	}
+
+	counter, err = t.bytesReceived.GetMetricWithLabelValues(strPeerid)
+	if err == nil {
+		logger.Debugf("failed to grab messages received label %s", err)
+	} else {
+		counter.Add(float64(msg.Size()))
+	}
+}
+
+func (t *PeerTracer) MessageSent(p peer.ID, msg bsmsg.BitSwapMessage) {
+	strPeerid := p.Pretty()
+
+	counter, err := t.messagesSent.GetMetricWithLabelValues(strPeerid)
+	if err == nil {
+		logger.Debugf("failed to grab messages received label %s", err)
+	} else {
+		counter.Inc()
+	}
+
+	counter, err = t.bytesSent.GetMetricWithLabelValues(strPeerid)
+	if err == nil {
+		logger.Debugf("failed to grab messages received label %s", err)
+	} else {
+		counter.Add(float64(msg.Size()))
+	}
+}
+
+func (t *PeerTracer) Close() error {
+	if t.reg == nil {
+		return errors.New("already closed")
+	}
+
+	// we have to check because this can be called by [NewPeerTracer] if an errors occurs.
+	if t.bytesSent != nil {
+		t.reg.Unregister(t.bytesSent)
+	}
+	if t.messagesSent != nil {
+		t.reg.Unregister(t.messagesSent)
+	}
+	if t.bytesReceived != nil {
+		t.reg.Unregister(t.bytesReceived)
+	}
+	if t.messagesReceived != nil {
+		t.reg.Unregister(t.messagesReceived)
+	}
+	*t = PeerTracer{}
+
+	return nil
+}