p2p: instrument P2P networking layer

p2p/metrics.go

@@ -0,0 +1,49 @@
+// Contains the meters and timers used by the networking layer.
+
+package p2p
+
+import (
+	"net"
+
+	"github.com/rcrowley/go-metrics"
+)
+
+var (
+	ingressConnectMeter = metrics.GetOrRegisterMeter("p2p/InboundConnects", metrics.DefaultRegistry)
+	ingressTrafficMeter = metrics.GetOrRegisterMeter("p2p/InboundTraffic", metrics.DefaultRegistry)
+	egressConnectMeter  = metrics.GetOrRegisterMeter("p2p/OutboundConnects", metrics.DefaultRegistry)
+	egressTrafficMeter  = metrics.GetOrRegisterMeter("p2p/OutboundTraffic", metrics.DefaultRegistry)
+)
+
+// meteredConn is a wrapper around a network TCP connection that meters both the
+// inbound and outbound network traffic.
+type meteredConn struct {
+	*net.TCPConn // Network connection to wrap with metering
+}
+
+// newMeteredConn creates a new metered connection, also bumping the ingress or
+// egress connection meter.
+func newMeteredConn(conn net.Conn, ingress bool) net.Conn {
+	if ingress {
+		ingressConnectMeter.Mark(1)
+	} else {
+		egressConnectMeter.Mark(1)
+	}
+	return &meteredConn{conn.(*net.TCPConn)}
+}
+
+// Read delegates a network read to the underlying connection, bumping the ingress
+// traffic meter along the way.
+func (c *meteredConn) Read(b []byte) (n int, err error) {
+	n, err = c.TCPConn.Read(b)
+	ingressTrafficMeter.Mark(int64(n))
+	return
+}
+
+// Write delegates a network write to the underlying connection, bumping the
+// egress traffic meter along the way.
+func (c *meteredConn) Write(b []byte) (n int, err error) {
+	n, err = c.TCPConn.Write(b)
+	egressTrafficMeter.Mark(int64(n))
+	return
+}