added benchmark, it's not pretty

libdisco/disco_test.go

@@ -0,0 +1,193 @@
+package libdisco
+
+import (
+	"fmt"
+	"io"
+	"math"
+	"net"
+	"testing"
+	"time"
+)
+
+/*
+ * These benchmarks were stolen from crypto/tls
+ *
+ */
+
+func newLocalListener(t testing.TB) net.Listener {
+	ln, err := net.Listen("tcp", "127.0.0.1:0")
+	if err != nil {
+		ln, err = net.Listen("tcp6", "[::1]:0")
+	}
+	if err != nil {
+		t.Fatal(err)
+	}
+	return ln
+}
+
+func throughput(b *testing.B, totalBytes int64) {
+
+	serverKeyPair := GenerateKeypair(nil)
+
+	ln := newLocalListener(b)
+	defer ln.Close()
+
+	N := b.N
+
+	// Less than 64KB because Windows appears to use a TCP rwin < 64KB.
+	// See Issue #15899.
+	const bufsize = 32 << 10
+
+	go func() {
+		buf := make([]byte, bufsize)
+		for i := 0; i < N; i++ {
+			sconn, err := ln.Accept()
+			if err != nil {
+				// panic rather than synchronize to avoid benchmark overhead
+				// (cannot call b.Fatal in goroutine)
+				panic(fmt.Errorf("accept: %v", err))
+			}
+			serverConfig := &Config{
+				HandshakePattern: Noise_NK,
+				KeyPair:          serverKeyPair,
+			}
+			srv := Server(sconn, serverConfig)
+			if err := srv.Handshake(); err != nil {
+				panic(fmt.Errorf("handshake: %v", err))
+			}
+			if _, err := io.CopyBuffer(srv, srv, buf); err != nil {
+				panic(fmt.Errorf("copy buffer: %v", err))
+			}
+		}
+	}()
+
+	b.SetBytes(totalBytes)
+	clientConfig := &Config{
+		HandshakePattern: Noise_NK,
+		RemoteKey:        serverKeyPair.PublicKey[:],
+	}
+
+	buf := make([]byte, bufsize)
+	chunks := int(math.Ceil(float64(totalBytes) / float64(len(buf))))
+	for i := 0; i < N; i++ {
+		conn, err := Dial("tcp", ln.Addr().String(), clientConfig)
+		if err != nil {
+			b.Fatal(err)
+		}
+		for j := 0; j < chunks; j++ {
+			_, err := conn.Write(buf)
+			if err != nil {
+				b.Fatal(err)
+			}
+			_, err = io.ReadFull(conn, buf)
+			if err != nil {
+				b.Fatal(err)
+			}
+		}
+		conn.Close()
+	}
+}
+
+func BenchmarkThroughput(b *testing.B) {
+	for size := 1; size <= 64; size <<= 1 {
+		name := fmt.Sprintf("Packet/%dMB", size)
+		b.Run(name, func(b *testing.B) {
+			throughput(b, int64(size<<20))
+		})
+	}
+}
+
+type slowConn struct {
+	net.Conn
+	bps int
+}
+
+func (c *slowConn) Write(p []byte) (int, error) {
+	if c.bps == 0 {
+		panic("too slow")
+	}
+	t0 := time.Now()
+	wrote := 0
+	for wrote < len(p) {
+		time.Sleep(100 * time.Microsecond)
+		allowed := int(time.Since(t0).Seconds()*float64(c.bps)) / 8
+		if allowed > len(p) {
+			allowed = len(p)
+		}
+		if wrote < allowed {
+			n, err := c.Conn.Write(p[wrote:allowed])
+			wrote += n
+			if err != nil {
+				return wrote, err
+			}
+		}
+	}
+	return len(p), nil
+}
+
+func latency(b *testing.B, bps int) {
+	ln := newLocalListener(b)
+	defer ln.Close()
+
+	N := b.N
+
+	serverKeyPair := GenerateKeypair(nil)
+
+	go func() {
+		for i := 0; i < N; i++ {
+			sconn, err := ln.Accept()
+			if err != nil {
+				// panic rather than synchronize to avoid benchmark overhead
+				// (cannot call b.Fatal in goroutine)
+				panic(fmt.Errorf("accept: %v", err))
+			}
+			serverConfig := &Config{
+				HandshakePattern: Noise_NK,
+				KeyPair:          serverKeyPair,
+			}
+			srv := Server(&slowConn{sconn, bps}, serverConfig)
+			if err := srv.Handshake(); err != nil {
+				panic(fmt.Errorf("handshake: %v", err))
+			}
+			io.Copy(srv, srv)
+		}
+	}()
+
+	clientConfig := &Config{
+		HandshakePattern: Noise_NK,
+		RemoteKey:        serverKeyPair.PublicKey[:],
+	}
+
+	buf := make([]byte, 16384)
+	peek := make([]byte, 1)
+
+	for i := 0; i < N; i++ {
+		conn, err := Dial("tcp", ln.Addr().String(), clientConfig)
+		if err != nil {
+			b.Fatal(err)
+		}
+		// make sure we're connected and previous connection has stopped
+		if _, err := conn.Write(buf[:1]); err != nil {
+			b.Fatal(err)
+		}
+		if _, err := io.ReadFull(conn, peek); err != nil {
+			b.Fatal(err)
+		}
+		if _, err := conn.Write(buf); err != nil {
+			b.Fatal(err)
+		}
+		if _, err = io.ReadFull(conn, peek); err != nil {
+			b.Fatal(err)
+		}
+		conn.Close()
+	}
+}
+
+func BenchmarkLatency(b *testing.B) {
+	for _, kbps := range []int{200, 500, 1000, 2000, 5000} {
+		name := fmt.Sprintf("%dkbps", kbps)
+		b.Run(name, func(b *testing.B) {
+			latency(b, kbps*1000)
+		})
+	}
+}