tcpdelay.go

@@ -2,8 +2,8 @@ package main
 
 import (
 	"encoding/binary"
-	"fmt"
 	"gopkg.in/alecthomas/kingpin.v2"
+	"fmt"
 	"log"
 	"net"
 	"os"
@@ -18,7 +18,6 @@ var (
 
 	client = app.Command("client", "Request measurement")
 	serverAddress = client.Arg("address", "Address:port to connect to").String()
-	relativeTimes = client.Flag("relative", "Print times relative to start").Bool()
 )
 
 func tcpdelayServer() {
@@ -57,7 +56,6 @@ func tcpdelayServer() {
 }
 
 func tcpdelayClient() {
-	t0 := time.Now().UnixNano()
 	conn, err := net.Dial("tcp", *serverAddress)
 	if err != nil {
 		log.Fatal("Cannot connect to ", *serverAddress, err)
@@ -65,17 +63,13 @@ func tcpdelayClient() {
 	o := 0
 	buffer := make([]byte, 1024)
 	for {
-		n := 0
-		for n < len(buffer) {
-			nr, err := conn.Read(buffer[n:])
+		n, err := conn.Read(buffer)
 		if err != nil {
-				log.Fatal("Cannot read from ", *serverAddress, err.Error())
+			log.Fatal("Cannot read from ", *serverAddress, err)
 		}
-			if nr <= 0 {
+		if n != len(buffer) {
 			log.Fatal("Read ", n, " bytes intead of ", len(buffer))
 		}
-			n += nr
-		}
 		tr := time.Now().UnixNano()
 		if string(buffer[0:8]) != "tcpdelay" {
 			log.Fatal("Unexpected magic ", buffer[0:8])
@@ -85,11 +79,7 @@ func tcpdelayClient() {
 			log.Fatal("Unexpected offset ", oSent, " instead of ", o)
 		}
 		ts := binary.BigEndian.Uint64(buffer[16:])
-		if *relativeTimes {
-			fmt.Println(o, int64(ts)-t0, tr-t0)
-		} else {
-			fmt.Println(o, ts, tr)
-		}
+		fmt.Println(o, ts, tr) // XXX - buffer for performance
 		o += n
 	}