xP: use buffered reads

xP/xP.go

@@ -4,6 +4,7 @@
 package main
 
 import (
+	"bufio"
 	"context"
 	"encoding/binary"
 	"encoding/json"
@@ -27,14 +28,14 @@ var (
 
 // -----------------------------------------------------------------------------
 
-func relayReadJSON(conn net.Conn) []byte {
+func relayReadJSON(r io.Reader) []byte {
 	var length uint32
-	if err := binary.Read(conn, binary.BigEndian, &length); err != nil {
+	if err := binary.Read(r, binary.BigEndian, &length); err != nil {
 		log.Println("Event receive failed: " + err.Error())
 		return nil
 	}
 	b := make([]byte, length)
-	if _, err := io.ReadFull(conn, b); err != nil {
+	if _, err := io.ReadFull(r, b); err != nil {
 		log.Println("Event receive failed: " + err.Error())
 		return nil
 	}
@@ -60,10 +61,11 @@ func relayReadJSON(conn net.Conn) []byte {
 
 func relayMakeReceiver(ctx context.Context, conn net.Conn) <-chan []byte {
 	p := make(chan []byte, 1)
+	r := bufio.NewReader(conn)
 	go func() {
 		defer close(p)
 		for {
-			j := relayReadJSON(conn)
+			j := relayReadJSON(r)
 			if j == nil {
 				return
 			}