nbio sendfile on linux

bench.go

package main

import (
	"fmt"
	"io"
	"io/ioutil"
	"net"
	"os"
	"time"

	"github.com/lesismal/nbio"
)

func server() {
	g := nbio.NewGopher(nbio.Config{
		Network: "tcp",
		Addrs:   []string{"localhost:8081"},
	})

	g.OnData(func(c *nbio.Conn, data []byte) {
		fd, err := os.Open("big.file")
		if err != nil {
			panic(err)
		}

		if _, err = c.Sendfile(fd, 0); err != nil {
			panic(err)
		}

		if err := fd.Close(); err != nil {
			panic(err)
		}
	})

	err := g.Start()
	if err != nil {
		fmt.Printf("nbio.Start failed: %v\n", err)
		return
	}
}

func main() {
	if len(os.Args) < 2 || os.Args[1] != "noserver" {
		go server()
	}

	time.Sleep(time.Millisecond * 100) // Give the server some time to start.

	if err := ioutil.WriteFile("big.file", make([]byte, 1024*100), 0666); err != nil {
		panic(err)
	}

	conn, err := net.Dial("tcp", "localhost:8081")
	if err != nil {
		panic(err)
	}

	buf := make([]byte, 1024*100)

	for i := 0; i < 10; i++ {
		start := time.Now()

		if _, err := conn.Write([]byte{1}); err != nil {
			panic(err)
		}

		if _, err := io.ReadFull(conn, buf); err != nil {
			panic(err)
		}

		fmt.Println(time.Since(start))
	}
}

bench_readbuffer.go

package main

import (
	"fmt"
	"io"
	"io/ioutil"
	"net"
	"os"
	"time"
)

func server() {
	ln, err := net.Listen("tcp", ":8081")
	if err != nil {
		panic(err)
	}

	for {
		conn, err := ln.Accept()
		if err != nil {
			panic(err)
		}

		go func() {
			for {
				buf := make([]byte, 1)
				if _, err := conn.Read(buf); err != nil {
					return
				}

				fd, err := os.Open("big.file")
				if err != nil {
					panic(err)
				}

				if _, err = io.Copy(conn, fd); err != nil {
					panic(err)
				}

				if err := fd.Close(); err != nil {
					panic(err)
				}
			}
		}()
	}
}

func readfile(conn *net.TCPConn) {
	buf := make([]byte, 1024*100)

	for i := 0; i < 10; i++ {
		start := time.Now()

		if _, err := conn.Write([]byte{1}); err != nil {
			panic(err)
		}

		if _, err := io.ReadFull(conn, buf); err != nil {
			panic(err)
		}

		fmt.Println(time.Since(start))
	}
}

func main() {
	if len(os.Args) < 2 || os.Args[1] != "noserver" {
		go server()
	}

	time.Sleep(time.Millisecond * 100) // Give the server some time to start.

	if err := ioutil.WriteFile("big.file", make([]byte, 1024*100), 0666); err != nil {
		panic(err)
	}

	conn, err := net.Dial("tcp", "localhost:8081")
	if err != nil {
		panic(err)
	}
	tcpConn := conn.(*net.TCPConn)
	fmt.Println("default read buffer:")
	readfile(tcpConn)

	fmt.Println("\nread buffer 1024*1000:")
	conn, err = net.Dial("tcp", "localhost:8081")
	if err != nil {
		panic(err)
	}
	tcpConn = conn.(*net.TCPConn)
	tcpConn.SetReadBuffer(1024 * 1000)
	readfile(tcpConn)
}