bench.go

package main

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

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

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

	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 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))
	}
}

benchhttp.go

package main

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

func serve(w http.ResponseWriter, r *http.Request) {
	f, err := os.Open("big.file")
	if err != nil {
		panic(err)
	}

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

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

func main() {
	go func() {
		if err := http.ListenAndServe(":8081", http.HandlerFunc(serve)); err != nil {
			panic(err)
		}
	}()

	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)
	}

	client := &http.Client{
		Transport: &http.Transport{
			MaxIdleConnsPerHost: 1024,
		},
	}

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

		resp, err := client.Get("http://localhost:8081/")
		if err != nil {
			panic(err)
		}

		if _, err := io.Copy(ioutil.Discard, resp.Body); err != nil {
			panic(err)
		}

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

		fmt.Println(time.Since(start))

		time.Sleep(time.Second)
		client.CloseIdleConnections()
	}
}

server.c

#include <fcntl.h>
#include <netinet/in.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/sendfile.h>
#include <unistd.h>

int main() {
    int ln = socket(AF_INET, SOCK_STREAM, 0);

    int enable = 1;
    if (setsockopt(ln, SOL_SOCKET, SO_REUSEADDR, &enable, sizeof(int)) < 0) {
      return -1;
    }

    struct sockaddr_in addr;
    memset(&addr, '0', sizeof(addr));

    addr.sin_family = AF_INET;
    addr.sin_addr.s_addr = htonl(INADDR_ANY);
    addr.sin_port = htons(8081);

    bind(ln, (struct sockaddr*)&addr, sizeof(addr));

    if (listen(ln, 10) == -1) {
        return -1;
    }

    int conn = accept(ln, NULL, NULL);

    while (1) {
        unsigned char buff[1];
        int nread = read(conn, buff, 1);

        if (nread != 1) {
            break;
        }

        int fd = open("big.file", O_RDONLY);
        if (fd < 0) {
            return -1;
        }

        if (sendfile(conn, fd, NULL, 1024*100) != 1024*100) {
            return -1;
        }

        if (close(fd) != 0) {
            return -1;
        }
    }

    return 0;
}