5.3 سرور tcp پیشرفته

  1package main
  2
  3import (
  4	"bytes"
  5	"crypto/rand"
  6	"encoding/binary"
  7	"fmt"
  8	"io"
  9	"log"
 10	"net"
 11	"time"
 12)
 13
 14
 15type FileServer struct { }
 16
 17
 18func (fs *FileServer) start() {
 19	ln, err := net.Listen("tcp", "0.0.0.0:3000")
 20	if err != nil {
 21		panic(err)
 22	}
 23
 24	for {
 25		conn, err := ln.Accept()
 26
 27		if err != nil {
 28			log.Fatal(err)
 29			continue
 30		}
 31
 32		fmt.Printf("new connection: %s\n", conn.RemoteAddr().String())
 33
 34		// read data from accepted connections
 35		go fs.readLoop(conn)
 36	}
 37}
 38
 39func (fs *FileServer) readLoop(conn net.Conn) {
 40
 41	// make a new buffer
 42	buf := new(bytes.Buffer)
 43
 44	for {
 45 
 46		var size int64
 47  
 48		// get the size from connection
 49		binary.Read(conn, binary.LittleEndian, &size)
 50
 51		// copy from connection until the end of file
 52		n, err := io.CopyN(buf, conn, size)
 53		if err != nil {
 54			log.Fatal(err)
 55			continue
 56		}
 57
 58		fmt.Println(buf.Bytes())
 59		fmt.Printf("received %d bytes over the network\n", n)
 60	}
 61}
 62
 63func main() {
 64
 65	go func ()  {
 66 
 67		time.Sleep(4 * time.Second)
 68  
 69    // set your file szie
 70		sendFile(2000000)
 71	}()
 72
 73	s := &FileServer{}
 74	s.start()
 75}
 76
 77// client example that send a large file to server!
 78func sendFile(size int) error {
 79
 80	file := make([]byte, size)
 81
 82	// make a random file from the size provided
 83	_, err := io.ReadFull(rand.Reader, file)
 84	if err != nil {
 85		return err
 86	}
 87
 88	// dial with the tcp server (you can do this is an other file)
 89	conn, err := net.Dial("tcp", ":3000")
 90	if err != nil {
 91		return err
 92	}
 93
 94	// send the size of file
 95	binary.Write(conn, binary.LittleEndian, int64(size))
 96
 97	// copy file over the network until the end of file
 98	n, err := io.CopyN(conn, bytes.NewReader(file), int64(size))
 99	if err != nil {
100		return err
101	}
102
103	fmt.Printf("written %d byte over the network\n", n)
104	return nil
105}