feat add a go tool

.gitignore

@@ -15,4 +15,5 @@
 # Dependency directories (remove the comment below to include it)
 # vendor/
 
-.vscode
+.vscode
+*.log

go/readdelay/main.go

@@ -0,0 +1,137 @@
+package main
+
+import (
+	"bufio"
+	"flag"
+	"fmt"
+	"io"
+	"log"
+	"os"
+	"strconv"
+	"strings"
+)
+
+const (
+	Send = "二进制消息	2.6 kB"
+	Recieve = "二进制消息	3.9 kB"
+	Broadcast = "二进制消息	16 B"
+)
+
+type message struct {
+	Type int
+	Size int
+	Time int64
+}
+
+func time2int64(t string)int64{
+	strs := strings.Split(t, ":")
+	if len(strs) != 3 {
+		return 0
+	}
+	hour := strs[0]
+	minute := strs[1]
+	seconds := strings.Split(strs[2], ".")
+	if len(seconds) != 2 {
+		return 0
+	}
+	second := seconds[0]
+	mill := seconds[1]
+	
+	ms, err := strconv.ParseInt(mill, 10, 64)
+	if err != nil {
+		log.Println(err)
+		return 0
+	}
+	h, err := strconv.ParseInt(hour, 10, 64)
+	if err != nil {
+		log.Println(err)
+		return 0
+	}
+	ms = ms + h *3600*1000
+	m, err := strconv.ParseInt(minute, 10, 64)
+	if err != nil {
+		log.Println(err)
+		return 0
+	}
+	ms = ms + m * 60 *1000
+	s, err := strconv.ParseInt(second, 10, 64)
+	if err != nil {
+		log.Println(err)
+		return 0
+	}
+	ms = ms + s *1000
+	return ms
+}
+
+func readdelay(file string)([]message, error){
+	f, err := os.Open(file)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+	reader := bufio.NewReader(f)
+	res := []message{}
+	t := 0
+	for {
+		line, err := reader.ReadString('\n')
+		if err != nil {
+			if err == io.EOF {
+				return res, nil
+			}
+			return res, err
+		}
+		line = strings.Trim(strings.Trim(strings.Trim(line, " "), "\t"), "\n")
+		switch {
+		case strings.Contains(line, Send):
+			t = 1
+		case  strings.Contains(line, Recieve):
+			t = 2
+		case  strings.Contains(line, Broadcast):
+			t = 3
+		default:
+			msg := message{Type: t, Time: time2int64(line)}
+			switch t {
+			case 1 :
+				res = append(res, msg)
+			case 2:
+				res = append(res, msg)
+			}
+			t = 0
+		}
+	}
+}
+
+func avg(delays ...int64)int64{
+	if len(delays) == 0 {
+		return 0
+	}
+	var total int64
+	for _, d := range delays {
+		total = total + d
+	}
+	return total/int64(len(delays))
+}
+
+func main(){
+	var file string
+	flag.StringVar(&file, "f", "delay.log", "ssss")
+	flag.Parse()
+	messages, err := readdelay(file)
+	if err != nil {
+		log.Fatal(err)
+	}
+	log.Println("got ", len(messages), " messages")
+	delays := []int64{}
+	var start int64
+	for _, msg := range messages {
+		if msg.Type == 1 {
+			start = msg.Time
+		}
+		if start != 0 && msg.Type == 2 {
+			delay := msg.Time - start
+			start = 0
+			delays = append(delays, delay)
+		}
+	}
+	fmt.Println(avg(delays...))
+}