diff --git a/README.md b/README.md
index b4edc1e..0c0f8e8 100644
--- a/README.md
+++ b/README.md
@@ -6,7 +6,7 @@ A simple benchmark testing tool implemented in golang, the basic functions refer
 - simple code, easy to change
 ## Building
 
-```
+```shell script
 git clone git://github.com/cnlh/benchmark.git
 cd benchmark
 go build
@@ -14,12 +14,12 @@ go build
 ## Usage
 
 basic usage is quite simple:
-```
+```shell script
 benchmark [flags] url
 ```
 
 with the flags being
-```
+```shell script
     -b string
       	the body of request
     -c int
@@ -40,7 +40,7 @@ with the flags being
     	proxy of request
 ```
 for example
-```
+```shell script
 benchmark -c 1100 -n 1000000  http://127.0.0.1/
 ```
 
diff --git a/benchmark.go b/benchmark.go
index 706fc09..2ba5471 100644
--- a/benchmark.go
+++ b/benchmark.go
@@ -1,3 +1,7 @@
+// Copyright 2020 The benchmark. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
 package main
 
 import (
@@ -8,6 +12,7 @@ import (
 	"time"
 )
 
+// benchmark is used to manager connection and deal with the result
 type benchmark struct {
 	connectionNum int
 	reqNum        int64
@@ -23,6 +28,7 @@ type benchmark struct {
 	reqConnList   []*ReqConn
 }
 
+// Start benchmark with the param has setting
 func (pf *benchmark) Run() {
 	fmt.Printf("Running %d test @ %s by %d connections\n", pf.reqNum, pf.target, pf.connectionNum)
 	var err error
@@ -54,6 +60,7 @@ func (pf *benchmark) Run() {
 	return
 }
 
+// Print the result of benchmark on console
 func (pf *benchmark) Print() {
 	readAll := 0
 	writeAll := 0
@@ -65,10 +72,10 @@ func (pf *benchmark) Print() {
 		allTimes = append(allTimes, v.reqTimes...)
 		allError += v.ErrorTimes
 	}
-	second := pf.endTime.Sub(pf.startTime).Seconds()
-	fmt.Printf("%d requests in %.2fs, %s read, %s write\n", pf.reqNum, second, formatFlow(float64(readAll)), formatFlow(float64(writeAll)))
-	fmt.Printf("Requests/sec: %.2f\n", float64(pf.reqNum)/second)
-	fmt.Printf("Transfer/sec: %s\n", formatFlow(float64(readAll+writeAll)/second))
+	runSecond := pf.endTime.Sub(pf.startTime).Seconds()
+	fmt.Printf("%d requests in %.2fs, %s read, %s write\n", pf.reqNum, runSecond, formatFlow(float64(readAll)), formatFlow(float64(writeAll)))
+	fmt.Printf("Requests/sec: %.2f\n", float64(pf.reqNum)/runSecond)
+	fmt.Printf("Transfer/sec: %s\n", formatFlow(float64(readAll+writeAll)/runSecond))
 	fmt.Printf("Error       : %d\n", allError)
 	sort.Ints(allTimes)
 	rates := []int{50, 65, 75, 80, 90, 95, 98, 99, 100}
@@ -78,6 +85,7 @@ func (pf *benchmark) Print() {
 	}
 }
 
+// Format the flow data
 func formatFlow(size float64) string {
 	var rt float64
 	var suffix string
@@ -87,7 +95,6 @@ func formatFlow(size float64) string {
 		MByte = KByte * 1024
 		GByte = MByte * 1024
 	)
-
 	if size > GByte {
 		rt = size / GByte
 		suffix = "GB"
@@ -101,7 +108,5 @@ func formatFlow(size float64) string {
 		rt = size
 		suffix = "bytes"
 	}
-
-	srt := fmt.Sprintf("%.2f%v", rt, suffix)
-	return srt
+	return fmt.Sprintf("%.2f%v", rt, suffix)
 }
diff --git a/benchmark_test.go b/benchmark_test.go
new file mode 100644
index 0000000..eb74521
--- /dev/null
+++ b/benchmark_test.go
@@ -0,0 +1,42 @@
+package main
+
+import (
+	"io"
+	"net/http"
+	"net/http/httputil"
+	"testing"
+	"time"
+)
+
+func TestMain(m *testing.M) {
+	// create a http server
+	http.HandleFunc("/", func(writer http.ResponseWriter, request *http.Request) {
+		io.WriteString(writer, "work well!")
+	})
+	go http.ListenAndServe(":15342", nil)
+	time.Sleep(time.Second)
+	m.Run()
+}
+
+func TestBenchmark_Run(t *testing.T) {
+	// create a request
+	r, err := http.NewRequest("GET", "http://127.0.0.0.1:15342", nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	writeBytes, err := httputil.DumpRequest(r, true)
+	if err != nil {
+		t.Fatal(err)
+	}
+	p := &benchmark{
+		connectionNum: 100,
+		reqNum:        20000,
+		requestBytes:  writeBytes,
+		target:        "127.0.0.1:15342",
+		schema:        r.URL.Scheme,
+		timeout:       30000,
+		reqConnList:   make([]*ReqConn, 0),
+	}
+	p.Run()
+	p.Print()
+}
diff --git a/connection.go b/connection.go
index 8d6d5f0..8fbf264 100644
--- a/connection.go
+++ b/connection.go
@@ -1,3 +1,7 @@
+// Copyright 2020 The benchmark. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
 package main
 
 import (
@@ -17,12 +21,13 @@ import (
 )
 
 var (
-	rawBytes = []byte("\r\n\r\n")
-	rowBytes = []byte("\r\n")
-	lenBytes = []byte("Content-Length: ")
-	l        = len(lenBytes)
+	bodyHeaderSepBytes    = []byte{13, 10, 13, 10}
+	bodyHeaderSepBytesLen = 4
+	headerSepBytes        = []byte{13, 10}
+	contentLengthBytes    = []byte{67, 111, 110, 116, 101, 110, 116, 45, 76, 101, 110, 103, 116, 104, 58, 32}
+	contentLengthBytesLen = 16
 )
-
+// ReqConn is used to create a connection and record data
 type ReqConn struct {
 	ErrorTimes int
 	Count      int64
@@ -39,6 +44,8 @@ type ReqConn struct {
 	proxy      string
 }
 
+// Connect to the server, http and socks5 proxy support
+// If the target is https, convert connection to tls client
 func (rc *ReqConn) dial() error {
 	if rc.conn != nil {
 		rc.conn.Close()
@@ -79,6 +86,7 @@ func (rc *ReqConn) dial() error {
 	return nil
 }
 
+// Start a connection, send request to server and read response from server
 func (rc *ReqConn) Start() (err error) {
 	var contentLen string
 	var bodyHasRead int
@@ -110,16 +118,16 @@ re:
 		headerHasRead += n
 		rc.readLen += n
 		var bbArr [2][]byte
-		bodyPos := bytes.Index(rc.buf[:headerHasRead], rawBytes)
+		bodyPos := bytes.Index(rc.buf[:headerHasRead], bodyHeaderSepBytes)
 		if bodyPos > -1 {
 			bbArr[0] = rc.buf[:bodyPos]
-			bbArr[1] = rc.buf[bodyPos+len(rawBytes):]
+			bbArr[1] = rc.buf[bodyPos+bodyHeaderSepBytesLen:]
 		} else {
 			goto readHeader
 		}
-		n := bytes.Index(bbArr[0], lenBytes)
-		start := n + l
-		end := bytes.Index(bbArr[0][start:], rowBytes)
+		n := bytes.Index(bbArr[0], contentLengthBytes)
+		start := n + contentLengthBytesLen
+		end := bytes.Index(bbArr[0][start:], headerSepBytes)
 		if end == -1 {
 			contentLen = Bytes2str(bbArr[0][start:])
 		} else {
@@ -145,10 +153,12 @@ re:
 	}
 }
 
+// Convert bytes to strings
 func Bytes2str(b []byte) string {
 	return *(*string)(unsafe.Pointer(&b))
 }
 
+// Create a connection by http proxy server
 func NewHttpProxyConn(url *url.URL, remoteAddr string) (net.Conn, error) {
 	req, err := http.NewRequest("CONNECT", "http://"+remoteAddr, nil)
 	if err != nil {
@@ -156,7 +166,6 @@ func NewHttpProxyConn(url *url.URL, remoteAddr string) (net.Conn, error) {
 	}
 	password, _ := url.User.Password()
 	req.SetBasicAuth(url.User.Username(), password)
-	// we make a http proxy request
 	proxyConn, err := net.Dial("tcp", url.Host)
 	if err != nil {
 		return nil, err
diff --git a/main.go b/main.go
index 15432c5..ac0211d 100644
--- a/main.go
+++ b/main.go
@@ -1,3 +1,7 @@
+// Copyright 2020 The benchmark. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
 package main
 
 import (
@@ -5,6 +9,7 @@ import (
 	"fmt"
 	"net/http"
 	"net/http/httputil"
+	"net/url"
 	"runtime"
 	"strings"
 )
@@ -23,6 +28,10 @@ var (
 
 func main() {
 	flag.Parse()
+	if u, err := url.Parse(flag.Arg(0)); err != nil || u.Host == "" {
+		fmt.Printf("the request url %s is not correct \n", flag.Arg(0))
+		return
+	}
 	payload := strings.NewReader(*body)
 	req, err := http.NewRequest(*method, flag.Arg(0), payload)
 	if err != nil {