From bed1d9bd27d2209c7d10d8d5d0d420b4049002e0 Mon Sep 17 00:00:00 2001
From: astaxie <xiemengjun@gmail.com>
Date: Wed, 17 Aug 2016 22:33:36 +0800
Subject: [PATCH] update the performance

---
 logs/logger.go      | 49 ++++++++++++++++++++++++++++++++++++++++++---
 logs/logger_test.go |  4 ++--
 2 files changed, 48 insertions(+), 5 deletions(-)

diff --git a/logs/logger.go b/logs/logger.go
index a8333089..1d480c07 100644
--- a/logs/logger.go
+++ b/logs/logger.go
@@ -72,10 +72,53 @@ func NewModeAnsiColorWriter(w io.Writer, mode outputMode) io.Writer {
 	return w
 }
 
+const (
+	y1  = `0123456789`
+	y2  = `0123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789`
+	y3  = `0000000000111111111122222222223333333333444444444455555555556666666666777777777788888888889999999999`
+	y4  = `0123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789`
+	mo1 = `000000000111`
+	mo2 = `123456789012`
+	d1  = `0000000001111111111222222222233`
+	d2  = `1234567890123456789012345678901`
+	h1  = `000000000011111111112222`
+	h2  = `012345678901234567890123`
+	mi1 = `000000000011111111112222222222333333333344444444445555555555`
+	mi2 = `012345678901234567890123456789012345678901234567890123456789`
+	s1  = `000000000011111111112222222222333333333344444444445555555555`
+	s2  = `012345678901234567890123456789012345678901234567890123456789`
+)
+
 func formatTimeHeader(when time.Time) ([]byte, int) {
-	_, _, d := when.Date()
-	s := when.Format("2006/01/02 15:04:05 ")
-	return []byte(s), d
+	y, mo, d := when.Date()
+	h, mi, s := when.Clock()
+	//len("2006/01/02 15:04:05 ")==20
+	var buf [20]byte
+
+	//change to '3' after 984 years, LOL
+	buf[0] = y1[y/1000%10]
+	//change to '1' after 84 years,  LOL
+	buf[1] = y2[y/100]
+	buf[2] = y3[y-y/100*100]
+	buf[3] = y4[y-y/100*100]
+	buf[4] = '/'
+	buf[5] = mo1[mo-1]
+	buf[6] = mo2[mo-1]
+	buf[7] = '/'
+	buf[8] = d1[d-1]
+	buf[9] = d2[d-1]
+	buf[10] = ' '
+	buf[11] = h1[h]
+	buf[12] = h2[h]
+	buf[13] = ':'
+	buf[14] = mi1[mi]
+	buf[15] = mi2[mi]
+	buf[16] = ':'
+	buf[17] = s1[s]
+	buf[18] = s2[s]
+	buf[19] = ' '
+
+	return buf[0:], d
 }
 
 var (
diff --git a/logs/logger_test.go b/logs/logger_test.go
index c65d70d5..119b7bd3 100644
--- a/logs/logger_test.go
+++ b/logs/logger_test.go
@@ -15,9 +15,9 @@
 package logs
 
 import (
+	"bytes"
 	"testing"
 	"time"
-	"bytes"
 )
 
 func TestFormatHeader_0(t *testing.T) {
@@ -72,4 +72,4 @@ func TestNewAnsiColor2(t *testing.T) {
 	if w1 != w2 {
 		t.Errorf("Get %#v, want %#v", w1, w2)
 	}
-}
\ No newline at end of file
+}