修正 ms 显示格式，File Rotating 模式支持续写，如果文件已存在不对上次内容进行覆盖，而是从文件结尾继续往下写，或直接写下一个文件。

Signed-off-by: rick.chan <cy@haoan119.com>

.gitignore

@@ -1 +1,3 @@
 .vscode/settings.json
+*.log
+*.log.*

README.md

@@ -0,0 +1,3 @@
+# Simple Log
+
+A very simple log system(golang).

demo/main.go

@@ -1,11 +1,17 @@
 package main
 
 import (
+	"time"
+
 	"github.com/lion187chen/simplelog"
 )
 
 var sl *simplelog.SimpleLog
 
 func main() {
-	sl = new(simplelog.SimpleLog).InitRotating("./log/MS.log", 1024*1024*2, 100, simplelog.LevelTrace)
+	sl = new(simplelog.SimpleLog).InitRotating("./log/MS.log", 1024*10, 10, simplelog.LevelTrace)
+	for i := 0; i < 10000000; i++ {
+		sl.Debug("hello world")
+		time.Sleep(8 * time.Millisecond)
+	}
 }

filehandler.go

@@ -2,6 +2,7 @@ package simplelog
 
 import (
 	"fmt"
+	"io"
 	"os"
 	"path"
 	"time"
@@ -58,6 +59,10 @@ type RotatingFileHandler struct {
 }
 
 func (h *RotatingFileHandler) InitRotating(name string, maxBytes int, backupCount int) (*RotatingFileHandler, error) {
+	h.fileName = name
+	h.maxBytes = maxBytes
+	h.backupCount = backupCount
+
 	if isFileExist(name) {
 		var err error
 		h.fd, err = os.OpenFile(name, os.O_CREATE|os.O_RDONLY, 0666)
@@ -69,12 +74,12 @@ func (h *RotatingFileHandler) InitRotating(name string, maxBytes int, backupCoun
 			h.fd.Close()
 			return nil, err
 		}
-		if f.Size() > 0 {
-			h._doRollover()
-			return h, nil
+		if f.Size() < int64(h.maxBytes) {
+			h.fd.Seek(0, io.SeekEnd)
 		} else {
-			h.fd.Close()
+			h._doRollover()
 		}
+		return h, nil
 	}
 
 	dir := path.Dir(name)
@@ -84,10 +89,6 @@ func (h *RotatingFileHandler) InitRotating(name string, maxBytes int, backupCoun
 		return nil, fmt.Errorf("invalid max bytes")
 	}
 
-	h.fileName = name
-	h.maxBytes = maxBytes
-	h.backupCount = backupCount
-
 	var err error
 	h.fd, err = os.OpenFile(name, os.O_CREATE|os.O_WRONLY, 0666)
 	if err != nil {