一个logger代码，大家帮忙指正

刚上手golang的时候看log库，为了练手就写了个logger库自己用 主要是设定几个日志级别，然后可以按照大小轮转日志，并限定日志个数。 ####模拟linux的syslog轮转xxx.log.1 xxx.log.2 .... 这样 ####希望大家帮忙看看，有什么问题，谢谢 ####logger.go package logger import ( "fmt" "os" "sync" "path/filepath" "strings" "strconv" "time" "runtime" ) // 检查文件或目录是否存在 // 如果由 filename 指定的文件或目录存在则返回 true，否则返回 false func Exist(filename string) bool { _, err := os.Stat(filename) return err == nil || os.IsExist(err) } type level int const ( DetailLog level = iota DebugLog InfoLog WarnLog ErrorLog PanicLog LevelNum = 6 ) const levelChar = "TDIWEP" var levelName = []string{ DetailLog: "DETAIL", DebugLog: "DEBUG", InfoLog: "INFO", WarnLog: "WARN", ErrorLog: "ERROR", PanicLog: "PANIC", } var logging = &loggingT{toStderr:true, outputLevel:DetailLog, w:os.Stderr} func SetLevel(l level) { logging.outputLevel = l } func SetRotatingFile(path string, maxBytes int64, backCount int) bool { dir := filepath.Dir(path) if !strings.EqualFold(dir, ".") { if err := os.MkdirAll(dir, 0755); err != nil { fmt.Printf("ERROR - MkdirAll(%s): %s\n", dir, err.Error()) return false } } f, err := os.OpenFile(path, os.O_WRONLY|os.O_CREATE|os.O_APPEND, 0644) if err != nil { fmt.Printf("ERROR - OpenFile(%s): %s\n", path, err.Error()) return false } logging.toStderr = false logging.filename = path logging.w = f logging.maxBytes = maxBytes logging.backCount = backCount //fmt.Printf("%#v", logging) return true } func Detail(format string, v ...interface{}) { logging.printf(DetailLog, format, v...) } func Debug(format string, v ...interface{}) { logging.printf(DebugLog, format, v...) } func Info(format string, v ...interface{}) { logging.printf(InfoLog, format, v...) } func Warn(format string, v ...interface{}) { logging.printf(WarnLog, format, v...) } func Error(format string, v ...interface{}) { logging.printf(ErrorLog, format, v...) } func Panic(format string, v ...interface{}) { logging.printf(PanicLog, format, v...) } // loggingT collects all the global state of the logging setup. type loggingT struct { // 是否打印到终端 toStderr bool // 日志的输出级别 outputLevel level // mu protects the remaining elements of this structure and is // used to synchronize logging. mu sync.Mutex // 日志文件名称 用于打开文件和轮转日志 filename string // 写日志的对象 //文件对象 w *os.File // 保留的日志个数 main.log.1 backCount int // 单文件大小 maxBytes int64 } func (self *loggingT) rotatingFile() { self.w.Close() self.w = nil for i := self.backCount; i >= 0; i-- { backFilename := self.filename + "." + strconv.Itoa(i) backFilename_obj := self.filename + "." + strconv.Itoa(i+1) if i > 0 && !Exist(backFilename) { continue } if i == self.backCount { os.Remove(backFilename) } else if i == 0 { os.Rename(self.filename, backFilename_obj) } else { os.Rename(backFilename, backFilename_obj) } } f, err := os.OpenFile(self.filename, os.O_WRONLY|os.O_CREATE|os.O_APPEND, 0644) if err != nil { println(err) return } self.w = f } func (self *loggingT) printf(l level, format string, v ...interface{}) { if self.outputLevel > l { return } msg := fmt.Sprintf(format, v...) self.mu.Lock() defer self.mu.Unlock() if self.toStderr == false { info, err := self.w.Stat(); if err == nil && info.Size() >= self.maxBytes { self.rotatingFile() } } _, file, line, ok := runtime.Caller(2) if !ok { file = "???" line = 1 } else { slash := strings.LastIndex(file, "/") if slash >= 0 { file = file[slash+1:] } } fmt.Fprintf(self.w, "%s %s - %s [%s:%d]\n", time.Now().Format("2006-01-02 15:04:05"), levelName[l], msg, file, line) } ####logger_test.go package logger import ( "testing" ) func TestNormal(t *testing.T) { SetLevel(DetailLog) Detail("%d", DetailLog) Debug("%d", DebugLog) Info("%d", InfoLog) Error("%d", ErrorLog) Panic("%d", PanicLog) }