package log
import (
"fmt"
"io"
"log"
"os"
"strings"
)
type LogLevel int
const (
TRACE LogLevel = 5
DEBUG LogLevel = 10
INFO LogLevel = 20
WARN LogLevel = 30
ERROR LogLevel = 40
)
var (
trace *log.Logger
dbg *log.Logger
info *log.Logger
warn *log.Logger
err *log.Logger
minLevel LogLevel = TRACE
)
func Init(file *os.File, level LogLevel) {
minLevel = level
flags := log.Ldate | log.Ltime | log.Lmicroseconds | log.Lshortfile
if file != nil {
trace = log.New(file, "TRACE ", flags)
dbg = log.New(file, "DEBUG ", flags)
info = log.New(file, "INFO ", flags)
warn = log.New(file, "WARN ", flags)
err = log.New(file, "ERROR ", flags)
}
}
func ParseLevel(value string) (LogLevel, error) {
switch strings.ToLower(value) {
case "trace":
return TRACE, nil
case "debug":
return DEBUG, nil
case "info":
return INFO, nil
case "warn", "warning":
return WARN, nil
case "err", "error":
return ERROR, nil
}
return 0, fmt.Errorf("%s: invalid log level", value)
}
func ErrorLogger() *log.Logger {
if err == nil {
return log.New(io.Discard, "", log.LstdFlags)
}
return err
}
type Logger interface {
Tracef(string, ...interface{})
Debugf(string, ...interface{})
Infof(string, ...interface{})
Warnf(string, ...interface{})
Errorf(string, ...interface{})
}
type logger struct {
name string
calldepth int
}
func NewLogger(name string, calldepth int) Logger {
return &logger{name: name, calldepth: calldepth}
}
func (l *logger) format(message string, args ...interface{}) string {
if len(args) > 0 {
message = fmt.Sprintf(message, args...)
}
if l.name != "" {
message = fmt.Sprintf("[%s] %s", l.name, message)
}
return message
}
func (l *logger) Tracef(message string, args ...interface{}) {
if trace == nil || minLevel > TRACE {
return
}
message = l.format(message, args...)
trace.Output(l.calldepth, message) //nolint:errcheck // we can't do anything with what we log
}
func (l *logger) Debugf(message string, args ...interface{}) {
if dbg == nil || minLevel > DEBUG {
return
}
message = l.format(message, args...)
dbg.Output(l.calldepth, message) //nolint:errcheck // we can't do anything with what we log
}
func (l *logger) Infof(message string, args ...interface{}) {
if info == nil || minLevel > INFO {
return
}
message = l.format(message, args...)
info.Output(l.calldepth, message) //nolint:errcheck // we can't do anything with what we log
}
func (l *logger) Warnf(message string, args ...interface{}) {
if warn == nil || minLevel > WARN {
return
}
message = l.format(message, args...)
warn.Output(l.calldepth, message) //nolint:errcheck // we can't do anything with what we log
}
func (l *logger) Errorf(message string, args ...interface{}) {
if err == nil || minLevel > ERROR {
return
}
message = l.format(message, args...)
err.Output(l.calldepth, message) //nolint:errcheck // we can't do anything with what we log
}
var root = logger{calldepth: 3}
func Tracef(message string, args ...interface{}) {
root.Tracef(message, args...)
}
func Debugf(message string, args ...interface{}) {
root.Debugf(message, args...)
}
func Infof(message string, args ...interface{}) {
root.Infof(message, args...)
}
func Warnf(message string, args ...interface{}) {
root.Warnf(message, args...)
}
func Errorf(message string, args ...interface{}) {
root.Errorf(message, args...)
}
