log.go

/*
Open Source - MIT Software License
Copyright (c) 2014 Brian Ketelsen, Skynet Authors

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/

// Package log provides syslog logging to a local or remote
// Syslog logger.  To specify a remote syslog host, set the
// "log.sysloghost" key in the Skynet configuration.  Specify
// the port with "log.syslogport".  If "log.sysloghost" is not provided,
// skynet will log to local syslog.
package log

import (
	"fmt"
	"log/syslog"
	"strconv"
)

type LogLevel int8

var syslogHost string
var syslogPort int = 0

var minLevel LogLevel
var logger *syslog.Writer

const (
	TRACE LogLevel = iota
	DEBUG
	INFO
	WARN
	ERROR
	FATAL
	PANIC
)

// Call Initialize after setting (or not setting) SyslogHost and SyslogPort when
// they're read from configuration source.
func Initialize() {

	var e error

	if len(syslogHost) > 0 {

		logger, e = syslog.New(syslog.LOG_INFO|syslog.LOG_USER, "skynet")
		if e != nil {
			panic(e)
		}
	} else {
		logger, e = syslog.Dial("tcp4", syslogHost+":"+strconv.Itoa(syslogPort), syslog.LOG_INFO|syslog.LOG_USER, "skynet")
		if e != nil {
			panic(e)
		}
	}

}

func Panic(messages ...interface{}) {
	logger.Emerg(fromMulti(messages))
}

func Panicf(format string, messages ...interface{}) {
	m := fmt.Sprintf(format, messages...)
	logger.Emerg(m)
}

func Fatal(messages ...interface{}) {
	if minLevel <= FATAL {
		logger.Crit(fromMulti(messages))
	}
}

func Fatalf(format string, messages ...interface{}) {
	if minLevel <= FATAL {
		m := fmt.Sprintf(format, messages...)
		logger.Crit(m)
	}
}

func Error(messages ...interface{}) {
	if minLevel <= ERROR {
		logger.Err(fromMulti(messages))
	}
}

func Errorf(format string, messages ...interface{}) {
	if minLevel <= ERROR {
		m := fmt.Sprintf(format, messages...)
		logger.Err(m)
	}
}

func Warn(messages ...interface{}) {
	if minLevel <= WARN {
		logger.Warning(fromMulti(messages))
	}
}

func Warnf(format string, messages ...interface{}) {
	if minLevel <= WARN {
		m := fmt.Sprintf(format, messages...)
		logger.Warning(m)
	}
}

func Info(messages ...interface{}) {
	if minLevel <= INFO {
		logger.Info(fromMulti(messages))
	}
}

func Infof(format string, messages ...interface{}) {
	if minLevel <= INFO {
		m := fmt.Sprintf(format, messages...)
		logger.Info(m)
	}
}

func Debug(messages ...interface{}) {
	if minLevel <= DEBUG {
		logger.Debug(fromMulti(messages))
	}
}

func Debugf(format string, messages ...interface{}) {
	if minLevel <= DEBUG {
		m := fmt.Sprintf(format, messages...)
		logger.Debug(m)
	}
}

func Trace(messages ...interface{}) {
	if minLevel <= TRACE {
		logger.Debug(fromMulti(messages))
	}
}

func Tracef(format string, messages ...interface{}) {
	if minLevel <= TRACE {
		m := fmt.Sprintf(format, messages...)
		logger.Debug(m)
	}
}

func Println(level LogLevel, messages ...interface{}) {

	switch level {
	case DEBUG:
		Debugf("%v", messages)
	case TRACE:
		Tracef("%v", messages)
	case INFO:
		Infof("%v", messages)
	case WARN:
		Warnf("%v", messages)
	case ERROR:
		Errorf("%v", messages)
	case FATAL:
		Fatalf("%v", messages)
	case PANIC:
		Panicf("%v", messages)
	}

	return
}

func Printf(level LogLevel, format string, messages ...interface{}) {

	switch level {
	case DEBUG:
		Debugf(format, messages)
	case TRACE:
		Tracef(format, messages)
	case INFO:
		Infof(format, messages)
	case WARN:
		Warnf(format, messages)
	case ERROR:
		Errorf(format, messages)
	case FATAL:
		Fatalf(format, messages)
	case PANIC:
		Panicf(format, messages)
	}

	return
}

func SetSyslogHost(host string) {
	syslogHost = host
}

func SetSyslogPort(port int) {
	syslogPort = port
}

func SetLogLevel(level LogLevel) {
	minLevel = level
}

func GetLogLevel() LogLevel {
	return minLevel
}

func fromMulti(messages ...interface{}) string {
	var r string
	for x := 0; x < len(messages); x++ {
		r = r + messages[x].(string)
		if x < len(messages) {
			r = r + "  "
		}
	}
	return r
}

func LevelFromString(l string) (level LogLevel) {
	switch l {
	case "DEBUG":
		level = DEBUG
	case "TRACE":
		level = TRACE
	case "INFO":
		level = INFO
	case "WARN":
		level = WARN
	case "ERROR":
		level = ERROR
	case "FATAL":
		level = FATAL
	case "PANIC":
		level = PANIC
	}

	return
}