a3linux/daslog

Go (golang) simple logger package.

DASLOG

Daslog is a simple logger package for Go (golang) programms.

DAmn Simple LOGger.

go get -u github.com/iu0v1/daslog

Why?

Yes. This is yet another logger. I made this package, because any other logger that I met - is a monster. They can do a lot of tricks, with one exception - a simple and transparent logging. Sometimes, you need only logging, without the possibility of launching a space shuttle through the services of Amazon or Google.

Prefix format

You can use some GNU date format commands in prefix line.

'GNU date' compatible format commands:

{{.F}} - full date                               (2016-01-04)
{{.T}} - time                                    (16:52:36)
{{.r}} - 12-hour clock time                      (11:11:04 PM)
{{.Y}} - year                                    (2016)
{{.y}} - last two digits of year                 (00..99)
{{.m}} - month                                   (01..12)
{{.b}} - locale's abbreviated month name         (Jan)
{{.B}} - locale's full month name                (January)
{{.d}} - day of month                            (01)
{{.a}} - locale's abbreviated weekday name       (Sun)
{{.A}} - locale's full weekday name              (Sunday)
{{.H}} - 24-hour clock hour                      (00..23)
{{.I}} - 12-hour clock hour                      (01..12)
{{.M}} - minute                                  (00..59)
{{.S}} - second                                  (00..60)
{{.p}} - locale's equivalent of either AM or PM  (AM)

Incompatible format commands:

{{.O}} - same as {{.F}} + {{.T}}                 (2016-01-04 16:52:36)
{{.Q}} - message urgency level                   (info, critical, etc)

Simple example

package main

import (
	"fmt"
	"os"

	"github.com/iu0v1/daslog"
)

func main() {
	o := daslog.Options{
		Destination: os.Stdout,
		Prefix:      "{{.O}} [{{.Q}}]: ",
		LogLevel:    daslog.UrgencyLevelCritical,
	}

	l, err := daslog.New(o)
	if err != nil {
		fmt.Print(err)
		return
	}

	// notice in Log style
	l.Log(daslog.UrgencyLevelNotice, "test notice message")

	// info
	l.Info("test info message")

	// error
	l.Errorf("%s %s %s", "test", "error", "message")
}

Output:

2016-01-04 21:16:41 [notice]: test notice message
2016-01-04 21:16:41 [info]: test info message
2016-01-04 21:16:42 [error]: test error message

Performance

Compare with a log package.

Daslog equal to a log, when you use a pure prefix; in ~2x slower, if you use format options in a prefix; in ~2.5x slower if you use {{.Q}} option in a prefix. Avoid to use Daslog, if you need high performance.

BenchmarkLog-4                         2000000       836 ns/op       137 B/op       2 allocs/op
BenchmarkDaslogPurePrefix-4            2000000       704 ns/op       106 B/op       4 allocs/op
BenchmarkDaslogTemplatePrefix-4        1000000      1369 ns/op       199 B/op       5 allocs/op
BenchmarkDaslogTemplatePrefixQ-4       1000000      1792 ns/op       270 B/op       7 allocs/op

DOC

For more infomation, please look at the examples and read the doc.