circularlogger

CircularLogger: A Thread-Safe Circular Buffer Logger for Go

Description

CircularLogger is a Go package that provides a thread-safe logging mechanism using a circular buffer. It is designed to store a fixed number of log entries, making it ideal for applications where memory usage needs to be controlled. The logger supports multiple log levels (TRACE, INFO, WARN, FATAL), optional file and line information, and customizable log formatting, including JSON output.

Motivation

I want to be able to log within packages. The standard to build go apps should be to write packages and one or more simple "mains" in cmd/... I like this approach but logging was always a bit of a painpoint since writing somewhere would need to make assumptions I don't want make when in package. Storing in memory creates the risk that it will be hogging a potentially infinite amount of ram depending on how its used. A circular buffer will never take more than what has initially been assigned to it. You decide how many entries you want to keep.

Features

• Thread-safe logging
• Circular buffer to limit the number of stored logs
• Support for log levels: TRACE, INFO, WARN, FATAL
• Optional inclusion of file name and line number in logs
• Customizable log formatting, including JSON
• Methods for formatted logging (e.g., Infof, Warnf)

Installation

To use CircularLogger in your Go project, first ensure your project is set up as a Go module:

go get codeberg.org/slaxor/circularlogger

Usage

In your package you can do this:

package thefoo

import (
	"codeberg.org/slaxor/circularlogger"
)

var log = circularlogger.NewCircularLogger(10)
var Log = log

func init() {
	log.SetShortFile(true)                         // Enable file and line info
	log.SetFormatter(circularlogger.AnsiFormatter) // Color lines
	log.SetLevel(circularlogger.DEBUG)             // Log debug or more severe
}

func Foo(s string) {
	log.Debugf("called Foo(%q)", s)
}

And then in your main:

package main

import (
	"fmt"
	"thefoo"
)

func main() {
	thefoo.Foo("bar")
	fmt.Print(thefoo.Log.String())
}

A nice trick to do realtime logging is:

package main

import (
	"context"
	"thefoo"
)

func main() {
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()
	thefoo.Log.Watch(ctx)
	for i := range 12 {
		thefoo.Foo("bar")
		thefoo.Log.Infof("% 2d", i)
	}
}

License

This is free software it can be used in any way the Gnu General Public License allows. You may want to have a look at it here