handlers

fastlog/handlers

Import path: github.com/InsideGallery/core/fastlog/handlers

handlers is the process-wide registry behind fastlog. Handler packages register either writer factories or complete slog.Handler factories, and fastlog.Config resolves configured output kinds through this registry.

Main APIs

• FormatJSON and FormatText are the supported writer-backed output formats.
• WriterFunc returns an io.Writer, optional *slog.HandlerOptions, and an error.
• HandlerFunc returns a complete slog.Handler.
• RegisterWriter(kind string, fn WriterFunc) registers writer-backed handlers.
• RegisterHandlerFunc(kind string, fn HandlerFunc) registers complete handler factories.
• Get(kind, format string, level slog.Level) returns a handler or ErrNotFoundHandler.
• ErrNotFoundHandler reports an unknown output kind.

Usage

package example

import (
	"io"
	"log/slog"
	"os"

	"github.com/InsideGallery/core/fastlog/handlers"
)

func registerStdout() {
	handlers.RegisterWriter("stdout", func() (io.Writer, *slog.HandlerOptions, error) {
		return os.Stdout, nil, nil
	})
}

func newLogger() (*slog.Logger, error) {
	handler, err := handlers.Get("stdout", handlers.FormatJSON, slog.LevelInfo)
	if err != nil {
		return nil, err
	}

	return slog.New(handler), nil
}

Operational Notes

Get checks registered HandlerFunc values first. For those handlers, the format and level parameters are handled by the factory itself. Writer-backed handlers are wrapped in slog.TextHandler for text; all other formats use slog.JSONHandler. If a writer factory returns nil options, Get applies the requested level.