You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: logger.go
    path of file: ./repos/vault/helper/logging
    
    the code of the file until where you have to start completion: // Copyright (c) HashiCorp, Inc.
// SPDX-License-Identifier: BUSL-1.1

package logging

import (
	"errors"
	"fmt"
	"io"
	"path/filepath"
	"strings"
	"time"

	"github.com/hashicorp/go-hclog"
	"github.com/hashicorp/go-multierror"
)

const (
	UnspecifiedFormat LogFormat = iota
	StandardFormat
	JSONFormat
)

// defaultRotateDuration is the default time taken by the agent to rotat
    
func parseFullPath(fullPath string) (directory, fileName string, err error) {
	directory, fileName = filepath.Split(fullPath)

	globChars := "*?["
	if strings.ContainsAny(directory, globChars) {
		err = multierror.Append(err, fmt.Errorf("directory contains glob character"))
	}
	if fileName == "" {
		fileName = "vault.log"
	} else if strings.ContainsAny(fileName, globChars) {
		err = multierror.Append(err, fmt.Errorf("file name contains globbing character"))
	}

	return directory, fileName, err
}