maddy/framework/log/writer.go

95 lines
3 KiB
Go

/*
Maddy Mail Server - Composable all-in-one email server.
Copyright © 2019-2020 Max Mazurov <fox.cpp@disroot.org>, Maddy Mail Server contributors
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
package log
import (
"fmt"
"io"
"os"
"strings"
"time"
)
type wcOutput struct {
timestamps bool
wc io.WriteCloser
}
func (w wcOutput) Write(stamp time.Time, debug bool, msg string) {
builder := strings.Builder{}
if w.timestamps {
builder.WriteString(stamp.UTC().Format("2006-01-02T15:04:05.000Z "))
}
if debug {
builder.WriteString("[debug] ")
}
builder.WriteString(msg)
builder.WriteRune('\n')
if _, err := io.WriteString(w.wc, builder.String()); err != nil {
fmt.Fprintf(os.Stderr, "!!! Failed to write message to log: %v\n", err)
}
}
func (w wcOutput) Close() error {
return w.wc.Close()
}
// WriteCloserOutput returns a log.Output implementation that
// will write formatted messages to the provided io.Writer.
//
// Closing returned log.Output object will close the underlying
// io.WriteCloser.
//
// Written messages will include timestamp formatted with millisecond
// precision and [debug] prefix for debug messages.
// If timestamps argument is false, timestamps will not be added.
//
// Returned log.Output does not provide its own serialization
// so goroutine-safety depends on the io.Writer. Most operating
// systems have atomic (read: thread-safe) implementations for
// stream I/O, so it should be safe to use WriterOutput with os.File.
func WriteCloserOutput(wc io.WriteCloser, timestamps bool) Output {
return wcOutput{timestamps, wc}
}
type nopCloser struct {
io.Writer
}
func (nc nopCloser) Close() error {
return nil
}
// WriterOutput returns a log.Output implementation that
// will write formatted messages to the provided io.Writer.
//
// Closing returned log.Output object will have no effect on the
// underlying io.Writer.
//
// Written messages will include timestamp formatted with millisecond
// precision and [debug] prefix for debug messages.
// If timestamps argument is false, timestamps will not be added.
//
// Returned log.Output does not provide its own serialization
// so goroutine-safety depends on the io.Writer. Most operating
// systems have atomic (read: thread-safe) implementations for
// stream I/O, so it should be safe to use WriterOutput with os.File.
func WriterOutput(w io.Writer, timestamps bool) Output {
return wcOutput{timestamps, nopCloser{os.Stderr}}
}