58 lines
1.1 KiB
Go
58 lines
1.1 KiB
Go
|
package main
|
||
|
|
|
||
|
|
import (
|
||
|
|
"io"
|
||
|
|
"errors"
|
||
|
|
"time"
|
||
|
|
)
|
||
|
|
|
||
|
|
const MAX_LOG_QLEN = 128
|
||
|
|
const QUEUE_SHUTDOWN_TIMEOUT = 500 * time.Millisecond
|
||
|
|
|
||
|
|
type LogWriter struct {
|
||
|
|
writer io.Writer
|
||
|
|
ch chan []byte
|
||
|
|
done chan struct{}
|
||
|
|
}
|
||
|
|
|
||
|
|
func (lw *LogWriter) Write(p []byte) (int, error) {
|
||
|
|
if p == nil {
|
||
|
|
return 0, errors.New("Can't write nil byte slice")
|
||
|
|
}
|
||
|
|
buf := make([]byte, len(p))
|
||
|
|
copy(buf, p)
|
||
|
|
select {
|
||
|
|
case lw.ch <- buf:
|
||
|
|
return len(p), nil
|
||
|
|
default:
|
||
|
|
return 0, errors.New("Writer queue overflow")
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
func NewLogWriter(writer io.Writer) *LogWriter {
|
||
|
|
lw := &LogWriter{writer,
|
||
|
|
make(chan []byte, MAX_LOG_QLEN),
|
||
|
|
make(chan struct{})}
|
||
|
|
go lw.loop()
|
||
|
|
return lw
|
||
|
|
}
|
||
|
|
|
||
|
|
func (lw *LogWriter) loop() {
|
||
|
|
for p := range lw.ch {
|
||
|
|
if p == nil {
|
||
|
|
break
|
||
|
|
}
|
||
|
|
lw.writer.Write(p)
|
||
|
|
}
|
||
|
|
lw.done <- struct{}{}
|
||
|
|
}
|
||
|
|
|
||
|
|
func (lw *LogWriter) Close() {
|
||
|
|
lw.ch <- nil
|
||
|
|
timer := time.After(QUEUE_SHUTDOWN_TIMEOUT)
|
||
|
|
select {
|
||
|
|
case <-timer:
|
||
|
|
case <-lw.done:
|
||
|
|
}
|
||
|
|
}
|