av/codec/codecutil/lex.go

63 lines
1.4 KiB
Go

/*
NAME
lex.go
AUTHOR
Trek Hopton <trek@ausocean.org>
LICENSE
This file is Copyright (C) 2019 the Australian Ocean Lab (AusOcean)
It is free software: you can redistribute it and/or modify them
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.
It 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 in gpl.txt.
If not, see [GNU licenses](http://www.gnu.org/licenses).
*/
package codecutil
import (
"fmt"
"io"
"time"
)
// LexBytes reads n bytes from src and writes them to dst every t seconds.
func LexBytes(dst io.Writer, src io.Reader, t time.Duration, n int) error {
if n <= 0 {
return fmt.Errorf("invalid buffer size: %v", n)
}
if t < 0 {
return fmt.Errorf("invalid delay: %v", t)
}
var tick <-chan time.Time
if t > 0 {
ticker := time.NewTicker(t)
defer ticker.Stop()
tick = ticker.C
}
buf := make([]byte, n)
for {
if t != 0 {
<-tick
}
off, err := src.Read(buf)
if err != nil {
return err
}
_, err = dst.Write(buf[:off])
if err != nil {
return err
}
}
}