open-vault/helper/gated-writer/writer.go

44 lines
717 B
Go

package gatedwriter
import (
"io"
"sync"
)
// Writer is an io.Writer implementation that buffers all of its
// data into an internal buffer until it is told to let data through.
type Writer struct {
Writer io.Writer
buf [][]byte
flush bool
lock sync.RWMutex
}
// Flush tells the Writer to flush any buffered data and to stop
// buffering.
func (w *Writer) Flush() {
w.lock.Lock()
w.flush = true
w.lock.Unlock()
for _, p := range w.buf {
w.Write(p)
}
w.buf = nil
}
func (w *Writer) Write(p []byte) (n int, err error) {
w.lock.RLock()
defer w.lock.RUnlock()
if w.flush {
return w.Writer.Write(p)
}
p2 := make([]byte, len(p))
copy(p2, p)
w.buf = append(w.buf, p2)
return len(p), nil
}