1package agent
2
3import (
4	"io"
5	"sync"
6)
7
8// GatedWriter is an io.Writer implementation that buffers all of its
9// data into an internal buffer until it is told to let data through.
10type GatedWriter struct {
11	Writer io.Writer
12
13	buf   [][]byte
14	flush bool
15	lock  sync.RWMutex
16}
17
18var _ io.Writer = &GatedWriter{}
19
20// Flush tells the GatedWriter to flush any buffered data and to stop
21// buffering.
22func (w *GatedWriter) Flush() {
23	w.lock.Lock()
24	w.flush = true
25	w.lock.Unlock()
26
27	for _, p := range w.buf {
28		w.Write(p)
29	}
30	w.buf = nil
31}
32
33func (w *GatedWriter) Write(p []byte) (n int, err error) {
34	w.lock.RLock()
35	defer w.lock.RUnlock()
36
37	if w.flush {
38		return w.Writer.Write(p)
39	}
40
41	p2 := make([]byte, len(p))
42	copy(p2, p)
43	w.buf = append(w.buf, p2)
44	return len(p), nil
45}
46