1package sideband
2
3import (
4	"io"
5
6	"github.com/go-git/go-git/v5/plumbing/format/pktline"
7)
8
9// Muxer multiplex the packfile along with the progress messages and the error
10// information. The multiplex is perform using pktline format.
11type Muxer struct {
12	max int
13	e   *pktline.Encoder
14}
15
16const chLen = 1
17
18// NewMuxer returns a new Muxer for the given t that writes on w.
19//
20// If t is equal to `Sideband` the max pack size is set to MaxPackedSize, in any
21// other value is given, max pack is set to MaxPackedSize64k, that is the
22// maximum length of a line in pktline format.
23func NewMuxer(t Type, w io.Writer) *Muxer {
24	max := MaxPackedSize64k
25	if t == Sideband {
26		max = MaxPackedSize
27	}
28
29	return &Muxer{
30		max: max - chLen,
31		e:   pktline.NewEncoder(w),
32	}
33}
34
35// Write writes p in the PackData channel
36func (m *Muxer) Write(p []byte) (int, error) {
37	return m.WriteChannel(PackData, p)
38}
39
40// WriteChannel writes p in the given channel. This method can be used with any
41// channel, but is recommend use it only for the ProgressMessage and
42// ErrorMessage channels and use Write for the PackData channel
43func (m *Muxer) WriteChannel(t Channel, p []byte) (int, error) {
44	wrote := 0
45	size := len(p)
46	for wrote < size {
47		n, err := m.doWrite(t, p[wrote:])
48		wrote += n
49
50		if err != nil {
51			return wrote, err
52		}
53	}
54
55	return wrote, nil
56}
57
58func (m *Muxer) doWrite(ch Channel, p []byte) (int, error) {
59	sz := len(p)
60	if sz > m.max {
61		sz = m.max
62	}
63
64	return sz, m.e.Encode(ch.WithPayload(p[:sz]))
65}
66