aboutsummaryrefslogtreecommitdiffstats
path: root/plumbing/protocol/packp/ulreq_encode.go
blob: 8b19c0f674144c5502bb419147b1f9f2ca856e70 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
package packp

import (
	"bytes"
	"fmt"
	"io"
	"time"

	"github.com/go-git/go-git/v5/plumbing"
	"github.com/go-git/go-git/v5/plumbing/format/pktline"
)

// Encode writes the UlReq encoding of u to the stream.
//
// All the payloads will end with a newline character.  Wants and
// shallows are sorted alphabetically.  A depth of 0 means no depth
// request is sent.
func (req *UploadRequest) Encode(w io.Writer) error {
	e := newUlReqEncoder(w)
	return e.Encode(req)
}

type ulReqEncoder struct {
	pe   *pktline.Encoder // where to write the encoded data
	data *UploadRequest   // the data to encode
	err  error            // sticky error
}

func newUlReqEncoder(w io.Writer) *ulReqEncoder {
	return &ulReqEncoder{
		pe: pktline.NewEncoder(w),
	}
}

func (e *ulReqEncoder) Encode(v *UploadRequest) error {
	e.data = v

	if len(v.Wants) == 0 {
		return fmt.Errorf("empty wants provided")
	}

	plumbing.HashesSort(e.data.Wants)
	for state := e.encodeFirstWant; state != nil; {
		state = state()
	}

	return e.err
}

func (e *ulReqEncoder) encodeFirstWant() stateFn {
	var err error
	if e.data.Capabilities.IsEmpty() {
		err = e.pe.Encodef("want %s\n", e.data.Wants[0])
	} else {
		err = e.pe.Encodef(
			"want %s %s\n",
			e.data.Wants[0],
			e.data.Capabilities.String(),
		)
	}

	if err != nil {
		e.err = fmt.Errorf("encoding first want line: %s", err)
		return nil
	}

	return e.encodeAdditionalWants
}

func (e *ulReqEncoder) encodeAdditionalWants() stateFn {
	last := e.data.Wants[0]
	for _, w := range e.data.Wants[1:] {
		if bytes.Equal(last[:], w[:]) {
			continue
		}

		if err := e.pe.Encodef("want %s\n", w); err != nil {
			e.err = fmt.Errorf("encoding want %q: %s", w, err)
			return nil
		}

		last = w
	}

	return e.encodeShallows
}

func (e *ulReqEncoder) encodeShallows() stateFn {
	plumbing.HashesSort(e.data.Shallows)

	var last plumbing.Hash
	for _, s := range e.data.Shallows {
		if bytes.Equal(last[:], s[:]) {
			continue
		}

		if err := e.pe.Encodef("shallow %s\n", s); err != nil {
			e.err = fmt.Errorf("encoding shallow %q: %s", s, err)
			return nil
		}

		last = s
	}

	return e.encodeDepth
}

func (e *ulReqEncoder) encodeDepth() stateFn {
	switch depth := e.data.Depth.(type) {
	case DepthCommits:
		if depth != 0 {
			commits := int(depth)
			if err := e.pe.Encodef("deepen %d\n", commits); err != nil {
				e.err = fmt.Errorf("encoding depth %d: %s", depth, err)
				return nil
			}
		}
	case DepthSince:
		when := time.Time(depth).UTC()
		if err := e.pe.Encodef("deepen-since %d\n", when.Unix()); err != nil {
			e.err = fmt.Errorf("encoding depth %s: %s", when, err)
			return nil
		}
	case DepthReference:
		reference := string(depth)
		if err := e.pe.Encodef("deepen-not %s\n", reference); err != nil {
			e.err = fmt.Errorf("encoding depth %s: %s", reference, err)
			return nil
		}
	default:
		e.err = fmt.Errorf("unsupported depth type")
		return nil
	}

	return e.encodeFilter
}

func (e *ulReqEncoder) encodeFilter() stateFn {
	if filter := e.data.Filter; filter != "" {
		if err := e.pe.Encodef("filter %s\n", filter); err != nil {
			e.err = fmt.Errorf("encoding filter %s: %s", filter, err)
			return nil
		}
	}

	return e.encodeFlush
}

func (e *ulReqEncoder) encodeFlush() stateFn {
	if err := e.pe.Flush(); err != nil {
		e.err = fmt.Errorf("encoding flush-pkt: %s", err)
		return nil
	}

	return nil
}