aboutsummaryrefslogtreecommitdiffstats
path: root/plumbing/transport/fetch_pack.go
blob: 14d3e1908f0c31ff06a14b9cc63ee2e806d3b17d (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
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
package transport

import (
	"bytes"
	"fmt"
	"io"
	"io/ioutil"
	"strings"

	"gopkg.in/src-d/go-git.v4/plumbing"
	"gopkg.in/src-d/go-git.v4/plumbing/format/pktline"
	"gopkg.in/src-d/go-git.v4/plumbing/protocol/packp"
	"gopkg.in/src-d/go-git.v4/plumbing/storer"
	"gopkg.in/src-d/go-git.v4/storage/memory"
)

//TODO: Replace this by packpAdvRefs.
type UploadPackInfo struct {
	Capabilities *packp.Capabilities
	Refs         memory.ReferenceStorage
}

func NewUploadPackInfo() *UploadPackInfo {
	return &UploadPackInfo{
		Capabilities: packp.NewCapabilities(),
		Refs:         make(memory.ReferenceStorage, 0),
	}
}

func (i *UploadPackInfo) Decode(r io.Reader) error {
	d := packp.NewAdvRefsDecoder(r)
	ar := packp.NewAdvRefs()
	if err := d.Decode(ar); err != nil {
		if err == packp.ErrEmpty {
			return err
		}
		return plumbing.NewUnexpectedError(err)
	}

	i.Capabilities = ar.Capabilities

	if err := i.addRefs(ar); err != nil {
		return plumbing.NewUnexpectedError(err)
	}

	return nil
}

func (i *UploadPackInfo) addRefs(ar *packp.AdvRefs) error {
	for name, hash := range ar.References {
		ref := plumbing.NewReferenceFromStrings(name, hash.String())
		i.Refs.SetReference(ref)
	}

	return i.addSymbolicRefs(ar)
}

func (i *UploadPackInfo) addSymbolicRefs(ar *packp.AdvRefs) error {
	if !hasSymrefs(ar) {
		return nil
	}

	for _, symref := range ar.Capabilities.Get("symref").Values {
		chunks := strings.Split(symref, ":")
		if len(chunks) != 2 {
			err := fmt.Errorf("bad number of `:` in symref value (%q)", symref)
			return plumbing.NewUnexpectedError(err)
		}
		name := plumbing.ReferenceName(chunks[0])
		target := plumbing.ReferenceName(chunks[1])
		ref := plumbing.NewSymbolicReference(name, target)
		i.Refs.SetReference(ref)
	}

	return nil
}

func hasSymrefs(ar *packp.AdvRefs) bool {
	return ar.Capabilities.Supports("symref")
}

func (i *UploadPackInfo) Head() *plumbing.Reference {
	ref, _ := storer.ResolveReference(i.Refs, plumbing.HEAD)
	return ref
}

func (i *UploadPackInfo) String() string {
	return string(i.Bytes())
}

func (i *UploadPackInfo) Bytes() []byte {
	var buf bytes.Buffer
	e := pktline.NewEncoder(&buf)

	_ = e.EncodeString("# service=git-upload-pack\n")

	// inserting a flush-pkt here violates the protocol spec, but some
	// servers do it, like Github.com
	e.Flush()

	_ = e.Encodef("%s HEAD\x00%s\n", i.Head().Hash(), i.Capabilities.String())

	for _, ref := range i.Refs {
		if ref.Type() != plumbing.HashReference {
			continue
		}

		_ = e.Encodef("%s %s\n", ref.Hash(), ref.Name())
	}

	e.Flush()

	return buf.Bytes()
}

type UploadPackRequest struct {
	Wants []plumbing.Hash
	Haves []plumbing.Hash
	Depth int
}

func (r *UploadPackRequest) Want(h ...plumbing.Hash) {
	r.Wants = append(r.Wants, h...)
}

func (r *UploadPackRequest) Have(h ...plumbing.Hash) {
	r.Haves = append(r.Haves, h...)
}

func (r *UploadPackRequest) IsEmpty() bool {
	return isSubset(r.Wants, r.Haves)
}

func isSubset(needle []plumbing.Hash, haystack []plumbing.Hash) bool {
	for _, h := range needle {
		found := false
		for _, oh := range haystack {
			if h == oh {
				found = true
				break
			}
		}

		if !found {
			return false
		}
	}

	return true
}

func (r *UploadPackRequest) String() string {
	b, _ := ioutil.ReadAll(r.Reader())
	return string(b)
}

func (r *UploadPackRequest) Reader() *strings.Reader {
	var buf bytes.Buffer
	e := pktline.NewEncoder(&buf)

	for _, want := range r.Wants {
		_ = e.Encodef("want %s\n", want)
	}

	for _, have := range r.Haves {
		_ = e.Encodef("have %s\n", have)
	}

	if r.Depth != 0 {
		_ = e.Encodef("deepen %d\n", r.Depth)
	}

	_ = e.Flush()
	_ = e.EncodeString("done\n")

	return strings.NewReader(buf.String())
}