aboutsummaryrefslogtreecommitdiffstats
path: root/storage/filesystem/internal/dotgit/dotgit.go
blob: 75c98ff331248d18d94da5f47252526e12d371af (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
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
package dotgit

import (
	"errors"
	"os"
	"strings"

	"gopkg.in/src-d/go-git.v4/core"
	"gopkg.in/src-d/go-git.v4/utils/fs"
)

const (
	suffix         = ".git"
	packedRefsPath = "packed-refs"
	configPath     = "config"
)

var (
	// ErrNotFound is returned by New when the path is not found.
	ErrNotFound = errors.New("path not found")
	// ErrIdxNotFound is returned by Idxfile when the idx file is not found
	ErrIdxNotFound = errors.New("idx file not found")
	// ErrPackfileNotFound is returned by Packfile when the packfile is not found
	ErrPackfileNotFound = errors.New("packfile not found")
	// ErrObjfileNotFound is returned by Objectfile when the objectffile is not found
	ErrObjfileNotFound = errors.New("object file not found")
	// ErrConfigNotFound is returned by Config when the config is not found
	ErrConfigNotFound = errors.New("config file not found")
)

// The DotGit type represents a local git repository on disk. This
// type is not zero-value-safe, use the New function to initialize it.
type DotGit struct {
	fs   fs.FS
	path string
}

// New returns a DotGit value ready to be used. The path argument must
// be the absolute path of a git repository directory (e.g.
// "/foo/bar/.git").
func New(fs fs.FS, path string) (*DotGit, error) {
	d := &DotGit{fs: fs, path: path}
	if _, err := fs.Stat(path); err != nil {
		if os.IsNotExist(err) {
			return nil, ErrNotFound
		}
		return nil, err
	}

	return d, nil
}

// Refs scans the git directory collecting references, which it returns.
// Symbolic references are resolved and included in the output.
func (d *DotGit) Refs() ([]*core.Reference, error) {
	var refs []*core.Reference
	if err := d.addRefsFromPackedRefs(&refs); err != nil {
		return nil, err
	}

	if err := d.addRefsFromRefDir(&refs); err != nil {
		return nil, err
	}

	if err := d.addRefFromHEAD(&refs); err != nil {
		return nil, err
	}

	return refs, nil
}

// Packfile returns the path of the packfile (really, it returns the
// path of the first file in the "objects/pack/" directory with a
// ".pack" extension.
func (d *DotGit) Packfile() (fs.FS, string, error) {
	packDir := d.fs.Join(d.path, "objects", "pack")
	files, err := d.fs.ReadDir(packDir)
	if err != nil {
		if os.IsNotExist(err) {
			return nil, "", ErrPackfileNotFound
		}

		return nil, "", err
	}

	for _, f := range files {
		if strings.HasSuffix(f.Name(), ".pack") {
			return d.fs, d.fs.Join(packDir, f.Name()), nil
		}
	}

	return nil, "", ErrPackfileNotFound
}

// Idxfile returns the path of the idx file (really, it returns the
// path of the first file in the "objects/pack/" directory with an
// ".idx" extension.
func (d *DotGit) Idxfile() (fs.FS, string, error) {
	packDir := d.fs.Join(d.path, "objects", "pack")
	files, err := d.fs.ReadDir(packDir)
	if err != nil {
		if os.IsNotExist(err) {
			return nil, "", ErrIdxNotFound
		}

		return nil, "", err
	}

	for _, f := range files {
		if strings.HasSuffix(f.Name(), ".idx") {
			return d.fs, d.fs.Join(packDir, f.Name()), nil
		}
	}

	return nil, "", ErrIdxNotFound
}

// Config returns the path of the config file
func (d *DotGit) Config() (fs.FS, string, error) {
	configFile := d.fs.Join(d.path, configPath)
	if _, err := d.fs.Stat(configFile); err != nil {
		if os.IsNotExist(err) {
			return nil, "", ErrNotFound
		}

		return nil, "", err
	}

	return d.fs, configFile, nil
}

// Objectfiles returns a slice with the hashes of objects found under the
// .git/objects/ directory.
func (dg *DotGit) Objectfiles() (fs.FS, []core.Hash, error) {
	objsDir := dg.fs.Join(dg.path, "objects")

	files, err := dg.fs.ReadDir(objsDir)
	if err != nil {
		if os.IsNotExist(err) {
			return nil, nil, ErrObjfileNotFound
		}

		return nil, nil, err
	}

	var objects []core.Hash
	for _, f := range files {
		if f.IsDir() && len(f.Name()) == 2 && isHex(f.Name()) {
			objDir := f.Name()
			d, err := dg.fs.ReadDir(dg.fs.Join(objsDir, objDir))
			if err != nil {
				return nil, nil, err
			}

			for _, o := range d {
				objects = append(objects, core.NewHash(objDir+o.Name()))
			}
		}
	}

	return dg.fs, objects, nil
}

func isHex(s string) bool {
	for _, b := range []byte(s) {
		if isNum(b) {
			continue
		}
		if isHexAlpha(b) {
			continue
		}

		return false
	}

	return true
}

func isNum(b byte) bool {
	return b >= '0' && b <= '9'
}

func isHexAlpha(b byte) bool {
	return b >= 'a' && b <= 'f' || b >= 'A' && b <= 'F'
}

// Objectfile returns the path of the object file for a given hash
// *if the file exists*, otherwise returns an ErrObjfileNotFound error.
func (d *DotGit) Objectfile(h core.Hash) (fs.FS, string, error) {
	hash := h.String()
	objFile := d.fs.Join(d.path, "objects", hash[0:2], hash[2:40])

	if _, err := d.fs.Stat(objFile); err != nil {
		if os.IsNotExist(err) {
			return nil, "", ErrObjfileNotFound
		}

		return nil, "", err
	}

	return d.fs, objFile, nil
}