kot.pink
1package git
2
3import (
4 "archive/tar"
5 "bytes"
6 "fmt"
7 "io"
8 "io/fs"
9 "os/exec"
10 "path"
11 "sort"
12 "strings"
13 "sync"
14 "time"
15
16 "github.com/dgraph-io/ristretto"
17 "github.com/go-git/go-git/v5"
18 "github.com/go-git/go-git/v5/plumbing"
19 "github.com/go-git/go-git/v5/plumbing/object"
20)
21
22var (
23 commitCache *ristretto.Cache
24 cacheMu sync.RWMutex
25)
26
27func init() {
28 cache, _ := ristretto.NewCache(&ristretto.Config{
29 NumCounters: 1e7,
30 MaxCost: 1 << 30,
31 BufferItems: 64,
32 })
33 commitCache = cache
34}
35
36var (
37 ErrBinaryFile = fmt.Errorf("binary file")
38)
39
40type GitRepo struct {
41 path string
42 r *git.Repository
43 h plumbing.Hash
44}
45
46type TagList struct {
47 refs []*TagReference
48 r *git.Repository
49}
50
51// TagReference is used to list both tag and non-annotated tags.
52// Non-annotated tags should only contains a reference.
53// Annotated tags should contain its reference and its tag information.
54type TagReference struct {
55 ref *plumbing.Reference
56 tag *object.Tag
57}
58
59// infoWrapper wraps the property of a TreeEntry so it can export fs.FileInfo
60// to tar WriteHeader
61type infoWrapper struct {
62 name string
63 size int64
64 mode fs.FileMode
65 modTime time.Time
66 isDir bool
67}
68
69func (self *TagList) Len() int {
70 return len(self.refs)
71}
72
73func (self *TagList) Swap(i, j int) {
74 self.refs[i], self.refs[j] = self.refs[j], self.refs[i]
75}
76
77// sorting tags in reverse chronological order
78func (self *TagList) Less(i, j int) bool {
79 var dateI time.Time
80 var dateJ time.Time
81
82 if self.refs[i].tag != nil {
83 dateI = self.refs[i].tag.Tagger.When
84 } else {
85 c, err := self.r.CommitObject(self.refs[i].ref.Hash())
86 if err != nil {
87 dateI = time.Now()
88 } else {
89 dateI = c.Committer.When
90 }
91 }
92
93 if self.refs[j].tag != nil {
94 dateJ = self.refs[j].tag.Tagger.When
95 } else {
96 c, err := self.r.CommitObject(self.refs[j].ref.Hash())
97 if err != nil {
98 dateJ = time.Now()
99 } else {
100 dateJ = c.Committer.When
101 }
102 }
103
104 return dateI.After(dateJ)
105}
106
107func Open(path string, ref string) (*GitRepo, error) {
108 var err error
109 g := GitRepo{path: path}
110 g.r, err = git.PlainOpen(path)
111 if err != nil {
112 return nil, fmt.Errorf("opening %s: %w", path, err)
113 }
114
115 if ref == "" {
116 head, err := g.r.Head()
117 if err != nil {
118 return nil, fmt.Errorf("getting head of %s: %w", path, err)
119 }
120 g.h = head.Hash()
121 } else {
122 hash, err := g.r.ResolveRevision(plumbing.Revision(ref))
123 if err != nil {
124 return nil, fmt.Errorf("resolving rev %s for %s: %w", ref, path, err)
125 }
126 g.h = *hash
127 }
128 return &g, nil
129}
130
131func (g *GitRepo) Commits() ([]*object.Commit, error) {
132 ci, err := g.r.Log(&git.LogOptions{From: g.h})
133 if err != nil {
134 return nil, fmt.Errorf("commits from ref: %w", err)
135 }
136
137 commits := []*object.Commit{}
138 ci.ForEach(func(c *object.Commit) error {
139 commits = append(commits, c)
140 return nil
141 })
142
143 return commits, nil
144}
145
146func (g *GitRepo) LastCommit() (*object.Commit, error) {
147 c, err := g.r.CommitObject(g.h)
148 if err != nil {
149 return nil, fmt.Errorf("last commit: %w", err)
150 }
151 return c, nil
152}
153
154func (g *GitRepo) FileContent(path string) (string, error) {
155 c, err := g.r.CommitObject(g.h)
156 if err != nil {
157 return "", fmt.Errorf("commit object: %w", err)
158 }
159
160 tree, err := c.Tree()
161 if err != nil {
162 return "", fmt.Errorf("file tree: %w", err)
163 }
164
165 file, err := tree.File(path)
166 if err != nil {
167 return "", err
168 }
169
170 isbin, _ := file.IsBinary()
171
172 if !isbin {
173 return file.Contents()
174 } else {
175 return "", ErrBinaryFile
176 }
177}
178
179func (g *GitRepo) Tags() ([]*TagReference, error) {
180 iter, err := g.r.Tags()
181 if err != nil {
182 return nil, fmt.Errorf("tag objects: %w", err)
183 }
184
185 tags := make([]*TagReference, 0)
186
187 if err := iter.ForEach(func(ref *plumbing.Reference) error {
188 obj, err := g.r.TagObject(ref.Hash())
189 switch err {
190 case nil:
191 tags = append(tags, &TagReference{
192 ref: ref,
193 tag: obj,
194 })
195 case plumbing.ErrObjectNotFound:
196 tags = append(tags, &TagReference{
197 ref: ref,
198 })
199 default:
200 return err
201 }
202 return nil
203 }); err != nil {
204 return nil, err
205 }
206
207 tagList := &TagList{r: g.r, refs: tags}
208 sort.Sort(tagList)
209 return tags, nil
210}
211
212func (g *GitRepo) Branches() ([]*plumbing.Reference, error) {
213 bi, err := g.r.Branches()
214 if err != nil {
215 return nil, fmt.Errorf("branchs: %w", err)
216 }
217
218 branches := []*plumbing.Reference{}
219
220 _ = bi.ForEach(func(ref *plumbing.Reference) error {
221 branches = append(branches, ref)
222 return nil
223 })
224
225 return branches, nil
226}
227
228func (g *GitRepo) FindMainBranch(branches []string) (string, error) {
229 branches = append(branches, []string{
230 "main",
231 "master",
232 "trunk",
233 }...)
234 for _, b := range branches {
235 _, err := g.r.ResolveRevision(plumbing.Revision(b))
236 if err == nil {
237 return b, nil
238 }
239 }
240 return "", fmt.Errorf("unable to find main branch")
241}
242
243// WriteTar writes itself from a tree into a binary tar file format.
244// prefix is root folder to be appended.
245func (g *GitRepo) WriteTar(w io.Writer, prefix string) error {
246 tw := tar.NewWriter(w)
247 defer tw.Close()
248
249 c, err := g.r.CommitObject(g.h)
250 if err != nil {
251 return fmt.Errorf("commit object: %w", err)
252 }
253
254 tree, err := c.Tree()
255 if err != nil {
256 return err
257 }
258
259 walker := object.NewTreeWalker(tree, true, nil)
260 defer walker.Close()
261
262 name, entry, err := walker.Next()
263 for ; err == nil; name, entry, err = walker.Next() {
264 info, err := newInfoWrapper(name, prefix, &entry, tree)
265 if err != nil {
266 return err
267 }
268
269 header, err := tar.FileInfoHeader(info, "")
270 if err != nil {
271 return err
272 }
273
274 err = tw.WriteHeader(header)
275 if err != nil {
276 return err
277 }
278
279 if !info.IsDir() {
280 file, err := tree.File(name)
281 if err != nil {
282 return err
283 }
284
285 reader, err := file.Blob.Reader()
286 if err != nil {
287 return err
288 }
289
290 _, err = io.Copy(tw, reader)
291 if err != nil {
292 reader.Close()
293 return err
294 }
295 reader.Close()
296 }
297 }
298
299 return nil
300}
301
302func (g *GitRepo) LastCommitForPath(path string) (*object.Commit, error) {
303 cacheMu.RLock()
304 if commit, found := commitCache.Get(path); found {
305 cacheMu.RUnlock()
306 return commit.(*object.Commit), nil
307 }
308 cacheMu.RUnlock()
309
310 cmd := exec.Command("git", "-C", g.path, "log", "-1", "--format=%H", "--", path)
311
312 var out bytes.Buffer
313 cmd.Stdout = &out
314 cmd.Stderr = &out
315
316 if err := cmd.Run(); err != nil {
317 return nil, fmt.Errorf("failed to get commit hash: %w", err)
318 }
319
320 commitHash := strings.TrimSpace(out.String())
321 if commitHash == "" {
322 return nil, fmt.Errorf("no commits found for path: %s", path)
323 }
324
325 hash := plumbing.NewHash(commitHash)
326
327 commit, err := g.r.CommitObject(hash)
328 if err != nil {
329 return nil, err
330 }
331
332 cacheMu.Lock()
333 commitCache.Set(path, commit, 1)
334 cacheMu.Unlock()
335
336 return commit, nil
337}
338
339func newInfoWrapper(
340 name string,
341 prefix string,
342 entry *object.TreeEntry,
343 tree *object.Tree,
344) (*infoWrapper, error) {
345 var (
346 size int64
347 mode fs.FileMode
348 isDir bool
349 )
350
351 if entry.Mode.IsFile() {
352 file, err := tree.TreeEntryFile(entry)
353 if err != nil {
354 return nil, err
355 }
356 mode = fs.FileMode(file.Mode)
357
358 size, err = tree.Size(name)
359 if err != nil {
360 return nil, err
361 }
362 } else {
363 isDir = true
364 mode = fs.ModeDir | fs.ModePerm
365 }
366
367 fullname := path.Join(prefix, name)
368 return &infoWrapper{
369 name: fullname,
370 size: size,
371 mode: mode,
372 modTime: time.Unix(0, 0),
373 isDir: isDir,
374 }, nil
375}
376
377func (i *infoWrapper) Name() string {
378 return i.name
379}
380
381func (i *infoWrapper) Size() int64 {
382 return i.size
383}
384
385func (i *infoWrapper) Mode() fs.FileMode {
386 return i.mode
387}
388
389func (i *infoWrapper) ModTime() time.Time {
390 return i.modTime
391}
392
393func (i *infoWrapper) IsDir() bool {
394 return i.isDir
395}
396
397func (i *infoWrapper) Sys() any {
398 return nil
399}
400
401func (t *TagReference) Name() string {
402 return t.ref.Name().Short()
403}
404
405func (t *TagReference) Message() string {
406 if t.tag != nil {
407 return t.tag.Message
408 }
409 return ""
410}
411
412func (t *TagReference) TagObject() *object.Tag {
413 return t.tag
414}
415
416func (t *TagReference) Hash() plumbing.Hash {
417 return t.ref.Hash()
418}