nel.pet
1package git
2
3import (
4 "archive/tar"
5 "bytes"
6 "fmt"
7 "io"
8 "io/fs"
9 "os/exec"
10 "path"
11 "sort"
12 "strconv"
13 "strings"
14 "sync"
15 "time"
16
17 "github.com/dgraph-io/ristretto"
18 "github.com/go-git/go-git/v5"
19 "github.com/go-git/go-git/v5/plumbing"
20 "github.com/go-git/go-git/v5/plumbing/object"
21 "tangled.sh/tangled.sh/core/types"
22)
23
24var (
25 commitCache *ristretto.Cache
26 cacheMu sync.RWMutex
27)
28
29func init() {
30 cache, _ := ristretto.NewCache(&ristretto.Config{
31 NumCounters: 1e7,
32 MaxCost: 1 << 30,
33 BufferItems: 64,
34 TtlTickerDurationInSec: 120,
35 })
36 commitCache = cache
37}
38
39var (
40 ErrBinaryFile = fmt.Errorf("binary file")
41 ErrNotBinaryFile = fmt.Errorf("not binary file")
42)
43
44type GitRepo struct {
45 path string
46 r *git.Repository
47 h plumbing.Hash
48}
49
50type TagList struct {
51 refs []*TagReference
52 r *git.Repository
53}
54
55// TagReference is used to list both tag and non-annotated tags.
56// Non-annotated tags should only contains a reference.
57// Annotated tags should contain its reference and its tag information.
58type TagReference struct {
59 ref *plumbing.Reference
60 tag *object.Tag
61}
62
63// infoWrapper wraps the property of a TreeEntry so it can export fs.FileInfo
64// to tar WriteHeader
65type infoWrapper struct {
66 name string
67 size int64
68 mode fs.FileMode
69 modTime time.Time
70 isDir bool
71}
72
73func (self *TagList) Len() int {
74 return len(self.refs)
75}
76
77func (self *TagList) Swap(i, j int) {
78 self.refs[i], self.refs[j] = self.refs[j], self.refs[i]
79}
80
81// sorting tags in reverse chronological order
82func (self *TagList) Less(i, j int) bool {
83 var dateI time.Time
84 var dateJ time.Time
85
86 if self.refs[i].tag != nil {
87 dateI = self.refs[i].tag.Tagger.When
88 } else {
89 c, err := self.r.CommitObject(self.refs[i].ref.Hash())
90 if err != nil {
91 dateI = time.Now()
92 } else {
93 dateI = c.Committer.When
94 }
95 }
96
97 if self.refs[j].tag != nil {
98 dateJ = self.refs[j].tag.Tagger.When
99 } else {
100 c, err := self.r.CommitObject(self.refs[j].ref.Hash())
101 if err != nil {
102 dateJ = time.Now()
103 } else {
104 dateJ = c.Committer.When
105 }
106 }
107
108 return dateI.After(dateJ)
109}
110
111func Open(path string, ref string) (*GitRepo, error) {
112 var err error
113 g := GitRepo{path: path}
114 g.r, err = git.PlainOpen(path)
115 if err != nil {
116 return nil, fmt.Errorf("opening %s: %w", path, err)
117 }
118
119 if ref == "" {
120 head, err := g.r.Head()
121 if err != nil {
122 return nil, fmt.Errorf("getting head of %s: %w", path, err)
123 }
124 g.h = head.Hash()
125 } else {
126 hash, err := g.r.ResolveRevision(plumbing.Revision(ref))
127 if err != nil {
128 return nil, fmt.Errorf("resolving rev %s for %s: %w", ref, path, err)
129 }
130 g.h = *hash
131 }
132 return &g, nil
133}
134
135func PlainOpen(path string) (*GitRepo, error) {
136 var err error
137 g := GitRepo{path: path}
138 g.r, err = git.PlainOpen(path)
139 if err != nil {
140 return nil, fmt.Errorf("opening %s: %w", path, err)
141 }
142 return &g, nil
143}
144
145func (g *GitRepo) Commits() ([]*object.Commit, error) {
146 ci, err := g.r.Log(&git.LogOptions{From: g.h})
147 if err != nil {
148 return nil, fmt.Errorf("commits from ref: %w", err)
149 }
150
151 commits := []*object.Commit{}
152 ci.ForEach(func(c *object.Commit) error {
153 commits = append(commits, c)
154 return nil
155 })
156
157 return commits, nil
158}
159
160func (g *GitRepo) Commit(h plumbing.Hash) (*object.Commit, error) {
161 return g.r.CommitObject(h)
162}
163
164func (g *GitRepo) LastCommit() (*object.Commit, error) {
165 c, err := g.r.CommitObject(g.h)
166 if err != nil {
167 return nil, fmt.Errorf("last commit: %w", err)
168 }
169 return c, nil
170}
171
172func (g *GitRepo) FileContent(path string) (string, error) {
173 c, err := g.r.CommitObject(g.h)
174 if err != nil {
175 return "", fmt.Errorf("commit object: %w", err)
176 }
177
178 tree, err := c.Tree()
179 if err != nil {
180 return "", fmt.Errorf("file tree: %w", err)
181 }
182
183 file, err := tree.File(path)
184 if err != nil {
185 return "", err
186 }
187
188 isbin, _ := file.IsBinary()
189
190 if !isbin {
191 return file.Contents()
192 } else {
193 return "", ErrBinaryFile
194 }
195}
196
197func (g *GitRepo) RawContent(path string) ([]byte, error) {
198 c, err := g.r.CommitObject(g.h)
199 if err != nil {
200 return nil, fmt.Errorf("commit object: %w", err)
201 }
202
203 tree, err := c.Tree()
204 if err != nil {
205 return nil, fmt.Errorf("file tree: %w", err)
206 }
207
208 file, err := tree.File(path)
209 if err != nil {
210 return nil, err
211 }
212
213 reader, err := file.Reader()
214 if err != nil {
215 return nil, fmt.Errorf("opening file reader: %w", err)
216 }
217 defer reader.Close()
218
219 return io.ReadAll(reader)
220}
221
222func (g *GitRepo) Tags() ([]*TagReference, error) {
223 iter, err := g.r.Tags()
224 if err != nil {
225 return nil, fmt.Errorf("tag objects: %w", err)
226 }
227
228 tags := make([]*TagReference, 0)
229
230 if err := iter.ForEach(func(ref *plumbing.Reference) error {
231 obj, err := g.r.TagObject(ref.Hash())
232 switch err {
233 case nil:
234 tags = append(tags, &TagReference{
235 ref: ref,
236 tag: obj,
237 })
238 case plumbing.ErrObjectNotFound:
239 tags = append(tags, &TagReference{
240 ref: ref,
241 })
242 default:
243 return err
244 }
245 return nil
246 }); err != nil {
247 return nil, err
248 }
249
250 tagList := &TagList{r: g.r, refs: tags}
251 sort.Sort(tagList)
252 return tags, nil
253}
254
255func (g *GitRepo) Branches() ([]types.Branch, error) {
256 bi, err := g.r.Branches()
257 if err != nil {
258 return nil, fmt.Errorf("branchs: %w", err)
259 }
260
261 branches := []types.Branch{}
262
263 defaultBranch, err := g.FindMainBranch()
264
265 _ = bi.ForEach(func(ref *plumbing.Reference) error {
266 b := types.Branch{}
267 b.Hash = ref.Hash().String()
268 b.Name = ref.Name().Short()
269
270 // resolve commit that this branch points to
271 commit, _ := g.Commit(ref.Hash())
272 if commit != nil {
273 b.Commit = commit
274 }
275
276 if defaultBranch != "" && defaultBranch == b.Name {
277 b.IsDefault = true
278 }
279
280 branches = append(branches, b)
281
282 return nil
283 })
284
285 return branches, nil
286}
287
288func (g *GitRepo) Branch(name string) (*plumbing.Reference, error) {
289 ref, err := g.r.Reference(plumbing.NewBranchReferenceName(name), false)
290 if err != nil {
291 return nil, fmt.Errorf("branch: %w", err)
292 }
293
294 if !ref.Name().IsBranch() {
295 return nil, fmt.Errorf("branch: %s is not a branch", ref.Name())
296 }
297
298 return ref, nil
299}
300
301func (g *GitRepo) SetDefaultBranch(branch string) error {
302 ref := plumbing.NewSymbolicReference(plumbing.HEAD, plumbing.NewBranchReferenceName(branch))
303 return g.r.Storer.SetReference(ref)
304}
305
306func (g *GitRepo) FindMainBranch() (string, error) {
307 ref, err := g.r.Head()
308 if err != nil {
309 return "", fmt.Errorf("unable to find main branch: %w", err)
310 }
311 if ref.Name().IsBranch() {
312 return strings.TrimPrefix(string(ref.Name()), "refs/heads/"), nil
313 }
314
315 return "", fmt.Errorf("unable to find main branch: %w", err)
316}
317
318// WriteTar writes itself from a tree into a binary tar file format.
319// prefix is root folder to be appended.
320func (g *GitRepo) WriteTar(w io.Writer, prefix string) error {
321 tw := tar.NewWriter(w)
322 defer tw.Close()
323
324 c, err := g.r.CommitObject(g.h)
325 if err != nil {
326 return fmt.Errorf("commit object: %w", err)
327 }
328
329 tree, err := c.Tree()
330 if err != nil {
331 return err
332 }
333
334 walker := object.NewTreeWalker(tree, true, nil)
335 defer walker.Close()
336
337 name, entry, err := walker.Next()
338 for ; err == nil; name, entry, err = walker.Next() {
339 info, err := newInfoWrapper(name, prefix, &entry, tree)
340 if err != nil {
341 return err
342 }
343
344 header, err := tar.FileInfoHeader(info, "")
345 if err != nil {
346 return err
347 }
348
349 err = tw.WriteHeader(header)
350 if err != nil {
351 return err
352 }
353
354 if !info.IsDir() {
355 file, err := tree.File(name)
356 if err != nil {
357 return err
358 }
359
360 reader, err := file.Blob.Reader()
361 if err != nil {
362 return err
363 }
364
365 _, err = io.Copy(tw, reader)
366 if err != nil {
367 reader.Close()
368 return err
369 }
370 reader.Close()
371 }
372 }
373
374 return nil
375}
376
377func (g *GitRepo) LastCommitForPath(path string) (*types.LastCommitInfo, error) {
378 cacheKey := fmt.Sprintf("%s:%s", g.h.String(), path)
379 cacheMu.RLock()
380 if commitInfo, found := commitCache.Get(cacheKey); found {
381 cacheMu.RUnlock()
382 return commitInfo.(*types.LastCommitInfo), nil
383 }
384 cacheMu.RUnlock()
385
386 cmd := exec.Command("git", "-C", g.path, "log", g.h.String(), "-1", "--format=%H %ct", "--", path)
387
388 var out bytes.Buffer
389 cmd.Stdout = &out
390 cmd.Stderr = &out
391
392 if err := cmd.Run(); err != nil {
393 return nil, fmt.Errorf("failed to get commit hash: %w", err)
394 }
395
396 output := strings.TrimSpace(out.String())
397 if output == "" {
398 return nil, fmt.Errorf("no commits found for path: %s", path)
399 }
400
401 parts := strings.SplitN(output, " ", 2)
402 if len(parts) < 2 {
403 return nil, fmt.Errorf("unexpected commit log format")
404 }
405
406 commitHash := parts[0]
407 commitTimeUnix, err := strconv.ParseInt(parts[1], 10, 64)
408 if err != nil {
409 return nil, fmt.Errorf("parsing commit time: %w", err)
410 }
411 commitTime := time.Unix(commitTimeUnix, 0)
412
413 hash := plumbing.NewHash(commitHash)
414
415 commitInfo := &types.LastCommitInfo{
416 Hash: hash,
417 Message: "",
418 When: commitTime,
419 }
420
421 cacheMu.Lock()
422 commitCache.Set(cacheKey, commitInfo, 1)
423 cacheMu.Unlock()
424
425 return commitInfo, nil
426}
427
428func newInfoWrapper(
429 name string,
430 prefix string,
431 entry *object.TreeEntry,
432 tree *object.Tree,
433) (*infoWrapper, error) {
434 var (
435 size int64
436 mode fs.FileMode
437 isDir bool
438 )
439
440 if entry.Mode.IsFile() {
441 file, err := tree.TreeEntryFile(entry)
442 if err != nil {
443 return nil, err
444 }
445 mode = fs.FileMode(file.Mode)
446
447 size, err = tree.Size(name)
448 if err != nil {
449 return nil, err
450 }
451 } else {
452 isDir = true
453 mode = fs.ModeDir | fs.ModePerm
454 }
455
456 fullname := path.Join(prefix, name)
457 return &infoWrapper{
458 name: fullname,
459 size: size,
460 mode: mode,
461 modTime: time.Unix(0, 0),
462 isDir: isDir,
463 }, nil
464}
465
466func (i *infoWrapper) Name() string {
467 return i.name
468}
469
470func (i *infoWrapper) Size() int64 {
471 return i.size
472}
473
474func (i *infoWrapper) Mode() fs.FileMode {
475 return i.mode
476}
477
478func (i *infoWrapper) ModTime() time.Time {
479 return i.modTime
480}
481
482func (i *infoWrapper) IsDir() bool {
483 return i.isDir
484}
485
486func (i *infoWrapper) Sys() any {
487 return nil
488}
489
490func (t *TagReference) Name() string {
491 return t.ref.Name().Short()
492}
493
494func (t *TagReference) Message() string {
495 if t.tag != nil {
496 return t.tag.Message
497 }
498 return ""
499}
500
501func (t *TagReference) TagObject() *object.Tag {
502 return t.tag
503}
504
505func (t *TagReference) Hash() plumbing.Hash {
506 return t.ref.Hash()
507}