-
-
Notifications
You must be signed in to change notification settings - Fork 11
/
indexedfs.go
575 lines (486 loc) · 13.6 KB
/
indexedfs.go
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
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
package indexedfs
import (
_ "embed"
"errors"
"fmt"
"io"
"os"
"path/filepath"
"strings"
"syscall/js"
"time"
"tractor.dev/toolkit-go/engine/fs"
"tractor.dev/wanix/internal/jsutil"
)
//go:embed indexedfs.js
var jsSource []byte
// TODO: better fs errors
var helper js.Value = js.Undefined()
var ErrReadingBlob = errors.New("ErrReadingBlob")
func callHelperAwait(name string, args ...any) (value js.Value, err error) {
// jsutil.Log(name, args)
value, jsErr := jsutil.AwaitErr(helper.Call(name, args...))
if jsErr != nil {
goErrorName := jsErr.(js.Error).Get("goErrorName")
if goErrorName.Truthy() {
var goErr error
switch goErrorName.String() {
case "ErrNotExist":
goErr = fs.ErrNotExist
case "ErrExist":
goErr = fs.ErrExist
case "ErrReadingBlob":
goErr = ErrReadingBlob
default:
panic(fmt.Sprint("unexpected error:", goErrorName.String()))
}
err = errors.Join(goErr, jsErr)
} else {
err = jsErr
}
}
return value, err
}
type FS struct {
db js.Value
}
func New() (*FS, error) {
if helper.IsUndefined() {
buf := js.Global().Get("Uint8Array").New(len(jsSource))
js.CopyBytesToJS(buf, jsSource)
arr := js.Global().Get("Array").New()
arr.Call("push", buf)
blob := js.Global().Get("Blob").New(arr, map[string]any{"type": "text/javascript"})
url := js.Global().Get("URL").Call("createObjectURL", blob)
helper = jsutil.Await(js.Global().Call("import", url))
}
db, err := callHelperAwait("initialize")
if err != nil {
return nil, err
}
return &FS{db: db}, nil
}
func (ifs *FS) Chmod(name string, mode fs.FileMode) error {
if !fs.ValidPath(name) {
return &fs.PathError{Op: "chmod", Path: name, Err: fs.ErrInvalid}
}
updateFunc := js.FuncOf(func(this js.Value, args []js.Value) any {
file := args[0]
file.Set("perms", uint32(mode.Perm()))
file.Set("ctime", time.Now().Unix())
return file
})
defer updateFunc.Release()
if _, err := callHelperAwait("updateFile", ifs.db, name, updateFunc); err != nil {
return &fs.PathError{Op: "chmod", Path: name, Err: err}
}
return nil
}
func (ifs *FS) Chown(name string, uid, gid int) error {
return fs.ErrPermission // TODO: maybe just a no-op?
}
func (ifs *FS) Chtimes(name string, atime time.Time, mtime time.Time) error {
if !fs.ValidPath(name) {
return &fs.PathError{Op: "chtimes", Path: name, Err: fs.ErrInvalid}
}
updateFunc := js.FuncOf(func(this js.Value, args []js.Value) any {
file := args[0]
file.Set("atime", atime.Unix())
file.Set("mtime", mtime.Unix())
file.Set("ctime", time.Now().Unix())
return file
})
defer updateFunc.Release()
if _, err := callHelperAwait("updateFile", ifs.db, name, updateFunc); err != nil {
return &fs.PathError{Op: "chtimes", Path: name, Err: err}
}
return nil
}
func (ifs *FS) Create(name string) (fs.File, error) {
return ifs.OpenFile(name, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, 0644)
}
func (ifs *FS) Mkdir(name string, perm fs.FileMode) error {
if !fs.ValidPath(name) {
return &fs.PathError{Op: "mkdir", Path: name, Err: fs.ErrInvalid}
}
dir := filepath.Dir(name)
if dir != "." && dir != "/" {
exists, err := fs.DirExists(ifs, dir)
if err != nil {
return &fs.PathError{Op: "mkdir", Path: name, Err: err}
}
if !exists {
return &fs.PathError{Op: "mkdir", Path: dir, Err: fs.ErrInvalid}
}
}
_, err := callHelperAwait("addFile", ifs.db, name, uint32(perm), true, time.Now().Unix())
if err != nil {
return &fs.PathError{Op: "mkdir", Path: name, Err: err}
}
return nil
}
func (ifs *FS) MkdirAll(path string, perm fs.FileMode) error {
if !fs.ValidPath(path) {
return &fs.PathError{Op: "mkdirAll", Path: path, Err: fs.ErrInvalid}
}
var pp []string
for _, p := range strings.Split(path, "/") {
if p == "" {
continue
}
pp = append(pp, p)
dir := filepath.Join(pp...)
exists, err := fs.DirExists(ifs, dir)
if err != nil {
return &fs.PathError{Op: "mkdirall", Path: dir, Err: err}
}
if !exists {
if err := ifs.Mkdir(dir, perm); err != nil {
return &fs.PathError{Op: "mkdirall", Path: dir, Err: err}
}
}
}
return nil
}
func (ifs *FS) Open(name string) (fs.File, error) {
return ifs.OpenFile(name, os.O_RDONLY, 0)
}
func (ifs *FS) OpenFile(name string, flag int, perm fs.FileMode) (fs.File, error) {
if !fs.ValidPath(name) {
return nil, &fs.PathError{Op: "open", Path: name, Err: fs.ErrInvalid}
}
if flag&os.O_SYNC > 0 {
return nil, &fs.PathError{Op: "open", Path: name, Err: fmt.Errorf("%w O_SYNC", errors.ErrUnsupported)}
}
// TODO:
// make sure we're using the right permissions
// profit?
var (
file fs.File = nil
key js.Value
err error = nil
)
key, err = callHelperAwait("getFileKey", ifs.db, name)
if err == nil {
file = &indexedFile{name: name, key: key.Int(), ifs: ifs, flags: flag}
}
if err == nil && (flag&(os.O_EXCL|os.O_CREATE) == (os.O_EXCL | os.O_CREATE)) {
return nil, &fs.PathError{Op: "open", Path: name, Err: fs.ErrExist}
}
if err != nil {
if errors.Is(err, fs.ErrNotExist) {
if flag&os.O_CREATE > 0 {
key, err = callHelperAwait("addFile", ifs.db, name, uint32(perm), perm.IsDir(), time.Now().Unix())
if err != nil {
return nil, &fs.PathError{Op: "open", Path: name, Err: err}
}
file = &indexedFile{name: name, key: key.Int(), ifs: ifs, flags: flag}
} else {
return nil, &fs.PathError{Op: "open", Path: name, Err: fs.ErrNotExist}
}
} else {
return nil, &fs.PathError{Op: "open", Path: name, Err: err}
}
}
if flag&os.O_APPEND > 0 {
if _, err = file.(*indexedFile).Seek(0, io.SeekEnd); err != nil {
return file, err
}
}
if flag&os.O_TRUNC > 0 {
if err = file.(*indexedFile).Truncate(); err != nil {
return file, err
}
}
// if we didn't just create the file, update atime
// TODO: this isn't actually checking if we created a file.
if flag&os.O_CREATE == 0 {
updateFunc := js.FuncOf(func(this js.Value, args []js.Value) any {
file := args[0]
file.Set("atime", time.Now().Unix())
return file
})
defer updateFunc.Release()
if _, err = callHelperAwait("updateFile", ifs.db, name, updateFunc); err != nil {
return nil, &fs.PathError{Op: "open", Path: name, Err: err}
}
}
return file, nil
}
func (ifs *FS) Remove(name string) error {
if !fs.ValidPath(name) {
return &fs.PathError{Op: "remove", Path: name, Err: fs.ErrInvalid}
}
key, err := callHelperAwait("getFileKey", ifs.db, name)
if err != nil {
return &fs.PathError{Op: "remove", Path: name, Err: err}
}
if _, err = callHelperAwait("deleteFile", ifs.db, key); err != nil {
return &fs.PathError{Op: "remove", Path: name, Err: err}
}
return nil
}
func (ifs *FS) RemoveAll(path string) error {
if !fs.ValidPath(path) {
return &fs.PathError{Op: "removeAll", Path: path, Err: fs.ErrInvalid}
}
if _, err := callHelperAwait("deleteAll", ifs.db, path); err != nil {
return &fs.PathError{Op: "removeAll", Path: path, Err: err}
}
return nil
}
func (ifs *FS) Rename(oldname, newname string) error {
if !fs.ValidPath(oldname) {
return &fs.PathError{Op: "rename", Path: oldname, Err: fs.ErrInvalid}
}
if !fs.ValidPath(newname) {
return &fs.PathError{Op: "rename", Path: newname, Err: fs.ErrInvalid}
}
if oldname == newname {
return nil
}
oldKey, err := callHelperAwait("getFileKey", ifs.db, oldname)
if err != nil {
return &fs.PathError{Op: "rename", Path: oldname, Err: err}
}
// if new-file already exists, delete it so we can replace it with old-file
newKey, err := callHelperAwait("getFileKey", ifs.db, newname)
if err == nil {
_, err = callHelperAwait("deleteFile", ifs.db, newKey)
if err != nil {
return &fs.PathError{Op: "rename", Path: oldname, Err: err}
}
}
// TODO: handle case where oldname and newname are directories.
// Do we move oldname and its contents to newname/oldname?
// Should we just match the man page?
// "oldpath can specify a directory. In this case, newpath must
// either not exist, or it must specify an empty directory."
// (https://man7.org/linux/man-pages/man2/rename.2.html)
updateFunc := js.FuncOf(func(this js.Value, args []js.Value) any {
file := args[0]
file.Set("path", newname)
file.Set("ctime", time.Now().Unix())
return file
})
defer updateFunc.Release()
if _, err = callHelperAwait("updateFile", ifs.db, oldKey, updateFunc); err != nil {
return &fs.PathError{Op: "rename", Path: oldname, Err: err}
}
return nil
}
func (ifs *FS) Stat(name string) (fs.FileInfo, error) {
if !fs.ValidPath(name) {
return nil, &fs.PathError{Op: "stat", Path: name, Err: fs.ErrInvalid}
}
f, err := callHelperAwait("getFileByPath", ifs.db, name)
if err != nil {
return nil, &fs.PathError{Op: "stat", Path: name, Err: fs.ErrNotExist}
}
return &indexedInfo{
name: filepath.Base(f.Get("path").String()),
size: int64(f.Get("size").Int()),
isDir: f.Get("isdir").Bool(),
modTime: int64(f.Get("mtime").Int()),
}, nil
}
func (ifs *FS) ReadDir(name string) ([]fs.DirEntry, error) {
if !fs.ValidPath(name) {
return nil, &fs.PathError{Op: "readDir", Path: name, Err: fs.ErrInvalid}
}
entries, err := callHelperAwait("getDirEntries", ifs.db, name)
if err != nil {
return nil, &fs.PathError{Op: "readdir", Path: name, Err: err}
}
var fsEntries []fs.DirEntry
for i := 0; i < entries.Length(); i++ {
e := entries.Index(i)
fsEntries = append(fsEntries, &indexedInfo{
name: filepath.Base(e.Get("path").String()),
size: int64(e.Get("size").Int()),
isDir: e.Get("isdir").Bool(),
modTime: int64(e.Get("mtime").Int()),
})
}
return fsEntries, nil
}
type indexedFile struct {
name string
key int
ifs *FS
flags int
offset int64
// TODO: see if read/write caches can be merged
// used internally by getData()
readCache []byte
outdatedRead bool
// used internally by Write() and Sync()
writeCache []byte
dirty bool
}
func (f *indexedFile) ReadDir(n int) ([]fs.DirEntry, error) {
return f.ifs.ReadDir(f.name)
}
func (f *indexedFile) getData() ([]byte, error) {
if f.outdatedRead || f.readCache == nil {
// Deliberately not updating atime, as that can get slow fast.
// Aiming for posix-like, not compliant.
data, err := callHelperAwait("readFile", f.ifs.db, f.key)
if err != nil {
return nil, err
}
f.outdatedRead = false
if data.IsNull() {
f.readCache = []byte{}
} else {
f.readCache = make([]byte, data.Length())
js.CopyBytesToGo(f.readCache, data)
}
}
return f.readCache, nil
}
func (f *indexedFile) Close() error {
f.offset = 0
if f.dirty {
return f.Sync()
}
// f.readCache = nil
// f.ifs = nil
// f = nil
return nil
}
func (f *indexedFile) Read(p []byte) (n int, err error) {
if f.flags&os.O_WRONLY > 0 {
return 0, fs.ErrPermission
}
data, err := f.getData()
if err != nil {
return 0, err
}
if f.offset >= int64(len(data)) {
return 0, io.EOF
}
rest := data[f.offset:]
if len(rest) < len(p) {
n = len(rest)
} else {
n = len(p)
}
copy(p, rest[:n])
f.offset += int64(n)
return n, nil
}
func (f *indexedFile) Write(p []byte) (n int, err error) {
if f.flags&os.O_RDONLY > 0 {
return 0, fs.ErrPermission
}
if f.writeCache == nil {
if f.writeCache, err = f.getData(); err != nil {
return 0, err
}
}
writeEnd := f.offset + int64(len(p))
if writeEnd > int64(cap(f.writeCache)) {
newCapacity := int64(cap(f.writeCache))*2 + 1
for ; writeEnd > newCapacity; newCapacity *= 2 {
}
newCache := make([]byte, len(f.writeCache), newCapacity)
copy(newCache, f.writeCache)
f.writeCache = newCache
}
copy(f.writeCache[f.offset:writeEnd], p)
if len(f.writeCache) < int(writeEnd) {
f.writeCache = f.writeCache[:writeEnd]
}
f.offset = writeEnd
f.dirty = true
return len(p), nil
}
func (f *indexedFile) Truncate() error {
f.Seek(0, io.SeekStart)
f.writeCache = []byte{}
return f.Sync()
}
func (f *indexedFile) Sync() error {
if !f.dirty {
return nil
}
updateFunc := js.FuncOf(func(this js.Value, args []js.Value) any {
file := args[0]
mime := map[string]interface{}{
"type": "application/octet-stream",
}
buf := js.Global().Get("Uint8Array").New(len(f.writeCache))
js.CopyBytesToJS(buf, f.writeCache)
file.Set("blob", js.Global().Get("Blob").New([]any{buf}, mime))
file.Set("size", len(f.writeCache))
file.Set("mtime", time.Now().Unix())
file.Set("ctime", time.Now().Unix())
file.Set("atime", time.Now().Unix())
return file
})
defer updateFunc.Release()
_, err := callHelperAwait("updateFile", f.ifs.db, f.key, updateFunc)
if err != nil {
return &fs.PathError{Op: "sync", Path: f.name, Err: err}
}
f.dirty = false
f.outdatedRead = true
return nil
}
func (f *indexedFile) Stat() (fs.FileInfo, error) {
return f.ifs.Stat(f.name)
}
func (f *indexedFile) Seek(offset int64, whence int) (int64, error) {
switch whence {
case io.SeekStart:
f.offset = offset
case io.SeekCurrent:
f.offset += offset
case io.SeekEnd:
if d, err := f.getData(); err == nil {
f.offset = int64(len(d)) + offset
} else {
return 0, &fs.PathError{Op: "seek", Path: f.name, Err: err}
}
}
if f.offset < 0 {
f.offset = 0
return 0, &fs.PathError{Op: "seek", Path: f.name, Err: fmt.Errorf("%w: resultant offset cannot be negative", fs.ErrInvalid)}
}
return f.offset, nil
}
type indexedInfo struct {
name string
size int64
isDir bool
modTime int64
}
func (i *indexedInfo) Name() string {
return i.name
}
func (i *indexedInfo) Size() int64 {
return i.size
}
func (i *indexedInfo) Mode() fs.FileMode {
if i.isDir {
return 0755 | os.ModeDir
}
return 0644
}
func (i *indexedInfo) ModTime() time.Time {
return time.Unix(i.modTime, 0)
}
func (i *indexedInfo) IsDir() bool {
return i.isDir
}
func (i *indexedInfo) Sys() any {
return nil
}
// these allow it to act as DirInfo as well
func (i *indexedInfo) Info() (fs.FileInfo, error) {
return i, nil
}
func (i *indexedInfo) Type() fs.FileMode {
return i.Mode()
}