Repository navigation
Expand file tree
/
Copy pathdisk-cache-utils.go
More file actions
506 lines (457 loc) · 11.8 KB
/
Copy pathdisk-cache-utils.go
File metadata and controls
506 lines (457 loc) · 11.8 KB
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
/*
* MinIO Cloud Storage, (C) 2019 MinIO, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package cmd
import (
"container/list"
"encoding/hex"
"errors"
"fmt"
"io"
"math"
"os"
"path"
"strconv"
"strings"
"time"
"github.com/minio/minio/cmd/crypto"
)
// CacheStatusType - whether the request was served from cache.
type Cac
8000
heStatusType string
const (
// CacheHit - whether object was served from cache.
CacheHit CacheStatusType = "HIT"
// CacheMiss - object served from backend.
CacheMiss CacheStatusType = "MISS"
)
func (c CacheStatusType) String() string {
if c != "" {
return string(c)
}
return string(CacheMiss)
}
type cacheControl struct {
expiry time.Time
maxAge int
sMaxAge int
minFresh int
maxStale int
noStore bool
onlyIfCached bool
noCache bool
}
func (c *cacheControl) isStale(modTime time.Time) bool {
if c == nil {
return false
}
// response will never be stale if only-if-cached is set
if c.onlyIfCached {
return false
}
// Cache-Control value no-store indicates never cache
if c.noStore {
return true
}
// Cache-Control value no-cache indicates cache entry needs to be revalidated before
// serving from cache
if c.noCache {
return true
}
now := time.Now()
if c.sMaxAge > 0 && c.sMaxAge < int(now.Sub(modTime).Seconds()) {
return true
}
if c.maxAge > 0 && c.maxAge < int(now.Sub(modTime).Seconds()) {
return true
}
if !c.expiry.Equal(time.Time{}) && c.expiry.Before(time.Now().Add(time.Duration(c.maxStale))) {
return true
}
if c.minFresh > 0 && c.minFresh <= int(now.Sub(modTime).Seconds()) {
return true
}
return false
}
// returns struct with cache-control settings from user metadata.
func cacheControlOpts(o ObjectInfo) *cacheControl {
c := cacheControl{}
m := o.UserDefined
if !o.Expires.Equal(timeSentinel) {
c.expiry = o.Expires
}
var headerVal string
for k, v := range m {
if strings.ToLower(k) == "cache-control" {
headerVal = v
}
}
if headerVal == "" {
return nil
}
headerVal = strings.ToLower(headerVal)
headerVal = strings.TrimSpace(headerVal)
vals := strings.Split(headerVal, ",")
for _, val := range vals {
val = strings.TrimSpace(val)
if val == "no-store" {
c.noStore = true
continue
}
if val == "only-if-cached" {
c.>
continue
}
if val == "no-cache" {
c.noCache = true
continue
}
p := strings.Split(val, "=")
if len(p) != 2 {
continue
}
if p[0] == "max-age" ||
p[0] == "s-maxage" ||
p[0] == "min-fresh" ||
p[0] == "max-stale" {
i, err := strconv.Atoi(p[1])
if err != nil {
return nil
}
if p[0] == "max-age" {
c.maxAge = i
}
if p[0] == "s-maxage" {
c.sMaxAge = i
}
if p[0] == "min-fresh" {
c.minFresh = i
}
if p[0] == "max-stale" {
c.maxStale = i
}
}
}
return &c
}
// backendDownError returns true if err is due to backend failure or faulty disk if in server mode
func backendDownError(err error) bool {
_, backendDown := err.(BackendDown)
return backendDown || IsErr(err, baseErrs...)
}
// IsCacheable returns if the object should be saved in the cache.
func (o ObjectInfo) IsCacheable() bool {
if globalCacheKMS != nil {
return true
}
_, ok := crypto.IsEncrypted(o.UserDefined)
return !ok
}
// reads file cached on disk from offset upto length
func readCacheFileStream(filePath string, offset, length int64) (io.ReadCloser, error) {
if filePath == "" || offset < 0 {
return nil, errInvalidArgument
}
if err := checkPathLength(filePath); err != nil {
return nil, err
}
fr, err := os.Open(filePath)
if err != nil {
return nil, osErrToFileErr(err)
}
// Stat to get the size of the file at path.
st, err := fr.Stat()
if err != nil {
err = osErrToFileErr(err)
return nil, err
}
if err = os.Chtimes(filePath, time.Now(), st.ModTime()); err != nil {
return nil, err
}
// Verify if its not a regular file, since subsequent Seek is undefined.
if !st.Mode().IsRegular() {
return nil, errIsNotRegular
}
if err = os.Chtimes(filePath, time.Now(), st.ModTime()); err != nil {
return nil, err
}
// Seek to the requested offset.
if offset > 0 {
_, err = fr.Seek(offset, io.SeekStart)
if err != nil {
return nil, err
}
}
return struct {
io.Reader
io.Closer
}{Reader: io.LimitReader(fr, length), Closer: fr}, nil
}
func isCacheEncrypted(meta map[string]string) bool {
_, ok := meta[SSECacheEncrypted]
return ok
}
// decryptCacheObjectETag tries to decrypt the ETag saved in encrypted format using the cache KMS
func decryptCacheObjectETag(info *ObjectInfo) error {
// Directories are never encrypted.
if info.IsDir {
return nil
}
encrypted := crypto.S3.IsEncrypted(info.UserDefined) && isCacheEncrypted(info.UserDefined)
switch {
case encrypted:
if globalCacheKMS == nil {
return errKMSNotConfigured
}
keyID, kmsKey, sealedKey, err := crypto.S3.ParseMetadata(info.UserDefined)
if err != nil {
return err
}
extKey, err := globalCacheKMS.DecryptKey(keyID, kmsKey, crypto.Context{info.Bucket: path.Join(info.Bucket, info.Name)})
if err != nil {
return err
}
var objectKey crypto.ObjectKey
if err = objectKey.Unseal(extKey, sealedKey, crypto.S3.String(), info.Bucket, info.Name); err != nil {
return err
}
etagStr := tryDecryptETag(objectKey[:], info.ETag, false)
// backend ETag was hex encoded before encrypting, so hex decode to get actual ETag
etag, err := hex.DecodeString(etagStr)
if err != nil {
return err
}
info.ETag = string(etag)
return nil
}
return nil
}
func isMetadataSame(m1, m2 map[string]string) bool {
if m1 == nil && m2 == nil {
return true
}
if (m1 == nil && m2 != nil) || (m2 == nil && m1 != nil) {
return false
}
if len(m1) != len(m2) {
return false
}
for k1, v1 := range m1 {
if v2, ok := m2[k1]; !ok || (v1 != v2) {
return false
}
}
return true
}
type fileScorer struct {
saveBytes uint64
now int64
maxHits int
// 1/size for consistent score.
sizeMult float64
// queue is a linked list of files we want to delete.
// The list is kept sorted according to score, highest at top, lowest at bottom.
queue list.List
queuedBytes uint64
seenBytes uint64
}
type queuedFile struct {
name string
versionID string
size uint64
score float64
}
// newFileScorer allows to collect files to save a specific number of bytes.
// Each file is assigned a score based on its age, size and number of hits.
// A list of files is maintained
func newFileScorer(saveBytes uint64, now int64, maxHits int) (*fileScorer, error) {
if saveBytes == 0 {
return nil, errors.New("newFileScorer: saveBytes = 0")
}
if now < 0 {
return nil, errors.New("newFileScorer: now < 0")
}
if maxHits <= 0 {
return nil, errors.New("newFileScorer: maxHits <= 0")
}
f := fileScorer{saveBytes: saveBytes, maxHits: maxHits, now: now, sizeMult: 1 / float64(saveBytes)}
f.queue.Init()
return &f, nil
}
func (f *fileScorer) addFile(name string, accTime time.Time, size int64, hits int) {
f.addFileWithObjInfo(ObjectInfo{
Name: name,
AccTime: accTime,
Size: size,
}, hits)
}
func (f *fileScorer) addFileWithObjInfo(objInfo ObjectInfo, hits int) {
// Calculate how much we want to delete this object.
file := queuedFile{
name: objInfo.Name,
versionID: objInfo.VersionID,
size: uint64(objInfo.Size),
}
f.seenBytes += uint64(objInfo.Size)
var score float64
if objInfo.ModTime.IsZero() {
// Mod time is not available with disk cache use atime.
score = float64(f.now - objInfo.AccTime.Unix())
} else {
// if not used mod time when mod time is available.
score = float64(f.now - objInfo.ModTime.Unix())
}
// Size as fraction of how much we want to save, 0->1.
szWeight := math.Max(0, (math.Min(1, float64(file.size)*f.sizeMult)))
// 0 at f.maxHits, 1 at 0.
hitsWeight := (1.0 - math.Max(0, math.Min(1.0, float64(hits)/float64(f.maxHits))))
file.score = score * (1 + 0.25*szWeight + 0.25*hitsWeight)
// If we still haven't saved enough, just add the file
if f.queuedBytes < f.saveBytes {
f.insertFile(file)
f.trimQueue()
return
}
// If we score less than the worst, don't insert.
worstE := f.queue.Back()
if worstE != nil && file.score < worstE.Value.(queuedFile).score {
return
}
f.insertFile(file)
f.trimQueue()
}
// adjustSaveBytes allows to adjust the number of bytes to save.
// This can be used to adjust the count on the fly.
// Returns true if there still is a need to delete files (n+saveBytes >0),
// false if no more bytes needs to be saved.
func (f *fileScorer) adjustSaveBytes(n int64) bool {
if int64(f.saveBytes)+n <= 0 {
f.saveBytes = 0
f.trimQueue()
return false
}
if n < 0 {
f.saveBytes -= ^uint64(n - 1)
} else {
f.saveBytes += uint64(n)
}
if f.saveBytes == 0 {
f.queue.Init()
f.saveBytes = 0
return false
}
if n < 0 {
f.trimQueue()
}
return true
}
// insertFile will insert a file into the list, sorted by its score.
func (f *fileScorer) insertFile(file queuedFile) {
e := f.queue.Front()
for e != nil {
v := e.Value.(queuedFile)
if v.score < file.score {
break
}
e = e.Next()
}
f.queuedBytes += file.size
// We reached the end.
if e == nil {
f.queue.PushBack(file)
return
}
f.queue.InsertBefore(file, e)
}
// trimQueue will trim the back of queue and still keep below wantSave.
func (f *fileScorer) trimQueue() {
for {
e := f.queue.Back()
if e == nil {
return
}
v := e.Value.(queuedFile)
if f.queuedBytes-v.size < f.saveBytes {
return
}
f.queue.Remove(e)
f.queuedBytes -= v.size
}
}
// fileObjInfos returns all queued file object infos
func (f *fileScorer) fileObjInfos() []ObjectInfo {
res := make([]ObjectInfo, 0, f.queue.Len())
e := f.queue.Front()
for e != nil {
qfile := e.Value.(queuedFile)
res = append(res, ObjectInfo{
Name: qfile.name,
Size: int64(qfile.size),
VersionID: qfile.versionID,
})
e = e.Next()
}
return res
}
func (f *fileScorer) purgeFunc(p func(qfile queuedFile)) {
e := f.queue.Front()
for e != nil {
p(e.Value.(queuedFile))
e = e.Next()
}
}
// fileNames returns all queued file names.
func (f *fileScorer) fileNames() []string {
res := make([]string, 0, f.queue.Len())
e := f.queue.Front()
for e != nil {
res = append(res, e.Value.(queuedFile).name)
e = e.Next()
}
return res
}
func (f *fileScorer) reset() {
f.queue.Init()
f.queuedBytes = 0
}
func (f *fileScorer) queueString() string {
var res strings.Builder
e := f.queue.Front()
i := 0
for e != nil {
v := e.Value.(queuedFile)
if i > 0 {
res.WriteByte('\n')
}
res.WriteString(fmt.Sprintf("%03d: %s (score: %.3f, bytes: %d)", i, v.name, v.score, v.size))
i++
e = e.Next()
}
return res.String()
}
// bytesToClear() returns the number of bytes to clear to reach low watermark
// w.r.t quota given disk total and free space, quota in % allocated to cache
// and low watermark % w.r.t allowed quota.
// If the high watermark hasn't been reached 0 will be returned.
func bytesToClear(total, free int64, quotaPct, lowWatermark, highWatermark uint64) uint64 {
used := total - free
quotaAllowed := total * (int64)(quotaPct) / 100
highWMUsage := total * (int64)(highWatermark*quotaPct) / (100 * 100)
if used < highWMUsage {
return 0
}
// Return bytes needed to reach low watermark.
lowWMUsage := total * (int64)(lowWatermark*quotaPct) / (100 * 100)
return (uint64)(math.Min(float64(quotaAllowed), math.Max(0.0, float64(used-lowWMUsage))))
}