forked from contribsys/faktory
-
Notifications
You must be signed in to change notification settings - Fork 0
/
queue_rocksdb.go
483 lines (416 loc) · 9.44 KB
/
queue_rocksdb.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
package storage
import (
"container/list"
"context"
"fmt"
"sync"
"sync/atomic"
"time"
"github.com/contribsys/faktory/util"
"github.com/contribsys/gorocksdb"
)
var (
/*
* The default maximum size of a queue.
* Further Pushes will result in an error.
*
* This is known as "back pressue" and is important to
* prevent bugs in one component from taking down the
* entire system.
*/
DefaultMaxSize = int64(100000)
)
type Backpressure struct {
QueueName string
CurrentSize int64
MaxSize int64
}
func (bp Backpressure) Error() string {
return fmt.Sprintf("%s is too large, currently %d, max size is %d", bp.QueueName, bp.CurrentSize, bp.MaxSize)
}
type rocksQueue struct {
name string
size int64
low int64
high int64
store *rocksStore
cf *gorocksdb.ColumnFamilyHandle
mu sync.Mutex
maxsz int64
waiters *list.List
waitmu sync.Mutex
done bool
}
func (q *rocksQueue) Close() {
q.mu.Lock()
defer q.mu.Unlock()
q.done = true
q.clearWaiters()
}
func (q *rocksQueue) Name() string {
return q.name
}
func (q *rocksQueue) Page(start int64, count int64, fn func(index int, k, v []byte) error) error {
index := 0
upper := upperBound(q.name)
ro := queueReadOptions(false)
ro.SetIterateUpperBound(upper)
ro.SetFillCache(false)
defer ro.Destroy()
it := q.store.db.NewIteratorCF(ro, q.cf)
defer it.Close()
prefix := append([]byte(q.name), 0xFF)
it.Seek(prefix)
if it.Err() != nil {
return it.Err()
}
// skip any before start point
for i := start; i > 0; i-- {
if !it.Valid() {
return nil
}
it.Next()
}
for ; it.Valid(); it.Next() {
if count == 0 {
break
}
if err := it.Err(); err != nil {
return err
}
k := it.Key()
v := it.Value()
value := v.Data()
key := k.Data()
err := fn(index, key, value)
index += 1
k.Free()
v.Free()
if err != nil {
return err
}
count -= 1
}
if it.Err() != nil {
return it.Err()
}
return nil
}
func (q *rocksQueue) Each(fn func(index int, k, v []byte) error) error {
return q.Page(0, -1, fn)
}
func (q *rocksQueue) Clear() (int64, error) {
count := int64(0)
// TODO impl which uses Rocks range deletes?
q.mu.Lock()
defer q.mu.Unlock()
upper := upperBound(q.name)
ro := queueReadOptions(true)
ro.SetIterateUpperBound(upper)
ro.SetFillCache(false)
defer ro.Destroy()
it := q.store.db.NewIteratorCF(ro, q.cf)
defer it.Close()
prefix := append([]byte(q.name), 0xFF)
it.Seek(prefix)
if it.Err() != nil {
return 0, it.Err()
}
if !it.Valid() {
return 0, nil
}
wo := queueWriteOptions()
defer wo.Destroy()
wb := gorocksdb.NewWriteBatch()
defer wb.Destroy()
for ; it.Valid(); it.Next() {
k := it.Key()
key := k.Data()
//util.Warnf("Queue#clear: delete %x", key)
wb.DeleteCF(q.cf, key)
k.Free()
count += 1
}
err := q.store.db.Write(wo, wb)
if err != nil {
return count, err
}
atomic.AddInt64(&q.low, count)
atomic.AddInt64(&q.size, -count)
//util.Warnf("Queue#clear: deleted %d elements from %s, size %d", count, q.name, q.size)
return count, nil
}
func (q *rocksQueue) Init() error {
q.mu = sync.Mutex{}
upper := upperBound(q.name)
ro := queueReadOptions(false)
ro.SetIterateUpperBound(upper)
ro.SetFillCache(false)
defer ro.Destroy()
var count int64
it := q.store.db.NewIteratorCF(ro, q.cf)
defer it.Close()
prefix := append([]byte(q.name), 0xFF)
it.Seek(prefix)
if it.Err() != nil {
return it.Err()
}
if it.Valid() {
k := it.Key()
key := k.Data()
//util.Warnf("Queue#init: first %x", key)
start := len(q.name) + 1
end := start + 8
q.low = toInt64(key[start:end])
k.Free()
}
for ; it.Valid(); it.Next() {
//k := it.Key()
//key := k.Data()
//util.Warnf("Queue#init: element %x", key)
//k.Free()
count += 1
}
it.SeekToLast()
if it.Err() != nil {
return it.Err()
}
if it.ValidForPrefix(prefix) {
k := it.Key()
key := k.Data()
//util.Warnf("Queue#init: %s last %x", q.name, key)
start := len(q.name) + 1
end := start + 8
q.high = toInt64(key[start:end]) + 1
k.Free()
}
q.size = count
q.waiters = list.New()
util.Debugf("Queue init: %s %d elements, %d/%d", q.name, q.size, q.low, q.high)
return nil
}
func (q *rocksQueue) Size() int64 {
return q.size
}
func (q *rocksQueue) Push(payload []byte) error {
q.mu.Lock()
defer q.mu.Unlock()
if q.size > q.maxsz {
return Backpressure{q.name, q.size, q.maxsz}
}
k := q.nextkey()
v := payload
wo := queueWriteOptions()
defer wo.Destroy()
err := q.store.db.PutCF(wo, q.cf, k, v)
if err != nil {
return err
}
//util.Warnf("Adding element %x to %s", k, q.name)
atomic.AddInt64(&q.size, 1)
q.notify()
return nil
}
// non-blocking, returns immediately if there's nothing enqueued
func (q *rocksQueue) Pop() ([]byte, error) {
q.mu.Lock()
defer q.mu.Unlock()
if q.size == 0 || q.done {
return nil, nil
}
return q._pop()
}
// caller must hold q.mu or else DOOM!
func (q *rocksQueue) _pop() ([]byte, error) {
ro := queueReadOptions(true)
ro.SetIterateUpperBound(keyfor(q.name, q.low))
defer ro.Destroy()
for {
key := keyfor(q.name, q.low)
value, err := q.store.db.GetBytesCF(ro, q.cf, key)
if err != nil {
return nil, err
}
if value == nil {
if q.low < q.high {
// If we delete an element from the queue without processing it,
// a "hole" appears in our counting. We need to iterate past the
// hole to find the next valid key.
atomic.AddInt64(&q.low, 1)
continue
}
return nil, nil
}
wo := queueWriteOptions()
defer wo.Destroy()
err = q.store.db.DeleteCF(wo, q.cf, key)
if err != nil {
return nil, err
}
atomic.AddInt64(&q.low, 1)
atomic.AddInt64(&q.size, -1)
return value, nil
}
}
type QueueWaiter struct {
ctx context.Context
notifier chan bool
}
/**
* Iterates through our current list of waiters,
* finds one whose deadline has not passed and signals
* the waiter via its channel.
*
* This is best effort: it's possible for the waiter's
* deadline to pass just as it is selected to wake up.
*/
func (q *rocksQueue) notify() {
q.waitmu.Lock()
defer q.waitmu.Unlock()
// for loop required to drain old, expired waiters
for e := q.waiters.Front(); e != nil; e = e.Next() {
qw := e.Value.(*QueueWaiter)
q.waiters.Remove(e)
deadline, _ := qw.ctx.Deadline()
if time.Now().Before(deadline) {
qw.notifier <- true
break
}
}
}
func (q *rocksQueue) clearWaiters() {
q.waitmu.Lock()
defer q.waitmu.Unlock()
for e := q.waiters.Front(); e != nil; e = e.Next() {
qw := e.Value.(*QueueWaiter)
qw.notifier <- false
}
q.waiters = list.New()
}
/*
* Waits for a job to come onto the queue. The given context
* should timeout the blocking.
*
* Waiter calls this method, blocks on a channel it creates.
* Sends that channel to the dispatcher via waiter channel.
* Dispatcher is notified of new job on queue, pulls off a waiter
* and pushes notification to its channel.
*/
func (q *rocksQueue) BPop(ctx context.Context) ([]byte, error) {
for {
q.mu.Lock()
if q.done {
q.mu.Unlock()
return nil, nil
}
if q.size > 0 {
defer q.mu.Unlock()
return q._pop()
}
q.mu.Unlock()
waiting := make(chan bool, 1)
me := &QueueWaiter{
ctx: ctx,
notifier: waiting,
}
q.waitmu.Lock()
e := q.waiters.PushBack(me)
q.waitmu.Unlock()
select {
case newjob := <-waiting:
if newjob {
continue
}
break
case <-ctx.Done():
q.waitmu.Lock()
q.waiters.Remove(e)
q.waitmu.Unlock()
return nil, nil
}
}
}
func (q *rocksQueue) Delete(keys [][]byte) error {
wb := gorocksdb.NewWriteBatch()
defer wb.Destroy()
db := q.store.db
ro := gorocksdb.NewDefaultReadOptions()
wo := gorocksdb.NewDefaultWriteOptions()
defer ro.Destroy()
defer wo.Destroy()
var count int64
q.mu.Lock()
defer q.mu.Unlock()
for _, key := range keys {
data, err := db.GetCF(ro, q.cf, key)
if err != nil {
return err
}
if data.Size() > 0 {
wb.DeleteCF(q.cf, key)
count += 1
}
data.Free()
}
util.Debugf(`Deleting %d elements from queue "%s"`, count, q.name)
err := db.Write(wo, wb)
if err == nil {
atomic.AddInt64(&q.size, -count)
}
return err
}
//////////////////////////////////////////////////
func (q *rocksQueue) nextkey() []byte {
nxtseq := atomic.AddInt64(&q.high, 1)
return keyfor(q.name, nxtseq-1)
}
/*
Each entry has a key of the form:
[queue_name] ["|"] [8 byte seq_id]
We can scan the queue by iterating over the "queue_name" prefix
*/
func keyfor(name string, seq int64) []byte {
bytes := make([]byte, len(name)+1+8)
copy(bytes, name)
len := len(name) + 1
bytes[len-1] = 0xFF
bytes[len+0] = byte(seq >> 56)
bytes[len+1] = byte((seq >> 48) & 0xFF)
bytes[len+2] = byte((seq >> 40) & 0xFF)
bytes[len+3] = byte((seq >> 32) & 0xFF)
bytes[len+4] = byte((seq >> 24) & 0xFF)
bytes[len+5] = byte((seq >> 16) & 0xFF)
bytes[len+6] = byte((seq >> 8) & 0xFF)
bytes[len+7] = byte(seq & 0xFF)
return bytes
}
func upperBound(name string) []byte {
bytes := make([]byte, 8+len(name)+1)
copy(bytes, name)
len := len(name) + 1
bytes[len-1] = 0xFF
bytes[len+0] = 0x7F
bytes[len+1] = 0xFF
bytes[len+2] = 0xFF
bytes[len+3] = 0xFF
bytes[len+4] = 0xFF
bytes[len+5] = 0xFF
bytes[len+6] = 0xFF
bytes[len+7] = 0xFF
return bytes
}
func toInt64(bytes []byte) int64 {
value := int64(bytes[0])
for i := 1; i < 8; i++ {
value = (value << 8) + int64(bytes[i])
}
return value
}
func queueReadOptions(tailing bool) *gorocksdb.ReadOptions {
ro := gorocksdb.NewDefaultReadOptions()
ro.SetTailing(tailing)
return ro
}
func queueWriteOptions() *gorocksdb.WriteOptions {
return gorocksdb.NewDefaultWriteOptions()
}