-
Notifications
You must be signed in to change notification settings - Fork 35
/
btr0cur.cc
2210 lines (1736 loc) · 59.1 KB
/
btr0cur.cc
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
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
#include "btr0cur.h"
#include "page0page.h"
#include "rem0rec.h"
#include "rem0cmp.h"
#include "btr0btr.h"
#include "btr0sea.h"
#include "row0upd.h"
#include "trx0rec.h"
#include "que0que.h"
#include "row0row.h"
#include "srv0srv.h"
#include "ibuf0ibuf.h"
#include "lock0lock.h"
ibool btr_cur_print_record_ops = FALSE;
ulint btr_cur_rnd = 0;
ulint btr_cur_n_non_sea = 0;
ulint btr_cur_n_sea = 0;
ulint btr_cur_n_non_sea_old = 0;
ulint btr_cur_n_sea_old = 0;
/*页重组因子*/
#define BTR_CUR_PAGE_REORGANIZE_LIMIT (UNIV_PAGE_SIZE / 32)
#define BTR_KEY_VAL_ESTIMATE_N_PAGES 8
/*BLOB列的头结构*/
#define BTR_BLOB_HDR_PART_LEN 0 /*blob在对应页中的长度*/
#define BTR_BLOB_HDR_NEXT_PAGE_NO 4 /*下一个存有blob数据的page no*/
#define BTR_BLOB_HDR_SIZE 8
static void btr_cur_add_path_info(btr_cur_t* cursor, ulint height, ulint root_height);
static void btr_rec_free_updated_extern_fields(dict_index_t* index, rec_t* rec, upd_t* update, ibool do_not_free_inherited, mtr_t* mtr);
static ulint btr_rec_get_externally_stored_len(rec_t* rec);
/*对page做互斥latch并发*/
static void btr_cur_latch_leaves(dict_tree_t* tree, page_t* page, ulint space, ulint page_no, ulint latch_mode, btr_cur_t* cursor, mtr_t* mtr)
{
ulint left_page_no;
ulint right_page_no;
ut_ad(tree && page && mtr);
if(latch_mode == BTR_SEARCH_LEAF) /*查找时，可以直接获取一个S-LATCH,*/
btr_page_get(space, page_no, RW_S_LATCH, mtr);
else if(latch_mode == BTR_MODIFY_LEAF) /*叶子节点修改，直接对叶子节点x-latch即可*/
btr_page_get(space, page_no, RW_X_LATCH, mtr);
else if(latch_mode == BTR_MODIFY_TREE){ /*分别会获取前后两页和自己的x-latch*/
left_page_no = btr_page_get_prev(page, mtr);
if(left_pge_no != FIL_NULL) /*对前一页获取一个X-LATCH*/
btr_page_get(space, left_page_no, RW_X_LATCH, mtr);
btr_page_get(space, page_no, RW_X_LATCH, mtr);
/*对后一个页也获取一个X-LATCH*/
right_page_no = btr_page_get_next(page, mtr);
if(right_page_no != FIL_NULL)
btr_page_get(space, right_page_no, RW_X_LATCH, mtr);
}
else if(latch_mode == BTR_SEARCH_PREV){ /*搜索前一页，对前一页加上一个s-latch*/
left_page_no = btr_page_get_prev(page, mtr);
if(left_page_no != FIL_NULL)
cursor->left_page = btr_page_get(space, left_page_no, RW_S_LATCH, mtr);
btr_page_get(space, page_no, RW_S_LATCH, mtr);
}
else if(latch_mode == BTR_MODIFY_PREV){ /*更改前一页，对前一页加上一个x-latch*/
left_page_no = btr_page_get_prev(page, mtr);
if(left_page_no != FIL_NULL)
cursor->left_page = btr_page_get(space, left_page_no, RW_X_LATCH, mtr);
btr_page_get(space, page_no, RW_X_LATCH, mtr);
}
else
ut_error;
}
void btr_cur_search_to_nth_level(dict_index_t* index, ulint level, dtuple_t* tuple, ulint mode, ulint latch_mode,
btr_cur_t* cursor, ulint has_search_latch, mtr_t* mtr)
{
dict_tree_t* tree;
page_cur_t* page_cursor;
page_t* page;
page_t* guess;
rec_t* node_ptr;
ulint page_no;
ulint space;
ulint up_match;
ulint up_bytes;
ulint low_match;
ulint low_bytes;
ulint height;
ulint savepoint;
ulint rw_latch;
ulint page_mode;
ulint insert_planned;
ulint buf_mode;
ulint estimate;
ulint ignore_sec_unique;
ulint root_height;
btr_search_t* info;
ut_ad(level == 0 || mode == PAGE_CUR_LE);
ut_ad(dict_tree_check_search_tuple(index->tree, tuple));
ut_ad(!(index->type & DICT_IBUF) || ibuf_inside());
ut_ad(dtuple_check_typed(tuple));
insert_planned = latch_mode & BTR_INSERT;
estimate = latch_mode & BTR_ESTIMATE; /*预估计算的动作*/
ignore_sec_unique = latch_mode & BTR_IGNORE_SEC_UNIQUE;
latch_mode = latch_mode & ~(BTR_INSERT | BTR_ESTIMATE | BTR_IGNORE_SEC_UNIQUE);
ut_ad(!insert_planned || mode == PAGE_CUR_LE);
cursor->flag = BTR_CUR_BINARY;
cursor->index = index;
/*在自适应HASH表中查找*/
info = btr_search_get_info(index);
guess = info->root_guess;
#ifdef UNIV_SEARCH_PERF_STAT
info->n_searches++;
#endif
/*在自适应hash中找到了对应的记录*/
if (btr_search_latch.writer == RW_LOCK_NOT_LOCKED
&& latch_mode <= BTR_MODIFY_LEAF && info->last_hash_succ
&& !estimate
&& btr_search_guess_on_hash(index, info, tuple, mode, latch_mode, cursor, has_search_latch, mtr)) {
ut_ad(cursor->up_match != ULINT_UNDEFINED || mode != PAGE_CUR_GE);
ut_ad(cursor->up_match != ULINT_UNDEFINED || mode != PAGE_CUR_LE);
ut_ad(cursor->low_match != ULINT_UNDEFINED || mode != PAGE_CUR_LE);
btr_cur_n_sea++;
return;
}
btr_cur_n_sea ++;
if(has_search_latch)
rw_lock_s_unlock(&btr_search_latch);
/*设置一个mini transcation的保存点，以便mtr rollback*/
savepoint = mtr_set_savepoint(mtr);
tree = index->tree;
/*获取一个x-latch,更改有可能会更改索引*/
if(latch_mode == BTR_MODIFY_TREE)
mtr_x_lock(dict_tree_get_lock(tree), mtr);
else if(latch_mode == BTR_CONT_MODIFY_TREE)
ut_ad(mtr_memo_contains(mtr, dict_tree_get_lock(tree), MTR_MEMO_X_LOCK));
else /*对tree 索引获取一个s-latch*/
mtr_s_lock(dict_tree_get_lock(tree), mtr);
page_cursor = btr_cur_get_page_cur(cursor);
space = dict_tree_get_space(tree);
page_no = dict_tree_get_page(tree);
up_match = 0;
up_bytes = 0;
low_match = 0;
low_bytes = 0;
height = ULINT_UNDEFINED;
rw_latch = RW_NO_LATCH;
buf_mode = BUF_GET;
/*确定page记录的匹配模式*/
if (mode == PAGE_CUR_GE)
page_mode = PAGE_CUR_L;
else if (mode == PAGE_CUR_G)
page_mode = PAGE_CUR_LE;
else if (mode == PAGE_CUR_LE)
page_mode = PAGE_CUR_LE;
else {
ut_ad(mode == PAGE_CUR_L);
page_mode = PAGE_CUR_L;
}
for(;;){
if(height == 0 && latch_mode <= BTR_MODIFY_LEAF){
rw_latch = latch_mode;
/*尝试将page插入到ibuffer当中*/
if(insert_planned && ibuf_should_try(index, ignore_sec_unique))
buf_mode = BUF_GET_IF_IN_POOL;
}
retry_page_get:
page = buf_page_get_gen(space, page_no, rw_latch, guess, buf_mode, __FILE__, __LINE__, mtr);
if(page == NULL){
ut_ad(buf_mode == BUF_GET_IF_IN_POOL);
ut_ad(insert_planned);
ut_ad(cursor->thr);
/*page不能插入到insert buffer中,将会重试,知道page插入到ibuf中*/
if(ibuf_should_try(index, ignore_sec_unique) && ibuf_insert(tuple, index, space, page_no, cursor->thr)){
cursor->flag = BTR_CUR_INSERT_TO_IBUF;
return ;
}
buf_mode = BUF_GET;
goto retry_page_get;
}
ut_ad(0 == ut_dulint_cmp(tree->id, btr_page_get_index_id(page)));
if(height == ULINT_UNDEFINED){
height = btr_page_get_level(page, mtr);
root_height = height;
cursor->tree_height = root_height + 1;
if(page != guess)
info->root_guess = page;
}
if(height == 0){
if(rw_latch == RW_NO_LATCH)
btr_cur_latch_leaves(tree, page, space, page_no, latch_mode, cursor, mtr);
/*释放savepoint以下的mtr latch*/
if(latch_mode != BTR_MODIFY_TREE && latch_mode != BTR_CONT_MODIFY_TREE)
mtr_release_s_latch_at_savepoint(mtr, savepoint, dict_tree_get_lock(tree));
page_mode = mode;
}
/*在页中进行二分查找对应的记录,这个只是找page node ptr记录*/
page_cur_search_with_match(page, tuple, page_mode, &up_match, &up_bytes, &low_match, &low_bytes, page_cursor);
if(estimate) /*估算row数*/
btr_cur_add_path_info(cursor, height, root_height);
if(level == height){ /*已经找到对应的层了，不需要深入更低层上*/
if(level > 0)
btr_page_get(space, page_no, RW_X_LATCH, mtr);
break;
}
ut_ad(height > 0);
height --;
guess = NULL;
node_ptr = page_cur_get_rec(page_cursor);
/*获取孩子节点的page no*/
page_no = btr_node_ptr_get_child_page_no(node_ptr);
}
if(level == 0){
cursor->low_match = low_match;
cursor->low_bytes = low_bytes;
cursor->up_match = up_match;
cursor->up_bytes = up_bytes;
/*更新自适应HASH索引*/
btr_search_info_update(index, cursor);
ut_ad(cursor->up_match != ULINT_UNDEFINED || mode != PAGE_CUR_GE);
ut_ad(cursor->up_match != ULINT_UNDEFINED || mode != PAGE_CUR_LE);
ut_ad(cursor->low_match != ULINT_UNDEFINED || mode != PAGE_CUR_LE);
}
if(has_search_latch)
rw_lock_s_lock(&btr_search_latch);
}
/*将btree cursor定位到index索引范围的开始或者末尾，from_left = TRUE，表示定位到最前面*/
void btr_cur_open_at_index_side(ibool from_left, dict_index_t* index, ulint latch_mode, btr_cur_t* cursor, mtr_t* mtr)
{
page_cur_t* page_cursor;
dict_tree_t* tree;
page_t* page;
ulint page_no;
ulint space;
ulint height;
ulint root_height;
rec_t* node_ptr;
ulint estimate;
ulint savepoint;
estimate = latch_mode & BTR_ESTIMATE;
latch_mode = latch_mode & ~BTR_ESTIMATE;
tree = index->tree;
savepoint = mtr_set_savepoint(mtr);
if(latch_mode == BTR_MODIFY_TREE)
mtr_x_lock(dict_tree_get_lock(tree), mtr);
else
mtr_s_lock(dict_tree_get_lock(tree), mtr);
page_cursor = btr_cur_get_page_cur(cursor);
cursor->index = index;
space = dict_tree_get_space(tree);
page_no = dict_tree_get_page(tree);
height = ULINT_UNDEFINED;
for(;;){
page = buf_page_get_gen(space, page_no, RW_NO_LATCH, NULL,
BUF_GET, __FILE__, __LINE__, mtr);
ut_ad(0 == ut_dulint_cmp(tree->id, btr_page_get_index_id(page)));
if(height == ULINT_UNDEFINED){
height = btr_page_get_level(page, mtr);
root_height = height;
}
if(height == 0){
btr_cur_latch_leaves(tree, page, space, page_no, latch_mode, cursor, mtr);
if(latch_mode != BTR_MODIFY_TREE && latch_mode != BTR_CONT_MODIFY_TREE)
mtr_release_s_latch_at_savepoint(mtr, savepoint, dict_tree_get_lock(tree));
}
if(from_left) /*从页第一条记录*/
page_cur_set_before_first(page, page_cursor);
else /*从页的最后一条记录开始*/
page_cur_set_after_last(page, page_cursor);
if(height == 0){
if(estimate)
btr_cur_add_path_info(cursor, height, root_height);
break;
}
ut_ad(height > 0);
if(from_left)
page_cur_move_to_next(page_cursor);
else
page_cur_move_to_prev(page_cursor);
if(estimate)
btr_cur_add_path_info(cursor, height, root_height);
height --;
node_ptr = page_cur_get_rec(page_cursor);
page_no = btr_node_ptr_get_child_page_no(node_ptr);
}
}
/*在btree index的管辖范围，随机定位到一个位置*/
void btr_cur_open_at_rnd_pos(dict_index_t* index, ulint latch_mode, btr_cur_t* cursor, mtr_t* mtr)
{
page_cur_t* page_cursor;
dict_tree_t* tree;
page_t* page;
ulint page_no;
ulint space;
ulint height;
rec_t* node_ptr;
tree = index->tree;
if(latch_mode == BTR_MODIFY_TREE)
mtr_x_lock(dict_tree_get_lock(tree), mtr);
else
mtr_s_lock(dict_tree_get_lock(tree), mtr);
page_cursor = btr_cur_get_page_cur(cursor);
cursor->index = index;
space = dict_tree_get_space(tree);
page_no = dict_tree_get_page(tree);
height = ULINT_UNDEFINED;
for(;;){
page = buf_page_get_gen(space, page_no, RW_NO_LATCH, NULL, BUF_GET, __FILE__, __LINE__, mtr);
ut_ad(0 == ut_dulint_cmp(tree->id, btr_page_get_index_id(page)));
if(height == ULINT_UNDEFINED)
height = btr_page_get_level(page, mtr);
if(height == 0)
btr_cur_latch_leaves(tree, page, space, page_no, latch_mode, cursor, mtr);
/*随机定位一条记录，并将page cursor指向它*/
page_cur_open_on_rnd_user_rec(page, page_cursor);
if(height == 0)
break;
ut_ad(height > 0);
height --;
node_ptr = page_cur_get_rec(page_cursor);
page_no = btr_node_ptr_get_child_page_no(node_ptr);
}
}
static rec_t* btr_cur_insert_if_possible(btr_cur_t* cursor, dtuple_t* tuple, ibool* reorg, mtr_t* mtr)
{
page_cur_t* page_cursor;
page_t* page;
rec_t* rec;
ut_ad(dtuple_check_typed(tuple));
*reorg = FALSE;
page = btr_cur_get_page(cursor);
ut_ad(mtr_memo_contains(mtr, buf_block_align(page), MTR_MEMO_PAGE_X_FIX));
page_cursor = btr_cur_get_page_cur(cursor);
/*将tuple插入到page中*/
rec = page_cur_tuple_insert(page_cursor, tuple, mtr);
if(rec == NULL){
/*可能空间不够或者排序不对，进行页重组,有可能插入记录的空间无法在page上分配(没有空闲的rec空间，删除的单条记录 < tuple所需要的空间)*/
btr_page_reorganize(page, mtr);
*reorg = TRUE;
/*重新定位page游标*/
page_cur_search(page, tuple, PAGE_CUR_GE, page_cursor);
rec = page_cur_tuple_insert(page_cursor, tuple, mtr);
}
return rec;
}
/*为插入的记录添加一个事务锁和回滚日志*/
UNIV_INLINE ulint btr_cur_ins_lock_and_undo(ulint flags, btr_cur_t* cursor, dtuple_t* entry, que_thr_t* thr, ibool* inherit)
{
dict_index_t* index;
ulint err;
rec_t* rec;
dulint roll_ptr;
rec = btr_cur_get_rec(cursor);
index = cursor->index;
/*添加一个事务锁，如果有对应的行锁，重复利用*/
err = lock_rec_insert_check_and_lock(flags, rec, index, thr, inherit);
if(err != DB_SUCCESS) /*添加锁失败*/
return err;
if(index->type & DICT_CLUSTERED && !(index->type & DICT_IBUF)){
err = trx_undo_report_row_operation(flags, TRX_UNDO_INSERT_OP, thr, index, entry,
NULL, 0, NULL, &roll_ptr);
if(err != DB_SUCCESS)
return err;
if(!(flags & BTR_KEEP_SYS_FLAG))
row_upd_index_entry_sys_field(entry, index, DATA_ROLL_PTR, roll_ptr);
}
return DB_SUCCESS;
}
/*尝试以乐观式插入记录*/
ulint btr_cur_optimistic_insert(ulint flags, btr_cur_t* cursor, dtuple_t* entry, rec_t** rec, big_rec_t** big_rec, que_thr_t* thr, mtr_t* mtr)
{
big_rec_t* big_rec_vec = NULL;
dict_index_t* index;
page_cur_t* page_cursor;
page_t* page;
ulint max_size;
rec_t* dummy_rec;
ulint level;
ibool reorg;
ibool inherit;
ulint rec_size;
ulint data_size;
ulint extra_size;
ulint type;
ulint err;
*big_rec = NULL;
page = btr_cur_get_page(cursor);
index = cursor->index;
if(!dtuple_check_typed_no_assert(entry))
fprintf(stderr, "InnoDB: Error in a tuple to insert into table %lu index %s\n",
index->table_name, index->name);
if (btr_cur_print_record_ops && thr) {
printf("Trx with id %lu %lu going to insert to table %s index %s\n",
ut_dulint_get_high(thr_get_trx(thr)->id),
ut_dulint_get_low(thr_get_trx(thr)->id),
index->table_name, index->name);
dtuple_print(entry);
}
ut_ad(mtr_memo_contains(mtr, buf_block_align(page), MTR_MEMO_PAGE_X_FIX));
/*page可以容纳的最大记录空间*/
max_size = page_get_max_insert_size_after_reorganize(page, 1);
level = btr_page_get_level(page, mtr); /*获得page所处的层*/
calculate_sizes_again:
/*获得tuple存储需要的空间大小*/
data_size = dtuple_get_data_size(entry);
/*获得rec header需要的长度*/
extra_size = rec_get_converted_extra_size(data_size, dtuple_get_n_fields(entry));
rec_size = data_size + extra_size;
/*记录超出最大的存储范围，将其转化为big_rec*/
if((rec_size >= page_get_free_space_of_empty() / 2) || rec_size >= REC_MAX_DATA_SIZE){
big_rec_vec = dtuple_convert_big_rec(index, entry, NULL, 0);
/*转化失败,记录实在太大,可能有太多的短列？*/
if(big_rec_vec == NULL)
return DB_TOO_BIG_RECORD;
goto calculate_sizes_again;
}
type = index->type;
/*聚集索引，在叶子节点可以进行左右分裂,而且BTREE树的空间不够？？不能存入，将转化为big_rec的操作回滚*/
if ((type & DICT_CLUSTERED)
&& (dict_tree_get_space_reserve(index->tree) + rec_size > max_size)
&& (page_get_n_recs(page) >= 2)
&& (0 == level)
&& (btr_page_get_split_rec_to_right(cursor, &dummy_rec)
|| btr_page_get_split_rec_to_left(cursor, &dummy_rec))){
if(big_rec_vec) /*将tuple转化成big_rec*/
dtuple_convert_back_big_rec(index, entry, big_rec_vec);
return DB_FAIL;
}
if (!(((max_size >= rec_size) && (max_size >= BTR_CUR_PAGE_REORGANIZE_LIMIT))
|| page_get_max_insert_size(page, 1) >= rec_size || page_get_n_recs(page) <= 1)) {
if(big_rec_vec)
dtuple_convert_back_big_rec(index, entry, big_rec_vec);
return DB_FAIL;
}
err = btr_cur_ins_lock_and_undo(flags, cursor, entry, thr, &inherit);
if(err != DB_SUCCESS){ /*事务加锁不成功，回滚big_rec*/
if(big_rec_vec)
dtuple_convert_back_big_rec(index, entry, big_rec_vec);
return err;
}
page_cursor = btr_cur_get_page_cur(cursor);
reorg = FALSE;
/*将tuple插入到page当中*/
*rec = page_cur_insert_rec_low(page_cursor, entry, data_size, NULL, mtr);
if(*rec == NULL){ /*插入失败，进行page重组*/
btr_page_reorganize(page, mtr);
ut_ad(page_get_max_insert_size(page, 1) == max_size);
reorg = TRUE;
page_cur_search(page, entry, PAGE_CUR_LE, page_cursor);
*rec = page_cur_tuple_insert(page_cursor, entry, mtr);
if(*rec == NULL){ /*重组后还是失败，打印错误信息*/
char* err_buf = mem_alloc(1000);
dtuple_sprintf(err_buf, 900, entry);
fprintf(stderr, "InnoDB: Error: cannot insert tuple %s to index %s of table %s\n"
"InnoDB: max insert size %lu\n", err_buf, index->name, index->table->name, max_size);
mem_free(err_buf);
}
ut_a(*rec);
}
/*更新HASH索引*/
if(!reorg && level == 0 && cursor->flag == BTR_CUR_HASH)
btr_search_update_hash_node_on_insert(cursor);
else
btr_search_update_hash_on_insert(cursor);
/*继承后一行事务锁(GAP方式)*/
if(!(flags & BTR_NO_LOCKING_FLAG) && inherit)
lock_update_insert(*rec);
/*非聚集索引插入*/
if(!(type & DICT_CLUSTERED))
ibuf_update_free_bits_if_full(cursor->index, page, max_size,
rec_size + PAGE_DIR_SLOT_SIZE);
*big_rec = big_rec_vec;
return DB_SUCCESS;
}
/*以悲观执行记录的插入,悲观方式是表空间不够，需要扩大表空间*/
ulint btr_cur_pessimistic_insert(ulint flags, btr_cur_t* cursor, dtuple_t* entry, rec_t** rec, big_rec_t** big_rec, que_thr_t* thr, mtr_t* mtr)
{
dict_index_t* index = cursor->index;
big_rec_t* big_rec_vec = NULL;
page_t* page;
ulint err;
ibool dummy_inh;
ibool success;
ulint n_extents = 0;
*big_rec = NULL;
page = btr_cur_get_page(cursor);
ut_ad(mtr_memo_contains(mtr, dict_tree_get_lock(btr_cur_get_tree(cursor)), MTR_MEMO_X_LOCK));
ut_ad(mtr_memo_contains(mtr, buf_block_align(page), MTR_MEMO_PAGE_X_FIX));
cursor->flag = BTR_CUR_BINARY;
err = btr_cur_optimistic_insert(flags, cursor, entry, rec, big_rec, thr, mtr);
if(err != DB_FAIL) /*乐观锁方式插入成功，直接返回*/
return err;
err = btr_cur_ins_lock_and_undo(flags, cursor, entry, thr, &dummy_inh);
if(err != DB_SUCCESS)
return err;
if(!(flags && BTR_NO_UNDO_LOG_FLAG)){
n_extents = cursor->tree_height / 16 + 3;
/*扩大file space表空间*/
success = fsp_reserve_free_extents(index->space, n_extents, FSP_NORMAL, mtr);
if(!success){ /*超出表空间范围*/
err = DB_OUT_OF_FILE_SPACE;
return err;
}
}
/*单个页无法存储entry记录,作为大记录存储*/
if(rec_get_converted_size(entry) >= page_get_free_space_of_empty() / 2 || rec_get_converted_size(entry) >= REC_MAX_DATA_SIZE){
big_rec_vec = dtuple_convert_big_rec(index, entry, NULL, 0);
if(big_rec_vec == NULL)
return DB_TOO_BIG_RECORD;
}
if (dict_tree_get_page(index->tree) == buf_frame_get_page_no(page))
*rec = btr_root_raise_and_insert(cursor, entry, mtr);
else
*rec = btr_page_split_and_insert(cursor, entry, mtr);
btr_cur_position(index, page_rec_get_prev(*rec), cursor);
/*更新自适应HASH*/
btr_search_update_hash_on_insert(cursor);
/*新插入行对gap行锁的继承*/
if(!(flags & BTR_NO_LOCKING_FLAG))
lock_update_insert(*rec);
err = DB_SUCCESS;
if(n_extents > 0)
fil_space_release_free_extents(index->space, n_extents);
*big_rec = big_rec_vec;
return err;
}
/*按聚集索引修改记录，进行事务锁请求*/
UNIV_INLINE ulint btr_cur_upd_lock_and_undo(ulint flags, btr_cur_t* cursor, upd_t* update, ulint cmpl_info, que_thr_t* thr, dulint roll_ptr)
{
dict_index_t* index;
rec_t* rec;
ulint err;
ut_ad(cursor && update && thr && roll_ptr);
ut_ad(cursor->index->type & DICT_CLUSTERED);
rec = btr_cur_get_rec(cursor);
index = cursor->index;
err =DB_SUCCESS;
if(!(flags & BTR_NO_LOCKING_FLAG)){
/*检查修改记录时，记录聚集索引上是否有锁（包括显式锁和隐式锁）*/
err = lock_clust_rec_modify_check_and_lock(flags, rec, index, thr);
if(err != DB_SUCCESS)
return err;
}
err = trx_undo_report_row_operation(flags, TRX_UNDO_MODIFY_OP, thr, index, NULL, update,
cmpl_info, rec, roll_ptr);
return err;
}
/*为update record增加一条redo log*/
UNIV_INLINE void btr_cur_update_in_place_log(ulint flags, rec_t* rec, dict_index_t* index,
upd_t* update, trx_t* trx, dulint roll_ptr, mtr_t* mtr)
{
byte* log_ptr;
log_ptr = mlog_open(mtr, 30 + MLOG_BUF_MARGIN);
log_ptr = mlog_write_initial_log_record_fast(rec, MLOG_REC_UPDATE_IN_PLACE, log_ptr, mtr);
mach_write_to_1(log_ptr, flags);
log_ptr++;
log_ptr = row_upd_write_sys_vals_to_log(index, trx, roll_ptr, log_ptr, mtr);
mach_write_to_2(log_ptr, rec - buf_frame_align(rec));
log_ptr += 2;
row_upd_index_write_log(update, log_ptr, mtr);
}
/*解析一条修改记录的redo log并进行重演*/
byte* btr_cur_parse_update_in_place(byte* ptr, byte* end_ptr, page_t* page, mtr_t* mtr)
{
ulint flags;
rec_t* rec;
upd_t* update;
ulint pos;
dulint trx_id;
dulint roll_ptr;
ulint rec_offset;
mem_heap_t* heap;
if(end_ptr < ptr + 1)
return NULL;
flags = mach_read_from_1(ptr);
ptr++;
ptr = row_upd_parse_sys_vals(ptr, end_ptr, &pos, &trx_id, &roll_ptr);
if(ptr == NULL)
return NULL;
if(end_ptr < ptr + 2)
return NULL;
/*从redo log中读取修改记录的偏移*/
rec_offset = mach_read_from_2(ptr);
ptr += 2;
/*从redo log中读取修改的内容*/
heap = mem_heap_create(256);
ptr = row_upd_index_parse(ptr, end_ptr, heap, &update);
if(ptr == NULL){
mem_heap_free(heap);
return NULL;
}
if(page == NULL){
mem_heap_free(heap);
return NULL;
}
rec = page + rec_offset;
if(!(flags & BTR_KEEP_SYS_FLAG))
row_upd_rec_sys_fields_in_recovery(rec, pos, trx_id, roll_ptr);
/*进行记录修改*/
row_upd_rec_in_place(heap, update);
mem_heap_free(heap);
return ptr;
}
/*通过辅助索引修改对应的记录*/
ulint btr_cur_update_sec_rec_in_place(btr_cur_t* cursor, upd_t* update, que_thr_t* thr, mtr_t* mtr)
{
dict_index_t* index = cursor->index;
dict_index_t* clust_index;
ulint err;
rec_t* rec;
dulint roll_ptr = ut_dulint_zero;
trx_t* trx = thr_get_trx(thr);
ut_ad(0 == (index->type & DICT_CLUSTERED));
rec = btr_cur_get_rec(cursor);
if(btr_cur_print_record_ops && thr){
printf("Trx with id %lu %lu going to update table %s index %s\n",
ut_dulint_get_high(thr_get_trx(thr)->id),ut_dulint_get_low(thr_get_trx(thr)->id), index->table_name, index->name);
rec_print(rec);
}
/*通过二级索引获得行上的锁*/
err = lock_sec_rec_modify_check_and_lock(0, rec, index, thr);
if(err != DB_SUCCESS)
return err;
/*删除自适应HASH对应关系*/
btr_search_update_hash_on_delete(cursor);
/*对记录进行修改*/
row_upd_rec_in_place(rec, update);
/*通过二级索引找到聚集索引*/
clust_index = dict_table_get_first_index(index->table);
/*通过聚集索引添加一条修改记录的redo log*/
btr_cur_update_in_place_log(BTR_KEEP_SYS_FLAG, rec, clust_index, update, trx, roll_ptr, mtr);
return DB_SUCCESS;
}
ulint btr_cur_update_in_place(ulint flags, btr_cur_t* cursor, upd_t* update, ulint cmpl_info, que_thr_t* thr, mtr_t* mtr)
{
dict_index_t* index;
buf_block_t* block;
ulint err;
rec_t* rec;
dulint roll_ptr;
trx_t* trx;
ibool was_delete_marked;
ut_ad(cursor->index->type & DICT_CLUSTERED);
/*获得对应的记录、索引、事务*/
rec = btr_cur_get_rec(cursor);
index = cursor->index;
trx = thr_get_trx(thr);
if(btr_cur_print_record_ops && thr){
printf("Trx with id %lu %lu going to update table %s index %s\n",
ut_dulint_get_high(thr_get_trx(thr)->id),
ut_dulint_get_low(thr_get_trx(thr)->id),
index->table_name, index->name);
rec_print(rec);
}
/*获得事务的行锁*/
err = btr_cur_upd_lock_and_undo(flags, cursor, update, cmpl_info, thr, &roll_ptr);
if(err != DB_SUCCESS)
return err;
block = buf_block_align(rec);
if(block->is_hashed){
if (row_upd_changes_ord_field_binary(NULL, index, update))
btr_search_update_hash_on_delete(cursor);
rw_lock_x_lock(&btr_search_latch);
}
if(!(flags & BTR_KEEP_SYS_FLAG))
row_upd_rec_sys_fields(rec, index, trx, roll_ptr);
was_delete_marked = rec_get_deleted_flag(rec);
/*进行记录更新*/
row_upd_rec_in_place(rec, update);
if(block->is_hashed)
rw_lock_x_unlock(&btr_search_latch);
btr_cur_update_in_place_log(flags, rec, index, update, trx, roll_ptr, mtr);
/*由删除状态变成未删除状态*/
if(was_delete_marked && !rec_get_deleted_flag(rec))
btr_cur_unmark_extern_fields(rec, mtr);
return DB_SUCCESS;
}
/*乐观方式更新一条记录，先尝试在原来的记录位置直接更新，如果不能就会将原来的记录删除，将更新的内容组成一条记录插入到对应的page中*/
ulint btr_cur_optimistic_update(ulint flags, btr_cur_t* cursor, upd_t* update, ulint cmpl_info, que_thr_t* thr, mtr_t* mtr)
{
dict_index_t* index;
page_cur_t* page_cursor;
ulint err;
page_t* page;
rec_t* rec;
ulint max_size;
ulint new_rec_size;
ulint old_rec_size;
dtuple_t* new_entry;
dulint roll_ptr;
trx_t* trx;
mem_heap_t* heap;
ibool reorganized = FALSE;
ulint i;
ut_ad((cursor->index)->type & DICT_CLUSTERED);
page = btr_cur_get_page(cursor);
rec = btr_cur_get_rec(cursor);
index = cursor->index;
if (btr_cur_print_record_ops && thr) {
printf("Trx with id %lu %lu going to update table %s index %s\n",
ut_dulint_get_high(thr_get_trx(thr)->id),
ut_dulint_get_low(thr_get_trx(thr)->id),
index->table_name, index->name);
rec_print(rec);
}
ut_ad(mtr_memo_contains(mtr, buf_block_align(page), MTR_MEMO_BUF_FIX));
/*不能改变列的大小，直接在原来的记录位置做更新*/
if(!row_upd_changes_field_size(rec, index, update))
return btr_cur_update_in_place(flags, cursor, update, cmpl_info, thr, mtr);
/*判断列是否溢出*/
for(i = 0; i < upd_get_n_fields(update); i++){
if(upd_get_nth_field(update, i)->extern_storage)
return DB_OVERFLOW;
}
/*列已是两个字节表示长度*/
if(rec_contains_externally_stored_field(btr_cur_get_rec(cursor)))
return DB_OVERFLOW;
page_cursor = btr_cur_get_page_cur(cursor);
heap = mem_heap_create(1024);
/*在内存中构建一个新记录的存储对象记录*/
new_entry = row_rec_to_index_entry(ROW_COPY_DATA, index, rec, heap);
row_upd_clust_index_replace_new_col_vals(new_entry, update);
old_rec_size = rec_get_size(rec);
new_rec_size = rec_get_converted_size(new_entry);
/*跟新的记录大小已经超过页能存储的大小*/
if(new_rec_size >= page_get_free_space_of_empty() / 2){
mem_heap_free(heap);
return DB_OVERFLOW;
}
/*计算页重组后可以存储的最大空间*/
max_size = old_rec_size + page_get_max_insert_size_after_reorganize(page, 1);
if(page_get_data_size(page) - old_rec_size + new_rec_size < BTR_CUR_PAGE_COMPRESS_LIMIT){
/*记录更新后会触发btree的合并填充，不做直接更新*/
mem_heap_free(heap);
return DB_UNDERFLOW;
}
/*能存储的空间小于合并的空间阈值或者不能存下新的记录,并且page的空间不只1条记录*/
if(!((max_size >= BTR_CUR_PAGE_REORGANIZE_LIMIT && max_size >= new_rec_size) || page_get_n_recs(page) <= 1)){
mem_heap_free(heap);
return DB_OVERFLOW;
}
/*不能对记录加事务锁*/
err = btr_cur_upd_lock_and_undo(flags, cursor, update, cmpl_info, thr, &roll_ptr);
if(err != DB_SUCCESS){
mem_heap_free(heap);
return err;
}
/*将记录的行锁全部转移到infimum,应该是临时存储在这个地方*/
lock_rec_store_on_page_infimum(rec);
btr_search_update_hash_on_delete(cursor);
/*将page游标对应的记录删除*/
page_cur_delete_rec(page_cursor, mtr);
/*游标移到前面一条记录上*/
page_cur_move_to_prev(page_cursor);
trx = thr_get_trx(thr);
if(!(flags & BTR_KEEP_SYS_FLAG)){
row_upd_index_entry_sys_field(new_entry, index, DATA_ROLL_PTR, roll_ptr);
row_upd_index_entry_sys_field(new_entry, index, DATA_TRX_ID, trx->id);
}
/*将新构建的tuple记录插入到页中*/
rec = btr_cur_insert_if_possible(cursor, new_entry, &reorganized, mtr);
ut_a(rec);
if(!rec_get_deleted_flag(rec))
btr_cur_unmark_extern_fields(rec, mtr);
/*将缓存在infimum上的锁恢复到新插入的记录上*/
lock_rec_restore_from_page_infimum(rec, page);
page_cur_move_to_next(page_cursor);
mem_heap_free(heap);
return DB_SUCCESS;
}
static void btr_cur_pess_upd_restore_supremum(rec_t* rec, mtr_t* mtr)
{
page_t* page;
page_t* prev_page;
ulint space;
ulint prev_page_no;
page = buf_frame_align(rec);
if(page_rec_get_next(page_get_infimum_rec(page) != rec))
return;
/*获得rec前一页的page对象*/
space = buf_frame_get_space_id(page);
prev_page_no = btr_page_get_prev(page, mtr);
ut_ad(prev_page_no != FIL_NULL);
prev_page = buf_page_get_with_no_latch(space, prev_page_no, mtr);
/*确定已经拥有x-latch*/
ut_ad(mtr_memo_contains(mtr, buf_block_align(prev_page), MTR_MEMO_PAGE_X_FIX));
/*前一个page的supremum继承rec上的锁*/
lock_rec_reset_and_inherit_gap_locks(page_get_supremum_rec(prev_page), rec);
}