My favorites | Sign in
go
Project Home Downloads Wiki Issues Source Code Search
Repository:
Checkout   Browse   Changes   Clones  
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
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

#include "runtime.h"
#include "hashmap.h"
#include "type.h"

/* Return a pointer to the struct/union of type "type"
whose "field" field is addressed by pointer "p". */

struct Hmap { /* a hash table; initialize with hash_init() */
uint32 count; /* elements in table - must be first */

uint8 datasize; /* amount of data to store in entry */
uint8 max_power; /* max power of 2 to create sub-tables */
uint8 max_probes; /* max entries to probe before rehashing */
uint8 indirectval; /* storing pointers to values */
int32 changes; /* inc'ed whenever a subtable is created/grown */
hash_hash_t (*data_hash) (uint32, void *a); /* return hash of *a */
uint32 (*data_eq) (uint32, void *a, void *b); /* return whether *a == *b */
void (*data_del) (uint32, void *arg, void *data); /* invoked on deletion */
struct hash_subtable *st; /* first-level table */

uint32 keysize;
uint32 valsize;
uint32 datavo;

// three sets of offsets: the digit counts how many
// of key, value are passed as inputs:
// 0 = func() (key, value)
// 1 = func(key) (value)
// 2 = func(key, value)
uint32 ko0;
uint32 vo0;
uint32 ko1;
uint32 vo1;
uint32 po1;
uint32 ko2;
uint32 vo2;
uint32 po2;
Alg* keyalg;
Alg* valalg;
};

struct hash_entry {
hash_hash_t hash; /* hash value of data */
byte data[1]; /* user data has "datasize" bytes */
};

struct hash_subtable {
uint8 power; /* bits used to index this table */
uint8 used; /* bits in hash used before reaching this table */
uint8 datasize; /* bytes of client data in an entry */
uint8 max_probes; /* max number of probes when searching */
int16 limit_bytes; /* max_probes * (datasize+sizeof (hash_hash_t)) */
struct hash_entry *last; /* points to last element of entry[] */
struct hash_entry entry[1]; /* 2**power+max_probes-1 elements of elemsize bytes */
};

#define HASH_DATA_EQ(h,x,y) ((*h->data_eq) (h->keysize, (x), (y)))

#define HASH_REHASH 0x2 /* an internal flag */
/* the number of bits used is stored in the flags word too */
#define HASH_USED(x) ((x) >> 2)
#define HASH_MAKE_USED(x) ((x) << 2)

#define HASH_LOW 6
#define HASH_ONE (((hash_hash_t)1) << HASH_LOW)
#define HASH_MASK (HASH_ONE - 1)
#define HASH_ADJUST(x) (((x) < HASH_ONE) << HASH_LOW)

#define HASH_BITS (sizeof (hash_hash_t) * 8)

#define HASH_SUBHASH HASH_MASK
#define HASH_NIL 0
#define HASH_NIL_MEMSET 0

#define HASH_OFFSET(base, byte_offset) \
((struct hash_entry *) (((byte *) (base)) + (byte_offset)))


/* return a hash layer with 2**power empty entries */
static struct hash_subtable *
hash_subtable_new (Hmap *h, int32 power, int32 used)
{
int32 elemsize = h->datasize + offsetof (struct hash_entry, data[0]);
int32 bytes = elemsize << power;
struct hash_subtable *st;
int32 limit_bytes = h->max_probes * elemsize;
int32 max_probes = h->max_probes;

if (bytes < limit_bytes) {
limit_bytes = bytes;
max_probes = 1 << power;
}
bytes += limit_bytes - elemsize;
st = malloc (offsetof (struct hash_subtable, entry[0]) + bytes);
st->power = power;
st->used = used;
st->datasize = h->datasize;
st->max_probes = max_probes;
st->limit_bytes = limit_bytes;
st->last = HASH_OFFSET (st->entry, bytes) - 1;
memset (st->entry, HASH_NIL_MEMSET, bytes);
return (st);
}

static void
init_sizes (int64 hint, int32 *init_power, int32 *max_power)
{
int32 log = 0;
int32 i;

for (i = 32; i != 0; i >>= 1) {
if ((hint >> (log + i)) != 0) {
log += i;
}
}
log += 1 + (((hint << 3) >> log) >= 11); /* round up for utilization */
if (log <= 14) {
*init_power = log;
} else {
*init_power = 12;
}
*max_power = 12;
}

static void
hash_init (Hmap *h,
int32 datasize,
hash_hash_t (*data_hash) (uint32, void *),
uint32 (*data_eq) (uint32, void *, void *),
void (*data_del) (uint32, void *, void *),
int64 hint)
{
int32 init_power;
int32 max_power;

if(datasize < sizeof (void *))
datasize = sizeof (void *);
datasize = runtime·rnd(datasize, sizeof (void *));
init_sizes (hint, &init_power, &max_power);
h->datasize = datasize;
h->max_power = max_power;
h->max_probes = 15;
assert (h->datasize == datasize);
assert (h->max_power == max_power);
assert (sizeof (void *) <= h->datasize || h->max_power == 255);
h->count = 0;
h->changes = 0;
h->data_hash = data_hash;
h->data_eq = data_eq;
h->data_del = data_del;
h->st = hash_subtable_new (h, init_power, 0);
}

static void
hash_remove_n (struct hash_subtable *st, struct hash_entry *dst_e, int32 n)
{
int32 elemsize = st->datasize + offsetof (struct hash_entry, data[0]);
struct hash_entry *src_e = HASH_OFFSET (dst_e, n * elemsize);
struct hash_entry *last_e = st->last;
int32 shift = HASH_BITS - (st->power + st->used);
int32 index_mask = (((hash_hash_t)1) << st->power) - 1;
int32 dst_i = (((byte *) dst_e) - ((byte *) st->entry)) / elemsize;
int32 src_i = dst_i + n;
hash_hash_t hash;
int32 skip;
int32 bytes;

while (dst_e != src_e) {
if (src_e <= last_e) {
struct hash_entry *cp_e = src_e;
int32 save_dst_i = dst_i;
while (cp_e <= last_e && (hash = cp_e->hash) != HASH_NIL &&
((hash >> shift) & index_mask) <= dst_i) {
cp_e = HASH_OFFSET (cp_e, elemsize);
dst_i++;
}
bytes = ((byte *) cp_e) - (byte *) src_e;
memmove (dst_e, src_e, bytes);
dst_e = HASH_OFFSET (dst_e, bytes);
src_e = cp_e;
src_i += dst_i - save_dst_i;
if (src_e <= last_e && (hash = src_e->hash) != HASH_NIL) {
skip = ((hash >> shift) & index_mask) - dst_i;
} else {
skip = src_i - dst_i;
}
} else {
skip = src_i - dst_i;
}
bytes = skip * elemsize;
memset (dst_e, HASH_NIL_MEMSET, bytes);
dst_e = HASH_OFFSET (dst_e, bytes);
dst_i += skip;
}
}

static int32
hash_insert_internal (struct hash_subtable **pst, int32 flags, hash_hash_t hash,
Hmap *h, void *data, void **pres);

static void
hash_conv (Hmap *h,
struct hash_subtable *st, int32 flags,
hash_hash_t hash,
struct hash_entry *e)
{
int32 new_flags = (flags + HASH_MAKE_USED (st->power)) | HASH_REHASH;
int32 shift = HASH_BITS - HASH_USED (new_flags);
hash_hash_t prefix_mask = (-(hash_hash_t)1) << shift;
int32 elemsize = h->datasize + offsetof (struct hash_entry, data[0]);
void *dummy_result;
struct hash_entry *de;
int32 index_mask = (1 << st->power) - 1;
hash_hash_t e_hash;
struct hash_entry *pe = HASH_OFFSET (e, -elemsize);

while (e != st->entry && (e_hash = pe->hash) != HASH_NIL && (e_hash & HASH_MASK) != HASH_SUBHASH) {
e = pe;
pe = HASH_OFFSET (pe, -elemsize);
}

de = e;
while (e <= st->last &&
(e_hash = e->hash) != HASH_NIL &&
(e_hash & HASH_MASK) != HASH_SUBHASH) {
struct hash_entry *target_e = HASH_OFFSET (st->entry, ((e_hash >> shift) & index_mask) * elemsize);
struct hash_entry *ne = HASH_OFFSET (e, elemsize);
hash_hash_t current = e_hash & prefix_mask;
if (de < target_e) {
memset (de, HASH_NIL_MEMSET, ((byte *) target_e) - (byte *) de);
de = target_e;
}
if ((hash & prefix_mask) == current ||
(ne <= st->last && (e_hash = ne->hash) != HASH_NIL &&
(e_hash & prefix_mask) == current)) {
struct hash_subtable *new_st = hash_subtable_new (h, 1, HASH_USED (new_flags));
int32 rc = hash_insert_internal (&new_st, new_flags, e->hash, h, e->data, &dummy_result);
assert (rc == 0);
memcpy(dummy_result, e->data, h->datasize);
e = ne;
while (e <= st->last && (e_hash = e->hash) != HASH_NIL && (e_hash & prefix_mask) == current) {
assert ((e_hash & HASH_MASK) != HASH_SUBHASH);
rc = hash_insert_internal (&new_st, new_flags, e_hash, h, e->data, &dummy_result);
assert (rc == 0);
memcpy(dummy_result, e->data, h->datasize);
e = HASH_OFFSET (e, elemsize);
}
memset (de->data, HASH_NIL_MEMSET, h->datasize);
*(struct hash_subtable **)de->data = new_st;
de->hash = current | HASH_SUBHASH;
} else {
if (e != de) {
memcpy (de, e, elemsize);
}
e = HASH_OFFSET (e, elemsize);
}
de = HASH_OFFSET (de, elemsize);
}
if (e != de) {
hash_remove_n (st, de, (((byte *) e) - (byte *) de) / elemsize);
}
}

static void
hash_grow (Hmap *h, struct hash_subtable **pst, int32 flags)
{
struct hash_subtable *old_st = *pst;
int32 elemsize = h->datasize + offsetof (struct hash_entry, data[0]);
*pst = hash_subtable_new (h, old_st->power + 1, HASH_USED (flags));
struct hash_entry *last_e = old_st->last;
struct hash_entry *e;
void *dummy_result;
int32 used = 0;

flags |= HASH_REHASH;
for (e = old_st->entry; e <= last_e; e = HASH_OFFSET (e, elemsize)) {
hash_hash_t hash = e->hash;
if (hash != HASH_NIL) {
int32 rc = hash_insert_internal (pst, flags, e->hash, h, e->data, &dummy_result);
assert (rc == 0);
memcpy(dummy_result, e->data, h->datasize);
used++;
}
}
free (old_st);
}

static int32
hash_lookup (Hmap *h, void *data, void **pres)
{
int32 elemsize = h->datasize + offsetof (struct hash_entry, data[0]);
hash_hash_t hash = (*h->data_hash) (h->keysize, data) & ~HASH_MASK;
struct hash_subtable *st = h->st;
int32 used = 0;
hash_hash_t e_hash;
struct hash_entry *e;
struct hash_entry *end_e;

hash += HASH_ADJUST (hash);
for (;;) {
int32 shift = HASH_BITS - (st->power + used);
int32 index_mask = (1 << st->power) - 1;
int32 i = (hash >> shift) & index_mask; /* i is the natural position of hash */

e = HASH_OFFSET (st->entry, i * elemsize); /* e points to element i */
e_hash = e->hash;
if ((e_hash & HASH_MASK) != HASH_SUBHASH) { /* a subtable */
break;
}
used += st->power;
st = *(struct hash_subtable **)e->data;
}
end_e = HASH_OFFSET (e, st->limit_bytes);
while (e != end_e && (e_hash = e->hash) != HASH_NIL && e_hash < hash) {
e = HASH_OFFSET (e, elemsize);
}
while (e != end_e && ((e_hash = e->hash) ^ hash) < HASH_SUBHASH) {
if (HASH_DATA_EQ (h, data, e->data)) { /* a match */
*pres = e->data;
return (1);
}
e = HASH_OFFSET (e, elemsize);
}
USED(e_hash);
*pres = 0;
return (0);
}

static int32
hash_remove (Hmap *h, void *data, void *arg)
{
int32 elemsize = h->datasize + offsetof (struct hash_entry, data[0]);
hash_hash_t hash = (*h->data_hash) (h->keysize, data) & ~HASH_MASK;
struct hash_subtable *st = h->st;
int32 used = 0;
hash_hash_t e_hash;
struct hash_entry *e;
struct hash_entry *end_e;

hash += HASH_ADJUST (hash);
for (;;) {
int32 shift = HASH_BITS - (st->power + used);
int32 index_mask = (1 << st->power) - 1;
int32 i = (hash >> shift) & index_mask; /* i is the natural position of hash */

e = HASH_OFFSET (st->entry, i * elemsize); /* e points to element i */
e_hash = e->hash;
if ((e_hash & HASH_MASK) != HASH_SUBHASH) { /* a subtable */
break;
}
used += st->power;
st = *(struct hash_subtable **)e->data;
}
end_e = HASH_OFFSET (e, st->limit_bytes);
while (e != end_e && (e_hash = e->hash) != HASH_NIL && e_hash < hash) {
e = HASH_OFFSET (e, elemsize);
}
while (e != end_e && ((e_hash = e->hash) ^ hash) < HASH_SUBHASH) {
if (HASH_DATA_EQ (h, data, e->data)) { /* a match */
(*h->data_del) (h->datavo, arg, e->data);
hash_remove_n (st, e, 1);
h->count--;
return (1);
}
e = HASH_OFFSET (e, elemsize);
}
USED(e_hash);
return (0);
}

static int32
hash_insert_internal (struct hash_subtable **pst, int32 flags, hash_hash_t hash,
Hmap *h, void *data, void **pres)
{
int32 elemsize = h->datasize + offsetof (struct hash_entry, data[0]);

if ((flags & HASH_REHASH) == 0) {
hash += HASH_ADJUST (hash);
hash &= ~HASH_MASK;
}
for (;;) {
struct hash_subtable *st = *pst;
int32 shift = HASH_BITS - (st->power + HASH_USED (flags));
int32 index_mask = (1 << st->power) - 1;
int32 i = (hash >> shift) & index_mask; /* i is the natural position of hash */
struct hash_entry *start_e =
HASH_OFFSET (st->entry, i * elemsize); /* start_e is the pointer to element i */
struct hash_entry *e = start_e; /* e is going to range over [start_e, end_e) */
struct hash_entry *end_e;
hash_hash_t e_hash = e->hash;

if ((e_hash & HASH_MASK) == HASH_SUBHASH) { /* a subtable */
pst = (struct hash_subtable **) e->data;
flags += HASH_MAKE_USED (st->power);
continue;
}
end_e = HASH_OFFSET (start_e, st->limit_bytes);
while (e != end_e && (e_hash = e->hash) != HASH_NIL && e_hash < hash) {
e = HASH_OFFSET (e, elemsize);
i++;
}
if (e != end_e && e_hash != HASH_NIL) {
/* ins_e ranges over the elements that may match */
struct hash_entry *ins_e = e;
int32 ins_i = i;
hash_hash_t ins_e_hash;
while (ins_e != end_e && ((e_hash = ins_e->hash) ^ hash) < HASH_SUBHASH) {
if (HASH_DATA_EQ (h, data, ins_e->data)) { /* a match */
*pres = ins_e->data;
return (1);
}
assert (e_hash != hash || (flags & HASH_REHASH) == 0);
hash += (e_hash == hash); /* adjust hash if it collides */
ins_e = HASH_OFFSET (ins_e, elemsize);
ins_i++;
if (e_hash <= hash) { /* set e to insertion point */
e = ins_e;
i = ins_i;
}
}
/* set ins_e to the insertion point for the new element */
ins_e = e;
ins_i = i;
ins_e_hash = 0;
/* move ins_e to point at the end of the contiguous block, but
stop if any element can't be moved by one up */
while (ins_e <= st->last && (ins_e_hash = ins_e->hash) != HASH_NIL &&
ins_i + 1 - ((ins_e_hash >> shift) & index_mask) < st->max_probes &&
(ins_e_hash & HASH_MASK) != HASH_SUBHASH) {
ins_e = HASH_OFFSET (ins_e, elemsize);
ins_i++;
}
if (e == end_e || ins_e > st->last || ins_e_hash != HASH_NIL) {
e = end_e; /* can't insert; must grow or convert to subtable */
} else { /* make space for element */
memmove (HASH_OFFSET (e, elemsize), e, ((byte *) ins_e) - (byte *) e);
}
}
if (e != end_e) {
e->hash = hash;
*pres = e->data;
return (0);
}
h->changes++;
if (st->power < h->max_power) {
hash_grow (h, pst, flags);
} else {
hash_conv (h, st, flags, hash, start_e);
}
}
}

static int32
hash_insert (Hmap *h, void *data, void **pres)
{
int32 rc = hash_insert_internal (&h->st, 0, (*h->data_hash) (h->keysize, data), h, data, pres);

h->count += (rc == 0); /* increment count if element didn't previously exist */
return (rc);
}

static uint32
hash_count (Hmap *h)
{
return (h->count);
}

static void
iter_restart (struct hash_iter *it, struct hash_subtable *st, int32 used)
{
int32 elemsize = it->elemsize;
hash_hash_t last_hash = it->last_hash;
struct hash_entry *e;
hash_hash_t e_hash;
struct hash_iter_sub *sub = &it->subtable_state[it->i];
struct hash_entry *last;

for (;;) {
int32 shift = HASH_BITS - (st->power + used);
int32 index_mask = (1 << st->power) - 1;
int32 i = (last_hash >> shift) & index_mask;

last = st->last;
e = HASH_OFFSET (st->entry, i * elemsize);
sub->start = st->entry;
sub->last = last;

if ((e->hash & HASH_MASK) != HASH_SUBHASH) {
break;
}
sub->e = HASH_OFFSET (e, elemsize);
sub = &it->subtable_state[++(it->i)];
used += st->power;
st = *(struct hash_subtable **)e->data;
}
while (e <= last && ((e_hash = e->hash) == HASH_NIL || e_hash <= last_hash)) {
e = HASH_OFFSET (e, elemsize);
}
sub->e = e;
}

static void *
hash_next (struct hash_iter *it)
{
int32 elemsize = it->elemsize;
struct hash_iter_sub *sub = &it->subtable_state[it->i];
struct hash_entry *e = sub->e;
struct hash_entry *last = sub->last;
hash_hash_t e_hash = 0;

if (it->changes != it->h->changes) { /* hash table's structure changed; recompute */
it->changes = it->h->changes;
it->i = 0;
iter_restart (it, it->h->st, 0);
sub = &it->subtable_state[it->i];
e = sub->e;
last = sub->last;
}
if (e != sub->start && it->last_hash != HASH_OFFSET (e, -elemsize)->hash) {
struct hash_entry *start = HASH_OFFSET (e, -(elemsize * it->h->max_probes));
struct hash_entry *pe = HASH_OFFSET (e, -elemsize);
hash_hash_t last_hash = it->last_hash;
if (start < sub->start) {
start = sub->start;
}
while (e != start && ((e_hash = pe->hash) == HASH_NIL || last_hash < e_hash)) {
e = pe;
pe = HASH_OFFSET (pe, -elemsize);
}
while (e <= last && ((e_hash = e->hash) == HASH_NIL || e_hash <= last_hash)) {
e = HASH_OFFSET (e, elemsize);
}
}

for (;;) {
while (e <= last && (e_hash = e->hash) == HASH_NIL) {
e = HASH_OFFSET (e, elemsize);
}
if (e > last) {
if (it->i == 0) {
it->last_hash = HASH_OFFSET (e, -elemsize)->hash;
sub->e = e;
return (0);
} else {
it->i--;
sub = &it->subtable_state[it->i];
e = sub->e;
last = sub->last;
}
} else if ((e_hash & HASH_MASK) != HASH_SUBHASH) {
it->last_hash = e->hash;
sub->e = HASH_OFFSET (e, elemsize);
return (e->data);
} else {
struct hash_subtable *st =
*(struct hash_subtable **)e->data;
sub->e = HASH_OFFSET (e, elemsize);
it->i++;
assert (it->i < sizeof (it->subtable_state) /
sizeof (it->subtable_state[0]));
sub = &it->subtable_state[it->i];
sub->e = e = st->entry;
sub->start = st->entry;
sub->last = last = st->last;
}
}
}

static void
hash_iter_init (Hmap *h, struct hash_iter *it)
{
it->elemsize = h->datasize + offsetof (struct hash_entry, data[0]);
it->changes = h->changes;
it->i = 0;
it->h = h;
it->last_hash = 0;
it->subtable_state[0].e = h->st->entry;
it->subtable_state[0].start = h->st->entry;
it->subtable_state[0].last = h->st->last;
}

static void
clean_st (struct hash_subtable *st, int32 *slots, int32 *used)
{
int32 elemsize = st->datasize + offsetof (struct hash_entry, data[0]);
struct hash_entry *e = st->entry;
struct hash_entry *last = st->last;
int32 lslots = (((byte *) (last+1)) - (byte *) e) / elemsize;
int32 lused = 0;

while (e <= last) {
hash_hash_t hash = e->hash;
if ((hash & HASH_MASK) == HASH_SUBHASH) {
clean_st (*(struct hash_subtable **)e->data, slots, used);
} else {
lused += (hash != HASH_NIL);
}
e = HASH_OFFSET (e, elemsize);
}
free (st);
*slots += lslots;
*used += lused;
}

static void
hash_destroy (Hmap *h)
{
int32 slots = 0;
int32 used = 0;

clean_st (h->st, &slots, &used);
free (h);
}

static void
hash_visit_internal (struct hash_subtable *st,
int32 used, int32 level,
void (*data_visit) (void *arg, int32 level, void *data),
void *arg)
{
int32 elemsize = st->datasize + offsetof (struct hash_entry, data[0]);
struct hash_entry *e = st->entry;
int32 shift = HASH_BITS - (used + st->power);
int32 i = 0;

while (e <= st->last) {
int32 index = ((e->hash >> (shift - 1)) >> 1) & ((1 << st->power) - 1);
if ((e->hash & HASH_MASK) == HASH_SUBHASH) {
(*data_visit) (arg, level, e->data);
hash_visit_internal (*(struct hash_subtable **)e->data,
used + st->power, level + 1, data_visit, arg);
} else {
(*data_visit) (arg, level, e->data);
}
if (e->hash != HASH_NIL) {
assert (i < index + st->max_probes);
assert (index <= i);
}
e = HASH_OFFSET (e, elemsize);
i++;
}
}

static void
hash_visit (Hmap *h, void (*data_visit) (void *arg, int32 level, void *data), void *arg)
{
hash_visit_internal (h->st, 0, 0, data_visit, arg);
}

//
/// interfaces to go runtime
//

// hash requires < 256 bytes of data (key+value) stored inline.
// Only basic types can be key - biggest is complex128 (16 bytes).
// Leave some room to grow, just in case.
enum {
MaxValsize = 256 - 64
};

static void
donothing(uint32 s, void *a, void *b)
{
USED(s);
USED(a);
USED(b);
}

static void
freedata(uint32 datavo, void *a, void *b)
{
void *p;

USED(a);
p = *(void**)((byte*)b + datavo);
free(p);
}

static void**
hash_indirect(Hmap *h, void *p)
{
if(h->indirectval)
p = *(void**)p;
return p;
}

static int32 debug = 0;

// makemap(typ *Type, hint uint32) (hmap *map[any]any);
Hmap*
runtime·makemap_c(MapType *typ, int64 hint)
{
Hmap *h;
int32 keyalg, valalg, keysize, valsize, valsize_in_hash;
void (*data_del)(uint32, void*, void*);
Type *key, *val;

key = typ->key;
val = typ->elem;

if(hint < 0 || (int32)hint != hint)
runtime·panicstring("makemap: size out of range");

keyalg = key->alg;
valalg = val->alg;
keysize = key->size;
valsize = val->size;

if(keyalg >= nelem(runtime·algarray) || runtime·algarray[keyalg].hash == runtime·nohash) {
runtime·printf("map(keyalg=%d)\n", keyalg);
runtime·throw("runtime.makemap: unsupported map key type");
}

if(valalg >= nelem(runtime·algarray)) {
runtime·printf("map(valalg=%d)\n", valalg);
runtime·throw("runtime.makemap: unsupported map value type");
}

h = runtime·mal(sizeof(*h));

valsize_in_hash = valsize;
data_del = donothing;
if (valsize > MaxValsize) {
h->indirectval = 1;
data_del = freedata;
valsize_in_hash = sizeof(void*);
}

// align value inside data so that mark-sweep gc can find it.
// might remove in the future and just assume datavo == keysize.
h->datavo = keysize;
if(valsize_in_hash >= sizeof(void*))
h->datavo = runtime·rnd(keysize, sizeof(void*));

hash_init(h, h->datavo+valsize_in_hash,
runtime·algarray[keyalg].hash,
runtime·algarray[keyalg].equal,
data_del,
hint);

h->keysize = keysize;
h->valsize = valsize;
h->keyalg = &runtime·algarray[keyalg];
h->valalg = &runtime·algarray[valalg];

// these calculations are compiler dependent.
// figure out offsets of map call arguments.

// func() (key, val)
h->ko0 = runtime·rnd(sizeof(h), Structrnd);
h->vo0 = runtime·rnd(h->ko0+keysize, val->align);

// func(key) (val[, pres])
h->ko1 = runtime·rnd(sizeof(h), key->align);
h->vo1 = runtime·rnd(h->ko1+keysize, Structrnd);
h->po1 = h->vo1 + valsize;

// func(key, val[, pres])
h->ko2 = runtime·rnd(sizeof(h), key->align);
h->vo2 = runtime·rnd(h->ko2+keysize, val->align);
h->po2 = h->vo2 + valsize;

if(debug) {
runtime·printf("makemap: map=%p; keysize=%d; valsize=%d; keyalg=%d; valalg=%d; offsets=%d,%d; %d,%d,%d; %d,%d,%d\n",
h, keysize, valsize, keyalg, valalg, h->ko0, h->vo0, h->ko1, h->vo1, h->po1, h->ko2, h->vo2, h->po2);
}

return h;
}

// makemap(key, val *Type, hint int64) (hmap *map[any]any);
void
runtime·makemap(MapType *typ, int64 hint, Hmap *ret)
{
ret = runtime·makemap_c(typ, hint);
FLUSH(&ret);
}

// For reflect:
// func makemap(Type *mapType) (hmap *map)
void
reflect·makemap(MapType *t, Hmap *ret)
{
ret = runtime·makemap_c(t, 0);
FLUSH(&ret);
}

void
runtime·mapaccess(MapType *t, Hmap *h, byte *ak, byte *av, bool *pres)
{
byte *res;
Type *elem;

if(h == nil) {
elem = t->elem;
runtime·algarray[elem->alg].copy(elem->size, av, nil);
*pres = false;
return;
}

if(runtime·gcwaiting)
runtime·gosched();

res = nil;
if(hash_lookup(h, ak, (void**)&res)) {
*pres = true;
h->valalg->copy(h->valsize, av, hash_indirect(h, res+h->datavo));
} else {
*pres = false;
h->valalg->copy(h->valsize, av, nil);
}
}

// mapaccess1(hmap *map[any]any, key any) (val any);
#pragma textflag 7
void
runtime·mapaccess1(MapType *t, Hmap *h, ...)
{
byte *ak, *av;
bool pres;

if(h == nil) {
ak = (byte*)(&h + 1);
av = ak + runtime·rnd(t->key->size, Structrnd);
} else {
ak = (byte*)&h + h->ko1;
av = (byte*)&h + h->vo1;
}

runtime·mapaccess(t, h, ak, av, &pres);

if(debug) {
runtime·prints("runtime.mapaccess1: map=");
runtime·printpointer(h);
runtime·prints("; key=");
h->keyalg->print(h->keysize, ak);
runtime·prints("; val=");
h->valalg->print(h->valsize, av);
runtime·prints("; pres=");
runtime·printbool(pres);
runtime·prints("\n");
}
}

// mapaccess2(hmap *map[any]any, key any) (val any, pres bool);
#pragma textflag 7
void
runtime·mapaccess2(MapType *t, Hmap *h, ...)
{
byte *ak, *av, *ap;

if(h == nil) {
ak = (byte*)(&h + 1);
av = ak + runtime·rnd(t->key->size, Structrnd);
ap = av + t->elem->size;
} else {
ak = (byte*)&h + h->ko1;
av = (byte*)&h + h->vo1;
ap = (byte*)&h + h->po1;
}

runtime·mapaccess(t, h, ak, av, ap);

if(debug) {
runtime·prints("runtime.mapaccess2: map=");
runtime·printpointer(h);
runtime·prints("; key=");
h->keyalg->print(h->keysize, ak);
runtime·prints("; val=");
h->valalg->print(h->valsize, av);
runtime·prints("; pres=");
runtime·printbool(*ap);
runtime·prints("\n");
}
}

// For reflect:
// func mapaccess(t type, h map, key iword) (val iword, pres bool)
// where an iword is the same word an interface value would use:
// the actual data if it fits, or else a pointer to the data.
void
reflect·mapaccess(MapType *t, Hmap *h, uintptr key, uintptr val, bool pres)
{
byte *ak, *av;

if(t->key->size <= sizeof(key))
ak = (byte*)&key;
else
ak = (byte*)key;
val = 0;
pres = false;
if(t->elem->size <= sizeof(val))
av = (byte*)&val;
else {
av = runtime·mal(t->elem->size);
val = (uintptr)av;
}
runtime·mapaccess(t, h, ak, av, &pres);
FLUSH(&val);
FLUSH(&pres);
}

void
runtime·mapassign(MapType *t, Hmap *h, byte *ak, byte *av)
{
byte *res;
int32 hit;

USED(t);

if(h == nil)
runtime·panicstring("assignment to entry in nil map");

if(runtime·gcwaiting)
runtime·gosched();

res = nil;
if(av == nil) {
hash_remove(h, ak, (void**)&res);
return;
}

hit = hash_insert(h, ak, (void**)&res);
if(!hit && h->indirectval)
*(void**)(res+h->datavo) = runtime·mal(h->valsize);
h->keyalg->copy(h->keysize, res, ak);
h->valalg->copy(h->valsize, hash_indirect(h, res+h->datavo), av);

if(debug) {
runtime·prints("mapassign: map=");
runtime·printpointer(h);
runtime·prints("; key=");
h->keyalg->print(h->keysize, ak);
runtime·prints("; val=");
h->valalg->print(h->valsize, av);
runtime·prints("; hit=");
runtime·printint(hit);
runtime·prints("; res=");
runtime·printpointer(res);
runtime·prints("\n");
}
}

// mapassign1(mapType *type, hmap *map[any]any, key any, val any);
#pragma textflag 7
void
runtime·mapassign1(MapType *t, Hmap *h, ...)
{
byte *ak, *av;

if(h == nil)
runtime·panicstring("assignment to entry in nil map");

ak = (byte*)&h + h->ko2;
av = (byte*)&h + h->vo2;

runtime·mapassign(t, h, ak, av);
}

// mapassign2(mapType *type, hmap *map[any]any, key any, val any, pres bool);
#pragma textflag 7
void
runtime·mapassign2(MapType *t, Hmap *h, ...)
{
byte *ak, *av, *ap;

if(h == nil)
runtime·panicstring("assignment to entry in nil map");

ak = (byte*)&h + h->ko2;
av = (byte*)&h + h->vo2;
ap = (byte*)&h + h->po2;

if(*ap == false)
av = nil; // delete

runtime·mapassign(t, h, ak, av);

if(debug) {
runtime·prints("mapassign2: map=");
runtime·printpointer(h);
runtime·prints("; key=");
h->keyalg->print(h->keysize, ak);
runtime·prints("\n");
}
}

// For reflect:
// func mapassign(t type h map, key, val iword, pres bool)
// where an iword is the same word an interface value would use:
// the actual data if it fits, or else a pointer to the data.
void
reflect·mapassign(MapType *t, Hmap *h, uintptr key, uintptr val, bool pres)
{
byte *ak, *av;

if(h == nil)
runtime·panicstring("assignment to entry in nil map");
if(h->keysize <= sizeof(key))
ak = (byte*)&key;
else
ak = (byte*)key;
if(h->valsize <= sizeof(val))
av = (byte*)&val;
else
av = (byte*)val;
if(!pres)
av = nil;
runtime·mapassign(t, h, ak, av);
}

// mapiterinit(mapType *type, hmap *map[any]any, hiter *any);
void
runtime·mapiterinit(MapType*, Hmap *h, struct hash_iter *it)
{
if(h == nil) {
it->data = nil;
return;
}
hash_iter_init(h, it);
it->data = hash_next(it);
if(debug) {
runtime·prints("runtime.mapiterinit: map=");
runtime·printpointer(h);
runtime·prints("; iter=");
runtime·printpointer(it);
runtime·prints("; data=");
runtime·printpointer(it->data);
runtime·prints("\n");
}
}

// For reflect:
// func mapiterinit(h map) (it iter)
void
reflect·mapiterinit(MapType *t, Hmap *h, struct hash_iter *it)
{
it = runtime·mal(sizeof *it);
FLUSH(&it);
runtime·mapiterinit(t, h, it);
}

// mapiternext(hiter *any);
void
runtime·mapiternext(struct hash_iter *it)
{
if(runtime·gcwaiting)
runtime·gosched();

it->data = hash_next(it);
if(debug) {
runtime·prints("runtime.mapiternext: iter=");
runtime·printpointer(it);
runtime·prints("; data=");
runtime·printpointer(it->data);
runtime·prints("\n");
}
}

// For reflect:
// func mapiternext(it iter)
void
reflect·mapiternext(struct hash_iter *it)
{
runtime·mapiternext(it);
}

// mapiter1(hiter *any) (key any);
#pragma textflag 7
void
runtime·mapiter1(struct hash_iter *it, ...)
{
Hmap *h;
byte *ak, *res;

h = it->h;
ak = (byte*)&it + h->ko0;

res = it->data;
if(res == nil)
runtime·throw("runtime.mapiter1: key:val nil pointer");

h->keyalg->copy(h->keysize, ak, res);

if(debug) {
runtime·prints("mapiter2: iter=");
runtime·printpointer(it);
runtime·prints("; map=");
runtime·printpointer(h);
runtime·prints("\n");
}
}

bool
runtime·mapiterkey(struct hash_iter *it, void *ak)
{
Hmap *h;
byte *res;

h = it->h;
res = it->data;
if(res == nil)
return false;
h->keyalg->copy(h->keysize, ak, res);
return true;
}

// For reflect:
// func mapiterkey(h map) (key iword, ok bool)
// where an iword is the same word an interface value would use:
// the actual data if it fits, or else a pointer to the data.
void
reflect·mapiterkey(struct hash_iter *it, uintptr key, bool ok)
{
Hmap *h;
byte *res;

key = 0;
ok = false;
h = it->h;
res = it->data;
if(res == nil) {
key = 0;
ok = false;
} else {
key = 0;
if(h->keysize <= sizeof(key))
h->keyalg->copy(h->keysize, (byte*)&key, res);
else
key = (uintptr)res;
ok = true;
}
FLUSH(&key);
FLUSH(&ok);
}

// For reflect:
// func maplen(h map) (len int32)
// Like len(m) in the actual language, we treat the nil map as length 0.
void
reflect·maplen(Hmap *h, int32 len)
{
if(h == nil)
len = 0;
else
len = h->count;
FLUSH(&len);
}

// mapiter2(hiter *any) (key any, val any);
#pragma textflag 7
void
runtime·mapiter2(struct hash_iter *it, ...)
{
Hmap *h;
byte *ak, *av, *res;

h = it->h;
ak = (byte*)&it + h->ko0;
av = (byte*)&it + h->vo0;

res = it->data;
if(res == nil)
runtime·throw("runtime.mapiter2: key:val nil pointer");

h->keyalg->copy(h->keysize, ak, res);
h->valalg->copy(h->valsize, av, hash_indirect(h, res+h->datavo));

if(debug) {
runtime·prints("mapiter2: iter=");
runtime·printpointer(it);
runtime·prints("; map=");
runtime·printpointer(h);
runtime·prints("\n");
}
}

Change log

aaf8ddb0c780 by Russ Cox <r...@golang.org> on Oct 1, 2011   Diff
runtime: fix map memory leak

The map implementation was using the C
idiom of using
a pointer just past the end of its table
as a limit pointer.
Unfortunately, the garbage collector sees
that pointer as
pointing at the block adjacent to the map
table, pinning
in memory a block that would otherwise be
freed.
...
Go to: 

Older revisions

13d7c38f8340 by Russ Cox <r...@golang.org> on Aug 17, 2011   Diff
gc: implement nil map support

The spec has defined nil maps this way
for months.
I'm behind.
...
c162ec4be385 by Ian Lance Taylor <i...@golang.org> on Jul 24, 2011   Diff
runtime: remove rnd calls that pass a
second argument of 1

When rnd is called with a second
argument of 1, it simply
...
47bd15b15056 by Russ Cox <r...@golang.org> on Apr 18, 2011   Diff
reflect: more efficient; cannot Set
result of NewValue anymore

 * Reduces malloc counts during gob
encoder/decoder test from 6/6 to 3/5.
...
All revisions of this file

File info

Size: 30488 bytes, 1180 lines
Powered by Google Project Hosting