forked from klando/pgfincore
-
Notifications
You must be signed in to change notification settings - Fork 0
/
pgfincore.c
1165 lines (1006 loc) · 28 KB
/
pgfincore.c
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
/*
* PgFincore
* This project let you see and mainpulate objects in the FS page cache
* Copyright (C) 2009-2011 Cédric Villemain
*/
/* { POSIX stuff */
#define _XOPEN_SOURCE 600 /* fadvise */
#include <stdlib.h> /* exit, calloc, free */
#include <sys/stat.h> /* stat, fstat */
#include <sys/types.h> /* size_t, mincore */
#include <unistd.h> /* sysconf, close */
#include <sys/mman.h> /* mmap, mincore */
#include <fcntl.h> /* fadvise */
/* } */
/* { PostgreSQL stuff */
#include "postgres.h" /* general Postgres declarations */
#include "access/heapam.h" /* relation_open */
#include "catalog/catalog.h" /* relpath */
#include "catalog/namespace.h" /* makeRangeVarFromNameList */
#include "utils/builtins.h" /* textToQualifiedNameList */
#include "utils/rel.h" /* Relation */
#include "utils/varbit.h" /* bitstring datatype */
#include "funcapi.h" /* SRF */
#include "catalog/pg_type.h" /* TEXTOID for tuple_desc */
#include "storage/fd.h"
#ifdef PG_VERSION_NUM
#define PG_MAJOR_VERSION (PG_VERSION_NUM / 100)
#else
#error "Unknown postgresql version"
#endif
#if PG_VERSION_NUM < 80300
#error "Unsupported postgresql version"
#endif
#if PG_VERSION_NUM > 90299
#include "access/htup_details.h" /* 9.3 heap_form_tuple */
#include "common/relpath.h" /* 9.3 relpathbackend */
#endif
#ifdef PG_MODULE_MAGIC
PG_MODULE_MAGIC;
#endif
/* } */
#define PGSYSCONF_COLS 3
#define PGFADVISE_COLS 4
#define PGFADVISE_LOADER_COLS 5
#define PGFINCORE_COLS 10
#define PGF_WILLNEED 10
#define PGF_DONTNEED 20
#define PGF_NORMAL 30
#define PGF_SEQUENTIAL 40
#define PGF_RANDOM 50
#define FINCORE_PRESENT 0x1
#define FINCORE_DIRTY 0x2
#ifndef HAVE_FINCORE
#define FINCORE_BITS 1
#else
#define FINCORE_BITS 2
#endif
/*
* pgfadvise_fctx structure is needed
* to keep track of relation path, segment number, ...
*/
typedef struct
{
int advice; /* the posix_fadvise advice */
TupleDesc tupd; /* the tuple descriptor */
Relation rel; /* the relation */
unsigned int segcount; /* the segment current number */
char *relationpath; /* the relation path */
} pgfadvise_fctx;
/*
* pgfadvise structure is needed
* to return values
*/
typedef struct
{
size_t pageSize; /* os page size */
size_t pagesFree; /* free page cache */
size_t filesize; /* the filesize */
} pgfadviseStruct;
/*
* pgfloader structure is needed
* to return values
*/
typedef struct
{
size_t pageSize; /* os page size */
size_t pagesFree; /* free page cache */
size_t pagesLoaded; /* pages loaded */
size_t pagesUnloaded; /* pages unloaded */
} pgfloaderStruct;
/*
* pgfincore_fctx structure is needed
* to keep track of relation path, segment number, ...
*/
typedef struct
{
bool getvector; /* output varbit data ? */
TupleDesc tupd; /* the tuple descriptor */
Relation rel; /* the relation */
unsigned int segcount; /* the segment current number */
char *relationpath; /* the relation path */
} pgfincore_fctx;
/*
* pgfadvise_loader_struct structure is needed
* to keep track of relation path, segment number, ...
*/
typedef struct
{
size_t pageSize; /* os page size */
size_t pagesFree; /* free page cache */
size_t rel_os_pages;
size_t pages_mem;
size_t group_mem;
size_t pages_dirty;
size_t group_dirty;
VarBit *databit;
} pgfincoreStruct;
Datum pgsysconf(PG_FUNCTION_ARGS);
Datum pgfadvise(PG_FUNCTION_ARGS);
static int pgfadvise_file(char *filename, int advice, pgfadviseStruct *pgfdv);
Datum pgfadvise_loader(PG_FUNCTION_ARGS);
static int pgfadvise_loader_file(char *filename,
bool willneed, bool dontneed,
VarBit *databit,
pgfloaderStruct *pgfloader);
Datum pgfincore(PG_FUNCTION_ARGS);
static int pgfincore_file(char *filename, pgfincoreStruct *pgfncr);
Datum pgfincore_drawer(PG_FUNCTION_ARGS);
/*
* We need to add some handler to keep the code clean
* and support 8.3, 8.4 and 9.0
*/
#if PG_MAJOR_VERSION == 803
#if defined(HAVE_DECL_POSIX_FADVISE)
#define USE_POSIX_FADVISE
#endif
char *text_to_cstring(const text *t);
text *cstring_to_text(const char *s);
text *cstring_to_text_with_len(const char *s, int len);
char *
text_to_cstring(const text *t)
{
/* must cast away the const, unfortunately */
text *tunpacked = pg_detoast_datum_packed((struct varlena *) t);
int len = VARSIZE_ANY_EXHDR(tunpacked);
char *result;
result = (char *) palloc(len + 1);
memcpy(result, VARDATA_ANY(tunpacked), len);
result[len] = '\0';
if (tunpacked != t)
pfree(tunpacked);
return result;
}
text *
cstring_to_text_with_len(const char *s, int len)
{
text *result = (text *) palloc(len + VARHDRSZ);
SET_VARSIZE(result, len + VARHDRSZ);
memcpy(VARDATA(result), s, len);
return result;
}
text *
cstring_to_text(const char *s)
{
return cstring_to_text_with_len(s, strlen(s));
}
#define CStringGetTextDatum(s) PointerGetDatum(cstring_to_text(s))
#define relpathpg(rel, forkName) \
relpath((rel)->rd_node)
#elif PG_MAJOR_VERSION == 804 || PG_MAJOR_VERSION == 900
#define relpathpg(rel, forkName) \
relpath((rel)->rd_node, forkname_to_number(text_to_cstring(forkName)))
#else
#define relpathpg(rel, forkName) \
relpathbackend((rel)->rd_node, (rel)->rd_backend, (forkname_to_number(text_to_cstring(forkName))))
#endif
/*
* pgsysconf
* just output the actual system value for
* _SC_PAGESIZE --> Page Size
* _SC_AVPHYS_PAGES --> Free page in memory
* _SC_PHYS_PAGES --> Total memory
*
*/
PG_FUNCTION_INFO_V1(pgsysconf);
Datum
pgsysconf(PG_FUNCTION_ARGS)
{
HeapTuple tuple;
TupleDesc tupdesc;
Datum values[PGSYSCONF_COLS];
bool nulls[PGSYSCONF_COLS];
/* initialize nulls array to build the tuple */
memset(nulls, 0, sizeof(nulls));
/* Build a tuple descriptor for our result type */
if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
elog(ERROR, "pgsysconf: return type must be a row type");
/* Page size */
values[0] = Int64GetDatum(sysconf(_SC_PAGESIZE));
/* free page in memory */
values[1] = Int64GetDatum(sysconf(_SC_AVPHYS_PAGES));
/* total memory */
values[2] = Int64GetDatum(sysconf(_SC_PHYS_PAGES));
/* Build and return the result tuple. */
tuple = heap_form_tuple(tupdesc, values, nulls);
PG_RETURN_DATUM( HeapTupleGetDatum(tuple) );
}
#if defined(USE_POSIX_FADVISE)
/*
* pgfadvise_file
*/
static int
pgfadvise_file(char *filename, int advice, pgfadviseStruct *pgfdv)
{
/*
* We use the AllocateFile(2) provided by PostgreSQL. We're going to
* close it ourselves even if PostgreSQL close it anyway at transaction
* end.
*/
FILE *fp;
int fd;
struct stat st;
int adviceFlag;
/*
* OS Page size and Free pages
*/
pgfdv->pageSize = sysconf(_SC_PAGESIZE);
/*
* Fopen and fstat file
* fd will be provided to posix_fadvise
* if there is no file, just return 1, it is expected to leave the SRF
*/
fp = AllocateFile(filename, "rb");
if (fp == NULL)
return 1;
fd = fileno(fp);
if (fstat(fd, &st) == -1)
{
FreeFile(fp);
elog(ERROR, "pgfadvise: Can not stat object file : %s", filename);
return 2;
}
/*
* the file size is used in the SRF to output the number of pages used by
* the segment
*/
pgfdv->filesize = st.st_size;
elog(DEBUG1, "pgfadvise: working on %s of %lld bytes",
filename, (long long int) pgfdv->filesize);
/* FADVISE_WILLNEED */
if (advice == PGF_WILLNEED)
{
adviceFlag = POSIX_FADV_WILLNEED;
elog(DEBUG1, "pgfadvise: setting advice POSIX_FADV_WILLNEED");
}
/* FADVISE_DONTNEED */
else if (advice == PGF_DONTNEED)
{
adviceFlag = POSIX_FADV_DONTNEED;
elog(DEBUG1, "pgfadvise: setting advice POSIX_FADV_DONTNEED");
}
/* POSIX_FADV_NORMAL */
else if (advice == PGF_NORMAL)
{
adviceFlag = POSIX_FADV_NORMAL;
elog(DEBUG1, "pgfadvise: setting advice POSIX_FADV_NORMAL");
}
/* POSIX_FADV_SEQUENTIAL */
else if (advice == PGF_SEQUENTIAL)
{
adviceFlag = POSIX_FADV_SEQUENTIAL;
elog(DEBUG1, "pgfadvise: setting advice POSIX_FADV_SEQUENTIAL");
}
/* POSIX_FADV_RANDOM */
else if (advice == PGF_RANDOM)
{
adviceFlag = POSIX_FADV_RANDOM;
elog(DEBUG1, "pgfadvise: setting advice POSIX_FADV_RANDOM");
}
else
{
elog(ERROR, "pgfadvise: invalid advice: %d", advice);
return 2;
}
/*
* Call posix_fadvise with the relevant advice on the file descriptor
*/
posix_fadvise(fd, 0, 0, adviceFlag);
/* close the file */
FreeFile(fp);
/*
* OS things : Pages free
*/
pgfdv->pagesFree = sysconf(_SC_AVPHYS_PAGES);
return 0;
}
#else
static int
pgfadvise_file(char *filename, int advice, pgfadviseStruct *pgfdv)
{
elog(ERROR, "POSIX_FADVISE UNSUPPORTED on your platform");
return 9;
}
#endif
/*
* pgfadvise is a function that handle the process to have a sharelock
* on the relation and to walk the segments.
* for each segment it call the posix_fadvise with the required flag
* parameter
*/
PG_FUNCTION_INFO_V1(pgfadvise);
Datum
pgfadvise(PG_FUNCTION_ARGS)
{
/* SRF Stuff */
FuncCallContext *funcctx;
pgfadvise_fctx *fctx;
/* our structure use to return values */
pgfadviseStruct *pgfdv;
/* our return value, 0 for success */
int result;
/* The file we are working on */
char filename[MAXPGPATH];
/* stuff done only on the first call of the function */
if (SRF_IS_FIRSTCALL())
{
MemoryContext oldcontext;
Oid relOid = PG_GETARG_OID(0);
text *forkName = PG_GETARG_TEXT_P(1);
int advice = PG_GETARG_INT32(2);
/*
* Postgresql stuff to return a tuple
*/
TupleDesc tupdesc;
/* create a function context for cross-call persistence */
funcctx = SRF_FIRSTCALL_INIT();
/*
* switch to memory context appropriate for multiple function calls
*/
oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
/* allocate memory for user context */
fctx = (pgfadvise_fctx *) palloc(sizeof(pgfadvise_fctx));
/* Build a tuple descriptor for our result type */
if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
elog(ERROR, "pgfadvise: return type must be a row type");
/* provide the tuple descriptor to the fonction structure */
fctx->tupd = tupdesc;
/* open the current relation, accessShareLock */
// TODO use try_relation_open instead ?
fctx->rel = relation_open(relOid, AccessShareLock);
/* we get the common part of the filename of each segment of a relation */
fctx->relationpath = relpathpg(fctx->rel, forkName);
/* Here we keep track of current action in all calls */
fctx->advice = advice;
/* segcount is used to get the next segment of the current relation */
fctx->segcount = 0;
/* And finally we keep track of our initialization */
elog(DEBUG1, "pgfadvise: init done for %s, in fork %s",
fctx->relationpath, text_to_cstring(forkName));
funcctx->user_fctx = fctx;
MemoryContextSwitchTo(oldcontext);
}
/* After the first call, we recover our context */
funcctx = SRF_PERCALL_SETUP();
fctx = funcctx->user_fctx;
/*
* If we are still looking the first segment
* relationpath should not be suffixed
*/
if (fctx->segcount == 0)
snprintf(filename,
MAXPGPATH,
"%s",
fctx->relationpath);
else
snprintf(filename,
MAXPGPATH,
"%s.%u",
fctx->relationpath,
fctx->segcount);
elog(DEBUG1, "pgfadvise: about to work with %s, current advice : %d",
filename, fctx->advice);
/*
* Call posix_fadvise with the advice, returning the structure
*/
pgfdv = (pgfadviseStruct *) palloc(sizeof(pgfadviseStruct));
result = pgfadvise_file(filename, fctx->advice, pgfdv);
/*
* When we have work with all segments of the current relation
* We exit from the SRF
* Else we build and return the tuple for this segment
*/
if (result)
{
elog(DEBUG1, "pgfadvise: closing %s", fctx->relationpath);
relation_close(fctx->rel, AccessShareLock);
pfree(fctx);
SRF_RETURN_DONE(funcctx);
}
else {
/*
* Postgresql stuff to return a tuple
*/
HeapTuple tuple;
Datum values[PGFADVISE_COLS];
bool nulls[PGFADVISE_COLS];
/* initialize nulls array to build the tuple */
memset(nulls, 0, sizeof(nulls));
/* prepare the number of the next segment */
fctx->segcount++;
/* Filename */
values[0] = CStringGetTextDatum( filename );
/* os page size */
values[1] = Int64GetDatum( (int64) pgfdv->pageSize );
/* number of pages used by segment */
values[2] = Int64GetDatum( (int64) ((pgfdv->filesize+pgfdv->pageSize-1)/pgfdv->pageSize) );
/* free page cache */
values[3] = Int64GetDatum( (int64) pgfdv->pagesFree );
/* Build the result tuple. */
tuple = heap_form_tuple(fctx->tupd, values, nulls);
/* Ok, return results, and go for next call */
SRF_RETURN_NEXT(funcctx, HeapTupleGetDatum(tuple));
}
}
#if defined(USE_POSIX_FADVISE)
/*
* pgfadvise_file
*/
static int
pgfadvise_loader_file(char *filename,
bool willneed, bool dontneed, VarBit *databit,
pgfloaderStruct *pgfloader)
{
bits8 *sp;
int bitlen;
bits8 x;
int i, k;
/*
* We use the AllocateFile(2) provided by PostgreSQL. We're going to
* close it ourselves even if PostgreSQL close it anyway at transaction
* end.
*/
FILE *fp;
int fd;
struct stat st;
/*
* OS things : Page size
*/
pgfloader->pageSize = sysconf(_SC_PAGESIZE);
/*
* we count the action we perform
* both are theorical : we don't know if the page was or not in memory
* when we call posix_fadvise
*/
pgfloader->pagesLoaded = 0;
pgfloader->pagesUnloaded = 0;
/*
* Fopen and fstat file
* fd will be provided to posix_fadvise
* if there is no file, just return 1, it is expected to leave the SRF
*/
fp = AllocateFile(filename, "rb");
if (fp == NULL)
return 1;
fd = fileno(fp);
if (fstat(fd, &st) == -1)
{
FreeFile(fp);
elog(ERROR, "pgfadvise_loader: Can not stat object file: %s", filename);
return 2;
}
elog(DEBUG1, "pgfadvise_loader: working on %s", filename);
bitlen = VARBITLEN(databit);
sp = VARBITS(databit);
for (i = 0; i < bitlen - BITS_PER_BYTE; i += BITS_PER_BYTE, sp++)
{
x = *sp;
/* Is this bit set ? */
for (k = 0; k < BITS_PER_BYTE; k++)
{
if (IS_HIGHBIT_SET(x))
{
if (willneed)
{
(void) posix_fadvise(fd,
((i+k) * pgfloader->pageSize),
pgfloader->pageSize,
POSIX_FADV_WILLNEED);
pgfloader->pagesLoaded++;
}
}
else if (dontneed)
{
(void) posix_fadvise(fd,
((i+k) * pgfloader->pageSize),
pgfloader->pageSize,
POSIX_FADV_DONTNEED);
pgfloader->pagesUnloaded++;
}
x <<= 1;
}
}
/*
* XXX this copy/paste of code to finnish to walk the bits is not pretty
*/
if (i < bitlen)
{
/* print the last partial byte */
x = *sp;
for (k = i; k < bitlen; k++)
{
if (IS_HIGHBIT_SET(x))
{
if (willneed)
{
(void) posix_fadvise(fd,
(k * pgfloader->pageSize),
pgfloader->pageSize,
POSIX_FADV_WILLNEED);
pgfloader->pagesLoaded++;
}
}
else if (dontneed)
{
(void) posix_fadvise(fd,
(k * pgfloader->pageSize),
pgfloader->pageSize,
POSIX_FADV_DONTNEED);
pgfloader->pagesUnloaded++;
}
x <<= 1;
}
}
FreeFile(fp);
/*
* OS things : Pages free
*/
pgfloader->pagesFree = sysconf(_SC_AVPHYS_PAGES);
return 0;
}
#else
static int
pgfadvise_loader_file(char *filename,
bool willneed, bool dontneed, VarBit *databit,
pgfloaderStruct *pgfloader)
{
elog(ERROR, "POSIX_FADVISE UNSUPPORTED on your platform");
return 9;
}
#endif
/*
*
* pgfadv_loader to handle work with varbit map of buffer cache.
* it is actually used for loading/unloading block to/from buffer cache
*
*/
PG_FUNCTION_INFO_V1(pgfadvise_loader);
Datum
pgfadvise_loader(PG_FUNCTION_ARGS)
{
Oid relOid = PG_GETARG_OID(0);
text *forkName = PG_GETARG_TEXT_P(1);
int segmentNumber = PG_GETARG_INT32(2);
bool willneed = PG_GETARG_BOOL(3);
bool dontneed = PG_GETARG_BOOL(4);
VarBit *databit;
/* our structure use to return values */
pgfloaderStruct *pgfloader;
Relation rel;
char *relationpath;
char filename[MAXPGPATH];
/* our return value, 0 for success */
int result;
/*
* Postgresql stuff to return a tuple
*/
HeapTuple tuple;
TupleDesc tupdesc;
Datum values[PGFADVISE_LOADER_COLS];
bool nulls[PGFADVISE_LOADER_COLS];
if (PG_ARGISNULL(5))
elog(ERROR, "pgfadvise_loader: databit argument shouldn't be NULL");
databit = PG_GETARG_VARBIT_P(5);
/* initialize nulls array to build the tuple */
memset(nulls, 0, sizeof(nulls));
/* Build a tuple descriptor for our result type */
if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
elog(ERROR, "return type must be a row type");
/* open the current relation in accessShareLock */
rel = relation_open(relOid, AccessShareLock);
/* we get the common part of the filename of each segment of a relation */
relationpath = relpathpg(rel, forkName);
/*
* If we are looking the first segment,
* relationpath should not be suffixed
*/
if (segmentNumber == 0)
snprintf(filename,
MAXPGPATH,
"%s",
relationpath);
else
snprintf(filename,
MAXPGPATH,
"%s.%u",
relationpath,
(int) segmentNumber);
/*
* We don't need the relation anymore
* the only purpose was to get a consistent filename
* (if file disappear, an error is logged)
*/
relation_close(rel, AccessShareLock);
/*
* Call pgfadvise_loader with the varbit
*/
pgfloader = (pgfloaderStruct *) palloc(sizeof(pgfloaderStruct));
result = pgfadvise_loader_file(filename,
willneed, dontneed, databit,
pgfloader);
if (result != 0)
elog(ERROR, "Can't read file %s, fork(%s)",
filename, text_to_cstring(forkName));
/* Filename */
values[0] = CStringGetTextDatum( filename );
/* os page size */
values[1] = Int64GetDatum( pgfloader->pageSize );
/* free page cache */
values[2] = Int64GetDatum( pgfloader->pagesFree );
/* pages loaded */
values[3] = Int64GetDatum( pgfloader->pagesLoaded );
/* pages unloaded */
values[4] = Int64GetDatum( pgfloader->pagesUnloaded );
/* Build and return the result tuple. */
tuple = heap_form_tuple(tupdesc, values, nulls);
PG_RETURN_DATUM( HeapTupleGetDatum(tuple) );
}
/*
* pgfincore_file handle the mmaping, mincore process (and access file, etc.)
*/
static int
pgfincore_file(char *filename, pgfincoreStruct *pgfncr)
{
int flag=1;
int flag_dirty=1;
int len, bitlen;
bits8 *r;
bits8 x = 0;
register int64 pageIndex;
/*
* We use the AllocateFile(2) provided by PostgreSQL. We're going to
* close it ourselves even if PostgreSQL close it anyway at transaction
* end.
*/
FILE *fp;
int fd;
struct stat st;
#ifndef HAVE_FINCORE
void *pa = (char *) 0;
#endif
unsigned char *vec = (unsigned char *) 0;
/*
* OS Page size
*/
pgfncr->pageSize = sysconf(_SC_PAGESIZE);
/*
* Initialize counters
*/
pgfncr->pages_mem = 0;
pgfncr->group_mem = 0;
pgfncr->pages_dirty = 0;
pgfncr->group_dirty = 0;
pgfncr->rel_os_pages = 0;
/*
* Fopen and fstat file
* fd will be provided to posix_fadvise
* if there is no file, just return 1, it is expected to leave the SRF
*/
fp = AllocateFile(filename, "rb");
if (fp == NULL)
return 1;
fd = fileno(fp);
if (fstat(fd, &st) == -1)
{
FreeFile(fp);
elog(ERROR, "Can not stat object file : %s",
filename);
return 2;
}
/*
* if file ok
* then process
*/
if (st.st_size != 0)
{
/* number of pages in the current file */
pgfncr->rel_os_pages = (st.st_size+pgfncr->pageSize-1)/pgfncr->pageSize;
#ifndef HAVE_FINCORE
pa = mmap(NULL, st.st_size, PROT_NONE, MAP_SHARED, fd, 0);
if (pa == MAP_FAILED)
{
FreeFile(fp);
elog(ERROR, "Can not mmap object file : %s, errno = %i,%s\nThis error can happen if there is not enought space in memory to do the projection. Please mail [email protected] with '[pgfincore] ENOMEM' as subject.",
filename, errno, strerror(errno));
return 3;
}
#endif
/* Prepare our vector containing all blocks information */
vec = calloc(1, (st.st_size+pgfncr->pageSize-1)/pgfncr->pageSize);
if ((void *)0 == vec)
{
#ifndef HAVE_FINCORE
munmap(pa, st.st_size);
#endif
FreeFile(fp);
elog(ERROR, "Can not calloc object file : %s",
filename);
return 4;
}
#ifndef HAVE_FINCORE
/* Affect vec with mincore */
if (mincore(pa, st.st_size, vec) != 0)
{
munmap(pa, st.st_size);
elog(ERROR, "mincore(%p, %lld, %p): %s\n",
pa, (long long int)st.st_size, vec, strerror(errno));
#else
/* Affect vec with fincore */
if (fincore(fd, 0, st.st_size, vec) != 0)
{
elog(ERROR, "fincore(%u, 0, %lld, %p): %s\n",
fd, (long long int)st.st_size, vec, strerror(errno));
#endif
free(vec);
FreeFile(fp);
return 5;
}
/*
* prepare the bit string
*/
bitlen = FINCORE_BITS * ((st.st_size+pgfncr->pageSize-1)/pgfncr->pageSize);
len = VARBITTOTALLEN(bitlen);
/*
* set to 0 so that *r is always initialised and string is zero-padded
* XXX: do we need to free that ?
*/
pgfncr->databit = (VarBit *) palloc0(len);
SET_VARSIZE(pgfncr->databit, len);
VARBITLEN(pgfncr->databit) = bitlen;
r = VARBITS(pgfncr->databit);
x = HIGHBIT;
/* handle the results */
for (pageIndex = 0; pageIndex <= pgfncr->rel_os_pages; pageIndex++)
{
// block in memory
if (vec[pageIndex] & FINCORE_PRESENT)
{
pgfncr->pages_mem++;
*r |= x;
if (FINCORE_BITS > 1)
{
if (vec[pageIndex] & FINCORE_DIRTY)
{
pgfncr->pages_dirty++;
*r |= (x >> 1);
/* we flag to detect contigous blocks in the same state */
if (flag_dirty)
pgfncr->group_dirty++;
flag_dirty = 0;
}
else
flag_dirty = 1;
}
elog (DEBUG5, "in memory blocks : %lld / %lld",
(long long int) pageIndex, (long long int) pgfncr->rel_os_pages);
/* we flag to detect contigous blocks in the same state */
if (flag)
pgfncr->group_mem++;
flag = 0;
}
else
flag=1;
x >>= FINCORE_BITS;
if (x == 0)
{
x = HIGHBIT;
r++;
}
}
}
elog(DEBUG1, "pgfincore %s: %lld of %lld block in linux cache, %lld groups",
filename, (long long int) pgfncr->pages_mem, (long long int) pgfncr->rel_os_pages, (long long int) pgfncr->group_mem);
/*
* free and close
*/
free(vec);
#ifndef HAVE_FINCORE
munmap(pa, st.st_size);
#endif
FreeFile(fp);
/*
* OS things : Pages free
*/
pgfncr->pagesFree = sysconf(_SC_AVPHYS_PAGES);
return 0;
}
/*
* pgfincore is a function that handle the process to have a sharelock
* on the relation and to walk the segments.
* for each segment it call the appropriate function depending on 'action'
* parameter
*/
PG_FUNCTION_INFO_V1(pgfincore);
Datum
pgfincore(PG_FUNCTION_ARGS)
{
/* SRF Stuff */
FuncCallContext *funcctx;
pgfincore_fctx *fctx;
/* our structure use to return values */
pgfincoreStruct *pgfncr;
/* our return value, 0 for success */
int result;
/* The file we are working on */
char filename[MAXPGPATH];
/* stuff done only on the first call of the function */
if (SRF_IS_FIRSTCALL())
{
MemoryContext oldcontext;
Oid relOid = PG_GETARG_OID(0);
text *forkName = PG_GETARG_TEXT_P(1);
bool getvector = PG_GETARG_BOOL(2);
/*
* Postgresql stuff to return a tuple
*/
TupleDesc tupdesc;
/* create a function context for cross-call persistence */
funcctx = SRF_FIRSTCALL_INIT();
/*
* switch to memory context appropriate for multiple function calls
*/
oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
/* allocate memory for user context */
fctx = (pgfincore_fctx *) palloc(sizeof(pgfincore_fctx));
/* Build a tuple descriptor for our result type */
if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
elog(ERROR, "pgfadvise: return type must be a row type");
/* provide the tuple descriptor to the fonction structure */
fctx->tupd = tupdesc;
/* are we going to grab and output the varbit data (can be large) */
fctx->getvector = getvector;
/* open the current relation, accessShareLock */
// TODO use try_relation_open instead ?
fctx->rel = relation_open(relOid, AccessShareLock);
/* we get the common part of the filename of each segment of a relation */
fctx->relationpath = relpathpg(fctx->rel, forkName);
/* segcount is used to get the next segment of the current relation */