1 /*
2 * dbsize.c
3 * Database object size functions, and related inquiries
4 *
5 * Copyright (c) 2002-2021, PostgreSQL Global Development Group
6 *
7 * IDENTIFICATION
8 * src/backend/utils/adt/dbsize.c
9 *
10 */
11
12 #include "postgres.h"
13
14 #include <sys/stat.h>
15
16 #include "access/htup_details.h"
17 #include "access/relation.h"
18 #include "catalog/catalog.h"
19 #include "catalog/namespace.h"
20 #include "catalog/pg_authid.h"
21 #include "catalog/pg_tablespace.h"
22 #include "commands/dbcommands.h"
23 #include "commands/tablespace.h"
24 #include "miscadmin.h"
25 #include "storage/fd.h"
26 #include "utils/acl.h"
27 #include "utils/builtins.h"
28 #include "utils/numeric.h"
29 #include "utils/rel.h"
30 #include "utils/relfilenodemap.h"
31 #include "utils/relmapper.h"
32 #include "utils/syscache.h"
33
34 /* Divide by two and round away from zero */
35 #define half_rounded(x) (((x) + ((x) < 0 ? -1 : 1)) / 2)
36
37 /* Return physical size of directory contents, or 0 if dir doesn't exist */
38 static int64
db_dir_size(const char * path)39 db_dir_size(const char *path)
40 {
41 int64 dirsize = 0;
42 struct dirent *direntry;
43 DIR *dirdesc;
44 char filename[MAXPGPATH * 2];
45
46 dirdesc = AllocateDir(path);
47
48 if (!dirdesc)
49 return 0;
50
51 while ((direntry = ReadDir(dirdesc, path)) != NULL)
52 {
53 struct stat fst;
54
55 CHECK_FOR_INTERRUPTS();
56
57 if (strcmp(direntry->d_name, ".") == 0 ||
58 strcmp(direntry->d_name, "..") == 0)
59 continue;
60
61 snprintf(filename, sizeof(filename), "%s/%s", path, direntry->d_name);
62
63 if (stat(filename, &fst) < 0)
64 {
65 if (errno == ENOENT)
66 continue;
67 else
68 ereport(ERROR,
69 (errcode_for_file_access(),
70 errmsg("could not stat file \"%s\": %m", filename)));
71 }
72 dirsize += fst.st_size;
73 }
74
75 FreeDir(dirdesc);
76 return dirsize;
77 }
78
79 /*
80 * calculate size of database in all tablespaces
81 */
82 static int64
calculate_database_size(Oid dbOid)83 calculate_database_size(Oid dbOid)
84 {
85 int64 totalsize;
86 DIR *dirdesc;
87 struct dirent *direntry;
88 char dirpath[MAXPGPATH];
89 char pathname[MAXPGPATH + 21 + sizeof(TABLESPACE_VERSION_DIRECTORY)];
90 AclResult aclresult;
91
92 /*
93 * User must have connect privilege for target database or be a member of
94 * pg_read_all_stats
95 */
96 aclresult = pg_database_aclcheck(dbOid, GetUserId(), ACL_CONNECT);
97 if (aclresult != ACLCHECK_OK &&
98 !is_member_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
99 {
100 aclcheck_error(aclresult, OBJECT_DATABASE,
101 get_database_name(dbOid));
102 }
103
104 /* Shared storage in pg_global is not counted */
105
106 /* Include pg_default storage */
107 snprintf(pathname, sizeof(pathname), "base/%u", dbOid);
108 totalsize = db_dir_size(pathname);
109
110 /* Scan the non-default tablespaces */
111 snprintf(dirpath, MAXPGPATH, "pg_tblspc");
112 dirdesc = AllocateDir(dirpath);
113
114 while ((direntry = ReadDir(dirdesc, dirpath)) != NULL)
115 {
116 CHECK_FOR_INTERRUPTS();
117
118 if (strcmp(direntry->d_name, ".") == 0 ||
119 strcmp(direntry->d_name, "..") == 0)
120 continue;
121
122 snprintf(pathname, sizeof(pathname), "pg_tblspc/%s/%s/%u",
123 direntry->d_name, TABLESPACE_VERSION_DIRECTORY, dbOid);
124 totalsize += db_dir_size(pathname);
125 }
126
127 FreeDir(dirdesc);
128
129 return totalsize;
130 }
131
132 Datum
pg_database_size_oid(PG_FUNCTION_ARGS)133 pg_database_size_oid(PG_FUNCTION_ARGS)
134 {
135 Oid dbOid = PG_GETARG_OID(0);
136 int64 size;
137
138 size = calculate_database_size(dbOid);
139
140 if (size == 0)
141 PG_RETURN_NULL();
142
143 PG_RETURN_INT64(size);
144 }
145
146 Datum
pg_database_size_name(PG_FUNCTION_ARGS)147 pg_database_size_name(PG_FUNCTION_ARGS)
148 {
149 Name dbName = PG_GETARG_NAME(0);
150 Oid dbOid = get_database_oid(NameStr(*dbName), false);
151 int64 size;
152
153 size = calculate_database_size(dbOid);
154
155 if (size == 0)
156 PG_RETURN_NULL();
157
158 PG_RETURN_INT64(size);
159 }
160
161
162 /*
163 * Calculate total size of tablespace. Returns -1 if the tablespace directory
164 * cannot be found.
165 */
166 static int64
calculate_tablespace_size(Oid tblspcOid)167 calculate_tablespace_size(Oid tblspcOid)
168 {
169 char tblspcPath[MAXPGPATH];
170 char pathname[MAXPGPATH * 2];
171 int64 totalsize = 0;
172 DIR *dirdesc;
173 struct dirent *direntry;
174 AclResult aclresult;
175
176 /*
177 * User must be a member of pg_read_all_stats or have CREATE privilege for
178 * target tablespace, either explicitly granted or implicitly because it
179 * is default for current database.
180 */
181 if (tblspcOid != MyDatabaseTableSpace &&
182 !is_member_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
183 {
184 aclresult = pg_tablespace_aclcheck(tblspcOid, GetUserId(), ACL_CREATE);
185 if (aclresult != ACLCHECK_OK)
186 aclcheck_error(aclresult, OBJECT_TABLESPACE,
187 get_tablespace_name(tblspcOid));
188 }
189
190 if (tblspcOid == DEFAULTTABLESPACE_OID)
191 snprintf(tblspcPath, MAXPGPATH, "base");
192 else if (tblspcOid == GLOBALTABLESPACE_OID)
193 snprintf(tblspcPath, MAXPGPATH, "global");
194 else
195 snprintf(tblspcPath, MAXPGPATH, "pg_tblspc/%u/%s", tblspcOid,
196 TABLESPACE_VERSION_DIRECTORY);
197
198 dirdesc = AllocateDir(tblspcPath);
199
200 if (!dirdesc)
201 return -1;
202
203 while ((direntry = ReadDir(dirdesc, tblspcPath)) != NULL)
204 {
205 struct stat fst;
206
207 CHECK_FOR_INTERRUPTS();
208
209 if (strcmp(direntry->d_name, ".") == 0 ||
210 strcmp(direntry->d_name, "..") == 0)
211 continue;
212
213 snprintf(pathname, sizeof(pathname), "%s/%s", tblspcPath, direntry->d_name);
214
215 if (stat(pathname, &fst) < 0)
216 {
217 if (errno == ENOENT)
218 continue;
219 else
220 ereport(ERROR,
221 (errcode_for_file_access(),
222 errmsg("could not stat file \"%s\": %m", pathname)));
223 }
224
225 if (S_ISDIR(fst.st_mode))
226 totalsize += db_dir_size(pathname);
227
228 totalsize += fst.st_size;
229 }
230
231 FreeDir(dirdesc);
232
233 return totalsize;
234 }
235
236 Datum
pg_tablespace_size_oid(PG_FUNCTION_ARGS)237 pg_tablespace_size_oid(PG_FUNCTION_ARGS)
238 {
239 Oid tblspcOid = PG_GETARG_OID(0);
240 int64 size;
241
242 size = calculate_tablespace_size(tblspcOid);
243
244 if (size < 0)
245 PG_RETURN_NULL();
246
247 PG_RETURN_INT64(size);
248 }
249
250 Datum
pg_tablespace_size_name(PG_FUNCTION_ARGS)251 pg_tablespace_size_name(PG_FUNCTION_ARGS)
252 {
253 Name tblspcName = PG_GETARG_NAME(0);
254 Oid tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
255 int64 size;
256
257 size = calculate_tablespace_size(tblspcOid);
258
259 if (size < 0)
260 PG_RETURN_NULL();
261
262 PG_RETURN_INT64(size);
263 }
264
265
266 /*
267 * calculate size of (one fork of) a relation
268 *
269 * Note: we can safely apply this to temp tables of other sessions, so there
270 * is no check here or at the call sites for that.
271 */
272 static int64
calculate_relation_size(RelFileNode * rfn,BackendId backend,ForkNumber forknum)273 calculate_relation_size(RelFileNode *rfn, BackendId backend, ForkNumber forknum)
274 {
275 int64 totalsize = 0;
276 char *relationpath;
277 char pathname[MAXPGPATH];
278 unsigned int segcount = 0;
279
280 relationpath = relpathbackend(*rfn, backend, forknum);
281
282 for (segcount = 0;; segcount++)
283 {
284 struct stat fst;
285
286 CHECK_FOR_INTERRUPTS();
287
288 if (segcount == 0)
289 snprintf(pathname, MAXPGPATH, "%s",
290 relationpath);
291 else
292 snprintf(pathname, MAXPGPATH, "%s.%u",
293 relationpath, segcount);
294
295 if (stat(pathname, &fst) < 0)
296 {
297 if (errno == ENOENT)
298 break;
299 else
300 ereport(ERROR,
301 (errcode_for_file_access(),
302 errmsg("could not stat file \"%s\": %m", pathname)));
303 }
304 totalsize += fst.st_size;
305 }
306
307 return totalsize;
308 }
309
310 Datum
pg_relation_size(PG_FUNCTION_ARGS)311 pg_relation_size(PG_FUNCTION_ARGS)
312 {
313 Oid relOid = PG_GETARG_OID(0);
314 text *forkName = PG_GETARG_TEXT_PP(1);
315 Relation rel;
316 int64 size;
317
318 rel = try_relation_open(relOid, AccessShareLock);
319
320 /*
321 * Before 9.2, we used to throw an error if the relation didn't exist, but
322 * that makes queries like "SELECT pg_relation_size(oid) FROM pg_class"
323 * less robust, because while we scan pg_class with an MVCC snapshot,
324 * someone else might drop the table. It's better to return NULL for
325 * already-dropped tables than throw an error and abort the whole query.
326 */
327 if (rel == NULL)
328 PG_RETURN_NULL();
329
330 size = calculate_relation_size(&(rel->rd_node), rel->rd_backend,
331 forkname_to_number(text_to_cstring(forkName)));
332
333 relation_close(rel, AccessShareLock);
334
335 PG_RETURN_INT64(size);
336 }
337
338 /*
339 * Calculate total on-disk size of a TOAST relation, including its indexes.
340 * Must not be applied to non-TOAST relations.
341 */
342 static int64
calculate_toast_table_size(Oid toastrelid)343 calculate_toast_table_size(Oid toastrelid)
344 {
345 int64 size = 0;
346 Relation toastRel;
347 ForkNumber forkNum;
348 ListCell *lc;
349 List *indexlist;
350
351 toastRel = relation_open(toastrelid, AccessShareLock);
352
353 /* toast heap size, including FSM and VM size */
354 for (forkNum = 0; forkNum <= MAX_FORKNUM; forkNum++)
355 size += calculate_relation_size(&(toastRel->rd_node),
356 toastRel->rd_backend, forkNum);
357
358 /* toast index size, including FSM and VM size */
359 indexlist = RelationGetIndexList(toastRel);
360
361 /* Size is calculated using all the indexes available */
362 foreach(lc, indexlist)
363 {
364 Relation toastIdxRel;
365
366 toastIdxRel = relation_open(lfirst_oid(lc),
367 AccessShareLock);
368 for (forkNum = 0; forkNum <= MAX_FORKNUM; forkNum++)
369 size += calculate_relation_size(&(toastIdxRel->rd_node),
370 toastIdxRel->rd_backend, forkNum);
371
372 relation_close(toastIdxRel, AccessShareLock);
373 }
374 list_free(indexlist);
375 relation_close(toastRel, AccessShareLock);
376
377 return size;
378 }
379
380 /*
381 * Calculate total on-disk size of a given table,
382 * including FSM and VM, plus TOAST table if any.
383 * Indexes other than the TOAST table's index are not included.
384 *
385 * Note that this also behaves sanely if applied to an index or toast table;
386 * those won't have attached toast tables, but they can have multiple forks.
387 */
388 static int64
calculate_table_size(Relation rel)389 calculate_table_size(Relation rel)
390 {
391 int64 size = 0;
392 ForkNumber forkNum;
393
394 /*
395 * heap size, including FSM and VM
396 */
397 for (forkNum = 0; forkNum <= MAX_FORKNUM; forkNum++)
398 size += calculate_relation_size(&(rel->rd_node), rel->rd_backend,
399 forkNum);
400
401 /*
402 * Size of toast relation
403 */
404 if (OidIsValid(rel->rd_rel->reltoastrelid))
405 size += calculate_toast_table_size(rel->rd_rel->reltoastrelid);
406
407 return size;
408 }
409
410 /*
411 * Calculate total on-disk size of all indexes attached to the given table.
412 *
413 * Can be applied safely to an index, but you'll just get zero.
414 */
415 static int64
calculate_indexes_size(Relation rel)416 calculate_indexes_size(Relation rel)
417 {
418 int64 size = 0;
419
420 /*
421 * Aggregate all indexes on the given relation
422 */
423 if (rel->rd_rel->relhasindex)
424 {
425 List *index_oids = RelationGetIndexList(rel);
426 ListCell *cell;
427
428 foreach(cell, index_oids)
429 {
430 Oid idxOid = lfirst_oid(cell);
431 Relation idxRel;
432 ForkNumber forkNum;
433
434 idxRel = relation_open(idxOid, AccessShareLock);
435
436 for (forkNum = 0; forkNum <= MAX_FORKNUM; forkNum++)
437 size += calculate_relation_size(&(idxRel->rd_node),
438 idxRel->rd_backend,
439 forkNum);
440
441 relation_close(idxRel, AccessShareLock);
442 }
443
444 list_free(index_oids);
445 }
446
447 return size;
448 }
449
450 Datum
pg_table_size(PG_FUNCTION_ARGS)451 pg_table_size(PG_FUNCTION_ARGS)
452 {
453 Oid relOid = PG_GETARG_OID(0);
454 Relation rel;
455 int64 size;
456
457 rel = try_relation_open(relOid, AccessShareLock);
458
459 if (rel == NULL)
460 PG_RETURN_NULL();
461
462 size = calculate_table_size(rel);
463
464 relation_close(rel, AccessShareLock);
465
466 PG_RETURN_INT64(size);
467 }
468
469 Datum
pg_indexes_size(PG_FUNCTION_ARGS)470 pg_indexes_size(PG_FUNCTION_ARGS)
471 {
472 Oid relOid = PG_GETARG_OID(0);
473 Relation rel;
474 int64 size;
475
476 rel = try_relation_open(relOid, AccessShareLock);
477
478 if (rel == NULL)
479 PG_RETURN_NULL();
480
481 size = calculate_indexes_size(rel);
482
483 relation_close(rel, AccessShareLock);
484
485 PG_RETURN_INT64(size);
486 }
487
488 /*
489 * Compute the on-disk size of all files for the relation,
490 * including heap data, index data, toast data, FSM, VM.
491 */
492 static int64
calculate_total_relation_size(Relation rel)493 calculate_total_relation_size(Relation rel)
494 {
495 int64 size;
496
497 /*
498 * Aggregate the table size, this includes size of the heap, toast and
499 * toast index with free space and visibility map
500 */
501 size = calculate_table_size(rel);
502
503 /*
504 * Add size of all attached indexes as well
505 */
506 size += calculate_indexes_size(rel);
507
508 return size;
509 }
510
511 Datum
pg_total_relation_size(PG_FUNCTION_ARGS)512 pg_total_relation_size(PG_FUNCTION_ARGS)
513 {
514 Oid relOid = PG_GETARG_OID(0);
515 Relation rel;
516 int64 size;
517
518 rel = try_relation_open(relOid, AccessShareLock);
519
520 if (rel == NULL)
521 PG_RETURN_NULL();
522
523 size = calculate_total_relation_size(rel);
524
525 relation_close(rel, AccessShareLock);
526
527 PG_RETURN_INT64(size);
528 }
529
530 /*
531 * formatting with size units
532 */
533 Datum
pg_size_pretty(PG_FUNCTION_ARGS)534 pg_size_pretty(PG_FUNCTION_ARGS)
535 {
536 int64 size = PG_GETARG_INT64(0);
537 char buf[64];
538 int64 limit = 10 * 1024;
539 int64 limit2 = limit * 2 - 1;
540
541 if (Abs(size) < limit)
542 snprintf(buf, sizeof(buf), INT64_FORMAT " bytes", size);
543 else
544 {
545 /*
546 * We use divide instead of bit shifting so that behavior matches for
547 * both positive and negative size values.
548 */
549 size /= (1 << 9); /* keep one extra bit for rounding */
550 if (Abs(size) < limit2)
551 snprintf(buf, sizeof(buf), INT64_FORMAT " kB",
552 half_rounded(size));
553 else
554 {
555 size /= (1 << 10);
556 if (Abs(size) < limit2)
557 snprintf(buf, sizeof(buf), INT64_FORMAT " MB",
558 half_rounded(size));
559 else
560 {
561 size /= (1 << 10);
562 if (Abs(size) < limit2)
563 snprintf(buf, sizeof(buf), INT64_FORMAT " GB",
564 half_rounded(size));
565 else
566 {
567 size /= (1 << 10);
568 snprintf(buf, sizeof(buf), INT64_FORMAT " TB",
569 half_rounded(size));
570 }
571 }
572 }
573 }
574
575 PG_RETURN_TEXT_P(cstring_to_text(buf));
576 }
577
578 static char *
numeric_to_cstring(Numeric n)579 numeric_to_cstring(Numeric n)
580 {
581 Datum d = NumericGetDatum(n);
582
583 return DatumGetCString(DirectFunctionCall1(numeric_out, d));
584 }
585
586 static bool
numeric_is_less(Numeric a,Numeric b)587 numeric_is_less(Numeric a, Numeric b)
588 {
589 Datum da = NumericGetDatum(a);
590 Datum db = NumericGetDatum(b);
591
592 return DatumGetBool(DirectFunctionCall2(numeric_lt, da, db));
593 }
594
595 static Numeric
numeric_absolute(Numeric n)596 numeric_absolute(Numeric n)
597 {
598 Datum d = NumericGetDatum(n);
599 Datum result;
600
601 result = DirectFunctionCall1(numeric_abs, d);
602 return DatumGetNumeric(result);
603 }
604
605 static Numeric
numeric_half_rounded(Numeric n)606 numeric_half_rounded(Numeric n)
607 {
608 Datum d = NumericGetDatum(n);
609 Datum zero;
610 Datum one;
611 Datum two;
612 Datum result;
613
614 zero = NumericGetDatum(int64_to_numeric(0));
615 one = NumericGetDatum(int64_to_numeric(1));
616 two = NumericGetDatum(int64_to_numeric(2));
617
618 if (DatumGetBool(DirectFunctionCall2(numeric_ge, d, zero)))
619 d = DirectFunctionCall2(numeric_add, d, one);
620 else
621 d = DirectFunctionCall2(numeric_sub, d, one);
622
623 result = DirectFunctionCall2(numeric_div_trunc, d, two);
624 return DatumGetNumeric(result);
625 }
626
627 static Numeric
numeric_truncated_divide(Numeric n,int64 divisor)628 numeric_truncated_divide(Numeric n, int64 divisor)
629 {
630 Datum d = NumericGetDatum(n);
631 Datum divisor_numeric;
632 Datum result;
633
634 divisor_numeric = NumericGetDatum(int64_to_numeric(divisor));
635 result = DirectFunctionCall2(numeric_div_trunc, d, divisor_numeric);
636 return DatumGetNumeric(result);
637 }
638
639 Datum
pg_size_pretty_numeric(PG_FUNCTION_ARGS)640 pg_size_pretty_numeric(PG_FUNCTION_ARGS)
641 {
642 Numeric size = PG_GETARG_NUMERIC(0);
643 Numeric limit,
644 limit2;
645 char *result;
646
647 limit = int64_to_numeric(10 * 1024);
648 limit2 = int64_to_numeric(10 * 1024 * 2 - 1);
649
650 if (numeric_is_less(numeric_absolute(size), limit))
651 {
652 result = psprintf("%s bytes", numeric_to_cstring(size));
653 }
654 else
655 {
656 /* keep one extra bit for rounding */
657 /* size /= (1 << 9) */
658 size = numeric_truncated_divide(size, 1 << 9);
659
660 if (numeric_is_less(numeric_absolute(size), limit2))
661 {
662 size = numeric_half_rounded(size);
663 result = psprintf("%s kB", numeric_to_cstring(size));
664 }
665 else
666 {
667 /* size /= (1 << 10) */
668 size = numeric_truncated_divide(size, 1 << 10);
669
670 if (numeric_is_less(numeric_absolute(size), limit2))
671 {
672 size = numeric_half_rounded(size);
673 result = psprintf("%s MB", numeric_to_cstring(size));
674 }
675 else
676 {
677 /* size /= (1 << 10) */
678 size = numeric_truncated_divide(size, 1 << 10);
679
680 if (numeric_is_less(numeric_absolute(size), limit2))
681 {
682 size = numeric_half_rounded(size);
683 result = psprintf("%s GB", numeric_to_cstring(size));
684 }
685 else
686 {
687 /* size /= (1 << 10) */
688 size = numeric_truncated_divide(size, 1 << 10);
689 size = numeric_half_rounded(size);
690 result = psprintf("%s TB", numeric_to_cstring(size));
691 }
692 }
693 }
694 }
695
696 PG_RETURN_TEXT_P(cstring_to_text(result));
697 }
698
699 /*
700 * Convert a human-readable size to a size in bytes
701 */
702 Datum
pg_size_bytes(PG_FUNCTION_ARGS)703 pg_size_bytes(PG_FUNCTION_ARGS)
704 {
705 text *arg = PG_GETARG_TEXT_PP(0);
706 char *str,
707 *strptr,
708 *endptr;
709 char saved_char;
710 Numeric num;
711 int64 result;
712 bool have_digits = false;
713
714 str = text_to_cstring(arg);
715
716 /* Skip leading whitespace */
717 strptr = str;
718 while (isspace((unsigned char) *strptr))
719 strptr++;
720
721 /* Check that we have a valid number and determine where it ends */
722 endptr = strptr;
723
724 /* Part (1): sign */
725 if (*endptr == '-' || *endptr == '+')
726 endptr++;
727
728 /* Part (2): main digit string */
729 if (isdigit((unsigned char) *endptr))
730 {
731 have_digits = true;
732 do
733 endptr++;
734 while (isdigit((unsigned char) *endptr));
735 }
736
737 /* Part (3): optional decimal point and fractional digits */
738 if (*endptr == '.')
739 {
740 endptr++;
741 if (isdigit((unsigned char) *endptr))
742 {
743 have_digits = true;
744 do
745 endptr++;
746 while (isdigit((unsigned char) *endptr));
747 }
748 }
749
750 /* Complain if we don't have a valid number at this point */
751 if (!have_digits)
752 ereport(ERROR,
753 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
754 errmsg("invalid size: \"%s\"", str)));
755
756 /* Part (4): optional exponent */
757 if (*endptr == 'e' || *endptr == 'E')
758 {
759 long exponent;
760 char *cp;
761
762 /*
763 * Note we might one day support EB units, so if what follows 'E'
764 * isn't a number, just treat it all as a unit to be parsed.
765 */
766 exponent = strtol(endptr + 1, &cp, 10);
767 (void) exponent; /* Silence -Wunused-result warnings */
768 if (cp > endptr + 1)
769 endptr = cp;
770 }
771
772 /*
773 * Parse the number, saving the next character, which may be the first
774 * character of the unit string.
775 */
776 saved_char = *endptr;
777 *endptr = '\0';
778
779 num = DatumGetNumeric(DirectFunctionCall3(numeric_in,
780 CStringGetDatum(strptr),
781 ObjectIdGetDatum(InvalidOid),
782 Int32GetDatum(-1)));
783
784 *endptr = saved_char;
785
786 /* Skip whitespace between number and unit */
787 strptr = endptr;
788 while (isspace((unsigned char) *strptr))
789 strptr++;
790
791 /* Handle possible unit */
792 if (*strptr != '\0')
793 {
794 int64 multiplier = 0;
795
796 /* Trim any trailing whitespace */
797 endptr = str + VARSIZE_ANY_EXHDR(arg) - 1;
798
799 while (isspace((unsigned char) *endptr))
800 endptr--;
801
802 endptr++;
803 *endptr = '\0';
804
805 /* Parse the unit case-insensitively */
806 if (pg_strcasecmp(strptr, "bytes") == 0)
807 multiplier = (int64) 1;
808 else if (pg_strcasecmp(strptr, "kb") == 0)
809 multiplier = (int64) 1024;
810 else if (pg_strcasecmp(strptr, "mb") == 0)
811 multiplier = ((int64) 1024) * 1024;
812
813 else if (pg_strcasecmp(strptr, "gb") == 0)
814 multiplier = ((int64) 1024) * 1024 * 1024;
815
816 else if (pg_strcasecmp(strptr, "tb") == 0)
817 multiplier = ((int64) 1024) * 1024 * 1024 * 1024;
818
819 else
820 ereport(ERROR,
821 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
822 errmsg("invalid size: \"%s\"", text_to_cstring(arg)),
823 errdetail("Invalid size unit: \"%s\".", strptr),
824 errhint("Valid units are \"bytes\", \"kB\", \"MB\", \"GB\", and \"TB\".")));
825
826 if (multiplier > 1)
827 {
828 Numeric mul_num;
829
830 mul_num = int64_to_numeric(multiplier);
831
832 num = DatumGetNumeric(DirectFunctionCall2(numeric_mul,
833 NumericGetDatum(mul_num),
834 NumericGetDatum(num)));
835 }
836 }
837
838 result = DatumGetInt64(DirectFunctionCall1(numeric_int8,
839 NumericGetDatum(num)));
840
841 PG_RETURN_INT64(result);
842 }
843
844 /*
845 * Get the filenode of a relation
846 *
847 * This is expected to be used in queries like
848 * SELECT pg_relation_filenode(oid) FROM pg_class;
849 * That leads to a couple of choices. We work from the pg_class row alone
850 * rather than actually opening each relation, for efficiency. We don't
851 * fail if we can't find the relation --- some rows might be visible in
852 * the query's MVCC snapshot even though the relations have been dropped.
853 * (Note: we could avoid using the catcache, but there's little point
854 * because the relation mapper also works "in the now".) We also don't
855 * fail if the relation doesn't have storage. In all these cases it
856 * seems better to quietly return NULL.
857 */
858 Datum
pg_relation_filenode(PG_FUNCTION_ARGS)859 pg_relation_filenode(PG_FUNCTION_ARGS)
860 {
861 Oid relid = PG_GETARG_OID(0);
862 Oid result;
863 HeapTuple tuple;
864 Form_pg_class relform;
865
866 tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relid));
867 if (!HeapTupleIsValid(tuple))
868 PG_RETURN_NULL();
869 relform = (Form_pg_class) GETSTRUCT(tuple);
870
871 if (RELKIND_HAS_STORAGE(relform->relkind))
872 {
873 if (relform->relfilenode)
874 result = relform->relfilenode;
875 else /* Consult the relation mapper */
876 result = RelationMapOidToFilenode(relid,
877 relform->relisshared);
878 }
879 else
880 {
881 /* no storage, return NULL */
882 result = InvalidOid;
883 }
884
885 ReleaseSysCache(tuple);
886
887 if (!OidIsValid(result))
888 PG_RETURN_NULL();
889
890 PG_RETURN_OID(result);
891 }
892
893 /*
894 * Get the relation via (reltablespace, relfilenode)
895 *
896 * This is expected to be used when somebody wants to match an individual file
897 * on the filesystem back to its table. That's not trivially possible via
898 * pg_class, because that doesn't contain the relfilenodes of shared and nailed
899 * tables.
900 *
901 * We don't fail but return NULL if we cannot find a mapping.
902 *
903 * InvalidOid can be passed instead of the current database's default
904 * tablespace.
905 */
906 Datum
pg_filenode_relation(PG_FUNCTION_ARGS)907 pg_filenode_relation(PG_FUNCTION_ARGS)
908 {
909 Oid reltablespace = PG_GETARG_OID(0);
910 Oid relfilenode = PG_GETARG_OID(1);
911 Oid heaprel;
912
913 /* test needed so RelidByRelfilenode doesn't misbehave */
914 if (!OidIsValid(relfilenode))
915 PG_RETURN_NULL();
916
917 heaprel = RelidByRelfilenode(reltablespace, relfilenode);
918
919 if (!OidIsValid(heaprel))
920 PG_RETURN_NULL();
921 else
922 PG_RETURN_OID(heaprel);
923 }
924
925 /*
926 * Get the pathname (relative to $PGDATA) of a relation
927 *
928 * See comments for pg_relation_filenode.
929 */
930 Datum
pg_relation_filepath(PG_FUNCTION_ARGS)931 pg_relation_filepath(PG_FUNCTION_ARGS)
932 {
933 Oid relid = PG_GETARG_OID(0);
934 HeapTuple tuple;
935 Form_pg_class relform;
936 RelFileNode rnode;
937 BackendId backend;
938 char *path;
939
940 tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relid));
941 if (!HeapTupleIsValid(tuple))
942 PG_RETURN_NULL();
943 relform = (Form_pg_class) GETSTRUCT(tuple);
944
945 if (RELKIND_HAS_STORAGE(relform->relkind))
946 {
947 /* This logic should match RelationInitPhysicalAddr */
948 if (relform->reltablespace)
949 rnode.spcNode = relform->reltablespace;
950 else
951 rnode.spcNode = MyDatabaseTableSpace;
952 if (rnode.spcNode == GLOBALTABLESPACE_OID)
953 rnode.dbNode = InvalidOid;
954 else
955 rnode.dbNode = MyDatabaseId;
956 if (relform->relfilenode)
957 rnode.relNode = relform->relfilenode;
958 else /* Consult the relation mapper */
959 rnode.relNode = RelationMapOidToFilenode(relid,
960 relform->relisshared);
961 }
962 else
963 {
964 /* no storage, return NULL */
965 rnode.relNode = InvalidOid;
966 /* some compilers generate warnings without these next two lines */
967 rnode.dbNode = InvalidOid;
968 rnode.spcNode = InvalidOid;
969 }
970
971 if (!OidIsValid(rnode.relNode))
972 {
973 ReleaseSysCache(tuple);
974 PG_RETURN_NULL();
975 }
976
977 /* Determine owning backend. */
978 switch (relform->relpersistence)
979 {
980 case RELPERSISTENCE_UNLOGGED:
981 case RELPERSISTENCE_PERMANENT:
982 backend = InvalidBackendId;
983 break;
984 case RELPERSISTENCE_TEMP:
985 if (isTempOrTempToastNamespace(relform->relnamespace))
986 backend = BackendIdForTempRelations();
987 else
988 {
989 /* Do it the hard way. */
990 backend = GetTempNamespaceBackendId(relform->relnamespace);
991 Assert(backend != InvalidBackendId);
992 }
993 break;
994 default:
995 elog(ERROR, "invalid relpersistence: %c", relform->relpersistence);
996 backend = InvalidBackendId; /* placate compiler */
997 break;
998 }
999
1000 ReleaseSysCache(tuple);
1001
1002 path = relpathbackend(rnode, backend, MAIN_FORKNUM);
1003
1004 PG_RETURN_TEXT_P(cstring_to_text(path));
1005 }
1006