Line data Source code
1 : /*
2 : * brin_tuple.c
3 : * Method implementations for tuples in BRIN indexes.
4 : *
5 : * Intended usage is that code outside this file only deals with
6 : * BrinMemTuples, and convert to and from the on-disk representation through
7 : * functions in this file.
8 : *
9 : * NOTES
10 : *
11 : * A BRIN tuple is similar to a heap tuple, with a few key differences. The
12 : * first interesting difference is that the tuple header is much simpler, only
13 : * containing its total length and a small area for flags. Also, the stored
14 : * data does not match the relation tuple descriptor exactly: for each
15 : * attribute in the descriptor, the index tuple carries an arbitrary number
16 : * of values, depending on the opclass.
17 : *
18 : * Also, for each column of the index relation there are two null bits: one
19 : * (hasnulls) stores whether any tuple within the page range has that column
20 : * set to null; the other one (allnulls) stores whether the column values are
21 : * all null. If allnulls is true, then the tuple data area does not contain
22 : * values for that column at all; whereas it does if the hasnulls is set.
23 : * Note the size of the null bitmask may not be the same as that of the
24 : * datum array.
25 : *
26 : * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
27 : * Portions Copyright (c) 1994, Regents of the University of California
28 : *
29 : * IDENTIFICATION
30 : * src/backend/access/brin/brin_tuple.c
31 : */
32 : #include "postgres.h"
33 :
34 : #include "access/brin_tuple.h"
35 : #include "access/detoast.h"
36 : #include "access/heaptoast.h"
37 : #include "access/htup_details.h"
38 : #include "access/toast_internals.h"
39 : #include "access/tupdesc.h"
40 : #include "access/tupmacs.h"
41 : #include "utils/datum.h"
42 : #include "utils/memutils.h"
43 :
44 :
45 : /*
46 : * This enables de-toasting of index entries. Needed until VACUUM is
47 : * smart enough to rebuild indexes from scratch.
48 : */
49 : #define TOAST_INDEX_HACK
50 :
51 :
52 : static inline void brin_deconstruct_tuple(BrinDesc *brdesc,
53 : char *tp, bits8 *nullbits, bool nulls,
54 : Datum *values, bool *allnulls, bool *hasnulls);
55 :
56 :
57 : /*
58 : * Return a tuple descriptor used for on-disk storage of BRIN tuples.
59 : */
60 : static TupleDesc
61 148780 : brtuple_disk_tupdesc(BrinDesc *brdesc)
62 : {
63 : /* We cache these in the BrinDesc */
64 148780 : if (brdesc->bd_disktdesc == NULL)
65 : {
66 : int i;
67 : int j;
68 2264 : AttrNumber attno = 1;
69 : TupleDesc tupdesc;
70 : MemoryContext oldcxt;
71 :
72 : /* make sure it's in the bdesc's context */
73 2264 : oldcxt = MemoryContextSwitchTo(brdesc->bd_context);
74 :
75 2264 : tupdesc = CreateTemplateTupleDesc(brdesc->bd_totalstored);
76 :
77 37812 : for (i = 0; i < brdesc->bd_tupdesc->natts; i++)
78 : {
79 97672 : for (j = 0; j < brdesc->bd_info[i]->oi_nstored; j++)
80 62124 : TupleDescInitEntry(tupdesc, attno++, NULL,
81 62124 : brdesc->bd_info[i]->oi_typcache[j]->type_id,
82 : -1, 0);
83 : }
84 :
85 2264 : MemoryContextSwitchTo(oldcxt);
86 :
87 2264 : brdesc->bd_disktdesc = tupdesc;
88 : }
89 :
90 148780 : return brdesc->bd_disktdesc;
91 : }
92 :
93 : /*
94 : * Generate a new on-disk tuple to be inserted in a BRIN index.
95 : *
96 : * See brin_form_placeholder_tuple if you touch this.
97 : */
98 : BrinTuple *
99 14813 : brin_form_tuple(BrinDesc *brdesc, BlockNumber blkno, BrinMemTuple *tuple,
100 : Size *size)
101 : {
102 : Datum *values;
103 : bool *nulls;
104 14813 : bool anynulls = false;
105 : BrinTuple *rettuple;
106 : int keyno;
107 : int idxattno;
108 14813 : uint16 phony_infomask = 0;
109 : bits8 *phony_nullbitmap;
110 : Size len,
111 : hoff,
112 : data_len;
113 : int i;
114 :
115 : #ifdef TOAST_INDEX_HACK
116 : Datum *untoasted_values;
117 14813 : int nuntoasted = 0;
118 : #endif
119 :
120 : Assert(brdesc->bd_totalstored > 0);
121 :
122 14813 : values = palloc_array(Datum, brdesc->bd_totalstored);
123 14813 : nulls = palloc0_array(bool, brdesc->bd_totalstored);
124 14813 : phony_nullbitmap = palloc_array(bits8, BITMAPLEN(brdesc->bd_totalstored));
125 :
126 : #ifdef TOAST_INDEX_HACK
127 14813 : untoasted_values = palloc_array(Datum, brdesc->bd_totalstored);
128 : #endif
129 :
130 : /*
131 : * Set up the values/nulls arrays for heap_fill_tuple
132 : */
133 14813 : idxattno = 0;
134 100296 : for (keyno = 0; keyno < brdesc->bd_tupdesc->natts; keyno++)
135 : {
136 : int datumno;
137 :
138 : /*
139 : * "allnulls" is set when there's no nonnull value in any row in the
140 : * column; when this happens, there is no data to store. Thus set the
141 : * nullable bits for all data elements of this column and we're done.
142 : */
143 85483 : if (tuple->bt_columns[keyno].bv_allnulls)
144 : {
145 362 : for (datumno = 0;
146 834 : datumno < brdesc->bd_info[keyno]->oi_nstored;
147 472 : datumno++)
148 472 : nulls[idxattno++] = true;
149 362 : anynulls = true;
150 362 : continue;
151 : }
152 :
153 : /*
154 : * The "hasnulls" bit is set when there are some null values in the
155 : * data. We still need to store a real value, but the presence of
156 : * this means we need a null bitmap.
157 : */
158 85121 : if (tuple->bt_columns[keyno].bv_hasnulls)
159 4951 : anynulls = true;
160 :
161 : /* If needed, serialize the values before forming the on-disk tuple. */
162 85121 : if (tuple->bt_columns[keyno].bv_serialize)
163 : {
164 9033 : tuple->bt_columns[keyno].bv_serialize(brdesc,
165 : tuple->bt_columns[keyno].bv_mem_value,
166 : tuple->bt_columns[keyno].bv_values);
167 : }
168 :
169 : /*
170 : * Now obtain the values of each stored datum. Note that some values
171 : * might be toasted, and we cannot rely on the original heap values
172 : * sticking around forever, so we must detoast them. Also try to
173 : * compress them.
174 : */
175 85121 : for (datumno = 0;
176 234963 : datumno < brdesc->bd_info[keyno]->oi_nstored;
177 149842 : datumno++)
178 : {
179 149842 : Datum value = tuple->bt_columns[keyno].bv_values[datumno];
180 :
181 : #ifdef TOAST_INDEX_HACK
182 :
183 : /* We must look at the stored type, not at the index descriptor. */
184 149842 : TypeCacheEntry *atttype = brdesc->bd_info[keyno]->oi_typcache[datumno];
185 :
186 : /* Do we need to free the value at the end? */
187 149842 : bool free_value = false;
188 :
189 : /* For non-varlena types we don't need to do anything special */
190 149842 : if (atttype->typlen != -1)
191 : {
192 67327 : values[idxattno++] = value;
193 67327 : continue;
194 : }
195 :
196 : /*
197 : * Do nothing if value is not of varlena type. We don't need to
198 : * care about NULL values here, thanks to bv_allnulls above.
199 : *
200 : * If value is stored EXTERNAL, must fetch it so we are not
201 : * depending on outside storage.
202 : *
203 : * XXX Is this actually true? Could it be that the summary is NULL
204 : * even for range with non-NULL data? E.g. degenerate bloom filter
205 : * may be thrown away, etc.
206 : */
207 82515 : if (VARATT_IS_EXTERNAL(DatumGetPointer(value)))
208 : {
209 12 : value = PointerGetDatum(detoast_external_attr((varlena *)
210 12 : DatumGetPointer(value)));
211 12 : free_value = true;
212 : }
213 :
214 : /*
215 : * If value is above size target, and is of a compressible
216 : * datatype, try to compress it in-line.
217 : */
218 106820 : if (!VARATT_IS_EXTENDED(DatumGetPointer(value)) &&
219 24305 : VARSIZE(DatumGetPointer(value)) > TOAST_INDEX_TARGET &&
220 30 : (atttype->typstorage == TYPSTORAGE_EXTENDED ||
221 0 : atttype->typstorage == TYPSTORAGE_MAIN))
222 : {
223 : Datum cvalue;
224 : char compression;
225 30 : Form_pg_attribute att = TupleDescAttr(brdesc->bd_tupdesc,
226 : keyno);
227 :
228 : /*
229 : * If the BRIN summary and indexed attribute use the same data
230 : * type and it has a valid compression method, we can use the
231 : * same compression method. Otherwise we have to use the
232 : * default method.
233 : */
234 30 : if (att->atttypid == atttype->type_id)
235 24 : compression = att->attcompression;
236 : else
237 6 : compression = InvalidCompressionMethod;
238 :
239 30 : cvalue = toast_compress_datum(value, compression);
240 :
241 30 : if (DatumGetPointer(cvalue) != NULL)
242 : {
243 : /* successful compression */
244 6 : if (free_value)
245 0 : pfree(DatumGetPointer(value));
246 :
247 6 : value = cvalue;
248 6 : free_value = true;
249 : }
250 : }
251 :
252 : /*
253 : * If we untoasted / compressed the value, we need to free it
254 : * after forming the index tuple.
255 : */
256 82515 : if (free_value)
257 18 : untoasted_values[nuntoasted++] = value;
258 :
259 : #endif
260 :
261 82515 : values[idxattno++] = value;
262 : }
263 : }
264 :
265 : /* Assert we did not overrun temp arrays */
266 : Assert(idxattno <= brdesc->bd_totalstored);
267 :
268 : /* compute total space needed */
269 14813 : len = SizeOfBrinTuple;
270 14813 : if (anynulls)
271 : {
272 : /*
273 : * We need a double-length bitmap on an on-disk BRIN index tuple; the
274 : * first half stores the "allnulls" bits, the second stores
275 : * "hasnulls".
276 : */
277 396 : len += BITMAPLEN(brdesc->bd_tupdesc->natts * 2);
278 : }
279 :
280 14813 : len = hoff = MAXALIGN(len);
281 :
282 14813 : data_len = heap_compute_data_size(brtuple_disk_tupdesc(brdesc),
283 : values, nulls);
284 14813 : len += data_len;
285 :
286 14813 : len = MAXALIGN(len);
287 :
288 14813 : rettuple = palloc0(len);
289 14813 : rettuple->bt_blkno = blkno;
290 14813 : rettuple->bt_info = hoff;
291 :
292 : /* Assert that hoff fits in the space available */
293 : Assert((rettuple->bt_info & BRIN_OFFSET_MASK) == hoff);
294 :
295 : /*
296 : * The infomask and null bitmap as computed by heap_fill_tuple are useless
297 : * to us. However, that function will not accept a null infomask; and we
298 : * need to pass a valid null bitmap so that it will correctly skip
299 : * outputting null attributes in the data area.
300 : */
301 14813 : heap_fill_tuple(brtuple_disk_tupdesc(brdesc),
302 : values,
303 : nulls,
304 : (char *) rettuple + hoff,
305 : data_len,
306 : &phony_infomask,
307 : phony_nullbitmap);
308 :
309 : /* done with these */
310 14813 : pfree(values);
311 14813 : pfree(nulls);
312 14813 : pfree(phony_nullbitmap);
313 :
314 : #ifdef TOAST_INDEX_HACK
315 14831 : for (i = 0; i < nuntoasted; i++)
316 18 : pfree(DatumGetPointer(untoasted_values[i]));
317 : #endif
318 :
319 : /*
320 : * Now fill in the real null bitmasks. allnulls first.
321 : */
322 14813 : if (anynulls)
323 : {
324 : bits8 *bitP;
325 : int bitmask;
326 :
327 396 : rettuple->bt_info |= BRIN_NULLS_MASK;
328 :
329 : /*
330 : * Note that we reverse the sense of null bits in this module: we
331 : * store a 1 for a null attribute rather than a 0. So we must reverse
332 : * the sense of the att_isnull test in brin_deconstruct_tuple as well.
333 : */
334 396 : bitP = ((bits8 *) ((char *) rettuple + SizeOfBrinTuple)) - 1;
335 396 : bitmask = HIGHBIT;
336 6518 : for (keyno = 0; keyno < brdesc->bd_tupdesc->natts; keyno++)
337 : {
338 6122 : if (bitmask != HIGHBIT)
339 5154 : bitmask <<= 1;
340 : else
341 : {
342 968 : bitP += 1;
343 968 : *bitP = 0x0;
344 968 : bitmask = 1;
345 : }
346 :
347 6122 : if (!tuple->bt_columns[keyno].bv_allnulls)
348 5760 : continue;
349 :
350 362 : *bitP |= bitmask;
351 : }
352 : /* hasnulls bits follow */
353 6518 : for (keyno = 0; keyno < brdesc->bd_tupdesc->natts; keyno++)
354 : {
355 6122 : if (bitmask != HIGHBIT)
356 5470 : bitmask <<= 1;
357 : else
358 : {
359 652 : bitP += 1;
360 652 : *bitP = 0x0;
361 652 : bitmask = 1;
362 : }
363 :
364 6122 : if (!tuple->bt_columns[keyno].bv_hasnulls)
365 977 : continue;
366 :
367 5145 : *bitP |= bitmask;
368 : }
369 : }
370 :
371 14813 : if (tuple->bt_placeholder)
372 0 : rettuple->bt_info |= BRIN_PLACEHOLDER_MASK;
373 :
374 14813 : if (tuple->bt_empty_range)
375 74 : rettuple->bt_info |= BRIN_EMPTY_RANGE_MASK;
376 :
377 14813 : *size = len;
378 14813 : return rettuple;
379 : }
380 :
381 : /*
382 : * Generate a new on-disk tuple with no data values, marked as placeholder.
383 : *
384 : * This is a cut-down version of brin_form_tuple.
385 : */
386 : BrinTuple *
387 1474 : brin_form_placeholder_tuple(BrinDesc *brdesc, BlockNumber blkno, Size *size)
388 : {
389 : Size len;
390 : Size hoff;
391 : BrinTuple *rettuple;
392 : int keyno;
393 : bits8 *bitP;
394 : int bitmask;
395 :
396 : /* compute total space needed: always add nulls */
397 1474 : len = SizeOfBrinTuple;
398 1474 : len += BITMAPLEN(brdesc->bd_tupdesc->natts * 2);
399 1474 : len = hoff = MAXALIGN(len);
400 :
401 1474 : rettuple = palloc0(len);
402 1474 : rettuple->bt_blkno = blkno;
403 1474 : rettuple->bt_info = hoff;
404 1474 : rettuple->bt_info |= BRIN_NULLS_MASK | BRIN_PLACEHOLDER_MASK | BRIN_EMPTY_RANGE_MASK;
405 :
406 1474 : bitP = ((bits8 *) ((char *) rettuple + SizeOfBrinTuple)) - 1;
407 1474 : bitmask = HIGHBIT;
408 : /* set allnulls true for all attributes */
409 4206 : for (keyno = 0; keyno < brdesc->bd_tupdesc->natts; keyno++)
410 : {
411 2732 : if (bitmask != HIGHBIT)
412 1133 : bitmask <<= 1;
413 : else
414 : {
415 1599 : bitP += 1;
416 1599 : *bitP = 0x0;
417 1599 : bitmask = 1;
418 : }
419 :
420 2732 : *bitP |= bitmask;
421 : }
422 : /* no need to set hasnulls */
423 :
424 1474 : *size = len;
425 1474 : return rettuple;
426 : }
427 :
428 : /*
429 : * Free a tuple created by brin_form_tuple
430 : */
431 : void
432 2948 : brin_free_tuple(BrinTuple *tuple)
433 : {
434 2948 : pfree(tuple);
435 2948 : }
436 :
437 : /*
438 : * Given a brin tuple of size len, create a copy of it. If 'dest' is not
439 : * NULL, its size is destsz, and can be used as output buffer; if the tuple
440 : * to be copied does not fit, it is enlarged by repalloc, and the size is
441 : * updated to match. This avoids palloc/free cycles when many brin tuples
442 : * are being processed in loops.
443 : */
444 : BrinTuple *
445 107223 : brin_copy_tuple(BrinTuple *tuple, Size len, BrinTuple *dest, Size *destsz)
446 : {
447 107223 : if (!destsz || *destsz == 0)
448 107223 : dest = palloc(len);
449 0 : else if (len > *destsz)
450 : {
451 0 : dest = repalloc(dest, len);
452 0 : *destsz = len;
453 : }
454 :
455 107223 : memcpy(dest, tuple, len);
456 :
457 107223 : return dest;
458 : }
459 :
460 : /*
461 : * Return whether two BrinTuples are bitwise identical.
462 : */
463 : bool
464 13729 : brin_tuples_equal(const BrinTuple *a, Size alen, const BrinTuple *b, Size blen)
465 : {
466 13729 : if (alen != blen)
467 0 : return false;
468 13729 : if (memcmp(a, b, alen) != 0)
469 0 : return false;
470 13729 : return true;
471 : }
472 :
473 : /*
474 : * Create a new BrinMemTuple from scratch, and initialize it to an empty
475 : * state.
476 : *
477 : * Note: we don't provide any means to free a deformed tuple, so make sure to
478 : * use a temporary memory context.
479 : */
480 : BrinMemTuple *
481 25884 : brin_new_memtuple(BrinDesc *brdesc)
482 : {
483 : BrinMemTuple *dtup;
484 : long basesize;
485 :
486 25884 : basesize = MAXALIGN(sizeof(BrinMemTuple) +
487 : sizeof(BrinValues) * brdesc->bd_tupdesc->natts);
488 25884 : dtup = palloc0(basesize + sizeof(Datum) * brdesc->bd_totalstored);
489 :
490 25884 : dtup->bt_values = palloc_array(Datum, brdesc->bd_totalstored);
491 25884 : dtup->bt_allnulls = palloc_array(bool, brdesc->bd_tupdesc->natts);
492 25884 : dtup->bt_hasnulls = palloc_array(bool, brdesc->bd_tupdesc->natts);
493 :
494 25884 : dtup->bt_empty_range = true;
495 :
496 25884 : dtup->bt_context = AllocSetContextCreate(CurrentMemoryContext,
497 : "brin dtuple",
498 : ALLOCSET_DEFAULT_SIZES);
499 :
500 25884 : brin_memtuple_initialize(dtup, brdesc);
501 :
502 25884 : return dtup;
503 : }
504 :
505 : /*
506 : * Reset a BrinMemTuple to initial state. We return the same tuple, for
507 : * notational convenience.
508 : */
509 : BrinMemTuple *
510 123515 : brin_memtuple_initialize(BrinMemTuple *dtuple, BrinDesc *brdesc)
511 : {
512 : int i;
513 : char *currdatum;
514 :
515 123515 : MemoryContextReset(dtuple->bt_context);
516 :
517 123515 : currdatum = (char *) dtuple +
518 123515 : MAXALIGN(sizeof(BrinMemTuple) +
519 : sizeof(BrinValues) * brdesc->bd_tupdesc->natts);
520 2905089 : for (i = 0; i < brdesc->bd_tupdesc->natts; i++)
521 : {
522 2781574 : dtuple->bt_columns[i].bv_attno = i + 1;
523 2781574 : dtuple->bt_columns[i].bv_allnulls = true;
524 2781574 : dtuple->bt_columns[i].bv_hasnulls = false;
525 2781574 : dtuple->bt_columns[i].bv_values = (Datum *) currdatum;
526 :
527 2781574 : dtuple->bt_columns[i].bv_mem_value = PointerGetDatum(NULL);
528 2781574 : dtuple->bt_columns[i].bv_serialize = NULL;
529 2781574 : dtuple->bt_columns[i].bv_context = dtuple->bt_context;
530 :
531 2781574 : currdatum += sizeof(Datum) * brdesc->bd_info[i]->oi_nstored;
532 : }
533 :
534 123515 : dtuple->bt_empty_range = true;
535 :
536 123515 : return dtuple;
537 : }
538 :
539 : /*
540 : * Convert a BrinTuple back to a BrinMemTuple. This is the reverse of
541 : * brin_form_tuple.
542 : *
543 : * As an optimization, the caller can pass a previously allocated 'dMemtuple'.
544 : * This avoids having to allocate it here, which can be useful when this
545 : * function is called many times in a loop. It is caller's responsibility
546 : * that the given BrinMemTuple matches what we need here.
547 : *
548 : * Note we don't need the "on disk tupdesc" here; we rely on our own routine to
549 : * deconstruct the tuple from the on-disk format.
550 : */
551 : BrinMemTuple *
552 119154 : brin_deform_tuple(BrinDesc *brdesc, BrinTuple *tuple, BrinMemTuple *dMemtuple)
553 : {
554 : BrinMemTuple *dtup;
555 : Datum *values;
556 : bool *allnulls;
557 : bool *hasnulls;
558 : char *tp;
559 : bits8 *nullbits;
560 : int keyno;
561 : int valueno;
562 : MemoryContext oldcxt;
563 :
564 119154 : dtup = dMemtuple ? brin_memtuple_initialize(dMemtuple, brdesc) :
565 24166 : brin_new_memtuple(brdesc);
566 :
567 119154 : if (BrinTupleIsPlaceholder(tuple))
568 0 : dtup->bt_placeholder = true;
569 :
570 : /* ranges start as empty, depends on the BrinTuple */
571 119154 : if (!BrinTupleIsEmptyRange(tuple))
572 119079 : dtup->bt_empty_range = false;
573 :
574 119154 : dtup->bt_blkno = tuple->bt_blkno;
575 :
576 119154 : values = dtup->bt_values;
577 119154 : allnulls = dtup->bt_allnulls;
578 119154 : hasnulls = dtup->bt_hasnulls;
579 :
580 119154 : tp = (char *) tuple + BrinTupleDataOffset(tuple);
581 :
582 119154 : if (BrinTupleHasNulls(tuple))
583 11735 : nullbits = (bits8 *) ((char *) tuple + SizeOfBrinTuple);
584 : else
585 107419 : nullbits = NULL;
586 119154 : brin_deconstruct_tuple(brdesc,
587 119154 : tp, nullbits, BrinTupleHasNulls(tuple),
588 : values, allnulls, hasnulls);
589 :
590 : /*
591 : * Iterate to assign each of the values to the corresponding item in the
592 : * values array of each column. The copies occur in the tuple's context.
593 : */
594 119154 : oldcxt = MemoryContextSwitchTo(dtup->bt_context);
595 2848257 : for (valueno = 0, keyno = 0; keyno < brdesc->bd_tupdesc->natts; keyno++)
596 : {
597 : int i;
598 :
599 2729103 : if (allnulls[keyno])
600 : {
601 5641 : valueno += brdesc->bd_info[keyno]->oi_nstored;
602 5641 : continue;
603 : }
604 :
605 : /*
606 : * We would like to skip datumCopy'ing the values datum in some cases,
607 : * caller permitting ...
608 : */
609 8049894 : for (i = 0; i < brdesc->bd_info[keyno]->oi_nstored; i++)
610 5326432 : dtup->bt_columns[keyno].bv_values[i] =
611 5326432 : datumCopy(values[valueno++],
612 5326432 : brdesc->bd_info[keyno]->oi_typcache[i]->typbyval,
613 5326432 : brdesc->bd_info[keyno]->oi_typcache[i]->typlen);
614 :
615 2723462 : dtup->bt_columns[keyno].bv_hasnulls = hasnulls[keyno];
616 2723462 : dtup->bt_columns[keyno].bv_allnulls = false;
617 :
618 2723462 : dtup->bt_columns[keyno].bv_mem_value = PointerGetDatum(NULL);
619 2723462 : dtup->bt_columns[keyno].bv_serialize = NULL;
620 2723462 : dtup->bt_columns[keyno].bv_context = dtup->bt_context;
621 : }
622 :
623 119154 : MemoryContextSwitchTo(oldcxt);
624 :
625 119154 : return dtup;
626 : }
627 :
628 : /*
629 : * brin_deconstruct_tuple
630 : * Guts of attribute extraction from an on-disk BRIN tuple.
631 : *
632 : * Its arguments are:
633 : * brdesc BRIN descriptor for the stored tuple
634 : * tp pointer to the tuple data area
635 : * nullbits pointer to the tuple nulls bitmask
636 : * nulls "has nulls" bit in tuple infomask
637 : * values output values, array of size brdesc->bd_totalstored
638 : * allnulls output "allnulls", size brdesc->bd_tupdesc->natts
639 : * hasnulls output "hasnulls", size brdesc->bd_tupdesc->natts
640 : *
641 : * Output arrays must have been allocated by caller.
642 : */
643 : static inline void
644 119154 : brin_deconstruct_tuple(BrinDesc *brdesc,
645 : char *tp, bits8 *nullbits, bool nulls,
646 : Datum *values, bool *allnulls, bool *hasnulls)
647 : {
648 : int attnum;
649 : int stored;
650 : TupleDesc diskdsc;
651 : long off;
652 :
653 : /*
654 : * First iterate to natts to obtain both null flags for each attribute.
655 : * Note that we reverse the sense of the att_isnull test, because we store
656 : * 1 for a null value (rather than a 1 for a not null value as is the
657 : * att_isnull convention used elsewhere.) See brin_form_tuple.
658 : */
659 2848257 : for (attnum = 0; attnum < brdesc->bd_tupdesc->natts; attnum++)
660 : {
661 : /*
662 : * the "all nulls" bit means that all values in the page range for
663 : * this column are nulls. Therefore there are no values in the tuple
664 : * data area.
665 : */
666 2729103 : allnulls[attnum] = nulls && !att_isnull(attnum, nullbits);
667 :
668 : /*
669 : * the "has nulls" bit means that some tuples have nulls, but others
670 : * have not-null values. Therefore we know the tuple contains data
671 : * for this column.
672 : *
673 : * The hasnulls bits follow the allnulls bits in the same bitmask.
674 : */
675 2729103 : hasnulls[attnum] =
676 2729103 : nulls && !att_isnull(brdesc->bd_tupdesc->natts + attnum, nullbits);
677 : }
678 :
679 : /*
680 : * Iterate to obtain each attribute's stored values. Note that since we
681 : * may reuse attribute entries for more than one column, we cannot cache
682 : * offsets here.
683 : */
684 119154 : diskdsc = brtuple_disk_tupdesc(brdesc);
685 119154 : stored = 0;
686 119154 : off = 0;
687 2848257 : for (attnum = 0; attnum < brdesc->bd_tupdesc->natts; attnum++)
688 : {
689 : int datumno;
690 :
691 2729103 : if (allnulls[attnum])
692 : {
693 5641 : stored += brdesc->bd_info[attnum]->oi_nstored;
694 5641 : continue;
695 : }
696 :
697 2723462 : for (datumno = 0;
698 8049894 : datumno < brdesc->bd_info[attnum]->oi_nstored;
699 5326432 : datumno++)
700 : {
701 5326432 : CompactAttribute *thisatt = TupleDescCompactAttr(diskdsc, stored);
702 :
703 5326432 : if (thisatt->attlen == -1)
704 : {
705 1906590 : off = att_pointer_alignby(off,
706 : thisatt->attalignby,
707 : -1,
708 : tp + off);
709 : }
710 : else
711 : {
712 : /* not varlena, so safe to use att_nominal_alignby */
713 3419842 : off = att_nominal_alignby(off, thisatt->attalignby);
714 : }
715 :
716 5326432 : values[stored++] = fetchatt(thisatt, tp + off);
717 :
718 5326432 : off = att_addlength_pointer(off, thisatt->attlen, tp + off);
719 : }
720 : }
721 119154 : }
|
