Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * expandedrecord.c
4 : * Functions for manipulating composite expanded objects.
5 : *
6 : * This module supports "expanded objects" (cf. expandeddatum.h) that can
7 : * store values of named composite types, domains over named composite types,
8 : * and record types (registered or anonymous).
9 : *
10 : * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
11 : * Portions Copyright (c) 1994, Regents of the University of California
12 : *
13 : *
14 : * IDENTIFICATION
15 : * src/backend/utils/adt/expandedrecord.c
16 : *
17 : *-------------------------------------------------------------------------
18 : */
19 : #include "postgres.h"
20 :
21 : #include "access/detoast.h"
22 : #include "access/heaptoast.h"
23 : #include "access/htup_details.h"
24 : #include "catalog/heap.h"
25 : #include "catalog/pg_type.h"
26 : #include "utils/builtins.h"
27 : #include "utils/datum.h"
28 : #include "utils/expandedrecord.h"
29 : #include "utils/memutils.h"
30 : #include "utils/typcache.h"
31 :
32 :
33 : /* "Methods" required for an expanded object */
34 : static Size ER_get_flat_size(ExpandedObjectHeader *eohptr);
35 : static void ER_flatten_into(ExpandedObjectHeader *eohptr,
36 : void *result, Size allocated_size);
37 :
38 : static const ExpandedObjectMethods ER_methods =
39 : {
40 : ER_get_flat_size,
41 : ER_flatten_into
42 : };
43 :
44 : /* Other local functions */
45 : static void ER_mc_callback(void *arg);
46 : static MemoryContext get_short_term_cxt(ExpandedRecordHeader *erh);
47 : static void build_dummy_expanded_header(ExpandedRecordHeader *main_erh);
48 : static pg_noinline void check_domain_for_new_field(ExpandedRecordHeader *erh,
49 : int fnumber,
50 : Datum newValue, bool isnull);
51 : static pg_noinline void check_domain_for_new_tuple(ExpandedRecordHeader *erh,
52 : HeapTuple tuple);
53 :
54 :
55 : /*
56 : * Build an expanded record of the specified composite type
57 : *
58 : * type_id can be RECORDOID, but only if a positive typmod is given.
59 : *
60 : * The expanded record is initially "empty", having a state logically
61 : * equivalent to a NULL composite value (not ROW(NULL, NULL, ...)).
62 : * Note that this might not be a valid state for a domain type;
63 : * if the caller needs to check that, call
64 : * expanded_record_set_tuple(erh, NULL, false, false).
65 : *
66 : * The expanded object will be a child of parentcontext.
67 : */
68 : ExpandedRecordHeader *
69 654 : make_expanded_record_from_typeid(Oid type_id, int32 typmod,
70 : MemoryContext parentcontext)
71 : {
72 : ExpandedRecordHeader *erh;
73 654 : int flags = 0;
74 : TupleDesc tupdesc;
75 : uint64 tupdesc_id;
76 : MemoryContext objcxt;
77 : char *chunk;
78 :
79 654 : if (type_id != RECORDOID)
80 : {
81 : /*
82 : * Consult the typcache to see if it's a domain over composite, and in
83 : * any case to get the tupdesc and tupdesc identifier.
84 : */
85 : TypeCacheEntry *typentry;
86 :
87 594 : typentry = lookup_type_cache(type_id,
88 : TYPECACHE_TUPDESC |
89 : TYPECACHE_DOMAIN_BASE_INFO);
90 594 : if (typentry->typtype == TYPTYPE_DOMAIN)
91 : {
92 70 : flags |= ER_FLAG_IS_DOMAIN;
93 70 : typentry = lookup_type_cache(typentry->domainBaseType,
94 : TYPECACHE_TUPDESC);
95 : }
96 594 : if (typentry->tupDesc == NULL)
97 0 : ereport(ERROR,
98 : (errcode(ERRCODE_WRONG_OBJECT_TYPE),
99 : errmsg("type %s is not composite",
100 : format_type_be(type_id))));
101 594 : tupdesc = typentry->tupDesc;
102 594 : tupdesc_id = typentry->tupDesc_identifier;
103 : }
104 : else
105 : {
106 : /*
107 : * For RECORD types, get the tupdesc and identifier from typcache.
108 : */
109 60 : tupdesc = lookup_rowtype_tupdesc(type_id, typmod);
110 60 : tupdesc_id = assign_record_type_identifier(type_id, typmod);
111 : }
112 :
113 : /*
114 : * Allocate private context for expanded object. We use a regular-size
115 : * context, not a small one, to improve the odds that we can fit a tupdesc
116 : * into it without needing an extra malloc block. (This code path doesn't
117 : * ever need to copy a tupdesc into the expanded record, but let's be
118 : * consistent with the other ways of making an expanded record.)
119 : */
120 654 : objcxt = AllocSetContextCreate(parentcontext,
121 : "expanded record",
122 : ALLOCSET_DEFAULT_SIZES);
123 :
124 : /*
125 : * Since we already know the number of fields in the tupdesc, we can
126 : * allocate the dvalues/dnulls arrays along with the record header. This
127 : * is useless if we never need those arrays, but it costs almost nothing,
128 : * and it will save a palloc cycle if we do need them.
129 : */
130 : erh = (ExpandedRecordHeader *)
131 654 : MemoryContextAlloc(objcxt, MAXALIGN(sizeof(ExpandedRecordHeader))
132 654 : + tupdesc->natts * (sizeof(Datum) + sizeof(bool)));
133 :
134 : /* Ensure all header fields are initialized to 0/null */
135 654 : memset(erh, 0, sizeof(ExpandedRecordHeader));
136 :
137 654 : EOH_init_header(&erh->hdr, &ER_methods, objcxt);
138 654 : erh->er_magic = ER_MAGIC;
139 :
140 : /* Set up dvalues/dnulls, with no valid contents as yet */
141 654 : chunk = (char *) erh + MAXALIGN(sizeof(ExpandedRecordHeader));
142 654 : erh->dvalues = (Datum *) chunk;
143 654 : erh->dnulls = (bool *) (chunk + tupdesc->natts * sizeof(Datum));
144 654 : erh->nfields = tupdesc->natts;
145 :
146 : /* Fill in composite-type identification info */
147 654 : erh->er_decltypeid = type_id;
148 654 : erh->er_typeid = tupdesc->tdtypeid;
149 654 : erh->er_typmod = tupdesc->tdtypmod;
150 654 : erh->er_tupdesc_id = tupdesc_id;
151 :
152 654 : erh->flags = flags;
153 :
154 : /*
155 : * If what we got from the typcache is a refcounted tupdesc, we need to
156 : * acquire our own refcount on it. We manage the refcount with a memory
157 : * context callback rather than assuming that the CurrentResourceOwner is
158 : * longer-lived than this expanded object.
159 : */
160 654 : if (tupdesc->tdrefcount >= 0)
161 : {
162 : /* Register callback to release the refcount */
163 654 : erh->er_mcb.func = ER_mc_callback;
164 654 : erh->er_mcb.arg = (void *) erh;
165 654 : MemoryContextRegisterResetCallback(erh->hdr.eoh_context,
166 : &erh->er_mcb);
167 :
168 : /* And save the pointer */
169 654 : erh->er_tupdesc = tupdesc;
170 654 : tupdesc->tdrefcount++;
171 :
172 : /* If we called lookup_rowtype_tupdesc, release the pin it took */
173 654 : if (type_id == RECORDOID)
174 60 : ReleaseTupleDesc(tupdesc);
175 : }
176 : else
177 : {
178 : /*
179 : * If it's not refcounted, just assume it will outlive the expanded
180 : * object. (This can happen for shared record types, for instance.)
181 : */
182 0 : erh->er_tupdesc = tupdesc;
183 : }
184 :
185 : /*
186 : * We don't set ER_FLAG_DVALUES_VALID or ER_FLAG_FVALUE_VALID, so the
187 : * record remains logically empty.
188 : */
189 :
190 654 : return erh;
191 : }
192 :
193 : /*
194 : * Build an expanded record of the rowtype defined by the tupdesc
195 : *
196 : * The tupdesc is copied if necessary (i.e., if we can't just bump its
197 : * reference count instead).
198 : *
199 : * The expanded record is initially "empty", having a state logically
200 : * equivalent to a NULL composite value (not ROW(NULL, NULL, ...)).
201 : *
202 : * The expanded object will be a child of parentcontext.
203 : */
204 : ExpandedRecordHeader *
205 20574 : make_expanded_record_from_tupdesc(TupleDesc tupdesc,
206 : MemoryContext parentcontext)
207 : {
208 : ExpandedRecordHeader *erh;
209 : uint64 tupdesc_id;
210 : MemoryContext objcxt;
211 : MemoryContext oldcxt;
212 : char *chunk;
213 :
214 20574 : if (tupdesc->tdtypeid != RECORDOID)
215 : {
216 : /*
217 : * If it's a named composite type (not RECORD), we prefer to reference
218 : * the typcache's copy of the tupdesc, which is guaranteed to be
219 : * refcounted (the given tupdesc might not be). In any case, we need
220 : * to consult the typcache to get the correct tupdesc identifier.
221 : *
222 : * Note that tdtypeid couldn't be a domain type, so we need not
223 : * consider that case here.
224 : */
225 : TypeCacheEntry *typentry;
226 :
227 15154 : typentry = lookup_type_cache(tupdesc->tdtypeid, TYPECACHE_TUPDESC);
228 15154 : if (typentry->tupDesc == NULL)
229 0 : ereport(ERROR,
230 : (errcode(ERRCODE_WRONG_OBJECT_TYPE),
231 : errmsg("type %s is not composite",
232 : format_type_be(tupdesc->tdtypeid))));
233 15154 : tupdesc = typentry->tupDesc;
234 15154 : tupdesc_id = typentry->tupDesc_identifier;
235 : }
236 : else
237 : {
238 : /*
239 : * For RECORD types, get the appropriate unique identifier (possibly
240 : * freshly assigned).
241 : */
242 5420 : tupdesc_id = assign_record_type_identifier(tupdesc->tdtypeid,
243 : tupdesc->tdtypmod);
244 : }
245 :
246 : /*
247 : * Allocate private context for expanded object. We use a regular-size
248 : * context, not a small one, to improve the odds that we can fit a tupdesc
249 : * into it without needing an extra malloc block.
250 : */
251 20574 : objcxt = AllocSetContextCreate(parentcontext,
252 : "expanded record",
253 : ALLOCSET_DEFAULT_SIZES);
254 :
255 : /*
256 : * Since we already know the number of fields in the tupdesc, we can
257 : * allocate the dvalues/dnulls arrays along with the record header. This
258 : * is useless if we never need those arrays, but it costs almost nothing,
259 : * and it will save a palloc cycle if we do need them.
260 : */
261 : erh = (ExpandedRecordHeader *)
262 20574 : MemoryContextAlloc(objcxt, MAXALIGN(sizeof(ExpandedRecordHeader))
263 20574 : + tupdesc->natts * (sizeof(Datum) + sizeof(bool)));
264 :
265 : /* Ensure all header fields are initialized to 0/null */
266 20574 : memset(erh, 0, sizeof(ExpandedRecordHeader));
267 :
268 20574 : EOH_init_header(&erh->hdr, &ER_methods, objcxt);
269 20574 : erh->er_magic = ER_MAGIC;
270 :
271 : /* Set up dvalues/dnulls, with no valid contents as yet */
272 20574 : chunk = (char *) erh + MAXALIGN(sizeof(ExpandedRecordHeader));
273 20574 : erh->dvalues = (Datum *) chunk;
274 20574 : erh->dnulls = (bool *) (chunk + tupdesc->natts * sizeof(Datum));
275 20574 : erh->nfields = tupdesc->natts;
276 :
277 : /* Fill in composite-type identification info */
278 20574 : erh->er_decltypeid = erh->er_typeid = tupdesc->tdtypeid;
279 20574 : erh->er_typmod = tupdesc->tdtypmod;
280 20574 : erh->er_tupdesc_id = tupdesc_id;
281 :
282 : /*
283 : * Copy tupdesc if needed, but we prefer to bump its refcount if possible.
284 : * We manage the refcount with a memory context callback rather than
285 : * assuming that the CurrentResourceOwner is longer-lived than this
286 : * expanded object.
287 : */
288 20574 : if (tupdesc->tdrefcount >= 0)
289 : {
290 : /* Register callback to release the refcount */
291 15154 : erh->er_mcb.func = ER_mc_callback;
292 15154 : erh->er_mcb.arg = (void *) erh;
293 15154 : MemoryContextRegisterResetCallback(erh->hdr.eoh_context,
294 : &erh->er_mcb);
295 :
296 : /* And save the pointer */
297 15154 : erh->er_tupdesc = tupdesc;
298 15154 : tupdesc->tdrefcount++;
299 : }
300 : else
301 : {
302 : /* Just copy it */
303 5420 : oldcxt = MemoryContextSwitchTo(objcxt);
304 5420 : erh->er_tupdesc = CreateTupleDescCopy(tupdesc);
305 5420 : erh->flags |= ER_FLAG_TUPDESC_ALLOCED;
306 5420 : MemoryContextSwitchTo(oldcxt);
307 : }
308 :
309 : /*
310 : * We don't set ER_FLAG_DVALUES_VALID or ER_FLAG_FVALUE_VALID, so the
311 : * record remains logically empty.
312 : */
313 :
314 20574 : return erh;
315 : }
316 :
317 : /*
318 : * Build an expanded record of the same rowtype as the given expanded record
319 : *
320 : * This is faster than either of the above routines because we can bypass
321 : * typcache lookup(s).
322 : *
323 : * The expanded record is initially "empty" --- we do not copy whatever
324 : * tuple might be in the source expanded record.
325 : *
326 : * The expanded object will be a child of parentcontext.
327 : */
328 : ExpandedRecordHeader *
329 15478 : make_expanded_record_from_exprecord(ExpandedRecordHeader *olderh,
330 : MemoryContext parentcontext)
331 : {
332 : ExpandedRecordHeader *erh;
333 15478 : TupleDesc tupdesc = expanded_record_get_tupdesc(olderh);
334 : MemoryContext objcxt;
335 : MemoryContext oldcxt;
336 : char *chunk;
337 :
338 : /*
339 : * Allocate private context for expanded object. We use a regular-size
340 : * context, not a small one, to improve the odds that we can fit a tupdesc
341 : * into it without needing an extra malloc block.
342 : */
343 15478 : objcxt = AllocSetContextCreate(parentcontext,
344 : "expanded record",
345 : ALLOCSET_DEFAULT_SIZES);
346 :
347 : /*
348 : * Since we already know the number of fields in the tupdesc, we can
349 : * allocate the dvalues/dnulls arrays along with the record header. This
350 : * is useless if we never need those arrays, but it costs almost nothing,
351 : * and it will save a palloc cycle if we do need them.
352 : */
353 : erh = (ExpandedRecordHeader *)
354 15478 : MemoryContextAlloc(objcxt, MAXALIGN(sizeof(ExpandedRecordHeader))
355 15478 : + tupdesc->natts * (sizeof(Datum) + sizeof(bool)));
356 :
357 : /* Ensure all header fields are initialized to 0/null */
358 15478 : memset(erh, 0, sizeof(ExpandedRecordHeader));
359 :
360 15478 : EOH_init_header(&erh->hdr, &ER_methods, objcxt);
361 15478 : erh->er_magic = ER_MAGIC;
362 :
363 : /* Set up dvalues/dnulls, with no valid contents as yet */
364 15478 : chunk = (char *) erh + MAXALIGN(sizeof(ExpandedRecordHeader));
365 15478 : erh->dvalues = (Datum *) chunk;
366 15478 : erh->dnulls = (bool *) (chunk + tupdesc->natts * sizeof(Datum));
367 15478 : erh->nfields = tupdesc->natts;
368 :
369 : /* Fill in composite-type identification info */
370 15478 : erh->er_decltypeid = olderh->er_decltypeid;
371 15478 : erh->er_typeid = olderh->er_typeid;
372 15478 : erh->er_typmod = olderh->er_typmod;
373 15478 : erh->er_tupdesc_id = olderh->er_tupdesc_id;
374 :
375 : /* The only flag bit that transfers over is IS_DOMAIN */
376 15478 : erh->flags = olderh->flags & ER_FLAG_IS_DOMAIN;
377 :
378 : /*
379 : * Copy tupdesc if needed, but we prefer to bump its refcount if possible.
380 : * We manage the refcount with a memory context callback rather than
381 : * assuming that the CurrentResourceOwner is longer-lived than this
382 : * expanded object.
383 : */
384 15478 : if (tupdesc->tdrefcount >= 0)
385 : {
386 : /* Register callback to release the refcount */
387 15478 : erh->er_mcb.func = ER_mc_callback;
388 15478 : erh->er_mcb.arg = (void *) erh;
389 15478 : MemoryContextRegisterResetCallback(erh->hdr.eoh_context,
390 : &erh->er_mcb);
391 :
392 : /* And save the pointer */
393 15478 : erh->er_tupdesc = tupdesc;
394 15478 : tupdesc->tdrefcount++;
395 : }
396 0 : else if (olderh->flags & ER_FLAG_TUPDESC_ALLOCED)
397 : {
398 : /* We need to make our own copy of the tupdesc */
399 0 : oldcxt = MemoryContextSwitchTo(objcxt);
400 0 : erh->er_tupdesc = CreateTupleDescCopy(tupdesc);
401 0 : erh->flags |= ER_FLAG_TUPDESC_ALLOCED;
402 0 : MemoryContextSwitchTo(oldcxt);
403 : }
404 : else
405 : {
406 : /*
407 : * Assume the tupdesc will outlive this expanded object, just like
408 : * we're assuming it will outlive the source object.
409 : */
410 0 : erh->er_tupdesc = tupdesc;
411 : }
412 :
413 : /*
414 : * We don't set ER_FLAG_DVALUES_VALID or ER_FLAG_FVALUE_VALID, so the
415 : * record remains logically empty.
416 : */
417 :
418 15478 : return erh;
419 : }
420 :
421 : /*
422 : * Insert given tuple as the value of the expanded record
423 : *
424 : * It is caller's responsibility that the tuple matches the record's
425 : * previously-assigned rowtype. (However domain constraints, if any,
426 : * will be checked here.)
427 : *
428 : * The tuple is physically copied into the expanded record's local storage
429 : * if "copy" is true, otherwise it's caller's responsibility that the tuple
430 : * will live as long as the expanded record does.
431 : *
432 : * Out-of-line field values in the tuple are automatically inlined if
433 : * "expand_external" is true, otherwise not. (The combination copy = false,
434 : * expand_external = true is not sensible and not supported.)
435 : *
436 : * Alternatively, tuple can be NULL, in which case we just set the expanded
437 : * record to be empty.
438 : */
439 : void
440 30524 : expanded_record_set_tuple(ExpandedRecordHeader *erh,
441 : HeapTuple tuple,
442 : bool copy,
443 : bool expand_external)
444 : {
445 : int oldflags;
446 : HeapTuple oldtuple;
447 : char *oldfstartptr;
448 : char *oldfendptr;
449 : int newflags;
450 : HeapTuple newtuple;
451 : MemoryContext oldcxt;
452 :
453 : /* Shouldn't ever be trying to assign new data to a dummy header */
454 : Assert(!(erh->flags & ER_FLAG_IS_DUMMY));
455 :
456 : /*
457 : * Before performing the assignment, see if result will satisfy domain.
458 : */
459 30524 : if (erh->flags & ER_FLAG_IS_DOMAIN)
460 64 : check_domain_for_new_tuple(erh, tuple);
461 :
462 : /*
463 : * If we need to get rid of out-of-line field values, do so, using the
464 : * short-term context to avoid leaking whatever cruft the toast fetch
465 : * might generate.
466 : */
467 30508 : if (expand_external && tuple)
468 : {
469 : /* Assert caller didn't ask for unsupported case */
470 : Assert(copy);
471 4716 : if (HeapTupleHasExternal(tuple))
472 : {
473 16 : oldcxt = MemoryContextSwitchTo(get_short_term_cxt(erh));
474 16 : tuple = toast_flatten_tuple(tuple, erh->er_tupdesc);
475 16 : MemoryContextSwitchTo(oldcxt);
476 : }
477 : else
478 4700 : expand_external = false; /* need not clean up below */
479 : }
480 :
481 : /*
482 : * Initialize new flags, keeping only non-data status bits.
483 : */
484 30508 : oldflags = erh->flags;
485 30508 : newflags = oldflags & ER_FLAGS_NON_DATA;
486 :
487 : /*
488 : * Copy tuple into local storage if needed. We must be sure this succeeds
489 : * before we start to modify the expanded record's state.
490 : */
491 30508 : if (copy && tuple)
492 : {
493 10500 : oldcxt = MemoryContextSwitchTo(erh->hdr.eoh_context);
494 10500 : newtuple = heap_copytuple(tuple);
495 10500 : newflags |= ER_FLAG_FVALUE_ALLOCED;
496 10500 : MemoryContextSwitchTo(oldcxt);
497 :
498 : /* We can now flush anything that detoasting might have leaked. */
499 10500 : if (expand_external)
500 16 : MemoryContextReset(erh->er_short_term_cxt);
501 : }
502 : else
503 20008 : newtuple = tuple;
504 :
505 : /* Make copies of fields we're about to overwrite */
506 30508 : oldtuple = erh->fvalue;
507 30508 : oldfstartptr = erh->fstartptr;
508 30508 : oldfendptr = erh->fendptr;
509 :
510 : /*
511 : * It's now safe to update the expanded record's state.
512 : */
513 30508 : if (newtuple)
514 : {
515 : /* Save flat representation */
516 30484 : erh->fvalue = newtuple;
517 30484 : erh->fstartptr = (char *) newtuple->t_data;
518 30484 : erh->fendptr = ((char *) newtuple->t_data) + newtuple->t_len;
519 30484 : newflags |= ER_FLAG_FVALUE_VALID;
520 :
521 : /* Remember if we have any out-of-line field values */
522 30484 : if (HeapTupleHasExternal(newtuple))
523 206 : newflags |= ER_FLAG_HAVE_EXTERNAL;
524 : }
525 : else
526 : {
527 24 : erh->fvalue = NULL;
528 24 : erh->fstartptr = erh->fendptr = NULL;
529 : }
530 :
531 30508 : erh->flags = newflags;
532 :
533 : /* Reset flat-size info; we don't bother to make it valid now */
534 30508 : erh->flat_size = 0;
535 :
536 : /*
537 : * Now, release any storage belonging to old field values. It's safe to
538 : * do this because ER_FLAG_DVALUES_VALID is no longer set in erh->flags;
539 : * even if we fail partway through, the record is valid, and at worst
540 : * we've failed to reclaim some space.
541 : */
542 30508 : if (oldflags & ER_FLAG_DVALUES_ALLOCED)
543 : {
544 48 : TupleDesc tupdesc = erh->er_tupdesc;
545 : int i;
546 :
547 240 : for (i = 0; i < erh->nfields; i++)
548 : {
549 192 : if (!erh->dnulls[i] &&
550 168 : !(TupleDescAttr(tupdesc, i)->attbyval))
551 : {
552 120 : char *oldValue = (char *) DatumGetPointer(erh->dvalues[i]);
553 :
554 120 : if (oldValue < oldfstartptr || oldValue >= oldfendptr)
555 60 : pfree(oldValue);
556 : }
557 : }
558 : }
559 :
560 : /* Likewise free the old tuple, if it was locally allocated */
561 30508 : if (oldflags & ER_FLAG_FVALUE_ALLOCED)
562 5744 : heap_freetuple(oldtuple);
563 :
564 : /* We won't make a new deconstructed representation until/unless needed */
565 30508 : }
566 :
567 : /*
568 : * make_expanded_record_from_datum: build expanded record from composite Datum
569 : *
570 : * This combines the functions of make_expanded_record_from_typeid and
571 : * expanded_record_set_tuple. However, we do not force a lookup of the
572 : * tupdesc immediately, reasoning that it might never be needed.
573 : *
574 : * The expanded object will be a child of parentcontext.
575 : *
576 : * Note: a composite datum cannot self-identify as being of a domain type,
577 : * so we need not consider domain cases here.
578 : */
579 : Datum
580 0 : make_expanded_record_from_datum(Datum recorddatum, MemoryContext parentcontext)
581 : {
582 : ExpandedRecordHeader *erh;
583 : HeapTupleHeader tuphdr;
584 : HeapTupleData tmptup;
585 : HeapTuple newtuple;
586 : MemoryContext objcxt;
587 : MemoryContext oldcxt;
588 :
589 : /*
590 : * Allocate private context for expanded object. We use a regular-size
591 : * context, not a small one, to improve the odds that we can fit a tupdesc
592 : * into it without needing an extra malloc block.
593 : */
594 0 : objcxt = AllocSetContextCreate(parentcontext,
595 : "expanded record",
596 : ALLOCSET_DEFAULT_SIZES);
597 :
598 : /* Set up expanded record header, initializing fields to 0/null */
599 : erh = (ExpandedRecordHeader *)
600 0 : MemoryContextAllocZero(objcxt, sizeof(ExpandedRecordHeader));
601 :
602 0 : EOH_init_header(&erh->hdr, &ER_methods, objcxt);
603 0 : erh->er_magic = ER_MAGIC;
604 :
605 : /*
606 : * Detoast and copy source record into private context, as a HeapTuple.
607 : * (If we actually have to detoast the source, we'll leak some memory in
608 : * the caller's context, but it doesn't seem worth worrying about.)
609 : */
610 0 : tuphdr = DatumGetHeapTupleHeader(recorddatum);
611 :
612 0 : tmptup.t_len = HeapTupleHeaderGetDatumLength(tuphdr);
613 0 : ItemPointerSetInvalid(&(tmptup.t_self));
614 0 : tmptup.t_tableOid = InvalidOid;
615 0 : tmptup.t_data = tuphdr;
616 :
617 0 : oldcxt = MemoryContextSwitchTo(objcxt);
618 0 : newtuple = heap_copytuple(&tmptup);
619 0 : erh->flags |= ER_FLAG_FVALUE_ALLOCED;
620 0 : MemoryContextSwitchTo(oldcxt);
621 :
622 : /* Fill in composite-type identification info */
623 0 : erh->er_decltypeid = erh->er_typeid = HeapTupleHeaderGetTypeId(tuphdr);
624 0 : erh->er_typmod = HeapTupleHeaderGetTypMod(tuphdr);
625 :
626 : /* remember we have a flat representation */
627 0 : erh->fvalue = newtuple;
628 0 : erh->fstartptr = (char *) newtuple->t_data;
629 0 : erh->fendptr = ((char *) newtuple->t_data) + newtuple->t_len;
630 0 : erh->flags |= ER_FLAG_FVALUE_VALID;
631 :
632 : /* Shouldn't need to set ER_FLAG_HAVE_EXTERNAL */
633 : Assert(!HeapTupleHeaderHasExternal(tuphdr));
634 :
635 : /*
636 : * We won't look up the tupdesc till we have to, nor make a deconstructed
637 : * representation. We don't have enough info to fill flat_size and
638 : * friends, either.
639 : */
640 :
641 : /* return a R/W pointer to the expanded record */
642 0 : return EOHPGetRWDatum(&erh->hdr);
643 : }
644 :
645 : /*
646 : * get_flat_size method for expanded records
647 : *
648 : * Note: call this in a reasonably short-lived memory context, in case of
649 : * memory leaks from activities such as detoasting.
650 : */
651 : static Size
652 2762 : ER_get_flat_size(ExpandedObjectHeader *eohptr)
653 : {
654 2762 : ExpandedRecordHeader *erh = (ExpandedRecordHeader *) eohptr;
655 : TupleDesc tupdesc;
656 : Size len;
657 : Size data_len;
658 : int hoff;
659 : bool hasnull;
660 : int i;
661 :
662 : Assert(erh->er_magic == ER_MAGIC);
663 :
664 : /*
665 : * The flat representation has to be a valid composite datum. Make sure
666 : * that we have a registered, not anonymous, RECORD type.
667 : */
668 2762 : if (erh->er_typeid == RECORDOID &&
669 68 : erh->er_typmod < 0)
670 : {
671 18 : tupdesc = expanded_record_get_tupdesc(erh);
672 18 : assign_record_type_typmod(tupdesc);
673 18 : erh->er_typmod = tupdesc->tdtypmod;
674 : }
675 :
676 : /*
677 : * If we have a valid flattened value without out-of-line fields, we can
678 : * just use it as-is.
679 : */
680 2762 : if (erh->flags & ER_FLAG_FVALUE_VALID &&
681 2466 : !(erh->flags & ER_FLAG_HAVE_EXTERNAL))
682 2418 : return erh->fvalue->t_len;
683 :
684 : /* If we have a cached size value, believe that */
685 344 : if (erh->flat_size)
686 28 : return erh->flat_size;
687 :
688 : /* If we haven't yet deconstructed the tuple, do that */
689 316 : if (!(erh->flags & ER_FLAG_DVALUES_VALID))
690 48 : deconstruct_expanded_record(erh);
691 :
692 : /* Tuple descriptor must be valid by now */
693 316 : tupdesc = erh->er_tupdesc;
694 :
695 : /*
696 : * Composite datums mustn't contain any out-of-line values.
697 : */
698 316 : if (erh->flags & ER_FLAG_HAVE_EXTERNAL)
699 : {
700 240 : for (i = 0; i < erh->nfields; i++)
701 : {
702 192 : Form_pg_attribute attr = TupleDescAttr(tupdesc, i);
703 :
704 192 : if (!erh->dnulls[i] &&
705 168 : !attr->attbyval && attr->attlen == -1 &&
706 120 : VARATT_IS_EXTERNAL(DatumGetPointer(erh->dvalues[i])))
707 : {
708 : /*
709 : * expanded_record_set_field_internal can do the actual work
710 : * of detoasting. It needn't recheck domain constraints.
711 : */
712 60 : expanded_record_set_field_internal(erh, i + 1,
713 60 : erh->dvalues[i], false,
714 : true,
715 : false);
716 : }
717 : }
718 :
719 : /*
720 : * We have now removed all external field values, so we can clear the
721 : * flag about them. This won't cause ER_flatten_into() to mistakenly
722 : * take the fast path, since expanded_record_set_field() will have
723 : * cleared ER_FLAG_FVALUE_VALID.
724 : */
725 48 : erh->flags &= ~ER_FLAG_HAVE_EXTERNAL;
726 : }
727 :
728 : /* Test if we currently have any null values */
729 316 : hasnull = false;
730 968 : for (i = 0; i < erh->nfields; i++)
731 : {
732 700 : if (erh->dnulls[i])
733 : {
734 48 : hasnull = true;
735 48 : break;
736 : }
737 : }
738 :
739 : /* Determine total space needed */
740 316 : len = offsetof(HeapTupleHeaderData, t_bits);
741 :
742 316 : if (hasnull)
743 48 : len += BITMAPLEN(tupdesc->natts);
744 :
745 316 : hoff = len = MAXALIGN(len); /* align user data safely */
746 :
747 316 : data_len = heap_compute_data_size(tupdesc, erh->dvalues, erh->dnulls);
748 :
749 316 : len += data_len;
750 :
751 : /* Cache for next time */
752 316 : erh->flat_size = len;
753 316 : erh->data_len = data_len;
754 316 : erh->hoff = hoff;
755 316 : erh->hasnull = hasnull;
756 :
757 316 : return len;
758 : }
759 :
760 : /*
761 : * flatten_into method for expanded records
762 : */
763 : static void
764 2758 : ER_flatten_into(ExpandedObjectHeader *eohptr,
765 : void *result, Size allocated_size)
766 : {
767 2758 : ExpandedRecordHeader *erh = (ExpandedRecordHeader *) eohptr;
768 2758 : HeapTupleHeader tuphdr = (HeapTupleHeader) result;
769 : TupleDesc tupdesc;
770 :
771 : Assert(erh->er_magic == ER_MAGIC);
772 :
773 : /* Easy if we have a valid flattened value without out-of-line fields */
774 2758 : if (erh->flags & ER_FLAG_FVALUE_VALID &&
775 2418 : !(erh->flags & ER_FLAG_HAVE_EXTERNAL))
776 : {
777 : Assert(allocated_size == erh->fvalue->t_len);
778 2418 : memcpy(tuphdr, erh->fvalue->t_data, allocated_size);
779 : /* The original flattened value might not have datum header fields */
780 2418 : HeapTupleHeaderSetDatumLength(tuphdr, allocated_size);
781 2418 : HeapTupleHeaderSetTypeId(tuphdr, erh->er_typeid);
782 2418 : HeapTupleHeaderSetTypMod(tuphdr, erh->er_typmod);
783 2418 : return;
784 : }
785 :
786 : /* Else allocation should match previous get_flat_size result */
787 : Assert(allocated_size == erh->flat_size);
788 :
789 : /* We'll need the tuple descriptor */
790 340 : tupdesc = expanded_record_get_tupdesc(erh);
791 :
792 : /* We must ensure that any pad space is zero-filled */
793 340 : memset(tuphdr, 0, allocated_size);
794 :
795 : /* Set up header fields of composite Datum */
796 340 : HeapTupleHeaderSetDatumLength(tuphdr, allocated_size);
797 340 : HeapTupleHeaderSetTypeId(tuphdr, erh->er_typeid);
798 340 : HeapTupleHeaderSetTypMod(tuphdr, erh->er_typmod);
799 : /* We also make sure that t_ctid is invalid unless explicitly set */
800 340 : ItemPointerSetInvalid(&(tuphdr->t_ctid));
801 :
802 340 : HeapTupleHeaderSetNatts(tuphdr, tupdesc->natts);
803 340 : tuphdr->t_hoff = erh->hoff;
804 :
805 : /* And fill the data area from dvalues/dnulls */
806 340 : heap_fill_tuple(tupdesc,
807 340 : erh->dvalues,
808 340 : erh->dnulls,
809 340 : (char *) tuphdr + erh->hoff,
810 : erh->data_len,
811 : &tuphdr->t_infomask,
812 340 : (erh->hasnull ? tuphdr->t_bits : NULL));
813 : }
814 :
815 : /*
816 : * Look up the tupdesc for the expanded record's actual type
817 : *
818 : * Note: code internal to this module is allowed to just fetch
819 : * erh->er_tupdesc if ER_FLAG_DVALUES_VALID is set; otherwise it should call
820 : * expanded_record_get_tupdesc. This function is the out-of-line portion
821 : * of expanded_record_get_tupdesc.
822 : */
823 : TupleDesc
824 0 : expanded_record_fetch_tupdesc(ExpandedRecordHeader *erh)
825 : {
826 : TupleDesc tupdesc;
827 :
828 : /* Easy if we already have it (but caller should have checked already) */
829 0 : if (erh->er_tupdesc)
830 0 : return erh->er_tupdesc;
831 :
832 : /* Lookup the composite type's tupdesc using the typcache */
833 0 : tupdesc = lookup_rowtype_tupdesc(erh->er_typeid, erh->er_typmod);
834 :
835 : /*
836 : * If it's a refcounted tupdesc rather than a statically allocated one, we
837 : * want to manage the refcount with a memory context callback rather than
838 : * assuming that the CurrentResourceOwner is longer-lived than this
839 : * expanded object.
840 : */
841 0 : if (tupdesc->tdrefcount >= 0)
842 : {
843 : /* Register callback if we didn't already */
844 0 : if (erh->er_mcb.arg == NULL)
845 : {
846 0 : erh->er_mcb.func = ER_mc_callback;
847 0 : erh->er_mcb.arg = (void *) erh;
848 0 : MemoryContextRegisterResetCallback(erh->hdr.eoh_context,
849 : &erh->er_mcb);
850 : }
851 :
852 : /* Remember our own pointer */
853 0 : erh->er_tupdesc = tupdesc;
854 0 : tupdesc->tdrefcount++;
855 :
856 : /* Release the pin lookup_rowtype_tupdesc acquired */
857 0 : ReleaseTupleDesc(tupdesc);
858 : }
859 : else
860 : {
861 : /* Just remember the pointer */
862 0 : erh->er_tupdesc = tupdesc;
863 : }
864 :
865 : /* In either case, fetch the process-global ID for this tupdesc */
866 0 : erh->er_tupdesc_id = assign_record_type_identifier(tupdesc->tdtypeid,
867 : tupdesc->tdtypmod);
868 :
869 0 : return tupdesc;
870 : }
871 :
872 : /*
873 : * Get a HeapTuple representing the current value of the expanded record
874 : *
875 : * If valid, the originally stored tuple is returned, so caller must not
876 : * scribble on it. Otherwise, we return a HeapTuple created in the current
877 : * memory context. In either case, no attempt has been made to inline
878 : * out-of-line toasted values, so the tuple isn't usable as a composite
879 : * datum.
880 : *
881 : * Returns NULL if expanded record is empty.
882 : */
883 : HeapTuple
884 12434 : expanded_record_get_tuple(ExpandedRecordHeader *erh)
885 : {
886 : /* Easy case if we still have original tuple */
887 12434 : if (erh->flags & ER_FLAG_FVALUE_VALID)
888 10630 : return erh->fvalue;
889 :
890 : /* Else just build a tuple from datums */
891 1804 : if (erh->flags & ER_FLAG_DVALUES_VALID)
892 1804 : return heap_form_tuple(erh->er_tupdesc, erh->dvalues, erh->dnulls);
893 :
894 : /* Expanded record is empty */
895 0 : return NULL;
896 : }
897 :
898 : /*
899 : * Memory context reset callback for cleaning up external resources
900 : */
901 : static void
902 31286 : ER_mc_callback(void *arg)
903 : {
904 31286 : ExpandedRecordHeader *erh = (ExpandedRecordHeader *) arg;
905 31286 : TupleDesc tupdesc = erh->er_tupdesc;
906 :
907 : /* Release our privately-managed tupdesc refcount, if any */
908 31286 : if (tupdesc)
909 : {
910 31286 : erh->er_tupdesc = NULL; /* just for luck */
911 31286 : if (tupdesc->tdrefcount > 0)
912 : {
913 31286 : if (--tupdesc->tdrefcount == 0)
914 0 : FreeTupleDesc(tupdesc);
915 : }
916 : }
917 31286 : }
918 :
919 : /*
920 : * DatumGetExpandedRecord: get a writable expanded record from an input argument
921 : *
922 : * Caution: if the input is a read/write pointer, this returns the input
923 : * argument; so callers must be sure that their changes are "safe", that is
924 : * they cannot leave the record in a corrupt state.
925 : */
926 : ExpandedRecordHeader *
927 0 : DatumGetExpandedRecord(Datum d)
928 : {
929 : /* If it's a writable expanded record already, just return it */
930 0 : if (VARATT_IS_EXTERNAL_EXPANDED_RW(DatumGetPointer(d)))
931 : {
932 0 : ExpandedRecordHeader *erh = (ExpandedRecordHeader *) DatumGetEOHP(d);
933 :
934 : Assert(erh->er_magic == ER_MAGIC);
935 0 : return erh;
936 : }
937 :
938 : /* Else expand the hard way */
939 0 : d = make_expanded_record_from_datum(d, CurrentMemoryContext);
940 0 : return (ExpandedRecordHeader *) DatumGetEOHP(d);
941 : }
942 :
943 : /*
944 : * Create the Datum/isnull representation of an expanded record object
945 : * if we didn't do so already. After calling this, it's OK to read the
946 : * dvalues/dnulls arrays directly, rather than going through get_field.
947 : *
948 : * Note that if the object is currently empty ("null"), this will change
949 : * it to represent a row of nulls.
950 : */
951 : void
952 23826 : deconstruct_expanded_record(ExpandedRecordHeader *erh)
953 : {
954 : TupleDesc tupdesc;
955 : Datum *dvalues;
956 : bool *dnulls;
957 : int nfields;
958 :
959 23826 : if (erh->flags & ER_FLAG_DVALUES_VALID)
960 30 : return; /* already valid, nothing to do */
961 :
962 : /* We'll need the tuple descriptor */
963 23796 : tupdesc = expanded_record_get_tupdesc(erh);
964 :
965 : /*
966 : * Allocate arrays in private context, if we don't have them already. We
967 : * don't expect to see a change in nfields here, so while we cope if it
968 : * happens, we don't bother avoiding a leak of the old arrays (which might
969 : * not be separately palloc'd, anyway).
970 : */
971 23796 : nfields = tupdesc->natts;
972 23796 : if (erh->dvalues == NULL || erh->nfields != nfields)
973 0 : {
974 : char *chunk;
975 :
976 : /*
977 : * To save a palloc cycle, we allocate both the Datum and isnull
978 : * arrays in one palloc chunk.
979 : */
980 0 : chunk = MemoryContextAlloc(erh->hdr.eoh_context,
981 : nfields * (sizeof(Datum) + sizeof(bool)));
982 0 : dvalues = (Datum *) chunk;
983 0 : dnulls = (bool *) (chunk + nfields * sizeof(Datum));
984 0 : erh->dvalues = dvalues;
985 0 : erh->dnulls = dnulls;
986 0 : erh->nfields = nfields;
987 : }
988 : else
989 : {
990 23796 : dvalues = erh->dvalues;
991 23796 : dnulls = erh->dnulls;
992 : }
993 :
994 23796 : if (erh->flags & ER_FLAG_FVALUE_VALID)
995 : {
996 : /* Deconstruct tuple */
997 22092 : heap_deform_tuple(erh->fvalue, tupdesc, dvalues, dnulls);
998 : }
999 : else
1000 : {
1001 : /* If record was empty, instantiate it as a row of nulls */
1002 1704 : memset(dvalues, 0, nfields * sizeof(Datum));
1003 1704 : memset(dnulls, true, nfields * sizeof(bool));
1004 : }
1005 :
1006 : /* Mark the dvalues as valid */
1007 23796 : erh->flags |= ER_FLAG_DVALUES_VALID;
1008 : }
1009 :
1010 : /*
1011 : * Look up a record field by name
1012 : *
1013 : * If there is a field named "fieldname", fill in the contents of finfo
1014 : * and return "true". Else return "false" without changing *finfo.
1015 : */
1016 : bool
1017 6194 : expanded_record_lookup_field(ExpandedRecordHeader *erh, const char *fieldname,
1018 : ExpandedRecordFieldInfo *finfo)
1019 : {
1020 : TupleDesc tupdesc;
1021 : int fno;
1022 : Form_pg_attribute attr;
1023 : const FormData_pg_attribute *sysattr;
1024 :
1025 6194 : tupdesc = expanded_record_get_tupdesc(erh);
1026 :
1027 : /* First, check user-defined attributes */
1028 22200 : for (fno = 0; fno < tupdesc->natts; fno++)
1029 : {
1030 22172 : attr = TupleDescAttr(tupdesc, fno);
1031 22172 : if (namestrcmp(&attr->attname, fieldname) == 0 &&
1032 6166 : !attr->attisdropped)
1033 : {
1034 6166 : finfo->fnumber = attr->attnum;
1035 6166 : finfo->ftypeid = attr->atttypid;
1036 6166 : finfo->ftypmod = attr->atttypmod;
1037 6166 : finfo->fcollation = attr->attcollation;
1038 6166 : return true;
1039 : }
1040 : }
1041 :
1042 : /* How about system attributes? */
1043 28 : sysattr = SystemAttributeByName(fieldname);
1044 28 : if (sysattr != NULL)
1045 : {
1046 4 : finfo->fnumber = sysattr->attnum;
1047 4 : finfo->ftypeid = sysattr->atttypid;
1048 4 : finfo->ftypmod = sysattr->atttypmod;
1049 4 : finfo->fcollation = sysattr->attcollation;
1050 4 : return true;
1051 : }
1052 :
1053 24 : return false;
1054 : }
1055 :
1056 : /*
1057 : * Fetch value of record field
1058 : *
1059 : * expanded_record_get_field is the frontend for this; it handles the
1060 : * easy inline-able cases.
1061 : */
1062 : Datum
1063 21832 : expanded_record_fetch_field(ExpandedRecordHeader *erh, int fnumber,
1064 : bool *isnull)
1065 : {
1066 21832 : if (fnumber > 0)
1067 : {
1068 : /* Empty record has null fields */
1069 21824 : if (ExpandedRecordIsEmpty(erh))
1070 : {
1071 54 : *isnull = true;
1072 54 : return (Datum) 0;
1073 : }
1074 : /* Make sure we have deconstructed form */
1075 21770 : deconstruct_expanded_record(erh);
1076 : /* Out-of-range field number reads as null */
1077 21770 : if (unlikely(fnumber > erh->nfields))
1078 : {
1079 0 : *isnull = true;
1080 0 : return (Datum) 0;
1081 : }
1082 21770 : *isnull = erh->dnulls[fnumber - 1];
1083 21770 : return erh->dvalues[fnumber - 1];
1084 : }
1085 : else
1086 : {
1087 : /* System columns read as null if we haven't got flat tuple */
1088 8 : if (erh->fvalue == NULL)
1089 : {
1090 0 : *isnull = true;
1091 0 : return (Datum) 0;
1092 : }
1093 : /* heap_getsysattr doesn't actually use tupdesc, so just pass null */
1094 8 : return heap_getsysattr(erh->fvalue, fnumber, NULL, isnull);
1095 : }
1096 : }
1097 :
1098 : /*
1099 : * Set value of record field
1100 : *
1101 : * If the expanded record is of domain type, the assignment will be rejected
1102 : * (without changing the record's state) if the domain's constraints would
1103 : * be violated.
1104 : *
1105 : * If expand_external is true and newValue is an out-of-line value, we'll
1106 : * forcibly detoast it so that the record does not depend on external storage.
1107 : *
1108 : * Internal callers can pass check_constraints = false to skip application
1109 : * of domain constraints. External callers should never do that.
1110 : */
1111 : void
1112 2324 : expanded_record_set_field_internal(ExpandedRecordHeader *erh, int fnumber,
1113 : Datum newValue, bool isnull,
1114 : bool expand_external,
1115 : bool check_constraints)
1116 : {
1117 : TupleDesc tupdesc;
1118 : Form_pg_attribute attr;
1119 : Datum *dvalues;
1120 : bool *dnulls;
1121 : char *oldValue;
1122 :
1123 : /*
1124 : * Shouldn't ever be trying to assign new data to a dummy header, except
1125 : * in the case of an internal call for field inlining.
1126 : */
1127 : Assert(!(erh->flags & ER_FLAG_IS_DUMMY) || !check_constraints);
1128 :
1129 : /* Before performing the assignment, see if result will satisfy domain */
1130 2324 : if ((erh->flags & ER_FLAG_IS_DOMAIN) && check_constraints)
1131 24 : check_domain_for_new_field(erh, fnumber, newValue, isnull);
1132 :
1133 : /* If we haven't yet deconstructed the tuple, do that */
1134 2318 : if (!(erh->flags & ER_FLAG_DVALUES_VALID))
1135 380 : deconstruct_expanded_record(erh);
1136 :
1137 : /* Tuple descriptor must be valid by now */
1138 2318 : tupdesc = erh->er_tupdesc;
1139 : Assert(erh->nfields == tupdesc->natts);
1140 :
1141 : /* Caller error if fnumber is system column or nonexistent column */
1142 2318 : if (unlikely(fnumber <= 0 || fnumber > erh->nfields))
1143 0 : elog(ERROR, "cannot assign to field %d of expanded record", fnumber);
1144 :
1145 : /*
1146 : * Copy new field value into record's context, and deal with detoasting,
1147 : * if needed.
1148 : */
1149 2318 : attr = TupleDescAttr(tupdesc, fnumber - 1);
1150 2318 : if (!isnull && !attr->attbyval)
1151 : {
1152 : MemoryContext oldcxt;
1153 :
1154 : /* If requested, detoast any external value */
1155 1490 : if (expand_external)
1156 : {
1157 102 : if (attr->attlen == -1 &&
1158 102 : VARATT_IS_EXTERNAL(DatumGetPointer(newValue)))
1159 : {
1160 : /* Detoasting should be done in short-lived context. */
1161 62 : oldcxt = MemoryContextSwitchTo(get_short_term_cxt(erh));
1162 62 : newValue = PointerGetDatum(detoast_external_attr((struct varlena *) DatumGetPointer(newValue)));
1163 62 : MemoryContextSwitchTo(oldcxt);
1164 : }
1165 : else
1166 40 : expand_external = false; /* need not clean up below */
1167 : }
1168 :
1169 : /* Copy value into record's context */
1170 1490 : oldcxt = MemoryContextSwitchTo(erh->hdr.eoh_context);
1171 1490 : newValue = datumCopy(newValue, false, attr->attlen);
1172 1490 : MemoryContextSwitchTo(oldcxt);
1173 :
1174 : /* We can now flush anything that detoasting might have leaked */
1175 1490 : if (expand_external)
1176 62 : MemoryContextReset(erh->er_short_term_cxt);
1177 :
1178 : /* Remember that we have field(s) that may need to be pfree'd */
1179 1490 : erh->flags |= ER_FLAG_DVALUES_ALLOCED;
1180 :
1181 : /*
1182 : * While we're here, note whether it's an external toasted value,
1183 : * because that could mean we need to inline it later. (Think not to
1184 : * merge this into the previous expand_external logic: datumCopy could
1185 : * by itself have made the value non-external.)
1186 : */
1187 1490 : if (attr->attlen == -1 &&
1188 1490 : VARATT_IS_EXTERNAL(DatumGetPointer(newValue)))
1189 0 : erh->flags |= ER_FLAG_HAVE_EXTERNAL;
1190 : }
1191 :
1192 : /*
1193 : * We're ready to make irreversible changes.
1194 : */
1195 2318 : dvalues = erh->dvalues;
1196 2318 : dnulls = erh->dnulls;
1197 :
1198 : /* Flattened value will no longer represent record accurately */
1199 2318 : erh->flags &= ~ER_FLAG_FVALUE_VALID;
1200 : /* And we don't know the flattened size either */
1201 2318 : erh->flat_size = 0;
1202 :
1203 : /* Grab old field value for pfree'ing, if needed. */
1204 2318 : if (!attr->attbyval && !dnulls[fnumber - 1])
1205 1394 : oldValue = (char *) DatumGetPointer(dvalues[fnumber - 1]);
1206 : else
1207 924 : oldValue = NULL;
1208 :
1209 : /* And finally we can insert the new field. */
1210 2318 : dvalues[fnumber - 1] = newValue;
1211 2318 : dnulls[fnumber - 1] = isnull;
1212 :
1213 : /*
1214 : * Free old field if needed; this keeps repeated field replacements from
1215 : * bloating the record's storage. If the pfree somehow fails, it won't
1216 : * corrupt the record.
1217 : *
1218 : * If we're updating a dummy header, we can't risk pfree'ing the old
1219 : * value, because most likely the expanded record's main header still has
1220 : * a pointer to it. This won't result in any sustained memory leak, since
1221 : * whatever we just allocated here is in the short-lived domain check
1222 : * context.
1223 : */
1224 2318 : if (oldValue && !(erh->flags & ER_FLAG_IS_DUMMY))
1225 : {
1226 : /* Don't try to pfree a part of the original flat record */
1227 1394 : if (oldValue < erh->fstartptr || oldValue >= erh->fendptr)
1228 28 : pfree(oldValue);
1229 : }
1230 2318 : }
1231 :
1232 : /*
1233 : * Set all record field(s)
1234 : *
1235 : * Caller must ensure that the provided datums are of the right types
1236 : * to match the record's previously assigned rowtype.
1237 : *
1238 : * If expand_external is true, we'll forcibly detoast out-of-line field values
1239 : * so that the record does not depend on external storage.
1240 : *
1241 : * Unlike repeated application of expanded_record_set_field(), this does not
1242 : * guarantee to leave the expanded record in a non-corrupt state in event
1243 : * of an error. Typically it would only be used for initializing a new
1244 : * expanded record. Also, because we expect this to be applied at most once
1245 : * in the lifespan of an expanded record, we do not worry about any cruft
1246 : * that detoasting might leak.
1247 : */
1248 : void
1249 102 : expanded_record_set_fields(ExpandedRecordHeader *erh,
1250 : const Datum *newValues, const bool *isnulls,
1251 : bool expand_external)
1252 : {
1253 : TupleDesc tupdesc;
1254 : Datum *dvalues;
1255 : bool *dnulls;
1256 : int fnumber;
1257 : MemoryContext oldcxt;
1258 :
1259 : /* Shouldn't ever be trying to assign new data to a dummy header */
1260 : Assert(!(erh->flags & ER_FLAG_IS_DUMMY));
1261 :
1262 : /* If we haven't yet deconstructed the tuple, do that */
1263 102 : if (!(erh->flags & ER_FLAG_DVALUES_VALID))
1264 102 : deconstruct_expanded_record(erh);
1265 :
1266 : /* Tuple descriptor must be valid by now */
1267 102 : tupdesc = erh->er_tupdesc;
1268 : Assert(erh->nfields == tupdesc->natts);
1269 :
1270 : /* Flattened value will no longer represent record accurately */
1271 102 : erh->flags &= ~ER_FLAG_FVALUE_VALID;
1272 : /* And we don't know the flattened size either */
1273 102 : erh->flat_size = 0;
1274 :
1275 102 : oldcxt = MemoryContextSwitchTo(erh->hdr.eoh_context);
1276 :
1277 102 : dvalues = erh->dvalues;
1278 102 : dnulls = erh->dnulls;
1279 :
1280 314 : for (fnumber = 0; fnumber < erh->nfields; fnumber++)
1281 : {
1282 212 : Form_pg_attribute attr = TupleDescAttr(tupdesc, fnumber);
1283 : Datum newValue;
1284 : bool isnull;
1285 :
1286 : /* Ignore dropped columns */
1287 212 : if (attr->attisdropped)
1288 8 : continue;
1289 :
1290 204 : newValue = newValues[fnumber];
1291 204 : isnull = isnulls[fnumber];
1292 :
1293 204 : if (!attr->attbyval)
1294 : {
1295 : /*
1296 : * Copy new field value into record's context, and deal with
1297 : * detoasting, if needed.
1298 : */
1299 26 : if (!isnull)
1300 : {
1301 : /* Is it an external toasted value? */
1302 26 : if (attr->attlen == -1 &&
1303 26 : VARATT_IS_EXTERNAL(DatumGetPointer(newValue)))
1304 : {
1305 2 : if (expand_external)
1306 : {
1307 : /* Detoast as requested while copying the value */
1308 2 : newValue = PointerGetDatum(detoast_external_attr((struct varlena *) DatumGetPointer(newValue)));
1309 : }
1310 : else
1311 : {
1312 : /* Just copy the value */
1313 0 : newValue = datumCopy(newValue, false, -1);
1314 : /* If it's still external, remember that */
1315 0 : if (VARATT_IS_EXTERNAL(DatumGetPointer(newValue)))
1316 0 : erh->flags |= ER_FLAG_HAVE_EXTERNAL;
1317 : }
1318 : }
1319 : else
1320 : {
1321 : /* Not an external value, just copy it */
1322 24 : newValue = datumCopy(newValue, false, attr->attlen);
1323 : }
1324 :
1325 : /* Remember that we have field(s) that need to be pfree'd */
1326 26 : erh->flags |= ER_FLAG_DVALUES_ALLOCED;
1327 : }
1328 :
1329 : /*
1330 : * Free old field value, if any (not likely, since really we ought
1331 : * to be inserting into an empty record).
1332 : */
1333 26 : if (unlikely(!dnulls[fnumber]))
1334 : {
1335 : char *oldValue;
1336 :
1337 0 : oldValue = (char *) DatumGetPointer(dvalues[fnumber]);
1338 : /* Don't try to pfree a part of the original flat record */
1339 0 : if (oldValue < erh->fstartptr || oldValue >= erh->fendptr)
1340 0 : pfree(oldValue);
1341 : }
1342 : }
1343 :
1344 : /* And finally we can insert the new field. */
1345 204 : dvalues[fnumber] = newValue;
1346 204 : dnulls[fnumber] = isnull;
1347 : }
1348 :
1349 : /*
1350 : * Because we don't guarantee atomicity of set_fields(), we can just leave
1351 : * checking of domain constraints to occur as the final step; if it throws
1352 : * an error, too bad.
1353 : */
1354 102 : if (erh->flags & ER_FLAG_IS_DOMAIN)
1355 : {
1356 : /* We run domain_check in a short-lived context to limit cruft */
1357 18 : MemoryContextSwitchTo(get_short_term_cxt(erh));
1358 :
1359 18 : domain_check(ExpandedRecordGetRODatum(erh), false,
1360 : erh->er_decltypeid,
1361 : &erh->er_domaininfo,
1362 : erh->hdr.eoh_context);
1363 : }
1364 :
1365 94 : MemoryContextSwitchTo(oldcxt);
1366 94 : }
1367 :
1368 : /*
1369 : * Construct (or reset) working memory context for short-term operations.
1370 : *
1371 : * This context is used for domain check evaluation and for detoasting.
1372 : *
1373 : * If we don't have a short-lived memory context, make one; if we have one,
1374 : * reset it to get rid of any leftover cruft. (It is a tad annoying to need a
1375 : * whole context for this, since it will often go unused --- but it's hard to
1376 : * avoid memory leaks otherwise. We can make the context small, at least.)
1377 : */
1378 : static MemoryContext
1379 184 : get_short_term_cxt(ExpandedRecordHeader *erh)
1380 : {
1381 184 : if (erh->er_short_term_cxt == NULL)
1382 136 : erh->er_short_term_cxt =
1383 136 : AllocSetContextCreate(erh->hdr.eoh_context,
1384 : "expanded record short-term context",
1385 : ALLOCSET_SMALL_SIZES);
1386 : else
1387 48 : MemoryContextReset(erh->er_short_term_cxt);
1388 184 : return erh->er_short_term_cxt;
1389 : }
1390 :
1391 : /*
1392 : * Construct "dummy header" for checking domain constraints.
1393 : *
1394 : * Since we don't want to modify the state of the expanded record until
1395 : * we've validated the constraints, our approach is to set up a dummy
1396 : * record header containing the new field value(s) and then pass that to
1397 : * domain_check. We retain the dummy header as part of the expanded
1398 : * record's state to save palloc cycles, but reinitialize (most of)
1399 : * its contents on each use.
1400 : */
1401 : static void
1402 56 : build_dummy_expanded_header(ExpandedRecordHeader *main_erh)
1403 : {
1404 : ExpandedRecordHeader *erh;
1405 56 : TupleDesc tupdesc = expanded_record_get_tupdesc(main_erh);
1406 :
1407 : /* Ensure we have a short-lived context */
1408 56 : (void) get_short_term_cxt(main_erh);
1409 :
1410 : /*
1411 : * Allocate dummy header on first time through, or in the unlikely event
1412 : * that the number of fields changes (in which case we just leak the old
1413 : * one). Include space for its field values in the request.
1414 : */
1415 56 : erh = main_erh->er_dummy_header;
1416 56 : if (erh == NULL || erh->nfields != tupdesc->natts)
1417 : {
1418 : char *chunk;
1419 :
1420 : erh = (ExpandedRecordHeader *)
1421 36 : MemoryContextAlloc(main_erh->hdr.eoh_context,
1422 : MAXALIGN(sizeof(ExpandedRecordHeader))
1423 36 : + tupdesc->natts * (sizeof(Datum) + sizeof(bool)));
1424 :
1425 : /* Ensure all header fields are initialized to 0/null */
1426 36 : memset(erh, 0, sizeof(ExpandedRecordHeader));
1427 :
1428 : /*
1429 : * We set up the dummy header with an indication that its memory
1430 : * context is the short-lived context. This is so that, if any
1431 : * detoasting of out-of-line values happens due to an attempt to
1432 : * extract a composite datum from the dummy header, the detoasted
1433 : * stuff will end up in the short-lived context and not cause a leak.
1434 : * This is cheating a bit on the expanded-object protocol; but since
1435 : * we never pass a R/W pointer to the dummy object to any other code,
1436 : * nothing else is authorized to delete or transfer ownership of the
1437 : * object's context, so it should be safe enough.
1438 : */
1439 36 : EOH_init_header(&erh->hdr, &ER_methods, main_erh->er_short_term_cxt);
1440 36 : erh->er_magic = ER_MAGIC;
1441 :
1442 : /* Set up dvalues/dnulls, with no valid contents as yet */
1443 36 : chunk = (char *) erh + MAXALIGN(sizeof(ExpandedRecordHeader));
1444 36 : erh->dvalues = (Datum *) chunk;
1445 36 : erh->dnulls = (bool *) (chunk + tupdesc->natts * sizeof(Datum));
1446 36 : erh->nfields = tupdesc->natts;
1447 :
1448 : /*
1449 : * The fields we just set are assumed to remain constant through
1450 : * multiple uses of the dummy header to check domain constraints. All
1451 : * other dummy header fields should be explicitly reset below, to
1452 : * ensure there's not accidental effects of one check on the next one.
1453 : */
1454 :
1455 36 : main_erh->er_dummy_header = erh;
1456 : }
1457 :
1458 : /*
1459 : * If anything inquires about the dummy header's declared type, it should
1460 : * report the composite base type, not the domain type (since the VALUE in
1461 : * a domain check constraint is of the base type not the domain). Hence
1462 : * we do not transfer over the IS_DOMAIN flag, nor indeed any of the main
1463 : * header's flags, since the dummy header is empty of data at this point.
1464 : * But don't forget to mark header as dummy.
1465 : */
1466 56 : erh->flags = ER_FLAG_IS_DUMMY;
1467 :
1468 : /* Copy composite-type identification info */
1469 56 : erh->er_decltypeid = erh->er_typeid = main_erh->er_typeid;
1470 56 : erh->er_typmod = main_erh->er_typmod;
1471 :
1472 : /* Dummy header does not need its own tupdesc refcount */
1473 56 : erh->er_tupdesc = tupdesc;
1474 56 : erh->er_tupdesc_id = main_erh->er_tupdesc_id;
1475 :
1476 : /*
1477 : * It's tempting to copy over whatever we know about the flat size, but
1478 : * there's no point since we're surely about to modify the dummy record's
1479 : * field(s). Instead just clear anything left over from a previous usage
1480 : * cycle.
1481 : */
1482 56 : erh->flat_size = 0;
1483 :
1484 : /* Copy over fvalue if we have it, so that system columns are available */
1485 56 : erh->fvalue = main_erh->fvalue;
1486 56 : erh->fstartptr = main_erh->fstartptr;
1487 56 : erh->fendptr = main_erh->fendptr;
1488 56 : }
1489 :
1490 : /*
1491 : * Precheck domain constraints for a set_field operation
1492 : */
1493 : static pg_noinline void
1494 24 : check_domain_for_new_field(ExpandedRecordHeader *erh, int fnumber,
1495 : Datum newValue, bool isnull)
1496 : {
1497 : ExpandedRecordHeader *dummy_erh;
1498 : MemoryContext oldcxt;
1499 :
1500 : /* Construct dummy header to contain proposed new field set */
1501 24 : build_dummy_expanded_header(erh);
1502 24 : dummy_erh = erh->er_dummy_header;
1503 :
1504 : /*
1505 : * If record isn't empty, just deconstruct it (if needed) and copy over
1506 : * the existing field values. If it is empty, just fill fields with nulls
1507 : * manually --- don't call deconstruct_expanded_record prematurely.
1508 : */
1509 24 : if (!ExpandedRecordIsEmpty(erh))
1510 : {
1511 16 : deconstruct_expanded_record(erh);
1512 16 : memcpy(dummy_erh->dvalues, erh->dvalues,
1513 16 : dummy_erh->nfields * sizeof(Datum));
1514 16 : memcpy(dummy_erh->dnulls, erh->dnulls,
1515 16 : dummy_erh->nfields * sizeof(bool));
1516 : /* There might be some external values in there... */
1517 16 : dummy_erh->flags |= erh->flags & ER_FLAG_HAVE_EXTERNAL;
1518 : }
1519 : else
1520 : {
1521 8 : memset(dummy_erh->dvalues, 0, dummy_erh->nfields * sizeof(Datum));
1522 8 : memset(dummy_erh->dnulls, true, dummy_erh->nfields * sizeof(bool));
1523 : }
1524 :
1525 : /* Either way, we now have valid dvalues */
1526 24 : dummy_erh->flags |= ER_FLAG_DVALUES_VALID;
1527 :
1528 : /* Caller error if fnumber is system column or nonexistent column */
1529 24 : if (unlikely(fnumber <= 0 || fnumber > dummy_erh->nfields))
1530 0 : elog(ERROR, "cannot assign to field %d of expanded record", fnumber);
1531 :
1532 : /* Insert proposed new value into dummy field array */
1533 24 : dummy_erh->dvalues[fnumber - 1] = newValue;
1534 24 : dummy_erh->dnulls[fnumber - 1] = isnull;
1535 :
1536 : /*
1537 : * The proposed new value might be external, in which case we'd better set
1538 : * the flag for that in dummy_erh. (This matters in case something in the
1539 : * domain check expressions tries to extract a flat value from the dummy
1540 : * header.)
1541 : */
1542 24 : if (!isnull)
1543 : {
1544 22 : Form_pg_attribute attr = TupleDescAttr(erh->er_tupdesc, fnumber - 1);
1545 :
1546 22 : if (!attr->attbyval && attr->attlen == -1 &&
1547 12 : VARATT_IS_EXTERNAL(DatumGetPointer(newValue)))
1548 0 : dummy_erh->flags |= ER_FLAG_HAVE_EXTERNAL;
1549 : }
1550 :
1551 : /*
1552 : * We call domain_check in the short-lived context, so that any cruft
1553 : * leaked by expression evaluation can be reclaimed.
1554 : */
1555 24 : oldcxt = MemoryContextSwitchTo(erh->er_short_term_cxt);
1556 :
1557 : /*
1558 : * And now we can apply the check. Note we use main header's domain cache
1559 : * space, so that caching carries across repeated uses.
1560 : */
1561 24 : domain_check(ExpandedRecordGetRODatum(dummy_erh), false,
1562 : erh->er_decltypeid,
1563 : &erh->er_domaininfo,
1564 : erh->hdr.eoh_context);
1565 :
1566 18 : MemoryContextSwitchTo(oldcxt);
1567 :
1568 : /* We might as well clean up cruft immediately. */
1569 18 : MemoryContextReset(erh->er_short_term_cxt);
1570 18 : }
1571 :
1572 : /*
1573 : * Precheck domain constraints for a set_tuple operation
1574 : */
1575 : static pg_noinline void
1576 64 : check_domain_for_new_tuple(ExpandedRecordHeader *erh, HeapTuple tuple)
1577 : {
1578 : ExpandedRecordHeader *dummy_erh;
1579 : MemoryContext oldcxt;
1580 :
1581 : /* If we're being told to set record to empty, just see if NULL is OK */
1582 64 : if (tuple == NULL)
1583 : {
1584 : /* We run domain_check in a short-lived context to limit cruft */
1585 32 : oldcxt = MemoryContextSwitchTo(get_short_term_cxt(erh));
1586 :
1587 32 : domain_check((Datum) 0, true,
1588 : erh->er_decltypeid,
1589 : &erh->er_domaininfo,
1590 : erh->hdr.eoh_context);
1591 :
1592 24 : MemoryContextSwitchTo(oldcxt);
1593 :
1594 : /* We might as well clean up cruft immediately. */
1595 24 : MemoryContextReset(erh->er_short_term_cxt);
1596 :
1597 24 : return;
1598 : }
1599 :
1600 : /* Construct dummy header to contain replacement tuple */
1601 32 : build_dummy_expanded_header(erh);
1602 32 : dummy_erh = erh->er_dummy_header;
1603 :
1604 : /* Insert tuple, but don't bother to deconstruct its fields for now */
1605 32 : dummy_erh->fvalue = tuple;
1606 32 : dummy_erh->fstartptr = (char *) tuple->t_data;
1607 32 : dummy_erh->fendptr = ((char *) tuple->t_data) + tuple->t_len;
1608 32 : dummy_erh->flags |= ER_FLAG_FVALUE_VALID;
1609 :
1610 : /* Remember if we have any out-of-line field values */
1611 32 : if (HeapTupleHasExternal(tuple))
1612 4 : dummy_erh->flags |= ER_FLAG_HAVE_EXTERNAL;
1613 :
1614 : /*
1615 : * We call domain_check in the short-lived context, so that any cruft
1616 : * leaked by expression evaluation can be reclaimed.
1617 : */
1618 32 : oldcxt = MemoryContextSwitchTo(erh->er_short_term_cxt);
1619 :
1620 : /*
1621 : * And now we can apply the check. Note we use main header's domain cache
1622 : * space, so that caching carries across repeated uses.
1623 : */
1624 32 : domain_check(ExpandedRecordGetRODatum(dummy_erh), false,
1625 : erh->er_decltypeid,
1626 : &erh->er_domaininfo,
1627 : erh->hdr.eoh_context);
1628 :
1629 24 : MemoryContextSwitchTo(oldcxt);
1630 :
1631 : /* We might as well clean up cruft immediately. */
1632 24 : MemoryContextReset(erh->er_short_term_cxt);
1633 : }
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