1 | /*------------------------------------------------------------------------- |
2 | * |
3 | * execTuples.c |
4 | * Routines dealing with TupleTableSlots. These are used for resource |
5 | * management associated with tuples (eg, releasing buffer pins for |
6 | * tuples in disk buffers, or freeing the memory occupied by transient |
7 | * tuples). Slots also provide access abstraction that lets us implement |
8 | * "virtual" tuples to reduce data-copying overhead. |
9 | * |
10 | * Routines dealing with the type information for tuples. Currently, |
11 | * the type information for a tuple is an array of FormData_pg_attribute. |
12 | * This information is needed by routines manipulating tuples |
13 | * (getattribute, formtuple, etc.). |
14 | * |
15 | * |
16 | * EXAMPLE OF HOW TABLE ROUTINES WORK |
17 | * Suppose we have a query such as SELECT emp.name FROM emp and we have |
18 | * a single SeqScan node in the query plan. |
19 | * |
20 | * At ExecutorStart() |
21 | * ---------------- |
22 | |
23 | * - ExecInitSeqScan() calls ExecInitScanTupleSlot() to construct a |
24 | * TupleTableSlots for the tuples returned by the access method, and |
25 | * ExecInitResultTypeTL() to define the node's return |
26 | * type. ExecAssignScanProjectionInfo() will, if necessary, create |
27 | * another TupleTableSlot for the tuples resulting from performing |
28 | * target list projections. |
29 | * |
30 | * During ExecutorRun() |
31 | * ---------------- |
32 | * - SeqNext() calls ExecStoreBufferHeapTuple() to place the tuple |
33 | * returned by the access method into the scan tuple slot. |
34 | * |
35 | * - ExecSeqScan() (via ExecScan), if necessary, calls ExecProject(), |
36 | * putting the result of the projection in the result tuple slot. If |
37 | * not necessary, it directly returns the slot returned by SeqNext(). |
38 | * |
39 | * - ExecutePlan() calls the output function. |
40 | * |
41 | * The important thing to watch in the executor code is how pointers |
42 | * to the slots containing tuples are passed instead of the tuples |
43 | * themselves. This facilitates the communication of related information |
44 | * (such as whether or not a tuple should be pfreed, what buffer contains |
45 | * this tuple, the tuple's tuple descriptor, etc). It also allows us |
46 | * to avoid physically constructing projection tuples in many cases. |
47 | * |
48 | * |
49 | * Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group |
50 | * Portions Copyright (c) 1994, Regents of the University of California |
51 | * |
52 | * |
53 | * IDENTIFICATION |
54 | * src/backend/executor/execTuples.c |
55 | * |
56 | *------------------------------------------------------------------------- |
57 | */ |
58 | #include "postgres.h" |
59 | |
60 | #include "access/htup_details.h" |
61 | #include "access/tupdesc_details.h" |
62 | #include "access/tuptoaster.h" |
63 | #include "funcapi.h" |
64 | #include "catalog/pg_type.h" |
65 | #include "nodes/nodeFuncs.h" |
66 | #include "storage/bufmgr.h" |
67 | #include "utils/builtins.h" |
68 | #include "utils/lsyscache.h" |
69 | #include "utils/typcache.h" |
70 | |
71 | |
72 | static TupleDesc ExecTypeFromTLInternal(List *targetList, |
73 | bool skipjunk); |
74 | static pg_attribute_always_inline void slot_deform_heap_tuple(TupleTableSlot *slot, HeapTuple tuple, uint32 *offp, |
75 | int natts); |
76 | static inline void tts_buffer_heap_store_tuple(TupleTableSlot *slot, |
77 | HeapTuple tuple, |
78 | Buffer buffer, |
79 | bool transfer_pin); |
80 | static void tts_heap_store_tuple(TupleTableSlot *slot, HeapTuple tuple, bool shouldFree); |
81 | |
82 | |
83 | const TupleTableSlotOps TTSOpsVirtual; |
84 | const TupleTableSlotOps TTSOpsHeapTuple; |
85 | const TupleTableSlotOps TTSOpsMinimalTuple; |
86 | const TupleTableSlotOps TTSOpsBufferHeapTuple; |
87 | |
88 | |
89 | /* |
90 | * TupleTableSlotOps implementations. |
91 | */ |
92 | |
93 | /* |
94 | * TupleTableSlotOps implementation for VirtualTupleTableSlot. |
95 | */ |
96 | static void |
97 | tts_virtual_init(TupleTableSlot *slot) |
98 | { |
99 | } |
100 | |
101 | static void |
102 | tts_virtual_release(TupleTableSlot *slot) |
103 | { |
104 | } |
105 | |
106 | static void |
107 | tts_virtual_clear(TupleTableSlot *slot) |
108 | { |
109 | if (unlikely(TTS_SHOULDFREE(slot))) |
110 | { |
111 | VirtualTupleTableSlot *vslot = (VirtualTupleTableSlot *) slot; |
112 | |
113 | pfree(vslot->data); |
114 | vslot->data = NULL; |
115 | |
116 | slot->tts_flags &= ~TTS_FLAG_SHOULDFREE; |
117 | } |
118 | |
119 | slot->tts_nvalid = 0; |
120 | slot->tts_flags |= TTS_FLAG_EMPTY; |
121 | ItemPointerSetInvalid(&slot->tts_tid); |
122 | } |
123 | |
124 | /* |
125 | * Attribute values are readily available in tts_values and tts_isnull array |
126 | * in a VirtualTupleTableSlot. So there should be no need to call either of the |
127 | * following two functions. |
128 | */ |
129 | static void |
130 | tts_virtual_getsomeattrs(TupleTableSlot *slot, int natts) |
131 | { |
132 | elog(ERROR, "getsomeattrs is not required to be called on a virtual tuple table slot" ); |
133 | } |
134 | |
135 | static Datum |
136 | tts_virtual_getsysattr(TupleTableSlot *slot, int attnum, bool *isnull) |
137 | { |
138 | elog(ERROR, "virtual tuple table slot does not have system attributes" ); |
139 | |
140 | return 0; /* silence compiler warnings */ |
141 | } |
142 | |
143 | /* |
144 | * To materialize a virtual slot all the datums that aren't passed by value |
145 | * have to be copied into the slot's memory context. To do so, compute the |
146 | * required size, and allocate enough memory to store all attributes. That's |
147 | * good for cache hit ratio, but more importantly requires only memory |
148 | * allocation/deallocation. |
149 | */ |
150 | static void |
151 | tts_virtual_materialize(TupleTableSlot *slot) |
152 | { |
153 | VirtualTupleTableSlot *vslot = (VirtualTupleTableSlot *) slot; |
154 | TupleDesc desc = slot->tts_tupleDescriptor; |
155 | Size sz = 0; |
156 | char *data; |
157 | |
158 | /* already materialized */ |
159 | if (TTS_SHOULDFREE(slot)) |
160 | return; |
161 | |
162 | /* compute size of memory required */ |
163 | for (int natt = 0; natt < desc->natts; natt++) |
164 | { |
165 | Form_pg_attribute att = TupleDescAttr(desc, natt); |
166 | Datum val; |
167 | |
168 | if (att->attbyval || slot->tts_isnull[natt]) |
169 | continue; |
170 | |
171 | val = slot->tts_values[natt]; |
172 | |
173 | if (att->attlen == -1 && |
174 | VARATT_IS_EXTERNAL_EXPANDED(DatumGetPointer(val))) |
175 | { |
176 | /* |
177 | * We want to flatten the expanded value so that the materialized |
178 | * slot doesn't depend on it. |
179 | */ |
180 | sz = att_align_nominal(sz, att->attalign); |
181 | sz += EOH_get_flat_size(DatumGetEOHP(val)); |
182 | } |
183 | else |
184 | { |
185 | sz = att_align_nominal(sz, att->attalign); |
186 | sz = att_addlength_datum(sz, att->attlen, val); |
187 | } |
188 | } |
189 | |
190 | /* all data is byval */ |
191 | if (sz == 0) |
192 | return; |
193 | |
194 | /* allocate memory */ |
195 | vslot->data = data = MemoryContextAlloc(slot->tts_mcxt, sz); |
196 | slot->tts_flags |= TTS_FLAG_SHOULDFREE; |
197 | |
198 | /* and copy all attributes into the pre-allocated space */ |
199 | for (int natt = 0; natt < desc->natts; natt++) |
200 | { |
201 | Form_pg_attribute att = TupleDescAttr(desc, natt); |
202 | Datum val; |
203 | |
204 | if (att->attbyval || slot->tts_isnull[natt]) |
205 | continue; |
206 | |
207 | val = slot->tts_values[natt]; |
208 | |
209 | if (att->attlen == -1 && |
210 | VARATT_IS_EXTERNAL_EXPANDED(DatumGetPointer(val))) |
211 | { |
212 | Size data_length; |
213 | |
214 | /* |
215 | * We want to flatten the expanded value so that the materialized |
216 | * slot doesn't depend on it. |
217 | */ |
218 | ExpandedObjectHeader *eoh = DatumGetEOHP(val); |
219 | |
220 | data = (char *) att_align_nominal(data, |
221 | att->attalign); |
222 | data_length = EOH_get_flat_size(eoh); |
223 | EOH_flatten_into(eoh, data, data_length); |
224 | |
225 | slot->tts_values[natt] = PointerGetDatum(data); |
226 | data += data_length; |
227 | } |
228 | else |
229 | { |
230 | Size data_length = 0; |
231 | |
232 | data = (char *) att_align_nominal(data, att->attalign); |
233 | data_length = att_addlength_datum(data_length, att->attlen, val); |
234 | |
235 | memcpy(data, DatumGetPointer(val), data_length); |
236 | |
237 | slot->tts_values[natt] = PointerGetDatum(data); |
238 | data += data_length; |
239 | } |
240 | } |
241 | } |
242 | |
243 | static void |
244 | tts_virtual_copyslot(TupleTableSlot *dstslot, TupleTableSlot *srcslot) |
245 | { |
246 | TupleDesc srcdesc = srcslot->tts_tupleDescriptor; |
247 | |
248 | Assert(srcdesc->natts <= dstslot->tts_tupleDescriptor->natts); |
249 | |
250 | tts_virtual_clear(dstslot); |
251 | |
252 | slot_getallattrs(srcslot); |
253 | |
254 | for (int natt = 0; natt < srcdesc->natts; natt++) |
255 | { |
256 | dstslot->tts_values[natt] = srcslot->tts_values[natt]; |
257 | dstslot->tts_isnull[natt] = srcslot->tts_isnull[natt]; |
258 | } |
259 | |
260 | dstslot->tts_nvalid = srcdesc->natts; |
261 | dstslot->tts_flags &= ~TTS_FLAG_EMPTY; |
262 | |
263 | /* make sure storage doesn't depend on external memory */ |
264 | tts_virtual_materialize(dstslot); |
265 | } |
266 | |
267 | static HeapTuple |
268 | tts_virtual_copy_heap_tuple(TupleTableSlot *slot) |
269 | { |
270 | Assert(!TTS_EMPTY(slot)); |
271 | |
272 | return heap_form_tuple(slot->tts_tupleDescriptor, |
273 | slot->tts_values, |
274 | slot->tts_isnull); |
275 | |
276 | } |
277 | |
278 | static MinimalTuple |
279 | tts_virtual_copy_minimal_tuple(TupleTableSlot *slot) |
280 | { |
281 | Assert(!TTS_EMPTY(slot)); |
282 | |
283 | return heap_form_minimal_tuple(slot->tts_tupleDescriptor, |
284 | slot->tts_values, |
285 | slot->tts_isnull); |
286 | } |
287 | |
288 | |
289 | /* |
290 | * TupleTableSlotOps implementation for HeapTupleTableSlot. |
291 | */ |
292 | |
293 | static void |
294 | tts_heap_init(TupleTableSlot *slot) |
295 | { |
296 | } |
297 | |
298 | static void |
299 | tts_heap_release(TupleTableSlot *slot) |
300 | { |
301 | } |
302 | |
303 | static void |
304 | tts_heap_clear(TupleTableSlot *slot) |
305 | { |
306 | HeapTupleTableSlot *hslot = (HeapTupleTableSlot *) slot; |
307 | |
308 | /* Free the memory for the heap tuple if it's allowed. */ |
309 | if (TTS_SHOULDFREE(slot)) |
310 | { |
311 | heap_freetuple(hslot->tuple); |
312 | slot->tts_flags &= ~TTS_FLAG_SHOULDFREE; |
313 | } |
314 | |
315 | slot->tts_nvalid = 0; |
316 | slot->tts_flags |= TTS_FLAG_EMPTY; |
317 | ItemPointerSetInvalid(&slot->tts_tid); |
318 | hslot->off = 0; |
319 | hslot->tuple = NULL; |
320 | } |
321 | |
322 | static void |
323 | tts_heap_getsomeattrs(TupleTableSlot *slot, int natts) |
324 | { |
325 | HeapTupleTableSlot *hslot = (HeapTupleTableSlot *) slot; |
326 | |
327 | Assert(!TTS_EMPTY(slot)); |
328 | |
329 | slot_deform_heap_tuple(slot, hslot->tuple, &hslot->off, natts); |
330 | } |
331 | |
332 | static Datum |
333 | tts_heap_getsysattr(TupleTableSlot *slot, int attnum, bool *isnull) |
334 | { |
335 | HeapTupleTableSlot *hslot = (HeapTupleTableSlot *) slot; |
336 | |
337 | return heap_getsysattr(hslot->tuple, attnum, |
338 | slot->tts_tupleDescriptor, isnull); |
339 | } |
340 | |
341 | static void |
342 | tts_heap_materialize(TupleTableSlot *slot) |
343 | { |
344 | HeapTupleTableSlot *hslot = (HeapTupleTableSlot *) slot; |
345 | MemoryContext oldContext; |
346 | |
347 | Assert(!TTS_EMPTY(slot)); |
348 | |
349 | /* This slot has it's tuple already materialized. Nothing to do. */ |
350 | if (TTS_SHOULDFREE(slot)) |
351 | return; |
352 | |
353 | slot->tts_flags |= TTS_FLAG_SHOULDFREE; |
354 | |
355 | oldContext = MemoryContextSwitchTo(slot->tts_mcxt); |
356 | |
357 | if (!hslot->tuple) |
358 | hslot->tuple = heap_form_tuple(slot->tts_tupleDescriptor, |
359 | slot->tts_values, |
360 | slot->tts_isnull); |
361 | else |
362 | { |
363 | /* |
364 | * The tuple contained in this slot is not allocated in the memory |
365 | * context of the given slot (else it would have TTS_SHOULDFREE set). |
366 | * Copy the tuple into the given slot's memory context. |
367 | */ |
368 | hslot->tuple = heap_copytuple(hslot->tuple); |
369 | } |
370 | |
371 | /* |
372 | * Have to deform from scratch, otherwise tts_values[] entries could point |
373 | * into the non-materialized tuple (which might be gone when accessed). |
374 | */ |
375 | slot->tts_nvalid = 0; |
376 | hslot->off = 0; |
377 | |
378 | MemoryContextSwitchTo(oldContext); |
379 | } |
380 | |
381 | static void |
382 | tts_heap_copyslot(TupleTableSlot *dstslot, TupleTableSlot *srcslot) |
383 | { |
384 | HeapTuple tuple; |
385 | MemoryContext oldcontext; |
386 | |
387 | oldcontext = MemoryContextSwitchTo(dstslot->tts_mcxt); |
388 | tuple = ExecCopySlotHeapTuple(srcslot); |
389 | MemoryContextSwitchTo(oldcontext); |
390 | |
391 | ExecStoreHeapTuple(tuple, dstslot, true); |
392 | } |
393 | |
394 | static HeapTuple |
395 | tts_heap_get_heap_tuple(TupleTableSlot *slot) |
396 | { |
397 | HeapTupleTableSlot *hslot = (HeapTupleTableSlot *) slot; |
398 | |
399 | Assert(!TTS_EMPTY(slot)); |
400 | if (!hslot->tuple) |
401 | tts_heap_materialize(slot); |
402 | |
403 | return hslot->tuple; |
404 | } |
405 | |
406 | static HeapTuple |
407 | tts_heap_copy_heap_tuple(TupleTableSlot *slot) |
408 | { |
409 | HeapTupleTableSlot *hslot = (HeapTupleTableSlot *) slot; |
410 | |
411 | Assert(!TTS_EMPTY(slot)); |
412 | if (!hslot->tuple) |
413 | tts_heap_materialize(slot); |
414 | |
415 | return heap_copytuple(hslot->tuple); |
416 | } |
417 | |
418 | static MinimalTuple |
419 | tts_heap_copy_minimal_tuple(TupleTableSlot *slot) |
420 | { |
421 | HeapTupleTableSlot *hslot = (HeapTupleTableSlot *) slot; |
422 | |
423 | if (!hslot->tuple) |
424 | tts_heap_materialize(slot); |
425 | |
426 | return minimal_tuple_from_heap_tuple(hslot->tuple); |
427 | } |
428 | |
429 | static void |
430 | tts_heap_store_tuple(TupleTableSlot *slot, HeapTuple tuple, bool shouldFree) |
431 | { |
432 | HeapTupleTableSlot *hslot = (HeapTupleTableSlot *) slot; |
433 | |
434 | tts_heap_clear(slot); |
435 | |
436 | slot->tts_nvalid = 0; |
437 | hslot->tuple = tuple; |
438 | hslot->off = 0; |
439 | slot->tts_flags &= ~TTS_FLAG_EMPTY; |
440 | slot->tts_tid = tuple->t_self; |
441 | |
442 | if (shouldFree) |
443 | slot->tts_flags |= TTS_FLAG_SHOULDFREE; |
444 | } |
445 | |
446 | |
447 | /* |
448 | * TupleTableSlotOps implementation for MinimalTupleTableSlot. |
449 | */ |
450 | |
451 | static void |
452 | tts_minimal_init(TupleTableSlot *slot) |
453 | { |
454 | MinimalTupleTableSlot *mslot = (MinimalTupleTableSlot *) slot; |
455 | |
456 | /* |
457 | * Initialize the heap tuple pointer to access attributes of the minimal |
458 | * tuple contained in the slot as if its a heap tuple. |
459 | */ |
460 | mslot->tuple = &mslot->minhdr; |
461 | } |
462 | |
463 | static void |
464 | tts_minimal_release(TupleTableSlot *slot) |
465 | { |
466 | } |
467 | |
468 | static void |
469 | tts_minimal_clear(TupleTableSlot *slot) |
470 | { |
471 | MinimalTupleTableSlot *mslot = (MinimalTupleTableSlot *) slot; |
472 | |
473 | if (TTS_SHOULDFREE(slot)) |
474 | { |
475 | heap_free_minimal_tuple(mslot->mintuple); |
476 | slot->tts_flags &= ~TTS_FLAG_SHOULDFREE; |
477 | } |
478 | |
479 | slot->tts_nvalid = 0; |
480 | slot->tts_flags |= TTS_FLAG_EMPTY; |
481 | ItemPointerSetInvalid(&slot->tts_tid); |
482 | mslot->off = 0; |
483 | mslot->mintuple = NULL; |
484 | } |
485 | |
486 | static void |
487 | tts_minimal_getsomeattrs(TupleTableSlot *slot, int natts) |
488 | { |
489 | MinimalTupleTableSlot *mslot = (MinimalTupleTableSlot *) slot; |
490 | |
491 | Assert(!TTS_EMPTY(slot)); |
492 | |
493 | slot_deform_heap_tuple(slot, mslot->tuple, &mslot->off, natts); |
494 | } |
495 | |
496 | static Datum |
497 | tts_minimal_getsysattr(TupleTableSlot *slot, int attnum, bool *isnull) |
498 | { |
499 | elog(ERROR, "minimal tuple table slot does not have system attributes" ); |
500 | |
501 | return 0; /* silence compiler warnings */ |
502 | } |
503 | |
504 | static void |
505 | tts_minimal_materialize(TupleTableSlot *slot) |
506 | { |
507 | MinimalTupleTableSlot *mslot = (MinimalTupleTableSlot *) slot; |
508 | MemoryContext oldContext; |
509 | |
510 | Assert(!TTS_EMPTY(slot)); |
511 | |
512 | /* This slot has it's tuple already materialized. Nothing to do. */ |
513 | if (TTS_SHOULDFREE(slot)) |
514 | return; |
515 | |
516 | slot->tts_flags |= TTS_FLAG_SHOULDFREE; |
517 | oldContext = MemoryContextSwitchTo(slot->tts_mcxt); |
518 | |
519 | if (!mslot->mintuple) |
520 | { |
521 | mslot->mintuple = heap_form_minimal_tuple(slot->tts_tupleDescriptor, |
522 | slot->tts_values, |
523 | slot->tts_isnull); |
524 | } |
525 | else |
526 | { |
527 | /* |
528 | * The minimal tuple contained in this slot is not allocated in the |
529 | * memory context of the given slot (else it would have TTS_SHOULDFREE |
530 | * set). Copy the minimal tuple into the given slot's memory context. |
531 | */ |
532 | mslot->mintuple = heap_copy_minimal_tuple(mslot->mintuple); |
533 | } |
534 | |
535 | Assert(mslot->tuple == &mslot->minhdr); |
536 | |
537 | mslot->minhdr.t_len = mslot->mintuple->t_len + MINIMAL_TUPLE_OFFSET; |
538 | mslot->minhdr.t_data = (HeapTupleHeader) ((char *) mslot->mintuple - MINIMAL_TUPLE_OFFSET); |
539 | |
540 | MemoryContextSwitchTo(oldContext); |
541 | |
542 | /* |
543 | * Have to deform from scratch, otherwise tts_values[] entries could point |
544 | * into the non-materialized tuple (which might be gone when accessed). |
545 | */ |
546 | slot->tts_nvalid = 0; |
547 | mslot->off = 0; |
548 | } |
549 | |
550 | static void |
551 | tts_minimal_copyslot(TupleTableSlot *dstslot, TupleTableSlot *srcslot) |
552 | { |
553 | MemoryContext oldcontext; |
554 | MinimalTuple mintuple; |
555 | |
556 | oldcontext = MemoryContextSwitchTo(dstslot->tts_mcxt); |
557 | mintuple = ExecCopySlotMinimalTuple(srcslot); |
558 | MemoryContextSwitchTo(oldcontext); |
559 | |
560 | ExecStoreMinimalTuple(mintuple, dstslot, true); |
561 | } |
562 | |
563 | static MinimalTuple |
564 | tts_minimal_get_minimal_tuple(TupleTableSlot *slot) |
565 | { |
566 | MinimalTupleTableSlot *mslot = (MinimalTupleTableSlot *) slot; |
567 | |
568 | if (!mslot->mintuple) |
569 | tts_minimal_materialize(slot); |
570 | |
571 | return mslot->mintuple; |
572 | } |
573 | |
574 | static HeapTuple |
575 | tts_minimal_copy_heap_tuple(TupleTableSlot *slot) |
576 | { |
577 | MinimalTupleTableSlot *mslot = (MinimalTupleTableSlot *) slot; |
578 | |
579 | if (!mslot->mintuple) |
580 | tts_minimal_materialize(slot); |
581 | |
582 | return heap_tuple_from_minimal_tuple(mslot->mintuple); |
583 | } |
584 | |
585 | static MinimalTuple |
586 | tts_minimal_copy_minimal_tuple(TupleTableSlot *slot) |
587 | { |
588 | MinimalTupleTableSlot *mslot = (MinimalTupleTableSlot *) slot; |
589 | |
590 | if (!mslot->mintuple) |
591 | tts_minimal_materialize(slot); |
592 | |
593 | return heap_copy_minimal_tuple(mslot->mintuple); |
594 | } |
595 | |
596 | static void |
597 | tts_minimal_store_tuple(TupleTableSlot *slot, MinimalTuple mtup, bool shouldFree) |
598 | { |
599 | MinimalTupleTableSlot *mslot = (MinimalTupleTableSlot *) slot; |
600 | |
601 | tts_minimal_clear(slot); |
602 | |
603 | Assert(!TTS_SHOULDFREE(slot)); |
604 | Assert(TTS_EMPTY(slot)); |
605 | |
606 | slot->tts_flags &= ~TTS_FLAG_EMPTY; |
607 | slot->tts_nvalid = 0; |
608 | mslot->off = 0; |
609 | |
610 | mslot->mintuple = mtup; |
611 | Assert(mslot->tuple == &mslot->minhdr); |
612 | mslot->minhdr.t_len = mtup->t_len + MINIMAL_TUPLE_OFFSET; |
613 | mslot->minhdr.t_data = (HeapTupleHeader) ((char *) mtup - MINIMAL_TUPLE_OFFSET); |
614 | /* no need to set t_self or t_tableOid since we won't allow access */ |
615 | |
616 | if (shouldFree) |
617 | slot->tts_flags |= TTS_FLAG_SHOULDFREE; |
618 | else |
619 | Assert(!TTS_SHOULDFREE(slot)); |
620 | } |
621 | |
622 | |
623 | /* |
624 | * TupleTableSlotOps implementation for BufferHeapTupleTableSlot. |
625 | */ |
626 | |
627 | static void |
628 | tts_buffer_heap_init(TupleTableSlot *slot) |
629 | { |
630 | } |
631 | |
632 | static void |
633 | tts_buffer_heap_release(TupleTableSlot *slot) |
634 | { |
635 | } |
636 | |
637 | static void |
638 | tts_buffer_heap_clear(TupleTableSlot *slot) |
639 | { |
640 | BufferHeapTupleTableSlot *bslot = (BufferHeapTupleTableSlot *) slot; |
641 | |
642 | /* |
643 | * Free the memory for heap tuple if allowed. A tuple coming from buffer |
644 | * can never be freed. But we may have materialized a tuple from buffer. |
645 | * Such a tuple can be freed. |
646 | */ |
647 | if (TTS_SHOULDFREE(slot)) |
648 | { |
649 | /* We should have unpinned the buffer while materializing the tuple. */ |
650 | Assert(!BufferIsValid(bslot->buffer)); |
651 | |
652 | heap_freetuple(bslot->base.tuple); |
653 | slot->tts_flags &= ~TTS_FLAG_SHOULDFREE; |
654 | |
655 | Assert(!BufferIsValid(bslot->buffer)); |
656 | } |
657 | |
658 | if (BufferIsValid(bslot->buffer)) |
659 | ReleaseBuffer(bslot->buffer); |
660 | |
661 | slot->tts_nvalid = 0; |
662 | slot->tts_flags |= TTS_FLAG_EMPTY; |
663 | ItemPointerSetInvalid(&slot->tts_tid); |
664 | bslot->base.tuple = NULL; |
665 | bslot->base.off = 0; |
666 | bslot->buffer = InvalidBuffer; |
667 | } |
668 | |
669 | static void |
670 | tts_buffer_heap_getsomeattrs(TupleTableSlot *slot, int natts) |
671 | { |
672 | BufferHeapTupleTableSlot *bslot = (BufferHeapTupleTableSlot *) slot; |
673 | |
674 | Assert(!TTS_EMPTY(slot)); |
675 | |
676 | slot_deform_heap_tuple(slot, bslot->base.tuple, &bslot->base.off, natts); |
677 | } |
678 | |
679 | static Datum |
680 | tts_buffer_heap_getsysattr(TupleTableSlot *slot, int attnum, bool *isnull) |
681 | { |
682 | BufferHeapTupleTableSlot *bslot = (BufferHeapTupleTableSlot *) slot; |
683 | |
684 | return heap_getsysattr(bslot->base.tuple, attnum, |
685 | slot->tts_tupleDescriptor, isnull); |
686 | } |
687 | |
688 | static void |
689 | tts_buffer_heap_materialize(TupleTableSlot *slot) |
690 | { |
691 | BufferHeapTupleTableSlot *bslot = (BufferHeapTupleTableSlot *) slot; |
692 | MemoryContext oldContext; |
693 | |
694 | Assert(!TTS_EMPTY(slot)); |
695 | |
696 | /* If already materialized nothing to do. */ |
697 | if (TTS_SHOULDFREE(slot)) |
698 | return; |
699 | |
700 | slot->tts_flags |= TTS_FLAG_SHOULDFREE; |
701 | |
702 | oldContext = MemoryContextSwitchTo(slot->tts_mcxt); |
703 | |
704 | if (!bslot->base.tuple) |
705 | { |
706 | /* |
707 | * Normally BufferHeapTupleTableSlot should have a tuple + buffer |
708 | * associated with it, unless it's materialized (which would've |
709 | * returned above). But when it's useful to allow storing virtual |
710 | * tuples in a buffer slot, which then also needs to be |
711 | * materializable. |
712 | */ |
713 | bslot->base.tuple = heap_form_tuple(slot->tts_tupleDescriptor, |
714 | slot->tts_values, |
715 | slot->tts_isnull); |
716 | |
717 | } |
718 | else |
719 | { |
720 | bslot->base.tuple = heap_copytuple(bslot->base.tuple); |
721 | |
722 | /* |
723 | * A heap tuple stored in a BufferHeapTupleTableSlot should have a |
724 | * buffer associated with it, unless it's materialized or virtual. |
725 | */ |
726 | Assert(BufferIsValid(bslot->buffer)); |
727 | if (likely(BufferIsValid(bslot->buffer))) |
728 | ReleaseBuffer(bslot->buffer); |
729 | bslot->buffer = InvalidBuffer; |
730 | } |
731 | MemoryContextSwitchTo(oldContext); |
732 | |
733 | /* |
734 | * Have to deform from scratch, otherwise tts_values[] entries could point |
735 | * into the non-materialized tuple (which might be gone when accessed). |
736 | */ |
737 | bslot->base.off = 0; |
738 | slot->tts_nvalid = 0; |
739 | } |
740 | |
741 | static void |
742 | tts_buffer_heap_copyslot(TupleTableSlot *dstslot, TupleTableSlot *srcslot) |
743 | { |
744 | BufferHeapTupleTableSlot *bsrcslot = (BufferHeapTupleTableSlot *) srcslot; |
745 | BufferHeapTupleTableSlot *bdstslot = (BufferHeapTupleTableSlot *) dstslot; |
746 | |
747 | /* |
748 | * If the source slot is of a different kind, or is a buffer slot that has |
749 | * been materialized / is virtual, make a new copy of the tuple. Otherwise |
750 | * make a new reference to the in-buffer tuple. |
751 | */ |
752 | if (dstslot->tts_ops != srcslot->tts_ops || |
753 | TTS_SHOULDFREE(srcslot) || |
754 | !bsrcslot->base.tuple) |
755 | { |
756 | MemoryContext oldContext; |
757 | |
758 | ExecClearTuple(dstslot); |
759 | dstslot->tts_flags |= TTS_FLAG_SHOULDFREE; |
760 | dstslot->tts_flags &= ~TTS_FLAG_EMPTY; |
761 | oldContext = MemoryContextSwitchTo(dstslot->tts_mcxt); |
762 | bdstslot->base.tuple = ExecCopySlotHeapTuple(srcslot); |
763 | MemoryContextSwitchTo(oldContext); |
764 | } |
765 | else |
766 | { |
767 | Assert(BufferIsValid(bsrcslot->buffer)); |
768 | |
769 | tts_buffer_heap_store_tuple(dstslot, bsrcslot->base.tuple, |
770 | bsrcslot->buffer, false); |
771 | |
772 | /* |
773 | * The HeapTupleData portion of the source tuple might be shorter |
774 | * lived than the destination slot. Therefore copy the HeapTuple into |
775 | * our slot's tupdata, which is guaranteed to live long enough (but |
776 | * will still point into the buffer). |
777 | */ |
778 | memcpy(&bdstslot->base.tupdata, bdstslot->base.tuple, sizeof(HeapTupleData)); |
779 | bdstslot->base.tuple = &bdstslot->base.tupdata; |
780 | } |
781 | } |
782 | |
783 | static HeapTuple |
784 | tts_buffer_heap_get_heap_tuple(TupleTableSlot *slot) |
785 | { |
786 | BufferHeapTupleTableSlot *bslot = (BufferHeapTupleTableSlot *) slot; |
787 | |
788 | Assert(!TTS_EMPTY(slot)); |
789 | |
790 | if (!bslot->base.tuple) |
791 | tts_buffer_heap_materialize(slot); |
792 | |
793 | return bslot->base.tuple; |
794 | } |
795 | |
796 | static HeapTuple |
797 | tts_buffer_heap_copy_heap_tuple(TupleTableSlot *slot) |
798 | { |
799 | BufferHeapTupleTableSlot *bslot = (BufferHeapTupleTableSlot *) slot; |
800 | |
801 | Assert(!TTS_EMPTY(slot)); |
802 | |
803 | if (!bslot->base.tuple) |
804 | tts_buffer_heap_materialize(slot); |
805 | |
806 | return heap_copytuple(bslot->base.tuple); |
807 | } |
808 | |
809 | static MinimalTuple |
810 | tts_buffer_heap_copy_minimal_tuple(TupleTableSlot *slot) |
811 | { |
812 | BufferHeapTupleTableSlot *bslot = (BufferHeapTupleTableSlot *) slot; |
813 | |
814 | Assert(!TTS_EMPTY(slot)); |
815 | |
816 | if (!bslot->base.tuple) |
817 | tts_buffer_heap_materialize(slot); |
818 | |
819 | return minimal_tuple_from_heap_tuple(bslot->base.tuple); |
820 | } |
821 | |
822 | static inline void |
823 | tts_buffer_heap_store_tuple(TupleTableSlot *slot, HeapTuple tuple, |
824 | Buffer buffer, bool transfer_pin) |
825 | { |
826 | BufferHeapTupleTableSlot *bslot = (BufferHeapTupleTableSlot *) slot; |
827 | |
828 | if (TTS_SHOULDFREE(slot)) |
829 | { |
830 | /* materialized slot shouldn't have a buffer to release */ |
831 | Assert(!BufferIsValid(bslot->buffer)); |
832 | |
833 | heap_freetuple(bslot->base.tuple); |
834 | slot->tts_flags &= ~TTS_FLAG_SHOULDFREE; |
835 | } |
836 | |
837 | slot->tts_flags &= ~TTS_FLAG_EMPTY; |
838 | slot->tts_nvalid = 0; |
839 | bslot->base.tuple = tuple; |
840 | bslot->base.off = 0; |
841 | slot->tts_tid = tuple->t_self; |
842 | |
843 | /* |
844 | * If tuple is on a disk page, keep the page pinned as long as we hold a |
845 | * pointer into it. We assume the caller already has such a pin. If |
846 | * transfer_pin is true, we'll transfer that pin to this slot, if not |
847 | * we'll pin it again ourselves. |
848 | * |
849 | * This is coded to optimize the case where the slot previously held a |
850 | * tuple on the same disk page: in that case releasing and re-acquiring |
851 | * the pin is a waste of cycles. This is a common situation during |
852 | * seqscans, so it's worth troubling over. |
853 | */ |
854 | if (bslot->buffer != buffer) |
855 | { |
856 | if (BufferIsValid(bslot->buffer)) |
857 | ReleaseBuffer(bslot->buffer); |
858 | |
859 | bslot->buffer = buffer; |
860 | |
861 | if (!transfer_pin && BufferIsValid(buffer)) |
862 | IncrBufferRefCount(buffer); |
863 | } |
864 | else if (transfer_pin && BufferIsValid(buffer)) |
865 | { |
866 | /* |
867 | * In transfer_pin mode the caller won't know about the same-page |
868 | * optimization, so we gotta release its pin. |
869 | */ |
870 | ReleaseBuffer(buffer); |
871 | } |
872 | } |
873 | |
874 | /* |
875 | * slot_deform_heap_tuple |
876 | * Given a TupleTableSlot, extract data from the slot's physical tuple |
877 | * into its Datum/isnull arrays. Data is extracted up through the |
878 | * natts'th column (caller must ensure this is a legal column number). |
879 | * |
880 | * This is essentially an incremental version of heap_deform_tuple: |
881 | * on each call we extract attributes up to the one needed, without |
882 | * re-computing information about previously extracted attributes. |
883 | * slot->tts_nvalid is the number of attributes already extracted. |
884 | * |
885 | * This is marked as always inline, so the different offp for different types |
886 | * of slots gets optimized away. |
887 | */ |
888 | static pg_attribute_always_inline void |
889 | slot_deform_heap_tuple(TupleTableSlot *slot, HeapTuple tuple, uint32 *offp, |
890 | int natts) |
891 | { |
892 | TupleDesc tupleDesc = slot->tts_tupleDescriptor; |
893 | Datum *values = slot->tts_values; |
894 | bool *isnull = slot->tts_isnull; |
895 | HeapTupleHeader tup = tuple->t_data; |
896 | bool hasnulls = HeapTupleHasNulls(tuple); |
897 | int attnum; |
898 | char *tp; /* ptr to tuple data */ |
899 | uint32 off; /* offset in tuple data */ |
900 | bits8 *bp = tup->t_bits; /* ptr to null bitmap in tuple */ |
901 | bool slow; /* can we use/set attcacheoff? */ |
902 | |
903 | /* We can only fetch as many attributes as the tuple has. */ |
904 | natts = Min(HeapTupleHeaderGetNatts(tuple->t_data), natts); |
905 | |
906 | /* |
907 | * Check whether the first call for this tuple, and initialize or restore |
908 | * loop state. |
909 | */ |
910 | attnum = slot->tts_nvalid; |
911 | if (attnum == 0) |
912 | { |
913 | /* Start from the first attribute */ |
914 | off = 0; |
915 | slow = false; |
916 | } |
917 | else |
918 | { |
919 | /* Restore state from previous execution */ |
920 | off = *offp; |
921 | slow = TTS_SLOW(slot); |
922 | } |
923 | |
924 | tp = (char *) tup + tup->t_hoff; |
925 | |
926 | for (; attnum < natts; attnum++) |
927 | { |
928 | Form_pg_attribute thisatt = TupleDescAttr(tupleDesc, attnum); |
929 | |
930 | if (hasnulls && att_isnull(attnum, bp)) |
931 | { |
932 | values[attnum] = (Datum) 0; |
933 | isnull[attnum] = true; |
934 | slow = true; /* can't use attcacheoff anymore */ |
935 | continue; |
936 | } |
937 | |
938 | isnull[attnum] = false; |
939 | |
940 | if (!slow && thisatt->attcacheoff >= 0) |
941 | off = thisatt->attcacheoff; |
942 | else if (thisatt->attlen == -1) |
943 | { |
944 | /* |
945 | * We can only cache the offset for a varlena attribute if the |
946 | * offset is already suitably aligned, so that there would be no |
947 | * pad bytes in any case: then the offset will be valid for either |
948 | * an aligned or unaligned value. |
949 | */ |
950 | if (!slow && |
951 | off == att_align_nominal(off, thisatt->attalign)) |
952 | thisatt->attcacheoff = off; |
953 | else |
954 | { |
955 | off = att_align_pointer(off, thisatt->attalign, -1, |
956 | tp + off); |
957 | slow = true; |
958 | } |
959 | } |
960 | else |
961 | { |
962 | /* not varlena, so safe to use att_align_nominal */ |
963 | off = att_align_nominal(off, thisatt->attalign); |
964 | |
965 | if (!slow) |
966 | thisatt->attcacheoff = off; |
967 | } |
968 | |
969 | values[attnum] = fetchatt(thisatt, tp + off); |
970 | |
971 | off = att_addlength_pointer(off, thisatt->attlen, tp + off); |
972 | |
973 | if (thisatt->attlen <= 0) |
974 | slow = true; /* can't use attcacheoff anymore */ |
975 | } |
976 | |
977 | /* |
978 | * Save state for next execution |
979 | */ |
980 | slot->tts_nvalid = attnum; |
981 | *offp = off; |
982 | if (slow) |
983 | slot->tts_flags |= TTS_FLAG_SLOW; |
984 | else |
985 | slot->tts_flags &= ~TTS_FLAG_SLOW; |
986 | } |
987 | |
988 | |
989 | const TupleTableSlotOps TTSOpsVirtual = { |
990 | .base_slot_size = sizeof(VirtualTupleTableSlot), |
991 | .init = tts_virtual_init, |
992 | .release = tts_virtual_release, |
993 | .clear = tts_virtual_clear, |
994 | .getsomeattrs = tts_virtual_getsomeattrs, |
995 | .getsysattr = tts_virtual_getsysattr, |
996 | .materialize = tts_virtual_materialize, |
997 | .copyslot = tts_virtual_copyslot, |
998 | |
999 | /* |
1000 | * A virtual tuple table slot can not "own" a heap tuple or a minimal |
1001 | * tuple. |
1002 | */ |
1003 | .get_heap_tuple = NULL, |
1004 | .get_minimal_tuple = NULL, |
1005 | .copy_heap_tuple = tts_virtual_copy_heap_tuple, |
1006 | .copy_minimal_tuple = tts_virtual_copy_minimal_tuple |
1007 | }; |
1008 | |
1009 | const TupleTableSlotOps TTSOpsHeapTuple = { |
1010 | .base_slot_size = sizeof(HeapTupleTableSlot), |
1011 | .init = tts_heap_init, |
1012 | .release = tts_heap_release, |
1013 | .clear = tts_heap_clear, |
1014 | .getsomeattrs = tts_heap_getsomeattrs, |
1015 | .getsysattr = tts_heap_getsysattr, |
1016 | .materialize = tts_heap_materialize, |
1017 | .copyslot = tts_heap_copyslot, |
1018 | .get_heap_tuple = tts_heap_get_heap_tuple, |
1019 | |
1020 | /* A heap tuple table slot can not "own" a minimal tuple. */ |
1021 | .get_minimal_tuple = NULL, |
1022 | .copy_heap_tuple = tts_heap_copy_heap_tuple, |
1023 | .copy_minimal_tuple = tts_heap_copy_minimal_tuple |
1024 | }; |
1025 | |
1026 | const TupleTableSlotOps TTSOpsMinimalTuple = { |
1027 | .base_slot_size = sizeof(MinimalTupleTableSlot), |
1028 | .init = tts_minimal_init, |
1029 | .release = tts_minimal_release, |
1030 | .clear = tts_minimal_clear, |
1031 | .getsomeattrs = tts_minimal_getsomeattrs, |
1032 | .getsysattr = tts_minimal_getsysattr, |
1033 | .materialize = tts_minimal_materialize, |
1034 | .copyslot = tts_minimal_copyslot, |
1035 | |
1036 | /* A minimal tuple table slot can not "own" a heap tuple. */ |
1037 | .get_heap_tuple = NULL, |
1038 | .get_minimal_tuple = tts_minimal_get_minimal_tuple, |
1039 | .copy_heap_tuple = tts_minimal_copy_heap_tuple, |
1040 | .copy_minimal_tuple = tts_minimal_copy_minimal_tuple |
1041 | }; |
1042 | |
1043 | const TupleTableSlotOps TTSOpsBufferHeapTuple = { |
1044 | .base_slot_size = sizeof(BufferHeapTupleTableSlot), |
1045 | .init = tts_buffer_heap_init, |
1046 | .release = tts_buffer_heap_release, |
1047 | .clear = tts_buffer_heap_clear, |
1048 | .getsomeattrs = tts_buffer_heap_getsomeattrs, |
1049 | .getsysattr = tts_buffer_heap_getsysattr, |
1050 | .materialize = tts_buffer_heap_materialize, |
1051 | .copyslot = tts_buffer_heap_copyslot, |
1052 | .get_heap_tuple = tts_buffer_heap_get_heap_tuple, |
1053 | |
1054 | /* A buffer heap tuple table slot can not "own" a minimal tuple. */ |
1055 | .get_minimal_tuple = NULL, |
1056 | .copy_heap_tuple = tts_buffer_heap_copy_heap_tuple, |
1057 | .copy_minimal_tuple = tts_buffer_heap_copy_minimal_tuple |
1058 | }; |
1059 | |
1060 | |
1061 | /* ---------------------------------------------------------------- |
1062 | * tuple table create/delete functions |
1063 | * ---------------------------------------------------------------- |
1064 | */ |
1065 | |
1066 | /* -------------------------------- |
1067 | * MakeTupleTableSlot |
1068 | * |
1069 | * Basic routine to make an empty TupleTableSlot of given |
1070 | * TupleTableSlotType. If tupleDesc is specified the slot's descriptor is |
1071 | * fixed for its lifetime, gaining some efficiency. If that's |
1072 | * undesirable, pass NULL. |
1073 | * -------------------------------- |
1074 | */ |
1075 | TupleTableSlot * |
1076 | MakeTupleTableSlot(TupleDesc tupleDesc, |
1077 | const TupleTableSlotOps *tts_ops) |
1078 | { |
1079 | Size basesz, |
1080 | allocsz; |
1081 | TupleTableSlot *slot; |
1082 | |
1083 | basesz = tts_ops->base_slot_size; |
1084 | |
1085 | /* |
1086 | * When a fixed descriptor is specified, we can reduce overhead by |
1087 | * allocating the entire slot in one go. |
1088 | */ |
1089 | if (tupleDesc) |
1090 | allocsz = MAXALIGN(basesz) + |
1091 | MAXALIGN(tupleDesc->natts * sizeof(Datum)) + |
1092 | MAXALIGN(tupleDesc->natts * sizeof(bool)); |
1093 | else |
1094 | allocsz = basesz; |
1095 | |
1096 | slot = palloc0(allocsz); |
1097 | /* const for optimization purposes, OK to modify at allocation time */ |
1098 | *((const TupleTableSlotOps **) &slot->tts_ops) = tts_ops; |
1099 | slot->type = T_TupleTableSlot; |
1100 | slot->tts_flags |= TTS_FLAG_EMPTY; |
1101 | if (tupleDesc != NULL) |
1102 | slot->tts_flags |= TTS_FLAG_FIXED; |
1103 | slot->tts_tupleDescriptor = tupleDesc; |
1104 | slot->tts_mcxt = CurrentMemoryContext; |
1105 | slot->tts_nvalid = 0; |
1106 | |
1107 | if (tupleDesc != NULL) |
1108 | { |
1109 | slot->tts_values = (Datum *) |
1110 | (((char *) slot) |
1111 | + MAXALIGN(basesz)); |
1112 | slot->tts_isnull = (bool *) |
1113 | (((char *) slot) |
1114 | + MAXALIGN(basesz) |
1115 | + MAXALIGN(tupleDesc->natts * sizeof(Datum))); |
1116 | |
1117 | PinTupleDesc(tupleDesc); |
1118 | } |
1119 | |
1120 | /* |
1121 | * And allow slot type specific initialization. |
1122 | */ |
1123 | slot->tts_ops->init(slot); |
1124 | |
1125 | return slot; |
1126 | } |
1127 | |
1128 | /* -------------------------------- |
1129 | * ExecAllocTableSlot |
1130 | * |
1131 | * Create a tuple table slot within a tuple table (which is just a List). |
1132 | * -------------------------------- |
1133 | */ |
1134 | TupleTableSlot * |
1135 | ExecAllocTableSlot(List **tupleTable, TupleDesc desc, |
1136 | const TupleTableSlotOps *tts_ops) |
1137 | { |
1138 | TupleTableSlot *slot = MakeTupleTableSlot(desc, tts_ops); |
1139 | |
1140 | *tupleTable = lappend(*tupleTable, slot); |
1141 | |
1142 | return slot; |
1143 | } |
1144 | |
1145 | /* -------------------------------- |
1146 | * ExecResetTupleTable |
1147 | * |
1148 | * This releases any resources (buffer pins, tupdesc refcounts) |
1149 | * held by the tuple table, and optionally releases the memory |
1150 | * occupied by the tuple table data structure. |
1151 | * It is expected that this routine be called by EndPlan(). |
1152 | * -------------------------------- |
1153 | */ |
1154 | void |
1155 | ExecResetTupleTable(List *tupleTable, /* tuple table */ |
1156 | bool shouldFree) /* true if we should free memory */ |
1157 | { |
1158 | ListCell *lc; |
1159 | |
1160 | foreach(lc, tupleTable) |
1161 | { |
1162 | TupleTableSlot *slot = lfirst_node(TupleTableSlot, lc); |
1163 | |
1164 | /* Always release resources and reset the slot to empty */ |
1165 | ExecClearTuple(slot); |
1166 | slot->tts_ops->release(slot); |
1167 | if (slot->tts_tupleDescriptor) |
1168 | { |
1169 | ReleaseTupleDesc(slot->tts_tupleDescriptor); |
1170 | slot->tts_tupleDescriptor = NULL; |
1171 | } |
1172 | |
1173 | /* If shouldFree, release memory occupied by the slot itself */ |
1174 | if (shouldFree) |
1175 | { |
1176 | if (!TTS_FIXED(slot)) |
1177 | { |
1178 | if (slot->tts_values) |
1179 | pfree(slot->tts_values); |
1180 | if (slot->tts_isnull) |
1181 | pfree(slot->tts_isnull); |
1182 | } |
1183 | pfree(slot); |
1184 | } |
1185 | } |
1186 | |
1187 | /* If shouldFree, release the list structure */ |
1188 | if (shouldFree) |
1189 | list_free(tupleTable); |
1190 | } |
1191 | |
1192 | /* -------------------------------- |
1193 | * MakeSingleTupleTableSlot |
1194 | * |
1195 | * This is a convenience routine for operations that need a standalone |
1196 | * TupleTableSlot not gotten from the main executor tuple table. It makes |
1197 | * a single slot of given TupleTableSlotType and initializes it to use the |
1198 | * given tuple descriptor. |
1199 | * -------------------------------- |
1200 | */ |
1201 | TupleTableSlot * |
1202 | MakeSingleTupleTableSlot(TupleDesc tupdesc, |
1203 | const TupleTableSlotOps *tts_ops) |
1204 | { |
1205 | TupleTableSlot *slot = MakeTupleTableSlot(tupdesc, tts_ops); |
1206 | |
1207 | return slot; |
1208 | } |
1209 | |
1210 | /* -------------------------------- |
1211 | * ExecDropSingleTupleTableSlot |
1212 | * |
1213 | * Release a TupleTableSlot made with MakeSingleTupleTableSlot. |
1214 | * DON'T use this on a slot that's part of a tuple table list! |
1215 | * -------------------------------- |
1216 | */ |
1217 | void |
1218 | ExecDropSingleTupleTableSlot(TupleTableSlot *slot) |
1219 | { |
1220 | /* This should match ExecResetTupleTable's processing of one slot */ |
1221 | Assert(IsA(slot, TupleTableSlot)); |
1222 | ExecClearTuple(slot); |
1223 | slot->tts_ops->release(slot); |
1224 | if (slot->tts_tupleDescriptor) |
1225 | ReleaseTupleDesc(slot->tts_tupleDescriptor); |
1226 | if (!TTS_FIXED(slot)) |
1227 | { |
1228 | if (slot->tts_values) |
1229 | pfree(slot->tts_values); |
1230 | if (slot->tts_isnull) |
1231 | pfree(slot->tts_isnull); |
1232 | } |
1233 | pfree(slot); |
1234 | } |
1235 | |
1236 | |
1237 | /* ---------------------------------------------------------------- |
1238 | * tuple table slot accessor functions |
1239 | * ---------------------------------------------------------------- |
1240 | */ |
1241 | |
1242 | /* -------------------------------- |
1243 | * ExecSetSlotDescriptor |
1244 | * |
1245 | * This function is used to set the tuple descriptor associated |
1246 | * with the slot's tuple. The passed descriptor must have lifespan |
1247 | * at least equal to the slot's. If it is a reference-counted descriptor |
1248 | * then the reference count is incremented for as long as the slot holds |
1249 | * a reference. |
1250 | * -------------------------------- |
1251 | */ |
1252 | void |
1253 | ExecSetSlotDescriptor(TupleTableSlot *slot, /* slot to change */ |
1254 | TupleDesc tupdesc) /* new tuple descriptor */ |
1255 | { |
1256 | Assert(!TTS_FIXED(slot)); |
1257 | |
1258 | /* For safety, make sure slot is empty before changing it */ |
1259 | ExecClearTuple(slot); |
1260 | |
1261 | /* |
1262 | * Release any old descriptor. Also release old Datum/isnull arrays if |
1263 | * present (we don't bother to check if they could be re-used). |
1264 | */ |
1265 | if (slot->tts_tupleDescriptor) |
1266 | ReleaseTupleDesc(slot->tts_tupleDescriptor); |
1267 | |
1268 | if (slot->tts_values) |
1269 | pfree(slot->tts_values); |
1270 | if (slot->tts_isnull) |
1271 | pfree(slot->tts_isnull); |
1272 | |
1273 | /* |
1274 | * Install the new descriptor; if it's refcounted, bump its refcount. |
1275 | */ |
1276 | slot->tts_tupleDescriptor = tupdesc; |
1277 | PinTupleDesc(tupdesc); |
1278 | |
1279 | /* |
1280 | * Allocate Datum/isnull arrays of the appropriate size. These must have |
1281 | * the same lifetime as the slot, so allocate in the slot's own context. |
1282 | */ |
1283 | slot->tts_values = (Datum *) |
1284 | MemoryContextAlloc(slot->tts_mcxt, tupdesc->natts * sizeof(Datum)); |
1285 | slot->tts_isnull = (bool *) |
1286 | MemoryContextAlloc(slot->tts_mcxt, tupdesc->natts * sizeof(bool)); |
1287 | } |
1288 | |
1289 | /* -------------------------------- |
1290 | * ExecStoreHeapTuple |
1291 | * |
1292 | * This function is used to store an on-the-fly physical tuple into a specified |
1293 | * slot in the tuple table. |
1294 | * |
1295 | * tuple: tuple to store |
1296 | * slot: TTSOpsHeapTuple type slot to store it in |
1297 | * shouldFree: true if ExecClearTuple should pfree() the tuple |
1298 | * when done with it |
1299 | * |
1300 | * shouldFree is normally set 'true' for tuples constructed on-the-fly. But it |
1301 | * can be 'false' when the referenced tuple is held in a tuple table slot |
1302 | * belonging to a lower-level executor Proc node. In this case the lower-level |
1303 | * slot retains ownership and responsibility for eventually releasing the |
1304 | * tuple. When this method is used, we must be certain that the upper-level |
1305 | * Proc node will lose interest in the tuple sooner than the lower-level one |
1306 | * does! If you're not certain, copy the lower-level tuple with heap_copytuple |
1307 | * and let the upper-level table slot assume ownership of the copy! |
1308 | * |
1309 | * Return value is just the passed-in slot pointer. |
1310 | * |
1311 | * If the target slot is not guaranteed to be TTSOpsHeapTuple type slot, use |
1312 | * the, more expensive, ExecForceStoreHeapTuple(). |
1313 | * -------------------------------- |
1314 | */ |
1315 | TupleTableSlot * |
1316 | ExecStoreHeapTuple(HeapTuple tuple, |
1317 | TupleTableSlot *slot, |
1318 | bool shouldFree) |
1319 | { |
1320 | /* |
1321 | * sanity checks |
1322 | */ |
1323 | Assert(tuple != NULL); |
1324 | Assert(slot != NULL); |
1325 | Assert(slot->tts_tupleDescriptor != NULL); |
1326 | |
1327 | if (unlikely(!TTS_IS_HEAPTUPLE(slot))) |
1328 | elog(ERROR, "trying to store a heap tuple into wrong type of slot" ); |
1329 | tts_heap_store_tuple(slot, tuple, shouldFree); |
1330 | |
1331 | slot->tts_tableOid = tuple->t_tableOid; |
1332 | |
1333 | return slot; |
1334 | } |
1335 | |
1336 | /* -------------------------------- |
1337 | * ExecStoreBufferHeapTuple |
1338 | * |
1339 | * This function is used to store an on-disk physical tuple from a buffer |
1340 | * into a specified slot in the tuple table. |
1341 | * |
1342 | * tuple: tuple to store |
1343 | * slot: TTSOpsBufferHeapTuple type slot to store it in |
1344 | * buffer: disk buffer if tuple is in a disk page, else InvalidBuffer |
1345 | * |
1346 | * The tuple table code acquires a pin on the buffer which is held until the |
1347 | * slot is cleared, so that the tuple won't go away on us. |
1348 | * |
1349 | * Return value is just the passed-in slot pointer. |
1350 | * |
1351 | * If the target slot is not guaranteed to be TTSOpsBufferHeapTuple type slot, |
1352 | * use the, more expensive, ExecForceStoreHeapTuple(). |
1353 | * -------------------------------- |
1354 | */ |
1355 | TupleTableSlot * |
1356 | ExecStoreBufferHeapTuple(HeapTuple tuple, |
1357 | TupleTableSlot *slot, |
1358 | Buffer buffer) |
1359 | { |
1360 | /* |
1361 | * sanity checks |
1362 | */ |
1363 | Assert(tuple != NULL); |
1364 | Assert(slot != NULL); |
1365 | Assert(slot->tts_tupleDescriptor != NULL); |
1366 | Assert(BufferIsValid(buffer)); |
1367 | |
1368 | if (unlikely(!TTS_IS_BUFFERTUPLE(slot))) |
1369 | elog(ERROR, "trying to store an on-disk heap tuple into wrong type of slot" ); |
1370 | tts_buffer_heap_store_tuple(slot, tuple, buffer, false); |
1371 | |
1372 | slot->tts_tableOid = tuple->t_tableOid; |
1373 | |
1374 | return slot; |
1375 | } |
1376 | |
1377 | /* |
1378 | * Like ExecStoreBufferHeapTuple, but transfer an existing pin from the caller |
1379 | * to the slot, i.e. the caller doesn't need to, and may not, release the pin. |
1380 | */ |
1381 | TupleTableSlot * |
1382 | ExecStorePinnedBufferHeapTuple(HeapTuple tuple, |
1383 | TupleTableSlot *slot, |
1384 | Buffer buffer) |
1385 | { |
1386 | /* |
1387 | * sanity checks |
1388 | */ |
1389 | Assert(tuple != NULL); |
1390 | Assert(slot != NULL); |
1391 | Assert(slot->tts_tupleDescriptor != NULL); |
1392 | Assert(BufferIsValid(buffer)); |
1393 | |
1394 | if (unlikely(!TTS_IS_BUFFERTUPLE(slot))) |
1395 | elog(ERROR, "trying to store an on-disk heap tuple into wrong type of slot" ); |
1396 | tts_buffer_heap_store_tuple(slot, tuple, buffer, true); |
1397 | |
1398 | slot->tts_tableOid = tuple->t_tableOid; |
1399 | |
1400 | return slot; |
1401 | } |
1402 | |
1403 | /* |
1404 | * Store a minimal tuple into TTSOpsMinimalTuple type slot. |
1405 | * |
1406 | * If the target slot is not guaranteed to be TTSOpsMinimalTuple type slot, |
1407 | * use the, more expensive, ExecForceStoreMinimalTuple(). |
1408 | */ |
1409 | TupleTableSlot * |
1410 | ExecStoreMinimalTuple(MinimalTuple mtup, |
1411 | TupleTableSlot *slot, |
1412 | bool shouldFree) |
1413 | { |
1414 | /* |
1415 | * sanity checks |
1416 | */ |
1417 | Assert(mtup != NULL); |
1418 | Assert(slot != NULL); |
1419 | Assert(slot->tts_tupleDescriptor != NULL); |
1420 | |
1421 | if (unlikely(!TTS_IS_MINIMALTUPLE(slot))) |
1422 | elog(ERROR, "trying to store a minimal tuple into wrong type of slot" ); |
1423 | tts_minimal_store_tuple(slot, mtup, shouldFree); |
1424 | |
1425 | return slot; |
1426 | } |
1427 | |
1428 | /* |
1429 | * Store a HeapTuple into any kind of slot, performing conversion if |
1430 | * necessary. |
1431 | */ |
1432 | void |
1433 | ExecForceStoreHeapTuple(HeapTuple tuple, |
1434 | TupleTableSlot *slot, |
1435 | bool shouldFree) |
1436 | { |
1437 | if (TTS_IS_HEAPTUPLE(slot)) |
1438 | { |
1439 | ExecStoreHeapTuple(tuple, slot, shouldFree); |
1440 | } |
1441 | else if (TTS_IS_BUFFERTUPLE(slot)) |
1442 | { |
1443 | MemoryContext oldContext; |
1444 | BufferHeapTupleTableSlot *bslot = (BufferHeapTupleTableSlot *) slot; |
1445 | |
1446 | ExecClearTuple(slot); |
1447 | slot->tts_flags |= TTS_FLAG_SHOULDFREE; |
1448 | slot->tts_flags &= ~TTS_FLAG_EMPTY; |
1449 | oldContext = MemoryContextSwitchTo(slot->tts_mcxt); |
1450 | bslot->base.tuple = heap_copytuple(tuple); |
1451 | MemoryContextSwitchTo(oldContext); |
1452 | |
1453 | if (shouldFree) |
1454 | pfree(tuple); |
1455 | } |
1456 | else |
1457 | { |
1458 | ExecClearTuple(slot); |
1459 | heap_deform_tuple(tuple, slot->tts_tupleDescriptor, |
1460 | slot->tts_values, slot->tts_isnull); |
1461 | ExecStoreVirtualTuple(slot); |
1462 | |
1463 | if (shouldFree) |
1464 | { |
1465 | ExecMaterializeSlot(slot); |
1466 | pfree(tuple); |
1467 | } |
1468 | } |
1469 | } |
1470 | |
1471 | /* |
1472 | * Store a MinimalTuple into any kind of slot, performing conversion if |
1473 | * necessary. |
1474 | */ |
1475 | void |
1476 | ExecForceStoreMinimalTuple(MinimalTuple mtup, |
1477 | TupleTableSlot *slot, |
1478 | bool shouldFree) |
1479 | { |
1480 | if (TTS_IS_MINIMALTUPLE(slot)) |
1481 | { |
1482 | tts_minimal_store_tuple(slot, mtup, shouldFree); |
1483 | } |
1484 | else |
1485 | { |
1486 | HeapTupleData htup; |
1487 | |
1488 | ExecClearTuple(slot); |
1489 | |
1490 | htup.t_len = mtup->t_len + MINIMAL_TUPLE_OFFSET; |
1491 | htup.t_data = (HeapTupleHeader) ((char *) mtup - MINIMAL_TUPLE_OFFSET); |
1492 | heap_deform_tuple(&htup, slot->tts_tupleDescriptor, |
1493 | slot->tts_values, slot->tts_isnull); |
1494 | ExecStoreVirtualTuple(slot); |
1495 | |
1496 | if (shouldFree) |
1497 | { |
1498 | ExecMaterializeSlot(slot); |
1499 | pfree(mtup); |
1500 | } |
1501 | } |
1502 | } |
1503 | |
1504 | /* -------------------------------- |
1505 | * ExecStoreVirtualTuple |
1506 | * Mark a slot as containing a virtual tuple. |
1507 | * |
1508 | * The protocol for loading a slot with virtual tuple data is: |
1509 | * * Call ExecClearTuple to mark the slot empty. |
1510 | * * Store data into the Datum/isnull arrays. |
1511 | * * Call ExecStoreVirtualTuple to mark the slot valid. |
1512 | * This is a bit unclean but it avoids one round of data copying. |
1513 | * -------------------------------- |
1514 | */ |
1515 | TupleTableSlot * |
1516 | ExecStoreVirtualTuple(TupleTableSlot *slot) |
1517 | { |
1518 | /* |
1519 | * sanity checks |
1520 | */ |
1521 | Assert(slot != NULL); |
1522 | Assert(slot->tts_tupleDescriptor != NULL); |
1523 | Assert(TTS_EMPTY(slot)); |
1524 | |
1525 | slot->tts_flags &= ~TTS_FLAG_EMPTY; |
1526 | slot->tts_nvalid = slot->tts_tupleDescriptor->natts; |
1527 | |
1528 | return slot; |
1529 | } |
1530 | |
1531 | /* -------------------------------- |
1532 | * ExecStoreAllNullTuple |
1533 | * Set up the slot to contain a null in every column. |
1534 | * |
1535 | * At first glance this might sound just like ExecClearTuple, but it's |
1536 | * entirely different: the slot ends up full, not empty. |
1537 | * -------------------------------- |
1538 | */ |
1539 | TupleTableSlot * |
1540 | ExecStoreAllNullTuple(TupleTableSlot *slot) |
1541 | { |
1542 | /* |
1543 | * sanity checks |
1544 | */ |
1545 | Assert(slot != NULL); |
1546 | Assert(slot->tts_tupleDescriptor != NULL); |
1547 | |
1548 | /* Clear any old contents */ |
1549 | ExecClearTuple(slot); |
1550 | |
1551 | /* |
1552 | * Fill all the columns of the virtual tuple with nulls |
1553 | */ |
1554 | MemSet(slot->tts_values, 0, |
1555 | slot->tts_tupleDescriptor->natts * sizeof(Datum)); |
1556 | memset(slot->tts_isnull, true, |
1557 | slot->tts_tupleDescriptor->natts * sizeof(bool)); |
1558 | |
1559 | return ExecStoreVirtualTuple(slot); |
1560 | } |
1561 | |
1562 | /* |
1563 | * Store a HeapTuple in datum form, into a slot. That always requires |
1564 | * deforming it and storing it in virtual form. |
1565 | * |
1566 | * Until the slot is materialized, the contents of the slot depend on the |
1567 | * datum. |
1568 | */ |
1569 | void |
1570 | ExecStoreHeapTupleDatum(Datum data, TupleTableSlot *slot) |
1571 | { |
1572 | HeapTupleData tuple = {0}; |
1573 | HeapTupleHeader td; |
1574 | |
1575 | td = DatumGetHeapTupleHeader(data); |
1576 | |
1577 | tuple.t_len = HeapTupleHeaderGetDatumLength(td); |
1578 | tuple.t_self = td->t_ctid; |
1579 | tuple.t_data = td; |
1580 | |
1581 | ExecClearTuple(slot); |
1582 | |
1583 | heap_deform_tuple(&tuple, slot->tts_tupleDescriptor, |
1584 | slot->tts_values, slot->tts_isnull); |
1585 | ExecStoreVirtualTuple(slot); |
1586 | } |
1587 | |
1588 | /* |
1589 | * ExecFetchSlotHeapTuple - fetch HeapTuple representing the slot's content |
1590 | * |
1591 | * The returned HeapTuple represents the slot's content as closely as |
1592 | * possible. |
1593 | * |
1594 | * If materialize is true, the contents of the slots will be made independent |
1595 | * from the underlying storage (i.e. all buffer pins are released, memory is |
1596 | * allocated in the slot's context). |
1597 | * |
1598 | * If shouldFree is not-NULL it'll be set to true if the returned tuple has |
1599 | * been allocated in the calling memory context, and must be freed by the |
1600 | * caller (via explicit pfree() or a memory context reset). |
1601 | * |
1602 | * NB: If materialize is true, modifications of the returned tuple are |
1603 | * allowed. But it depends on the type of the slot whether such modifications |
1604 | * will also affect the slot's contents. While that is not the nicest |
1605 | * behaviour, all such modifications are in the process of being removed. |
1606 | */ |
1607 | HeapTuple |
1608 | ExecFetchSlotHeapTuple(TupleTableSlot *slot, bool materialize, bool *shouldFree) |
1609 | { |
1610 | /* |
1611 | * sanity checks |
1612 | */ |
1613 | Assert(slot != NULL); |
1614 | Assert(!TTS_EMPTY(slot)); |
1615 | |
1616 | /* Materialize the tuple so that the slot "owns" it, if requested. */ |
1617 | if (materialize) |
1618 | slot->tts_ops->materialize(slot); |
1619 | |
1620 | if (slot->tts_ops->get_heap_tuple == NULL) |
1621 | { |
1622 | if (shouldFree) |
1623 | *shouldFree = true; |
1624 | return slot->tts_ops->copy_heap_tuple(slot); |
1625 | } |
1626 | else |
1627 | { |
1628 | if (shouldFree) |
1629 | *shouldFree = false; |
1630 | return slot->tts_ops->get_heap_tuple(slot); |
1631 | } |
1632 | } |
1633 | |
1634 | /* -------------------------------- |
1635 | * ExecFetchSlotMinimalTuple |
1636 | * Fetch the slot's minimal physical tuple. |
1637 | * |
1638 | * If the given tuple table slot can hold a minimal tuple, indicated by a |
1639 | * non-NULL get_minimal_tuple callback, the function returns the minimal |
1640 | * tuple returned by that callback. It assumes that the minimal tuple |
1641 | * returned by the callback is "owned" by the slot i.e. the slot is |
1642 | * responsible for freeing the memory consumed by the tuple. Hence it sets |
1643 | * *shouldFree to false, indicating that the caller should not free the |
1644 | * memory consumed by the minimal tuple. In this case the returned minimal |
1645 | * tuple should be considered as read-only. |
1646 | * |
1647 | * If that callback is not supported, it calls copy_minimal_tuple callback |
1648 | * which is expected to return a copy of minimal tuple representing the |
1649 | * contents of the slot. In this case *shouldFree is set to true, |
1650 | * indicating the caller that it should free the memory consumed by the |
1651 | * minimal tuple. In this case the returned minimal tuple may be written |
1652 | * up. |
1653 | * -------------------------------- |
1654 | */ |
1655 | MinimalTuple |
1656 | ExecFetchSlotMinimalTuple(TupleTableSlot *slot, |
1657 | bool *shouldFree) |
1658 | { |
1659 | /* |
1660 | * sanity checks |
1661 | */ |
1662 | Assert(slot != NULL); |
1663 | Assert(!TTS_EMPTY(slot)); |
1664 | |
1665 | if (slot->tts_ops->get_minimal_tuple) |
1666 | { |
1667 | if (shouldFree) |
1668 | *shouldFree = false; |
1669 | return slot->tts_ops->get_minimal_tuple(slot); |
1670 | } |
1671 | else |
1672 | { |
1673 | if (shouldFree) |
1674 | *shouldFree = true; |
1675 | return slot->tts_ops->copy_minimal_tuple(slot); |
1676 | } |
1677 | } |
1678 | |
1679 | /* -------------------------------- |
1680 | * ExecFetchSlotHeapTupleDatum |
1681 | * Fetch the slot's tuple as a composite-type Datum. |
1682 | * |
1683 | * The result is always freshly palloc'd in the caller's memory context. |
1684 | * -------------------------------- |
1685 | */ |
1686 | Datum |
1687 | ExecFetchSlotHeapTupleDatum(TupleTableSlot *slot) |
1688 | { |
1689 | HeapTuple tup; |
1690 | TupleDesc tupdesc; |
1691 | bool shouldFree; |
1692 | Datum ret; |
1693 | |
1694 | /* Fetch slot's contents in regular-physical-tuple form */ |
1695 | tup = ExecFetchSlotHeapTuple(slot, false, &shouldFree); |
1696 | tupdesc = slot->tts_tupleDescriptor; |
1697 | |
1698 | /* Convert to Datum form */ |
1699 | ret = heap_copy_tuple_as_datum(tup, tupdesc); |
1700 | |
1701 | if (shouldFree) |
1702 | pfree(tup); |
1703 | |
1704 | return ret; |
1705 | } |
1706 | |
1707 | /* ---------------------------------------------------------------- |
1708 | * convenience initialization routines |
1709 | * ---------------------------------------------------------------- |
1710 | */ |
1711 | |
1712 | /* ---------------- |
1713 | * ExecInitResultTypeTL |
1714 | * |
1715 | * Initialize result type, using the plan node's targetlist. |
1716 | * ---------------- |
1717 | */ |
1718 | void |
1719 | ExecInitResultTypeTL(PlanState *planstate) |
1720 | { |
1721 | TupleDesc tupDesc = ExecTypeFromTL(planstate->plan->targetlist); |
1722 | |
1723 | planstate->ps_ResultTupleDesc = tupDesc; |
1724 | } |
1725 | |
1726 | /* -------------------------------- |
1727 | * ExecInit{Result,Scan,Extra}TupleSlot[TL] |
1728 | * |
1729 | * These are convenience routines to initialize the specified slot |
1730 | * in nodes inheriting the appropriate state. ExecInitExtraTupleSlot |
1731 | * is used for initializing special-purpose slots. |
1732 | * -------------------------------- |
1733 | */ |
1734 | |
1735 | /* ---------------- |
1736 | * ExecInitResultTupleSlotTL |
1737 | * |
1738 | * Initialize result tuple slot, using the tuple descriptor previously |
1739 | * computed with ExecInitResultTypeTL(). |
1740 | * ---------------- |
1741 | */ |
1742 | void |
1743 | ExecInitResultSlot(PlanState *planstate, const TupleTableSlotOps *tts_ops) |
1744 | { |
1745 | TupleTableSlot *slot; |
1746 | |
1747 | slot = ExecAllocTableSlot(&planstate->state->es_tupleTable, |
1748 | planstate->ps_ResultTupleDesc, tts_ops); |
1749 | planstate->ps_ResultTupleSlot = slot; |
1750 | |
1751 | planstate->resultopsfixed = planstate->ps_ResultTupleDesc != NULL; |
1752 | planstate->resultops = tts_ops; |
1753 | planstate->resultopsset = true; |
1754 | } |
1755 | |
1756 | /* ---------------- |
1757 | * ExecInitResultTupleSlotTL |
1758 | * |
1759 | * Initialize result tuple slot, using the plan node's targetlist. |
1760 | * ---------------- |
1761 | */ |
1762 | void |
1763 | ExecInitResultTupleSlotTL(PlanState *planstate, |
1764 | const TupleTableSlotOps *tts_ops) |
1765 | { |
1766 | ExecInitResultTypeTL(planstate); |
1767 | ExecInitResultSlot(planstate, tts_ops); |
1768 | } |
1769 | |
1770 | /* ---------------- |
1771 | * ExecInitScanTupleSlot |
1772 | * ---------------- |
1773 | */ |
1774 | void |
1775 | ExecInitScanTupleSlot(EState *estate, ScanState *scanstate, |
1776 | TupleDesc tupledesc, const TupleTableSlotOps *tts_ops) |
1777 | { |
1778 | scanstate->ss_ScanTupleSlot = ExecAllocTableSlot(&estate->es_tupleTable, |
1779 | tupledesc, tts_ops); |
1780 | scanstate->ps.scandesc = tupledesc; |
1781 | scanstate->ps.scanopsfixed = tupledesc != NULL; |
1782 | scanstate->ps.scanops = tts_ops; |
1783 | scanstate->ps.scanopsset = true; |
1784 | } |
1785 | |
1786 | /* ---------------- |
1787 | * ExecInitExtraTupleSlot |
1788 | * |
1789 | * Return a newly created slot. If tupledesc is non-NULL the slot will have |
1790 | * that as its fixed tupledesc. Otherwise the caller needs to use |
1791 | * ExecSetSlotDescriptor() to set the descriptor before use. |
1792 | * ---------------- |
1793 | */ |
1794 | TupleTableSlot * |
1795 | (EState *estate, |
1796 | TupleDesc tupledesc, |
1797 | const TupleTableSlotOps *tts_ops) |
1798 | { |
1799 | return ExecAllocTableSlot(&estate->es_tupleTable, tupledesc, tts_ops); |
1800 | } |
1801 | |
1802 | /* ---------------- |
1803 | * ExecInitNullTupleSlot |
1804 | * |
1805 | * Build a slot containing an all-nulls tuple of the given type. |
1806 | * This is used as a substitute for an input tuple when performing an |
1807 | * outer join. |
1808 | * ---------------- |
1809 | */ |
1810 | TupleTableSlot * |
1811 | ExecInitNullTupleSlot(EState *estate, TupleDesc tupType, |
1812 | const TupleTableSlotOps *tts_ops) |
1813 | { |
1814 | TupleTableSlot *slot = ExecInitExtraTupleSlot(estate, tupType, tts_ops); |
1815 | |
1816 | return ExecStoreAllNullTuple(slot); |
1817 | } |
1818 | |
1819 | /* --------------------------------------------------------------- |
1820 | * Routines for setting/accessing attributes in a slot. |
1821 | * --------------------------------------------------------------- |
1822 | */ |
1823 | |
1824 | /* |
1825 | * Fill in missing values for a TupleTableSlot. |
1826 | * |
1827 | * This is only exposed because it's needed for JIT compiled tuple |
1828 | * deforming. That exception aside, there should be no callers outside of this |
1829 | * file. |
1830 | */ |
1831 | void |
1832 | slot_getmissingattrs(TupleTableSlot *slot, int startAttNum, int lastAttNum) |
1833 | { |
1834 | AttrMissing *attrmiss = NULL; |
1835 | |
1836 | if (slot->tts_tupleDescriptor->constr) |
1837 | attrmiss = slot->tts_tupleDescriptor->constr->missing; |
1838 | |
1839 | if (!attrmiss) |
1840 | { |
1841 | /* no missing values array at all, so just fill everything in as NULL */ |
1842 | memset(slot->tts_values + startAttNum, 0, |
1843 | (lastAttNum - startAttNum) * sizeof(Datum)); |
1844 | memset(slot->tts_isnull + startAttNum, 1, |
1845 | (lastAttNum - startAttNum) * sizeof(bool)); |
1846 | } |
1847 | else |
1848 | { |
1849 | int missattnum; |
1850 | |
1851 | /* if there is a missing values array we must process them one by one */ |
1852 | for (missattnum = startAttNum; |
1853 | missattnum < lastAttNum; |
1854 | missattnum++) |
1855 | { |
1856 | slot->tts_values[missattnum] = attrmiss[missattnum].am_value; |
1857 | slot->tts_isnull[missattnum] = !attrmiss[missattnum].am_present; |
1858 | } |
1859 | |
1860 | } |
1861 | } |
1862 | |
1863 | /* |
1864 | * slot_getsomeattrs_int - workhorse for slot_getsomeattrs() |
1865 | */ |
1866 | void |
1867 | slot_getsomeattrs_int(TupleTableSlot *slot, int attnum) |
1868 | { |
1869 | /* Check for caller errors */ |
1870 | Assert(slot->tts_nvalid < attnum); /* checked in slot_getsomeattrs */ |
1871 | Assert(attnum > 0); |
1872 | |
1873 | if (unlikely(attnum > slot->tts_tupleDescriptor->natts)) |
1874 | elog(ERROR, "invalid attribute number %d" , attnum); |
1875 | |
1876 | /* Fetch as many attributes as possible from the underlying tuple. */ |
1877 | slot->tts_ops->getsomeattrs(slot, attnum); |
1878 | |
1879 | /* |
1880 | * If the underlying tuple doesn't have enough attributes, tuple |
1881 | * descriptor must have the missing attributes. |
1882 | */ |
1883 | if (unlikely(slot->tts_nvalid < attnum)) |
1884 | { |
1885 | slot_getmissingattrs(slot, slot->tts_nvalid, attnum); |
1886 | slot->tts_nvalid = attnum; |
1887 | } |
1888 | } |
1889 | |
1890 | /* ---------------------------------------------------------------- |
1891 | * ExecTypeFromTL |
1892 | * |
1893 | * Generate a tuple descriptor for the result tuple of a targetlist. |
1894 | * (A parse/plan tlist must be passed, not an ExprState tlist.) |
1895 | * Note that resjunk columns, if any, are included in the result. |
1896 | * |
1897 | * Currently there are about 4 different places where we create |
1898 | * TupleDescriptors. They should all be merged, or perhaps |
1899 | * be rewritten to call BuildDesc(). |
1900 | * ---------------------------------------------------------------- |
1901 | */ |
1902 | TupleDesc |
1903 | ExecTypeFromTL(List *targetList) |
1904 | { |
1905 | return ExecTypeFromTLInternal(targetList, false); |
1906 | } |
1907 | |
1908 | /* ---------------------------------------------------------------- |
1909 | * ExecCleanTypeFromTL |
1910 | * |
1911 | * Same as above, but resjunk columns are omitted from the result. |
1912 | * ---------------------------------------------------------------- |
1913 | */ |
1914 | TupleDesc |
1915 | ExecCleanTypeFromTL(List *targetList) |
1916 | { |
1917 | return ExecTypeFromTLInternal(targetList, true); |
1918 | } |
1919 | |
1920 | static TupleDesc |
1921 | ExecTypeFromTLInternal(List *targetList, bool skipjunk) |
1922 | { |
1923 | TupleDesc typeInfo; |
1924 | ListCell *l; |
1925 | int len; |
1926 | int cur_resno = 1; |
1927 | |
1928 | if (skipjunk) |
1929 | len = ExecCleanTargetListLength(targetList); |
1930 | else |
1931 | len = ExecTargetListLength(targetList); |
1932 | typeInfo = CreateTemplateTupleDesc(len); |
1933 | |
1934 | foreach(l, targetList) |
1935 | { |
1936 | TargetEntry *tle = lfirst(l); |
1937 | |
1938 | if (skipjunk && tle->resjunk) |
1939 | continue; |
1940 | TupleDescInitEntry(typeInfo, |
1941 | cur_resno, |
1942 | tle->resname, |
1943 | exprType((Node *) tle->expr), |
1944 | exprTypmod((Node *) tle->expr), |
1945 | 0); |
1946 | TupleDescInitEntryCollation(typeInfo, |
1947 | cur_resno, |
1948 | exprCollation((Node *) tle->expr)); |
1949 | cur_resno++; |
1950 | } |
1951 | |
1952 | return typeInfo; |
1953 | } |
1954 | |
1955 | /* |
1956 | * ExecTypeFromExprList - build a tuple descriptor from a list of Exprs |
1957 | * |
1958 | * This is roughly like ExecTypeFromTL, but we work from bare expressions |
1959 | * not TargetEntrys. No names are attached to the tupledesc's columns. |
1960 | */ |
1961 | TupleDesc |
1962 | ExecTypeFromExprList(List *exprList) |
1963 | { |
1964 | TupleDesc typeInfo; |
1965 | ListCell *lc; |
1966 | int cur_resno = 1; |
1967 | |
1968 | typeInfo = CreateTemplateTupleDesc(list_length(exprList)); |
1969 | |
1970 | foreach(lc, exprList) |
1971 | { |
1972 | Node *e = lfirst(lc); |
1973 | |
1974 | TupleDescInitEntry(typeInfo, |
1975 | cur_resno, |
1976 | NULL, |
1977 | exprType(e), |
1978 | exprTypmod(e), |
1979 | 0); |
1980 | TupleDescInitEntryCollation(typeInfo, |
1981 | cur_resno, |
1982 | exprCollation(e)); |
1983 | cur_resno++; |
1984 | } |
1985 | |
1986 | return typeInfo; |
1987 | } |
1988 | |
1989 | /* |
1990 | * ExecTypeSetColNames - set column names in a TupleDesc |
1991 | * |
1992 | * Column names must be provided as an alias list (list of String nodes). |
1993 | * |
1994 | * For some callers, the supplied tupdesc has a named rowtype (not RECORD) |
1995 | * and it is moderately likely that the alias list matches the column names |
1996 | * already present in the tupdesc. If we do change any column names then |
1997 | * we must reset the tupdesc's type to anonymous RECORD; but we avoid doing |
1998 | * so if no names change. |
1999 | */ |
2000 | void |
2001 | ExecTypeSetColNames(TupleDesc typeInfo, List *namesList) |
2002 | { |
2003 | bool modified = false; |
2004 | int colno = 0; |
2005 | ListCell *lc; |
2006 | |
2007 | foreach(lc, namesList) |
2008 | { |
2009 | char *cname = strVal(lfirst(lc)); |
2010 | Form_pg_attribute attr; |
2011 | |
2012 | /* Guard against too-long names list */ |
2013 | if (colno >= typeInfo->natts) |
2014 | break; |
2015 | attr = TupleDescAttr(typeInfo, colno); |
2016 | colno++; |
2017 | |
2018 | /* Ignore empty aliases (these must be for dropped columns) */ |
2019 | if (cname[0] == '\0') |
2020 | continue; |
2021 | |
2022 | /* Change tupdesc only if alias is actually different */ |
2023 | if (strcmp(cname, NameStr(attr->attname)) != 0) |
2024 | { |
2025 | namestrcpy(&(attr->attname), cname); |
2026 | modified = true; |
2027 | } |
2028 | } |
2029 | |
2030 | /* If we modified the tupdesc, it's now a new record type */ |
2031 | if (modified) |
2032 | { |
2033 | typeInfo->tdtypeid = RECORDOID; |
2034 | typeInfo->tdtypmod = -1; |
2035 | } |
2036 | } |
2037 | |
2038 | /* |
2039 | * BlessTupleDesc - make a completed tuple descriptor useful for SRFs |
2040 | * |
2041 | * Rowtype Datums returned by a function must contain valid type information. |
2042 | * This happens "for free" if the tupdesc came from a relcache entry, but |
2043 | * not if we have manufactured a tupdesc for a transient RECORD datatype. |
2044 | * In that case we have to notify typcache.c of the existence of the type. |
2045 | */ |
2046 | TupleDesc |
2047 | BlessTupleDesc(TupleDesc tupdesc) |
2048 | { |
2049 | if (tupdesc->tdtypeid == RECORDOID && |
2050 | tupdesc->tdtypmod < 0) |
2051 | assign_record_type_typmod(tupdesc); |
2052 | |
2053 | return tupdesc; /* just for notational convenience */ |
2054 | } |
2055 | |
2056 | /* |
2057 | * TupleDescGetAttInMetadata - Build an AttInMetadata structure based on the |
2058 | * supplied TupleDesc. AttInMetadata can be used in conjunction with C strings |
2059 | * to produce a properly formed tuple. |
2060 | */ |
2061 | AttInMetadata * |
2062 | TupleDescGetAttInMetadata(TupleDesc tupdesc) |
2063 | { |
2064 | int natts = tupdesc->natts; |
2065 | int i; |
2066 | Oid atttypeid; |
2067 | Oid attinfuncid; |
2068 | FmgrInfo *attinfuncinfo; |
2069 | Oid *attioparams; |
2070 | int32 *atttypmods; |
2071 | AttInMetadata *attinmeta; |
2072 | |
2073 | attinmeta = (AttInMetadata *) palloc(sizeof(AttInMetadata)); |
2074 | |
2075 | /* "Bless" the tupledesc so that we can make rowtype datums with it */ |
2076 | attinmeta->tupdesc = BlessTupleDesc(tupdesc); |
2077 | |
2078 | /* |
2079 | * Gather info needed later to call the "in" function for each attribute |
2080 | */ |
2081 | attinfuncinfo = (FmgrInfo *) palloc0(natts * sizeof(FmgrInfo)); |
2082 | attioparams = (Oid *) palloc0(natts * sizeof(Oid)); |
2083 | atttypmods = (int32 *) palloc0(natts * sizeof(int32)); |
2084 | |
2085 | for (i = 0; i < natts; i++) |
2086 | { |
2087 | Form_pg_attribute att = TupleDescAttr(tupdesc, i); |
2088 | |
2089 | /* Ignore dropped attributes */ |
2090 | if (!att->attisdropped) |
2091 | { |
2092 | atttypeid = att->atttypid; |
2093 | getTypeInputInfo(atttypeid, &attinfuncid, &attioparams[i]); |
2094 | fmgr_info(attinfuncid, &attinfuncinfo[i]); |
2095 | atttypmods[i] = att->atttypmod; |
2096 | } |
2097 | } |
2098 | attinmeta->attinfuncs = attinfuncinfo; |
2099 | attinmeta->attioparams = attioparams; |
2100 | attinmeta->atttypmods = atttypmods; |
2101 | |
2102 | return attinmeta; |
2103 | } |
2104 | |
2105 | /* |
2106 | * BuildTupleFromCStrings - build a HeapTuple given user data in C string form. |
2107 | * values is an array of C strings, one for each attribute of the return tuple. |
2108 | * A NULL string pointer indicates we want to create a NULL field. |
2109 | */ |
2110 | HeapTuple |
2111 | BuildTupleFromCStrings(AttInMetadata *attinmeta, char **values) |
2112 | { |
2113 | TupleDesc tupdesc = attinmeta->tupdesc; |
2114 | int natts = tupdesc->natts; |
2115 | Datum *dvalues; |
2116 | bool *nulls; |
2117 | int i; |
2118 | HeapTuple tuple; |
2119 | |
2120 | dvalues = (Datum *) palloc(natts * sizeof(Datum)); |
2121 | nulls = (bool *) palloc(natts * sizeof(bool)); |
2122 | |
2123 | /* |
2124 | * Call the "in" function for each non-dropped attribute, even for nulls, |
2125 | * to support domains. |
2126 | */ |
2127 | for (i = 0; i < natts; i++) |
2128 | { |
2129 | if (!TupleDescAttr(tupdesc, i)->attisdropped) |
2130 | { |
2131 | /* Non-dropped attributes */ |
2132 | dvalues[i] = InputFunctionCall(&attinmeta->attinfuncs[i], |
2133 | values[i], |
2134 | attinmeta->attioparams[i], |
2135 | attinmeta->atttypmods[i]); |
2136 | if (values[i] != NULL) |
2137 | nulls[i] = false; |
2138 | else |
2139 | nulls[i] = true; |
2140 | } |
2141 | else |
2142 | { |
2143 | /* Handle dropped attributes by setting to NULL */ |
2144 | dvalues[i] = (Datum) 0; |
2145 | nulls[i] = true; |
2146 | } |
2147 | } |
2148 | |
2149 | /* |
2150 | * Form a tuple |
2151 | */ |
2152 | tuple = heap_form_tuple(tupdesc, dvalues, nulls); |
2153 | |
2154 | /* |
2155 | * Release locally palloc'd space. XXX would probably be good to pfree |
2156 | * values of pass-by-reference datums, as well. |
2157 | */ |
2158 | pfree(dvalues); |
2159 | pfree(nulls); |
2160 | |
2161 | return tuple; |
2162 | } |
2163 | |
2164 | /* |
2165 | * HeapTupleHeaderGetDatum - convert a HeapTupleHeader pointer to a Datum. |
2166 | * |
2167 | * This must *not* get applied to an on-disk tuple; the tuple should be |
2168 | * freshly made by heap_form_tuple or some wrapper routine for it (such as |
2169 | * BuildTupleFromCStrings). Be sure also that the tupledesc used to build |
2170 | * the tuple has a properly "blessed" rowtype. |
2171 | * |
2172 | * Formerly this was a macro equivalent to PointerGetDatum, relying on the |
2173 | * fact that heap_form_tuple fills in the appropriate tuple header fields |
2174 | * for a composite Datum. However, we now require that composite Datums not |
2175 | * contain any external TOAST pointers. We do not want heap_form_tuple itself |
2176 | * to enforce that; more specifically, the rule applies only to actual Datums |
2177 | * and not to HeapTuple structures. Therefore, HeapTupleHeaderGetDatum is |
2178 | * now a function that detects whether there are externally-toasted fields |
2179 | * and constructs a new tuple with inlined fields if so. We still need |
2180 | * heap_form_tuple to insert the Datum header fields, because otherwise this |
2181 | * code would have no way to obtain a tupledesc for the tuple. |
2182 | * |
2183 | * Note that if we do build a new tuple, it's palloc'd in the current |
2184 | * memory context. Beware of code that changes context between the initial |
2185 | * heap_form_tuple/etc call and calling HeapTuple(Header)GetDatum. |
2186 | * |
2187 | * For performance-critical callers, it could be worthwhile to take extra |
2188 | * steps to ensure that there aren't TOAST pointers in the output of |
2189 | * heap_form_tuple to begin with. It's likely however that the costs of the |
2190 | * typcache lookup and tuple disassembly/reassembly are swamped by TOAST |
2191 | * dereference costs, so that the benefits of such extra effort would be |
2192 | * minimal. |
2193 | * |
2194 | * XXX it would likely be better to create wrapper functions that produce |
2195 | * a composite Datum from the field values in one step. However, there's |
2196 | * enough code using the existing APIs that we couldn't get rid of this |
2197 | * hack anytime soon. |
2198 | */ |
2199 | Datum |
2200 | (HeapTupleHeader tuple) |
2201 | { |
2202 | Datum result; |
2203 | TupleDesc tupDesc; |
2204 | |
2205 | /* No work if there are no external TOAST pointers in the tuple */ |
2206 | if (!HeapTupleHeaderHasExternal(tuple)) |
2207 | return PointerGetDatum(tuple); |
2208 | |
2209 | /* Use the type data saved by heap_form_tuple to look up the rowtype */ |
2210 | tupDesc = lookup_rowtype_tupdesc(HeapTupleHeaderGetTypeId(tuple), |
2211 | HeapTupleHeaderGetTypMod(tuple)); |
2212 | |
2213 | /* And do the flattening */ |
2214 | result = toast_flatten_tuple_to_datum(tuple, |
2215 | HeapTupleHeaderGetDatumLength(tuple), |
2216 | tupDesc); |
2217 | |
2218 | ReleaseTupleDesc(tupDesc); |
2219 | |
2220 | return result; |
2221 | } |
2222 | |
2223 | |
2224 | /* |
2225 | * Functions for sending tuples to the frontend (or other specified destination) |
2226 | * as though it is a SELECT result. These are used by utility commands that |
2227 | * need to project directly to the destination and don't need or want full |
2228 | * table function capability. Currently used by EXPLAIN and SHOW ALL. |
2229 | */ |
2230 | TupOutputState * |
2231 | begin_tup_output_tupdesc(DestReceiver *dest, |
2232 | TupleDesc tupdesc, |
2233 | const TupleTableSlotOps *tts_ops) |
2234 | { |
2235 | TupOutputState *tstate; |
2236 | |
2237 | tstate = (TupOutputState *) palloc(sizeof(TupOutputState)); |
2238 | |
2239 | tstate->slot = MakeSingleTupleTableSlot(tupdesc, tts_ops); |
2240 | tstate->dest = dest; |
2241 | |
2242 | tstate->dest->rStartup(tstate->dest, (int) CMD_SELECT, tupdesc); |
2243 | |
2244 | return tstate; |
2245 | } |
2246 | |
2247 | /* |
2248 | * write a single tuple |
2249 | */ |
2250 | void |
2251 | do_tup_output(TupOutputState *tstate, Datum *values, bool *isnull) |
2252 | { |
2253 | TupleTableSlot *slot = tstate->slot; |
2254 | int natts = slot->tts_tupleDescriptor->natts; |
2255 | |
2256 | /* make sure the slot is clear */ |
2257 | ExecClearTuple(slot); |
2258 | |
2259 | /* insert data */ |
2260 | memcpy(slot->tts_values, values, natts * sizeof(Datum)); |
2261 | memcpy(slot->tts_isnull, isnull, natts * sizeof(bool)); |
2262 | |
2263 | /* mark slot as containing a virtual tuple */ |
2264 | ExecStoreVirtualTuple(slot); |
2265 | |
2266 | /* send the tuple to the receiver */ |
2267 | (void) tstate->dest->receiveSlot(slot, tstate->dest); |
2268 | |
2269 | /* clean up */ |
2270 | ExecClearTuple(slot); |
2271 | } |
2272 | |
2273 | /* |
2274 | * write a chunk of text, breaking at newline characters |
2275 | * |
2276 | * Should only be used with a single-TEXT-attribute tupdesc. |
2277 | */ |
2278 | void |
2279 | do_text_output_multiline(TupOutputState *tstate, const char *txt) |
2280 | { |
2281 | Datum values[1]; |
2282 | bool isnull[1] = {false}; |
2283 | |
2284 | while (*txt) |
2285 | { |
2286 | const char *eol; |
2287 | int len; |
2288 | |
2289 | eol = strchr(txt, '\n'); |
2290 | if (eol) |
2291 | { |
2292 | len = eol - txt; |
2293 | eol++; |
2294 | } |
2295 | else |
2296 | { |
2297 | len = strlen(txt); |
2298 | eol = txt + len; |
2299 | } |
2300 | |
2301 | values[0] = PointerGetDatum(cstring_to_text_with_len(txt, len)); |
2302 | do_tup_output(tstate, values, isnull); |
2303 | pfree(DatumGetPointer(values[0])); |
2304 | txt = eol; |
2305 | } |
2306 | } |
2307 | |
2308 | void |
2309 | end_tup_output(TupOutputState *tstate) |
2310 | { |
2311 | tstate->dest->rShutdown(tstate->dest); |
2312 | /* note that destroying the dest is not ours to do */ |
2313 | ExecDropSingleTupleTableSlot(tstate->slot); |
2314 | pfree(tstate); |
2315 | } |
2316 | |