PostgreSQL Source Code git master
tuplestore.c File Reference
#include "postgres.h"
#include <limits.h>
#include "access/htup_details.h"
#include "commands/tablespace.h"
#include "executor/executor.h"
#include "miscadmin.h"
#include "storage/buffile.h"
#include "utils/memutils.h"
#include "utils/resowner.h"
Include dependency graph for tuplestore.c:

Go to the source code of this file.

Data Structures

struct  TSReadPointer
 
struct  Tuplestorestate
 

Macros

#define COPYTUP(state, tup)   ((*(state)->copytup) (state, tup))
 
#define WRITETUP(state, tup)   ((*(state)->writetup) (state, tup))
 
#define READTUP(state, len)   ((*(state)->readtup) (state, len))
 
#define LACKMEM(state)   ((state)->availMem < 0)
 
#define USEMEM(state, amt)   ((state)->availMem -= (amt))
 
#define FREEMEM(state, amt)   ((state)->availMem += (amt))
 

Enumerations

enum  TupStoreStatus { TSS_INMEM , TSS_WRITEFILE , TSS_READFILE }
 

Functions

static Tuplestorestatetuplestore_begin_common (int eflags, bool interXact, int maxKBytes)
 
static void tuplestore_puttuple_common (Tuplestorestate *state, void *tuple)
 
static void dumptuples (Tuplestorestate *state)
 
static void tuplestore_updatemax (Tuplestorestate *state)
 
static unsigned int getlen (Tuplestorestate *state, bool eofOK)
 
static void * copytup_heap (Tuplestorestate *state, void *tup)
 
static void writetup_heap (Tuplestorestate *state, void *tup)
 
static void * readtup_heap (Tuplestorestate *state, unsigned int len)
 
Tuplestorestatetuplestore_begin_heap (bool randomAccess, bool interXact, int maxKBytes)
 
void tuplestore_set_eflags (Tuplestorestate *state, int eflags)
 
int tuplestore_alloc_read_pointer (Tuplestorestate *state, int eflags)
 
void tuplestore_clear (Tuplestorestate *state)
 
void tuplestore_end (Tuplestorestate *state)
 
void tuplestore_select_read_pointer (Tuplestorestate *state, int ptr)
 
int64 tuplestore_tuple_count (Tuplestorestate *state)
 
bool tuplestore_ateof (Tuplestorestate *state)
 
static bool grow_memtuples (Tuplestorestate *state)
 
void tuplestore_puttupleslot (Tuplestorestate *state, TupleTableSlot *slot)
 
void tuplestore_puttuple (Tuplestorestate *state, HeapTuple tuple)
 
void tuplestore_putvalues (Tuplestorestate *state, TupleDesc tdesc, const Datum *values, const bool *isnull)
 
static void * tuplestore_gettuple (Tuplestorestate *state, bool forward, bool *should_free)
 
bool tuplestore_gettupleslot (Tuplestorestate *state, bool forward, bool copy, TupleTableSlot *slot)
 
bool tuplestore_advance (Tuplestorestate *state, bool forward)
 
bool tuplestore_skiptuples (Tuplestorestate *state, int64 ntuples, bool forward)
 
void tuplestore_rescan (Tuplestorestate *state)
 
void tuplestore_copy_read_pointer (Tuplestorestate *state, int srcptr, int destptr)
 
void tuplestore_trim (Tuplestorestate *state)
 
void tuplestore_get_stats (Tuplestorestate *state, char **max_storage_type, int64 *max_space)
 
bool tuplestore_in_memory (Tuplestorestate *state)
 

Macro Definition Documentation

◆ COPYTUP

#define COPYTUP (   state,
  tup 
)    ((*(state)->copytup) (state, tup))

Definition at line 185 of file tuplestore.c.

◆ FREEMEM

#define FREEMEM (   state,
  amt 
)    ((state)->availMem += (amt))

Definition at line 190 of file tuplestore.c.

◆ LACKMEM

#define LACKMEM (   state)    ((state)->availMem < 0)

Definition at line 188 of file tuplestore.c.

◆ READTUP

#define READTUP (   state,
  len 
)    ((*(state)->readtup) (state, len))

Definition at line 187 of file tuplestore.c.

◆ USEMEM

#define USEMEM (   state,
  amt 
)    ((state)->availMem -= (amt))

Definition at line 189 of file tuplestore.c.

◆ WRITETUP

#define WRITETUP (   state,
  tup 
)    ((*(state)->writetup) (state, tup))

Definition at line 186 of file tuplestore.c.

Enumeration Type Documentation

◆ TupStoreStatus

Enumerator
TSS_INMEM 
TSS_WRITEFILE 
TSS_READFILE 

Definition at line 72 of file tuplestore.c.

73{
74 TSS_INMEM, /* Tuples still fit in memory */
75 TSS_WRITEFILE, /* Writing to temp file */
76 TSS_READFILE, /* Reading from temp file */
TupStoreStatus
Definition: tuplestore.c:73
@ TSS_READFILE
Definition: tuplestore.c:76
@ TSS_INMEM
Definition: tuplestore.c:74
@ TSS_WRITEFILE
Definition: tuplestore.c:75

Function Documentation

◆ copytup_heap()

static void * copytup_heap ( Tuplestorestate state,
void *  tup 
)
static

Definition at line 1589 of file tuplestore.c.

1590{
1591 MinimalTuple tuple;
1592
1595 return tuple;
1596}
MinimalTuple minimal_tuple_from_heap_tuple(HeapTuple htup)
Definition: heaptuple.c:1577
Size GetMemoryChunkSpace(void *pointer)
Definition: mcxt.c:721
Definition: regguts.h:323
#define USEMEM(state, amt)
Definition: tuplestore.c:189

References GetMemoryChunkSpace(), minimal_tuple_from_heap_tuple(), and USEMEM.

Referenced by tuplestore_begin_heap().

◆ dumptuples()

static void dumptuples ( Tuplestorestate state)
static

Definition at line 1258 of file tuplestore.c.

1259{
1260 int i;
1261
1262 for (i = state->memtupdeleted;; i++)
1263 {
1264 TSReadPointer *readptr = state->readptrs;
1265 int j;
1266
1267 for (j = 0; j < state->readptrcount; readptr++, j++)
1268 {
1269 if (i == readptr->current && !readptr->eof_reached)
1270 BufFileTell(state->myfile,
1271 &readptr->file, &readptr->offset);
1272 }
1273 if (i >= state->memtupcount)
1274 break;
1275 WRITETUP(state, state->memtuples[i]);
1276 }
1277 state->memtupdeleted = 0;
1278 state->memtupcount = 0;
1279}
void BufFileTell(BufFile *file, int *fileno, off_t *offset)
Definition: buffile.c:833
int j
Definition: isn.c:73
int i
Definition: isn.c:72
bool eof_reached
Definition: tuplestore.c:94
off_t offset
Definition: tuplestore.c:97
#define WRITETUP(state, tup)
Definition: tuplestore.c:186

References BufFileTell(), TSReadPointer::current, TSReadPointer::eof_reached, TSReadPointer::file, i, j, TSReadPointer::offset, and WRITETUP.

Referenced by tuplestore_puttuple_common().

◆ getlen()

static unsigned int getlen ( Tuplestorestate state,
bool  eofOK 
)
static

Definition at line 1565 of file tuplestore.c.

1566{
1567 unsigned int len;
1568 size_t nbytes;
1569
1570 nbytes = BufFileReadMaybeEOF(state->myfile, &len, sizeof(len), eofOK);
1571 if (nbytes == 0)
1572 return 0;
1573 else
1574 return len;
1575}
size_t BufFileReadMaybeEOF(BufFile *file, void *ptr, size_t size, bool eofOK)
Definition: buffile.c:664
const void size_t len

References BufFileReadMaybeEOF(), and len.

Referenced by tuplestore_gettuple().

◆ grow_memtuples()

static bool grow_memtuples ( Tuplestorestate state)
static

Definition at line 612 of file tuplestore.c.

613{
614 int newmemtupsize;
615 int memtupsize = state->memtupsize;
616 int64 memNowUsed = state->allowedMem - state->availMem;
617
618 /* Forget it if we've already maxed out memtuples, per comment above */
619 if (!state->growmemtuples)
620 return false;
621
622 /* Select new value of memtupsize */
623 if (memNowUsed <= state->availMem)
624 {
625 /*
626 * We've used no more than half of allowedMem; double our usage,
627 * clamping at INT_MAX tuples.
628 */
629 if (memtupsize < INT_MAX / 2)
630 newmemtupsize = memtupsize * 2;
631 else
632 {
633 newmemtupsize = INT_MAX;
634 state->growmemtuples = false;
635 }
636 }
637 else
638 {
639 /*
640 * This will be the last increment of memtupsize. Abandon doubling
641 * strategy and instead increase as much as we safely can.
642 *
643 * To stay within allowedMem, we can't increase memtupsize by more
644 * than availMem / sizeof(void *) elements. In practice, we want to
645 * increase it by considerably less, because we need to leave some
646 * space for the tuples to which the new array slots will refer. We
647 * assume the new tuples will be about the same size as the tuples
648 * we've already seen, and thus we can extrapolate from the space
649 * consumption so far to estimate an appropriate new size for the
650 * memtuples array. The optimal value might be higher or lower than
651 * this estimate, but it's hard to know that in advance. We again
652 * clamp at INT_MAX tuples.
653 *
654 * This calculation is safe against enlarging the array so much that
655 * LACKMEM becomes true, because the memory currently used includes
656 * the present array; thus, there would be enough allowedMem for the
657 * new array elements even if no other memory were currently used.
658 *
659 * We do the arithmetic in float8, because otherwise the product of
660 * memtupsize and allowedMem could overflow. Any inaccuracy in the
661 * result should be insignificant; but even if we computed a
662 * completely insane result, the checks below will prevent anything
663 * really bad from happening.
664 */
665 double grow_ratio;
666
667 grow_ratio = (double) state->allowedMem / (double) memNowUsed;
668 if (memtupsize * grow_ratio < INT_MAX)
669 newmemtupsize = (int) (memtupsize * grow_ratio);
670 else
671 newmemtupsize = INT_MAX;
672
673 /* We won't make any further enlargement attempts */
674 state->growmemtuples = false;
675 }
676
677 /* Must enlarge array by at least one element, else report failure */
678 if (newmemtupsize <= memtupsize)
679 goto noalloc;
680
681 /*
682 * On a 32-bit machine, allowedMem could exceed MaxAllocHugeSize. Clamp
683 * to ensure our request won't be rejected. Note that we can easily
684 * exhaust address space before facing this outcome. (This is presently
685 * impossible due to guc.c's MAX_KILOBYTES limitation on work_mem, but
686 * don't rely on that at this distance.)
687 */
688 if ((Size) newmemtupsize >= MaxAllocHugeSize / sizeof(void *))
689 {
690 newmemtupsize = (int) (MaxAllocHugeSize / sizeof(void *));
691 state->growmemtuples = false; /* can't grow any more */
692 }
693
694 /*
695 * We need to be sure that we do not cause LACKMEM to become true, else
696 * the space management algorithm will go nuts. The code above should
697 * never generate a dangerous request, but to be safe, check explicitly
698 * that the array growth fits within availMem. (We could still cause
699 * LACKMEM if the memory chunk overhead associated with the memtuples
700 * array were to increase. That shouldn't happen because we chose the
701 * initial array size large enough to ensure that palloc will be treating
702 * both old and new arrays as separate chunks. But we'll check LACKMEM
703 * explicitly below just in case.)
704 */
705 if (state->availMem < (int64) ((newmemtupsize - memtupsize) * sizeof(void *)))
706 goto noalloc;
707
708 /* OK, do it */
710 state->memtupsize = newmemtupsize;
711 state->memtuples = (void **)
712 repalloc_huge(state->memtuples,
713 state->memtupsize * sizeof(void *));
715 if (LACKMEM(state))
716 elog(ERROR, "unexpected out-of-memory situation in tuplestore");
717 return true;
718
719noalloc:
720 /* If for any reason we didn't realloc, shut off future attempts */
721 state->growmemtuples = false;
722 return false;
723}
int64_t int64
Definition: c.h:485
size_t Size
Definition: c.h:562
#define ERROR
Definition: elog.h:39
#define elog(elevel,...)
Definition: elog.h:225
void * repalloc_huge(void *pointer, Size size)
Definition: mcxt.c:1672
#define MaxAllocHugeSize
Definition: memutils.h:45
#define LACKMEM(state)
Definition: tuplestore.c:188
#define FREEMEM(state, amt)
Definition: tuplestore.c:190

References elog, ERROR, FREEMEM, GetMemoryChunkSpace(), LACKMEM, MaxAllocHugeSize, repalloc_huge(), and USEMEM.

Referenced by tuplestore_puttuple_common().

◆ readtup_heap()

static void * readtup_heap ( Tuplestorestate state,
unsigned int  len 
)
static

Definition at line 1620 of file tuplestore.c.

1621{
1622 unsigned int tupbodylen = len - sizeof(int);
1623 unsigned int tuplen = tupbodylen + MINIMAL_TUPLE_DATA_OFFSET;
1624 MinimalTuple tuple = (MinimalTuple) palloc(tuplen);
1625 char *tupbody = (char *) tuple + MINIMAL_TUPLE_DATA_OFFSET;
1626
1627 /* read in the tuple proper */
1628 tuple->t_len = tuplen;
1629 BufFileReadExact(state->myfile, tupbody, tupbodylen);
1630 if (state->backward) /* need trailing length word? */
1631 BufFileReadExact(state->myfile, &tuplen, sizeof(tuplen));
1632 return tuple;
1633}
void BufFileReadExact(BufFile *file, void *ptr, size_t size)
Definition: buffile.c:654
MinimalTupleData * MinimalTuple
Definition: htup.h:27
#define MINIMAL_TUPLE_DATA_OFFSET
Definition: htup_details.h:621
void * palloc(Size size)
Definition: mcxt.c:1317

References BufFileReadExact(), len, MINIMAL_TUPLE_DATA_OFFSET, palloc(), and MinimalTupleData::t_len.

Referenced by tuplestore_begin_heap().

◆ tuplestore_advance()

bool tuplestore_advance ( Tuplestorestate state,
bool  forward 
)

Definition at line 1162 of file tuplestore.c.

1163{
1164 void *tuple;
1165 bool should_free;
1166
1167 tuple = tuplestore_gettuple(state, forward, &should_free);
1168
1169 if (tuple)
1170 {
1171 if (should_free)
1172 pfree(tuple);
1173 return true;
1174 }
1175 else
1176 {
1177 return false;
1178 }
1179}
void pfree(void *pointer)
Definition: mcxt.c:1521
static void * tuplestore_gettuple(Tuplestorestate *state, bool forward, bool *should_free)
Definition: tuplestore.c:955

References pfree(), and tuplestore_gettuple().

Referenced by CteScanNext(), ExecMaterial(), and window_gettupleslot().

◆ tuplestore_alloc_read_pointer()

int tuplestore_alloc_read_pointer ( Tuplestorestate state,
int  eflags 
)

Definition at line 395 of file tuplestore.c.

396{
397 /* Check for possible increase of requirements */
398 if (state->status != TSS_INMEM || state->memtupcount != 0)
399 {
400 if ((state->eflags | eflags) != state->eflags)
401 elog(ERROR, "too late to require new tuplestore eflags");
402 }
403
404 /* Make room for another read pointer if needed */
405 if (state->readptrcount >= state->readptrsize)
406 {
407 int newcnt = state->readptrsize * 2;
408
409 state->readptrs = (TSReadPointer *)
410 repalloc(state->readptrs, newcnt * sizeof(TSReadPointer));
411 state->readptrsize = newcnt;
412 }
413
414 /* And set it up */
415 state->readptrs[state->readptrcount] = state->readptrs[0];
416 state->readptrs[state->readptrcount].eflags = eflags;
417
418 state->eflags |= eflags;
419
420 return state->readptrcount++;
421}
void * repalloc(void *pointer, Size size)
Definition: mcxt.c:1541

References elog, ERROR, repalloc(), and TSS_INMEM.

Referenced by ExecInitCteScan(), ExecInitNamedTuplestoreScan(), ExecMaterial(), and prepare_tuplestore().

◆ tuplestore_ateof()

bool tuplestore_ateof ( Tuplestorestate state)

Definition at line 591 of file tuplestore.c.

592{
593 return state->readptrs[state->activeptr].eof_reached;
594}

Referenced by CteScanNext(), and ExecMaterial().

◆ tuplestore_begin_common()

static Tuplestorestate * tuplestore_begin_common ( int  eflags,
bool  interXact,
int  maxKBytes 
)
static

Definition at line 256 of file tuplestore.c.

257{
259
261
262 state->status = TSS_INMEM;
263 state->eflags = eflags;
264 state->interXact = interXact;
265 state->truncated = false;
266 state->usedDisk = false;
267 state->maxSpace = 0;
268 state->allowedMem = maxKBytes * 1024L;
269 state->availMem = state->allowedMem;
270 state->myfile = NULL;
271
272 /*
273 * The palloc/pfree pattern for tuple memory is in a FIFO pattern. A
274 * generation context is perfectly suited for this.
275 */
277 "tuplestore tuples",
279 state->resowner = CurrentResourceOwner;
280
281 state->memtupdeleted = 0;
282 state->memtupcount = 0;
283 state->tuples = 0;
284
285 /*
286 * Initial size of array must be more than ALLOCSET_SEPARATE_THRESHOLD;
287 * see comments in grow_memtuples().
288 */
289 state->memtupsize = Max(16384 / sizeof(void *),
290 ALLOCSET_SEPARATE_THRESHOLD / sizeof(void *) + 1);
291
292 state->growmemtuples = true;
293 state->memtuples = (void **) palloc(state->memtupsize * sizeof(void *));
294
296
297 state->activeptr = 0;
298 state->readptrcount = 1;
299 state->readptrsize = 8; /* arbitrary */
300 state->readptrs = (TSReadPointer *)
301 palloc(state->readptrsize * sizeof(TSReadPointer));
302
303 state->readptrs[0].eflags = eflags;
304 state->readptrs[0].eof_reached = false;
305 state->readptrs[0].current = 0;
306
307 return state;
308}
#define Max(x, y)
Definition: c.h:955
MemoryContext GenerationContextCreate(MemoryContext parent, const char *name, Size minContextSize, Size initBlockSize, Size maxBlockSize)
Definition: generation.c:160
void * palloc0(Size size)
Definition: mcxt.c:1347
MemoryContext CurrentMemoryContext
Definition: mcxt.c:143
#define ALLOCSET_DEFAULT_SIZES
Definition: memutils.h:160
#define ALLOCSET_SEPARATE_THRESHOLD
Definition: memutils.h:187
ResourceOwner CurrentResourceOwner
Definition: resowner.c:165

References ALLOCSET_DEFAULT_SIZES, ALLOCSET_SEPARATE_THRESHOLD, CurrentMemoryContext, CurrentResourceOwner, GenerationContextCreate(), GetMemoryChunkSpace(), Max, palloc(), palloc0(), TSS_INMEM, and USEMEM.

Referenced by tuplestore_begin_heap().

◆ tuplestore_begin_heap()

Tuplestorestate * tuplestore_begin_heap ( bool  randomAccess,
bool  interXact,
int  maxKBytes 
)

Definition at line 330 of file tuplestore.c.

331{
333 int eflags;
334
335 /*
336 * This interpretation of the meaning of randomAccess is compatible with
337 * the pre-8.3 behavior of tuplestores.
338 */
339 eflags = randomAccess ?
342
343 state = tuplestore_begin_common(eflags, interXact, maxKBytes);
344
345 state->copytup = copytup_heap;
346 state->writetup = writetup_heap;
347 state->readtup = readtup_heap;
348
349 return state;
350}
#define EXEC_FLAG_BACKWARD
Definition: executor.h:68
#define EXEC_FLAG_REWIND
Definition: executor.h:67
static void writetup_heap(Tuplestorestate *state, void *tup)
Definition: tuplestore.c:1599
static void * copytup_heap(Tuplestorestate *state, void *tup)
Definition: tuplestore.c:1589
static Tuplestorestate * tuplestore_begin_common(int eflags, bool interXact, int maxKBytes)
Definition: tuplestore.c:256
static void * readtup_heap(Tuplestorestate *state, unsigned int len)
Definition: tuplestore.c:1620

References copytup_heap(), EXEC_FLAG_BACKWARD, EXEC_FLAG_REWIND, readtup_heap(), tuplestore_begin_common(), and writetup_heap().

Referenced by connectby(), crosstab(), exec_init_tuple_store(), ExecInitCteScan(), ExecInitRecursiveUnion(), ExecMakeTableFunctionResult(), ExecMaterial(), fmgr_sql(), get_crosstab_tuplestore(), GetCurrentFDWTuplestore(), InitMaterializedSRF(), libpqrcv_processTuples(), MakeTransitionCaptureState(), materializeResult(), plperl_return_next_internal(), pltcl_init_tuple_store(), populate_recordset_worker(), PortalCreateHoldStore(), prepare_tuplestore(), storeRow(), and tfuncFetchRows().

◆ tuplestore_clear()

void tuplestore_clear ( Tuplestorestate state)

Definition at line 430 of file tuplestore.c.

431{
432 int i;
433 TSReadPointer *readptr;
434
435 /* update the maxSpace before doing any USEMEM/FREEMEM adjustments */
437
438 if (state->myfile)
439 BufFileClose(state->myfile);
440 state->myfile = NULL;
441
442#ifdef USE_ASSERT_CHECKING
443 {
444 int64 availMem = state->availMem;
445
446 /*
447 * Below, we reset the memory context for storing tuples. To save
448 * from having to always call GetMemoryChunkSpace() on all stored
449 * tuples, we adjust the availMem to forget all the tuples and just
450 * recall USEMEM for the space used by the memtuples array. Here we
451 * just Assert that's correct and the memory tracking hasn't gone
452 * wrong anywhere.
453 */
454 for (i = state->memtupdeleted; i < state->memtupcount; i++)
455 availMem += GetMemoryChunkSpace(state->memtuples[i]);
456
457 availMem += GetMemoryChunkSpace(state->memtuples);
458
459 Assert(availMem == state->allowedMem);
460 }
461#endif
462
463 /* clear the memory consumed by the memory tuples */
464 MemoryContextReset(state->context);
465
466 /*
467 * Zero the used memory and re-consume the space for the memtuples array.
468 * This saves having to FREEMEM for each stored tuple.
469 */
470 state->availMem = state->allowedMem;
472
473 state->status = TSS_INMEM;
474 state->truncated = false;
475 state->memtupdeleted = 0;
476 state->memtupcount = 0;
477 state->tuples = 0;
478 readptr = state->readptrs;
479 for (i = 0; i < state->readptrcount; readptr++, i++)
480 {
481 readptr->eof_reached = false;
482 readptr->current = 0;
483 }
484}
void BufFileClose(BufFile *file)
Definition: buffile.c:412
#define Assert(condition)
Definition: c.h:815
void MemoryContextReset(MemoryContext context)
Definition: mcxt.c:383
static void tuplestore_updatemax(Tuplestorestate *state)
Definition: tuplestore.c:1508

References Assert, BufFileClose(), TSReadPointer::current, TSReadPointer::eof_reached, GetMemoryChunkSpace(), i, MemoryContextReset(), TSS_INMEM, tuplestore_updatemax(), and USEMEM.

Referenced by ExecRecursiveUnion(), ExecReScanCteScan(), ExecReScanRecursiveUnion(), fmgr_sql(), and release_partition().

◆ tuplestore_copy_read_pointer()

void tuplestore_copy_read_pointer ( Tuplestorestate state,
int  srcptr,
int  destptr 
)

Definition at line 1320 of file tuplestore.c.

1322{
1323 TSReadPointer *sptr = &state->readptrs[srcptr];
1324 TSReadPointer *dptr = &state->readptrs[destptr];
1325
1326 Assert(srcptr >= 0 && srcptr < state->readptrcount);
1327 Assert(destptr >= 0 && destptr < state->readptrcount);
1328
1329 /* Assigning to self is a no-op */
1330 if (srcptr == destptr)
1331 return;
1332
1333 if (dptr->eflags != sptr->eflags)
1334 {
1335 /* Possible change of overall eflags, so copy and then recompute */
1336 int eflags;
1337 int i;
1338
1339 *dptr = *sptr;
1340 eflags = state->readptrs[0].eflags;
1341 for (i = 1; i < state->readptrcount; i++)
1342 eflags |= state->readptrs[i].eflags;
1343 state->eflags = eflags;
1344 }
1345 else
1346 *dptr = *sptr;
1347
1348 switch (state->status)
1349 {
1350 case TSS_INMEM:
1351 case TSS_WRITEFILE:
1352 /* no work */
1353 break;
1354 case TSS_READFILE:
1355
1356 /*
1357 * This case is a bit tricky since the active read pointer's
1358 * position corresponds to the seek point, not what is in its
1359 * variables. Assigning to the active requires a seek, and
1360 * assigning from the active requires a tell, except when
1361 * eof_reached.
1362 */
1363 if (destptr == state->activeptr)
1364 {
1365 if (dptr->eof_reached)
1366 {
1367 if (BufFileSeek(state->myfile,
1368 state->writepos_file,
1369 state->writepos_offset,
1370 SEEK_SET) != 0)
1371 ereport(ERROR,
1373 errmsg("could not seek in tuplestore temporary file")));
1374 }
1375 else
1376 {
1377 if (BufFileSeek(state->myfile,
1378 dptr->file, dptr->offset,
1379 SEEK_SET) != 0)
1380 ereport(ERROR,
1382 errmsg("could not seek in tuplestore temporary file")));
1383 }
1384 }
1385 else if (srcptr == state->activeptr)
1386 {
1387 if (!dptr->eof_reached)
1388 BufFileTell(state->myfile,
1389 &dptr->file,
1390 &dptr->offset);
1391 }
1392 break;
1393 default:
1394 elog(ERROR, "invalid tuplestore state");
1395 break;
1396 }
1397}
int BufFileSeek(BufFile *file, int fileno, off_t offset, int whence)
Definition: buffile.c:740
int errcode_for_file_access(void)
Definition: elog.c:876
int errmsg(const char *fmt,...)
Definition: elog.c:1070
#define ereport(elevel,...)
Definition: elog.h:149

References Assert, BufFileSeek(), BufFileTell(), TSReadPointer::eflags, elog, TSReadPointer::eof_reached, ereport, errcode_for_file_access(), errmsg(), ERROR, TSReadPointer::file, i, TSReadPointer::offset, TSS_INMEM, TSS_READFILE, and TSS_WRITEFILE.

Referenced by ExecMaterialMarkPos(), and ExecMaterialRestrPos().

◆ tuplestore_end()

◆ tuplestore_get_stats()

void tuplestore_get_stats ( Tuplestorestate state,
char **  max_storage_type,
int64 max_space 
)

Definition at line 1533 of file tuplestore.c.

1535{
1537
1538 if (state->usedDisk)
1539 *max_storage_type = "Disk";
1540 else
1541 *max_storage_type = "Memory";
1542
1543 *max_space = state->maxSpace;
1544}

References tuplestore_updatemax().

Referenced by show_ctescan_info(), show_material_info(), show_recursive_union_info(), show_table_func_scan_info(), and show_windowagg_info().

◆ tuplestore_gettuple()

static void * tuplestore_gettuple ( Tuplestorestate state,
bool  forward,
bool *  should_free 
)
static

Definition at line 955 of file tuplestore.c.

957{
958 TSReadPointer *readptr = &state->readptrs[state->activeptr];
959 unsigned int tuplen;
960 void *tup;
961
962 Assert(forward || (readptr->eflags & EXEC_FLAG_BACKWARD));
963
964 switch (state->status)
965 {
966 case TSS_INMEM:
967 *should_free = false;
968 if (forward)
969 {
970 if (readptr->eof_reached)
971 return NULL;
972 if (readptr->current < state->memtupcount)
973 {
974 /* We have another tuple, so return it */
975 return state->memtuples[readptr->current++];
976 }
977 readptr->eof_reached = true;
978 return NULL;
979 }
980 else
981 {
982 /*
983 * if all tuples are fetched already then we return last
984 * tuple, else tuple before last returned.
985 */
986 if (readptr->eof_reached)
987 {
988 readptr->current = state->memtupcount;
989 readptr->eof_reached = false;
990 }
991 else
992 {
993 if (readptr->current <= state->memtupdeleted)
994 {
995 Assert(!state->truncated);
996 return NULL;
997 }
998 readptr->current--; /* last returned tuple */
999 }
1000 if (readptr->current <= state->memtupdeleted)
1001 {
1002 Assert(!state->truncated);
1003 return NULL;
1004 }
1005 return state->memtuples[readptr->current - 1];
1006 }
1007 break;
1008
1009 case TSS_WRITEFILE:
1010 /* Skip state change if we'll just return NULL */
1011 if (readptr->eof_reached && forward)
1012 return NULL;
1013
1014 /*
1015 * Switch from writing to reading.
1016 */
1017 BufFileTell(state->myfile,
1018 &state->writepos_file, &state->writepos_offset);
1019 if (!readptr->eof_reached)
1020 if (BufFileSeek(state->myfile,
1021 readptr->file, readptr->offset,
1022 SEEK_SET) != 0)
1023 ereport(ERROR,
1025 errmsg("could not seek in tuplestore temporary file")));
1026 state->status = TSS_READFILE;
1027 /* FALLTHROUGH */
1028
1029 case TSS_READFILE:
1030 *should_free = true;
1031 if (forward)
1032 {
1033 if ((tuplen = getlen(state, true)) != 0)
1034 {
1035 tup = READTUP(state, tuplen);
1036 return tup;
1037 }
1038 else
1039 {
1040 readptr->eof_reached = true;
1041 return NULL;
1042 }
1043 }
1044
1045 /*
1046 * Backward.
1047 *
1048 * if all tuples are fetched already then we return last tuple,
1049 * else tuple before last returned.
1050 *
1051 * Back up to fetch previously-returned tuple's ending length
1052 * word. If seek fails, assume we are at start of file.
1053 */
1054 if (BufFileSeek(state->myfile, 0, -(long) sizeof(unsigned int),
1055 SEEK_CUR) != 0)
1056 {
1057 /* even a failed backwards fetch gets you out of eof state */
1058 readptr->eof_reached = false;
1059 Assert(!state->truncated);
1060 return NULL;
1061 }
1062 tuplen = getlen(state, false);
1063
1064 if (readptr->eof_reached)
1065 {
1066 readptr->eof_reached = false;
1067 /* We will return the tuple returned before returning NULL */
1068 }
1069 else
1070 {
1071 /*
1072 * Back up to get ending length word of tuple before it.
1073 */
1074 if (BufFileSeek(state->myfile, 0,
1075 -(long) (tuplen + 2 * sizeof(unsigned int)),
1076 SEEK_CUR) != 0)
1077 {
1078 /*
1079 * If that fails, presumably the prev tuple is the first
1080 * in the file. Back up so that it becomes next to read
1081 * in forward direction (not obviously right, but that is
1082 * what in-memory case does).
1083 */
1084 if (BufFileSeek(state->myfile, 0,
1085 -(long) (tuplen + sizeof(unsigned int)),
1086 SEEK_CUR) != 0)
1087 ereport(ERROR,
1089 errmsg("could not seek in tuplestore temporary file")));
1090 Assert(!state->truncated);
1091 return NULL;
1092 }
1093 tuplen = getlen(state, false);
1094 }
1095
1096 /*
1097 * Now we have the length of the prior tuple, back up and read it.
1098 * Note: READTUP expects we are positioned after the initial
1099 * length word of the tuple, so back up to that point.
1100 */
1101 if (BufFileSeek(state->myfile, 0,
1102 -(long) tuplen,
1103 SEEK_CUR) != 0)
1104 ereport(ERROR,
1106 errmsg("could not seek in tuplestore temporary file")));
1107 tup = READTUP(state, tuplen);
1108 return tup;
1109
1110 default:
1111 elog(ERROR, "invalid tuplestore state");
1112 return NULL; /* keep compiler quiet */
1113 }
1114}
#define READTUP(state, len)
Definition: tuplestore.c:187
static unsigned int getlen(Tuplestorestate *state, bool eofOK)
Definition: tuplestore.c:1565

References Assert, BufFileSeek(), BufFileTell(), TSReadPointer::current, TSReadPointer::eflags, elog, TSReadPointer::eof_reached, ereport, errcode_for_file_access(), errmsg(), ERROR, EXEC_FLAG_BACKWARD, TSReadPointer::file, getlen(), TSReadPointer::offset, READTUP, TSS_INMEM, TSS_READFILE, and TSS_WRITEFILE.

Referenced by tuplestore_advance(), tuplestore_gettupleslot(), and tuplestore_skiptuples().

◆ tuplestore_gettupleslot()

bool tuplestore_gettupleslot ( Tuplestorestate state,
bool  forward,
bool  copy,
TupleTableSlot slot 
)

Definition at line 1130 of file tuplestore.c.

1132{
1133 MinimalTuple tuple;
1134 bool should_free;
1135
1136 tuple = (MinimalTuple) tuplestore_gettuple(state, forward, &should_free);
1137
1138 if (tuple)
1139 {
1140 if (copy && !should_free)
1141 {
1142 tuple = heap_copy_minimal_tuple(tuple);
1143 should_free = true;
1144 }
1145 ExecStoreMinimalTuple(tuple, slot, should_free);
1146 return true;
1147 }
1148 else
1149 {
1150 ExecClearTuple(slot);
1151 return false;
1152 }
1153}
TupleTableSlot * ExecStoreMinimalTuple(MinimalTuple mtup, TupleTableSlot *slot, bool shouldFree)
Definition: execTuples.c:1633
MinimalTuple heap_copy_minimal_tuple(MinimalTuple mtup)
Definition: heaptuple.c:1536
static TupleTableSlot * ExecClearTuple(TupleTableSlot *slot)
Definition: tuptable.h:454

References ExecClearTuple(), ExecStoreMinimalTuple(), heap_copy_minimal_tuple(), and tuplestore_gettuple().

Referenced by AfterTriggerExecute(), check_publications(), check_publications_origin(), CteScanNext(), ExecMakeFunctionResultSet(), ExecMaterial(), ExecWindowAgg(), fetch_remote_table_info(), fetch_table_list(), fmgr_sql(), FunctionNext(), NamedTuplestoreScanNext(), RunFromStore(), synchronize_slots(), TableFuncNext(), update_frameheadpos(), update_frametailpos(), update_grouptailpos(), validate_remote_info(), window_gettupleslot(), and WorkTableScanNext().

◆ tuplestore_in_memory()

bool tuplestore_in_memory ( Tuplestorestate state)

Definition at line 1554 of file tuplestore.c.

1555{
1556 return (state->status == TSS_INMEM);
1557}

References TSS_INMEM.

Referenced by spool_tuples().

◆ tuplestore_puttuple()

void tuplestore_puttuple ( Tuplestorestate state,
HeapTuple  tuple 
)

Definition at line 764 of file tuplestore.c.

765{
766 MemoryContext oldcxt = MemoryContextSwitchTo(state->context);
767
768 /*
769 * Copy the tuple. (Must do this even in WRITEFILE case. Note that
770 * COPYTUP includes USEMEM, so we needn't do that here.)
771 */
772 tuple = COPYTUP(state, tuple);
773
775
776 MemoryContextSwitchTo(oldcxt);
777}
static MemoryContext MemoryContextSwitchTo(MemoryContext context)
Definition: palloc.h:124
#define COPYTUP(state, tup)
Definition: tuplestore.c:185
static void tuplestore_puttuple_common(Tuplestorestate *state, void *tuple)
Definition: tuplestore.c:799

References COPYTUP, MemoryContextSwitchTo(), and tuplestore_puttuple_common().

Referenced by build_tuplestore_recursively(), crosstab(), each_object_field_end(), elements_array_element_end(), exec_stmt_return_next(), ExecMakeTableFunctionResult(), fill_hba_line(), fill_ident_line(), get_crosstab_tuplestore(), libpqrcv_processTuples(), materializeResult(), pg_available_wal_summaries(), pg_wal_summary_contents(), pgrowlocks(), plperl_return_next_internal(), pltcl_returnnext(), populate_recordset_record(), report_corruption_internal(), storeRow(), and xpath_table().

◆ tuplestore_puttuple_common()

static void tuplestore_puttuple_common ( Tuplestorestate state,
void *  tuple 
)
static

Definition at line 799 of file tuplestore.c.

800{
801 TSReadPointer *readptr;
802 int i;
803 ResourceOwner oldowner;
804 MemoryContext oldcxt;
805
806 state->tuples++;
807
808 switch (state->status)
809 {
810 case TSS_INMEM:
811
812 /*
813 * Update read pointers as needed; see API spec above.
814 */
815 readptr = state->readptrs;
816 for (i = 0; i < state->readptrcount; readptr++, i++)
817 {
818 if (readptr->eof_reached && i != state->activeptr)
819 {
820 readptr->eof_reached = false;
821 readptr->current = state->memtupcount;
822 }
823 }
824
825 /*
826 * Grow the array as needed. Note that we try to grow the array
827 * when there is still one free slot remaining --- if we fail,
828 * there'll still be room to store the incoming tuple, and then
829 * we'll switch to tape-based operation.
830 */
831 if (state->memtupcount >= state->memtupsize - 1)
832 {
833 (void) grow_memtuples(state);
834 Assert(state->memtupcount < state->memtupsize);
835 }
836
837 /* Stash the tuple in the in-memory array */
838 state->memtuples[state->memtupcount++] = tuple;
839
840 /*
841 * Done if we still fit in available memory and have array slots.
842 */
843 if (state->memtupcount < state->memtupsize && !LACKMEM(state))
844 return;
845
846 /*
847 * Nope; time to switch to tape-based operation. Make sure that
848 * the temp file(s) are created in suitable temp tablespaces.
849 */
851
852 /* associate the file with the store's resource owner */
853 oldowner = CurrentResourceOwner;
854 CurrentResourceOwner = state->resowner;
855
856 /*
857 * We switch out of the state->context as this is a generation
858 * context, which isn't ideal for allocations relating to the
859 * BufFile.
860 */
861 oldcxt = MemoryContextSwitchTo(state->context->parent);
862
863 state->myfile = BufFileCreateTemp(state->interXact);
864
865 MemoryContextSwitchTo(oldcxt);
866
867 CurrentResourceOwner = oldowner;
868
869 /*
870 * Freeze the decision about whether trailing length words will be
871 * used. We can't change this choice once data is on tape, even
872 * though callers might drop the requirement.
873 */
874 state->backward = (state->eflags & EXEC_FLAG_BACKWARD) != 0;
875
876 /*
877 * Update the maximum space used before dumping the tuples. It's
878 * possible that more space will be used by the tuples in memory
879 * than the space that will be used on disk.
880 */
882
883 state->status = TSS_WRITEFILE;
885 break;
886 case TSS_WRITEFILE:
887
888 /*
889 * Update read pointers as needed; see API spec above. Note:
890 * BufFileTell is quite cheap, so not worth trying to avoid
891 * multiple calls.
892 */
893 readptr = state->readptrs;
894 for (i = 0; i < state->readptrcount; readptr++, i++)
895 {
896 if (readptr->eof_reached && i != state->activeptr)
897 {
898 readptr->eof_reached = false;
899 BufFileTell(state->myfile,
900 &readptr->file,
901 &readptr->offset);
902 }
903 }
904
905 WRITETUP(state, tuple);
906 break;
907 case TSS_READFILE:
908
909 /*
910 * Switch from reading to writing.
911 */
912 if (!state->readptrs[state->activeptr].eof_reached)
913 BufFileTell(state->myfile,
914 &state->readptrs[state->activeptr].file,
915 &state->readptrs[state->activeptr].offset);
916 if (BufFileSeek(state->myfile,
917 state->writepos_file, state->writepos_offset,
918 SEEK_SET) != 0)
921 errmsg("could not seek in tuplestore temporary file")));
922 state->status = TSS_WRITEFILE;
923
924 /*
925 * Update read pointers as needed; see API spec above.
926 */
927 readptr = state->readptrs;
928 for (i = 0; i < state->readptrcount; readptr++, i++)
929 {
930 if (readptr->eof_reached && i != state->activeptr)
931 {
932 readptr->eof_reached = false;
933 readptr->file = state->writepos_file;
934 readptr->offset = state->writepos_offset;
935 }
936 }
937
938 WRITETUP(state, tuple);
939 break;
940 default:
941 elog(ERROR, "invalid tuplestore state");
942 break;
943 }
944}
void PrepareTempTablespaces(void)
Definition: tablespace.c:1331
BufFile * BufFileCreateTemp(bool interXact)
Definition: buffile.c:193
static bool grow_memtuples(Tuplestorestate *state)
Definition: tuplestore.c:612
static void dumptuples(Tuplestorestate *state)
Definition: tuplestore.c:1258

References Assert, BufFileCreateTemp(), BufFileSeek(), BufFileTell(), TSReadPointer::current, CurrentResourceOwner, dumptuples(), elog, TSReadPointer::eof_reached, ereport, errcode_for_file_access(), errmsg(), ERROR, EXEC_FLAG_BACKWARD, TSReadPointer::file, grow_memtuples(), i, LACKMEM, MemoryContextSwitchTo(), TSReadPointer::offset, PrepareTempTablespaces(), TSS_INMEM, TSS_READFILE, TSS_WRITEFILE, tuplestore_updatemax(), and WRITETUP.

Referenced by tuplestore_puttuple(), tuplestore_puttupleslot(), and tuplestore_putvalues().

◆ tuplestore_puttupleslot()

void tuplestore_puttupleslot ( Tuplestorestate state,
TupleTableSlot slot 
)

Definition at line 742 of file tuplestore.c.

744{
745 MinimalTuple tuple;
746 MemoryContext oldcxt = MemoryContextSwitchTo(state->context);
747
748 /*
749 * Form a MinimalTuple in working memory
750 */
751 tuple = ExecCopySlotMinimalTuple(slot);
753
755
756 MemoryContextSwitchTo(oldcxt);
757}
static MinimalTuple ExecCopySlotMinimalTuple(TupleTableSlot *slot)
Definition: tuptable.h:492

References ExecCopySlotMinimalTuple(), GetMemoryChunkSpace(), MemoryContextSwitchTo(), tuplestore_puttuple_common(), and USEMEM.

Referenced by AfterTriggerSaveEvent(), begin_partition(), CteScanNext(), ExecMaterial(), ExecRecursiveUnion(), spool_tuples(), sqlfunction_receive(), TransitionTableAddTuple(), tstoreReceiveSlot_notoast(), and tstoreReceiveSlot_tupmap().

◆ tuplestore_putvalues()

void tuplestore_putvalues ( Tuplestorestate state,
TupleDesc  tdesc,
const Datum values,
const bool *  isnull 
)

Definition at line 784 of file tuplestore.c.

786{
787 MinimalTuple tuple;
788 MemoryContext oldcxt = MemoryContextSwitchTo(state->context);
789
790 tuple = heap_form_minimal_tuple(tdesc, values, isnull);
792
794
795 MemoryContextSwitchTo(oldcxt);
796}
static Datum values[MAXATTR]
Definition: bootstrap.c:151
MinimalTuple heap_form_minimal_tuple(TupleDesc tupleDescriptor, const Datum *values, const bool *isnull)
Definition: heaptuple.c:1453

References GetMemoryChunkSpace(), heap_form_minimal_tuple(), MemoryContextSwitchTo(), tuplestore_puttuple_common(), USEMEM, and values.

Referenced by brin_page_items(), dblink_get_notify(), each_worker_jsonb(), elements_worker_jsonb(), exec_stmt_return_next(), ExecMakeTableFunctionResult(), get_altertable_subcmdinfo(), get_available_versions_for_extension(), GetWALBlockInfo(), GetWALRecordsInfo(), GetXLogSummaryStats(), gist_page_items(), gist_page_items_bytea(), LogicalOutputWrite(), pg_available_extensions(), pg_config(), pg_cursor(), pg_event_trigger_ddl_commands(), pg_event_trigger_dropped_objects(), pg_extension_update_paths(), pg_get_replication_slots(), pg_get_shmem_allocations(), pg_get_wait_events(), pg_ls_dir(), pg_ls_dir_files(), pg_options_to_table(), pg_prepared_statement(), pg_show_replication_origin_status(), pg_stat_get_activity(), pg_stat_get_progress_info(), pg_stat_get_recovery_prefetch(), pg_stat_get_slru(), pg_stat_get_subscription(), pg_stat_get_wal_senders(), pg_stat_io_build_tuples(), pg_stat_statements_internal(), pg_tablespace_databases(), plperl_return_next_internal(), pltcl_returnnext(), postgres_fdw_get_connections_internal(), PutMemoryContextsStatsTupleStore(), show_all_file_settings(), split_text_accum_result(), tfuncLoadRows(), and tstoreReceiveSlot_detoast().

◆ tuplestore_rescan()

void tuplestore_rescan ( Tuplestorestate state)

Definition at line 1285 of file tuplestore.c.

1286{
1287 TSReadPointer *readptr = &state->readptrs[state->activeptr];
1288
1289 Assert(readptr->eflags & EXEC_FLAG_REWIND);
1290 Assert(!state->truncated);
1291
1292 switch (state->status)
1293 {
1294 case TSS_INMEM:
1295 readptr->eof_reached = false;
1296 readptr->current = 0;
1297 break;
1298 case TSS_WRITEFILE:
1299 readptr->eof_reached = false;
1300 readptr->file = 0;
1301 readptr->offset = 0;
1302 break;
1303 case TSS_READFILE:
1304 readptr->eof_reached = false;
1305 if (BufFileSeek(state->myfile, 0, 0, SEEK_SET) != 0)
1306 ereport(ERROR,
1308 errmsg("could not seek in tuplestore temporary file")));
1309 break;
1310 default:
1311 elog(ERROR, "invalid tuplestore state");
1312 break;
1313 }
1314}

References Assert, BufFileSeek(), TSReadPointer::current, TSReadPointer::eflags, elog, TSReadPointer::eof_reached, ereport, errcode_for_file_access(), errmsg(), ERROR, EXEC_FLAG_REWIND, TSReadPointer::file, TSReadPointer::offset, TSS_INMEM, TSS_READFILE, and TSS_WRITEFILE.

Referenced by DoPortalRewind(), ExecInitCteScan(), ExecInitNamedTuplestoreScan(), ExecReScanCteScan(), ExecReScanFunctionScan(), ExecReScanMaterial(), ExecReScanNamedTuplestoreScan(), ExecReScanTableFuncScan(), ExecReScanWorkTableScan(), FunctionNext(), and PersistHoldablePortal().

◆ tuplestore_select_read_pointer()

void tuplestore_select_read_pointer ( Tuplestorestate state,
int  ptr 
)

Definition at line 507 of file tuplestore.c.

508{
509 TSReadPointer *readptr;
510 TSReadPointer *oldptr;
511
512 Assert(ptr >= 0 && ptr < state->readptrcount);
513
514 /* No work if already active */
515 if (ptr == state->activeptr)
516 return;
517
518 readptr = &state->readptrs[ptr];
519 oldptr = &state->readptrs[state->activeptr];
520
521 switch (state->status)
522 {
523 case TSS_INMEM:
524 case TSS_WRITEFILE:
525 /* no work */
526 break;
527 case TSS_READFILE:
528
529 /*
530 * First, save the current read position in the pointer about to
531 * become inactive.
532 */
533 if (!oldptr->eof_reached)
534 BufFileTell(state->myfile,
535 &oldptr->file,
536 &oldptr->offset);
537
538 /*
539 * We have to make the temp file's seek position equal to the
540 * logical position of the new read pointer. In eof_reached
541 * state, that's the EOF, which we have available from the saved
542 * write position.
543 */
544 if (readptr->eof_reached)
545 {
546 if (BufFileSeek(state->myfile,
547 state->writepos_file,
548 state->writepos_offset,
549 SEEK_SET) != 0)
552 errmsg("could not seek in tuplestore temporary file")));
553 }
554 else
555 {
556 if (BufFileSeek(state->myfile,
557 readptr->file,
558 readptr->offset,
559 SEEK_SET) != 0)
562 errmsg("could not seek in tuplestore temporary file")));
563 }
564 break;
565 default:
566 elog(ERROR, "invalid tuplestore state");
567 break;
568 }
569
570 state->activeptr = ptr;
571}

References Assert, BufFileSeek(), BufFileTell(), elog, TSReadPointer::eof_reached, ereport, errcode_for_file_access(), errmsg(), ERROR, TSReadPointer::file, TSReadPointer::offset, TSS_INMEM, TSS_READFILE, and TSS_WRITEFILE.

Referenced by CteScanNext(), ExecInitCteScan(), ExecInitNamedTuplestoreScan(), ExecReScanCteScan(), ExecReScanNamedTuplestoreScan(), ExecWindowAgg(), NamedTuplestoreScanNext(), update_frameheadpos(), update_frametailpos(), update_grouptailpos(), window_gettupleslot(), and WinSetMarkPosition().

◆ tuplestore_set_eflags()

void tuplestore_set_eflags ( Tuplestorestate state,
int  eflags 
)

Definition at line 371 of file tuplestore.c.

372{
373 int i;
374
375 if (state->status != TSS_INMEM || state->memtupcount != 0)
376 elog(ERROR, "too late to call tuplestore_set_eflags");
377
378 state->readptrs[0].eflags = eflags;
379 for (i = 1; i < state->readptrcount; i++)
380 eflags |= state->readptrs[i].eflags;
381 state->eflags = eflags;
382}

References elog, ERROR, i, and TSS_INMEM.

Referenced by ExecInitCteScan(), ExecMaterial(), and prepare_tuplestore().

◆ tuplestore_skiptuples()

bool tuplestore_skiptuples ( Tuplestorestate state,
int64  ntuples,
bool  forward 
)

Definition at line 1187 of file tuplestore.c.

1188{
1189 TSReadPointer *readptr = &state->readptrs[state->activeptr];
1190
1191 Assert(forward || (readptr->eflags & EXEC_FLAG_BACKWARD));
1192
1193 if (ntuples <= 0)
1194 return true;
1195
1196 switch (state->status)
1197 {
1198 case TSS_INMEM:
1199 if (forward)
1200 {
1201 if (readptr->eof_reached)
1202 return false;
1203 if (state->memtupcount - readptr->current >= ntuples)
1204 {
1205 readptr->current += ntuples;
1206 return true;
1207 }
1208 readptr->current = state->memtupcount;
1209 readptr->eof_reached = true;
1210 return false;
1211 }
1212 else
1213 {
1214 if (readptr->eof_reached)
1215 {
1216 readptr->current = state->memtupcount;
1217 readptr->eof_reached = false;
1218 ntuples--;
1219 }
1220 if (readptr->current - state->memtupdeleted > ntuples)
1221 {
1222 readptr->current -= ntuples;
1223 return true;
1224 }
1225 Assert(!state->truncated);
1226 readptr->current = state->memtupdeleted;
1227 return false;
1228 }
1229 break;
1230
1231 default:
1232 /* We don't currently try hard to optimize other cases */
1233 while (ntuples-- > 0)
1234 {
1235 void *tuple;
1236 bool should_free;
1237
1238 tuple = tuplestore_gettuple(state, forward, &should_free);
1239
1240 if (tuple == NULL)
1241 return false;
1242 if (should_free)
1243 pfree(tuple);
1245 }
1246 return true;
1247 }
1248}
#define CHECK_FOR_INTERRUPTS()
Definition: miscadmin.h:122

References Assert, CHECK_FOR_INTERRUPTS, TSReadPointer::current, TSReadPointer::eflags, TSReadPointer::eof_reached, EXEC_FLAG_BACKWARD, pfree(), TSS_INMEM, and tuplestore_gettuple().

Referenced by PersistHoldablePortal(), window_gettupleslot(), and WinSetMarkPosition().

◆ tuplestore_trim()

void tuplestore_trim ( Tuplestorestate state)

Definition at line 1412 of file tuplestore.c.

1413{
1414 int oldest;
1415 int nremove;
1416 int i;
1417
1418 /*
1419 * Truncation is disallowed if any read pointer requires rewind
1420 * capability.
1421 */
1422 if (state->eflags & EXEC_FLAG_REWIND)
1423 return;
1424
1425 /*
1426 * We don't bother trimming temp files since it usually would mean more
1427 * work than just letting them sit in kernel buffers until they age out.
1428 */
1429 if (state->status != TSS_INMEM)
1430 return;
1431
1432 /* Find the oldest read pointer */
1433 oldest = state->memtupcount;
1434 for (i = 0; i < state->readptrcount; i++)
1435 {
1436 if (!state->readptrs[i].eof_reached)
1437 oldest = Min(oldest, state->readptrs[i].current);
1438 }
1439
1440 /*
1441 * Note: you might think we could remove all the tuples before the oldest
1442 * "current", since that one is the next to be returned. However, since
1443 * tuplestore_gettuple returns a direct pointer to our internal copy of
1444 * the tuple, it's likely that the caller has still got the tuple just
1445 * before "current" referenced in a slot. So we keep one extra tuple
1446 * before the oldest "current". (Strictly speaking, we could require such
1447 * callers to use the "copy" flag to tuplestore_gettupleslot, but for
1448 * efficiency we allow this one case to not use "copy".)
1449 */
1450 nremove = oldest - 1;
1451 if (nremove <= 0)
1452 return; /* nothing to do */
1453
1454 Assert(nremove >= state->memtupdeleted);
1455 Assert(nremove <= state->memtupcount);
1456
1457 /* before freeing any memory, update the statistics */
1459
1460 /* Release no-longer-needed tuples */
1461 for (i = state->memtupdeleted; i < nremove; i++)
1462 {
1463 FREEMEM(state, GetMemoryChunkSpace(state->memtuples[i]));
1464 pfree(state->memtuples[i]);
1465 state->memtuples[i] = NULL;
1466 }
1467 state->memtupdeleted = nremove;
1468
1469 /* mark tuplestore as truncated (used for Assert crosschecks only) */
1470 state->truncated = true;
1471
1472 /*
1473 * If nremove is less than 1/8th memtupcount, just stop here, leaving the
1474 * "deleted" slots as NULL. This prevents us from expending O(N^2) time
1475 * repeatedly memmove-ing a large pointer array. The worst case space
1476 * wastage is pretty small, since it's just pointers and not whole tuples.
1477 */
1478 if (nremove < state->memtupcount / 8)
1479 return;
1480
1481 /*
1482 * Slide the array down and readjust pointers.
1483 *
1484 * In mergejoin's current usage, it's demonstrable that there will always
1485 * be exactly one non-removed tuple; so optimize that case.
1486 */
1487 if (nremove + 1 == state->memtupcount)
1488 state->memtuples[0] = state->memtuples[nremove];
1489 else
1490 memmove(state->memtuples, state->memtuples + nremove,
1491 (state->memtupcount - nremove) * sizeof(void *));
1492
1493 state->memtupdeleted = 0;
1494 state->memtupcount -= nremove;
1495 for (i = 0; i < state->readptrcount; i++)
1496 {
1497 if (!state->readptrs[i].eof_reached)
1498 state->readptrs[i].current -= nremove;
1499 }
1500}
#define Min(x, y)
Definition: c.h:961

References Assert, EXEC_FLAG_REWIND, FREEMEM, GetMemoryChunkSpace(), i, Min, pfree(), TSS_INMEM, and tuplestore_updatemax().

Referenced by ExecMaterialMarkPos(), and ExecWindowAgg().

◆ tuplestore_tuple_count()

int64 tuplestore_tuple_count ( Tuplestorestate state)

Definition at line 580 of file tuplestore.c.

581{
582 return state->tuples;
583}

Referenced by exec_stmt_return_query(), fetch_remote_table_info(), and SPI_register_trigger_data().

◆ tuplestore_updatemax()

static void tuplestore_updatemax ( Tuplestorestate state)
static

Definition at line 1508 of file tuplestore.c.

1509{
1510 if (state->status == TSS_INMEM)
1511 state->maxSpace = Max(state->maxSpace,
1512 state->allowedMem - state->availMem);
1513 else
1514 {
1515 state->maxSpace = Max(state->maxSpace,
1516 BufFileSize(state->myfile));
1517
1518 /*
1519 * usedDisk never gets set to false again after spilling to disk, even
1520 * if tuplestore_clear() is called and new tuples go to memory again.
1521 */
1522 state->usedDisk = true;
1523 }
1524}
int64 BufFileSize(BufFile *file)
Definition: buffile.c:866

References BufFileSize(), Max, and TSS_INMEM.

Referenced by tuplestore_clear(), tuplestore_get_stats(), tuplestore_puttuple_common(), and tuplestore_trim().

◆ writetup_heap()

static void writetup_heap ( Tuplestorestate state,
void *  tup 
)
static

Definition at line 1599 of file tuplestore.c.

1600{
1601 MinimalTuple tuple = (MinimalTuple) tup;
1602
1603 /* the part of the MinimalTuple we'll write: */
1604 char *tupbody = (char *) tuple + MINIMAL_TUPLE_DATA_OFFSET;
1605 unsigned int tupbodylen = tuple->t_len - MINIMAL_TUPLE_DATA_OFFSET;
1606
1607 /* total on-disk footprint: */
1608 unsigned int tuplen = tupbodylen + sizeof(int);
1609
1610 BufFileWrite(state->myfile, &tuplen, sizeof(tuplen));
1611 BufFileWrite(state->myfile, tupbody, tupbodylen);
1612 if (state->backward) /* need trailing length word? */
1613 BufFileWrite(state->myfile, &tuplen, sizeof(tuplen));
1614
1617}
void BufFileWrite(BufFile *file, const void *ptr, size_t size)
Definition: buffile.c:676
void heap_free_minimal_tuple(MinimalTuple mtup)
Definition: heaptuple.c:1524

References BufFileWrite(), FREEMEM, GetMemoryChunkSpace(), heap_free_minimal_tuple(), MINIMAL_TUPLE_DATA_OFFSET, and MinimalTupleData::t_len.

Referenced by tuplestore_begin_heap().