From 943060f91d3edcb1c94837a09dfb5566bf2daded Mon Sep 17 00:00:00 2001 From: Thomas Munro Date: Mon, 2 Mar 2026 04:15:05 +1300 Subject: [PATCH v2 09/19] Use stack buffer in some access method code. Mechanical changes including: * temporary strings * temporary datum, null, key lists etc * WAL construction --- src/backend/access/brin/brin_tuple.c | 19 +++++++++------ src/backend/access/common/heaptuple.c | 21 ++++++++++------- src/backend/access/gin/ginscan.c | 7 ++++-- src/backend/access/hash/hashfunc.c | 12 ++++++---- src/backend/access/heap/heapam.c | 12 ++++++---- src/backend/access/heap/heapam_handler.c | 11 +++++---- src/backend/access/index/genam.c | 23 ++++++++++++------- src/backend/access/nbtree/nbtpreprocesskeys.c | 23 +++++++++++-------- src/backend/access/nbtree/nbtxlog.c | 9 +++++--- 9 files changed, 87 insertions(+), 50 deletions(-) diff --git a/src/backend/access/brin/brin_tuple.c b/src/backend/access/brin/brin_tuple.c index 69c233c62eb..13ff1d3f5d6 100644 --- a/src/backend/access/brin/brin_tuple.c +++ b/src/backend/access/brin/brin_tuple.c @@ -40,6 +40,7 @@ #include "access/tupmacs.h" #include "utils/datum.h" #include "utils/memutils.h" +#include "utils/stack_buffer.h" /* @@ -117,14 +118,16 @@ brin_form_tuple(BrinDesc *brdesc, BlockNumber blkno, BrinMemTuple *tuple, int nuntoasted = 0; #endif + DECLARE_STACK_BUFFER(); + Assert(brdesc->bd_totalstored > 0); - values = palloc_array(Datum, brdesc->bd_totalstored); - nulls = palloc0_array(bool, brdesc->bd_totalstored); - phony_nullbitmap = palloc_array(bits8, BITMAPLEN(brdesc->bd_totalstored)); + values = stack_buffer_alloc_array(Datum, brdesc->bd_totalstored); + nulls = stack_buffer_alloc0_array(bool, brdesc->bd_totalstored); + phony_nullbitmap = stack_buffer_alloc_array(bits8, BITMAPLEN(brdesc->bd_totalstored)); #ifdef TOAST_INDEX_HACK - untoasted_values = palloc_array(Datum, brdesc->bd_totalstored); + untoasted_values = stack_buffer_alloc_array(Datum, brdesc->bd_totalstored); #endif /* @@ -307,13 +310,15 @@ brin_form_tuple(BrinDesc *brdesc, BlockNumber blkno, BrinMemTuple *tuple, phony_nullbitmap); /* done with these */ - pfree(values); - pfree(nulls); - pfree(phony_nullbitmap); + stack_buffer_free(values); + stack_buffer_free(nulls); + stack_buffer_free(phony_nullbitmap); #ifdef TOAST_INDEX_HACK for (i = 0; i < nuntoasted; i++) pfree(DatumGetPointer(untoasted_values[i])); + + stack_buffer_free(untoasted_values); #endif /* diff --git a/src/backend/access/common/heaptuple.c b/src/backend/access/common/heaptuple.c index 11bec20e82e..12f820056ba 100644 --- a/src/backend/access/common/heaptuple.c +++ b/src/backend/access/common/heaptuple.c @@ -65,6 +65,7 @@ #include "utils/expandeddatum.h" #include "utils/hsearch.h" #include "utils/memutils.h" +#include "utils/stack_buffer.h" /* @@ -1219,6 +1220,8 @@ heap_modify_tuple(HeapTuple tuple, bool *isnull; HeapTuple newTuple; + DECLARE_STACK_BUFFER(); + /* * allocate and fill values and isnull arrays from either the tuple or the * repl information, as appropriate. @@ -1230,8 +1233,8 @@ heap_modify_tuple(HeapTuple tuple, * O(N^2) if there are many non-replaced columns, so it seems better to * err on the side of linear cost. */ - values = palloc_array(Datum, numberOfAttributes); - isnull = palloc_array(bool, numberOfAttributes); + values = stack_buffer_alloc_array(Datum, numberOfAttributes); + isnull = stack_buffer_alloc_array(bool, numberOfAttributes); heap_deform_tuple(tuple, tupleDesc, values, isnull); @@ -1249,8 +1252,8 @@ heap_modify_tuple(HeapTuple tuple, */ newTuple = heap_form_tuple(tupleDesc, values, isnull); - pfree(values); - pfree(isnull); + stack_buffer_free(values); + stack_buffer_free(isnull); /* * copy the identification info of the old tuple: t_ctid, t_self @@ -1288,12 +1291,14 @@ heap_modify_tuple_by_cols(HeapTuple tuple, HeapTuple newTuple; int i; + DECLARE_STACK_BUFFER(); + /* * allocate and fill values and isnull arrays from the tuple, then replace * selected columns from the input arrays. */ - values = palloc_array(Datum, numberOfAttributes); - isnull = palloc_array(bool, numberOfAttributes); + values = stack_buffer_alloc_array(Datum, numberOfAttributes); + isnull = stack_buffer_alloc_array(bool, numberOfAttributes); heap_deform_tuple(tuple, tupleDesc, values, isnull); @@ -1312,8 +1317,8 @@ heap_modify_tuple_by_cols(HeapTuple tuple, */ newTuple = heap_form_tuple(tupleDesc, values, isnull); - pfree(values); - pfree(isnull); + stack_buffer_free(values); + stack_buffer_free(isnull); /* * copy the identification info of the old tuple: t_ctid, t_self diff --git a/src/backend/access/gin/ginscan.c b/src/backend/access/gin/ginscan.c index fb929761ab7..6d3d2737080 100644 --- a/src/backend/access/gin/ginscan.c +++ b/src/backend/access/gin/ginscan.c @@ -20,6 +20,7 @@ #include "pgstat.h" #include "utils/memutils.h" #include "utils/rel.h" +#include "utils/stack_buffer.h" IndexScanDesc @@ -420,10 +421,12 @@ ginNewScanKey(IndexScanDesc scan) int iNormalKey; int iExcludeOnly; + DECLARE_STACK_BUFFER(); + /* We'd better have made at least one normal key */ Assert(numExcludeOnly < so->nkeys); /* Make a temporary array to hold the re-ordered scan keys */ - tmpkeys = (GinScanKey) palloc(so->nkeys * sizeof(GinScanKeyData)); + tmpkeys = stack_buffer_alloc_array(GinScanKeyData, so->nkeys); /* Re-order the keys ... */ iNormalKey = 0; iExcludeOnly = so->nkeys - numExcludeOnly; @@ -446,7 +449,7 @@ ginNewScanKey(IndexScanDesc scan) Assert(iExcludeOnly == so->nkeys); /* ... and copy them back to so->keys[] */ memcpy(so->keys, tmpkeys, so->nkeys * sizeof(GinScanKeyData)); - pfree(tmpkeys); + stack_buffer_free(tmpkeys); } /* diff --git a/src/backend/access/hash/hashfunc.c b/src/backend/access/hash/hashfunc.c index 575342a21b6..cda9ce28780 100644 --- a/src/backend/access/hash/hashfunc.c +++ b/src/backend/access/hash/hashfunc.c @@ -31,6 +31,7 @@ #include "utils/float.h" #include "utils/fmgrprotos.h" #include "utils/pg_locale.h" +#include "utils/stack_buffer.h" #include "varatt.h" /* @@ -295,9 +296,10 @@ hashtext(PG_FUNCTION_ARGS) const char *keydata = VARDATA_ANY(key); size_t keylen = VARSIZE_ANY_EXHDR(key); + DECLARE_STACK_BUFFER(); bsize = pg_strnxfrm(NULL, 0, keydata, keylen, mylocale); - buf = palloc(bsize + 1); + buf = stack_buffer_alloc(bsize + 1); rsize = pg_strnxfrm(buf, bsize + 1, keydata, keylen, mylocale); @@ -312,7 +314,7 @@ hashtext(PG_FUNCTION_ARGS) */ result = hash_any((uint8_t *) buf, bsize + 1); - pfree(buf); + stack_buffer_free(buf); } /* Avoid leaking memory for toasted inputs */ @@ -351,8 +353,10 @@ hashtextextended(PG_FUNCTION_ARGS) const char *keydata = VARDATA_ANY(key); size_t keylen = VARSIZE_ANY_EXHDR(key); + DECLARE_STACK_BUFFER(); + bsize = pg_strnxfrm(NULL, 0, keydata, keylen, mylocale); - buf = palloc(bsize + 1); + buf = stack_buffer_alloc(bsize + 1); rsize = pg_strnxfrm(buf, bsize + 1, keydata, keylen, mylocale); @@ -368,7 +372,7 @@ hashtextextended(PG_FUNCTION_ARGS) result = hash_any_extended((uint8_t *) buf, bsize + 1, PG_GETARG_INT64(1)); - pfree(buf); + stack_buffer_free(buf); } PG_FREE_IF_COPY(key, 0); diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c index 8f1c11a9350..13171df183c 100644 --- a/src/backend/access/heap/heapam.c +++ b/src/backend/access/heap/heapam.c @@ -53,6 +53,7 @@ #include "utils/injection_point.h" #include "utils/inval.h" #include "utils/spccache.h" +#include "utils/stack_buffer.h" #include "utils/syscache.h" @@ -8768,11 +8769,13 @@ bottomup_sort_and_shrink(TM_IndexDeleteOp *delstate) int ncopied = 0; int nblocksfavorable = 0; + DECLARE_STACK_BUFFER(); + Assert(delstate->bottomup); Assert(delstate->ndeltids > 0); /* Calculate per-heap-block count of TIDs */ - blockgroups = palloc_array(IndexDeleteCounts, delstate->ndeltids); + blockgroups = stack_buffer_alloc_array(IndexDeleteCounts, delstate->ndeltids); for (int i = 0; i < delstate->ndeltids; i++) { TM_IndexDelete *ideltid = &delstate->deltids[i]; @@ -8845,7 +8848,8 @@ bottomup_sort_and_shrink(TM_IndexDeleteOp *delstate) /* Sort groups and rearrange caller's deltids array */ qsort(blockgroups, nblockgroups, sizeof(IndexDeleteCounts), bottomup_sort_and_shrink_cmp); - reordereddeltids = palloc(delstate->ndeltids * sizeof(TM_IndexDelete)); + reordereddeltids = stack_buffer_alloc_array(TM_IndexDelete, + delstate->ndeltids); nblockgroups = Min(BOTTOMUP_MAX_NBLOCKS, nblockgroups); /* Determine number of favorable blocks at the start of final deltids */ @@ -8867,8 +8871,8 @@ bottomup_sort_and_shrink(TM_IndexDeleteOp *delstate) sizeof(TM_IndexDelete) * ncopied); delstate->ndeltids = ncopied; - pfree(reordereddeltids); - pfree(blockgroups); + stack_buffer_free(reordereddeltids); + stack_buffer_free(blockgroups); return nblocksfavorable; } diff --git a/src/backend/access/heap/heapam_handler.c b/src/backend/access/heap/heapam_handler.c index 5137d2510ea..cfb06ab82ac 100644 --- a/src/backend/access/heap/heapam_handler.c +++ b/src/backend/access/heap/heapam_handler.c @@ -45,6 +45,7 @@ #include "storage/smgr.h" #include "utils/builtins.h" #include "utils/rel.h" +#include "utils/stack_buffer.h" static void reform_and_rewrite_tuple(HeapTuple tuple, Relation OldHeap, Relation NewHeap, @@ -706,6 +707,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap, BufferHeapTupleTableSlot *hslot; BlockNumber prev_cblock = InvalidBlockNumber; + DECLARE_STACK_BUFFER(); + /* Remember if it's a system catalog */ is_system_catalog = IsSystemRelation(OldHeap); @@ -717,8 +720,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap, /* Preallocate values/isnull arrays */ natts = newTupDesc->natts; - values = palloc_array(Datum, natts); - isnull = palloc_array(bool, natts); + values = stack_buffer_alloc_array(Datum, natts); + isnull = stack_buffer_alloc_array(bool, natts); /* Initialize the rewrite operation */ rwstate = begin_heap_rewrite(OldHeap, NewHeap, OldestXmin, *xid_cutoff, @@ -1002,8 +1005,8 @@ heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap, end_heap_rewrite(rwstate); /* Clean up */ - pfree(values); - pfree(isnull); + stack_buffer_free(values); + stack_buffer_free(isnull); } /* diff --git a/src/backend/access/index/genam.c b/src/backend/access/index/genam.c index 5e89b86a62c..30df0b8819b 100644 --- a/src/backend/access/index/genam.c +++ b/src/backend/access/index/genam.c @@ -36,6 +36,7 @@ #include "utils/rls.h" #include "utils/ruleutils.h" #include "utils/snapmgr.h" +#include "utils/stack_buffer.h" /* ---------------------------------------------------------------- @@ -303,6 +304,8 @@ index_compute_xid_horizon_for_tuples(Relation irel, Page ipage = BufferGetPage(ibuf); IndexTuple itup; + DECLARE_STACK_BUFFER(); + Assert(nitems > 0); delstate.irel = irel; @@ -310,8 +313,8 @@ index_compute_xid_horizon_for_tuples(Relation irel, delstate.bottomup = false; delstate.bottomupfreespace = 0; delstate.ndeltids = 0; - delstate.deltids = palloc_array(TM_IndexDelete, nitems); - delstate.status = palloc_array(TM_IndexStatus, nitems); + delstate.deltids = stack_buffer_alloc_array(TM_IndexDelete, nitems); + delstate.status = stack_buffer_alloc_array(TM_IndexStatus, nitems); /* identify what the index tuples about to be deleted point to */ for (int i = 0; i < nitems; i++) @@ -340,8 +343,8 @@ index_compute_xid_horizon_for_tuples(Relation irel, /* assert tableam agrees that all items are deletable */ Assert(delstate.ndeltids == nitems); - pfree(delstate.deltids); - pfree(delstate.status); + stack_buffer_free(delstate.deltids); + stack_buffer_free(delstate.status); return snapshotConflictHorizon; } @@ -433,7 +436,9 @@ systable_beginscan(Relation heapRelation, int i; ScanKey idxkey; - idxkey = palloc_array(ScanKeyData, nkeys); + DECLARE_STACK_BUFFER(); + + idxkey = stack_buffer_alloc_array(ScanKeyData, nkeys); /* Convert attribute numbers to be index column numbers. */ for (i = 0; i < nkeys; i++) @@ -459,7 +464,7 @@ systable_beginscan(Relation heapRelation, index_rescan(sysscan->iscan, idxkey, nkeys, NULL, 0); sysscan->scan = NULL; - pfree(idxkey); + stack_buffer_free(idxkey); } else { @@ -656,6 +661,8 @@ systable_beginscan_ordered(Relation heapRelation, int i; ScanKey idxkey; + DECLARE_STACK_BUFFER(); + /* REINDEX can probably be a hard error here ... */ if (ReindexIsProcessingIndex(RelationGetRelid(indexRelation))) ereport(ERROR, @@ -686,7 +693,7 @@ systable_beginscan_ordered(Relation heapRelation, sysscan->snapshot = NULL; } - idxkey = palloc_array(ScanKeyData, nkeys); + idxkey = stack_buffer_alloc_array(ScanKeyData, nkeys); /* Convert attribute numbers to be index column numbers. */ for (i = 0; i < nkeys; i++) @@ -720,7 +727,7 @@ systable_beginscan_ordered(Relation heapRelation, index_rescan(sysscan->iscan, idxkey, nkeys, NULL, 0); sysscan->scan = NULL; - pfree(idxkey); + stack_buffer_free(idxkey); return sysscan; } diff --git a/src/backend/access/nbtree/nbtpreprocesskeys.c b/src/backend/access/nbtree/nbtpreprocesskeys.c index 39c0a5d610f..b62e6892345 100644 --- a/src/backend/access/nbtree/nbtpreprocesskeys.c +++ b/src/backend/access/nbtree/nbtpreprocesskeys.c @@ -23,6 +23,7 @@ #include "utils/lsyscache.h" #include "utils/memutils.h" #include "utils/rel.h" +#include "utils/stack_buffer.h" typedef struct BTScanKeyPreproc { @@ -1557,6 +1558,8 @@ _bt_unmark_keys(IndexScanDesc scan, int *keyDataMap) haveReqForward, haveReqBackward; + DECLARE_STACK_BUFFER(); + /* * Do an initial pass over so->keyData[] that determines which keys to * keep as required. We expect so->keyData[] to still be in attribute @@ -1568,7 +1571,7 @@ _bt_unmark_keys(IndexScanDesc scan, int *keyDataMap) * Any requiredness markings that we might leave on later keys/attributes * are predicated on there being required = keys on all prior columns. */ - unmarkikey = palloc0(so->numberOfKeys * sizeof(bool)); + unmarkikey = stack_buffer_alloc0_array(bool, so->numberOfKeys); nunmark = 0; /* Set things up for first key's attribute */ @@ -1653,14 +1656,14 @@ _bt_unmark_keys(IndexScanDesc scan, int *keyDataMap) * Next, allocate temp arrays: one for required keys that'll remain * required, the other for all remaining keys */ - unmarkKeys = palloc(nunmark * sizeof(ScanKeyData)); - keepKeys = palloc((so->numberOfKeys - nunmark) * sizeof(ScanKeyData)); + unmarkKeys = stack_buffer_alloc_array(ScanKeyData, nunmark); + keepKeys = stack_buffer_alloc_array(ScanKeyData, so->numberOfKeys - nunmark); nunmarked = 0; nkept = 0; if (so->numArrayKeys) { - unmarkOrderProcs = palloc(nunmark * sizeof(FmgrInfo)); - keepOrderProcs = palloc((so->numberOfKeys - nunmark) * sizeof(FmgrInfo)); + unmarkOrderProcs = stack_buffer_alloc_array(FmgrInfo, nunmark); + keepOrderProcs = stack_buffer_alloc_array(FmgrInfo, so->numberOfKeys - nunmark); } /* @@ -1751,9 +1754,9 @@ _bt_unmark_keys(IndexScanDesc scan, int *keyDataMap) memcpy(so->keyData + nkept, unmarkKeys, sizeof(ScanKeyData) * nunmarked); /* Done with temp arrays */ - pfree(unmarkikey); - pfree(keepKeys); - pfree(unmarkKeys); + stack_buffer_free(unmarkikey); + stack_buffer_free(keepKeys); + stack_buffer_free(unmarkKeys); /* * Now copy so->orderProcs[] temp entries needed by scans with = array @@ -1781,8 +1784,8 @@ _bt_unmark_keys(IndexScanDesc scan, int *keyDataMap) _bt_reorder_array_cmp); /* Done with temp arrays */ - pfree(unmarkOrderProcs); - pfree(keepOrderProcs); + stack_buffer_free(unmarkOrderProcs); + stack_buffer_free(keepOrderProcs); } } diff --git a/src/backend/access/nbtree/nbtxlog.c b/src/backend/access/nbtree/nbtxlog.c index dff7d286fc8..14bd0fd2fd3 100644 --- a/src/backend/access/nbtree/nbtxlog.c +++ b/src/backend/access/nbtree/nbtxlog.c @@ -21,6 +21,7 @@ #include "access/xlogutils.h" #include "storage/standby.h" #include "utils/memutils.h" +#include "utils/stack_buffer.h" static MemoryContext opCtx; /* working memory for operations */ @@ -551,13 +552,15 @@ btree_xlog_updates(Page page, OffsetNumber *updatedoffsets, ItemId itemid; Size itemsz; + DECLARE_STACK_BUFFER(); + for (int i = 0; i < nupdated; i++) { itemid = PageGetItemId(page, updatedoffsets[i]); origtuple = (IndexTuple) PageGetItem(page, itemid); - vacposting = palloc(offsetof(BTVacuumPostingData, deletetids) + - updates->ndeletedtids * sizeof(uint16)); + vacposting = stack_buffer_alloc(offsetof(BTVacuumPostingData, deletetids) + + updates->ndeletedtids * sizeof(uint16)); vacposting->updatedoffset = updatedoffsets[i]; vacposting->itup = origtuple; vacposting->ndeletedtids = updates->ndeletedtids; @@ -573,7 +576,7 @@ btree_xlog_updates(Page page, OffsetNumber *updatedoffsets, elog(PANIC, "failed to update partially dead item"); pfree(vacposting->itup); - pfree(vacposting); + stack_buffer_free(vacposting); /* advance to next xl_btree_update from array */ updates = (xl_btree_update *) -- 2.53.0