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-rw-r--r--src/backend/nodes/tidbitmap.c57
1 files changed, 24 insertions, 33 deletions
diff --git a/src/backend/nodes/tidbitmap.c b/src/backend/nodes/tidbitmap.c
index 3e0bca651f5..3d835024caa 100644
--- a/src/backend/nodes/tidbitmap.c
+++ b/src/backend/nodes/tidbitmap.c
@@ -40,7 +40,6 @@
#include <limits.h>
-#include "access/htup_details.h"
#include "common/hashfn.h"
#include "common/int.h"
#include "nodes/bitmapset.h"
@@ -49,14 +48,6 @@
#include "utils/dsa.h"
/*
- * The maximum number of tuples per page is not large (typically 256 with
- * 8K pages, or 1024 with 32K pages). So there's not much point in making
- * the per-page bitmaps variable size. We just legislate that the size
- * is this:
- */
-#define MAX_TUPLES_PER_PAGE MaxHeapTuplesPerPage
-
-/*
* When we have to switch over to lossy storage, we use a data structure
* with one bit per page, where all pages having the same number DIV
* PAGES_PER_CHUNK are aggregated into one chunk. When a chunk is present
@@ -67,7 +58,7 @@
* table, using identical data structures. (This is because the memory
* management for hashtables doesn't easily/efficiently allow space to be
* transferred easily from one hashtable to another.) Therefore it's best
- * if PAGES_PER_CHUNK is the same as MAX_TUPLES_PER_PAGE, or at least not
+ * if PAGES_PER_CHUNK is the same as TBM_MAX_TUPLES_PER_PAGE, or at least not
* too different. But we also want PAGES_PER_CHUNK to be a power of 2 to
* avoid expensive integer remainder operations. So, define it like this:
*/
@@ -79,7 +70,7 @@
#define BITNUM(x) ((x) % BITS_PER_BITMAPWORD)
/* number of active words for an exact page: */
-#define WORDS_PER_PAGE ((MAX_TUPLES_PER_PAGE - 1) / BITS_PER_BITMAPWORD + 1)
+#define WORDS_PER_PAGE ((TBM_MAX_TUPLES_PER_PAGE - 1) / BITS_PER_BITMAPWORD + 1)
/* number of active words for a lossy chunk: */
#define WORDS_PER_CHUNK ((PAGES_PER_CHUNK - 1) / BITS_PER_BITMAPWORD + 1)
@@ -181,7 +172,7 @@ struct TBMPrivateIterator
int spageptr; /* next spages index */
int schunkptr; /* next schunks index */
int schunkbit; /* next bit to check in current schunk */
- TBMIterateResult output; /* MUST BE LAST (because variable-size) */
+ TBMIterateResult output;
};
/*
@@ -222,7 +213,7 @@ struct TBMSharedIterator
PTEntryArray *ptbase; /* pagetable element array */
PTIterationArray *ptpages; /* sorted exact page index list */
PTIterationArray *ptchunks; /* sorted lossy page index list */
- TBMIterateResult output; /* MUST BE LAST (because variable-size) */
+ TBMIterateResult output;
};
/* Local function prototypes */
@@ -390,7 +381,7 @@ tbm_add_tuples(TIDBitmap *tbm, const ItemPointer tids, int ntids,
bitnum;
/* safety check to ensure we don't overrun bit array bounds */
- if (off < 1 || off > MAX_TUPLES_PER_PAGE)
+ if (off < 1 || off > TBM_MAX_TUPLES_PER_PAGE)
elog(ERROR, "tuple offset out of range: %u", off);
/*
@@ -696,9 +687,7 @@ tbm_begin_private_iterate(TIDBitmap *tbm)
* Create the TBMPrivateIterator struct, with enough trailing space to
* serve the needs of the TBMIterateResult sub-struct.
*/
- iterator = (TBMPrivateIterator *) palloc(sizeof(TBMPrivateIterator) +
- MAX_TUPLES_PER_PAGE *
- sizeof(OffsetNumber));
+ iterator = (TBMPrivateIterator *) palloc(sizeof(TBMPrivateIterator));
iterator->tbm = tbm;
/*
@@ -906,11 +895,16 @@ tbm_prepare_shared_iterate(TIDBitmap *tbm)
/*
* tbm_extract_page_tuple - extract the tuple offsets from a page
*
- * The extracted offsets are stored into TBMIterateResult.
+ * Returns the number of offsets it filled in if <= max_offsets. Otherwise,
+ * fills in as many offsets as fit and returns the total number of offsets in
+ * the page.
*/
-static inline int
-tbm_extract_page_tuple(PagetableEntry *page, TBMIterateResult *output)
+int
+tbm_extract_page_tuple(TBMIterateResult *iteritem,
+ OffsetNumber *offsets,
+ uint32 max_offsets)
{
+ PagetableEntry *page = iteritem->internal_page;
int wordnum;
int ntuples = 0;
@@ -925,7 +919,11 @@ tbm_extract_page_tuple(PagetableEntry *page, TBMIterateResult *output)
while (w != 0)
{
if (w & 1)
- output->offsets[ntuples++] = (OffsetNumber) off;
+ {
+ if (ntuples < max_offsets)
+ offsets[ntuples] = (OffsetNumber) off;
+ ntuples++;
+ }
off++;
w >>= 1;
}
@@ -1012,9 +1010,9 @@ tbm_private_iterate(TBMPrivateIterator *iterator)
{
/* Return a lossy page indicator from the chunk */
output->blockno = chunk_blockno;
- output->ntuples = -1;
output->lossy = true;
output->recheck = true;
+ output->internal_page = NULL;
iterator->schunkbit++;
return output;
}
@@ -1023,7 +1021,6 @@ tbm_private_iterate(TBMPrivateIterator *iterator)
if (iterator->spageptr < tbm->npages)
{
PagetableEntry *page;
- int ntuples;
/* In TBM_ONE_PAGE state, we don't allocate an spages[] array */
if (tbm->status == TBM_ONE_PAGE)
@@ -1031,10 +1028,8 @@ tbm_private_iterate(TBMPrivateIterator *iterator)
else
page = tbm->spages[iterator->spageptr];
- /* scan bitmap to extract individual offset numbers */
- ntuples = tbm_extract_page_tuple(page, output);
+ output->internal_page = page;
output->blockno = page->blockno;
- output->ntuples = ntuples;
output->lossy = false;
output->recheck = page->recheck;
iterator->spageptr++;
@@ -1107,9 +1102,9 @@ tbm_shared_iterate(TBMSharedIterator *iterator)
{
/* Return a lossy page indicator from the chunk */
output->blockno = chunk_blockno;
- output->ntuples = -1;
output->lossy = true;
output->recheck = true;
+ output->internal_page = NULL;
istate->schunkbit++;
LWLockRelease(&istate->lock);
@@ -1120,12 +1115,9 @@ tbm_shared_iterate(TBMSharedIterator *iterator)
if (istate->spageptr < istate->npages)
{
PagetableEntry *page = &ptbase[idxpages[istate->spageptr]];
- int ntuples;
- /* scan bitmap to extract individual offset numbers */
- ntuples = tbm_extract_page_tuple(page, output);
+ output->internal_page = page;
output->blockno = page->blockno;
- output->ntuples = ntuples;
output->lossy = false;
output->recheck = page->recheck;
istate->spageptr++;
@@ -1473,8 +1465,7 @@ tbm_attach_shared_iterate(dsa_area *dsa, dsa_pointer dp)
* Create the TBMSharedIterator struct, with enough trailing space to
* serve the needs of the TBMIterateResult sub-struct.
*/
- iterator = (TBMSharedIterator *) palloc0(sizeof(TBMSharedIterator) +
- MAX_TUPLES_PER_PAGE * sizeof(OffsetNumber));
+ iterator = (TBMSharedIterator *) palloc0(sizeof(TBMSharedIterator));
istate = (TBMSharedIteratorState *) dsa_get_address(dsa, dp);
generated by cgit v1.2.3 (git 2.46.0) at 2025-08-09 20:09:17 +0000