database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-08-31 17:02:12 +03:00
Code Activity

Change ginMergeItemPointers to return a palloc'd array.

Browse Source 
That seems nicer than making it the caller's responsibility to pass a
suitable-sized array. All the callers were just palloc'ing an array anyway.
This commit is contained in:
Heikki Linnakangas
2014-03-24 18:40:26 +02:00
parent cf5d38f4b9
commit bb42e21be2
4 changed files with 30 additions and 32 deletions
Download Patch File Download Diff File Expand all files Collapse all files

40
src/backend/access/gin/ginpostinglist.c
View File

@@ -346,20 +346,18 @@ ginPostingListDecodeAllSegmentsToTbm(GinPostingList *ptr, int len,
/*
* Merge two ordered arrays of itempointers, eliminating any duplicates.
* Returns the number of items in the result.
* Caller is responsible that there is enough space at *dst.
*
* It's OK if 'dst' overlaps with the *beginning* of one of the arguments.
* Returns a palloc'd array, and *nmerged is set to the number of items in
* the result, after eliminating duplicates.
*/
int
ginMergeItemPointers(ItemPointerData *dst,
ItemPointerData *a, uint32 na,
ItemPointerData *b, uint32 nb)
ItemPointer
ginMergeItemPointers(ItemPointerData *a, uint32 na,
ItemPointerData *b, uint32 nb,
int *nmerged)
{
ItemPointerData *dptr = dst;
ItemPointerData *aptr = a,
*bptr = b;
int result;
ItemPointerData *dst;
dst = (ItemPointer) palloc((na + nb) * sizeof(ItemPointerData));
/*
* If the argument arrays don't overlap, we can just append them to
@@ -367,18 +365,22 @@ ginMergeItemPointers(ItemPointerData *dst,
*/
if (na == 0 || nb == 0 || ginCompareItemPointers(&a[na - 1], &b[0]) < 0)
{
memmove(dst, a, na * sizeof(ItemPointerData));
memmove(&dst[na], b, nb * sizeof(ItemPointerData));
result = na + nb;
memcpy(dst, a, na * sizeof(ItemPointerData));
memcpy(&dst[na], b, nb * sizeof(ItemPointerData));
*nmerged = na + nb;
}
else if (ginCompareItemPointers(&b[nb - 1], &a[0]) < 0)
{
memmove(dst, b, nb * sizeof(ItemPointerData));
memmove(&dst[nb], a, na * sizeof(ItemPointerData));
result = na + nb;
memcpy(dst, b, nb * sizeof(ItemPointerData));
memcpy(&dst[nb], a, na * sizeof(ItemPointerData));
*nmerged = na + nb;
}
else
{
ItemPointerData *dptr = dst;
ItemPointerData *aptr = a;
ItemPointerData *bptr = b;
while (aptr - a < na && bptr - b < nb)
{
int cmp = ginCompareItemPointers(aptr, bptr);
@@ -401,8 +403,8 @@ ginMergeItemPointers(ItemPointerData *dst,
while (bptr - b < nb)
*dptr++ = *bptr++;
result = dptr - dst;
*nmerged = dptr - dst;
}
return result;
return dst;
}