currentItemData refactoring

This has been saved for the 8.3 release:

http://momjian.postgresql.org/cgi-bin/pgpatches_hold

---------------------------------------------------------------------------

Heikki Linnakangas wrote:

Here's a patch to remove currentItemData & currentMarkpos from
IndexScanDesc, and add equivalent fields in access method specific
opaque structs for those access methods that need them. That makes the
index am API cleaner.

--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com

---------------------------(end of broadcast)---------------------------
TIP 1: if posting/reading through Usenet, please send an appropriate
subscribe-nomail command to majordomo@postgresql.org so that your
message can get through to the mailing list cleanly

--
Bruce Momjian bruce@momjian.us
EnterpriseDB http://www.enterprisedb.com

+ If your life is a hard drive, Christ can be your backup. +

Patch applied by Neil. Thanks.

---------------------------------------------------------------------------

Heikki Linnakangas wrote:

Here's a patch to remove currentItemData & currentMarkpos from
IndexScanDesc, and add equivalent fields in access method specific
opaque structs for those access methods that need them. That makes the
index am API cleaner.

--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com

[ text/x-patch is unsupported, treating like TEXT/PLAIN ]

Index: src/backend/access/gist/gistget.c
===================================================================
RCS file: /home/hlinnaka/pgcvsrepository/pgsql/src/backend/access/gist/gistget.c,v
retrieving revision 1.60
diff -c -r1.60 gistget.c
*** src/backend/access/gist/gistget.c	14 Jul 2006 14:52:16 -0000	1.60
--- src/backend/access/gist/gistget.c	12 Sep 2006 15:37:48 -0000
***************
*** 106,113 ****
* If we have produced an index tuple in the past and the executor has
* informed us we need to mark it as "killed", do so now.
*/
! 	if (scan->kill_prior_tuple && ItemPointerIsValid(&(scan->currentItemData)))
! 		killtuple(scan->indexRelation, so, &(scan->currentItemData));

/*
* Get the next tuple that matches the search key. If asked to skip killed
--- 106,113 ----
* If we have produced an index tuple in the past and the executor has
* informed us we need to mark it as "killed", do so now.
*/
! 	if (scan->kill_prior_tuple && ItemPointerIsValid(&(so->curpos)))
! 		killtuple(scan->indexRelation, so, &(so->curpos));

/*
* Get the next tuple that matches the search key. If asked to skip killed
***************
*** 151,157 ****

so = (GISTScanOpaque) scan->opaque;

! 	if (ItemPointerIsValid(&scan->currentItemData) == false)
{
/* Being asked to fetch the first entry, so start at the root */
Assert(so->curbuf == InvalidBuffer);
--- 151,157 ----

so = (GISTScanOpaque) scan->opaque;

! if (ItemPointerIsValid(&so->curpos) == false)
{
/* Being asked to fetch the first entry, so start at the root */
Assert(so->curbuf == InvalidBuffer);
***************
*** 226,232 ****
}

if (!GistPageIsLeaf(p) || resetoffset ||
! 			!ItemPointerIsValid(&scan->currentItemData))
{
if (ScanDirectionIsBackward(dir))
n = PageGetMaxOffsetNumber(p);
--- 226,232 ----
}

if (!GistPageIsLeaf(p) || resetoffset ||
! !ItemPointerIsValid(&so->curpos))
{
if (ScanDirectionIsBackward(dir))
n = PageGetMaxOffsetNumber(p);
***************
*** 235,241 ****
}
else
{
! n = ItemPointerGetOffsetNumber(&(scan->currentItemData));

if (ScanDirectionIsBackward(dir))
n = OffsetNumberPrev(n);
--- 235,241 ----
}
else
{
! 			n = ItemPointerGetOffsetNumber(&(so->curpos));

if (ScanDirectionIsBackward(dir))
n = OffsetNumberPrev(n);
***************
*** 285,291 ****
* we can efficiently resume the index scan later.
*/

! ItemPointerSet(&(scan->currentItemData),
BufferGetBlockNumber(so->curbuf), n);

if (!(ignore_killed_tuples && ItemIdDeleted(PageGetItemId(p, n))))
--- 285,291 ----
* we can efficiently resume the index scan later.
*/

! ItemPointerSet(&(so->curpos),
BufferGetBlockNumber(so->curbuf), n);

if (!(ignore_killed_tuples && ItemIdDeleted(PageGetItemId(p, n))))
Index: src/backend/access/gist/gistscan.c
===================================================================
RCS file: /home/hlinnaka/pgcvsrepository/pgsql/src/backend/access/gist/gistscan.c,v
retrieving revision 1.64
diff -c -r1.64 gistscan.c
*** src/backend/access/gist/gistscan.c	14 Jul 2006 14:52:16 -0000	1.64
--- src/backend/access/gist/gistscan.c	12 Sep 2006 15:38:52 -0000
***************
*** 42,53 ****
GISTScanOpaque so;
int			i;

- 	/*
- 	 * Clear all the pointers.
- 	 */
- 	ItemPointerSetInvalid(&scan->currentItemData);
- 	ItemPointerSetInvalid(&scan->currentMarkData);
- 
so = (GISTScanOpaque) scan->opaque;
if (so != NULL)
{
--- 42,47 ----
***************
*** 82,87 ****
--- 76,88 ----
scan->opaque = so;
}

+ 
+ 	/*
+ 	 * Clear all the pointers.
+ 	 */
+ 	ItemPointerSetInvalid(&so->curpos);
+ 	ItemPointerSetInvalid(&so->markpos);
+ 
/* Update scan key, if a new one is given */
if (key && scan->numberOfKeys > 0)
{
***************
*** 111,117 ****
*n,
*tmp;

! 	scan->currentMarkData = scan->currentItemData;
so = (GISTScanOpaque) scan->opaque;
if (so->flags & GS_CURBEFORE)
so->flags |= GS_MRKBEFORE;
--- 112,118 ----
*n,
*tmp;

! so->markpos = so->curpos;
so = (GISTScanOpaque) scan->opaque;
if (so->flags & GS_CURBEFORE)
so->flags |= GS_MRKBEFORE;
***************
*** 160,166 ****
*n,
*tmp;

! 	scan->currentItemData = scan->currentMarkData;
so = (GISTScanOpaque) scan->opaque;
if (so->flags & GS_MRKBEFORE)
so->flags |= GS_CURBEFORE;
--- 161,167 ----
*n,
*tmp;

! 	so->curpos = so->markpos;
so = (GISTScanOpaque) scan->opaque;
if (so->flags & GS_MRKBEFORE)
so->flags |= GS_CURBEFORE;
Index: src/backend/access/hash/hash.c
===================================================================
RCS file: /home/hlinnaka/pgcvsrepository/pgsql/src/backend/access/hash/hash.c,v
retrieving revision 1.91
diff -c -r1.91 hash.c
*** src/backend/access/hash/hash.c	14 Jul 2006 14:52:17 -0000	1.91
--- src/backend/access/hash/hash.c	12 Sep 2006 15:45:32 -0000
***************
*** 185,191 ****
* appropriate direction.  If we haven't done so yet, we call a routine to
* get the first item in the scan.
*/
! 	if (ItemPointerIsValid(&(scan->currentItemData)))
{
/*
* Check to see if we should kill the previously-fetched tuple.
--- 185,191 ----
* appropriate direction.  If we haven't done so yet, we call a routine to
* get the first item in the scan.
*/
! 	if (ItemPointerIsValid(&(so->hashso_curpos)))
{
/*
* Check to see if we should kill the previously-fetched tuple.
***************
*** 195,201 ****
/*
* Yes, so mark it by setting the LP_DELETE bit in the item flags.
*/
! 			offnum = ItemPointerGetOffsetNumber(&(scan->currentItemData));
page = BufferGetPage(so->hashso_curbuf);
PageGetItemId(page, offnum)->lp_flags |= LP_DELETE;

--- 195,201 ----
/*
* Yes, so mark it by setting the LP_DELETE bit in the item flags.
*/
! 			offnum = ItemPointerGetOffsetNumber(&(so->hashso_curpos));
page = BufferGetPage(so->hashso_curbuf);
PageGetItemId(page, offnum)->lp_flags |= LP_DELETE;

***************
*** 222,228 ****
{
while (res)
{
! 			offnum = ItemPointerGetOffsetNumber(&(scan->currentItemData));
page = BufferGetPage(so->hashso_curbuf);
if (!ItemIdDeleted(PageGetItemId(page, offnum)))
break;
--- 222,228 ----
{
while (res)
{
! 			offnum = ItemPointerGetOffsetNumber(&(so->hashso_curpos));
page = BufferGetPage(so->hashso_curbuf);
if (!ItemIdDeleted(PageGetItemId(page, offnum)))
break;
***************
*** 269,275 ****
/*
* Start scan, or advance to next tuple.
*/
! 		if (ItemPointerIsValid(&(scan->currentItemData)))
res = _hash_next(scan, ForwardScanDirection);
else
res = _hash_first(scan, ForwardScanDirection);
--- 269,275 ----
/*
* Start scan, or advance to next tuple.
*/
! 		if (ItemPointerIsValid(&(so->hashso_curpos)))
res = _hash_next(scan, ForwardScanDirection);
else
res = _hash_first(scan, ForwardScanDirection);
***************
*** 284,290 ****
Page		page;
OffsetNumber offnum;

! 				offnum = ItemPointerGetOffsetNumber(&(scan->currentItemData));
page = BufferGetPage(so->hashso_curbuf);
if (!ItemIdDeleted(PageGetItemId(page, offnum)))
break;
--- 284,290 ----
Page		page;
OffsetNumber offnum;

! 				offnum = ItemPointerGetOffsetNumber(&(so->hashso_curpos));
page = BufferGetPage(so->hashso_curbuf);
if (!ItemIdDeleted(PageGetItemId(page, offnum)))
break;
***************
*** 326,331 ****
--- 326,335 ----
so->hashso_bucket_blkno = 0;
so->hashso_curbuf = so->hashso_mrkbuf = InvalidBuffer;
scan->opaque = so;
+ 	/* set positions invalid (this will cause _hash_first call) */
+ 	ItemPointerSetInvalid(&(so->hashso_curpos));
+ 	ItemPointerSetInvalid(&(so->hashso_mrkpos));
+ 

/* register scan in case we change pages it's using */
_hash_regscan(scan);
***************
*** 360,370 ****
if (so->hashso_bucket_blkno)
_hash_droplock(rel, so->hashso_bucket_blkno, HASH_SHARE);
so->hashso_bucket_blkno = 0;
- }

! /* set positions invalid (this will cause _hash_first call) */
! ItemPointerSetInvalid(&(scan->currentItemData));
! ItemPointerSetInvalid(&(scan->currentMarkData));

/* Update scan key, if a new one is given */
if (scankey && scan->numberOfKeys > 0)
--- 364,374 ----
if (so->hashso_bucket_blkno)
_hash_droplock(rel, so->hashso_bucket_blkno, HASH_SHARE);
so->hashso_bucket_blkno = 0;

! /* set positions invalid (this will cause _hash_first call) */
! ItemPointerSetInvalid(&(so->hashso_curpos));
! ItemPointerSetInvalid(&(so->hashso_mrkpos));
! }

/* Update scan key, if a new one is given */
if (scankey && scan->numberOfKeys > 0)
***************
*** 406,415 ****
_hash_droplock(rel, so->hashso_bucket_blkno, HASH_SHARE);
so->hashso_bucket_blkno = 0;

- /* be tidy */
- ItemPointerSetInvalid(&(scan->currentItemData));
- ItemPointerSetInvalid(&(scan->currentMarkData));
-
pfree(so);
scan->opaque = NULL;

--- 410,415 ----
***************
*** 430,443 ****
if (BufferIsValid(so->hashso_mrkbuf))
_hash_dropbuf(rel, so->hashso_mrkbuf);
so->hashso_mrkbuf = InvalidBuffer;
! 	ItemPointerSetInvalid(&(scan->currentMarkData));

! /* bump pin count on currentItemData and copy to currentMarkData */
! if (ItemPointerIsValid(&(scan->currentItemData)))
{
IncrBufferRefCount(so->hashso_curbuf);
so->hashso_mrkbuf = so->hashso_curbuf;
! scan->currentMarkData = scan->currentItemData;
}

PG_RETURN_VOID();
--- 430,443 ----
if (BufferIsValid(so->hashso_mrkbuf))
_hash_dropbuf(rel, so->hashso_mrkbuf);
so->hashso_mrkbuf = InvalidBuffer;
! 	ItemPointerSetInvalid(&(so->hashso_mrkpos));

! /* bump pin count on current buffer and copy to marked buffer */
! if (ItemPointerIsValid(&(so->hashso_curpos)))
{
IncrBufferRefCount(so->hashso_curbuf);
so->hashso_mrkbuf = so->hashso_curbuf;
! so->hashso_mrkpos = so->hashso_curpos;
}

PG_RETURN_VOID();
***************
*** 457,470 ****
if (BufferIsValid(so->hashso_curbuf))
_hash_dropbuf(rel, so->hashso_curbuf);
so->hashso_curbuf = InvalidBuffer;
! ItemPointerSetInvalid(&(scan->currentItemData));

! /* bump pin count on currentMarkData and copy to currentItemData */
! if (ItemPointerIsValid(&(scan->currentMarkData)))
{
IncrBufferRefCount(so->hashso_mrkbuf);
so->hashso_curbuf = so->hashso_mrkbuf;
! scan->currentItemData = scan->currentMarkData;
}

PG_RETURN_VOID();
--- 457,470 ----
if (BufferIsValid(so->hashso_curbuf))
_hash_dropbuf(rel, so->hashso_curbuf);
so->hashso_curbuf = InvalidBuffer;
! 	ItemPointerSetInvalid(&(so->hashso_curpos));

! /* bump pin count on marked buffer and copy to current buffer */
! if (ItemPointerIsValid(&(so->hashso_mrkpos)))
{
IncrBufferRefCount(so->hashso_mrkbuf);
so->hashso_curbuf = so->hashso_mrkbuf;
! so->hashso_curpos = so->hashso_mrkpos;
}

PG_RETURN_VOID();
Index: src/backend/access/hash/hashsearch.c
===================================================================
RCS file: /home/hlinnaka/pgcvsrepository/pgsql/src/backend/access/hash/hashsearch.c,v
retrieving revision 1.45
diff -c -r1.45 hashsearch.c
*** src/backend/access/hash/hashsearch.c	14 Jul 2006 14:52:17 -0000	1.45
--- src/backend/access/hash/hashsearch.c	12 Sep 2006 15:44:45 -0000
***************
*** 21,27 ****
/*
*	_hash_next() -- Get the next item in a scan.
*
!  *		On entry, we have a valid currentItemData in the scan, and a
*		pin and read lock on the page that contains that item.
*		We find the next item in the scan, if any.
*		On success exit, we have the page containing the next item
--- 21,27 ----
/*
*	_hash_next() -- Get the next item in a scan.
*
!  *		On entry, we have a valid hashso_curpos in the scan, and a
*		pin and read lock on the page that contains that item.
*		We find the next item in the scan, if any.
*		On success exit, we have the page containing the next item
***************
*** 49,55 ****
return false;

/* if we're here, _hash_step found a valid tuple */
! 	current = &(scan->currentItemData);
offnum = ItemPointerGetOffsetNumber(current);
_hash_checkpage(rel, buf, LH_BUCKET_PAGE | LH_OVERFLOW_PAGE);
page = BufferGetPage(buf);
--- 49,55 ----
return false;

/* if we're here, _hash_step found a valid tuple */
! current = &(so->hashso_curpos);
offnum = ItemPointerGetOffsetNumber(current);
_hash_checkpage(rel, buf, LH_BUCKET_PAGE | LH_OVERFLOW_PAGE);
page = BufferGetPage(buf);
***************
*** 129,135 ****

pgstat_count_index_scan(&scan->xs_pgstat_info);

! current = &(scan->currentItemData);
ItemPointerSetInvalid(current);

/*
--- 129,135 ----

pgstat_count_index_scan(&scan->xs_pgstat_info);

! current = &(so->hashso_curpos);
ItemPointerSetInvalid(current);

/*
***************
*** 224,230 ****
*	_hash_step() -- step to the next valid item in a scan in the bucket.
*
*		If no valid record exists in the requested direction, return
!  *		false.	Else, return true and set the CurrentItemData for the
*		scan to the right thing.
*
*		'bufP' points to the current buffer, which is pinned and read-locked.
--- 224,230 ----
*	_hash_step() -- step to the next valid item in a scan in the bucket.
*
*		If no valid record exists in the requested direction, return
!  *		false.	Else, return true and set the hashso_curpos for the
*		scan to the right thing.
*
*		'bufP' points to the current buffer, which is pinned and read-locked.
***************
*** 245,251 ****
BlockNumber blkno;
IndexTuple	itup;

! current = &(scan->currentItemData);

buf = *bufP;
_hash_checkpage(rel, buf, LH_BUCKET_PAGE | LH_OVERFLOW_PAGE);
--- 245,251 ----
BlockNumber blkno;
IndexTuple	itup;

! current = &(so->hashso_curpos);

buf = *bufP;
_hash_checkpage(rel, buf, LH_BUCKET_PAGE | LH_OVERFLOW_PAGE);
Index: src/backend/access/index/genam.c
===================================================================
RCS file: /home/hlinnaka/pgcvsrepository/pgsql/src/backend/access/index/genam.c,v
retrieving revision 1.58
diff -c -r1.58 genam.c
*** src/backend/access/index/genam.c	31 Jul 2006 20:08:59 -0000	1.58
--- src/backend/access/index/genam.c	12 Sep 2006 15:45:54 -0000
***************
*** 92,100 ****

scan->opaque = NULL;

- 	ItemPointerSetInvalid(&scan->currentItemData);
- 	ItemPointerSetInvalid(&scan->currentMarkData);
- 
ItemPointerSetInvalid(&scan->xs_ctup.t_self);
scan->xs_ctup.t_data = NULL;
scan->xs_cbuf = InvalidBuffer;
--- 92,97 ----
Index: src/include/access/gist_private.h
===================================================================
RCS file: /home/hlinnaka/pgcvsrepository/pgsql/src/include/access/gist_private.h,v
retrieving revision 1.23
diff -c -r1.23 gist_private.h
*** src/include/access/gist_private.h	7 Aug 2006 16:57:57 -0000	1.23
--- src/include/access/gist_private.h	12 Sep 2006 15:36:30 -0000
***************
*** 72,78 ****
--- 72,80 ----
GISTSTATE  *giststate;
MemoryContext tempCxt;
Buffer		curbuf;
+ 	ItemPointerData curpos;
Buffer		markbuf;
+ 	ItemPointerData markpos;
} GISTScanOpaqueData;

typedef GISTScanOpaqueData *GISTScanOpaque;
Index: src/include/access/hash.h
===================================================================
RCS file: /home/hlinnaka/pgcvsrepository/pgsql/src/include/access/hash.h,v
retrieving revision 1.73
diff -c -r1.73 hash.h
*** src/include/access/hash.h	13 Jul 2006 16:49:19 -0000	1.73
--- src/include/access/hash.h	12 Sep 2006 15:39:28 -0000
***************
*** 97,102 ****
--- 97,106 ----
*/
Buffer		hashso_curbuf;
Buffer		hashso_mrkbuf;
+ 
+ 	/* Current and marked position of the scan */
+ 	ItemPointerData hashso_curpos;
+ 	ItemPointerData hashso_mrkpos;
} HashScanOpaqueData;

typedef HashScanOpaqueData *HashScanOpaque;
Index: src/include/access/nbtree.h
===================================================================
RCS file: /home/hlinnaka/pgcvsrepository/pgsql/src/include/access/nbtree.h,v
retrieving revision 1.104
diff -c -r1.104 nbtree.h
*** src/include/access/nbtree.h	24 Aug 2006 01:18:34 -0000	1.104
--- src/include/access/nbtree.h	12 Sep 2006 15:55:17 -0000
***************
*** 383,391 ****
* items were killed, we re-lock the page to mark them killed, then unlock.
* Finally we drop the pin and step to the next page in the appropriate
* direction.
-  *
-  * NOTE: in this implementation, btree does not use or set the
-  * currentItemData and currentMarkData fields of IndexScanDesc at all.
*/

typedef struct BTScanPosItem	/* what we remember about each match */
--- 383,388 ----
Index: src/include/access/relscan.h
===================================================================
RCS file: /home/hlinnaka/pgcvsrepository/pgsql/src/include/access/relscan.h,v
retrieving revision 1.49
diff -c -r1.49 relscan.h
*** src/include/access/relscan.h	31 Jul 2006 20:09:05 -0000	1.49
--- src/include/access/relscan.h	12 Sep 2006 15:52:50 -0000
***************
*** 69,77 ****

/* index access method's private state */
void *opaque; /* access-method-specific info */
- /* these fields are used by some but not all AMs: */
- ItemPointerData currentItemData; /* current index pointer */
- ItemPointerData currentMarkData; /* marked position, if any */

/*
* xs_ctup/xs_cbuf are valid after a successful index_getnext. After
--- 69,74 ----

---------------------------(end of broadcast)---------------------------
TIP 1: if posting/reading through Usenet, please send an appropriate
subscribe-nomail command to majordomo@postgresql.org so that your
message can get through to the mailing list cleanly

--
Bruce Momjian bruce@momjian.us
EnterpriseDB http://www.enterprisedb.com

+ If your life is a hard drive, Christ can be your backup. +