[CURRENT] large object fix

>>To Bruce:
>>Thanks for taking care of my previous patches for current. If
>>included patch is ok, I will make one for current.
>
>Now I'm working on lobj in current tree(Currently lobj in 6.5 seems
>broken).

Done.

o overwriting an existing lobj now works
o 8KB garbage block always inserted problem is fixed

--
Tatsuo Ishii
--------------------------- cut here ---------------------------------
*** pgsql/src/backend/storage/large_object/inv_api.c.orig Wed Feb 24 12:45:24 1999
--- pgsql/src/backend/storage/large_object/inv_api.c Thu Feb 25 15:58:10 1999
***************
*** 72,78 ****
* For subsequent notes, [PA] is Pascal Andr,Ai(B <andre(at)via(dot)ecp(dot)fr>
*/

! #define IFREESPC(p) (PageGetFreeSpace(p) - sizeof(HeapTupleData) - sizeof(struct varlena) - sizeof(int32))
#define IMAXBLK 8092
#define IMINBLK 512

--- 72,81 ----
* For subsequent notes, [PA] is Pascal Andr,Ai(B <andre(at)via(dot)ecp(dot)fr>
*/

! #define IFREESPC(p) (PageGetFreeSpace(p) - \
! DOUBLEALIGN(offsetof(HeapTupleHeaderData,t_bits)) - \
! DOUBLEALIGN(sizeof(struct varlena) + sizeof(int32)) - \
! sizeof(double))
#define IMAXBLK 8092
#define IMINBLK 512

***************
*** 623,646 ****
|| obj_desc->offset < obj_desc->lowbyte
|| !ItemPointerIsValid(&(obj_desc->htid)))
{

/* initialize scan key if not done */
if (obj_desc->iscan == (IndexScanDesc) NULL)
{
- ScanKeyData skey;
-
/*
* As scan index may be prematurely closed (on commit), we
* must use object current offset (was 0) to reinitialize the
* entry [ PA ].
*/
- ScanKeyEntryInitialize(&skey, 0x0, 1, F_INT4GE,
- Int32GetDatum(obj_desc->offset));
obj_desc->iscan = index_beginscan(obj_desc->index_r,
(bool) 0, (uint16) 1,
&skey);
! }
!
do
{
res = index_getnext(obj_desc->iscan, ForwardScanDirection);
--- 626,650 ----
|| obj_desc->offset < obj_desc->lowbyte
|| !ItemPointerIsValid(&(obj_desc->htid)))
{
+ ScanKeyData skey;
+
+ ScanKeyEntryInitialize(&skey, 0x0, 1, F_INT4GE,
+ Int32GetDatum(obj_desc->offset));

/* initialize scan key if not done */
if (obj_desc->iscan == (IndexScanDesc) NULL)
{
/*
* As scan index may be prematurely closed (on commit), we
* must use object current offset (was 0) to reinitialize the
* entry [ PA ].
*/
obj_desc->iscan = index_beginscan(obj_desc->index_r,
(bool) 0, (uint16) 1,
&skey);
! } else {
! index_rescan(obj_desc->iscan, false, &skey);
! }
do
{
res = index_getnext(obj_desc->iscan, ForwardScanDirection);
***************
*** 673,678 ****
--- 677,685 ----
{
tuple->t_self = obj_desc->htid;
heap_fetch(obj_desc->heap_r, SnapshotNow, tuple, buffer);
+ if (tuple->t_data == NULL) {
+ elog(ERROR, "inv_fetchtup: heap_fetch failed");
+ }
}

/*
***************
*** 744,755 ****

nblocks = RelationGetNumberOfBlocks(hr);

! if (nblocks > 0)
buffer = ReadBuffer(hr, nblocks - 1);
! else
buffer = ReadBuffer(hr, P_NEW);
!
! page = BufferGetPage(buffer);

/*
* If the last page is too small to hold all the data, and it's too
--- 751,765 ----

nblocks = RelationGetNumberOfBlocks(hr);

! if (nblocks > 0) {
buffer = ReadBuffer(hr, nblocks - 1);
! page = BufferGetPage(buffer);
! }
! else {
buffer = ReadBuffer(hr, P_NEW);
! page = BufferGetPage(buffer);
! PageInit(page, BufferGetPageSize(buffer), 0);
! }

/*
* If the last page is too small to hold all the data, and it's too
***************
*** 864,875 ****

nblocks = RelationGetNumberOfBlocks(hr);

! if (nblocks > 0)
newbuf = ReadBuffer(hr, nblocks - 1);
! else
newbuf = ReadBuffer(hr, P_NEW);

- newpage = BufferGetPage(newbuf);
freespc = IFREESPC(newpage);

/*
--- 874,889 ----

nblocks = RelationGetNumberOfBlocks(hr);

! if (nblocks > 0) {
newbuf = ReadBuffer(hr, nblocks - 1);
! newpage = BufferGetPage(newbuf);
! }
! else {
newbuf = ReadBuffer(hr, P_NEW);
+ newpage = BufferGetPage(newbuf);
+ PageInit(newpage, BufferGetPageSize(newbuf), 0);
+ }

freespc = IFREESPC(newpage);

/*
***************
*** 973,978 ****
--- 987,995 ----
WriteBuffer(buffer);
if (newbuf != buffer)
WriteBuffer(newbuf);
+
+ /* Tuple id is no longer valid */
+ ItemPointerSetInvalid(&(obj_desc->htid));

/* done */
return nwritten;