[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@via.ecp.fr>  */ 
! #define IFREESPC(p)        (PageGetFreeSpace(p) - sizeof(HeapTupleData) - sizeof(struct varlena) - sizeof(int32))
#defineIMAXBLK            8092 #define IMINBLK            512 
 
--- 72,81 ----  *        For subsequent notes, [PA] is Pascal Andr,Ai(B <andre@via.ecp.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
currentoffset (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;