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New HeapTuple structure/interface.

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This commit is contained in:
Vadim B. Mikheev
1998-11-27 19:33:35 +00:00
parent 4d7188039a
commit 2435c7d501
8 changed files with 119 additions and 106 deletions
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41
src/include/access/htup.h
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@@ -6,7 +6,7 @@
*
* Copyright (c) 1994, Regents of the University of California
*
* $Id: htup.h,v 1.10 1998/09/01 04:34:14 momjian Exp $
* $Id: htup.h,v 1.11 1998/11/27 19:33:31 vadim Exp $
*
*-------------------------------------------------------------------------
*/
@@ -26,10 +26,8 @@
* to avoid wasting space, the attributes should be layed out in such a
* way to reduce structure padding.
*/
typedef struct HeapTupleData
typedef struct HeapTupleHeaderData
{
unsigned int t_len; /* length of entire tuple */
Oid t_oid; /* OID of this tuple -- 4 bytes */
CommandId t_cmin; /* insert CID stamp -- 4 bytes each */
@@ -38,7 +36,7 @@ typedef struct HeapTupleData
TransactionId t_xmin; /* insert XID stamp -- 4 bytes each */
TransactionId t_xmax; /* delete XID stamp */
ItemPointerData t_ctid; /* current TID of this tuple */
ItemPointerData t_ctid; /* current TID of this or newer tuple */
int16 t_natts; /* number of attributes */
@@ -50,10 +48,9 @@ typedef struct HeapTupleData
/* bit map of domains */
/* MORE DATA FOLLOWS AT END OF STRUCT */
} HeapTupleData;
typedef HeapTupleData *HeapTuple;
} HeapTupleHeaderData;
typedef HeapTupleHeaderData *HeapTupleHeader;
#define SelfItemPointerAttributeNumber (-1)
#define ObjectIdAttributeNumber (-2)
@@ -66,11 +63,33 @@ typedef HeapTupleData *HeapTuple;
/* If you make any changes above, the order off offsets in this must change */
extern long heap_sysoffset[];
/*
* This new HeapTuple for version >= 6.5 and this is why it was changed:
*
* 1. t_len moved off on-disk tuple data - ItemIdData is used to get len;
* 2. t_ctid above is not self tuple TID now - it may point to
* updated version of tuple (required by MVCC);
* 3. someday someone let tuple to cross block boundaries -
* he have to add something below...
*/
typedef struct HeapTupleData
{
uint32 t_len; /* length of *t_data */
ItemPointerData t_self; /* SelfItemPointer */
HeapTupleHeader t_data; /* */
} HeapTupleData;
typedef HeapTupleData *HeapTuple;
#define HEAPTUPLESIZE DOUBLEALIGN(sizeof(HeapTupleData))
/* ----------------
* support macros
* ----------------
*/
#define GETSTRUCT(TUP) (((char *)(TUP)) + ((HeapTuple)(TUP))->t_hoff)
#define GETSTRUCT(TUP) (((char *)((HeapTuple)(TUP))->t_data) + \
((HeapTuple)(TUP))->t_data->t_hoff)
/*
@@ -101,9 +120,9 @@ extern long heap_sysoffset[];
#define HEAP_XACT_MASK 0x0F00 /* */
#define HeapTupleNoNulls(tuple) \
(!(((HeapTuple) (tuple))->t_infomask & HEAP_HASNULL))
(!(((HeapTuple) (tuple))->t_data->t_infomask & HEAP_HASNULL))
#define HeapTupleAllFixed(tuple) \
(!(((HeapTuple) (tuple))->t_infomask & HEAP_HASVARLENA))
(!(((HeapTuple) (tuple))->t_data->t_infomask & HEAP_HASVARLENA))
#endif /* HTUP_H */