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/*-------------------------------------------------------------------------
*
* itup.h
* POSTGRES index tuple definitions.
*
*
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $Id: itup.h,v 1.30 2001/02/22 21:48:49 momjian Exp $
*
*-------------------------------------------------------------------------
*/
#ifndef ITUP_H
#define ITUP_H
#include "access/ibit.h"
#include "access/tupdesc.h"
#include "access/tupmacs.h"
#include "storage/itemptr.h"
typedef struct IndexTupleData
{
ItemPointerData t_tid; /* reference TID to heap tuple */
/* ---------------
* t_info is layed out in the following fashion:
*
* 15th (high) bit: has nulls
* 14th bit: has varlenas
* 13th bit: unused
* 12-0 bit: size of tuple
* ---------------
*/
unsigned short t_info; /* various info about tuple */
/*
* please make sure sizeof(IndexTupleData) is MAXALIGN'ed. See
* IndexInfoFindDataOffset() for the reason.
*/
} IndexTupleData; /* MORE DATA FOLLOWS AT END OF STRUCT */
typedef IndexTupleData *IndexTuple;
typedef struct InsertIndexResultData
{
ItemPointerData pointerData;
} InsertIndexResultData;
typedef InsertIndexResultData *InsertIndexResult;
typedef struct RetrieveIndexResultData
{
ItemPointerData index_iptr;
ItemPointerData heap_iptr;
} RetrieveIndexResultData;
typedef RetrieveIndexResultData *RetrieveIndexResult;
/* ----------------
* externs
* ----------------
*/
#define INDEX_SIZE_MASK 0x1FFF
#define INDEX_NULL_MASK 0x8000
#define INDEX_VAR_MASK 0x4000
/* bit 0x2000 is not used */
#define IndexTupleSize(itup) ((Size) (((IndexTuple) (itup))->t_info & INDEX_SIZE_MASK))
#define IndexTupleDSize(itup) ((Size) ((itup).t_info & INDEX_SIZE_MASK))
#define IndexTupleHasNulls(itup) ((((IndexTuple) (itup))->t_info & INDEX_NULL_MASK))
#define IndexTupleHasVarlenas(itup) ((((IndexTuple) (itup))->t_info & INDEX_VAR_MASK))
#define IndexTupleHasMinHeader(itup) (!IndexTupleHasNulls(itup))
/*
* Takes an infomask as argument (primarily because this needs to be usable
* at index_formtuple time so enough space is allocated).
*
* Change me if adding an attribute to IndexTuples!!!!!!!!!!!
*/
#define IndexInfoFindDataOffset(t_info) \
( \
(!((unsigned short)(t_info) & INDEX_NULL_MASK)) ? \
( \
(Size)sizeof(IndexTupleData) \
) \
: \
( \
(Size)MAXALIGN(sizeof(IndexTupleData) + sizeof(IndexAttributeBitMapData)) \
) \
)
/* ----------------
* index_getattr
*
* This gets called many times, so we macro the cacheable and NULL
* lookups, and call noncachegetattr() for the rest.
*
* ----------------
*/
#define index_getattr(tup, attnum, tupleDesc, isnull) \
( \
AssertMacro(PointerIsValid(isnull) && (attnum) > 0), \
*(isnull) = false, \
!IndexTupleHasNulls(tup) ? \
( \
(tupleDesc)->attrs[(attnum)-1]->attcacheoff >= 0 ? \
( \
fetchatt((tupleDesc)->attrs[(attnum)-1], \
(char *) (tup) + \
( \
IndexTupleHasMinHeader(tup) ? \
sizeof (*(tup)) \
: \
IndexInfoFindDataOffset((tup)->t_info) \
) \
+ (tupleDesc)->attrs[(attnum)-1]->attcacheoff) \
) \
: \
nocache_index_getattr((tup), (attnum), (tupleDesc), (isnull)) \
) \
: \
( \
(att_isnull((attnum)-1, (char *)(tup) + sizeof(*(tup)))) ? \
( \
*(isnull) = true, \
(Datum)NULL \
) \
: \
( \
nocache_index_getattr((tup), (attnum), (tupleDesc), (isnull)) \
) \
) \
)
/* indextuple.h */
extern IndexTuple index_formtuple(TupleDesc tupleDescriptor,
Datum *value, char *null);
extern Datum nocache_index_getattr(IndexTuple tup, int attnum,
TupleDesc tupleDesc, bool *isnull);
extern RetrieveIndexResult FormRetrieveIndexResult(ItemPointer indexItemPointer,
ItemPointer heapItemPointer);
extern void CopyIndexTuple(IndexTuple source, IndexTuple *target);
#endif /* ITUP_H */
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