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d93d3c843a
that it depends on
114 lines
3.0 KiB
C
114 lines
3.0 KiB
C
/*-------------------------------------------------------------------------
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*
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* htup.h--
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* POSTGRES heap tuple definitions.
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*
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*
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* Copyright (c) 1994, Regents of the University of California
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*
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* $Id: htup.h,v 1.3 1996/11/04 07:18:11 scrappy Exp $
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*
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*-------------------------------------------------------------------------
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*/
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#ifndef HTUP_H
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#define HTUP_H
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#include <utils/nabstime.h>
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#include <storage/itemptr.h>
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#define MinHeapTupleBitmapSize 32 /* 8 * 4 */
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/* check these, they are likely to be more severely limited by t_hoff */
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#define MaxHeapAttributeNumber 1600 /* 8 * 200 */
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/*
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* to avoid wasting space, the attributes should be layed out in such a
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* way to reduce structure padding.
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*/
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typedef struct HeapTupleData {
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unsigned int t_len; /* length of entire tuple */
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ItemPointerData t_ctid; /* current TID of this tuple */
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ItemPointerData t_chain; /* replaced tuple TID */
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Oid t_oid; /* OID of this tuple -- 4 bytes */
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CommandId t_cmin; /* insert CID stamp -- 2 bytes each */
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CommandId t_cmax; /* delete CommandId stamp */
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TransactionId t_xmin; /* insert XID stamp -- 4 bytes each */
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TransactionId t_xmax; /* delete XID stamp */
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AbsoluteTime t_tmin; /* time stamps -- 4 bytes each */
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AbsoluteTime t_tmax;
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int16 t_natts; /* number of attributes */
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char t_vtype; /* not used - padding */
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char t_infomask; /* whether tuple as null or variable
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* length attributes
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*/
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uint8 t_hoff; /* sizeof tuple header */
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bits8 t_bits[MinHeapTupleBitmapSize / 8];
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/* bit map of domains */
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/* MORE DATA FOLLOWS AT END OF STRUCT */
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} HeapTupleData;
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typedef HeapTupleData *HeapTuple;
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#define SelfItemPointerAttributeNumber (-1)
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#define ObjectIdAttributeNumber (-2)
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#define MinTransactionIdAttributeNumber (-3)
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#define MinCommandIdAttributeNumber (-4)
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#define MaxTransactionIdAttributeNumber (-5)
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#define MaxCommandIdAttributeNumber (-6)
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#define ChainItemPointerAttributeNumber (-7)
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#define AnchorItemPointerAttributeNumber (-8)
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#define MinAbsoluteTimeAttributeNumber (-9)
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#define MaxAbsoluteTimeAttributeNumber (-10)
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#define VersionTypeAttributeNumber (-11)
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#define FirstLowInvalidHeapAttributeNumber (-12)
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/* ----------------
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* support macros
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* ----------------
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*/
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#define GETSTRUCT(TUP) (((char *)(TUP)) + ((HeapTuple)(TUP))->t_hoff)
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/*
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* BITMAPLEN(NATTS) -
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* Computes minimum size of bitmap given number of domains.
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*/
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#define BITMAPLEN(NATTS) \
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((((((int)(NATTS) - 1) >> 3) + 4 - (MinHeapTupleBitmapSize >> 3)) \
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& ~03) + (MinHeapTupleBitmapSize >> 3))
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/*
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* HeapTupleIsValid
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* True iff the heap tuple is valid.
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*/
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#define HeapTupleIsValid(tuple) PointerIsValid(tuple)
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/*
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* information stored in t_infomask:
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*/
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#define HEAP_HASNULL 0x01 /* has null attribute(s) */
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#define HEAP_HASVARLENA 0x02 /* has variable length attribute(s) */
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#define HeapTupleNoNulls(tuple) \
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(!(((HeapTuple) (tuple))->t_infomask & HEAP_HASNULL))
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#define HeapTupleAllFixed(tuple) \
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(!(((HeapTuple) (tuple))->t_infomask & HEAP_HASVARLENA))
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#endif /* HTUP_H */
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