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/*-------------------------------------------------------------------------
*
* itemptr.c
* POSTGRES disk item pointer code.
*
* Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/storage/page/itemptr.c,v 1.19 2006/10/04 00:29:58 momjian Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "storage/itemptr.h"
/*
* ItemPointerEquals
* Returns true if both item pointers point to the same item,
* otherwise returns false.
*
* Note:
* Asserts that the disk item pointers are both valid!
*/
bool
ItemPointerEquals(ItemPointer pointer1, ItemPointer pointer2)
{
if (ItemPointerGetBlockNumber(pointer1) ==
ItemPointerGetBlockNumber(pointer2) &&
ItemPointerGetOffsetNumber(pointer1) ==
ItemPointerGetOffsetNumber(pointer2))
return true;
else
return false;
}
/*
* ItemPointerCompare
* Generic btree-style comparison for item pointers.
*/
int32
ItemPointerCompare(ItemPointer arg1, ItemPointer arg2)
{
/*
* Don't use ItemPointerGetBlockNumber or ItemPointerGetOffsetNumber here,
* because they assert ip_posid != 0 which might not be true for a
* user-supplied TID.
*/
BlockNumber b1 = BlockIdGetBlockNumber(&(arg1->ip_blkid));
BlockNumber b2 = BlockIdGetBlockNumber(&(arg2->ip_blkid));
if (b1 < b2)
return -1;
else if (b1 > b2)
return 1;
else if (arg1->ip_posid < arg2->ip_posid)
return -1;
else if (arg1->ip_posid > arg2->ip_posid)
return 1;
else
return 0;
}
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