postgresql/src/backend/lib/bit.c

48 lines
1.1 KiB
C

/*-------------------------------------------------------------------------
*
* bit.c
* Standard bit array code.
*
* Portions Copyright (c) 1996-2000, PostgreSQL, Inc
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/lib/Attic/bit.c,v 1.9 2000/01/26 05:56:26 momjian Exp $
*
*-------------------------------------------------------------------------
*/
/*
* utils/memutils.h contains declarations of the functions in this file
*/
#include "postgres.h"
#include "utils/bit.h"
void
BitArraySetBit(BitArray bitArray, BitIndex bitIndex)
{
bitArray[bitIndex / BitsPerByte]
|= (1 << (BitsPerByte - (bitIndex % BitsPerByte) - 1));
return;
}
void
BitArrayClearBit(BitArray bitArray, BitIndex bitIndex)
{
bitArray[bitIndex / BitsPerByte]
&= ~(1 << (BitsPerByte - (bitIndex % BitsPerByte) - 1));
return;
}
bool
BitArrayBitIsSet(BitArray bitArray, BitIndex bitIndex)
{
return ((bool) (((bitArray[bitIndex / BitsPerByte] &
(1 << (BitsPerByte - (bitIndex % BitsPerByte)
- 1)
)
) != 0) ? 1 : 0));
}