~drizzle-trunk/drizzle/development

/*****************************************************************************

Copyright (c) 1994, 2009, Innobase Oy. All Rights Reserved.

This program is free software; you can redistribute it and/or modify it under

the terms of the GNU General Public License as published by the Free Software

Foundation; version 2 of the License.

This program is distributed in the hope that it will be useful, but WITHOUT

ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS

FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with

this program; if not, write to the Free Software Foundation, Inc., 59 Temple

Place, Suite 330, Boston, MA 02111-1307 USA

*****************************************************************************/

/**************************************************************//**

@file include/ut0byte.ic

Utilities for byte operations

Created 5/30/1994 Heikki Tuuri

*******************************************************************/

/*******************************************************//**

Creates a 64-bit dulint out of two ulints.

@return	created dulint */

UNIV_INLINE

dulint

ut_dulint_create(

/*=============*/

	ulint	high,	/*!< in: high-order 32 bits */

	ulint	low)	/*!< in: low-order 32 bits */

{

	dulint	res;

	ut_ad(high <= 0xFFFFFFFF);

	ut_ad(low <= 0xFFFFFFFF);

	res.high = high;

	res.low	 = low;

	return(res);

}

/*******************************************************//**

Gets the high-order 32 bits of a dulint.

@return	32 bits in ulint */

UNIV_INLINE

ulint

ut_dulint_get_high(

/*===============*/

	dulint	d)	/*!< in: dulint */

{

	return(d.high);

}

/*******************************************************//**

Gets the low-order 32 bits of a dulint.

@return	32 bits in ulint */

UNIV_INLINE

ulint

ut_dulint_get_low(

/*==============*/

	dulint	d)	/*!< in: dulint */

{

	return(d.low);

}

/*******************************************************//**

Converts a dulint (a struct of 2 ulints) to ib_int64_t, which is a 64-bit

integer type.

@return	value in ib_int64_t type */

UNIV_INLINE

ib_int64_t

ut_conv_dulint_to_longlong(

/*=======================*/

	dulint	d)	/*!< in: dulint */

{

	return((ib_int64_t)d.low

	       + (((ib_int64_t)d.high) << 32));

}

/*******************************************************//**

Tests if a dulint is zero.

@return	TRUE if zero */

UNIV_INLINE

ibool

ut_dulint_is_zero(

/*==============*/

	dulint	a)	/*!< in: dulint */

{

	if ((a.low == 0) && (a.high == 0)) {

		return(TRUE);

	}

	return(FALSE);

}

/*******************************************************//**

Compares two dulints.

@return	-1 if a < b, 0 if a == b, 1 if a > b */

UNIV_INLINE

int

ut_dulint_cmp(

/*==========*/

	dulint	a,	/*!< in: dulint */

	dulint	b)	/*!< in: dulint */

{

	if (a.high > b.high) {

		return(1);

	} else if (a.high < b.high) {

		return(-1);

	} else if (a.low > b.low) {

		return(1);

	} else if (a.low < b.low) {

		return(-1);

	} else {

		return(0);

	}

}

/*******************************************************//**

Calculates the max of two dulints.

@return	max(a, b) */

UNIV_INLINE

dulint

ut_dulint_get_max(

/*==============*/

	dulint	a,	/*!< in: dulint */

	dulint	b)	/*!< in: dulint */

{

	if (ut_dulint_cmp(a, b) > 0) {

		return(a);

	}

	return(b);

}

/*******************************************************//**

Calculates the min of two dulints.

@return	min(a, b) */

UNIV_INLINE

dulint

ut_dulint_get_min(

/*==============*/

	dulint	a,	/*!< in: dulint */

	dulint	b)	/*!< in: dulint */

{

	if (ut_dulint_cmp(a, b) > 0) {

		return(b);

	}

	return(a);

}

/*******************************************************//**

Adds a ulint to a dulint.

@return	sum a + b */

UNIV_INLINE

dulint

ut_dulint_add(

/*==========*/

	dulint	a,	/*!< in: dulint */

	ulint	b)	/*!< in: ulint */

{

	if (0xFFFFFFFFUL - b >= a.low) {

		a.low += b;

		return(a);

	}

	a.low = a.low - (0xFFFFFFFFUL - b) - 1;

	a.high++;

	return(a);

}

/*******************************************************//**

Subtracts a ulint from a dulint.

@return	a - b */

UNIV_INLINE

dulint

ut_dulint_subtract(

/*===============*/

	dulint	a,	/*!< in: dulint */

	ulint	b)	/*!< in: ulint, b <= a */

{

	if (a.low >= b) {

		a.low -= b;

		return(a);

	}

	b -= a.low + 1;

	a.low = 0xFFFFFFFFUL - b;

	ut_ad(a.high > 0);

	a.high--;

	return(a);

}

/*******************************************************//**

Subtracts a dulint from another. NOTE that the difference must be positive

and smaller that 4G.

@return	a - b */

UNIV_INLINE

ulint

ut_dulint_minus(

/*============*/

	dulint	a,	/*!< in: dulint; NOTE a must be >= b and at most

			2 to power 32 - 1 greater */

	dulint	b)	/*!< in: dulint */

{

	ulint	diff;

	if (a.high == b.high) {

		ut_ad(a.low >= b.low);

		return(a.low - b.low);

	}

	ut_ad(a.high == b.high + 1);

	diff = (ulint)(0xFFFFFFFFUL - b.low);

	diff += 1 + a.low;

	ut_ad(diff > a.low);

	return(diff);

}

/********************************************************//**

Rounds a dulint downward to a multiple of a power of 2.

@return	rounded value */

UNIV_INLINE

dulint

ut_dulint_align_down(

/*=================*/

	dulint	 n,		/*!< in: number to be rounded */

	ulint	 align_no)	/*!< in: align by this number which must be a

				power of 2 */

{

	ulint	low, high;

	ut_ad(align_no > 0);

	ut_ad(((align_no - 1) & align_no) == 0);

	low = ut_dulint_get_low(n);

	high = ut_dulint_get_high(n);

	low = low & ~(align_no - 1);

	return(ut_dulint_create(high, low));

}

/********************************************************//**

Rounds a dulint upward to a multiple of a power of 2.

@return	rounded value */

UNIV_INLINE

dulint

ut_dulint_align_up(

/*===============*/

	dulint	 n,		/*!< in: number to be rounded */

	ulint	 align_no)	/*!< in: align by this number which must be a

				power of 2 */

{

	return(ut_dulint_align_down(ut_dulint_add(n, align_no - 1), align_no));

}

/********************************************************//**

Rounds ib_uint64_t downward to a multiple of a power of 2.

@return	rounded value */

UNIV_INLINE

ib_uint64_t

ut_uint64_align_down(

/*=================*/

	ib_uint64_t	 n,		/*!< in: number to be rounded */

	ulint		 align_no)	/*!< in: align by this number

					which must be a power of 2 */

{

	ut_ad(align_no > 0);

	ut_ad(ut_is_2pow(align_no));

	return(n & ~((ib_uint64_t) align_no - 1));

}

/********************************************************//**

Rounds ib_uint64_t upward to a multiple of a power of 2.

@return	rounded value */

UNIV_INLINE

ib_uint64_t

ut_uint64_align_up(

/*===============*/

	ib_uint64_t	 n,		/*!< in: number to be rounded */

	ulint		 align_no)	/*!< in: align by this number

					which must be a power of 2 */

{

	ib_uint64_t	align_1 = (ib_uint64_t) align_no - 1;

	ut_ad(align_no > 0);

	ut_ad(ut_is_2pow(align_no));

	return((n + align_1) & ~align_1);

}

/*********************************************************//**

The following function rounds up a pointer to the nearest aligned address.

@return	aligned pointer */

UNIV_INLINE

void*

ut_align(

/*=====*/

	void*	ptr,		/*!< in: pointer */

	ulint	align_no)	/*!< in: align by this number */

{

	ut_ad(align_no > 0);

	ut_ad(((align_no - 1) & align_no) == 0);

	ut_ad(ptr);

	ut_ad(sizeof(void*) == sizeof(ulint));

	return((void*)((((ulint)ptr) + align_no - 1) & ~(align_no - 1)));

}

/*********************************************************//**

The following function rounds down a pointer to the nearest

aligned address.

@return	aligned pointer */

UNIV_INLINE

void*

ut_align_down(

/*==========*/

	const void*	ptr,		/*!< in: pointer */

	ulint		align_no)	/*!< in: align by this number */

{

	ut_ad(align_no > 0);

	ut_ad(((align_no - 1) & align_no) == 0);

	ut_ad(ptr);

	ut_ad(sizeof(void*) == sizeof(ulint));

	return((void*)((((ulint)ptr)) & ~(align_no - 1)));

}

/*********************************************************//**

The following function computes the offset of a pointer from the nearest

aligned address.

@return	distance from aligned pointer */

UNIV_INLINE

ulint

ut_align_offset(

/*============*/

	const void*	ptr,		/*!< in: pointer */

	ulint		align_no)	/*!< in: align by this number */

{

	ut_ad(align_no > 0);

	ut_ad(((align_no - 1) & align_no) == 0);

	ut_ad(ptr);

	ut_ad(sizeof(void*) == sizeof(ulint));

	return(((ulint)ptr) & (align_no - 1));

}

/*****************************************************************//**

Gets the nth bit of a ulint.

@return	TRUE if nth bit is 1; 0th bit is defined to be the least significant */

UNIV_INLINE

ibool

ut_bit_get_nth(

/*===========*/

	ulint	a,	/*!< in: ulint */

	ulint	n)	/*!< in: nth bit requested */

{

	ut_ad(n < 8 * sizeof(ulint));

#if TRUE != 1

# error "TRUE != 1"

#endif

	return(1 & (a >> n));

}

/*****************************************************************//**

Sets the nth bit of a ulint.

@return	the ulint with the bit set as requested */

UNIV_INLINE

ulint

ut_bit_set_nth(

/*===========*/

	ulint	a,	/*!< in: ulint */

	ulint	n,	/*!< in: nth bit requested */

	ibool	val)	/*!< in: value for the bit to set */

{

	ut_ad(n < 8 * sizeof(ulint));

#if TRUE != 1

# error "TRUE != 1"

#endif

	if (val) {

		return(((ulint) 1 << n) | a);

	} else {

		return(~((ulint) 1 << n) & a);

	}

}