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/*

 * Copyright (c) 2002-2005 The TenDRA Project <http://www.tendra.org/>.

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions are met:

 *

 * 1. Redistributions of source code must retain the above copyright notice,

 *    this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright notice,

 *    this list of conditions and the following disclaimer in the documentation

 *    and/or other materials provided with the distribution.

 * 3. Neither the name of The TenDRA Project nor the names of its contributors

 *    may be used to endorse or promote products derived from this software

 *    without specific, prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS

 * IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,

 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR

 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

 * EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;

 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,

 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR

 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF

 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 *

 * $Id$

 */

/*

    		 Crown Copyright (c) 1997

    This TenDRA(r) Computer Program is subject to Copyright

    owned by the United Kingdom Secretary of State for Defence

    acting through the Defence Evaluation and Research Agency

    (DERA).  It is made available to Recipients with a

    royalty-free licence for its use, reproduction, transfer

    to other parties and amendment for any purpose not excluding

    product development provided that any such use et cetera

    shall be deemed to be acceptance of the following conditions:-

        (1) Its Recipients shall ensure that this Notice is

        reproduced upon any copies or amended versions of it;

        (2) Any amended version of it shall be clearly marked to

        show both the nature of and the organisation responsible

        for the relevant amendment or amendments;

        (3) Its onward transfer from a recipient to another

        party shall be deemed to be that party's acceptance of

        these conditions;

        (4) DERA gives no warranty or assurance as to its

        quality or suitability for any purpose and DERA accepts

        no liability whatsoever in relation to any use to which

        it may be put.

*/

/**** bitvec.c --- Bit vector manipulation.

 *

 ** Author: Steve Folkes <smf@hermes.mod.uk>

 *

 **** Commentary:

 *

 * This file implements the bit vector manipulation routines specified in

 * "bitvec.h".  See that file for more details.

 *

 **** Change Log:

 * $Log: bitvec.c,v $

 * Revision 1.1.1.1  1998/01/17  15:57:43  release

 * First version to be checked into rolling release.

 *

 * Revision 1.2  1994/12/15  09:56:59  smf

 * Brought into line with OSSG C Coding Standards Document, as per

 * "CR94_178.sid+tld-update".

 *

 * Revision 1.1.1.1  1994/07/25  16:05:47  smf

 * Initial import of library shared files.

 *

**/

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

#include "bitvec.h"

/*--------------------------------------------------------------------------*/

static unsigned		bitvec_size;

static unsigned		bitvec_valid_bits;

static ByteT		bitvec_mask;

#define NUM_BITS	((unsigned)(CHAR_BIT))

/*--------------------------------------------------------------------------*/

void

bitvec_set_size(unsigned size)

{

    bitvec_valid_bits = size;

    bitvec_size       = ((size + NUM_BITS - (unsigned)1) / NUM_BITS);

    bitvec_mask       = (ByteT)0;

    if (size % NUM_BITS) {

	unsigned i;

	unsigned mask =0;

	for (i = (NUM_BITS - (size % NUM_BITS)); i; i--) {

	    mask >>= 1;

	    mask  |= ((unsigned)1 << (NUM_BITS - (unsigned)1));

	}

	bitvec_mask = (ByteT)mask;

    }

    bitvec_mask = (~bitvec_mask);

}

void

bitvec_init(BitVecP bitvec)

{

    bitvec->bits = ALLOCATE_VECTOR(ByteT, bitvec_size);

}

void

bitvec_copy(BitVecP to, BitVecP from)

{

    to->bits = ALLOCATE_VECTOR(ByteT, bitvec_size);

   (void)memcpy((GenericP)(to->bits), (GenericP)(from->bits),

		(SizeT)bitvec_size);

}

void

bitvec_replace(BitVecP to, BitVecP from)

{

   (void)memcpy((GenericP)(to->bits), (GenericP)(from->bits),

		(SizeT)bitvec_size);

}

void

bitvec_empty(BitVecP bitvec)

{

   (void)memset((GenericP)(bitvec->bits), 0, (SizeT)bitvec_size);

}

BoolT

bitvec_is_empty(BitVecP bitvec)

{

    ByteP    bitvec_bits = (bitvec->bits);

    unsigned bytes       = bitvec_size;

    while (bytes--) {

	if (*bitvec_bits++) {

	    return(FALSE);

	}

    }

    return(TRUE);

}

BoolT

bitvec_is_full(BitVecP bitvec)

{

    ByteP    bitvec_bits = (bitvec->bits);

    unsigned bytes       = bitvec_size;

    while (bytes--) {

	ByteT byte = (*bitvec_bits++);

	if (bytes == 0) {

	    byte |= (ByteT)~bitvec_mask;

	}

	byte = ~byte;

	if (byte) {

	    return(FALSE);

	}

    }

    return(TRUE);

}

void

bitvec_set(BitVecP bitvec, unsigned bit)

{

    ASSERT(bit < bitvec_valid_bits);

   (bitvec->bits)[bit / NUM_BITS] |= (ByteT)(1 << (bit % NUM_BITS));

}

BoolT

bitvec_is_set(BitVecP bitvec, unsigned bit)

{

    ASSERT(bit < bitvec_valid_bits);

    return((bitvec->bits)[bit / NUM_BITS] & ((ByteT)1 << (bit % NUM_BITS)));

}

void

bitvec_or(BitVecP to, BitVecP from)

{

    ByteP    to_bits   = (to->bits);

    ByteP    from_bits = (from->bits);

    unsigned bytes     = bitvec_size;

    while (bytes--) {

	(*to_bits++) |= (*from_bits++);

    }

}

void

bitvec_and(BitVecP to, BitVecP from)

{

    ByteP    to_bits   = (to->bits);

    ByteP    from_bits = (from->bits);

    unsigned bytes     = bitvec_size;

    while (bytes--) {

	(*to_bits++) &= (*from_bits++);

    }

}

void

bitvec_not(BitVecP to)

{

    ByteP    to_bits = (to->bits);

    unsigned bytes   = bitvec_size;

    while (bytes--) {

	(*to_bits) = (~(*to_bits));

	to_bits++;

    }

   (to->bits)[bitvec_size - 1] &= bitvec_mask;

}

BoolT

bitvec_equal(BitVecP bitvec1, BitVecP bitvec2)

{

    ByteP    bitvec1_bits = (bitvec1->bits);

    ByteP    bitvec2_bits = (bitvec2->bits);

    unsigned bytes        = bitvec_size;

    while (bytes--) {

	if ((*bitvec1_bits++) != (*bitvec2_bits++)) {

	    return(FALSE);

	}

    }

    return(TRUE);

}

BoolT

bitvec_intersects(BitVecP bitvec1, BitVecP bitvec2)

{

    ByteP    bitvec1_bits = (bitvec1->bits);

    ByteP    bitvec2_bits = (bitvec2->bits);

    unsigned bytes        = bitvec_size;

    while (bytes--) {

	if ((*bitvec1_bits++) & (*bitvec2_bits++)) {

	    return(TRUE);

	}

    }

    return(FALSE);

}

unsigned

bitvec_num_bits(BitVecP bitvec)

{

    unsigned i;

    unsigned num_bits = 0;

    for (i = 0; i < bitvec_valid_bits; i++) {

	if (bitvec_is_set(bitvec, i)) {

	    num_bits++;

	}

    }

    return(num_bits);

}

unsigned

bitvec_first_bit(BitVecP bitvec)

{

    unsigned i;

    for (i = 0; i < bitvec_valid_bits; i++) {

	if (bitvec_is_set(bitvec, i)) {

	    return(i);

	}

    }

    return(bitvec_valid_bits);

}

BoolT

bitvec_next_bit(BitVecP bitvec, unsigned *next_ref)

{

    unsigned i;

    for (i = ((*next_ref) + 1); i < bitvec_valid_bits; i++) {

	if (bitvec_is_set(bitvec, i)) {

	    *next_ref = i;

	    return(TRUE);

	}

    }

    return(FALSE);

}

void

bitvec_destroy(BitVecP bitvec)

{

    DEALLOCATE(bitvec->bits);

}

void

write_bitvec_indices(OStreamP ostream, BitVecP bitvec)

{

    unsigned num_bits_set = 0;

    unsigned i;

    for (i = 0; i < bitvec_valid_bits; i++) {

	if (bitvec_is_set(bitvec, i)) {

	    num_bits_set++;

	}

    }

    for (i = 0; i < bitvec_valid_bits; i++) {

	if (bitvec_is_set(bitvec, i)) {

	    write_unsigned(ostream, i);

	    num_bits_set--;

	    if (num_bits_set == 1) {

		write_cstring(ostream, " & ");

	    } else if (num_bits_set != 0) {

		write_cstring(ostream, ", ");

	    }

	}

    }

}

/*

 * Local variables(smf):

 * eval: (include::add-path-entry "../os-interface" "../generated")

 * end:

**/