/*
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* Bitfield
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* Copyright (c) 2013, Jouni Malinen <j@w1.fi>
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*
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* This software may be distributed under the terms of the BSD license.
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* See README for more details.
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*/
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#include "includes.h"
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#include "common.h"
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#include "bitfield.h"
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struct bitfield {
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u8 *bits;
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size_t max_bits;
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};
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struct bitfield * bitfield_alloc(size_t max_bits)
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{
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struct bitfield *bf;
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bf = os_zalloc(sizeof(*bf) + (max_bits + 7) / 8);
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if (bf == NULL)
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return NULL;
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bf->bits = (u8 *) (bf + 1);
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bf->max_bits = max_bits;
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return bf;
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}
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void bitfield_free(struct bitfield *bf)
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{
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os_free(bf);
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}
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void bitfield_set(struct bitfield *bf, size_t bit)
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{
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if (bit >= bf->max_bits)
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return;
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bf->bits[bit / 8] |= BIT(bit % 8);
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}
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void bitfield_clear(struct bitfield *bf, size_t bit)
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{
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if (bit >= bf->max_bits)
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return;
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bf->bits[bit / 8] &= ~BIT(bit % 8);
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}
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int bitfield_is_set(struct bitfield *bf, size_t bit)
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{
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if (bit >= bf->max_bits)
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return 0;
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return !!(bf->bits[bit / 8] & BIT(bit % 8));
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}
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static int first_zero(u8 val)
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{
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int i;
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for (i = 0; i < 8; i++) {
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if (!(val & 0x01))
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return i;
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val >>= 1;
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}
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return -1;
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}
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int bitfield_get_first_zero(struct bitfield *bf)
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{
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size_t i;
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for (i = 0; i < (bf->max_bits + 7) / 8; i++) {
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if (bf->bits[i] != 0xff)
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break;
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}
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if (i == (bf->max_bits + 7) / 8)
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return -1;
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i = i * 8 + first_zero(bf->bits[i]);
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if (i >= bf->max_bits)
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return -1;
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return i;
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}
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