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/* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult AB
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
This library 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with this library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
MA 02111-1307, USA */
/*
Handling of uchar arrays as large bitmaps.
*/
#include "mysys_priv.h"
#include <my_bitmap.h>
pthread_mutex_t LOCK_bitmap;
void bitmap_set_bit(uchar *bitmap, uint bitmap_size, uint bitmap_bit) {
if((bitmap_bit != MY_BIT_NONE) && (bitmap_bit < bitmap_size*8)) {
pthread_mutex_lock(&LOCK_bitmap);
bitmap[bitmap_bit / 8] |= (1 << bitmap_bit % 8);
pthread_mutex_unlock(&LOCK_bitmap);
};
};
uint bitmap_set_next(uchar *bitmap, uint bitmap_size) {
uint bit_found = MY_BIT_NONE;
int i, b;
pthread_mutex_lock(&LOCK_bitmap);
for(i=0; (i<bitmap_size) && (bit_found==MY_BIT_NONE); i++) {
if(bitmap[i] == 0xff) continue;
for(b=0; (b<8) && (bit_found==MY_BIT_NONE); b++)
if((bitmap[i] & 1<<b) == 0) {
bit_found = (i*8)+b;
bitmap[i] |= 1<<b;
};
};
pthread_mutex_unlock(&LOCK_bitmap);
return bit_found;
};
void bitmap_clear_bit(uchar *bitmap, uint bitmap_size, uint bitmap_bit) {
if((bitmap_bit != MY_BIT_NONE) && (bitmap_bit < bitmap_size*8)) {
pthread_mutex_lock(&LOCK_bitmap);
bitmap[bitmap_bit / 8] &= ~(1 << bitmap_bit % 8);
pthread_mutex_unlock(&LOCK_bitmap);
};
};
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