src/main/common/bitarray.h

   1 /*
   2  * This file is part of Cleanflight.
   3  *
   4  * Cleanflight is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 3 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * Cleanflight is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with Cleanflight.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #pragma once
  19
  20 #include <stdbool.h>
  21 #include <stddef.h>
  22
  23 /*
  24  * These functions expect array to be 4-byte aligned since they alias array
  25  * to an uint32_t pointer in order to work fast. Use the BITARRAY_DECLARE()
  26  * macro to declare a bit array that can be safely used by them.
  27  */
  28
  29 typedef uint32_t bitarrayElement_t;
  30
  31 #define BITARRAY_DECLARE(name, bits) bitarrayElement_t name[(bits + 31) / 32]
  32
  33 bool bitArrayGet(const bitarrayElement_t *array, unsigned bit);
  34 void bitArraySet(bitarrayElement_t *array, unsigned bit);
  35 void bitArrayClr(bitarrayElement_t *array, unsigned bit);
  36
  37 void bitArraySetAll(bitarrayElement_t *array, size_t size);
  38 void bitArrayClrAll(bitarrayElement_t *array, size_t size);
  39
  40 #define BITARRAY_SET_ALL(array) bitArraySetAll(array, sizeof(array))
  41 #define BITARRAY_CLR_ALL(array) bitArrayClrAll(array, sizeof(array))
  42
  43 // Returns the first set bit with pos >= start_bit, or -1 if all bits
  44 // are zero. Note that size must indicate the size of array in bytes.
  45 // In most cases, you should use the BITARRAY_FIND_FIRST_SET() macro
  46 // to call this function.
  47 int bitArrayFindFirstSet(const bitarrayElement_t *array, unsigned start_bit, size_t size);
  48
  49 #define BITARRAY_FIND_FIRST_SET(array, start_bit) bitArrayFindFirstSet(array, start_bit, sizeof(array))