bitfield.h

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/*
 * Copyright (c) 2024 ykat UG (haftungsbeschraenkt) - All Rights Reserved
 *
 * Permission for non-commercial use is hereby granted,
 * free of charge, without warranty of any kind.
 */
#ifndef ZRTOS_BITFIELD_H
#define ZRTOS_BITFIELD_H
#ifdef __cplusplus
extern "C" {
#endif


#include <zrtos/types.h>
#include <zrtos/mem.h>


typedef uint8_t zrtos_bitfield_mask_t;

#pragma pack(push,1)
typedef struct{
    uint8_t val;
}zrtos_bitfield_t;
#pragma pack(pop)

#define ZRTOS_BITFIELD__NFDBITS (8 * sizeof(zrtos_bitfield_mask_t))
#define ZRTOS_BITFIELD__ELT(d)  (((size_t)d) / ZRTOS_BITFIELD__NFDBITS)
#define ZRTOS_BITFIELD__MASK(d) ((zrtos_bitfield_mask_t) (1 << (((size_t)d) % ZRTOS_BITFIELD__NFDBITS)))
#define ZRTOS_BITFIELD__MASK_MSB(d) ((zrtos_bitfield_mask_t) (1 << (7-(((size_t)d) % ZRTOS_BITFIELD__NFDBITS))))

void zrtos_bitfield__set(zrtos_bitfield_t *thiz,size_t pos,bool val){
    zrtos_bitfield_mask_t *tmp = &(&thiz->val)[ZRTOS_BITFIELD__ELT(pos)];
    if(val){
        *tmp |= ZRTOS_BITFIELD__MASK(pos);
    }else{
        *tmp &= ~ZRTOS_BITFIELD__MASK(pos);
    }
}

void zrtos_bitfield__set_msb(zrtos_bitfield_t *thiz,size_t pos,bool val){
    zrtos_bitfield_mask_t *tmp = &(&thiz->val)[ZRTOS_BITFIELD__ELT(pos)];
    if(val){
        *tmp |= ZRTOS_BITFIELD__MASK_MSB(pos);
    }else{
        *tmp &= ~ZRTOS_BITFIELD__MASK_MSB(pos);
    }
}

bool zrtos_bitfield__get(zrtos_bitfield_t *thiz,size_t pos){
    return 0 != (
        (&thiz->val)[ZRTOS_BITFIELD__ELT(pos)] & ZRTOS_BITFIELD__MASK(pos)
    );
}

uint8_t zrtos_bitfield__get_uint8(zrtos_bitfield_t *thiz,size_t pos){
    return (&thiz->val)[pos];
}

void zrtos_bitfield__zero(zrtos_bitfield_t *thiz,size_t len){
    zrtos_mem__zero(thiz,len);
}

void zrtos_bitfield__copy(zrtos_bitfield_t *thiz,zrtos_bitfield_t *src,size_t len){
    zrtos_mem__cpy(thiz,src,len);
}

size_t zrtos_bitfield__find_first(
     zrtos_bitfield_t *thiz
    ,size_t len
    ,size_t start
    ,bool zero
){
    len *= ZRTOS_BITFIELD__NFDBITS;
    for(size_t i=start;i<len;i++){
        bool val = zrtos_bitfield__get(thiz,i);

        if(zero){
            val = !val;
        }

        if(val){
            return i;
        }
    }
    return ZRTOS_TYPES__SIZE_MAX;
}

size_t zrtos_bitfield__find_first_zero(
     zrtos_bitfield_t *thiz
    ,size_t len
    ,size_t start
){
    return zrtos_bitfield__find_first(
         thiz
        ,len
        ,start
        ,true
    );
}

size_t zrtos_bitfield__find_first_set(
     zrtos_bitfield_t *thiz
    ,size_t len
    ,size_t start
){
    return zrtos_bitfield__find_first(
         thiz
        ,len
        ,start
        ,false
    );
}

#define ZRTOS_BITFIELD__EACH(thiz,len,pos)                                     \
    for(size_t pos = 0                                                         \
       ; ZRTOS_TYPES__SIZE_MAX                                                 \
       != (pos = zrtos_bitfield__find_first_set(thiz,len,pos))                 \
       ;pos++                                                                  \
    )


#ifdef __cplusplus
}
#endif
#endif