neatvnc/inc/bitmap.h

85 lines
2.1 KiB
C

/*
* Copyright (c) 2019 Andri Yngvason
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
* REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
* INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
* LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
* OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
* PERFORMANCE OF THIS SOFTWARE.
*/
#pragma once
#include <stdint.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdbool.h>
#define UDIV_UP(a, b) (((a) + (b) - 1) / (b))
struct bitmap {
size_t n_elem;
uint64_t data[0];
};
static inline struct bitmap *bitmap_alloc(size_t bitlen)
{
size_t n_elem = UDIV_UP(bitlen, 64);
struct bitmap *self = calloc(1, sizeof(*self) + n_elem * sizeof(*self->data));
if (!self)
return NULL;
self->n_elem = n_elem;
return self;
}
static inline void bitmap_clear_all(struct bitmap *self)
{
for (size_t i = 0; i < self->n_elem; ++i)
self->data[i] = 0;
}
static inline int bitmap_is_empty(const struct bitmap *self)
{
for (size_t i = 0; i < self->n_elem; ++i)
if (self->data[i])
return 0;
return 1;
}
static inline int bitmap_is_set(const struct bitmap *self, int index)
{
return !!(self->data[index / 64] & (1ULL << (index % 64)));
}
static inline void bitmap_clear(struct bitmap* self, int index)
{
self->data[index / 64] &= ~(1ULL << (index % 64));
}
static inline void bitmap_set_cond(struct bitmap* self, int index, bool cond)
{
self->data[index / 64] |= ((uint64_t)cond) << (index % 64);
}
static inline void bitmap_set(struct bitmap* self, int index)
{
bitmap_set_cond(self, index, true);
}
static inline int bitmap_runlength(const struct bitmap *self, int start)
{
int r = 0;
while (bitmap_is_set(self, start + r)) ++r;
return r;
}