memarray.h

/*
 * SPDX-FileCopyrightText: 2018 Tobias Heider <heidert@nm.ifi.lmu.de>
 * SPDX-FileCopyrightText: 2020 Koen Zandberg <koen@bergzand.net>
 * SPDX-License-Identifier: LGPL-2.1-only
 */
 
#pragma once

 
#include <assert.h>
#include <stdint.h>
#include <stddef.h>
#include <string.h>
 
#ifdef __cplusplus
extern "C" {
#endif

typedef struct {
    void *free_data;    
    size_t size;        
} memarray_t;

typedef struct memarray_element {
    struct memarray_element *next;  
} memarray_element_t;

void memarray_init(memarray_t *mem, void *data, size_t size, size_t num);

static inline void *memarray_alloc(memarray_t *mem)
{
    assert(mem != NULL);
 
    void *free = mem->free_data;
    if (free) {
        mem->free_data = *((void **)mem->free_data);
    }
    return free;
}

static inline void *memarray_calloc(memarray_t *mem)
{
    void *new = memarray_alloc(mem);
    if (new) {
        memset(new, 0, mem->size);
    }
    return new;
}

static inline void memarray_free(memarray_t *mem, void *ptr)
{
    assert((mem != NULL) && (ptr != NULL));
 
    memcpy(ptr, &mem->free_data, sizeof(void *));
    mem->free_data = ptr;
}

void memarray_extend(memarray_t *mem, void *data, size_t num);

int memarray_reduce(memarray_t *mem, void *data, size_t num);

size_t memarray_available(memarray_t *mem);
 
#ifdef __cplusplus
}
#endif