Files
sesimos/src/lib/list.c
2023-01-02 21:48:06 +01:00

103 lines
2.9 KiB
C

#include "list.h"
#include <malloc.h>
#include <memory.h>
#include <errno.h>
#define FACTOR 4
typedef struct {
int init_size, elem_size, max_size, size;
} list_meta_t;
static void *list_resize(list_meta_t *list, int new_size) {
if (new_size <= 0)
return NULL;
list_meta_t *new_ptr = realloc(list, sizeof(list_meta_t) + list->elem_size * new_size);
if (new_ptr == NULL)
return NULL;
new_ptr->max_size = new_size;
return new_ptr;
}
void *list_create(int elem_size, int init_elem_n) {
if (elem_size <= 0 || init_elem_n <= 0) {
errno = EINVAL;
return NULL;
}
void *list_ptr = malloc(sizeof(list_meta_t) + elem_size * init_elem_n);
list_meta_t *list = list_ptr;
list->init_size = init_elem_n;
list->elem_size = elem_size;
list->max_size = init_elem_n;
list->size = 0;
return (unsigned char *) list_ptr + sizeof(list_meta_t);
}
unsigned int list_size(void *list_ptr) {
list_meta_t *list = (void *) ((unsigned char *) list_ptr - sizeof(list_meta_t));
return list->size;
}
void *list_insert(void *list_ptr, void *elem, int n) {
list_meta_t *list = (void *) ((unsigned char *) list_ptr - sizeof(list_meta_t));
if (n < 0)
n = list->size + n + 1;
if (list->size >= list->max_size) {
if ((list = list_resize(list, list->max_size * FACTOR)) == NULL) {
return NULL;
}
}
unsigned char *array = list_ptr;
if (n < list->size)
memmove(array + (n + 1) * list->elem_size, array + n * list->elem_size, (list->size - n) * list->elem_size);
memcpy(array + n * list->elem_size, elem, list->elem_size);
list->size++;
return (unsigned char *) list + sizeof(list_meta_t);
}
void *list_append(void *list_ptr, void *elem) {
return list_insert(list_ptr, elem, -1);
}
void *list_remove(void *list_ptr, int n) {
list_meta_t *list = (void *) ((unsigned char *) list_ptr - sizeof(list_meta_t));
if (n < 0)
n = list->size + n;
unsigned char *array = list_ptr;
if (list->size > 1 && n < list->size)
memmove(array + n * list->elem_size, array + (n + 1) * list->elem_size, (list->size - n - 1) * list->elem_size);
list->size--;
if (list->size < list->max_size / FACTOR && list->max_size / FACTOR >= list->init_size) {
if ((list = list_resize(list, list->max_size / FACTOR)) == NULL) {
return NULL;
}
}
return (unsigned char *) list + sizeof(list_meta_t);
}
void *list_clear(void *list_ptr) {
list_meta_t *list = (void *) ((unsigned char *) list_ptr - sizeof(list_meta_t));
list->size = 0;
memset(list_ptr, 0, list->max_size * list->elem_size);
list->max_size = list->init_size;
return (unsigned char *) list_resize(list, list->max_size * list->elem_size) + sizeof(list_meta_t);
}
void list_free(void *list_ptr) {
list_meta_t *list = (void *) ((unsigned char *) list_ptr - sizeof(list_meta_t));
free(list);
}