| /* |
| * (C) 2005-2011 by Pablo Neira Ayuso <pablo@netfilter.org> |
| * |
| * This program is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| */ |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <errno.h> |
| |
| #include "internal/stack.h" |
| |
| struct stack { |
| int num_elems; |
| int max_elems; |
| size_t elem_size; |
| char *data; |
| }; |
| |
| struct stack *stack_create(size_t elem_size, int max_elems) |
| { |
| struct stack *s; |
| |
| s = calloc(sizeof(struct stack), 1); |
| if (s == NULL) |
| return NULL; |
| |
| s->data = calloc(elem_size * max_elems, 1); |
| if (s->data == NULL) { |
| free(s); |
| return NULL; |
| } |
| s->elem_size = elem_size; |
| s->max_elems = max_elems; |
| |
| return s; |
| } |
| |
| void stack_destroy(struct stack *s) |
| { |
| free(s->data); |
| free(s); |
| } |
| |
| int stack_push(struct stack *s, void *data) |
| { |
| if (s->num_elems >= s->max_elems) { |
| errno = ENOSPC; |
| return -1; |
| } |
| memcpy(s->data + (s->elem_size * s->num_elems), data, s->elem_size); |
| s->num_elems++; |
| return 0; |
| } |
| |
| int stack_pop(struct stack *s, void *data) |
| { |
| if (s->num_elems <= 0) { |
| errno = EINVAL; |
| return -1; |
| } |
| s->num_elems--; |
| memcpy(data, s->data + (s->elem_size * s->num_elems), s->elem_size); |
| return 0; |
| } |