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/*
* (C) 2006-2007 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "buffer.h"
struct buffer *buffer_create(size_t max_size)
{
struct buffer *b;
b = malloc(sizeof(struct buffer));
if (b == NULL)
return NULL;
memset(b, 0, sizeof(struct buffer));
b->max_size = max_size;
INIT_LIST_HEAD(&b->head);
return b;
}
void buffer_destroy(struct buffer *b)
{
struct list_head *i, *tmp;
struct buffer_node *node;
/* XXX: set cur_size and num_elems */
list_for_each_safe(i, tmp, &b->head) {
node = (struct buffer_node *) i;
list_del(i);
free(node);
}
free(b);
}
static struct buffer_node *buffer_node_create(const void *data, size_t size)
{
struct buffer_node *n;
n = malloc(sizeof(struct buffer_node) + size);
if (n == NULL)
return NULL;
INIT_LIST_HEAD(&n->head);
n->size = size;
memcpy(n->data, data, size);
return n;
}
int buffer_add(struct buffer *b, const void *data, size_t size)
{
int ret = 0;
struct buffer_node *n;
/* does it fit this buffer? */
if (size > b->max_size) {
errno = ENOSPC;
ret = -1;
goto err;
}
retry:
/* buffer is full: kill the oldest entry */
if (b->cur_size + size > b->max_size) {
n = (struct buffer_node *) b->head.prev;
list_del(b->head.prev);
b->cur_size -= n->size;
free(n);
goto retry;
}
n = buffer_node_create(data, size);
if (n == NULL) {
ret = -1;
goto err;
}
list_add(&n->head, &b->head);
b->cur_size += size;
b->num_elems++;
err:
return ret;
}
void buffer_del(struct buffer *b, void *data)
{
struct buffer_node *n = container_of(data, struct buffer_node, data);
list_del(&n->head);
b->cur_size -= n->size;
b->num_elems--;
free(n);
}
void buffer_iterate(struct buffer *b,
void *data,
int (*iterate)(void *data1, void *data2))
{
struct list_head *i, *tmp;
struct buffer_node *n;
list_for_each_safe(i, tmp, &b->head) {
n = (struct buffer_node *) i;
if (iterate(n->data, data))
break;
}
}
unsigned int buffer_len(struct buffer *b)
{
return b->num_elems;
}
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