105 lines
2.6 KiB
C
105 lines
2.6 KiB
C
/*
|
|
* Copyright 2008 Arsen Chaloyan
|
|
*
|
|
* Licensed under the Apache License, Version 2.0 (the "License");
|
|
* you may not use this file except in compliance with the License.
|
|
* You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS,
|
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
* See the License for the specific language governing permissions and
|
|
* limitations under the License.
|
|
*/
|
|
|
|
#include <stdlib.h>
|
|
#include "apt_cyclic_queue.h"
|
|
|
|
struct apt_cyclic_queue_t {
|
|
void **data;
|
|
apr_size_t max_size;
|
|
apr_size_t actual_size;
|
|
apr_size_t head;
|
|
apr_size_t tail;
|
|
};
|
|
|
|
static apt_bool_t apt_cyclic_queue_resize(apt_cyclic_queue_t *queue);
|
|
|
|
|
|
APT_DECLARE(apt_cyclic_queue_t*) apt_cyclic_queue_create(apr_size_t size)
|
|
{
|
|
apt_cyclic_queue_t *queue = malloc(sizeof(apt_cyclic_queue_t));
|
|
queue->max_size = size;
|
|
queue->actual_size = 0;
|
|
queue->data = malloc(sizeof(void*) * queue->max_size);
|
|
queue->head = queue->tail = 0;
|
|
return queue;
|
|
}
|
|
|
|
APT_DECLARE(void) apt_cyclic_queue_destroy(apt_cyclic_queue_t *queue)
|
|
{
|
|
if(queue->data) {
|
|
free(queue->data);
|
|
queue->data = NULL;
|
|
}
|
|
free(queue);
|
|
}
|
|
|
|
APT_DECLARE(apt_bool_t) apt_cyclic_queue_push(apt_cyclic_queue_t *queue, void *obj)
|
|
{
|
|
if(queue->actual_size >= queue->max_size) {
|
|
if(apt_cyclic_queue_resize(queue) != TRUE) {
|
|
return FALSE;
|
|
}
|
|
}
|
|
|
|
queue->data[queue->head] = obj;
|
|
queue->head = (queue->head + 1) % queue->max_size;
|
|
queue->actual_size++;
|
|
return TRUE;
|
|
}
|
|
|
|
APT_DECLARE(void*) apt_cyclic_queue_pop(apt_cyclic_queue_t *queue)
|
|
{
|
|
void *obj = NULL;
|
|
if(queue->actual_size) {
|
|
obj = queue->data[queue->tail];
|
|
queue->tail = (queue->tail + 1) % queue->max_size;
|
|
queue->actual_size--;
|
|
}
|
|
return obj;
|
|
}
|
|
|
|
APT_DECLARE(void) apt_cyclic_queue_clear(apt_cyclic_queue_t *queue)
|
|
{
|
|
queue->actual_size = 0;
|
|
queue->head = queue->tail = 0;
|
|
}
|
|
|
|
APT_DECLARE(apt_bool_t) apt_cyclic_queue_is_empty(apt_cyclic_queue_t *queue)
|
|
{
|
|
return queue->actual_size ? TRUE : FALSE;
|
|
}
|
|
|
|
static apt_bool_t apt_cyclic_queue_resize(apt_cyclic_queue_t *queue)
|
|
{
|
|
apr_size_t new_size = queue->max_size + queue->max_size/2;
|
|
void **new_data = malloc(sizeof(void*) * new_size);
|
|
apr_size_t offset;
|
|
|
|
offset = queue->max_size - queue->head;
|
|
memcpy(new_data, queue->data + queue->head, sizeof(void*) * offset);
|
|
if(queue->head) {
|
|
memcpy(new_data + offset, queue->data, sizeof(void*) * queue->head);
|
|
}
|
|
|
|
queue->tail = 0;
|
|
queue->head = queue->max_size;
|
|
queue->max_size = new_size;
|
|
free(queue->data);
|
|
queue->data = new_data;
|
|
return TRUE;
|
|
}
|