/* | |
* Copyright (c) 2020 | |
* | |
* This file is part of FFmpeg. | |
* | |
* FFmpeg is free software; you can redistribute it and/or | |
* modify it under the terms of the GNU Lesser General Public | |
* License as published by the Free Software Foundation; either | |
* version 2.1 of the License, or (at your option) any later version. | |
* | |
* FFmpeg 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 | |
* Lesser General Public License for more details. | |
* | |
* You should have received a copy of the GNU Lesser General Public | |
* License along with FFmpeg; if not, write to the Free Software | |
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
*/ | |
/** | |
* Linear double-ended data structure | |
*/ | |
typedef struct Queue Queue; | |
/** | |
* @brief Create a Queue instance. | |
* It initializes the length of the Queue as 0. | |
* | |
* @return Pointer to the Queue | |
* @retval NULL if allocation fails | |
*/ | |
Queue *ff_queue_create(void); | |
/** | |
* @brief Destroy the Queue instance. | |
* It also frees all elements of the Queue. | |
*/ | |
void ff_queue_destroy(Queue *q); | |
/** | |
* @brief Return the length of the Queue | |
*/ | |
size_t ff_queue_size(Queue *q); | |
/** | |
* @brief Return a pointer to the data | |
* at the head of the queue. | |
* | |
* @retval NULL if null pointer was passed | |
* or queue is empty | |
*/ | |
void *ff_queue_peek_front(Queue *q); | |
/** | |
* @brief Return a pointer to the data at | |
* the tail of the queue. | |
* | |
* @retval NULL if null pointer was passed | |
* or queue is empty | |
*/ | |
void *ff_queue_peek_back(Queue *q); | |
/** | |
* @brief Add data to the head of the queue. | |
* It increases the length of Queue by one. | |
* | |
* @param q pointer to the Queue. | |
* @param v data to be added | |
* @return The length of the Queue | |
* @retval 0 if the pointer to queue is NULL | |
* @retval -1 if new entry cannot be created | |
*/ | |
int ff_queue_push_front(Queue *q, void *v); | |
/** | |
* @brief Add data to the tail of the queue. | |
* It increases the length of Queue by one. | |
* | |
* @param q pointer to the Queue | |
* @param v data to be added | |
* @return The length of the Queue | |
* @retval 0 if the pointer to queue is NULL | |
* @retval -1 if new entry cannot be created | |
*/ | |
int ff_queue_push_back(Queue *q, void *v); | |
/** | |
* @brief Remove and free first element from | |
* the Queue. It shrinks the length of Queue | |
* by one. | |
* | |
* @param q pointer to the Queue. | |
* @return The value of first element as void. | |
* If a null pointer or empty queue is passed, | |
* it returns NULL | |
*/ | |
void *ff_queue_pop_front(Queue *q); | |
/** | |
* @brief Remove and free last element from | |
* the Queue. It shrinks the length of Queue | |
* by one. | |
* | |
* @param q pointer to the Queue. | |
* @return The value of last element as void. | |
* If a null pointer or empty queue is passed, | |
* it returns NULL | |
*/ | |
void *ff_queue_pop_back(Queue *q); | |