4 * This file is part of FFmpeg.
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 #include "libavutil/mem.h"
24 #include "libavutil/avassert.h"
26 typedef struct QueueEntry QueueEntry;
40 static inline QueueEntry *create_entry(void *val)
42 QueueEntry *entry = av_malloc(sizeof(*entry));
48 Queue* ff_queue_create(void)
50 Queue *q = av_malloc(sizeof(*q));
54 q->head = create_entry(q);
55 q->tail = create_entry(q);
57 if (!q->head || !q->tail) {
64 q->head->next = q->tail;
65 q->tail->prev = q->head;
73 void ff_queue_destroy(Queue *q)
80 while (entry != NULL) {
81 QueueEntry *temp = entry;
89 size_t ff_queue_size(Queue *q)
91 return q ? q->length : 0;
94 void *ff_queue_peek_front(Queue *q)
96 if (!q || q->length == 0)
99 return q->head->next->value;
102 void *ff_queue_peek_back(Queue *q)
104 if (!q || q->length == 0)
107 return q->tail->prev->value;
110 int ff_queue_push_front(Queue *q, void *v)
112 QueueEntry *new_entry;
113 QueueEntry *original_next;
117 new_entry = create_entry(v);
120 original_next = q->head->next;
122 q->head->next = new_entry;
123 original_next->prev = new_entry;
124 new_entry->prev = q->head;
125 new_entry->next = original_next;
131 int ff_queue_push_back(Queue *q, void *v)
133 QueueEntry *new_entry;
134 QueueEntry *original_prev;
138 new_entry = create_entry(v);
141 original_prev = q->tail->prev;
143 q->tail->prev = new_entry;
144 original_prev->next = new_entry;
145 new_entry->next = q->tail;
146 new_entry->prev = original_prev;
152 void *ff_queue_pop_front(Queue *q)
155 QueueEntry *new_head_next;
158 if (!q || q->length == 0)
161 front = q->head->next;
162 new_head_next = front->next;
165 q->head->next = new_head_next;
166 new_head_next->prev = q->head;
173 void *ff_queue_pop_back(Queue *q)
176 QueueEntry *new_tail_prev;
179 if (!q || q->length == 0)
182 back = q->tail->prev;
183 new_tail_prev = back->prev;
186 q->tail->prev = new_tail_prev;
187 new_tail_prev->next = q->tail;