PipeWire 0.3.38
ringbuffer.h
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1/* Simple Plugin API
2 *
3 * Copyright © 2018 Wim Taymans
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining a
6 * copy of this software and associated documentation files (the "Software"),
7 * to deal in the Software without restriction, including without limitation
8 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9 * and/or sell copies of the Software, and to permit persons to whom the
10 * Software is furnished to do so, subject to the following conditions:
11 *
12 * The above copyright notice and this permission notice (including the next
13 * paragraph) shall be included in all copies or substantial portions of the
14 * Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
21 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
22 * DEALINGS IN THE SOFTWARE.
23 */
24
25#ifndef SPA_RINGBUFFER_H
26#define SPA_RINGBUFFER_H
27
28#ifdef __cplusplus
29extern "C" {
30#endif
31
37struct spa_ringbuffer;
38
39#include <string.h>
40
41#include <spa/utils/defs.h>
42
47 uint32_t readindex; /*< the current read index */
48 uint32_t writeindex; /*< the current write index */
49};
50
51#define SPA_RINGBUFFER_INIT() (struct spa_ringbuffer) { 0, 0 }
52
58/* static */ inline void spa_ringbuffer_init(struct spa_ringbuffer *rbuf)
59{
60 *rbuf = SPA_RINGBUFFER_INIT();
61}
62
69/* static */ inline void spa_ringbuffer_set_avail(struct spa_ringbuffer *rbuf, uint32_t size)
70{
71 rbuf->readindex = 0;
72 rbuf->writeindex = size;
73}
74
85/* static */ inline int32_t spa_ringbuffer_get_read_index(struct spa_ringbuffer *rbuf, uint32_t *index)
86{
87 *index = __atomic_load_n(&rbuf->readindex, __ATOMIC_RELAXED);
88 return (int32_t) (__atomic_load_n(&rbuf->writeindex, __ATOMIC_ACQUIRE) - *index);
89}
90
102/* static */ inline void
104 const void *buffer, uint32_t size,
105 uint32_t offset, void *data, uint32_t len)
106{
107 uint32_t l0 = SPA_MIN(len, size - offset), l1 = len - l0;
108 spa_memcpy(data, SPA_PTROFF(buffer, offset, void), l0);
109 if (SPA_UNLIKELY(l1 > 0))
110 spa_memcpy(SPA_PTROFF(data, l0, void), buffer, l1);
111}
112
119/* static */ inline void spa_ringbuffer_read_update(struct spa_ringbuffer *rbuf, int32_t index)
120{
121 __atomic_store_n(&rbuf->readindex, index, __ATOMIC_RELEASE);
122}
123
135/* static */ inline int32_t spa_ringbuffer_get_write_index(struct spa_ringbuffer *rbuf, uint32_t *index)
136{
137 *index = __atomic_load_n(&rbuf->writeindex, __ATOMIC_RELAXED);
138 return (int32_t) (*index - __atomic_load_n(&rbuf->readindex, __ATOMIC_ACQUIRE));
139}
140
152/* static */ inline void
154 void *buffer, uint32_t size,
155 uint32_t offset, const void *data, uint32_t len)
156{
157 uint32_t l0 = SPA_MIN(len, size - offset), l1 = len - l0;
158 spa_memcpy(SPA_PTROFF(buffer, offset, void), data, l0);
159 if (SPA_UNLIKELY(l1 > 0))
160 spa_memcpy(buffer, SPA_PTROFF(data, l0, void), l1);
161}
162
169/* static */ inline void spa_ringbuffer_write_update(struct spa_ringbuffer *rbuf, int32_t index)
170{
171 __atomic_store_n(&rbuf->writeindex, index, __ATOMIC_RELEASE);
172}
173
179#ifdef __cplusplus
180} /* extern "C" */
181#endif
182
183#endif /* SPA_RINGBUFFER_H */
#define SPA_MIN(a, b)
Definition: defs.h:128
void spa_ringbuffer_write_data(struct spa_ringbuffer *rbuf, void *buffer, uint32_t size, uint32_t offset, const void *data, uint32_t len)
Write len bytes to buffer starting offset.
Definition: ringbuffer.h:153
void spa_ringbuffer_read_update(struct spa_ringbuffer *rbuf, int32_t index)
Update the read pointer to index.
Definition: ringbuffer.h:119
#define SPA_RINGBUFFER_INIT()
Definition: ringbuffer.h:51
void spa_ringbuffer_read_data(struct spa_ringbuffer *rbuf, const void *buffer, uint32_t size, uint32_t offset, void *data, uint32_t len)
Read len bytes from rbuf starting offset.
Definition: ringbuffer.h:103
int32_t spa_ringbuffer_get_read_index(struct spa_ringbuffer *rbuf, uint32_t *index)
Get the read index and available bytes for reading.
Definition: ringbuffer.h:85
#define SPA_UNLIKELY(x)
Definition: defs.h:242
void spa_ringbuffer_init(struct spa_ringbuffer *rbuf)
Initialize a spa_ringbuffer with size.
Definition: ringbuffer.h:58
void spa_ringbuffer_set_avail(struct spa_ringbuffer *rbuf, uint32_t size)
Sets the pointers so that the ringbuffer contains size bytes.
Definition: ringbuffer.h:69
int32_t spa_ringbuffer_get_write_index(struct spa_ringbuffer *rbuf, uint32_t *index)
Get the write index and the number of bytes inside the ringbuffer.
Definition: ringbuffer.h:135
#define spa_memcpy(d, s, n)
Definition: defs.h:326
void spa_ringbuffer_write_update(struct spa_ringbuffer *rbuf, int32_t index)
Update the write pointer to index.
Definition: ringbuffer.h:169
#define SPA_PTROFF(ptr_, offset_, type_)
Return the address (buffer + offset) as pointer of type.
Definition: defs.h:164
Definition: filter.c:59
user data to add to an object
Definition: media-session.c:113
A ringbuffer type.
Definition: ringbuffer.h:46
uint32_t readindex
Definition: ringbuffer.h:47
uint32_t writeindex
Definition: ringbuffer.h:48