PipeWire  0.3.66
ringbuffer.h
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1 /* Simple Plugin API */
2 /* SPDX-FileCopyrightText: Copyright © 2018 Wim Taymans */
3 /* SPDX-License-Identifier: MIT */
4 
5 #ifndef SPA_RINGBUFFER_H
6 #define SPA_RINGBUFFER_H
7 
8 #ifdef __cplusplus
9 extern "C" {
10 #endif
11 
22 struct spa_ringbuffer;
23 
24 #include <string.h>
25 
26 #include <spa/utils/defs.h>
27 
31 struct spa_ringbuffer {
32  uint32_t readindex; /*< the current read index */
33  uint32_t writeindex; /*< the current write index */
34 };
35 
36 #define SPA_RINGBUFFER_INIT() ((struct spa_ringbuffer) { 0, 0 })
37 
43 static inline void spa_ringbuffer_init(struct spa_ringbuffer *rbuf)
44 {
45  *rbuf = SPA_RINGBUFFER_INIT();
46 }
47 
54 static inline void spa_ringbuffer_set_avail(struct spa_ringbuffer *rbuf, uint32_t size)
55 {
56  rbuf->readindex = 0;
57  rbuf->writeindex = size;
58 }
59 
70 static inline int32_t spa_ringbuffer_get_read_index(struct spa_ringbuffer *rbuf, uint32_t *index)
71 {
72  *index = __atomic_load_n(&rbuf->readindex, __ATOMIC_RELAXED);
73  return (int32_t) (__atomic_load_n(&rbuf->writeindex, __ATOMIC_ACQUIRE) - *index);
74 }
75 
87 static inline void
89  const void *buffer, uint32_t size,
90  uint32_t offset, void *data, uint32_t len)
91 {
92  uint32_t l0 = SPA_MIN(len, size - offset), l1 = len - l0;
93  spa_memcpy(data, SPA_PTROFF(buffer, offset, void), l0);
94  if (SPA_UNLIKELY(l1 > 0))
95  spa_memcpy(SPA_PTROFF(data, l0, void), buffer, l1);
96 }
97 
104 static inline void spa_ringbuffer_read_update(struct spa_ringbuffer *rbuf, int32_t index)
105 {
106  __atomic_store_n(&rbuf->readindex, index, __ATOMIC_RELEASE);
107 }
108 
120 static inline int32_t spa_ringbuffer_get_write_index(struct spa_ringbuffer *rbuf, uint32_t *index)
121 {
122  *index = __atomic_load_n(&rbuf->writeindex, __ATOMIC_RELAXED);
123  return (int32_t) (*index - __atomic_load_n(&rbuf->readindex, __ATOMIC_ACQUIRE));
124 }
125 
137 static inline void
139  void *buffer, uint32_t size,
140  uint32_t offset, const void *data, uint32_t len)
141 {
142  uint32_t l0 = SPA_MIN(len, size - offset), l1 = len - l0;
143  spa_memcpy(SPA_PTROFF(buffer, offset, void), data, l0);
144  if (SPA_UNLIKELY(l1 > 0))
145  spa_memcpy(buffer, SPA_PTROFF(data, l0, void), l1);
146 }
147 
154 static inline void spa_ringbuffer_write_update(struct spa_ringbuffer *rbuf, int32_t index)
155 {
156  __atomic_store_n(&rbuf->writeindex, index, __ATOMIC_RELEASE);
157 }
158 
164 #ifdef __cplusplus
165 } /* extern "C" */
166 #endif
167 
168 #endif /* SPA_RINGBUFFER_H */
spa/utils/defs.h
static 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:61
static void spa_ringbuffer_init(struct spa_ringbuffer *rbuf)
Initialize a spa_ringbuffer with size.
Definition: ringbuffer.h:50
static void spa_ringbuffer_read_update(struct spa_ringbuffer *rbuf, int32_t index)
Update the read pointer to index.
Definition: ringbuffer.h:111
#define SPA_RINGBUFFER_INIT()
Definition: ringbuffer.h:43
static void spa_ringbuffer_write_update(struct spa_ringbuffer *rbuf, int32_t index)
Update the write pointer to index.
Definition: ringbuffer.h:161
static 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:95
static 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:77
static 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:145
static 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:127
#define SPA_MIN(a, b)
Definition: defs.h:147
#define SPA_UNLIKELY(x)
Definition: defs.h:343
#define spa_memcpy(d, s, n)
Definition: defs.h:429
#define SPA_PTROFF(ptr_, offset_, type_)
Return the address (buffer + offset) as pointer of type.
Definition: defs.h:190
spa/utils/string.h
A ringbuffer type.
Definition: ringbuffer.h:37
uint32_t readindex
Definition: ringbuffer.h:38
uint32_t writeindex
Definition: ringbuffer.h:39