PipeWire  0.3.45
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
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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:
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12  * The above copyright notice and this permission notice (including the next
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14  * Software.
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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,
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23  */
24 
25 #ifndef SPA_RINGBUFFER_H
26 #define SPA_RINGBUFFER_H
27 
28 #ifdef __cplusplus
29 extern "C" {
30 #endif
31 
42 struct spa_ringbuffer;
43 
44 #include <string.h>
45 
46 #include <spa/utils/defs.h>
47 
51 struct spa_ringbuffer {
52  uint32_t readindex; /*< the current read index */
53  uint32_t writeindex; /*< the current write index */
54 };
55 
56 #define SPA_RINGBUFFER_INIT() (struct spa_ringbuffer) { 0, 0 }
57 
63 static inline void spa_ringbuffer_init(struct spa_ringbuffer *rbuf)
64 {
65  *rbuf = SPA_RINGBUFFER_INIT();
66 }
67 
74 static inline void spa_ringbuffer_set_avail(struct spa_ringbuffer *rbuf, uint32_t size)
75 {
76  rbuf->readindex = 0;
77  rbuf->writeindex = size;
78 }
79 
90 static inline int32_t spa_ringbuffer_get_read_index(struct spa_ringbuffer *rbuf, uint32_t *index)
91 {
92  *index = __atomic_load_n(&rbuf->readindex, __ATOMIC_RELAXED);
93  return (int32_t) (__atomic_load_n(&rbuf->writeindex, __ATOMIC_ACQUIRE) - *index);
94 }
95 
107 static inline void
109  const void *buffer, uint32_t size,
110  uint32_t offset, void *data, uint32_t len)
111 {
112  uint32_t l0 = SPA_MIN(len, size - offset), l1 = len - l0;
113  spa_memcpy(data, SPA_PTROFF(buffer, offset, void), l0);
114  if (SPA_UNLIKELY(l1 > 0))
115  spa_memcpy(SPA_PTROFF(data, l0, void), buffer, l1);
116 }
117 
124 static inline void spa_ringbuffer_read_update(struct spa_ringbuffer *rbuf, int32_t index)
125 {
126  __atomic_store_n(&rbuf->readindex, index, __ATOMIC_RELEASE);
127 }
128 
140 static inline int32_t spa_ringbuffer_get_write_index(struct spa_ringbuffer *rbuf, uint32_t *index)
141 {
142  *index = __atomic_load_n(&rbuf->writeindex, __ATOMIC_RELAXED);
143  return (int32_t) (*index - __atomic_load_n(&rbuf->readindex, __ATOMIC_ACQUIRE));
144 }
145 
157 static inline void
159  void *buffer, uint32_t size,
160  uint32_t offset, const void *data, uint32_t len)
161 {
162  uint32_t l0 = SPA_MIN(len, size - offset), l1 = len - l0;
163  spa_memcpy(SPA_PTROFF(buffer, offset, void), data, l0);
164  if (SPA_UNLIKELY(l1 > 0))
165  spa_memcpy(buffer, SPA_PTROFF(data, l0, void), l1);
166 }
167 
174 static inline void spa_ringbuffer_write_update(struct spa_ringbuffer *rbuf, int32_t index)
175 {
176  __atomic_store_n(&rbuf->writeindex, index, __ATOMIC_RELEASE);
177 }
178 
184 #ifdef __cplusplus
185 } /* extern "C" */
186 #endif
187 
188 #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:81
static void spa_ringbuffer_init(struct spa_ringbuffer *rbuf)
Initialize a spa_ringbuffer with size.
Definition: ringbuffer.h:70
static void spa_ringbuffer_read_update(struct spa_ringbuffer *rbuf, int32_t index)
Update the read pointer to index.
Definition: ringbuffer.h:131
#define SPA_RINGBUFFER_INIT()
Definition: ringbuffer.h:63
static void spa_ringbuffer_write_update(struct spa_ringbuffer *rbuf, int32_t index)
Update the write pointer to index.
Definition: ringbuffer.h:181
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:115
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:97
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:165
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:147
#define SPA_MIN(a, b)
Definition: defs.h:146
#define SPA_UNLIKELY(x)
Definition: defs.h:315
#define spa_memcpy(d, s, n)
Definition: defs.h:401
#define SPA_PTROFF(ptr_, offset_, type_)
Return the address (buffer + offset) as pointer of type.
Definition: defs.h:183
spa/utils/string.h
A ringbuffer type.
Definition: ringbuffer.h:57
uint32_t readindex
Definition: ringbuffer.h:58
uint32_t writeindex
Definition: ringbuffer.h:59