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ringbuffer.h
Go to the documentation of this file.
/* Simple Plugin API */
/* SPDX-FileCopyrightText: Copyright © 2018 Wim Taymans */
/* SPDX-License-Identifier: MIT */
#ifndef SPA_RINGBUFFER_H
#define SPA_RINGBUFFER_H
#ifdef __cplusplus
extern "C" {
#endif
struct spa_ringbuffer;
#include <string.h>
#include <spa/utils/defs.h>
struct spa_ringbuffer {
uint32_t readindex; /*< the current read index */
uint32_t writeindex; /*< the current write index */
};
#define SPA_RINGBUFFER_INIT() ((struct spa_ringbuffer) { 0, 0 })
static inline void spa_ringbuffer_init(struct spa_ringbuffer *rbuf)
{
*rbuf = SPA_RINGBUFFER_INIT();
}
static inline void spa_ringbuffer_set_avail(struct spa_ringbuffer *rbuf, uint32_t size)
{
rbuf->readindex = 0;
rbuf->writeindex = size;
}
static inline int32_t spa_ringbuffer_get_read_index(struct spa_ringbuffer *rbuf, uint32_t *index)
{
*index = __atomic_load_n(&rbuf->readindex, __ATOMIC_RELAXED);
return (int32_t) (__atomic_load_n(&rbuf->writeindex, __ATOMIC_ACQUIRE) - *index);
}
static inline void
spa_ringbuffer_read_data(struct spa_ringbuffer *rbuf SPA_UNUSED,
const void *buffer, uint32_t size,
uint32_t offset, void *data, uint32_t len)
{
uint32_t l0 = SPA_MIN(len, size - offset), l1 = len - l0;
spa_memcpy(data, SPA_PTROFF(buffer, offset, void), l0);
if (SPA_UNLIKELY(l1 > 0))
spa_memcpy(SPA_PTROFF(data, l0, void), buffer, l1);
}
static inline void spa_ringbuffer_read_update(struct spa_ringbuffer *rbuf, int32_t index)
{
__atomic_store_n(&rbuf->readindex, index, __ATOMIC_RELEASE);
}
static inline int32_t spa_ringbuffer_get_write_index(struct spa_ringbuffer *rbuf, uint32_t *index)
{
*index = __atomic_load_n(&rbuf->writeindex, __ATOMIC_RELAXED);
return (int32_t) (*index - __atomic_load_n(&rbuf->readindex, __ATOMIC_ACQUIRE));
}
static inline void
spa_ringbuffer_write_data(struct spa_ringbuffer *rbuf SPA_UNUSED,
void *buffer, uint32_t size,
uint32_t offset, const void *data, uint32_t len)
{
uint32_t l0 = SPA_MIN(len, size - offset), l1 = len - l0;
spa_memcpy(SPA_PTROFF(buffer, offset, void), data, l0);
if (SPA_UNLIKELY(l1 > 0))
spa_memcpy(buffer, SPA_PTROFF(data, l0, void), l1);
}
static inline void spa_ringbuffer_write_update(struct spa_ringbuffer *rbuf, int32_t index)
{
__atomic_store_n(&rbuf->writeindex, index, __ATOMIC_RELEASE);
}
#ifdef __cplusplus
} /* extern "C" */
#endif
#endif /* SPA_RINGBUFFER_H */
defs.h
spa/utils/defs.h
spa_ringbuffer_set_avail
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
spa_ringbuffer_init
static void spa_ringbuffer_init(struct spa_ringbuffer *rbuf)
Initialize a spa_ringbuffer with size.
Definition ringbuffer.h:50
spa_ringbuffer_read_update
static void spa_ringbuffer_read_update(struct spa_ringbuffer *rbuf, int32_t index)
Update the read pointer to index.
Definition ringbuffer.h:111
SPA_RINGBUFFER_INIT
#define SPA_RINGBUFFER_INIT()
Definition ringbuffer.h:43
spa_ringbuffer_write_update
static void spa_ringbuffer_write_update(struct spa_ringbuffer *rbuf, int32_t index)
Update the write pointer to index.
Definition ringbuffer.h:161
spa_ringbuffer_read_data
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
spa_ringbuffer_get_read_index
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
spa_ringbuffer_write_data
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
spa_ringbuffer_get_write_index
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
SPA_MIN
#define SPA_MIN(a, b)
Definition defs.h:151
SPA_UNUSED
#define SPA_UNUSED
Definition defs.h:289
SPA_UNLIKELY
#define SPA_UNLIKELY(x)
Definition defs.h:351
spa_memcpy
#define spa_memcpy(d, s, n)
Definition defs.h:437
SPA_PTROFF
#define SPA_PTROFF(ptr_, offset_, type_)
Return the address (buffer + offset) as pointer of type.
Definition defs.h:198
string.h
spa/utils/string.h
spa_ringbuffer
A ringbuffer type.
Definition ringbuffer.h:37
spa_ringbuffer::readindex
uint32_t readindex
Definition ringbuffer.h:38
spa_ringbuffer::writeindex
uint32_t writeindex
Definition ringbuffer.h:39