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Diffstat (limited to 'third_party/pipewire/spa/utils/ringbuffer.h')
| -rw-r--r-- | third_party/pipewire/spa/utils/ringbuffer.h | 188 |
1 files changed, 188 insertions, 0 deletions
diff --git a/third_party/pipewire/spa/utils/ringbuffer.h b/third_party/pipewire/spa/utils/ringbuffer.h new file mode 100644 index 0000000000..19bfb86755 --- /dev/null +++ b/third_party/pipewire/spa/utils/ringbuffer.h @@ -0,0 +1,188 @@ +/* Simple Plugin API + * + * Copyright © 2018 Wim Taymans + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice (including the next + * paragraph) shall be included in all copies or substantial portions of the + * Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER + * DEALINGS IN THE SOFTWARE. + */ + +#ifndef SPA_RINGBUFFER_H +#define SPA_RINGBUFFER_H + +#ifdef __cplusplus +extern "C" { +#endif + +/** + * \defgroup spa_ringbuffer Ringbuffer + * Ring buffer implementation + */ + +/** + * \addtogroup spa_ringbuffer + * \{ + */ + +struct spa_ringbuffer; + +#include <string.h> + +#include <spa/utils/defs.h> + +/** + * A ringbuffer type. + */ +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 } + +/** + * Initialize a spa_ringbuffer with \a size. + * + * \param rbuf a spa_ringbuffer + */ +static inline void spa_ringbuffer_init(struct spa_ringbuffer *rbuf) +{ + *rbuf = SPA_RINGBUFFER_INIT(); +} + +/** + * Sets the pointers so that the ringbuffer contains \a size bytes. + * + * \param rbuf a spa_ringbuffer + * \param size the target size of \a rbuf + */ +static inline void spa_ringbuffer_set_avail(struct spa_ringbuffer *rbuf, uint32_t size) +{ + rbuf->readindex = 0; + rbuf->writeindex = size; +} + +/** + * Get the read index and available bytes for reading. + * + * \param rbuf a spa_ringbuffer + * \param index the value of readindex, should be taken modulo the size of the + * ringbuffer memory to get the offset in the ringbuffer memory + * \return number of available bytes to read. values < 0 mean + * there was an underrun. values > rbuf->size means there + * was an overrun. + */ +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); +} + +/** + * Read \a len bytes from \a rbuf starting \a offset. \a offset must be taken + * modulo \a size and len should be smaller than \a size. + * + * \param rbuf a struct \ref spa_ringbuffer + * \param buffer memory to read from + * \param size the size of \a buffer + * \param offset offset in \a buffer to read from + * \param data destination memory + * \param len number of bytes to read + */ +static inline void +spa_ringbuffer_read_data(struct spa_ringbuffer *rbuf, + 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); +} + +/** + * Update the read pointer to \a index. + * + * \param rbuf a spa_ringbuffer + * \param index new index + */ +static inline void spa_ringbuffer_read_update(struct spa_ringbuffer *rbuf, int32_t index) +{ + __atomic_store_n(&rbuf->readindex, index, __ATOMIC_RELEASE); +} + +/** + * Get the write index and the number of bytes inside the ringbuffer. + * + * \param rbuf a spa_ringbuffer + * \param index the value of writeindex, should be taken modulo the size of the + * ringbuffer memory to get the offset in the ringbuffer memory + * \return the fill level of \a rbuf. values < 0 mean + * there was an underrun. values > rbuf->size means there + * was an overrun. Subtract from the buffer size to get + * the number of bytes available for writing. + */ +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)); +} + +/** + * Write \a len bytes to \a buffer starting \a offset. \a offset must be taken + * modulo \a size and len should be smaller than \a size. + * + * \param rbuf a spa_ringbuffer + * \param buffer memory to write to + * \param size the size of \a buffer + * \param offset offset in \a buffer to write to + * \param data source memory + * \param len number of bytes to write + */ +static inline void +spa_ringbuffer_write_data(struct spa_ringbuffer *rbuf, + 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); +} + +/** + * Update the write pointer to \a index + * + * \param rbuf a spa_ringbuffer + * \param index new index + */ +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 */ |