| #ifndef WEBRTC_AUDIO_DEVICE_PA_RINGBUFFER_H |
| #define WEBRTC_AUDIO_DEVICE_PA_RINGBUFFER_H |
| /* |
| * $Id: pa_ringbuffer.h 1421 2009-11-18 16:09:05Z bjornroche $ |
| * Portable Audio I/O Library |
| * Ring Buffer utility. |
| * |
| * Author: Phil Burk, http://www.softsynth.com |
| * modified for SMP safety on OS X by Bjorn Roche. |
| * also allowed for const where possible. |
| * modified for multiple-byte-sized data elements by Sven Fischer |
| * |
| * Note that this is safe only for a single-thread reader |
| * and a single-thread writer. |
| * |
| * This program is distributed with the PortAudio Portable Audio Library. |
| * For more information see: http://www.portaudio.com |
| * Copyright (c) 1999-2000 Ross Bencina and Phil Burk |
| * |
| * 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 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. |
| */ |
| |
| /* |
| * The text above constitutes the entire PortAudio license; however, |
| * the PortAudio community also makes the following non-binding requests: |
| * |
| * Any person wishing to distribute modifications to the Software is |
| * requested to send the modifications to the original developer so that |
| * they can be incorporated into the canonical version. It is also |
| * requested that these non-binding requests be included along with the |
| * license above. |
| */ |
| |
| /** @file |
| @ingroup common_src |
| @brief Single-reader single-writer lock-free ring buffer |
| |
| PaUtilRingBuffer is a ring buffer used to transport samples between |
| different execution contexts (threads, OS callbacks, interrupt handlers) |
| without requiring the use of any locks. This only works when there is |
| a single reader and a single writer (ie. one thread or callback writes |
| to the ring buffer, another thread or callback reads from it). |
| |
| The PaUtilRingBuffer structure manages a ring buffer containing N |
| elements, where N must be a power of two. An element may be any size |
| (specified in bytes). |
| |
| The memory area used to store the buffer elements must be allocated by |
| the client prior to calling PaUtil_InitializeRingBuffer() and must outlive |
| the use of the ring buffer. |
| */ |
| |
| #if defined(__APPLE__) |
| #include <sys/types.h> |
| typedef int32_t PaRingBufferSize; |
| #elif defined( __GNUC__ ) |
| typedef long PaRingBufferSize; |
| #elif (_MSC_VER >= 1400) |
| typedef long PaRingBufferSize; |
| #elif defined(_MSC_VER) || defined(__BORLANDC__) |
| typedef long PaRingBufferSize; |
| #else |
| typedef long PaRingBufferSize; |
| #endif |
| |
| |
| |
| #ifdef __cplusplus |
| extern "C" |
| { |
| #endif /* __cplusplus */ |
| |
| typedef struct PaUtilRingBuffer |
| { |
| PaRingBufferSize bufferSize; /**< Number of elements in FIFO. Power of 2. Set by PaUtil_InitRingBuffer. */ |
| PaRingBufferSize writeIndex; /**< Index of next writable element. Set by PaUtil_AdvanceRingBufferWriteIndex. */ |
| PaRingBufferSize readIndex; /**< Index of next readable element. Set by PaUtil_AdvanceRingBufferReadIndex. */ |
| PaRingBufferSize bigMask; /**< Used for wrapping indices with extra bit to distinguish full/empty. */ |
| PaRingBufferSize smallMask; /**< Used for fitting indices to buffer. */ |
| PaRingBufferSize elementSizeBytes; /**< Number of bytes per element. */ |
| char *buffer; /**< Pointer to the buffer containing the actual data. */ |
| }PaUtilRingBuffer; |
| |
| /** Initialize Ring Buffer. |
| |
| @param rbuf The ring buffer. |
| |
| @param elementSizeBytes The size of a single data element in bytes. |
| |
| @param elementCount The number of elements in the buffer (must be power of 2). |
| |
| @param dataPtr A pointer to a previously allocated area where the data |
| will be maintained. It must be elementCount*elementSizeBytes long. |
| |
| @return -1 if elementCount is not a power of 2, otherwise 0. |
| */ |
| PaRingBufferSize PaUtil_InitializeRingBuffer( PaUtilRingBuffer *rbuf, PaRingBufferSize elementSizeBytes, PaRingBufferSize elementCount, void *dataPtr ); |
| |
| /** Clear buffer. Should only be called when buffer is NOT being read. |
| |
| @param rbuf The ring buffer. |
| */ |
| void PaUtil_FlushRingBuffer( PaUtilRingBuffer *rbuf ); |
| |
| /** Retrieve the number of elements available in the ring buffer for writing. |
| |
| @param rbuf The ring buffer. |
| |
| @return The number of elements available for writing. |
| */ |
| PaRingBufferSize PaUtil_GetRingBufferWriteAvailable( PaUtilRingBuffer *rbuf ); |
| |
| /** Retrieve the number of elements available in the ring buffer for reading. |
| |
| @param rbuf The ring buffer. |
| |
| @return The number of elements available for reading. |
| */ |
| PaRingBufferSize PaUtil_GetRingBufferReadAvailable( PaUtilRingBuffer *rbuf ); |
| |
| /** Write data to the ring buffer. |
| |
| @param rbuf The ring buffer. |
| |
| @param data The address of new data to write to the buffer. |
| |
| @param elementCount The number of elements to be written. |
| |
| @return The number of elements written. |
| */ |
| PaRingBufferSize PaUtil_WriteRingBuffer( PaUtilRingBuffer *rbuf, const void *data, PaRingBufferSize elementCount ); |
| |
| /** Read data from the ring buffer. |
| |
| @param rbuf The ring buffer. |
| |
| @param data The address where the data should be stored. |
| |
| @param elementCount The number of elements to be read. |
| |
| @return The number of elements read. |
| */ |
| PaRingBufferSize PaUtil_ReadRingBuffer( PaUtilRingBuffer *rbuf, void *data, PaRingBufferSize elementCount ); |
| |
| /** Get address of region(s) to which we can write data. |
| |
| @param rbuf The ring buffer. |
| |
| @param elementCount The number of elements desired. |
| |
| @param dataPtr1 The address where the first (or only) region pointer will be |
| stored. |
| |
| @param sizePtr1 The address where the first (or only) region length will be |
| stored. |
| |
| @param dataPtr2 The address where the second region pointer will be stored if |
| the first region is too small to satisfy elementCount. |
| |
| @param sizePtr2 The address where the second region length will be stored if |
| the first region is too small to satisfy elementCount. |
| |
| @return The room available to be written or elementCount, whichever is smaller. |
| */ |
| PaRingBufferSize PaUtil_GetRingBufferWriteRegions( PaUtilRingBuffer *rbuf, PaRingBufferSize elementCount, |
| void **dataPtr1, PaRingBufferSize *sizePtr1, |
| void **dataPtr2, PaRingBufferSize *sizePtr2 ); |
| |
| /** Advance the write index to the next location to be written. |
| |
| @param rbuf The ring buffer. |
| |
| @param elementCount The number of elements to advance. |
| |
| @return The new position. |
| */ |
| PaRingBufferSize PaUtil_AdvanceRingBufferWriteIndex( PaUtilRingBuffer *rbuf, PaRingBufferSize elementCount ); |
| |
| /** Get address of region(s) from which we can write data. |
| |
| @param rbuf The ring buffer. |
| |
| @param elementCount The number of elements desired. |
| |
| @param dataPtr1 The address where the first (or only) region pointer will be |
| stored. |
| |
| @param sizePtr1 The address where the first (or only) region length will be |
| stored. |
| |
| @param dataPtr2 The address where the second region pointer will be stored if |
| the first region is too small to satisfy elementCount. |
| |
| @param sizePtr2 The address where the second region length will be stored if |
| the first region is too small to satisfy elementCount. |
| |
| @return The number of elements available for reading. |
| */ |
| PaRingBufferSize PaUtil_GetRingBufferReadRegions( PaUtilRingBuffer *rbuf, PaRingBufferSize elementCount, |
| void **dataPtr1, PaRingBufferSize *sizePtr1, |
| void **dataPtr2, PaRingBufferSize *sizePtr2 ); |
| |
| /** Advance the read index to the next location to be read. |
| |
| @param rbuf The ring buffer. |
| |
| @param elementCount The number of elements to advance. |
| |
| @return The new position. |
| */ |
| PaRingBufferSize PaUtil_AdvanceRingBufferReadIndex( PaUtilRingBuffer *rbuf, PaRingBufferSize elementCount ); |
| |
| #ifdef __cplusplus |
| } |
| #endif /* __cplusplus */ |
| #endif /* MODULES_AUDIO_DEVICE_MAIN_SOURCE_MAC_PORTAUDIO_PA_RINGBUFFER_H_ */ |