pa_ringbuffer.c File Reference

#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "webrtc/modules/audio_device/mac/portaudio/pa_memorybarrier.h"
#include "webrtc/modules/audio_device/mac/portaudio/pa_ringbuffer.h"

Functions
PaRingBufferSize	PaUtil_InitializeRingBuffer (PaUtilRingBuffer *rbuf, PaRingBufferSize elementSizeBytes, PaRingBufferSize elementCount, void *dataPtr)
PaRingBufferSize	PaUtil_GetRingBufferReadAvailable (PaUtilRingBuffer *rbuf)
PaRingBufferSize	PaUtil_GetRingBufferWriteAvailable (PaUtilRingBuffer *rbuf)
void	PaUtil_FlushRingBuffer (PaUtilRingBuffer *rbuf)
PaRingBufferSize	PaUtil_GetRingBufferWriteRegions (PaUtilRingBuffer *rbuf, PaRingBufferSize elementCount, void **dataPtr1, PaRingBufferSize *sizePtr1, void **dataPtr2, PaRingBufferSize *sizePtr2)
PaRingBufferSize	PaUtil_AdvanceRingBufferWriteIndex (PaUtilRingBuffer *rbuf, PaRingBufferSize elementCount)
PaRingBufferSize	PaUtil_GetRingBufferReadRegions (PaUtilRingBuffer *rbuf, PaRingBufferSize elementCount, void **dataPtr1, PaRingBufferSize *sizePtr1, void **dataPtr2, PaRingBufferSize *sizePtr2)
PaRingBufferSize	PaUtil_AdvanceRingBufferReadIndex (PaUtilRingBuffer *rbuf, PaRingBufferSize elementCount)
PaRingBufferSize	PaUtil_WriteRingBuffer (PaUtilRingBuffer *rbuf, const void *data, PaRingBufferSize elementCount)
PaRingBufferSize	PaUtil_ReadRingBuffer (PaUtilRingBuffer *rbuf, void *data, PaRingBufferSize elementCount)

Function Documentation

PaUtil_AdvanceRingBufferReadIndex()

PaRingBufferSize PaUtil_AdvanceRingBufferReadIndex	(	PaUtilRingBuffer *	rbuf,
		PaRingBufferSize	elementCount
	)

Advance the read index to the next location to be read.

Parameters

rbuf	The ring buffer.
elementCount	The number of elements to advance.

Returns

The new position.

PaUtil_AdvanceRingBufferWriteIndex()

PaRingBufferSize PaUtil_AdvanceRingBufferWriteIndex	(	PaUtilRingBuffer *	rbuf,
		PaRingBufferSize	elementCount
	)

Advance the write index to the next location to be written.

Parameters

rbuf	The ring buffer.
elementCount	The number of elements to advance.

Returns

The new position.

PaUtil_FlushRingBuffer()

void PaUtil_FlushRingBuffer

(

PaUtilRingBuffer *

rbuf

)

Clear buffer. Should only be called when buffer is NOT being read.

Parameters

rbuf	The ring buffer.

PaUtil_GetRingBufferReadAvailable()

PaRingBufferSize PaUtil_GetRingBufferReadAvailable

(

PaUtilRingBuffer *

rbuf

)

Retrieve the number of elements available in the ring buffer for reading.

Parameters

rbuf	The ring buffer.

Returns

The number of elements available for reading.

PaUtil_GetRingBufferReadRegions()

PaRingBufferSize PaUtil_GetRingBufferReadRegions	(	PaUtilRingBuffer *	rbuf,
		PaRingBufferSize	elementCount,
		void **	dataPtr1,
		PaRingBufferSize *	sizePtr1,
		void **	dataPtr2,
		PaRingBufferSize *	sizePtr2
	)

Get address of region(s) from which we can write data.

Parameters

rbuf	The ring buffer.
elementCount	The number of elements desired.
dataPtr1	The address where the first (or only) region pointer will be stored.
sizePtr1	The address where the first (or only) region length will be stored.
dataPtr2	The address where the second region pointer will be stored if the first region is too small to satisfy elementCount.
sizePtr2	The address where the second region length will be stored if the first region is too small to satisfy elementCount.

Returns

The number of elements available for reading.

PaUtil_GetRingBufferWriteAvailable()

PaRingBufferSize PaUtil_GetRingBufferWriteAvailable

(

PaUtilRingBuffer *

rbuf

)

Retrieve the number of elements available in the ring buffer for writing.

Parameters

rbuf	The ring buffer.

Returns

The number of elements available for writing.

PaUtil_GetRingBufferWriteRegions()

PaRingBufferSize PaUtil_GetRingBufferWriteRegions	(	PaUtilRingBuffer *	rbuf,
		PaRingBufferSize	elementCount,
		void **	dataPtr1,
		PaRingBufferSize *	sizePtr1,
		void **	dataPtr2,
		PaRingBufferSize *	sizePtr2
	)

Get address of region(s) to which we can write data.

Parameters

rbuf	The ring buffer.
elementCount	The number of elements desired.
dataPtr1	The address where the first (or only) region pointer will be stored.
sizePtr1	The address where the first (or only) region length will be stored.
dataPtr2	The address where the second region pointer will be stored if the first region is too small to satisfy elementCount.
sizePtr2	The address where the second region length will be stored if the first region is too small to satisfy elementCount.

Returns

The room available to be written or elementCount, whichever is smaller.

PaUtil_InitializeRingBuffer()

PaRingBufferSize PaUtil_InitializeRingBuffer	(	PaUtilRingBuffer *	rbuf,
		PaRingBufferSize	elementSizeBytes,
		PaRingBufferSize	elementCount,
		void *	dataPtr
	)

Initialize Ring Buffer.

Parameters

rbuf	The ring buffer.
elementSizeBytes	The size of a single data element in bytes.
elementCount	The number of elements in the buffer (must be power of 2).
dataPtr	A pointer to a previously allocated area where the data will be maintained. It must be elementCount*elementSizeBytes long.

Returns

-1 if elementCount is not a power of 2, otherwise 0.

PaUtil_ReadRingBuffer()

PaRingBufferSize PaUtil_ReadRingBuffer	(	PaUtilRingBuffer *	rbuf,
		void *	data,
		PaRingBufferSize	elementCount
	)

Read data from the ring buffer.

Parameters

rbuf	The ring buffer.
data	The address where the data should be stored.
elementCount	The number of elements to be read.

Returns

The number of elements read.

PaUtil_WriteRingBuffer()

PaRingBufferSize PaUtil_WriteRingBuffer	(	PaUtilRingBuffer *	rbuf,
		const void *	data,
		PaRingBufferSize	elementCount
	)

Write data to the ring buffer.

Parameters

rbuf	The ring buffer.
data	The address of new data to write to the buffer.
elementCount	The number of elements to be written.

Returns

The number of elements written.