pa_ringbuffer.c File Reference

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include "pa_ringbuffer.h"
#include <string.h>
#include "pa_memorybarrier.h"

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

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Detailed Description

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Function Documentation

long PaUtil_AdvanceRingBufferReadIndex	(	PaUtilRingBuffer *	rbuf,
		long	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.

References PaUtilRingBuffer::bigMask, and PaUtilRingBuffer::readIndex.

Referenced by PaUtil_ReadRingBuffer().

long PaUtil_AdvanceRingBufferWriteIndex	(	PaUtilRingBuffer *	rbuf,
		long	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.

References PaUtilRingBuffer::bigMask, and PaUtilRingBuffer::writeIndex.

Referenced by PaUtil_WriteRingBuffer(), and resetBlioRingBuffers().

void PaUtil_FlushRingBuffer

(

PaUtilRingBuffer *

rbuf

)

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

Parameters:

rbuf

The ring buffer.

References PaUtilRingBuffer::readIndex, and PaUtilRingBuffer::writeIndex.

Referenced by PaUtil_InitializeRingBuffer(), and resetBlioRingBuffers().

long 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.

References PaUtilRingBuffer::bigMask, PaUtilRingBuffer::readIndex, and PaUtilRingBuffer::writeIndex.

Referenced by BlioCallback(), GetStreamReadAvailable(), PaUtil_GetRingBufferReadRegions(), PaUtil_GetRingBufferWriteAvailable(), and ReadStream().

long PaUtil_GetRingBufferReadRegions	(	PaUtilRingBuffer *	rbuf,
		long	elementCount,
		void **	dataPtr1,
		long *	sizePtr1,
		void **	dataPtr2,
		long *	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.

References PaUtilRingBuffer::buffer, PaUtilRingBuffer::bufferSize, PaUtilRingBuffer::elementSizeBytes, PaUtil_GetRingBufferReadAvailable(), PaUtilRingBuffer::readIndex, and PaUtilRingBuffer::smallMask.

Referenced by PaUtil_ReadRingBuffer().

long 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.

References PaUtilRingBuffer::bufferSize, and PaUtil_GetRingBufferReadAvailable().

Referenced by BlioCallback(), GetStreamWriteAvailable(), PaUtil_GetRingBufferWriteRegions(), waitUntilBlioWriteBufferIsFlushed(), and WriteStream().

long PaUtil_GetRingBufferWriteRegions	(	PaUtilRingBuffer *	rbuf,
		long	elementCount,
		void **	dataPtr1,
		long *	sizePtr1,
		void **	dataPtr2,
		long *	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.

References PaUtilRingBuffer::buffer, PaUtilRingBuffer::bufferSize, PaUtilRingBuffer::elementSizeBytes, PaUtil_GetRingBufferWriteAvailable(), PaUtilRingBuffer::smallMask, and PaUtilRingBuffer::writeIndex.

Referenced by PaUtil_WriteRingBuffer().

long PaUtil_InitializeRingBuffer	(	PaUtilRingBuffer *	rbuf,
		long	elementSizeBytes,
		long	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.

References PaUtilRingBuffer::bigMask, PaUtilRingBuffer::buffer, PaUtilRingBuffer::bufferSize, PaUtilRingBuffer::elementSizeBytes, PaUtil_FlushRingBuffer(), and PaUtilRingBuffer::smallMask.

Referenced by initializeBlioRingBuffers().

long PaUtil_ReadRingBuffer	(	PaUtilRingBuffer *	rbuf,
		void *	data,
		long	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.

References PaUtilRingBuffer::elementSizeBytes, PaUtil_AdvanceRingBufferReadIndex(), and PaUtil_GetRingBufferReadRegions().

Referenced by BlioCallback(), and ReadStream().

long PaUtil_WriteRingBuffer	(	PaUtilRingBuffer *	rbuf,
		const void *	data,
		long	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.

References PaUtilRingBuffer::elementSizeBytes, PaUtil_AdvanceRingBufferWriteIndex(), and PaUtil_GetRingBufferWriteRegions().

Referenced by BlioCallback(), and WriteStream().