pa_ringbuffer.c File Reference

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

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

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Detailed Description

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Function Documentation

long PaUtil_AdvanceRingBufferReadIndex	(	PaUtilRingBuffer *	rbuf,
		long	numBytes
	)

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

Parameters:

	rbuf	The ring buffer.
	numBytes	The number of bytes to advance.

Returns:

The new position.

long PaUtil_AdvanceRingBufferWriteIndex	(	PaUtilRingBuffer *	rbuf,
		long	numBytes
	)

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

Parameters:

	rbuf	The ring buffer.
	numBytes	The number of bytes to advance.

Returns:

The new position.

void PaUtil_FlushRingBuffer

(

PaUtilRingBuffer *

rbuf

)

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

Parameters:

rbuf

The ring buffer.

long PaUtil_GetRingBufferReadAvailable

(

PaUtilRingBuffer *

rbuf

)

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

Parameters:

rbuf

The ring buffer.

Returns:

The number of bytes available for reading.

long PaUtil_GetRingBufferReadRegions	(	PaUtilRingBuffer *	rbuf,
		long	numBytes,
		void **	dataPtr1,
		long *	sizePtr1,
		void **	dataPtr2,
		long *	sizePtr2
	)

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

Parameters:

	rbuf	The ring buffer.
	numBytes	The number of bytes 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 numBytes.
	sizePtr2	The address where the second region length will be stored if the first region is too small to satisfy numBytes.

Returns:

The number of bytes available for reading.

long PaUtil_GetRingBufferWriteAvailable

(

PaUtilRingBuffer *

rbuf

)

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

Parameters:

rbuf

The ring buffer.

Returns:

The number of bytes available for writing.

long PaUtil_GetRingBufferWriteRegions	(	PaUtilRingBuffer *	rbuf,
		long	numBytes,
		void **	dataPtr1,
		long *	sizePtr1,
		void **	dataPtr2,
		long *	sizePtr2
	)

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

Parameters:

	rbuf	The ring buffer.
	numBytes	The number of bytes 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 numBytes.
	sizePtr2	The address where the second region length will be stored if the first region is too small to satisfy numBytes.

Returns:

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

long PaUtil_InitializeRingBuffer	(	PaUtilRingBuffer *	rbuf,
		long	numBytes,
		void *	dataPtr
	)

Initialize Ring Buffer.

Parameters:

	rbuf	The ring buffer.
	numBytes	The number of bytes in the buffer and must be power of 2.
	dataPtr	A pointer to a previously allocated area where the data will be maintained. It must be numBytes long.

Returns:

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

long PaUtil_ReadRingBuffer	(	PaUtilRingBuffer *	rbuf,
		void *	data,
		long	numBytes
	)

Read data from the ring buffer.

Parameters:

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

Returns:

The number of bytes read.

long PaUtil_WriteRingBuffer	(	PaUtilRingBuffer *	rbuf,
		const void *	data,
		long	numBytes
	)

Write data to the ring buffer.

Parameters:

	rbuf	The ring buffer.
	data	The address of new data to write to the buffer.
	numBytes	The number of bytes to be written.

Returns:

The number of bytes written.

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