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-rw-r--r--pd/portaudio/pablio/ringbuffer.c199
1 files changed, 199 insertions, 0 deletions
diff --git a/pd/portaudio/pablio/ringbuffer.c b/pd/portaudio/pablio/ringbuffer.c
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+/*
+ * $Id: ringbuffer.c,v 1.3 2006-08-07 23:08:10 millerpuckette Exp $
+ * ringbuffer.c
+ * Ring Buffer utility..
+ *
+ * Author: Phil Burk, http://www.softsynth.com
+ *
+ * This program uses the PortAudio Portable Audio Library.
+ * For more information see: http://www.audiomulch.com/portaudio/
+ * 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.
+ *
+ * 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.
+ *
+ * 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.
+ *
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+#include "ringbuffer.h"
+#include <string.h>
+
+/***************************************************************************
+ * Initialize FIFO.
+ * numBytes must be power of 2, returns -1 if not.
+ */
+long RingBuffer_Init( RingBuffer *rbuf, long numBytes, void *dataPtr )
+{
+ if( ((numBytes-1) & numBytes) != 0) return -1; /* Not Power of two. */
+ rbuf->bufferSize = numBytes;
+ rbuf->buffer = (char *)dataPtr;
+ RingBuffer_Flush( rbuf );
+ rbuf->bigMask = (numBytes*2)-1;
+ rbuf->smallMask = (numBytes)-1;
+ return 0;
+}
+/***************************************************************************
+** Return number of bytes available for reading. */
+long RingBuffer_GetReadAvailable( RingBuffer *rbuf )
+{
+ return ( (rbuf->writeIndex - rbuf->readIndex) & rbuf->bigMask );
+}
+/***************************************************************************
+** Return number of bytes available for writing. */
+long RingBuffer_GetWriteAvailable( RingBuffer *rbuf )
+{
+ return ( rbuf->bufferSize - RingBuffer_GetReadAvailable(rbuf));
+}
+
+/***************************************************************************
+** Clear buffer. Should only be called when buffer is NOT being read. */
+void RingBuffer_Flush( RingBuffer *rbuf )
+{
+ rbuf->writeIndex = rbuf->readIndex = 0;
+}
+
+/***************************************************************************
+** Get address of region(s) to which we can write data.
+** If the region is contiguous, size2 will be zero.
+** If non-contiguous, size2 will be the size of second region.
+** Returns room available to be written or numBytes, whichever is smaller.
+*/
+long RingBuffer_GetWriteRegions( RingBuffer *rbuf, long numBytes,
+ void **dataPtr1, long *sizePtr1,
+ void **dataPtr2, long *sizePtr2 )
+{
+ long index;
+ long available = RingBuffer_GetWriteAvailable( rbuf );
+ if( numBytes > available ) numBytes = available;
+ /* Check to see if write is not contiguous. */
+ index = rbuf->writeIndex & rbuf->smallMask;
+ if( (index + numBytes) > rbuf->bufferSize )
+ {
+ /* Write data in two blocks that wrap the buffer. */
+ long firstHalf = rbuf->bufferSize - index;
+ *dataPtr1 = &rbuf->buffer[index];
+ *sizePtr1 = firstHalf;
+ *dataPtr2 = &rbuf->buffer[0];
+ *sizePtr2 = numBytes - firstHalf;
+ }
+ else
+ {
+ *dataPtr1 = &rbuf->buffer[index];
+ *sizePtr1 = numBytes;
+ *dataPtr2 = NULL;
+ *sizePtr2 = 0;
+ }
+ return numBytes;
+}
+
+
+/***************************************************************************
+*/
+long RingBuffer_AdvanceWriteIndex( RingBuffer *rbuf, long numBytes )
+{
+ return rbuf->writeIndex = (rbuf->writeIndex + numBytes) & rbuf->bigMask;
+}
+
+/***************************************************************************
+** Get address of region(s) from which we can read data.
+** If the region is contiguous, size2 will be zero.
+** If non-contiguous, size2 will be the size of second region.
+** Returns room available to be written or numBytes, whichever is smaller.
+*/
+long RingBuffer_GetReadRegions( RingBuffer *rbuf, long numBytes,
+ void **dataPtr1, long *sizePtr1,
+ void **dataPtr2, long *sizePtr2 )
+{
+ long index;
+ long available = RingBuffer_GetReadAvailable( rbuf );
+ if( numBytes > available ) numBytes = available;
+ /* Check to see if read is not contiguous. */
+ index = rbuf->readIndex & rbuf->smallMask;
+ if( (index + numBytes) > rbuf->bufferSize )
+ {
+ /* Write data in two blocks that wrap the buffer. */
+ long firstHalf = rbuf->bufferSize - index;
+ *dataPtr1 = &rbuf->buffer[index];
+ *sizePtr1 = firstHalf;
+ *dataPtr2 = &rbuf->buffer[0];
+ *sizePtr2 = numBytes - firstHalf;
+ }
+ else
+ {
+ *dataPtr1 = &rbuf->buffer[index];
+ *sizePtr1 = numBytes;
+ *dataPtr2 = NULL;
+ *sizePtr2 = 0;
+ }
+ return numBytes;
+}
+/***************************************************************************
+*/
+long RingBuffer_AdvanceReadIndex( RingBuffer *rbuf, long numBytes )
+{
+ return rbuf->readIndex = (rbuf->readIndex + numBytes) & rbuf->bigMask;
+}
+
+/***************************************************************************
+** Return bytes written. */
+long RingBuffer_Write( RingBuffer *rbuf, void *data, long numBytes )
+{
+ long size1, size2, numWritten;
+ void *data1, *data2;
+ numWritten = RingBuffer_GetWriteRegions( rbuf, numBytes, &data1, &size1, &data2, &size2 );
+ if( size2 > 0 )
+ {
+
+ memcpy( data1, data, size1 );
+ data = ((char *)data) + size1;
+ memcpy( data2, data, size2 );
+ }
+ else
+ {
+ memcpy( data1, data, size1 );
+ }
+ RingBuffer_AdvanceWriteIndex( rbuf, numWritten );
+ return numWritten;
+}
+
+/***************************************************************************
+** Return bytes read. */
+long RingBuffer_Read( RingBuffer *rbuf, void *data, long numBytes )
+{
+ long size1, size2, numRead;
+ void *data1, *data2;
+ numRead = RingBuffer_GetReadRegions( rbuf, numBytes, &data1, &size1, &data2, &size2 );
+ if( size2 > 0 )
+ {
+ memcpy( data, data1, size1 );
+ data = ((char *)data) + size1;
+ memcpy( data, data2, size2 );
+ }
+ else
+ {
+ memcpy( data, data1, size1 );
+ }
+ RingBuffer_AdvanceReadIndex( rbuf, numRead );
+ return numRead;
+}