Locate and position the current Audacity source code, and clear a variety of old junk out of the way into junk-branches

src/RingBuffer.cpp

@@ -0,0 +1,155 @@
+/**********************************************************************
+
+  Audacity: A Digital Audio Editor
+
+  RingBuffer.cpp
+
+  Dominic Mazzoni
+
+*******************************************************************//*!
+
+\class RingBuffer
+\brief Holds streamed audio samples.
+
+  This class is thread-safe, assuming that there is only one
+  thread writing, and one thread reading.  If two threads both
+  need to read, or both need to write, they need to lock this
+  class from outside using their own mutex.
+
+  AvailForPut and AvailForGet may underestimate but will never
+  overestimate.
+
+*//*******************************************************************/
+
+
+#include "RingBuffer.h"
+
+RingBuffer::RingBuffer(sampleFormat format, int size)
+{
+   mFormat = format;
+   mBufferSize = (size > 64? size: 64);
+   mStart = 0;
+   mEnd = 0;
+   mBuffer = NewSamples(mBufferSize, mFormat);
+}
+
+RingBuffer::~RingBuffer()
+{
+   DeleteSamples(mBuffer);
+}
+
+int RingBuffer::Len()
+{
+   return (mEnd + mBufferSize - mStart) % mBufferSize;
+}
+
+//
+// For the writer only:
+//
+
+int RingBuffer::AvailForPut()
+{
+   return (mBufferSize-4) - Len();
+}
+
+int RingBuffer::Put(samplePtr buffer, sampleFormat format,
+                    int samplesToCopy)
+{
+   samplePtr src;
+   int block;
+   int copied;
+   int pos;
+   int len = Len();
+
+   if (samplesToCopy > (mBufferSize-4) - len)
+      samplesToCopy = (mBufferSize-4) - len;
+
+   src = buffer;
+   copied = 0;
+   pos = mEnd;
+
+   while(samplesToCopy) {
+      block = samplesToCopy;
+      if (block > mBufferSize - pos)
+         block = mBufferSize - pos;
+      
+      CopySamples(src, format,
+                  mBuffer + pos * SAMPLE_SIZE(mFormat), mFormat,
+                  block);
+
+      src += block * SAMPLE_SIZE(format);
+      pos = (pos + block) % mBufferSize;
+      samplesToCopy -= block;
+      copied += block;
+   }
+
+   mEnd = pos;
+
+   return copied;
+}
+
+//
+// For the reader only:
+//
+
+int RingBuffer::AvailForGet()
+{
+   return Len();
+}
+
+int RingBuffer::Get(samplePtr buffer, sampleFormat format,
+                    int samplesToCopy)
+{
+   samplePtr dest;
+   int block;
+   int copied;
+   int len = Len();
+
+   if (samplesToCopy > len)
+      samplesToCopy = len;
+
+   dest = buffer;
+   copied = 0;
+
+   while(samplesToCopy) {
+      block = samplesToCopy;
+      if (block > mBufferSize - mStart)
+         block = mBufferSize - mStart;
+
+      CopySamples(mBuffer + mStart * SAMPLE_SIZE(mFormat), mFormat,
+                  dest, format,
+                  block);
+
+      dest += block * SAMPLE_SIZE(mFormat);
+      mStart = (mStart + block) % mBufferSize;
+      samplesToCopy -= block;
+      copied += block;
+   }
+
+   return copied;
+}
+
+int RingBuffer::Discard(int samplesToDiscard)
+{
+   int len = Len();
+
+   if (samplesToDiscard > len)
+      samplesToDiscard = len;
+
+   mStart = (mStart + samplesToDiscard) % mBufferSize;
+
+   return samplesToDiscard;
+}
+
+
+// Indentation settings for Vim and Emacs and unique identifier for Arch, a
+// version control system. Please do not modify past this point.
+//
+// Local Variables:
+// c-basic-offset: 3
+// indent-tabs-mode: nil
+// End:
+//
+// vim: et sts=3 sw=3
+// arch-tag: 06ad2130-a0c4-4fa5-a236-f76008a6d92a
+