Revert of Introduce PushPullFIFO class and remove other FIFOs

third_party/WebKit/Source/platform/audio/AudioFIFO.h

Index: third_party/WebKit/Source/platform/audio/AudioFIFO.h
diff --git a/third_party/WebKit/Source/platform/audio/AudioFIFO.h b/third_party/WebKit/Source/platform/audio/AudioFIFO.h
new file mode 100644
index 0000000000000000000000000000000000000000..ef66f92a98521d0127bff757ecaafb75beaaaed1
--- /dev/null
+++ b/third_party/WebKit/Source/platform/audio/AudioFIFO.h
@@ -0,0 +1,84 @@
+/*
+ * Copyright (C) 2012 Google Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1.  Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ * 2.  Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
+ *     its contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef AudioFIFO_h
+#define AudioFIFO_h
+
+#include "platform/audio/AudioBus.h"
+#include "wtf/Allocator.h"
+
+namespace blink {
+
+class AudioFIFO {
+  USING_FAST_MALLOC(AudioFIFO);
+  WTF_MAKE_NONCOPYABLE(AudioFIFO);
+
+ public:
+  // Create a FIFO large enough to hold |fifoLength| frames of data of
+  // |numberOfChannels| channels.
+  AudioFIFO(unsigned numberOfChannels, size_t fifoLength);
+
+  // Push the data from the bus into the FIFO.
+  void push(const AudioBus*);
+
+  // Consume |framesToConsume| frames of data from the FIFO and put them in
+  // |destination|. The corresponding frames are removed from the FIFO.
+  void consume(AudioBus* destination, size_t framesToConsume);
+
+  // Number of frames of data that are currently in the FIFO.
+  size_t framesInFifo() const { return m_framesInFifo; }
+
+ private:
+  // Update the FIFO index by the step, with appropriate wrapping around the
+  // endpoint.
+  int updateIndex(int index, int step) { return (index + step) % m_fifoLength; }
+
+  void findWrapLengths(size_t index,
+                       size_t providerSize,
+                       size_t& part1Length,
+                       size_t& part2Length);
+
+  // The FIFO itself. In reality, the FIFO is a circular buffer.
+  RefPtr<AudioBus> m_fifoAudioBus;
+
+  // The total available space in the FIFO.
+  size_t m_fifoLength;
+
+  // The number of actual elements in the FIFO
+  size_t m_framesInFifo;
+
+  // Where to start reading from the FIFO.
+  size_t m_readIndex;
+
+  // Where to start writing to the FIFO.
+  size_t m_writeIndex;
+};
+
+}  // namespace blink
+
+#endif  // AudioFIFO.h