1 files changed, 85 insertions, 0 deletions
diff --git a/dom/media/webaudio/blink/ReverbInputBuffer.cpp b/dom/media/webaudio/blink/ReverbInputBuffer.cpp
new file mode 100644
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+++ b/dom/media/webaudio/blink/ReverbInputBuffer.cpp
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+/*
+ * Copyright (C) 2010 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.
+ */
+
+#include "ReverbInputBuffer.h"
+#include "mozilla/PodOperations.h"
+
+using namespace mozilla;
+
+namespace WebCore {
+
+ReverbInputBuffer::ReverbInputBuffer(size_t length) : m_writeIndex(0) {
+  m_buffer.SetLength(length);
+  PodZero(m_buffer.Elements(), length);
+}
+
+void ReverbInputBuffer::write(const float* sourceP, size_t numberOfFrames) {
+  // m_writeIndex is atomic and checked by other threads, so only touch
+  // it at the start and end.
+  size_t bufferLength = m_buffer.Length();
+  size_t index = m_writeIndex;
+  size_t newIndex = index + numberOfFrames;
+
+  MOZ_RELEASE_ASSERT(newIndex <= bufferLength);
+
+  memcpy(m_buffer.Elements() + index, sourceP, sizeof(float) * numberOfFrames);
+
+  if (newIndex >= bufferLength) {
+    newIndex = 0;
+  }
+  m_writeIndex = newIndex;
+}
+
+float* ReverbInputBuffer::directReadFrom(int* readIndex,
+                                         size_t numberOfFrames) {
+  size_t bufferLength = m_buffer.Length();
+  bool isPointerGood = readIndex && *readIndex >= 0 &&
+                       *readIndex + numberOfFrames <= bufferLength;
+  MOZ_ASSERT(isPointerGood);
+  if (!isPointerGood) {
+    // Should never happen in practice but return pointer to start of buffer
+    // (avoid crash)
+    if (readIndex) *readIndex = 0;
+    return m_buffer.Elements();
+  }
+
+  float* sourceP = m_buffer.Elements();
+  float* p = sourceP + *readIndex;
+
+  // Update readIndex
+  *readIndex = (*readIndex + numberOfFrames) % bufferLength;
+
+  return p;
+}
+
+void ReverbInputBuffer::reset() {
+  PodZero(m_buffer.Elements(), m_buffer.Length());
+  m_writeIndex = 0;
+}
+
+}  // namespace WebCore