Revert of Introduce PushPullFIFO class and remove other FIFOs

third_party/WebKit/Source/platform/audio/PushPullFIFO.cpp

-// Copyright 2017 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "platform/audio/PushPullFIFO.h"
-
-#include <memory>
-#include "platform/audio/AudioUtilities.h"
-#include "wtf/PtrUtil.h"
-
-namespace blink {
-
-namespace {
-
-// Suppress the warning log if over/underflow happens more than 100 times.
-const unsigned kMaxMessagesToLog = 100;
-}
-
-const size_t PushPullFIFO::kMaxFIFOLength = 65536;
-
-PushPullFIFO::PushPullFIFO(unsigned numberOfChannels, size_t fifoLength)
-    : m_fifoLength(fifoLength),
-      m_framesAvailable(0),
-      m_indexRead(0),
-      m_indexWrite(0),
-      m_overflowCount(0),
-      m_underflowCount(0) {
-  CHECK_LE(m_fifoLength, kMaxFIFOLength);
-  m_fifoBus = AudioBus::create(numberOfChannels, m_fifoLength);
-}
-
-PushPullFIFO::~PushPullFIFO() {}
-
-// Push the data from |inputBus| to FIFO. The size of push is determined by
-// the length of |inputBus|.
-void PushPullFIFO::push(const AudioBus* inputBus) {
-  CHECK(inputBus);
-  CHECK_EQ(inputBus->length(), AudioUtilities::kRenderQuantumFrames);
-  SECURITY_CHECK(inputBus->length() <= m_fifoLength);
-  SECURITY_CHECK(m_indexWrite < m_fifoLength);
-
-  const size_t inputBusLength = inputBus->length();
-  const size_t remainder = m_fifoLength - m_indexWrite;
-
-  for (unsigned i = 0; i < m_fifoBus->numberOfChannels(); ++i) {
-    float* fifoBusChannel = m_fifoBus->channel(i)->mutableData();
-    const float* inputBusChannel = inputBus->channel(i)->data();
-    if (remainder >= inputBusLength) {
-      // The remainder is big enough for the input data.
-      memcpy(fifoBusChannel + m_indexWrite, inputBusChannel,
-             inputBusLength * sizeof(*fifoBusChannel));
-    } else {
-      // The input data overflows the remainder size. Wrap around the index.
-      memcpy(fifoBusChannel + m_indexWrite, inputBusChannel,
-             remainder * sizeof(*fifoBusChannel));
-      memcpy(fifoBusChannel, inputBusChannel + remainder,
-             (inputBusLength - remainder) * sizeof(*fifoBusChannel));
-    }
-  }
-
-  // Update the write index; wrap it around if necessary.
-  m_indexWrite = (m_indexWrite + inputBusLength) % m_fifoLength;
-
-  // In case of overflow, move the |indexRead| to the updated |indexWrite| to
-  // avoid reading overwritten frames by the next pull.
-  if (inputBusLength > m_fifoLength - m_framesAvailable) {
-    m_indexRead = m_indexWrite;
-    if (++m_overflowCount < kMaxMessagesToLog) {
-      LOG(WARNING) << "PushPullFIFO: overflow while pushing ("
-                   << "overflowCount=" << m_overflowCount
-                   << ", availableFrames=" << m_framesAvailable
-                   << ", inputFrames=" << inputBusLength
-                   << ", fifoLength=" << m_fifoLength << ")";
-    }
-  }
-
-  // Update the number of frames available in FIFO.
-  m_framesAvailable =
-      std::min(m_framesAvailable + inputBusLength, m_fifoLength);
-  DCHECK_EQ((m_indexRead + m_framesAvailable) % m_fifoLength, m_indexWrite);
-}
-
-// Pull the data out of FIFO to |outputBus|. If remaining frame in the FIFO
-// is less than the frames to pull, provides remaining frame plus the silence.
-void PushPullFIFO::pull(AudioBus* outputBus, size_t framesRequested) {
-  CHECK(outputBus);
-  SECURITY_CHECK(framesRequested <= outputBus->length());
-  SECURITY_CHECK(framesRequested <= m_fifoLength);
-  SECURITY_CHECK(m_indexRead < m_fifoLength);
-
-  const size_t remainder = m_fifoLength - m_indexRead;
-  const size_t framesToFill = std::min(m_framesAvailable, framesRequested);
-
-  for (unsigned i = 0; i < m_fifoBus->numberOfChannels(); ++i) {
-    const float* fifoBusChannel = m_fifoBus->channel(i)->data();
-    float* outputBusChannel = outputBus->channel(i)->mutableData();
-
-    // Fill up the output bus with the available frames first.
-    if (remainder >= framesToFill) {
-      // The remainder is big enough for the frames to pull.
-      memcpy(outputBusChannel, fifoBusChannel + m_indexRead,
-             framesToFill * sizeof(*fifoBusChannel));
-    } else {
-      // The frames to pull is bigger than the remainder size.
-      // Wrap around the index.
-      memcpy(outputBusChannel, fifoBusChannel + m_indexRead,
-             remainder * sizeof(*fifoBusChannel));
-      memcpy(outputBusChannel + remainder, fifoBusChannel,
-             (framesToFill - remainder) * sizeof(*fifoBusChannel));
-    }
-
-    // The frames available was not enough to fulfill the requested frames. Fill
-    // the rest of the channel with silence.
-    if (framesRequested > framesToFill) {
-      memset(outputBusChannel + framesToFill, 0,
-             (framesRequested - framesToFill) * sizeof(*outputBusChannel));
-    }
-  }
-
-  // Update the read index; wrap it around if necessary.
-  m_indexRead = (m_indexRead + framesToFill) % m_fifoLength;
-
-  // In case of underflow, move the |indexWrite| to the updated |indexRead|.
-  if (framesRequested > framesToFill) {
-    m_indexWrite = m_indexRead;
-    if (m_underflowCount++ < kMaxMessagesToLog) {
-      LOG(WARNING) << "PushPullFIFO: underflow while pulling ("
-                   << "underflowCount=" << m_underflowCount
-                   << ", availableFrames=" << m_framesAvailable
-                   << ", requestedFrames=" << framesRequested
-                   << ", fifoLength=" << m_fifoLength << ")";
-    }
-  }
-
-  // Update the number of frames in FIFO.
-  m_framesAvailable -= framesToFill;
-  DCHECK_EQ((m_indexRead + m_framesAvailable) % m_fifoLength, m_indexWrite);
-}
-
-const PushPullFIFOStateForTest PushPullFIFO::getStateForTest() const {
-  return {length(),     numberOfChannels(), framesAvailable(), m_indexRead,
-          m_indexWrite, m_overflowCount,    m_underflowCount};
-}
-
-}  // namespace blink