1 files changed, 421 insertions, 0 deletions
diff --git a/dom/media/webaudio/AudioBuffer.cpp b/dom/media/webaudio/AudioBuffer.cpp
new file mode 100644
index 000000000..cb834f6a5
--- /dev/null
+++ b/dom/media/webaudio/AudioBuffer.cpp
@@ -0,0 +1,421 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "AudioBuffer.h"
+#include "mozilla/dom/AudioBufferBinding.h"
+#include "jsfriendapi.h"
+#include "mozilla/ErrorResult.h"
+#include "AudioSegment.h"
+#include "AudioChannelFormat.h"
+#include "mozilla/PodOperations.h"
+#include "mozilla/CheckedInt.h"
+#include "mozilla/MemoryReporting.h"
+#include "AudioNodeEngine.h"
+
+namespace mozilla {
+namespace dom {
+
+NS_IMPL_CYCLE_COLLECTION_CLASS(AudioBuffer)
+
+NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(AudioBuffer)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mJSChannels)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK_PRESERVED_WRAPPER
+  tmp->ClearJSChannels();
+NS_IMPL_CYCLE_COLLECTION_UNLINK_END
+
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(AudioBuffer)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE_SCRIPT_OBJECTS
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
+
+NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN(AudioBuffer)
+  NS_IMPL_CYCLE_COLLECTION_TRACE_PRESERVED_WRAPPER
+  for (uint32_t i = 0; i < tmp->mJSChannels.Length(); ++i) {
+    NS_IMPL_CYCLE_COLLECTION_TRACE_JS_MEMBER_CALLBACK(mJSChannels[i])
+  }
+NS_IMPL_CYCLE_COLLECTION_TRACE_END
+
+NS_IMPL_CYCLE_COLLECTION_ROOT_NATIVE(AudioBuffer, AddRef)
+NS_IMPL_CYCLE_COLLECTION_UNROOT_NATIVE(AudioBuffer, Release)
+
+/**
+ * AudioBuffers can be shared between AudioContexts, so we need a separate
+ * mechanism to track their memory usage. This thread-safe class keeps track of
+ * all the AudioBuffers, and gets called back by the memory reporting system
+ * when a memory report is needed, reporting how much memory is used by the
+ * buffers backing AudioBuffer objects. */
+class AudioBufferMemoryTracker : public nsIMemoryReporter
+{
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIMEMORYREPORTER
+
+private:
+  AudioBufferMemoryTracker();
+  virtual ~AudioBufferMemoryTracker();
+
+public:
+  /* Those methods can be called on any thread. */
+  static void RegisterAudioBuffer(const AudioBuffer* aAudioBuffer);
+  static void UnregisterAudioBuffer(const AudioBuffer* aAudioBuffer);
+private:
+  static AudioBufferMemoryTracker* GetInstance();
+  /* Those methods must be called with the lock held. */
+  void RegisterAudioBufferInternal(const AudioBuffer* aAudioBuffer);
+  /* Returns the number of buffers still present in the hash table. */
+  uint32_t UnregisterAudioBufferInternal(const AudioBuffer* aAudioBuffer);
+  void Init();
+
+  /* This protects all members of this class. */
+  static StaticMutex sMutex;
+  static StaticRefPtr<AudioBufferMemoryTracker> sSingleton;
+  nsTHashtable<nsPtrHashKey<const AudioBuffer>> mBuffers;
+};
+
+StaticRefPtr<AudioBufferMemoryTracker> AudioBufferMemoryTracker::sSingleton;
+StaticMutex AudioBufferMemoryTracker::sMutex;
+
+NS_IMPL_ISUPPORTS(AudioBufferMemoryTracker, nsIMemoryReporter);
+
+AudioBufferMemoryTracker* AudioBufferMemoryTracker::GetInstance()
+{
+  sMutex.AssertCurrentThreadOwns();
+  if (!sSingleton) {
+    sSingleton = new AudioBufferMemoryTracker();
+    sSingleton->Init();
+  }
+  return sSingleton;
+}
+
+AudioBufferMemoryTracker::AudioBufferMemoryTracker()
+{
+}
+
+void
+AudioBufferMemoryTracker::Init()
+{
+  RegisterWeakMemoryReporter(this);
+}
+
+AudioBufferMemoryTracker::~AudioBufferMemoryTracker()
+{
+  UnregisterWeakMemoryReporter(this);
+}
+
+void
+AudioBufferMemoryTracker::RegisterAudioBuffer(const AudioBuffer* aAudioBuffer)
+{
+  StaticMutexAutoLock lock(sMutex);
+  AudioBufferMemoryTracker* tracker = AudioBufferMemoryTracker::GetInstance();
+  tracker->RegisterAudioBufferInternal(aAudioBuffer);
+}
+
+void
+AudioBufferMemoryTracker::UnregisterAudioBuffer(const AudioBuffer* aAudioBuffer)
+{
+  StaticMutexAutoLock lock(sMutex);
+  AudioBufferMemoryTracker* tracker = AudioBufferMemoryTracker::GetInstance();
+  uint32_t count;
+  count = tracker->UnregisterAudioBufferInternal(aAudioBuffer);
+  if (count == 0) {
+    sSingleton = nullptr;
+  }
+}
+
+void
+AudioBufferMemoryTracker::RegisterAudioBufferInternal(const AudioBuffer* aAudioBuffer)
+{
+  sMutex.AssertCurrentThreadOwns();
+  mBuffers.PutEntry(aAudioBuffer);
+}
+
+uint32_t
+AudioBufferMemoryTracker::UnregisterAudioBufferInternal(const AudioBuffer* aAudioBuffer)
+{
+  sMutex.AssertCurrentThreadOwns();
+  mBuffers.RemoveEntry(aAudioBuffer);
+  return mBuffers.Count();
+}
+
+MOZ_DEFINE_MALLOC_SIZE_OF(AudioBufferMemoryTrackerMallocSizeOf)
+
+NS_IMETHODIMP
+AudioBufferMemoryTracker::CollectReports(nsIHandleReportCallback* aHandleReport,
+                                         nsISupports* aData, bool)
+{
+  size_t amount = 0;
+
+  for (auto iter = mBuffers.Iter(); !iter.Done(); iter.Next()) {
+    amount += iter.Get()->GetKey()->SizeOfIncludingThis(AudioBufferMemoryTrackerMallocSizeOf);
+  }
+
+  MOZ_COLLECT_REPORT(
+    "explicit/webaudio/audiobuffer", KIND_HEAP, UNITS_BYTES, amount,
+    "Memory used by AudioBuffer objects (Web Audio).");
+
+  return NS_OK;
+}
+
+AudioBuffer::AudioBuffer(AudioContext* aContext, uint32_t aNumberOfChannels,
+                         uint32_t aLength, float aSampleRate,
+                         already_AddRefed<ThreadSharedFloatArrayBufferList>
+                           aInitialContents)
+  : mOwnerWindow(do_GetWeakReference(aContext->GetOwner())),
+    mSharedChannels(aInitialContents),
+    mLength(aLength),
+    mSampleRate(aSampleRate)
+{
+  MOZ_ASSERT(!mSharedChannels ||
+             mSharedChannels->GetChannels() == aNumberOfChannels);
+  mJSChannels.SetLength(aNumberOfChannels);
+  mozilla::HoldJSObjects(this);
+  AudioBufferMemoryTracker::RegisterAudioBuffer(this);
+}
+
+AudioBuffer::~AudioBuffer()
+{
+  AudioBufferMemoryTracker::UnregisterAudioBuffer(this);
+  ClearJSChannels();
+  mozilla::DropJSObjects(this);
+}
+
+void
+AudioBuffer::ClearJSChannels()
+{
+  mJSChannels.Clear();
+}
+
+/* static */ already_AddRefed<AudioBuffer>
+AudioBuffer::Create(AudioContext* aContext, uint32_t aNumberOfChannels,
+                    uint32_t aLength, float aSampleRate,
+                    already_AddRefed<ThreadSharedFloatArrayBufferList>
+                      aInitialContents,
+                    ErrorResult& aRv)
+{
+  // Note that a buffer with zero channels is permitted here for the sake of
+  // AudioProcessingEvent, where channel counts must match parameters passed
+  // to createScriptProcessor(), one of which may be zero.
+  if (aSampleRate < WebAudioUtils::MinSampleRate ||
+      aSampleRate > WebAudioUtils::MaxSampleRate ||
+      aNumberOfChannels > WebAudioUtils::MaxChannelCount ||
+      !aLength || aLength > INT32_MAX) {
+    aRv.Throw(NS_ERROR_DOM_INDEX_SIZE_ERR);
+    return nullptr;
+  }
+
+  RefPtr<AudioBuffer> buffer =
+    new AudioBuffer(aContext, aNumberOfChannels, aLength, aSampleRate,
+                    Move(aInitialContents));
+
+  return buffer.forget();
+}
+
+JSObject*
+AudioBuffer::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
+{
+  return AudioBufferBinding::Wrap(aCx, this, aGivenProto);
+}
+
+bool
+AudioBuffer::RestoreJSChannelData(JSContext* aJSContext)
+{
+  for (uint32_t i = 0; i < mJSChannels.Length(); ++i) {
+    if (mJSChannels[i]) {
+      // Already have data in JS array.
+      continue;
+    }
+
+    // The following code first zeroes the array and then copies our data
+    // into it. We could avoid this with additional JS APIs to construct
+    // an array (or ArrayBuffer) containing initial data.
+    JS::Rooted<JSObject*> array(aJSContext,
+                                JS_NewFloat32Array(aJSContext, mLength));
+    if (!array) {
+      return false;
+    }
+    if (mSharedChannels) {
+      // "4. Attach ArrayBuffers containing copies of the data to the
+      // AudioBuffer, to be returned by the next call to getChannelData."
+      const float* data = mSharedChannels->GetData(i);
+      JS::AutoCheckCannotGC nogc;
+      bool isShared;
+      mozilla::PodCopy(JS_GetFloat32ArrayData(array, &isShared, nogc), data, mLength);
+      MOZ_ASSERT(!isShared); // Was created as unshared above
+    }
+    mJSChannels[i] = array;
+  }
+
+  mSharedChannels = nullptr;
+
+  return true;
+}
+
+void
+AudioBuffer::CopyFromChannel(const Float32Array& aDestination, uint32_t aChannelNumber,
+                             uint32_t aStartInChannel, ErrorResult& aRv)
+{
+  aDestination.ComputeLengthAndData();
+
+  uint32_t length = aDestination.Length();
+  CheckedInt<uint32_t> end = aStartInChannel;
+  end += length;
+  if (aChannelNumber >= NumberOfChannels() ||
+      !end.isValid() || end.value() > mLength) {
+    aRv.Throw(NS_ERROR_DOM_INDEX_SIZE_ERR);
+    return;
+  }
+
+  JS::AutoCheckCannotGC nogc;
+  JSObject* channelArray = mJSChannels[aChannelNumber];
+  const float* sourceData = nullptr;
+  if (channelArray) {
+    if (JS_GetTypedArrayLength(channelArray) != mLength) {
+      // The array's buffer was detached.
+      aRv.Throw(NS_ERROR_DOM_INDEX_SIZE_ERR);
+      return;
+    }
+
+    bool isShared = false;
+    sourceData = JS_GetFloat32ArrayData(channelArray, &isShared, nogc);
+    // The sourceData arrays should all have originated in
+    // RestoreJSChannelData, where they are created unshared.
+    MOZ_ASSERT(!isShared);
+  } else if (mSharedChannels) {
+    sourceData = mSharedChannels->GetData(aChannelNumber);
+  }
+
+  if (sourceData) {
+    PodMove(aDestination.Data(), sourceData + aStartInChannel, length);
+  } else {
+    PodZero(aDestination.Data(), length);
+  }
+}
+
+void
+AudioBuffer::CopyToChannel(JSContext* aJSContext, const Float32Array& aSource,
+                           uint32_t aChannelNumber, uint32_t aStartInChannel,
+                           ErrorResult& aRv)
+{
+  aSource.ComputeLengthAndData();
+
+  uint32_t length = aSource.Length();
+  CheckedInt<uint32_t> end = aStartInChannel;
+  end += length;
+  if (aChannelNumber >= NumberOfChannels() ||
+      !end.isValid() || end.value() > mLength) {
+    aRv.Throw(NS_ERROR_DOM_INDEX_SIZE_ERR);
+    return;
+  }
+
+  if (!RestoreJSChannelData(aJSContext)) {
+    aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
+    return;
+  }
+
+  JS::AutoCheckCannotGC nogc;
+  JSObject* channelArray = mJSChannels[aChannelNumber];
+  if (JS_GetTypedArrayLength(channelArray) != mLength) {
+    // The array's buffer was detached.
+    aRv.Throw(NS_ERROR_DOM_INDEX_SIZE_ERR);
+    return;
+  }
+
+  bool isShared = false;
+  float* channelData = JS_GetFloat32ArrayData(channelArray, &isShared, nogc);
+  // The channelData arrays should all have originated in
+  // RestoreJSChannelData, where they are created unshared.
+  MOZ_ASSERT(!isShared);
+  PodMove(channelData + aStartInChannel, aSource.Data(), length);
+}
+
+void
+AudioBuffer::GetChannelData(JSContext* aJSContext, uint32_t aChannel,
+                            JS::MutableHandle<JSObject*> aRetval,
+                            ErrorResult& aRv)
+{
+  if (aChannel >= NumberOfChannels()) {
+    aRv.Throw(NS_ERROR_DOM_SYNTAX_ERR);
+    return;
+  }
+
+  if (!RestoreJSChannelData(aJSContext)) {
+    aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
+    return;
+  }
+
+  aRetval.set(mJSChannels[aChannel]);
+}
+
+already_AddRefed<ThreadSharedFloatArrayBufferList>
+AudioBuffer::StealJSArrayDataIntoSharedChannels(JSContext* aJSContext)
+{
+  // "1. If any of the AudioBuffer's ArrayBuffer have been detached, abort
+  // these steps, and return a zero-length channel data buffers to the
+  // invoker."
+  for (uint32_t i = 0; i < mJSChannels.Length(); ++i) {
+    JSObject* channelArray = mJSChannels[i];
+    if (!channelArray || mLength != JS_GetTypedArrayLength(channelArray)) {
+      // Either empty buffer or one of the arrays' buffers was detached.
+      return nullptr;
+    }
+  }
+
+  // "2. Detach all ArrayBuffers for arrays previously returned by
+  // getChannelData on this AudioBuffer."
+  // "3. Retain the underlying data buffers from those ArrayBuffers and return
+  // references to them to the invoker."
+  RefPtr<ThreadSharedFloatArrayBufferList> result =
+    new ThreadSharedFloatArrayBufferList(mJSChannels.Length());
+  for (uint32_t i = 0; i < mJSChannels.Length(); ++i) {
+    JS::Rooted<JSObject*> arrayBufferView(aJSContext, mJSChannels[i]);
+    bool isSharedMemory;
+    JS::Rooted<JSObject*> arrayBuffer(aJSContext,
+                                      JS_GetArrayBufferViewBuffer(aJSContext,
+                                                                  arrayBufferView,
+                                                                  &isSharedMemory));
+    // The channel data arrays should all have originated in
+    // RestoreJSChannelData, where they are created unshared.
+    MOZ_ASSERT(!isSharedMemory);
+    auto stolenData = arrayBuffer
+      ? static_cast<float*>(JS_StealArrayBufferContents(aJSContext,
+                                                        arrayBuffer))
+      : nullptr;
+    if (stolenData) {
+      result->SetData(i, stolenData, js_free, stolenData);
+    } else {
+      NS_ASSERTION(i == 0, "some channels lost when contents not acquired");
+      return nullptr;
+    }
+  }
+
+  for (uint32_t i = 0; i < mJSChannels.Length(); ++i) {
+    mJSChannels[i] = nullptr;
+  }
+
+  return result.forget();
+}
+
+ThreadSharedFloatArrayBufferList*
+AudioBuffer::GetThreadSharedChannelsForRate(JSContext* aJSContext)
+{
+  if (!mSharedChannels) {
+    mSharedChannels = StealJSArrayDataIntoSharedChannels(aJSContext);
+  }
+
+  return mSharedChannels;
+}
+
+size_t
+AudioBuffer::SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const
+{
+  size_t amount = aMallocSizeOf(this);
+  amount += mJSChannels.ShallowSizeOfExcludingThis(aMallocSizeOf);
+  if (mSharedChannels) {
+    amount += mSharedChannels->SizeOfIncludingThis(aMallocSizeOf);
+  }
+  return amount;
+}
+
+} // namespace dom
+} // namespace mozilla