dom/media/mediasource/SourceBuffer.cpp
author Sylvestre Ledru <sledru@mozilla.com>
Mon, 19 Nov 2018 13:25:37 +0000
changeset 446960 0ceae9db9ec0be18daa1a279511ad305723185d4
parent 423859 a97feb8161b7a4c60a539d83cb702a6e50fab1b1
child 454520 5f4630838d46dd81dadb13220a4af0da9e23a619
permissions -rw-r--r--
Bug 1204606 - Reformat of dom/media r=jya # skip-blame Differential Revision: https://phabricator.services.mozilla.com/D12251

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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 "SourceBuffer.h"

#include "AsyncEventRunner.h"
#include "MediaData.h"
#include "MediaSourceDemuxer.h"
#include "MediaSourceUtils.h"
#include "mozilla/ErrorResult.h"
#include "mozilla/FloatingPoint.h"
#include "mozilla/Preferences.h"
#include "mozilla/dom/MediaSourceBinding.h"
#include "mozilla/dom/TimeRanges.h"
#include "nsError.h"
#include "nsIEventTarget.h"
#include "nsIRunnable.h"
#include "nsThreadUtils.h"
#include "mozilla/Logging.h"
#include <time.h>
#include "TimeUnits.h"

// GetCurrentTime is defined in winbase.h as zero argument macro forwarding to
// GetTickCount() and conflicts with MediaDecoder::GetCurrentTime
// implementation.
#ifdef GetCurrentTime
#undef GetCurrentTime
#endif

struct JSContext;
class JSObject;

extern mozilla::LogModule* GetMediaSourceLog();
extern mozilla::LogModule* GetMediaSourceAPILog();

#define MSE_DEBUG(arg, ...)                                                  \
  DDMOZ_LOG(GetMediaSourceLog(), mozilla::LogLevel::Debug, "(%s)::%s: " arg, \
            mType.OriginalString().Data(), __func__, ##__VA_ARGS__)
#define MSE_DEBUGV(arg, ...)                                                   \
  DDMOZ_LOG(GetMediaSourceLog(), mozilla::LogLevel::Verbose, "(%s)::%s: " arg, \
            mType.OriginalString().Data(), __func__, ##__VA_ARGS__)
#define MSE_API(arg, ...)                                              \
  DDMOZ_LOG(GetMediaSourceAPILog(), mozilla::LogLevel::Debug,          \
            "(%s)::%s: " arg, mType.OriginalString().Data(), __func__, \
            ##__VA_ARGS__)

namespace mozilla {

using media::TimeUnit;
typedef SourceBufferAttributes::AppendState AppendState;

namespace dom {

void SourceBuffer::SetMode(SourceBufferAppendMode aMode, ErrorResult& aRv) {
  MOZ_ASSERT(NS_IsMainThread());
  MSE_API("SetMode(aMode=%" PRIu32 ")", static_cast<uint32_t>(aMode));
  if (!IsAttached() || mUpdating) {
    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
    return;
  }
  if (mCurrentAttributes.mGenerateTimestamps &&
      aMode == SourceBufferAppendMode::Segments) {
    aRv.Throw(NS_ERROR_DOM_TYPE_ERR);
    return;
  }
  MOZ_ASSERT(mMediaSource->ReadyState() != MediaSourceReadyState::Closed);
  if (mMediaSource->ReadyState() == MediaSourceReadyState::Ended) {
    mMediaSource->SetReadyState(MediaSourceReadyState::Open);
  }
  if (mCurrentAttributes.GetAppendState() ==
      AppendState::PARSING_MEDIA_SEGMENT) {
    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
    return;
  }

  if (aMode == SourceBufferAppendMode::Sequence) {
    // Will set GroupStartTimestamp to GroupEndTimestamp.
    mCurrentAttributes.RestartGroupStartTimestamp();
  }

  mCurrentAttributes.SetAppendMode(aMode);
}

void SourceBuffer::SetTimestampOffset(double aTimestampOffset,
                                      ErrorResult& aRv) {
  MOZ_ASSERT(NS_IsMainThread());
  MSE_API("SetTimestampOffset(aTimestampOffset=%f)", aTimestampOffset);
  if (!IsAttached() || mUpdating) {
    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
    return;
  }
  MOZ_ASSERT(mMediaSource->ReadyState() != MediaSourceReadyState::Closed);
  if (mMediaSource->ReadyState() == MediaSourceReadyState::Ended) {
    mMediaSource->SetReadyState(MediaSourceReadyState::Open);
  }
  if (mCurrentAttributes.GetAppendState() ==
      AppendState::PARSING_MEDIA_SEGMENT) {
    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
    return;
  }
  mCurrentAttributes.SetApparentTimestampOffset(aTimestampOffset);
  if (mCurrentAttributes.GetAppendMode() == SourceBufferAppendMode::Sequence) {
    mCurrentAttributes.SetGroupStartTimestamp(
        mCurrentAttributes.GetTimestampOffset());
  }
}

TimeRanges* SourceBuffer::GetBuffered(ErrorResult& aRv) {
  MOZ_ASSERT(NS_IsMainThread());
  // http://w3c.github.io/media-source/index.html#widl-SourceBuffer-buffered
  // 1. If this object has been removed from the sourceBuffers attribute of the
  // parent media source then throw an InvalidStateError exception and abort
  // these steps.
  if (!IsAttached()) {
    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
    return nullptr;
  }
  bool rangeChanged = true;
  media::TimeIntervals intersection = mTrackBuffersManager->Buffered();
  MSE_DEBUGV("intersection=%s", DumpTimeRanges(intersection).get());
  if (mBuffered) {
    media::TimeIntervals currentValue(mBuffered->ToTimeIntervals());
    rangeChanged = (intersection != currentValue);
    MSE_DEBUGV("currentValue=%s", DumpTimeRanges(currentValue).get());
  }
  // 5. If intersection ranges does not contain the exact same range information
  // as the current value of this attribute, then update the current value of
  // this attribute to intersection ranges.
  if (rangeChanged) {
    mBuffered = new TimeRanges(ToSupports(this), intersection);
  }
  // 6. Return the current value of this attribute.
  return mBuffered;
}

media::TimeIntervals SourceBuffer::GetTimeIntervals() {
  return mTrackBuffersManager->Buffered();
}

void SourceBuffer::SetAppendWindowStart(double aAppendWindowStart,
                                        ErrorResult& aRv) {
  MOZ_ASSERT(NS_IsMainThread());
  MSE_API("SetAppendWindowStart(aAppendWindowStart=%f)", aAppendWindowStart);
  DDLOG(DDLogCategory::API, "SetAppendWindowStart", aAppendWindowStart);
  if (!IsAttached() || mUpdating) {
    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
    return;
  }
  if (aAppendWindowStart < 0 ||
      aAppendWindowStart >= mCurrentAttributes.GetAppendWindowEnd()) {
    aRv.Throw(NS_ERROR_DOM_TYPE_ERR);
    return;
  }
  mCurrentAttributes.SetAppendWindowStart(aAppendWindowStart);
}

void SourceBuffer::SetAppendWindowEnd(double aAppendWindowEnd,
                                      ErrorResult& aRv) {
  MOZ_ASSERT(NS_IsMainThread());
  MSE_API("SetAppendWindowEnd(aAppendWindowEnd=%f)", aAppendWindowEnd);
  DDLOG(DDLogCategory::API, "SetAppendWindowEnd", aAppendWindowEnd);
  if (!IsAttached() || mUpdating) {
    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
    return;
  }
  if (IsNaN(aAppendWindowEnd) ||
      aAppendWindowEnd <= mCurrentAttributes.GetAppendWindowStart()) {
    aRv.Throw(NS_ERROR_DOM_TYPE_ERR);
    return;
  }
  mCurrentAttributes.SetAppendWindowEnd(aAppendWindowEnd);
}

void SourceBuffer::AppendBuffer(const ArrayBuffer& aData, ErrorResult& aRv) {
  MOZ_ASSERT(NS_IsMainThread());
  MSE_API("AppendBuffer(ArrayBuffer)");
  aData.ComputeLengthAndData();
  DDLOG(DDLogCategory::API, "AppendBuffer", aData.Length());
  AppendData(aData.Data(), aData.Length(), aRv);
}

void SourceBuffer::AppendBuffer(const ArrayBufferView& aData,
                                ErrorResult& aRv) {
  MOZ_ASSERT(NS_IsMainThread());
  MSE_API("AppendBuffer(ArrayBufferView)");
  aData.ComputeLengthAndData();
  DDLOG(DDLogCategory::API, "AppendBuffer", aData.Length());
  AppendData(aData.Data(), aData.Length(), aRv);
}

already_AddRefed<Promise> SourceBuffer::AppendBufferAsync(
    const ArrayBuffer& aData, ErrorResult& aRv) {
  MOZ_ASSERT(NS_IsMainThread());

  MSE_API("AppendBufferAsync(ArrayBuffer)");
  aData.ComputeLengthAndData();
  DDLOG(DDLogCategory::API, "AppendBufferAsync", aData.Length());

  return AppendDataAsync(aData.Data(), aData.Length(), aRv);
}

already_AddRefed<Promise> SourceBuffer::AppendBufferAsync(
    const ArrayBufferView& aData, ErrorResult& aRv) {
  MOZ_ASSERT(NS_IsMainThread());

  MSE_API("AppendBufferAsync(ArrayBufferView)");
  aData.ComputeLengthAndData();
  DDLOG(DDLogCategory::API, "AppendBufferAsync", aData.Length());

  return AppendDataAsync(aData.Data(), aData.Length(), aRv);
}

void SourceBuffer::Abort(ErrorResult& aRv) {
  MOZ_ASSERT(NS_IsMainThread());
  MSE_API("Abort()");
  if (!IsAttached()) {
    DDLOG(DDLogCategory::API, "Abort", NS_ERROR_DOM_INVALID_STATE_ERR);
    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
    return;
  }
  if (mMediaSource->ReadyState() != MediaSourceReadyState::Open) {
    DDLOG(DDLogCategory::API, "Abort", NS_ERROR_DOM_INVALID_STATE_ERR);
    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
    return;
  }
  if (mPendingRemoval.Exists()) {
    DDLOG(DDLogCategory::API, "Abort", NS_ERROR_DOM_INVALID_STATE_ERR);
    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
    return;
  }
  DDLOG(DDLogCategory::API, "Abort", NS_OK);
  AbortBufferAppend();
  ResetParserState();
  mCurrentAttributes.SetAppendWindowStart(0);
  mCurrentAttributes.SetAppendWindowEnd(PositiveInfinity<double>());
}

void SourceBuffer::AbortBufferAppend() {
  if (mUpdating) {
    mCompletionPromise.DisconnectIfExists();
    if (mPendingAppend.Exists()) {
      mPendingAppend.Disconnect();
      mTrackBuffersManager->AbortAppendData();
    }
    AbortUpdating();
  }
}

void SourceBuffer::ResetParserState() {
  mTrackBuffersManager->ResetParserState(mCurrentAttributes);
}

void SourceBuffer::Remove(double aStart, double aEnd, ErrorResult& aRv) {
  MOZ_ASSERT(NS_IsMainThread());
  MSE_API("Remove(aStart=%f, aEnd=%f)", aStart, aEnd);
  DDLOG(DDLogCategory::API, "Remove-from", aStart);
  DDLOG(DDLogCategory::API, "Remove-until", aEnd);

  PrepareRemove(aStart, aEnd, aRv);
  if (aRv.Failed()) {
    return;
  }
  RangeRemoval(aStart, aEnd);
}

already_AddRefed<Promise> SourceBuffer::RemoveAsync(double aStart, double aEnd,
                                                    ErrorResult& aRv) {
  MOZ_ASSERT(NS_IsMainThread());
  MSE_API("RemoveAsync(aStart=%f, aEnd=%f)", aStart, aEnd);
  DDLOG(DDLogCategory::API, "Remove-from", aStart);
  DDLOG(DDLogCategory::API, "Remove-until", aEnd);

  if (!IsAttached()) {
    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
    return nullptr;
  }

  nsCOMPtr<nsIGlobalObject> parentObject =
      do_QueryInterface(mMediaSource->GetParentObject());
  if (!parentObject) {
    aRv.Throw(NS_ERROR_UNEXPECTED);
    return nullptr;
  }

  RefPtr<Promise> promise = Promise::Create(parentObject, aRv);
  if (aRv.Failed()) {
    return nullptr;
  }

  PrepareRemove(aStart, aEnd, aRv);

  if (aRv.Failed()) {
    // The bindings will automatically return a rejected promise.
    return nullptr;
  }
  MOZ_ASSERT(!mDOMPromise, "Can't have a pending operation going");
  mDOMPromise = promise;
  RangeRemoval(aStart, aEnd);

  return promise.forget();
}

void SourceBuffer::PrepareRemove(double aStart, double aEnd, ErrorResult& aRv) {
  if (!IsAttached()) {
    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
    return;
  }
  if (mUpdating) {
    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
    return;
  }
  if (IsNaN(mMediaSource->Duration()) || aStart < 0 ||
      aStart > mMediaSource->Duration() || aEnd <= aStart || IsNaN(aEnd)) {
    aRv.Throw(NS_ERROR_DOM_TYPE_ERR);
    return;
  }
  if (mMediaSource->ReadyState() == MediaSourceReadyState::Ended) {
    mMediaSource->SetReadyState(MediaSourceReadyState::Open);
  }
}

void SourceBuffer::RangeRemoval(double aStart, double aEnd) {
  StartUpdating();

  RefPtr<SourceBuffer> self = this;
  mTrackBuffersManager
      ->RangeRemoval(TimeUnit::FromSeconds(aStart), TimeUnit::FromSeconds(aEnd))
      ->Then(mAbstractMainThread, __func__,
             [self](bool) {
               self->mPendingRemoval.Complete();
               self->StopUpdating();
             },
             []() { MOZ_ASSERT(false); })
      ->Track(mPendingRemoval);
}

void SourceBuffer::ChangeType(const nsAString& aType, ErrorResult& aRv) {
  MOZ_ASSERT(NS_IsMainThread());

  // 1. If type is an empty string then throw a TypeError exception and abort
  //    these steps.
  if (aType.IsEmpty()) {
    aRv.Throw(NS_ERROR_DOM_TYPE_ERR);
    return;
  }

  // 2. If this object has been removed from the sourceBuffers attribute of the
  //    parent media source , then throw an InvalidStateError exception and
  //    abort these steps.
  // 3. If the updating attribute equals true, then throw an InvalidStateError
  //    exception and abort these steps.
  if (!IsAttached() || mUpdating) {
    DDLOG(DDLogCategory::API, "ChangeType", NS_ERROR_DOM_INVALID_STATE_ERR);
    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
    return;
  }

  // 4. If type contains a MIME type that is not supported or contains a MIME
  //    type that is not supported with the types specified (currently or
  //    previously) of SourceBuffer objects in the sourceBuffers attribute of
  //    the parent media source , then throw a NotSupportedError exception and
  //    abort these steps.
  DecoderDoctorDiagnostics diagnostics;
  nsresult rv = MediaSource::IsTypeSupported(aType, &diagnostics);
  diagnostics.StoreFormatDiagnostics(
      mMediaSource->GetOwner() ? mMediaSource->GetOwner()->GetExtantDoc()
                               : nullptr,
      aType, NS_SUCCEEDED(rv), __func__);
  MSE_API("ChangeType(aType=%s)%s", NS_ConvertUTF16toUTF8(aType).get(),
          rv == NS_OK ? "" : " [not supported]");
  if (NS_FAILED(rv)) {
    DDLOG(DDLogCategory::API, "ChangeType", rv);
    aRv.Throw(rv);
    return;
  }

  // 5. If the readyState attribute of the parent media source is in the "ended"
  //    state then run the following steps:
  //    1. Set the readyState attribute of the parent media source to "open"
  //    2.   Queue a task to fire a simple event named sourceopen at the parent
  //         media source .
  MOZ_ASSERT(mMediaSource->ReadyState() != MediaSourceReadyState::Closed);
  if (mMediaSource->ReadyState() == MediaSourceReadyState::Ended) {
    mMediaSource->SetReadyState(MediaSourceReadyState::Open);
  }
  Maybe<MediaContainerType> containerType = MakeMediaContainerType(aType);
  MOZ_ASSERT(containerType);
  mType = *containerType;
  // 6. Run the reset parser state algorithm .
  ResetParserState();

  // 7. Update the generate timestamps flag on this SourceBuffer object to the
  //    value in the "Generate Timestamps Flag" column of the byte stream format
  //    registry [ MSE-REGISTRY ] entry that is associated with type .
  if (mType.Type() == MEDIAMIMETYPE("audio/mpeg") ||
      mType.Type() == MEDIAMIMETYPE("audio/aac")) {
    mCurrentAttributes.mGenerateTimestamps = true;
    // 8. If the generate timestamps flag equals true:
    //    Set the mode attribute on this SourceBuffer object to "sequence" ,
    //    including running the associated steps for that attribute being set.
    ErrorResult dummy;
    SetMode(SourceBufferAppendMode::Sequence, dummy);
  } else {
    mCurrentAttributes.mGenerateTimestamps = false;
    //    Otherwise: Keep the previous value of the mode attribute on this
    //    SourceBuffer object, without running any associated steps for that
    //    attribute being set.
  }

  // 9. Set pending initialization segment for changeType flag to true.
  mTrackBuffersManager->ChangeType(mType);
}

void SourceBuffer::Detach() {
  MOZ_ASSERT(NS_IsMainThread());
  MSE_DEBUG("Detach");
  if (!mMediaSource) {
    MSE_DEBUG("Already detached");
    return;
  }
  AbortBufferAppend();
  if (mTrackBuffersManager) {
    mMediaSource->GetDecoder()->GetDemuxer()->DetachSourceBuffer(
        mTrackBuffersManager);
    mTrackBuffersManager->Detach();
  }
  mTrackBuffersManager = nullptr;
  mMediaSource = nullptr;
}

void SourceBuffer::Ended() {
  MOZ_ASSERT(NS_IsMainThread());
  MOZ_ASSERT(IsAttached());
  MSE_DEBUG("Ended");
  mTrackBuffersManager->Ended();
}

SourceBuffer::SourceBuffer(MediaSource* aMediaSource,
                           const MediaContainerType& aType)
    : DOMEventTargetHelper(aMediaSource->GetParentObject()),
      mMediaSource(aMediaSource),
      mAbstractMainThread(aMediaSource->AbstractMainThread()),
      mCurrentAttributes(aType.Type() == MEDIAMIMETYPE("audio/mpeg") ||
                         aType.Type() == MEDIAMIMETYPE("audio/aac")),
      mUpdating(false),
      mActive(false),
      mType(aType) {
  MOZ_ASSERT(NS_IsMainThread());
  MOZ_ASSERT(aMediaSource);

  mTrackBuffersManager =
      new TrackBuffersManager(aMediaSource->GetDecoder(), aType);
  DDLINKCHILD("track buffers manager", mTrackBuffersManager.get());

  MSE_DEBUG("Create mTrackBuffersManager=%p", mTrackBuffersManager.get());

  ErrorResult dummy;
  if (mCurrentAttributes.mGenerateTimestamps) {
    SetMode(SourceBufferAppendMode::Sequence, dummy);
  } else {
    SetMode(SourceBufferAppendMode::Segments, dummy);
  }
  mMediaSource->GetDecoder()->GetDemuxer()->AttachSourceBuffer(
      mTrackBuffersManager);
}

SourceBuffer::~SourceBuffer() {
  MOZ_ASSERT(NS_IsMainThread());
  MOZ_ASSERT(!mMediaSource);
  MSE_DEBUG("");
}

MediaSource* SourceBuffer::GetParentObject() const { return mMediaSource; }

JSObject* SourceBuffer::WrapObject(JSContext* aCx,
                                   JS::Handle<JSObject*> aGivenProto) {
  return SourceBuffer_Binding::Wrap(aCx, this, aGivenProto);
}

void SourceBuffer::DispatchSimpleEvent(const char* aName) {
  MOZ_ASSERT(NS_IsMainThread());
  MSE_API("Dispatch event '%s'", aName);
  DispatchTrustedEvent(NS_ConvertUTF8toUTF16(aName));
}

void SourceBuffer::QueueAsyncSimpleEvent(const char* aName) {
  MSE_DEBUG("Queuing event '%s'", aName);
  nsCOMPtr<nsIRunnable> event = new AsyncEventRunner<SourceBuffer>(this, aName);
  mAbstractMainThread->Dispatch(event.forget());
}

void SourceBuffer::StartUpdating() {
  MOZ_ASSERT(NS_IsMainThread());
  MOZ_ASSERT(!mUpdating);
  mUpdating = true;
  QueueAsyncSimpleEvent("updatestart");
}

void SourceBuffer::StopUpdating() {
  MOZ_ASSERT(NS_IsMainThread());
  if (!mUpdating) {
    // The buffer append or range removal algorithm  has been interrupted by
    // abort().
    return;
  }
  mUpdating = false;
  QueueAsyncSimpleEvent("update");
  QueueAsyncSimpleEvent("updateend");
  if (mDOMPromise) {
    mDOMPromise->MaybeResolveWithUndefined();
    mDOMPromise = nullptr;
  }
}

void SourceBuffer::AbortUpdating() {
  MOZ_ASSERT(NS_IsMainThread());
  mUpdating = false;
  QueueAsyncSimpleEvent("abort");
  QueueAsyncSimpleEvent("updateend");
  if (mDOMPromise) {
    mDOMPromise->MaybeReject(NS_ERROR_DOM_MEDIA_ABORT_ERR);
    mDOMPromise = nullptr;
  }
}

void SourceBuffer::CheckEndTime() {
  MOZ_ASSERT(NS_IsMainThread());
  // Check if we need to update mMediaSource duration
  double endTime = mCurrentAttributes.GetGroupEndTimestamp().ToSeconds();
  double duration = mMediaSource->Duration();
  if (endTime > duration) {
    mMediaSource->SetDuration(endTime);
  }
}

void SourceBuffer::AppendData(const uint8_t* aData, uint32_t aLength,
                              ErrorResult& aRv) {
  MOZ_ASSERT(NS_IsMainThread());
  MSE_DEBUG("AppendData(aLength=%u)", aLength);

  RefPtr<MediaByteBuffer> data = PrepareAppend(aData, aLength, aRv);
  if (!data) {
    return;
  }
  StartUpdating();

  mTrackBuffersManager->AppendData(data.forget(), mCurrentAttributes)
      ->Then(mAbstractMainThread, __func__, this,
             &SourceBuffer::AppendDataCompletedWithSuccess,
             &SourceBuffer::AppendDataErrored)
      ->Track(mPendingAppend);
}

already_AddRefed<Promise> SourceBuffer::AppendDataAsync(const uint8_t* aData,
                                                        uint32_t aLength,
                                                        ErrorResult& aRv) {
  MOZ_ASSERT(NS_IsMainThread());

  if (!IsAttached()) {
    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
    return nullptr;
  }

  nsCOMPtr<nsIGlobalObject> parentObject =
      do_QueryInterface(mMediaSource->GetParentObject());
  if (!parentObject) {
    aRv.Throw(NS_ERROR_UNEXPECTED);
    return nullptr;
  }

  RefPtr<Promise> promise = Promise::Create(parentObject, aRv);
  if (aRv.Failed()) {
    return nullptr;
  }

  AppendData(aData, aLength, aRv);

  if (aRv.Failed()) {
    return nullptr;
  }

  MOZ_ASSERT(!mDOMPromise, "Can't have a pending operation going");
  mDOMPromise = promise;

  return promise.forget();
}

void SourceBuffer::AppendDataCompletedWithSuccess(
    const SourceBufferTask::AppendBufferResult& aResult) {
  MOZ_ASSERT(mUpdating);
  mPendingAppend.Complete();
  DDLOG(DDLogCategory::API, "AppendBuffer-completed", NS_OK);

  if (aResult.first()) {
    if (!mActive) {
      mActive = true;
      MSE_DEBUG("Init segment received");
      RefPtr<SourceBuffer> self = this;
      mMediaSource->SourceBufferIsActive(this)
          ->Then(mAbstractMainThread, __func__,
                 [self, this]() {
                   MSE_DEBUG("Complete AppendBuffer operation");
                   mCompletionPromise.Complete();
                   StopUpdating();
                 })
          ->Track(mCompletionPromise);
    }
  }
  if (mActive) {
    // Tell our parent decoder that we have received new data
    // and send progress event.
    mMediaSource->GetDecoder()->NotifyDataArrived();
  }

  mCurrentAttributes = aResult.second();

  CheckEndTime();

  if (!mCompletionPromise.Exists()) {
    StopUpdating();
  }
}

void SourceBuffer::AppendDataErrored(const MediaResult& aError) {
  MOZ_ASSERT(mUpdating);
  mPendingAppend.Complete();
  DDLOG(DDLogCategory::API, "AppendBuffer-error", aError);

  switch (aError.Code()) {
    case NS_ERROR_DOM_MEDIA_CANCELED:
      // Nothing further to do as the trackbuffer has been shutdown.
      // or append was aborted and abort() has handled all the events.
      break;
    default:
      AppendError(aError);
      break;
  }
}

void SourceBuffer::AppendError(const MediaResult& aDecodeError) {
  MOZ_ASSERT(NS_IsMainThread());

  ResetParserState();

  mUpdating = false;

  QueueAsyncSimpleEvent("error");
  QueueAsyncSimpleEvent("updateend");

  MOZ_ASSERT(NS_FAILED(aDecodeError));

  mMediaSource->EndOfStream(aDecodeError);

  if (mDOMPromise) {
    mDOMPromise->MaybeReject(aDecodeError);
    mDOMPromise = nullptr;
  }
}

already_AddRefed<MediaByteBuffer> SourceBuffer::PrepareAppend(
    const uint8_t* aData, uint32_t aLength, ErrorResult& aRv) {
  typedef TrackBuffersManager::EvictDataResult Result;

  if (!IsAttached() || mUpdating) {
    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
    return nullptr;
  }

  // If the HTMLMediaElement.error attribute is not null, then throw an
  // InvalidStateError exception and abort these steps.
  if (!mMediaSource->GetDecoder() ||
      mMediaSource->GetDecoder()->OwnerHasError()) {
    MSE_DEBUG("HTMLMediaElement.error is not null");
    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
    return nullptr;
  }

  if (mMediaSource->ReadyState() == MediaSourceReadyState::Ended) {
    mMediaSource->SetReadyState(MediaSourceReadyState::Open);
  }

  // Eviction uses a byte threshold. If the buffer is greater than the
  // number of bytes then data is evicted.
  // TODO: Drive evictions off memory pressure notifications.
  // TODO: Consider a global eviction threshold  rather than per TrackBuffer.
  // Give a chance to the TrackBuffersManager to evict some data if needed.
  Result evicted = mTrackBuffersManager->EvictData(
      TimeUnit::FromSeconds(mMediaSource->GetDecoder()->GetCurrentTime()),
      aLength);

  // See if we have enough free space to append our new data.
  if (evicted == Result::BUFFER_FULL) {
    aRv.Throw(NS_ERROR_DOM_QUOTA_EXCEEDED_ERR);
    return nullptr;
  }

  RefPtr<MediaByteBuffer> data = new MediaByteBuffer();
  if (!data->AppendElements(aData, aLength, fallible)) {
    aRv.Throw(NS_ERROR_DOM_QUOTA_EXCEEDED_ERR);
    return nullptr;
  }
  return data.forget();
}

double SourceBuffer::GetBufferedStart() {
  MOZ_ASSERT(NS_IsMainThread());
  ErrorResult dummy;
  RefPtr<TimeRanges> ranges = GetBuffered(dummy);
  return ranges->Length() > 0 ? ranges->GetStartTime() : 0;
}

double SourceBuffer::GetBufferedEnd() {
  MOZ_ASSERT(NS_IsMainThread());
  ErrorResult dummy;
  RefPtr<TimeRanges> ranges = GetBuffered(dummy);
  return ranges->Length() > 0 ? ranges->GetEndTime() : 0;
}

double SourceBuffer::HighestStartTime() {
  MOZ_ASSERT(NS_IsMainThread());
  return mTrackBuffersManager
             ? mTrackBuffersManager->HighestStartTime().ToSeconds()
             : 0.0;
}

double SourceBuffer::HighestEndTime() {
  MOZ_ASSERT(NS_IsMainThread());
  return mTrackBuffersManager
             ? mTrackBuffersManager->HighestEndTime().ToSeconds()
             : 0.0;
}

NS_IMPL_CYCLE_COLLECTION_CLASS(SourceBuffer)

NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(SourceBuffer)
  tmp->Detach();
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mMediaSource)
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mBuffered)
  NS_IMPL_CYCLE_COLLECTION_UNLINK(mDOMPromise)
NS_IMPL_CYCLE_COLLECTION_UNLINK_END_INHERITED(DOMEventTargetHelper)

NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(SourceBuffer,
                                                  DOMEventTargetHelper)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mMediaSource)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mBuffered)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mDOMPromise)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END

NS_IMPL_ADDREF_INHERITED(SourceBuffer, DOMEventTargetHelper)
NS_IMPL_RELEASE_INHERITED(SourceBuffer, DOMEventTargetHelper)

NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(SourceBuffer)
NS_INTERFACE_MAP_END_INHERITING(DOMEventTargetHelper)

#undef MSE_DEBUG
#undef MSE_DEBUGV
#undef MSE_API

}  // namespace dom

}  // namespace mozilla