image/Decoder.cpp
author Guido Urdaneta <guidou@chromium.org>
Wed, 06 Mar 2019 12:35:06 +0000
changeset 522276 fff147f5ba18269e1d3d1dc1861718f42c4aefe0
parent 517570 bbe983a2f15e08752393bb28e8ecedebab0f1a61
child 523590 52390d9090fbd8d46b00ea29034e7039511ff8a4
permissions -rw-r--r--
Bug 1526801 [wpt PR 15292] - [PeerConnection] Fire signalingstatechange event at the right time, a=testonly Automatic update from web-platform-tests [PeerConnection] Fire signalingstatechange event at the right time Prior to this CL, the event was fired before the transceiver state was updated, in contradiction with the spec, which says it should be fired after the transceiver state is updated. Bug: 920200 Change-Id: I757cc0161a5da4888cd628619180e24a54dc732b Reviewed-on: https://chromium-review.googlesource.com/c/1458203 Commit-Queue: Guido Urdaneta <guidou@chromium.org> Reviewed-by: Henrik Boström <hbos@chromium.org> Cr-Commit-Position: refs/heads/master@{#634609} -- wpt-commits: 0f4203743c56377734f9682abb015d56d6a1a71e wpt-pr: 15292

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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 "Decoder.h"

#include "DecodePool.h"
#include "GeckoProfiler.h"
#include "IDecodingTask.h"
#include "ISurfaceProvider.h"
#include "mozilla/gfx/2D.h"
#include "mozilla/gfx/Point.h"
#include "mozilla/Telemetry.h"
#include "nsComponentManagerUtils.h"
#include "nsProxyRelease.h"
#include "nsServiceManagerUtils.h"

using mozilla::gfx::IntPoint;
using mozilla::gfx::IntRect;
using mozilla::gfx::IntSize;
using mozilla::gfx::SurfaceFormat;

namespace mozilla {
namespace image {

class MOZ_STACK_CLASS AutoRecordDecoderTelemetry final {
 public:
  explicit AutoRecordDecoderTelemetry(Decoder* aDecoder) : mDecoder(aDecoder) {
    MOZ_ASSERT(mDecoder);

    // Begin recording telemetry data.
    mStartTime = TimeStamp::Now();
  }

  ~AutoRecordDecoderTelemetry() {
    // Finish telemetry.
    mDecoder->mDecodeTime += (TimeStamp::Now() - mStartTime);
  }

 private:
  Decoder* mDecoder;
  TimeStamp mStartTime;
};

Decoder::Decoder(RasterImage* aImage)
    : mImageData(nullptr),
      mImageDataLength(0),
      mColormap(nullptr),
      mColormapSize(0),
      mImage(aImage),
      mFrameRecycler(nullptr),
      mProgress(NoProgress),
      mFrameCount(0),
      mLoopLength(FrameTimeout::Zero()),
      mDecoderFlags(DefaultDecoderFlags()),
      mSurfaceFlags(DefaultSurfaceFlags()),
      mInitialized(false),
      mMetadataDecode(false),
      mHaveExplicitOutputSize(false),
      mInFrame(false),
      mFinishedNewFrame(false),
      mHasFrameToTake(false),
      mReachedTerminalState(false),
      mDecodeDone(false),
      mError(false),
      mShouldReportError(false),
      mFinalizeFrames(true) {}

Decoder::~Decoder() {
  MOZ_ASSERT(mProgress == NoProgress || !mImage,
             "Destroying Decoder without taking all its progress changes");
  MOZ_ASSERT(mInvalidRect.IsEmpty() || !mImage,
             "Destroying Decoder without taking all its invalidations");
  mInitialized = false;

  if (mImage && !NS_IsMainThread()) {
    // Dispatch mImage to main thread to prevent it from being destructed by the
    // decode thread.
    NS_ReleaseOnMainThreadSystemGroup(mImage.forget());
  }
}

/*
 * Common implementation of the decoder interface.
 */

nsresult Decoder::Init() {
  // No re-initializing
  MOZ_ASSERT(!mInitialized, "Can't re-initialize a decoder!");

  // All decoders must have a SourceBufferIterator.
  MOZ_ASSERT(mIterator);

  // Metadata decoders must not set an output size.
  MOZ_ASSERT_IF(mMetadataDecode, !mHaveExplicitOutputSize);

  // All decoders must be anonymous except for metadata decoders.
  // XXX(seth): Soon that exception will be removed.
  MOZ_ASSERT_IF(mImage, IsMetadataDecode());

  // Implementation-specific initialization.
  nsresult rv = InitInternal();

  mInitialized = true;

  return rv;
}

LexerResult Decoder::Decode(IResumable* aOnResume /* = nullptr */) {
  MOZ_ASSERT(mInitialized, "Should be initialized here");
  MOZ_ASSERT(mIterator, "Should have a SourceBufferIterator");

  // If we're already done, don't attempt to keep decoding.
  if (GetDecodeDone()) {
    return LexerResult(HasError() ? TerminalState::FAILURE
                                  : TerminalState::SUCCESS);
  }

  LexerResult lexerResult(TerminalState::FAILURE);
  {
    AUTO_PROFILER_LABEL_CATEGORY_PAIR(GRAPHICS_ImageDecoding);
    AutoRecordDecoderTelemetry telemetry(this);

    lexerResult = DoDecode(*mIterator, aOnResume);
  };

  if (lexerResult.is<Yield>()) {
    // We either need more data to continue (in which case either @aOnResume or
    // the caller will reschedule us to run again later), or the decoder is
    // yielding to allow the caller access to some intermediate output.
    return lexerResult;
  }

  // We reached a terminal state; we're now done decoding.
  MOZ_ASSERT(lexerResult.is<TerminalState>());
  mReachedTerminalState = true;

  // If decoding failed, record that fact.
  if (lexerResult.as<TerminalState>() == TerminalState::FAILURE) {
    PostError();
  }

  // Perform final cleanup.
  CompleteDecode();

  return LexerResult(HasError() ? TerminalState::FAILURE
                                : TerminalState::SUCCESS);
}

LexerResult Decoder::TerminateFailure() {
  PostError();

  // Perform final cleanup if need be.
  if (!mReachedTerminalState) {
    mReachedTerminalState = true;
    CompleteDecode();
  }

  return LexerResult(TerminalState::FAILURE);
}

bool Decoder::ShouldSyncDecode(size_t aByteLimit) {
  MOZ_ASSERT(aByteLimit > 0);
  MOZ_ASSERT(mIterator, "Should have a SourceBufferIterator");

  return mIterator->RemainingBytesIsNoMoreThan(aByteLimit);
}

void Decoder::CompleteDecode() {
  // Implementation-specific finalization.
  nsresult rv = BeforeFinishInternal();
  if (NS_FAILED(rv)) {
    PostError();
  }

  rv = HasError() ? FinishWithErrorInternal() : FinishInternal();
  if (NS_FAILED(rv)) {
    PostError();
  }

  if (IsMetadataDecode()) {
    // If this was a metadata decode and we never got a size, the decode failed.
    if (!HasSize()) {
      PostError();
    }
    return;
  }

  // If the implementation left us mid-frame, finish that up. Note that it may
  // have left us transparent.
  if (mInFrame) {
    PostHasTransparency();
    PostFrameStop();
  }

  // If PostDecodeDone() has not been called, we may need to send teardown
  // notifications if it is unrecoverable.
  if (!mDecodeDone) {
    // We should always report an error to the console in this case.
    mShouldReportError = true;

    if (GetCompleteFrameCount() > 0) {
      // We're usable if we have at least one complete frame, so do exactly
      // what we should have when the decoder completed.
      PostHasTransparency();
      PostDecodeDone();
    } else {
      // We're not usable. Record some final progress indicating the error.
      mProgress |= FLAG_DECODE_COMPLETE | FLAG_HAS_ERROR;
    }
  }

  if (mDecodeDone) {
    MOZ_ASSERT(HasError() || mCurrentFrame, "Should have an error or a frame");

    // If this image wasn't animated and isn't a transient image, mark its frame
    // as optimizable. We don't support optimizing animated images and
    // optimizing transient images isn't worth it.
    if (!HasAnimation() &&
        !(mDecoderFlags & DecoderFlags::IMAGE_IS_TRANSIENT) && mCurrentFrame) {
      mCurrentFrame->SetOptimizable();
    }
  }
}

void Decoder::SetOutputSize(const gfx::IntSize& aSize) {
  mOutputSize = Some(aSize);
  mHaveExplicitOutputSize = true;
}

Maybe<gfx::IntSize> Decoder::ExplicitOutputSize() const {
  MOZ_ASSERT_IF(mHaveExplicitOutputSize, mOutputSize);
  return mHaveExplicitOutputSize ? mOutputSize : Nothing();
}

Maybe<uint32_t> Decoder::TakeCompleteFrameCount() {
  const bool finishedNewFrame = mFinishedNewFrame;
  mFinishedNewFrame = false;
  return finishedNewFrame ? Some(GetCompleteFrameCount()) : Nothing();
}

DecoderFinalStatus Decoder::FinalStatus() const {
  return DecoderFinalStatus(IsMetadataDecode(), GetDecodeDone(), HasError(),
                            ShouldReportError());
}

DecoderTelemetry Decoder::Telemetry() const {
  MOZ_ASSERT(mIterator);
  return DecoderTelemetry(SpeedHistogram(),
                          mIterator ? mIterator->ByteCount() : 0,
                          mIterator ? mIterator->ChunkCount() : 0, mDecodeTime);
}

nsresult Decoder::AllocateFrame(const gfx::IntSize& aOutputSize,
                                const gfx::IntRect& aFrameRect,
                                gfx::SurfaceFormat aFormat,
                                uint8_t aPaletteDepth,
                                const Maybe<AnimationParams>& aAnimParams) {
  mCurrentFrame =
      AllocateFrameInternal(aOutputSize, aFrameRect, aFormat, aPaletteDepth,
                            aAnimParams, std::move(mCurrentFrame));

  if (mCurrentFrame) {
    mHasFrameToTake = true;

    // Gather the raw pointers the decoders will use.
    mCurrentFrame->GetImageData(&mImageData, &mImageDataLength);
    mCurrentFrame->GetPaletteData(&mColormap, &mColormapSize);

    // We should now be on |aFrameNum|. (Note that we're comparing the frame
    // number, which is zero-based, with the frame count, which is one-based.)
    MOZ_ASSERT_IF(aAnimParams, aAnimParams->mFrameNum + 1 == mFrameCount);

    // If we're past the first frame, PostIsAnimated() should've been called.
    MOZ_ASSERT_IF(mFrameCount > 1, HasAnimation());

    // Update our state to reflect the new frame.
    MOZ_ASSERT(!mInFrame, "Starting new frame but not done with old one!");
    mInFrame = true;
  }

  return mCurrentFrame ? NS_OK : NS_ERROR_FAILURE;
}

RawAccessFrameRef Decoder::AllocateFrameInternal(
    const gfx::IntSize& aOutputSize, const gfx::IntRect& aFrameRect,
    SurfaceFormat aFormat, uint8_t aPaletteDepth,
    const Maybe<AnimationParams>& aAnimParams,
    RawAccessFrameRef&& aPreviousFrame) {
  if (HasError()) {
    return RawAccessFrameRef();
  }

  uint32_t frameNum = aAnimParams ? aAnimParams->mFrameNum : 0;
  if (frameNum != mFrameCount) {
    MOZ_ASSERT_UNREACHABLE("Allocating frames out of order");
    return RawAccessFrameRef();
  }

  if (aOutputSize.width <= 0 || aOutputSize.height <= 0 ||
      aFrameRect.Width() <= 0 || aFrameRect.Height() <= 0) {
    NS_WARNING("Trying to add frame with zero or negative size");
    return RawAccessFrameRef();
  }

  if (frameNum == 1) {
    MOZ_ASSERT(aPreviousFrame, "Must provide a previous frame when animated");
    aPreviousFrame->SetRawAccessOnly();
  }

  if (frameNum > 0) {
    if (ShouldBlendAnimation()) {
      if (aPreviousFrame->GetDisposalMethod() !=
          DisposalMethod::RESTORE_PREVIOUS) {
        // If the new restore frame is the direct previous frame, then we know
        // the dirty rect is composed only of the current frame's blend rect and
        // the restore frame's clear rect (if applicable) which are handled in
        // filters.
        mRestoreFrame = std::move(aPreviousFrame);
        mRestoreDirtyRect.SetBox(0, 0, 0, 0);
      } else {
        // We only need the previous frame's dirty rect, because while there may
        // have been several frames between us and mRestoreFrame, the only areas
        // that changed are the restore frame's clear rect, the current frame
        // blending rect, and the previous frame's blending rect. All else is
        // forgotten due to us restoring the same frame again.
        mRestoreDirtyRect = aPreviousFrame->GetBoundedBlendRect();
      }
    }
  }

  RawAccessFrameRef ref;

  // If we have a frame recycler, it must be for an animated image producing
  // full frames. If the higher layers are discarding frames because of the
  // memory footprint, then the recycler will allow us to reuse the buffers.
  // Each frame should be the same size and have mostly the same properties.
  if (mFrameRecycler) {
    MOZ_ASSERT(ShouldBlendAnimation());
    MOZ_ASSERT(aPaletteDepth == 0);
    MOZ_ASSERT(aAnimParams);
    MOZ_ASSERT(aFrameRect.IsEqualEdges(IntRect(IntPoint(0, 0), aOutputSize)));

    ref = mFrameRecycler->RecycleFrame(mRecycleRect);
    if (ref) {
      // If the recycled frame is actually the current restore frame, we cannot
      // use it. If the next restore frame is the new frame we are creating, in
      // theory we could reuse it, but we would need to store the restore frame
      // animation parameters elsewhere. For now we just drop it.
      bool blocked = ref.get() == mRestoreFrame.get();
      if (!blocked) {
        blocked = NS_FAILED(ref->InitForDecoderRecycle(aAnimParams.ref()));
      }

      if (blocked) {
        ref.reset();
      }
    }
  }

  // Either the recycler had nothing to give us, or we don't have a recycler.
  // Produce a new frame to store the data.
  if (!ref) {
    // There is no underlying data to reuse, so reset the recycle rect to be
    // the full frame, to ensure the restore frame is fully copied.
    mRecycleRect = IntRect(IntPoint(0, 0), aOutputSize);

    bool nonPremult = bool(mSurfaceFlags & SurfaceFlags::NO_PREMULTIPLY_ALPHA);
    auto frame = MakeNotNull<RefPtr<imgFrame>>();
    if (NS_FAILED(frame->InitForDecoder(
            aOutputSize, aFrameRect, aFormat, aPaletteDepth, nonPremult,
            aAnimParams, ShouldBlendAnimation(), bool(mFrameRecycler)))) {
      NS_WARNING("imgFrame::Init should succeed");
      return RawAccessFrameRef();
    }

    ref = frame->RawAccessRef();
    if (!ref) {
      frame->Abort();
      return RawAccessFrameRef();
    }

    if (frameNum > 0) {
      frame->SetRawAccessOnly();
    }
  }

  mFrameCount++;

  return ref;
}

/*
 * Hook stubs. Override these as necessary in decoder implementations.
 */

nsresult Decoder::InitInternal() { return NS_OK; }
nsresult Decoder::BeforeFinishInternal() { return NS_OK; }
nsresult Decoder::FinishInternal() { return NS_OK; }

nsresult Decoder::FinishWithErrorInternal() {
  MOZ_ASSERT(!mInFrame);
  return NS_OK;
}

/*
 * Progress Notifications
 */

void Decoder::PostSize(int32_t aWidth, int32_t aHeight,
                       Orientation aOrientation /* = Orientation()*/) {
  // Validate.
  MOZ_ASSERT(aWidth >= 0, "Width can't be negative!");
  MOZ_ASSERT(aHeight >= 0, "Height can't be negative!");

  // Set our intrinsic size.
  mImageMetadata.SetSize(aWidth, aHeight, aOrientation);

  // Verify it is the expected size, if given. Note that this is only used by
  // the ICO decoder for embedded image types, so only its subdecoders are
  // required to handle failures in PostSize.
  if (!IsExpectedSize()) {
    PostError();
    return;
  }

  // Set our output size if it's not already set.
  if (!mOutputSize) {
    mOutputSize = Some(IntSize(aWidth, aHeight));
  }

  MOZ_ASSERT(mOutputSize->width <= aWidth && mOutputSize->height <= aHeight,
             "Output size will result in upscaling");

  // Create a downscaler if we need to downscale. This is used by legacy
  // decoders that haven't been converted to use SurfacePipe yet.
  // XXX(seth): Obviously, we'll remove this once all decoders use SurfacePipe.
  if (mOutputSize->width < aWidth || mOutputSize->height < aHeight) {
    mDownscaler.emplace(*mOutputSize);
  }

  // Record this notification.
  mProgress |= FLAG_SIZE_AVAILABLE;
}

void Decoder::PostHasTransparency() { mProgress |= FLAG_HAS_TRANSPARENCY; }

void Decoder::PostIsAnimated(FrameTimeout aFirstFrameTimeout) {
  mProgress |= FLAG_IS_ANIMATED;
  mImageMetadata.SetHasAnimation();
  mImageMetadata.SetFirstFrameTimeout(aFirstFrameTimeout);
}

void Decoder::PostFrameStop(Opacity aFrameOpacity) {
  // We should be mid-frame
  MOZ_ASSERT(!IsMetadataDecode(), "Stopping frame during metadata decode");
  MOZ_ASSERT(mInFrame, "Stopping frame when we didn't start one");
  MOZ_ASSERT(mCurrentFrame, "Stopping frame when we don't have one");

  // Update our state.
  mInFrame = false;
  mFinishedNewFrame = true;

  mCurrentFrame->Finish(aFrameOpacity, mFinalizeFrames);

  mProgress |= FLAG_FRAME_COMPLETE;

  mLoopLength += mCurrentFrame->GetTimeout();

  if (mFrameCount == 1) {
    // If we're not sending partial invalidations, then we send an invalidation
    // here when the first frame is complete.
    if (!ShouldSendPartialInvalidations()) {
      mInvalidRect.UnionRect(mInvalidRect, IntRect(IntPoint(), Size()));
    }

    // If we dispose of the first frame by clearing it, then the first frame's
    // refresh area is all of itself. RESTORE_PREVIOUS is invalid (assumed to
    // be DISPOSE_CLEAR).
    switch (mCurrentFrame->GetDisposalMethod()) {
      default:
        MOZ_FALLTHROUGH_ASSERT("Unexpected DisposalMethod");
      case DisposalMethod::CLEAR:
      case DisposalMethod::CLEAR_ALL:
      case DisposalMethod::RESTORE_PREVIOUS:
        mFirstFrameRefreshArea = IntRect(IntPoint(), Size());
        break;
      case DisposalMethod::KEEP:
      case DisposalMethod::NOT_SPECIFIED:
        break;
    }
  } else {
    // Some GIFs are huge but only have a small area that they animate. We only
    // need to refresh that small area when frame 0 comes around again.
    mFirstFrameRefreshArea.UnionRect(mFirstFrameRefreshArea,
                                     mCurrentFrame->GetBoundedBlendRect());
  }
}

void Decoder::PostInvalidation(const gfx::IntRect& aRect,
                               const Maybe<gfx::IntRect>& aRectAtOutputSize
                               /* = Nothing() */) {
  // We should be mid-frame
  MOZ_ASSERT(mInFrame, "Can't invalidate when not mid-frame!");
  MOZ_ASSERT(mCurrentFrame, "Can't invalidate when not mid-frame!");

  // Record this invalidation, unless we're not sending partial invalidations
  // or we're past the first frame.
  if (ShouldSendPartialInvalidations() && mFrameCount == 1) {
    mInvalidRect.UnionRect(mInvalidRect, aRect);
    mCurrentFrame->ImageUpdated(aRectAtOutputSize.valueOr(aRect));
  }
}

void Decoder::PostDecodeDone(int32_t aLoopCount /* = 0 */) {
  MOZ_ASSERT(!IsMetadataDecode(), "Done with decoding in metadata decode");
  MOZ_ASSERT(!mInFrame, "Can't be done decoding if we're mid-frame!");
  MOZ_ASSERT(!mDecodeDone, "Decode already done!");
  mDecodeDone = true;

  mImageMetadata.SetLoopCount(aLoopCount);

  // Some metadata that we track should take into account every frame in the
  // image. If this is a first-frame-only decode, our accumulated loop length
  // and first frame refresh area only includes the first frame, so it's not
  // correct and we don't record it.
  if (!IsFirstFrameDecode()) {
    mImageMetadata.SetLoopLength(mLoopLength);
    mImageMetadata.SetFirstFrameRefreshArea(mFirstFrameRefreshArea);
  }

  mProgress |= FLAG_DECODE_COMPLETE;
}

void Decoder::PostError() {
  mError = true;

  if (mInFrame) {
    MOZ_ASSERT(mCurrentFrame);
    MOZ_ASSERT(mFrameCount > 0);
    mCurrentFrame->Abort();
    mInFrame = false;
    --mFrameCount;
    mHasFrameToTake = false;
  }
}

}  // namespace image
}  // namespace mozilla