layers/ipc/LayerTransactionParent.cpp

/* -*- 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 "LayerTransactionParent.h"
#include <vector>                           // for vector
#include "CompositableHost.h"               // for CompositableParent, Get, etc
#include "ImageLayers.h"                    // for ImageLayer
#include "Layers.h"                         // for Layer, ContainerLayer, etc
#include "CompositableTransactionParent.h"  // for EditReplyVector
#include "CompositorBridgeParent.h"
#include "mozilla/gfx/BasePoint3D.h"         // for BasePoint3D
#include "mozilla/layers/AnimationHelper.h"  // for GetAnimatedPropValue
#include "mozilla/layers/CanvasLayerComposite.h"
#include "mozilla/layers/ColorLayerComposite.h"
#include "mozilla/layers/Compositor.h"                  // for Compositor
#include "mozilla/layers/CompositorAnimationStorage.h"  // for CompositorAnimationStorage
#include "mozilla/layers/ContainerLayerComposite.h"
#include "mozilla/layers/ImageBridgeParent.h"  // for ImageBridgeParent
#include "mozilla/layers/ImageLayerComposite.h"
#include "mozilla/layers/LayerManagerComposite.h"
#include "mozilla/layers/LayersMessages.h"  // for EditReply, etc
#include "mozilla/layers/LayersTypes.h"     // for MOZ_LAYERS_LOG
#include "mozilla/layers/TextureHostOGL.h"  // for TextureHostOGL
#include "mozilla/layers/PaintedLayerComposite.h"
#include "mozilla/mozalloc.h"  // for operator delete, etc
#include "mozilla/PerfStats.h"
#include "mozilla/StaticPrefs_layers.h"
#include "mozilla/StaticPrefs_layout.h"
#include "mozilla/Telemetry.h"
#include "mozilla/Unused.h"
#include "nsCoord.h"          // for NSAppUnitsToFloatPixels
#include "nsISupportsImpl.h"  // for Layer::Release, etc
#include "nsLayoutUtils.h"    // for nsLayoutUtils
#include "nsMathUtils.h"      // for NS_round
#include "nsPoint.h"          // for nsPoint
#include "nsTArray.h"         // for nsTArray, nsTArray_Impl, etc
#include "TreeTraversal.h"    // for ForEachNode
#include "mozilla/ProfilerLabels.h"
#include "mozilla/ProfilerMarkers.h"
#include "mozilla/layers/TextureHost.h"
#include "mozilla/layers/AsyncCompositionManager.h"

using mozilla::Telemetry::LABELS_CONTENT_FRAME_TIME_REASON;

namespace mozilla {
namespace layers {

//--------------------------------------------------
// LayerTransactionParent
LayerTransactionParent::LayerTransactionParent(
    HostLayerManager* aManager, CompositorBridgeParentBase* aBridge,
    CompositorAnimationStorage* aAnimStorage, LayersId aId,
    TimeDuration aVsyncRate)
    : mLayerManager(aManager),
      mCompositorBridge(aBridge),
      mAnimStorage(aAnimStorage),
      mId(aId),
      mChildEpoch{0},
      mParentEpoch{0},
      mVsyncRate(aVsyncRate),
      mDestroyed(false),
      mIPCOpen(false),
      mUpdateHitTestingTree(false) {
  MOZ_ASSERT(mId.IsValid());
}

LayerTransactionParent::~LayerTransactionParent() = default;

void LayerTransactionParent::SetLayerManager(
    HostLayerManager* aLayerManager, CompositorAnimationStorage* aAnimStorage) {
  if (mDestroyed) {
    return;
  }
  mLayerManager = aLayerManager;
  for (const auto& layer : mLayerMap.Values()) {
    if (mAnimStorage && layer->GetCompositorAnimationsId()) {
      mAnimStorage->ClearById(layer->GetCompositorAnimationsId());
    }
    layer->AsHostLayer()->SetLayerManager(aLayerManager);
  }
  mAnimStorage = aAnimStorage;
}

mozilla::ipc::IPCResult LayerTransactionParent::RecvShutdown() {
  Destroy();
  IProtocol* mgr = Manager();
  if (!Send__delete__(this)) {
    return IPC_FAIL_NO_REASON(mgr);
  }
  return IPC_OK();
}

mozilla::ipc::IPCResult LayerTransactionParent::RecvShutdownSync() {
  return RecvShutdown();
}

void LayerTransactionParent::Destroy() {
  if (mDestroyed) {
    return;
  }
  mDestroyed = true;
  if (mAnimStorage) {
    for (const auto& layer : mLayerMap.Values()) {
      if (layer->GetCompositorAnimationsId()) {
        mAnimStorage->ClearById(layer->GetCompositorAnimationsId());
      }
      layer->Disconnect();
    }
  }
  mCompositables.clear();
  mAnimStorage = nullptr;
}

class MOZ_STACK_CLASS AutoLayerTransactionParentAsyncMessageSender final {
 public:
  explicit AutoLayerTransactionParentAsyncMessageSender(
      LayerTransactionParent* aLayerTransaction,
      const nsTArray<OpDestroy>* aDestroyActors = nullptr)
      : mLayerTransaction(aLayerTransaction), mActorsToDestroy(aDestroyActors) {
    mLayerTransaction->SetAboutToSendAsyncMessages();
  }

  ~AutoLayerTransactionParentAsyncMessageSender() {
    mLayerTransaction->SendPendingAsyncMessages();
    if (mActorsToDestroy) {
      // Destroy the actors after sending the async messages because the latter
      // may contain references to some actors.
      for (const auto& op : *mActorsToDestroy) {
        mLayerTransaction->DestroyActor(op);
      }
    }
  }

 private:
  LayerTransactionParent* mLayerTransaction;
  const nsTArray<OpDestroy>* mActorsToDestroy;
};

mozilla::ipc::IPCResult LayerTransactionParent::RecvPaintTime(
    const TransactionId& aTransactionId, const TimeDuration& aPaintTime) {
  mCompositorBridge->UpdatePaintTime(this, aPaintTime);
  return IPC_OK();
}

mozilla::ipc::IPCResult LayerTransactionParent::RecvUpdate(
    const TransactionInfo& aInfo) {
  AUTO_PROFILER_TRACING_MARKER("Paint", "LayerTransaction", GRAPHICS);
  AUTO_PROFILER_LABEL("LayerTransactionParent::RecvUpdate", GRAPHICS);
  PerfStats::AutoMetricRecording<PerfStats::Metric::LayerTransactions>
      autoRecording;

  TimeStamp updateStart = TimeStamp::Now();

  MOZ_LAYERS_LOG(
      ("[ParentSide] received txn with %zu edits", aInfo.cset().Length()));

  UpdateFwdTransactionId(aInfo.fwdTransactionId());

  if (mDestroyed || !mLayerManager || mLayerManager->IsDestroyed()) {
    for (const auto& op : aInfo.toDestroy()) {
      DestroyActor(op);
    }
    return IPC_OK();
  }

  // This ensures that destroy operations are always processed. It is not safe
  // to early-return from RecvUpdate without doing so.
  AutoLayerTransactionParentAsyncMessageSender autoAsyncMessageSender(
      this, &aInfo.toDestroy());

  {
    AutoResolveRefLayers resolve(
        mCompositorBridge->GetCompositionManager(this));
    nsCString none;
    mLayerManager->BeginTransaction(none);
  }

  // Not all edits require an update to the hit testing tree.
  mUpdateHitTestingTree = false;

  for (EditArray::index_type i = 0; i < aInfo.cset().Length(); ++i) {
    const Edit& edit = const_cast<Edit&>(aInfo.cset()[i]);

    switch (edit.type()) {
      // Create* ops
      case Edit::TOpCreatePaintedLayer: {
        MOZ_LAYERS_LOG(("[ParentSide] CreatePaintedLayer"));

        RefPtr<PaintedLayer> layer = mLayerManager->CreatePaintedLayer();
        if (!BindLayer(layer, edit.get_OpCreatePaintedLayer())) {
          return IPC_FAIL_NO_REASON(this);
        }

        UpdateHitTestingTree(layer, "CreatePaintedLayer");
        break;
      }
      case Edit::TOpCreateContainerLayer: {
        MOZ_LAYERS_LOG(("[ParentSide] CreateContainerLayer"));

        RefPtr<ContainerLayer> layer = mLayerManager->CreateContainerLayer();
        if (!BindLayer(layer, edit.get_OpCreateContainerLayer())) {
          return IPC_FAIL_NO_REASON(this);
        }

        UpdateHitTestingTree(layer, "CreateContainerLayer");
        break;
      }
      case Edit::TOpCreateImageLayer: {
        MOZ_LAYERS_LOG(("[ParentSide] CreateImageLayer"));

        RefPtr<ImageLayer> layer = mLayerManager->CreateImageLayer();
        if (!BindLayer(layer, edit.get_OpCreateImageLayer())) {
          return IPC_FAIL_NO_REASON(this);
        }

        UpdateHitTestingTree(layer, "CreateImageLayer");
        break;
      }
      case Edit::TOpCreateColorLayer: {
        MOZ_LAYERS_LOG(("[ParentSide] CreateColorLayer"));

        RefPtr<ColorLayer> layer = mLayerManager->CreateColorLayer();
        if (!BindLayer(layer, edit.get_OpCreateColorLayer())) {
          return IPC_FAIL_NO_REASON(this);
        }

        UpdateHitTestingTree(layer, "CreateColorLayer");
        break;
      }
      case Edit::TOpCreateCanvasLayer: {
        MOZ_LAYERS_LOG(("[ParentSide] CreateCanvasLayer"));

        RefPtr<CanvasLayer> layer = mLayerManager->CreateCanvasLayer();
        if (!BindLayer(layer, edit.get_OpCreateCanvasLayer())) {
          return IPC_FAIL_NO_REASON(this);
        }

        UpdateHitTestingTree(layer, "CreateCanvasLayer");
        break;
      }
      case Edit::TOpCreateRefLayer: {
        MOZ_LAYERS_LOG(("[ParentSide] CreateRefLayer"));

        RefPtr<RefLayer> layer = mLayerManager->CreateRefLayer();
        if (!BindLayer(layer, edit.get_OpCreateRefLayer())) {
          return IPC_FAIL_NO_REASON(this);
        }

        UpdateHitTestingTree(layer, "CreateRefLayer");
        break;
      }
      case Edit::TOpSetDiagnosticTypes: {
        mLayerManager->SetDiagnosticTypes(
            edit.get_OpSetDiagnosticTypes().diagnostics());
        break;
      }
      // Tree ops
      case Edit::TOpSetRoot: {
        MOZ_LAYERS_LOG(("[ParentSide] SetRoot"));

        Layer* newRoot = AsLayer(edit.get_OpSetRoot().root());
        if (!newRoot) {
          return IPC_FAIL_NO_REASON(this);
        }
        if (newRoot->GetParent()) {
          // newRoot is not a root!
          return IPC_FAIL_NO_REASON(this);
        }
        mRoot = newRoot;

        UpdateHitTestingTree(mRoot, "SetRoot");
        break;
      }
      case Edit::TOpInsertAfter: {
        MOZ_LAYERS_LOG(("[ParentSide] InsertAfter"));

        const OpInsertAfter& oia = edit.get_OpInsertAfter();
        Layer* child = AsLayer(oia.childLayer());
        Layer* layer = AsLayer(oia.container());
        Layer* after = AsLayer(oia.after());
        if (!child || !layer || !after) {
          return IPC_FAIL_NO_REASON(this);
        }
        ContainerLayer* container = layer->AsContainerLayer();
        if (!container || !container->InsertAfter(child, after)) {
          return IPC_FAIL_NO_REASON(this);
        }

        UpdateHitTestingTree(layer, "InsertAfter");
        break;
      }
      case Edit::TOpPrependChild: {
        MOZ_LAYERS_LOG(("[ParentSide] PrependChild"));

        const OpPrependChild& oac = edit.get_OpPrependChild();
        Layer* child = AsLayer(oac.childLayer());
        Layer* layer = AsLayer(oac.container());
        if (!child || !layer) {
          return IPC_FAIL_NO_REASON(this);
        }
        ContainerLayer* container = layer->AsContainerLayer();
        if (!container || !container->InsertAfter(child, nullptr)) {
          return IPC_FAIL_NO_REASON(this);
        }

        UpdateHitTestingTree(layer, "PrependChild");
        break;
      }
      case Edit::TOpRemoveChild: {
        MOZ_LAYERS_LOG(("[ParentSide] RemoveChild"));

        const OpRemoveChild& orc = edit.get_OpRemoveChild();
        Layer* childLayer = AsLayer(orc.childLayer());
        Layer* layer = AsLayer(orc.container());
        if (!childLayer || !layer) {
          return IPC_FAIL_NO_REASON(this);
        }
        ContainerLayer* container = layer->AsContainerLayer();
        if (!container || !container->RemoveChild(childLayer)) {
          return IPC_FAIL_NO_REASON(this);
        }

        UpdateHitTestingTree(layer, "RemoveChild");
        break;
      }
      case Edit::TOpRepositionChild: {
        MOZ_LAYERS_LOG(("[ParentSide] RepositionChild"));

        const OpRepositionChild& orc = edit.get_OpRepositionChild();
        Layer* child = AsLayer(orc.childLayer());
        Layer* after = AsLayer(orc.after());
        Layer* layer = AsLayer(orc.container());
        if (!child || !layer || !after) {
          return IPC_FAIL_NO_REASON(this);
        }
        ContainerLayer* container = layer->AsContainerLayer();
        if (!container || !container->RepositionChild(child, after)) {
          return IPC_FAIL_NO_REASON(this);
        }

        UpdateHitTestingTree(layer, "RepositionChild");
        break;
      }
      case Edit::TOpRaiseToTopChild: {
        MOZ_LAYERS_LOG(("[ParentSide] RaiseToTopChild"));

        const OpRaiseToTopChild& rtc = edit.get_OpRaiseToTopChild();
        Layer* child = AsLayer(rtc.childLayer());
        if (!child) {
          return IPC_FAIL_NO_REASON(this);
        }
        Layer* layer = AsLayer(rtc.container());
        if (!layer) {
          return IPC_FAIL_NO_REASON(this);
        }
        ContainerLayer* container = layer->AsContainerLayer();
        if (!container || !container->RepositionChild(child, nullptr)) {
          return IPC_FAIL_NO_REASON(this);
        }

        UpdateHitTestingTree(layer, "RaiseToTopChild");
        break;
      }
      case Edit::TCompositableOperation: {
        if (!ReceiveCompositableUpdate(edit.get_CompositableOperation())) {
          return IPC_FAIL_NO_REASON(this);
        }
        break;
      }
      case Edit::TOpAttachCompositable: {
        const OpAttachCompositable& op = edit.get_OpAttachCompositable();
        RefPtr<CompositableHost> host = FindCompositable(op.compositable());
        if (!Attach(AsLayer(op.layer()), host, false)) {
          return IPC_FAIL_NO_REASON(this);
        }
        host->SetCompositorBridgeID(mLayerManager->GetCompositorBridgeID());
        break;
      }
      case Edit::TOpAttachAsyncCompositable: {
        const OpAttachAsyncCompositable& op =
            edit.get_OpAttachAsyncCompositable();
        RefPtr<ImageBridgeParent> imageBridge =
            ImageBridgeParent::GetInstance(OtherPid());
        if (!imageBridge) {
          return IPC_FAIL_NO_REASON(this);
        }
        RefPtr<CompositableHost> host = imageBridge->FindCompositable(
            op.compositable(), /* aAllowDisablingWebRender */ true);
        if (!host) {
          // This normally should not happen, but can after a GPU process crash.
          // Media may not have had time to update the ImageContainer associated
          // with a video frame, and we may try to attach a stale
          // CompositableHandle. Rather than break the whole transaction, we
          // just continue.
          gfxCriticalNote << "CompositableHost " << op.compositable().Value()
                          << " not found";
          continue;
        }
        if (!Attach(AsLayer(op.layer()), host, true)) {
          return IPC_FAIL_NO_REASON(this);
        }
        host->SetCompositorBridgeID(mLayerManager->GetCompositorBridgeID());
        break;
      }
      default:
        MOZ_CRASH("not reached");
    }
  }

  // Process simple attribute updates.
  for (const auto& op : aInfo.setSimpleAttrs()) {
    MOZ_LAYERS_LOG(("[ParentSide] SetSimpleLayerAttributes"));
    Layer* layer = AsLayer(op.layer());
    if (!layer) {
      return IPC_FAIL_NO_REASON(this);
    }
    const SimpleLayerAttributes& attrs = op.attrs();
    const SimpleLayerAttributes& orig = layer->GetSimpleAttributes();
    if (!attrs.HitTestingInfoIsEqual(orig)) {
      UpdateHitTestingTree(layer, "scrolling info changed");
    }
    layer->SetSimpleAttributes(op.attrs());
  }

  // Process attribute updates.
  for (const auto& op : aInfo.setAttrs()) {
    MOZ_LAYERS_LOG(("[ParentSide] SetLayerAttributes"));
    if (!SetLayerAttributes(op)) {
      return IPC_FAIL_NO_REASON(this);
    }
  }

  // Process paints separately, after all normal edits.
  for (const auto& op : aInfo.paints()) {
    if (!ReceiveCompositableUpdate(op)) {
      return IPC_FAIL_NO_REASON(this);
    }
  }

  mCompositorBridge->ShadowLayersUpdated(this, aInfo, mUpdateHitTestingTree);

  {
    AutoResolveRefLayers resolve(
        mCompositorBridge->GetCompositionManager(this));
    mLayerManager->EndTransaction(TimeStamp(),
                                  LayerManager::END_NO_IMMEDIATE_REDRAW);
  }

  if (!IsSameProcess()) {
    // Ensure that any pending operations involving back and front
    // buffers have completed, so that neither process stomps on the
    // other's buffer contents.
    LayerManagerComposite::PlatformSyncBeforeReplyUpdate();
  }

#ifdef COMPOSITOR_PERFORMANCE_WARNING
  int compositeTime =
      (int)(mozilla::TimeStamp::Now() - updateStart).ToMilliseconds();
  if (compositeTime > 15) {
    printf_stderr("Compositor: Layers update took %i ms (blocking gecko).\n",
                  compositeTime);
  }
#endif

  // Enable visual warning for long transaction when draw FPS option is enabled
  bool drawFps = StaticPrefs::layers_acceleration_draw_fps();
  if (drawFps) {
    uint32_t visualWarningTrigger =
        StaticPrefs::layers_transaction_warning_ms();
    // The default theshold is 200ms to trigger, hit red when it take 4 times
    // longer
    TimeDuration latency = TimeStamp::Now() - aInfo.transactionStart();
    if (latency > TimeDuration::FromMilliseconds(visualWarningTrigger)) {
      float severity =
          (latency - TimeDuration::FromMilliseconds(visualWarningTrigger))
              .ToMilliseconds() /
          (4 * visualWarningTrigger);
      if (severity > 1.f) {
        severity = 1.f;
      }
      mLayerManager->VisualFrameWarning(severity);
      printf_stderr(
          "LayerTransactionParent::RecvUpdate transaction from process %d took "
          "%f ms",
          OtherPid(), latency.ToMilliseconds());
    }

    mLayerManager->RecordUpdateTime(
        (TimeStamp::Now() - updateStart).ToMilliseconds());
  }

  return IPC_OK();
}

bool LayerTransactionParent::SetLayerAttributes(
    const OpSetLayerAttributes& aOp) {
  Layer* layer = AsLayer(aOp.layer());
  if (!layer) {
    return false;
  }

  const LayerAttributes& attrs = aOp.attrs();
  const CommonLayerAttributes& common = attrs.common();
  if (common.visibleRegion() != layer->GetVisibleRegion()) {
    UpdateHitTestingTree(layer, "visible region changed");
    layer->SetVisibleRegion(common.visibleRegion());
  }
  if (common.eventRegions() != layer->GetEventRegions()) {
    UpdateHitTestingTree(layer, "event regions changed");
    layer->SetEventRegions(common.eventRegions());
  }
  Maybe<ParentLayerIntRect> clipRect =
      common.useClipRect() ? Some(common.clipRect()) : Nothing();
  if (clipRect != layer->GetClipRect()) {
    UpdateHitTestingTree(layer, "clip rect changed");
    layer->SetClipRect(clipRect);
  }
  if (LayerHandle maskLayer = common.maskLayer()) {
    layer->SetMaskLayer(AsLayer(maskLayer));
  } else {
    layer->SetMaskLayer(nullptr);
  }
  layer->SetCompositorAnimations(mId, common.compositorAnimations());
  // Clean up the Animations by id in the CompositorAnimationStorage
  // if there are no active animations on the layer
  if (mAnimStorage && layer->GetCompositorAnimationsId() &&
      layer->GetPropertyAnimationGroups().IsEmpty()) {
    mAnimStorage->ClearById(layer->GetCompositorAnimationsId());
  }
  if (common.scrollMetadata() != layer->GetAllScrollMetadata()) {
    UpdateHitTestingTree(layer, "scroll metadata changed");
    layer->SetScrollMetadata(common.scrollMetadata());
  }
  layer->SetDisplayListLog(common.displayListLog().get());

  // The updated invalid region is added to the existing one, since we can
  // update multiple times before the next composite.
  layer->AddInvalidRegion(common.invalidRegion());

  nsTArray<RefPtr<Layer>> maskLayers;
  for (size_t i = 0; i < common.ancestorMaskLayers().Length(); i++) {
    Layer* maskLayer = AsLayer(common.ancestorMaskLayers().ElementAt(i));
    if (!maskLayer) {
      return false;
    }
    maskLayers.AppendElement(maskLayer);
  }
  layer->SetAncestorMaskLayers(maskLayers);

  typedef SpecificLayerAttributes Specific;
  const SpecificLayerAttributes& specific = attrs.specific();
  switch (specific.type()) {
    case Specific::Tnull_t:
      break;

    case Specific::TPaintedLayerAttributes: {
      MOZ_LAYERS_LOG(("[ParentSide]   painted layer"));

      PaintedLayer* paintedLayer = layer->AsPaintedLayer();
      if (!paintedLayer) {
        return false;
      }
      const PaintedLayerAttributes& attrs =
          specific.get_PaintedLayerAttributes();

      paintedLayer->SetValidRegion(attrs.validRegion());
      break;
    }
    case Specific::TContainerLayerAttributes: {
      MOZ_LAYERS_LOG(("[ParentSide]   container layer"));

      ContainerLayer* containerLayer = layer->AsContainerLayer();
      if (!containerLayer) {
        return false;
      }
      const ContainerLayerAttributes& attrs =
          specific.get_ContainerLayerAttributes();
      containerLayer->SetPreScale(attrs.preXScale(), attrs.preYScale());
      containerLayer->SetInheritedScale(attrs.inheritedXScale(),
                                        attrs.inheritedYScale());
      containerLayer->SetScaleToResolution(attrs.presShellResolution());
      break;
    }
    case Specific::TColorLayerAttributes: {
      MOZ_LAYERS_LOG(("[ParentSide]   color layer"));

      ColorLayer* colorLayer = layer->AsColorLayer();
      if (!colorLayer) {
        return false;
      }
      colorLayer->SetColor(specific.get_ColorLayerAttributes().color().value());
      colorLayer->SetBounds(specific.get_ColorLayerAttributes().bounds());
      break;
    }
    case Specific::TCanvasLayerAttributes: {
      MOZ_LAYERS_LOG(("[ParentSide]   canvas layer"));

      CanvasLayer* canvasLayer = layer->AsCanvasLayer();
      if (!canvasLayer) {
        return false;
      }
      canvasLayer->SetSamplingFilter(
          specific.get_CanvasLayerAttributes().samplingFilter());
      canvasLayer->SetBounds(specific.get_CanvasLayerAttributes().bounds());
      break;
    }
    case Specific::TRefLayerAttributes: {
      MOZ_LAYERS_LOG(("[ParentSide]   ref layer"));

      RefLayer* refLayer = layer->AsRefLayer();
      if (!refLayer) {
        return false;
      }
      refLayer->SetReferentId(specific.get_RefLayerAttributes().id());
      refLayer->SetEventRegionsOverride(
          specific.get_RefLayerAttributes().eventRegionsOverride());
      refLayer->SetRemoteDocumentSize(
          specific.get_RefLayerAttributes().remoteDocumentSize());
      UpdateHitTestingTree(layer, "ref layer attributes changed");
      break;
    }
    case Specific::TImageLayerAttributes: {
      MOZ_LAYERS_LOG(("[ParentSide]   image layer"));

      ImageLayer* imageLayer = layer->AsImageLayer();
      if (!imageLayer) {
        return false;
      }
      const ImageLayerAttributes& attrs = specific.get_ImageLayerAttributes();
      imageLayer->SetSamplingFilter(attrs.samplingFilter());
      imageLayer->SetScaleToSize(attrs.scaleToSize(), attrs.scaleMode());
      break;
    }
    default:
      MOZ_CRASH("not reached");
  }

  return true;
}

mozilla::ipc::IPCResult LayerTransactionParent::RecvSetLayersObserverEpoch(
    const LayersObserverEpoch& aChildEpoch) {
  mChildEpoch = aChildEpoch;
  return IPC_OK();
}

bool LayerTransactionParent::ShouldParentObserveEpoch() {
  if (mParentEpoch == mChildEpoch) {
    return false;
  }

  mParentEpoch = mChildEpoch;
  return true;
}

mozilla::ipc::IPCResult LayerTransactionParent::RecvSetTestSampleTime(
    const TimeStamp& aTime) {
  if (!mCompositorBridge->SetTestSampleTime(GetId(), aTime)) {
    return IPC_FAIL_NO_REASON(this);
  }
  return IPC_OK();
}

mozilla::ipc::IPCResult LayerTransactionParent::RecvLeaveTestMode() {
  if (mDestroyed) {
    return IPC_FAIL_NO_REASON(this);
  }

  mCompositorBridge->LeaveTestMode(GetId());
  return IPC_OK();
}

mozilla::ipc::IPCResult LayerTransactionParent::RecvGetAnimationValue(
    const uint64_t& aCompositorAnimationsId, OMTAValue* aValue) {
  if (mDestroyed || !mLayerManager || mLayerManager->IsDestroyed()) {
    return IPC_FAIL_NO_REASON(this);
  }

  // Make sure we apply the latest animation style or else we can end up with
  // a race between when we temporarily clear the animation transform (in
  // CompositorBridgeParent::SetShadowProperties) and when animation
  // recalculates the value.
  mCompositorBridge->ApplyAsyncProperties(
      this, CompositorBridgeParentBase::TransformsToSkip::APZ);

  if (!mAnimStorage) {
    return IPC_FAIL_NO_REASON(this);
  }

  *aValue = mAnimStorage->GetOMTAValue(aCompositorAnimationsId);
  return IPC_OK();
}

mozilla::ipc::IPCResult LayerTransactionParent::RecvGetTransform(
    const LayerHandle& aLayerHandle, Maybe<Matrix4x4>* aTransform) {
  if (mDestroyed || !mLayerManager || mLayerManager->IsDestroyed()) {
    return IPC_FAIL_NO_REASON(this);
  }

  Layer* layer = AsLayer(aLayerHandle);
  if (!layer) {
    return IPC_FAIL_NO_REASON(this);
  }

  mCompositorBridge->ApplyAsyncProperties(
      this, CompositorBridgeParentBase::TransformsToSkip::NoneOfThem);

  Matrix4x4 transform = layer->AsHostLayer()->GetShadowBaseTransform();
  // Undo the scale transform applied by FrameTransformToTransformInDevice in
  // AsyncCompositionManager.cpp.
  if (ContainerLayer* c = layer->AsContainerLayer()) {
    transform.PostScale(1.0f / c->GetInheritedXScale(),
                        1.0f / c->GetInheritedYScale(), 1.0f);
  }
  float scale = 1;
  Point3D scaledOrigin;
  if (layer->GetTransformData()) {
    const TransformData& data = *layer->GetTransformData();
    scale = data.appUnitsPerDevPixel();
    scaledOrigin = Point3D(
        NS_round(NSAppUnitsToFloatPixels(data.origin().x, scale)),
        NS_round(NSAppUnitsToFloatPixels(data.origin().y, scale)), 0.0f);
  }

  // If our parent isn't a perspective layer, then the offset into reference
  // frame coordinates will have been applied to us. Add an inverse translation
  // to cancel it out.
  if (!layer->GetParent() || !layer->GetParent()->GetTransformIsPerspective()) {
    transform.PostTranslate(-scaledOrigin.x, -scaledOrigin.y, -scaledOrigin.z);
  }

  *aTransform = Some(transform);

  return IPC_OK();
}

mozilla::ipc::IPCResult LayerTransactionParent::RecvSetAsyncScrollOffset(
    const ScrollableLayerGuid::ViewID& aScrollID, const float& aX,
    const float& aY) {
  if (mDestroyed || !mLayerManager || mLayerManager->IsDestroyed()) {
    return IPC_FAIL_NO_REASON(this);
  }

  mCompositorBridge->SetTestAsyncScrollOffset(GetId(), aScrollID,
                                              CSSPoint(aX, aY));
  return IPC_OK();
}

mozilla::ipc::IPCResult LayerTransactionParent::RecvSetAsyncZoom(
    const ScrollableLayerGuid::ViewID& aScrollID, const float& aValue) {
  if (mDestroyed || !mLayerManager || mLayerManager->IsDestroyed()) {
    return IPC_FAIL_NO_REASON(this);
  }

  mCompositorBridge->SetTestAsyncZoom(GetId(), aScrollID,
                                      LayerToParentLayerScale(aValue));
  return IPC_OK();
}

mozilla::ipc::IPCResult LayerTransactionParent::RecvFlushApzRepaints() {
  mCompositorBridge->FlushApzRepaints(GetId());
  return IPC_OK();
}

mozilla::ipc::IPCResult LayerTransactionParent::RecvGetAPZTestData(
    APZTestData* aOutData) {
  mCompositorBridge->GetAPZTestData(GetId(), aOutData);
  return IPC_OK();
}

mozilla::ipc::IPCResult LayerTransactionParent::RecvGetFrameUniformity(
    FrameUniformityData* aOutData) {
  mCompositorBridge->GetFrameUniformity(GetId(), aOutData);
  return IPC_OK();
}

mozilla::ipc::IPCResult LayerTransactionParent::RecvRequestProperty(
    const nsString& aProperty, float* aValue) {
  *aValue = -1;
  return IPC_OK();
}

mozilla::ipc::IPCResult LayerTransactionParent::RecvSetConfirmedTargetAPZC(
    const uint64_t& aBlockId, nsTArray<ScrollableLayerGuid>&& aTargets) {
  for (size_t i = 0; i < aTargets.Length(); i++) {
    // Guard against bad data from hijacked child processes
    if (aTargets[i].mLayersId != GetId()) {
      NS_ERROR(
          "Unexpected layers id in RecvSetConfirmedTargetAPZC; dropping "
          "message...");
      return IPC_FAIL(this, "Bad layers id");
    }
  }
  mCompositorBridge->SetConfirmedTargetAPZC(GetId(), aBlockId,
                                            std::move(aTargets));
  return IPC_OK();
}

bool LayerTransactionParent::Attach(Layer* aLayer,
                                    CompositableHost* aCompositable,
                                    bool aIsAsync) {
  if (!aCompositable || !aLayer) {
    return false;
  }

  HostLayer* layer = aLayer->AsHostLayer();
  if (!layer) {
    return false;
  }

  TextureSourceProvider* provider =
      static_cast<HostLayerManager*>(aLayer->Manager())
          ->GetTextureSourceProvider();

  MOZ_ASSERT(!aCompositable->AsWebRenderImageHost());
  if (aCompositable->AsWebRenderImageHost()) {
    gfxCriticalNote << "Use WebRenderImageHost at LayerTransactionParent.";
  }
  if (!layer->SetCompositableHost(aCompositable)) {
    // not all layer types accept a compositable, see bug 967824
    return false;
  }
  aCompositable->Attach(aLayer, provider,
                        aIsAsync ? CompositableHost::ALLOW_REATTACH |
                                       CompositableHost::KEEP_ATTACHED
                                 : CompositableHost::NO_FLAGS);
  return true;
}

mozilla::ipc::IPCResult LayerTransactionParent::RecvClearCachedResources() {
  if (mRoot) {
    // NB: |mRoot| here is the *child* context's root.  In this parent
    // context, it's just a subtree root.  We need to scope the clear
    // of resources to exactly that subtree, so we specify it here.
    mLayerManager->ClearCachedResources(mRoot);
  }
  mCompositorBridge->NotifyClearCachedResources(this);
  return IPC_OK();
}

mozilla::ipc::IPCResult LayerTransactionParent::RecvScheduleComposite() {
  mCompositorBridge->ScheduleComposite(this);
  return IPC_OK();
}

void LayerTransactionParent::ActorDestroy(ActorDestroyReason why) { Destroy(); }

bool LayerTransactionParent::AllocShmem(
    size_t aSize, ipc::SharedMemory::SharedMemoryType aType,
    ipc::Shmem* aShmem) {
  if (!mIPCOpen || mDestroyed) {
    return false;
  }
  return PLayerTransactionParent::AllocShmem(aSize, aType, aShmem);
}

bool LayerTransactionParent::AllocUnsafeShmem(
    size_t aSize, ipc::SharedMemory::SharedMemoryType aType,
    ipc::Shmem* aShmem) {
  if (!mIPCOpen || mDestroyed) {
    return false;
  }

  return PLayerTransactionParent::AllocUnsafeShmem(aSize, aType, aShmem);
}

bool LayerTransactionParent::DeallocShmem(ipc::Shmem& aShmem) {
  if (!mIPCOpen || mDestroyed) {
    return false;
  }
  return PLayerTransactionParent::DeallocShmem(aShmem);
}

bool LayerTransactionParent::IsSameProcess() const {
  return OtherPid() == base::GetCurrentProcId();
}

void LayerTransactionParent::SetPendingTransactionId(
    TransactionId aId, const VsyncId& aVsyncId,
    const TimeStamp& aVsyncStartTime, const TimeStamp& aRefreshStartTime,
    const TimeStamp& aTxnStartTime, const TimeStamp& aTxnEndTime,
    bool aContainsSVG, const nsCString& aURL, const TimeStamp& aFwdTime) {
  mPendingTransactions.AppendElement(PendingTransaction{
      aId, aVsyncId, aVsyncStartTime, aRefreshStartTime, aTxnStartTime,
      aTxnEndTime, aFwdTime, aURL, aContainsSVG});
}

void LayerTransactionParent::FlushPendingTransactions(
    const VsyncId& aCompositeId, TimeStamp& aCompositeEnd,
    nsTArray<TransactionId>& aOutTransactions) {
  for (auto& transaction : mPendingTransactions) {
    aOutTransactions.AppendElement(transaction.mId);
    if (mId.IsValid() && transaction.mId.IsValid() && !mVsyncRate.IsZero()) {
      RecordContentFrameTime(
          transaction.mTxnVsyncId, transaction.mVsyncStartTime,
          transaction.mTxnStartTime, aCompositeId, aCompositeEnd,
          transaction.mTxnEndTime - transaction.mTxnStartTime, mVsyncRate,
          transaction.mContainsSVG, false);
    }

#if defined(ENABLE_FRAME_LATENCY_LOG)
    if (transaction.mId.IsValid()) {
      if (transaction.mRefreshStartTime) {
        int32_t latencyMs = lround(
            (aCompositeEnd - transaction.mRefreshStartTime).ToMilliseconds());
        printf_stderr(
            "From transaction start to end of generate frame latencyMs %d this "
            "%p\n",
            latencyMs, this);
      }
      if (transaction.mFwdTime) {
        int32_t latencyMs =
            lround((aCompositeEnd - transaction.mFwdTime).ToMilliseconds());
        printf_stderr(
            "From forwarding transaction to end of generate frame latencyMs %d "
            "this %p\n",
            latencyMs, this);
      }
    }
#endif
  }

  mPendingTransactions.Clear();
}

void LayerTransactionParent::SendAsyncMessage(
    const nsTArray<AsyncParentMessageData>& aMessage) {
  MOZ_ASSERT_UNREACHABLE("unexpected to be called");
}

void LayerTransactionParent::SendPendingAsyncMessages() {
  mCompositorBridge->SendPendingAsyncMessages();
}

void LayerTransactionParent::SetAboutToSendAsyncMessages() {
  mCompositorBridge->SetAboutToSendAsyncMessages();
}

void LayerTransactionParent::NotifyNotUsed(PTextureParent* aTexture,
                                           uint64_t aTransactionId) {
  MOZ_ASSERT_UNREACHABLE("unexpected to be called");
}

bool LayerTransactionParent::BindLayerToHandle(RefPtr<Layer> aLayer,
                                               const LayerHandle& aHandle) {
  if (!aHandle || !aLayer) {
    return false;
  }
  return mLayerMap.WithEntryHandle(aHandle.Value(), [&](auto&& entry) {
    if (entry) {
      return false;
    }
    entry.Insert(std::move(aLayer));
    return true;
  });
}

Layer* LayerTransactionParent::AsLayer(const LayerHandle& aHandle) {
  if (!aHandle) {
    return nullptr;
  }
  return mLayerMap.GetWeak(aHandle.Value());
}

mozilla::ipc::IPCResult LayerTransactionParent::RecvNewCompositable(
    const CompositableHandle& aHandle, const TextureInfo& aInfo) {
  if (!AddCompositable(aHandle, aInfo, /* aUseWebRender */ false)) {
    return IPC_FAIL_NO_REASON(this);
  }
  return IPC_OK();
}

mozilla::ipc::IPCResult LayerTransactionParent::RecvReleaseLayer(
    const LayerHandle& aHandle) {
  RefPtr<Layer> layer;
  if (!aHandle || !mLayerMap.Remove(aHandle.Value(), getter_AddRefs(layer))) {
    return IPC_FAIL_NO_REASON(this);
  }
  if (mAnimStorage && layer->GetCompositorAnimationsId()) {
    mAnimStorage->ClearById(layer->GetCompositorAnimationsId());
    layer->ClearCompositorAnimations();
  }
  layer->Disconnect();
  return IPC_OK();
}

mozilla::ipc::IPCResult LayerTransactionParent::RecvReleaseCompositable(
    const CompositableHandle& aHandle) {
  ReleaseCompositable(aHandle);
  return IPC_OK();
}

mozilla::ipc::IPCResult LayerTransactionParent::RecvRecordPaintTimes(
    const PaintTiming& aTiming) {
  // Currently we only add paint timings for remote layers. In the future
  // we could be smarter and use paint timings from the UI process, either
  // as a separate overlay or if no remote layers are attached.
  if (mLayerManager && mCompositorBridge->IsRemote()) {
    mLayerManager->RecordPaintTimes(aTiming);
  }
  return IPC_OK();
}

mozilla::ipc::IPCResult LayerTransactionParent::RecvGetTextureFactoryIdentifier(
    TextureFactoryIdentifier* aIdentifier) {
  if (mDestroyed || !mLayerManager || mLayerManager->IsDestroyed()) {
    // Default constructor sets mParentBackend to LAYERS_NONE.
    return IPC_OK();
  }

  *aIdentifier = mLayerManager->GetTextureFactoryIdentifier();
  return IPC_OK();
}

}  // namespace layers
}  // namespace mozilla