tor-browser

APZTaskRunnable.cpp (6177B)

---

/* -*- 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 "APZTaskRunnable.h"

#include "mozilla/PresShell.h"
#include "nsRefreshDriver.h"

namespace mozilla::layers {

NS_IMETHODIMP
APZTaskRunnable::Run() {
 if (!mController) {
   mRegisteredPresShellId = 0;
   return NS_OK;
 }

 // Move these variables first since below RequestContentPaint and
 // NotifyFlushComplete might spin event loop so that any new incoming requests
 // will be properly queued and run in the next refresh driver's tick.
 const bool needsFlushCompleteNotification = mNeedsFlushCompleteNotification;
 auto requests = std::move(mPendingRequestQueue);
 mPendingRepaintRequestMap.clear();
 mNeedsFlushCompleteNotification = false;
 mRegisteredPresShellId = 0;
 RefPtr<GeckoContentController> controller = mController;

 // We need to process pending RepaintRequests first.
 while (!requests.empty()) {
   struct RequestProcessor {
     GeckoContentController* mController;
     void operator()(const RepaintRequest& aRequest) {
       mController->RequestContentRepaint(aRequest);
     }
     void operator()(const APZStateChangeRequest& aRequest) {
       mController->NotifyAPZStateChange(aRequest.mGuid, aRequest.mChange,
                                         aRequest.mArg,
                                         aRequest.mInputBlockId);
     }
   };
   requests.front().match(RequestProcessor{controller.get()});
   requests.pop_front();
 }

 if (needsFlushCompleteNotification) {
   // Then notify "apz-repaints-flushed" so that we can ensure that all pending
   // scroll position updates have finished when the "apz-repaints-flushed"
   // arrives.
   controller->NotifyFlushComplete();
 }

 return NS_OK;
}

void APZTaskRunnable::QueueRequest(const RepaintRequest& aRequest) {
 // If we are in test-controlled refreshes mode, process this |aRequest|
 // synchronously.
 if (IsTestControllingRefreshesEnabled()) {
   // Flush all pending requests and notification just in case the refresh
   // driver mode was changed before flushing them.
   RefPtr<GeckoContentController> controller = mController;
   Run();
   controller->RequestContentRepaint(aRequest);
   return;
 }
 EnsureRegisterAsEarlyRunner();

 RepaintRequestKey key{aRequest.GetScrollId(), aRequest.GetScrollUpdateType()};

 auto lastDiscardableRequest = mPendingRepaintRequestMap.find(key);
 // If there's an existing request with the same key, we can discard it and we
 // push the incoming one into the queue's tail so that we can ensure the order
 // of processing requests.
 if (lastDiscardableRequest != mPendingRepaintRequestMap.end()) {
   for (auto it = mPendingRequestQueue.begin();
        it != mPendingRequestQueue.end(); it++) {
     if (it->is<RepaintRequest>()) {
       const RepaintRequest& request = it->as<RepaintRequest>();
       if (RepaintRequestKey{request.GetScrollId(),
                             request.GetScrollUpdateType()} == key) {
         mPendingRequestQueue.erase(it);
         break;
       }
     }
   }
 }
 mPendingRepaintRequestMap.insert(key);
 mPendingRequestQueue.push_back(AsVariant(aRequest));
}

void APZTaskRunnable::QueueAPZStateChange(const ScrollableLayerGuid& aGuid,
                                         const APZStateChange& aChange,
                                         const int& aArg,
                                         Maybe<uint64_t> aInputBlockId) {
 // If we are in test-controlled refreshes mode, process this |aRequest|
 // synchronously.
 if (IsTestControllingRefreshesEnabled()) {
   // Flush all pending requests and notification just in case the refresh
   // driver mode was changed before flushing them.
   RefPtr<GeckoContentController> controller = mController;
   Run();
   controller->NotifyAPZStateChange(aGuid, aChange, aArg, aInputBlockId);
   return;
 }
 EnsureRegisterAsEarlyRunner();

 mPendingRequestQueue.push_back(
     AsVariant(APZStateChangeRequest{aGuid, aChange, aArg, aInputBlockId}));
}

void APZTaskRunnable::QueueFlushCompleteNotification() {
 // If we are in test-controlled refreshes mode, notify apz-repaints-flushed
 // synchronously.
 if (IsTestControllingRefreshesEnabled()) {
   // Flush all pending requests and notification just in case the refresh
   // driver mode was changed before flushing them.
   RefPtr<GeckoContentController> controller = mController;
   Run();
   controller->NotifyFlushComplete();
   return;
 }

 EnsureRegisterAsEarlyRunner();

 mNeedsFlushCompleteNotification = true;
}

bool APZTaskRunnable::IsRegisteredWithCurrentPresShell() const {
 MOZ_ASSERT(mController);

 uint32_t current = 0;
 if (PresShell* presShell = mController->GetTopLevelPresShell()) {
   current = presShell->GetPresShellId();
 }
 return mRegisteredPresShellId == current;
}

void APZTaskRunnable::EnsureRegisterAsEarlyRunner() {
 if (IsRegisteredWithCurrentPresShell()) {
   return;
 }

 // If the registered presshell id has been changed, we need to discard pending
 // requests and notification since all of them are for documents which
 // have been torn down.
 if (mRegisteredPresShellId) {
   mPendingRepaintRequestMap.clear();
   mPendingRequestQueue.clear();
   mNeedsFlushCompleteNotification = false;
 }

 if (PresShell* presShell = mController->GetTopLevelPresShell()) {
   if (nsRefreshDriver* driver = presShell->GetRefreshDriver()) {
     driver->AddEarlyRunner(this);
     mRegisteredPresShellId = presShell->GetPresShellId();
   }
 }
}

bool APZTaskRunnable::IsTestControllingRefreshesEnabled() const {
 if (!mController) {
   return false;
 }

 if (PresShell* presShell = mController->GetTopLevelPresShell()) {
   if (nsRefreshDriver* driver = presShell->GetRefreshDriver()) {
     return driver->IsTestControllingRefreshesEnabled();
   }
 }
 return false;
}

}  // namespace mozilla::layers