The Tor Browser: content/base/src/nsDOMMutationObserver.cpp@deefc01c0e14 (annotated)

content/base/src/nsDOMMutationObserver.cpp@deefc01c0e14 (annotated)

content/base/src/nsDOMMutationObserver.cpp

Thu, 15 Jan 2015 21:03:48 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 15 Jan 2015 21:03:48 +0100
branch: TOR_BUG_9701
changeset 11: deefc01c0e14
permissions: -rw-r--r--

Integrate friendly tips from Tor colleagues to make (or not) 4.5 alpha 3;
This includes removal of overloaded (but unused) methods, and addition of
a overlooked call to DataStruct::SetData(nsISupports, uint32_t, bool.)

 /* -*- Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil; tab-width: 8; -*- */
 /* vim: set sw=4 ts=8 et 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 "nsDOMMutationObserver.h"
 #include "mozilla/dom/OwningNonNull.h"
 #include "nsError.h"
 #include "nsIScriptGlobalObject.h"
 #include "nsContentUtils.h"
 #include "nsThreadUtils.h"
 #include "nsIDOMMutationEvent.h"
 #include "nsTextFragment.h"
 #include "nsServiceManagerUtils.h"
 nsAutoTArray<nsRefPtr<nsDOMMutationObserver>, 4>*
   nsDOMMutationObserver::sScheduledMutationObservers = nullptr;
 nsDOMMutationObserver* nsDOMMutationObserver::sCurrentObserver = nullptr;
 uint32_t nsDOMMutationObserver::sMutationLevel = 0;
 uint64_t nsDOMMutationObserver::sCount = 0;
 nsAutoTArray<nsAutoTArray<nsRefPtr<nsDOMMutationObserver>, 4>, 4>*
 nsDOMMutationObserver::sCurrentlyHandlingObservers = nullptr;
 nsINodeList*
 nsDOMMutationRecord::AddedNodes()
 {
   if (!mAddedNodes) {
     mAddedNodes = new nsSimpleContentList(mTarget);
   }
   return mAddedNodes;
 }
 nsINodeList*
 nsDOMMutationRecord::RemovedNodes()
 {
   if (!mRemovedNodes) {
     mRemovedNodes = new nsSimpleContentList(mTarget);
   }
   return mRemovedNodes;
 }
 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(nsDOMMutationRecord)
   NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
   NS_INTERFACE_MAP_ENTRY(nsISupports)
 NS_INTERFACE_MAP_END
 NS_IMPL_CYCLE_COLLECTING_ADDREF(nsDOMMutationRecord)
 NS_IMPL_CYCLE_COLLECTING_RELEASE(nsDOMMutationRecord)
 NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE_7(nsDOMMutationRecord,
                                         mTarget,
                                         mPreviousSibling, mNextSibling,
                                         mAddedNodes, mRemovedNodes,
                                         mNext, mOwner)
 // Observer
 NS_IMPL_ADDREF(nsMutationReceiver)
 NS_IMPL_RELEASE(nsMutationReceiver)
 NS_INTERFACE_MAP_BEGIN(nsMutationReceiver)
   NS_INTERFACE_MAP_ENTRY(nsISupports)
   NS_INTERFACE_MAP_ENTRY(nsIMutationObserver)
 NS_INTERFACE_MAP_END
 nsMutationReceiver::nsMutationReceiver(nsINode* aTarget,
                                        nsDOMMutationObserver* aObserver)
 : nsMutationReceiverBase(aTarget, aObserver)
 {
   mTarget->BindObject(aObserver);
 }
 void
 nsMutationReceiver::Disconnect(bool aRemoveFromObserver)
 {
   if (mRegisterTarget) {
     mRegisterTarget->RemoveMutationObserver(this);
     mRegisterTarget = nullptr;
   }
   mParent = nullptr;
   nsINode* target = mTarget;
   mTarget = nullptr;
   nsDOMMutationObserver* observer = mObserver;
   mObserver = nullptr;
   RemoveClones();
   if (target && observer) {
     if (aRemoveFromObserver) {
       static_cast<nsDOMMutationObserver*>(observer)->RemoveReceiver(this);
     }
     // UnbindObject may delete 'this'!
     target->UnbindObject(observer);
   }
 }
 void
 nsMutationReceiver::AttributeWillChange(nsIDocument* aDocument,
                                         mozilla::dom::Element* aElement,
                                         int32_t aNameSpaceID,
                                         nsIAtom* aAttribute,
                                         int32_t aModType)
 {
   if (nsAutoMutationBatch::IsBatching() ||
       !ObservesAttr(aElement, aNameSpaceID, aAttribute) ||
       aElement->ChromeOnlyAccess()) {
     return;
   }
   nsDOMMutationRecord* m =
     Observer()->CurrentRecord(nsGkAtoms::attributes);
   NS_ASSERTION(!m->mTarget || m->mTarget == aElement,
                "Wrong target!");
   NS_ASSERTION(!m->mAttrName || m->mAttrName == aAttribute,
                "Wrong attribute!");
   if (!m->mTarget) {
     m->mTarget = aElement;
     m->mAttrName = aAttribute;
     if (aNameSpaceID == kNameSpaceID_None) {
       m->mAttrNamespace.SetIsVoid(true);
     } else {
       nsContentUtils::NameSpaceManager()->GetNameSpaceURI(aNameSpaceID,
                                                           m->mAttrNamespace);
     }
   }
   if (AttributeOldValue() && m->mPrevValue.IsVoid()) {
     if (!aElement->GetAttr(aNameSpaceID, aAttribute, m->mPrevValue)) {
       m->mPrevValue.SetIsVoid(true);
     }
   }
 }
 void
 nsMutationReceiver::CharacterDataWillChange(nsIDocument *aDocument,
                                             nsIContent* aContent,
                                             CharacterDataChangeInfo* aInfo)
 {
   if (nsAutoMutationBatch::IsBatching() ||
       !CharacterData() || !(Subtree() || aContent == Target()) ||
       aContent->ChromeOnlyAccess()) {
     return;
   }
   nsDOMMutationRecord* m =
     Observer()->CurrentRecord(nsGkAtoms::characterData);
   NS_ASSERTION(!m->mTarget || m->mTarget == aContent,
                "Wrong target!");
   if (!m->mTarget) {
     m->mTarget = aContent;
   }
   if (CharacterDataOldValue() && m->mPrevValue.IsVoid()) {
     aContent->GetText()->AppendTo(m->mPrevValue);
   }
 }
 void
 nsMutationReceiver::ContentAppended(nsIDocument* aDocument,
                                     nsIContent* aContainer,
                                     nsIContent* aFirstNewContent,
                                     int32_t aNewIndexInContainer)
 {
   nsINode* parent = NODE_FROM(aContainer, aDocument);
   bool wantsChildList = ChildList() && (Subtree() || parent == Target());
   if (!wantsChildList || aFirstNewContent->ChromeOnlyAccess()) {
     return;
   }
   if (nsAutoMutationBatch::IsBatching()) {
     if (parent == nsAutoMutationBatch::GetBatchTarget()) {
       nsAutoMutationBatch::UpdateObserver(Observer(), wantsChildList);
     }
     return;
   }
   nsDOMMutationRecord* m =
     Observer()->CurrentRecord(nsGkAtoms::childList);
   NS_ASSERTION(!m->mTarget || m->mTarget == parent,
                "Wrong target!");
   if (m->mTarget) {
     // Already handled case.
     return;
   }
   m->mTarget = parent;
   m->mAddedNodes = new nsSimpleContentList(parent);
   nsINode* n = aFirstNewContent;
   while (n) {
     m->mAddedNodes->AppendElement(static_cast<nsIContent*>(n));
     n = n->GetNextSibling();
   }
   m->mPreviousSibling = aFirstNewContent->GetPreviousSibling();
 }
 void
 nsMutationReceiver::ContentInserted(nsIDocument* aDocument,
                                     nsIContent* aContainer,
                                     nsIContent* aChild,
                                     int32_t aIndexInContainer)
 {
   nsINode* parent = NODE_FROM(aContainer, aDocument);
   bool wantsChildList = ChildList() && (Subtree() || parent == Target());
   if (!wantsChildList || aChild->ChromeOnlyAccess()) {
     return;
   }
   if (nsAutoMutationBatch::IsBatching()) {
     if (parent == nsAutoMutationBatch::GetBatchTarget()) {
       nsAutoMutationBatch::UpdateObserver(Observer(), wantsChildList);
     }
     return;
   }
   nsDOMMutationRecord* m =
     Observer()->CurrentRecord(nsGkAtoms::childList);
   if (m->mTarget) {
     // Already handled case.
     return;
   }
   m->mTarget = parent;
   m->mAddedNodes = new nsSimpleContentList(parent);
   m->mAddedNodes->AppendElement(aChild);
   m->mPreviousSibling = aChild->GetPreviousSibling();
   m->mNextSibling = aChild->GetNextSibling();
 }
 void
 nsMutationReceiver::ContentRemoved(nsIDocument* aDocument,
                                    nsIContent* aContainer,
                                    nsIContent* aChild,
                                    int32_t aIndexInContainer,
                                    nsIContent* aPreviousSibling)
 {
   if (aChild->ChromeOnlyAccess()) {
     return;
   }
   nsINode* parent = NODE_FROM(aContainer, aDocument);
   if (nsAutoMutationBatch::IsBatching()) {
     if (nsAutoMutationBatch::IsRemovalDone()) {
       // This can happen for example if HTML parser parses to
       // context node, but needs to move elements around.
       return;
     }
     if (nsAutoMutationBatch::GetBatchTarget() != parent) {
       return;
     }
     bool wantsChildList = ChildList() && (Subtree() || parent == Target());
     if (wantsChildList || Subtree()) {
       nsAutoMutationBatch::NodeRemoved(aChild);
       nsAutoMutationBatch::UpdateObserver(Observer(), wantsChildList);
     }
     return;
   }
   if (Subtree()) {
     // Try to avoid creating transient observer if the node
     // already has an observer observing the same set of nodes.
     nsMutationReceiver* orig = GetParent() ? GetParent() : this;
     if (Observer()->GetReceiverFor(aChild, false) != orig) {
       bool transientExists = false;
       nsCOMArray<nsMutationReceiver>* transientReceivers = nullptr;
       Observer()->mTransientReceivers.Get(aChild, &transientReceivers);
       if (!transientReceivers) {
         transientReceivers = new nsCOMArray<nsMutationReceiver>();
         Observer()->mTransientReceivers.Put(aChild, transientReceivers);
       } else {
         for (int32_t i = 0; i < transientReceivers->Count(); ++i) {
           nsMutationReceiver* r = transientReceivers->ObjectAt(i);
           if (r->GetParent() == orig) {
             transientExists = true;
           }
         }
       }
       if (!transientExists) {
         // Make sure the elements which are removed from the
         // subtree are kept in the same observation set.
         transientReceivers->AppendObject(new nsMutationReceiver(aChild, orig));
       }
     }
   }
   if (ChildList() && (Subtree() || parent == Target())) {
     nsDOMMutationRecord* m =
       Observer()->CurrentRecord(nsGkAtoms::childList);
     if (m->mTarget) {
       // Already handled case.
       return;
     }
     m->mTarget = parent;
     m->mRemovedNodes = new nsSimpleContentList(parent);
     m->mRemovedNodes->AppendElement(aChild);
     m->mPreviousSibling = aPreviousSibling;
     m->mNextSibling = parent->GetChildAt(aIndexInContainer);
   }
   // We need to schedule always, so that after microtask mTransientReceivers
   // can be cleared correctly.
   Observer()->ScheduleForRun();
 }
 void nsMutationReceiver::NodeWillBeDestroyed(const nsINode *aNode)
 {
   NS_ASSERTION(!mParent, "Shouldn't have mParent here!");
   Disconnect(true);
 }
 // Observer
 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(nsDOMMutationObserver)
   NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
   NS_INTERFACE_MAP_ENTRY(nsISupports)
   NS_INTERFACE_MAP_ENTRY(nsDOMMutationObserver)
 NS_INTERFACE_MAP_END
 NS_IMPL_CYCLE_COLLECTING_ADDREF(nsDOMMutationObserver)
 NS_IMPL_CYCLE_COLLECTING_RELEASE(nsDOMMutationObserver)
 NS_IMPL_CYCLE_COLLECTION_CLASS(nsDOMMutationObserver)
 NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN(nsDOMMutationObserver)
   NS_IMPL_CYCLE_COLLECTION_TRACE_PRESERVED_WRAPPER
 NS_IMPL_CYCLE_COLLECTION_TRACE_END
 NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(nsDOMMutationObserver)
   NS_IMPL_CYCLE_COLLECTION_UNLINK_PRESERVED_WRAPPER
   NS_IMPL_CYCLE_COLLECTION_UNLINK(mOwner)
   for (int32_t i = 0; i < tmp->mReceivers.Count(); ++i) {
     tmp->mReceivers[i]->Disconnect(false);
   }
   tmp->mReceivers.Clear();
   tmp->ClearPendingRecords();
   NS_IMPL_CYCLE_COLLECTION_UNLINK(mCallback)
   // No need to handle mTransientReceivers
   NS_IMPL_CYCLE_COLLECTION_UNLINK_END
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(nsDOMMutationObserver)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE_SCRIPT_OBJECTS
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mOwner)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mReceivers)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mFirstPendingMutation)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mCallback)
   // No need to handle mTransientReceivers
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
 nsMutationReceiver*
 nsDOMMutationObserver::GetReceiverFor(nsINode* aNode, bool aMayCreate)
 {
   if (!aMayCreate && !aNode->MayHaveDOMMutationObserver()) {
     return nullptr;
   }
   for (int32_t i = 0; i < mReceivers.Count(); ++i) {
     if (mReceivers[i]->Target() == aNode) {
       return mReceivers[i];
     }
   }
   if (!aMayCreate) {
     return nullptr;
   }
   nsMutationReceiver* r = new nsMutationReceiver(aNode, this);
   mReceivers.AppendObject(r);
   return r;
 }
 void
 nsDOMMutationObserver::RemoveReceiver(nsMutationReceiver* aReceiver)
 {
   mReceivers.RemoveObject(aReceiver);
 }
 void
 nsDOMMutationObserver::GetAllSubtreeObserversFor(nsINode* aNode,
                                                  nsTArray<nsMutationReceiver*>&
                                                    aReceivers)
 {
   nsINode* n = aNode;
   while (n) {
     if (n->MayHaveDOMMutationObserver()) {
       nsMutationReceiver* r = GetReceiverFor(n, false);
       if (r && r->Subtree() && !aReceivers.Contains(r)) {
         aReceivers.AppendElement(r);
         // If we've found all the receivers the observer has,
         // no need to search for more.
         if (mReceivers.Count() == int32_t(aReceivers.Length())) {
           return;
         }
       }
       nsCOMArray<nsMutationReceiver>* transientReceivers = nullptr;
       if (mTransientReceivers.Get(n, &transientReceivers) && transientReceivers) {
         for (int32_t i = 0; i < transientReceivers->Count(); ++i) {
           nsMutationReceiver* r = transientReceivers->ObjectAt(i);
           nsMutationReceiver* parent = r->GetParent();
           if (r->Subtree() && parent && !aReceivers.Contains(parent)) {
             aReceivers.AppendElement(parent);
           }
         }
         if (mReceivers.Count() == int32_t(aReceivers.Length())) {
           return;
         }
       }
     }
     n = n->GetParentNode();
   }
 }
 void
 nsDOMMutationObserver::ScheduleForRun()
 {
   nsDOMMutationObserver::AddCurrentlyHandlingObserver(this);
   if (mWaitingForRun) {
     return;
   }
   mWaitingForRun = true;
   RescheduleForRun();
 }
 void
 nsDOMMutationObserver::RescheduleForRun()
 {
   if (!sScheduledMutationObservers) {
     sScheduledMutationObservers = new nsAutoTArray<nsRefPtr<nsDOMMutationObserver>, 4>;
   }
   bool didInsert = false;
   for (uint32_t i = 0; i < sScheduledMutationObservers->Length(); ++i) {
     if (static_cast<nsDOMMutationObserver*>((*sScheduledMutationObservers)[i])
           ->mId > mId) {
       sScheduledMutationObservers->InsertElementAt(i, this);
       didInsert = true;
       break;
     }
   }
   if (!didInsert) {
     sScheduledMutationObservers->AppendElement(this);
   }
 }
 void
 nsDOMMutationObserver::Observe(nsINode& aTarget,
                                const mozilla::dom::MutationObserverInit& aOptions,
                                mozilla::ErrorResult& aRv)
 {
   if (!(aOptions.mChildList || aOptions.mAttributes || aOptions.mCharacterData)) {
     aRv.Throw(NS_ERROR_DOM_SYNTAX_ERR);
     return;
   }
   if (aOptions.mAttributeOldValue && !aOptions.mAttributes) {
     aRv.Throw(NS_ERROR_DOM_SYNTAX_ERR);
     return;
   }
   if (aOptions.mCharacterDataOldValue && !aOptions.mCharacterData) {
     aRv.Throw(NS_ERROR_DOM_SYNTAX_ERR);
     return;
   }
   nsCOMArray<nsIAtom> filters;
   bool allAttrs = true;
   if (aOptions.mAttributeFilter.WasPassed()) {
     allAttrs = false;
     const mozilla::dom::Sequence<nsString>& filtersAsString =
       aOptions.mAttributeFilter.Value();
     uint32_t len = filtersAsString.Length();
     if (len != 0 && !aOptions.mAttributes) {
       aRv.Throw(NS_ERROR_DOM_SYNTAX_ERR);
       return;
     }
     filters.SetCapacity(len);
     for (uint32_t i = 0; i < len; ++i) {
       nsCOMPtr<nsIAtom> a = do_GetAtom(filtersAsString[i]);
       filters.AppendObject(a);
     }
   }
   nsMutationReceiver* r = GetReceiverFor(&aTarget, true);
   r->SetChildList(aOptions.mChildList);
   r->SetAttributes(aOptions.mAttributes);
   r->SetCharacterData(aOptions.mCharacterData);
   r->SetSubtree(aOptions.mSubtree);
   r->SetAttributeOldValue(aOptions.mAttributeOldValue);
   r->SetCharacterDataOldValue(aOptions.mCharacterDataOldValue);
   r->SetAttributeFilter(filters);
   r->SetAllAttributes(allAttrs);
   r->RemoveClones();
 #ifdef DEBUG
   for (int32_t i = 0; i < mReceivers.Count(); ++i) {
     NS_WARN_IF_FALSE(mReceivers[i]->Target(),
                      "All the receivers should have a target!");
   }
 #endif
 }
 void
 nsDOMMutationObserver::Disconnect()
 {
   for (int32_t i = 0; i < mReceivers.Count(); ++i) {
     mReceivers[i]->Disconnect(false);
   }
   mReceivers.Clear();
   mCurrentMutations.Clear();
   ClearPendingRecords();
 }
 void
 nsDOMMutationObserver::TakeRecords(
                          nsTArray<nsRefPtr<nsDOMMutationRecord> >& aRetVal)
 {
   aRetVal.Clear();
   aRetVal.SetCapacity(mPendingMutationCount);
   nsRefPtr<nsDOMMutationRecord> current;
   current.swap(mFirstPendingMutation);
   for (uint32_t i = 0; i < mPendingMutationCount; ++i) {
     nsRefPtr<nsDOMMutationRecord> next;
     current->mNext.swap(next);
     *aRetVal.AppendElement() = current.forget();
     current.swap(next);
   }
   ClearPendingRecords();
 }
 void
 nsDOMMutationObserver::GetObservingInfo(nsTArray<Nullable<MutationObservingInfo> >& aResult)
 {
   aResult.SetCapacity(mReceivers.Count());
   for (int32_t i = 0; i < mReceivers.Count(); ++i) {
     MutationObservingInfo& info = aResult.AppendElement()->SetValue();
     nsMutationReceiver* mr = mReceivers[i];
     info.mChildList = mr->ChildList();
     info.mAttributes = mr->Attributes();
     info.mCharacterData = mr->CharacterData();
     info.mSubtree = mr->Subtree();
     info.mAttributeOldValue = mr->AttributeOldValue();
     info.mCharacterDataOldValue = mr->CharacterDataOldValue();
     nsCOMArray<nsIAtom>& filters = mr->AttributeFilter();
     if (filters.Count()) {
       info.mAttributeFilter.Construct();
       mozilla::dom::Sequence<nsString>& filtersAsStrings =
         info.mAttributeFilter.Value();
       for (int32_t j = 0; j < filters.Count(); ++j) {
         filtersAsStrings.AppendElement(nsDependentAtomString(filters[j]));
       }
     }
     info.mObservedNode = mr->Target();
   }
 }
 // static
 already_AddRefed<nsDOMMutationObserver>
 nsDOMMutationObserver::Constructor(const mozilla::dom::GlobalObject& aGlobal,
                                    mozilla::dom::MutationCallback& aCb,
                                    mozilla::ErrorResult& aRv)
 {
   nsCOMPtr<nsPIDOMWindow> window = do_QueryInterface(aGlobal.GetAsSupports());
   if (!window) {
     aRv.Throw(NS_ERROR_FAILURE);
     return nullptr;
   }
   MOZ_ASSERT(window->IsInnerWindow());
   nsRefPtr<nsDOMMutationObserver> observer =
     new nsDOMMutationObserver(window.forget(), aCb);
   return observer.forget();
 }
 void
 nsDOMMutationObserver::HandleMutation()
 {
   NS_ASSERTION(nsContentUtils::IsSafeToRunScript(), "Whaat!");
   NS_ASSERTION(mCurrentMutations.IsEmpty(),
                "Still generating MutationRecords?");
   mWaitingForRun = false;
   for (int32_t i = 0; i < mReceivers.Count(); ++i) {
     mReceivers[i]->RemoveClones();
   }
   mTransientReceivers.Clear();
   nsPIDOMWindow* outer = mOwner->GetOuterWindow();
   if (!mPendingMutationCount || !outer ||
       outer->GetCurrentInnerWindow() != mOwner) {
     ClearPendingRecords();
     return;
   }
   mozilla::dom::Sequence<mozilla::dom::OwningNonNull<nsDOMMutationRecord> >
     mutations;
   if (mutations.SetCapacity(mPendingMutationCount)) {
     // We can't use TakeRecords easily here, because it deals with a
     // different type of array, and we want to optimize out any extra copying.
     nsRefPtr<nsDOMMutationRecord> current;
     current.swap(mFirstPendingMutation);
     for (uint32_t i = 0; i < mPendingMutationCount; ++i) {
       nsRefPtr<nsDOMMutationRecord> next;
       current->mNext.swap(next);
       *mutations.AppendElement() = current;
       current.swap(next);
     }
   }
   ClearPendingRecords();
   mozilla::ErrorResult rv;
   mCallback->Call(this, mutations, *this, rv);
 }
 class AsyncMutationHandler : public nsRunnable
 {
 public:
   NS_IMETHOD Run()
   {
     nsDOMMutationObserver::HandleMutations();
     return NS_OK;
   }
 };
 void
 nsDOMMutationObserver::HandleMutationsInternal()
 {
   if (!nsContentUtils::IsSafeToRunScript()) {
     nsContentUtils::AddScriptRunner(new AsyncMutationHandler());
     return;
   }
   static nsRefPtr<nsDOMMutationObserver> sCurrentObserver;
   if (sCurrentObserver && !sCurrentObserver->Suppressed()) {
     // In normal cases sScheduledMutationObservers will be handled
     // after previous mutations are handled. But in case some
     // callback calls a sync API, which spins the eventloop, we need to still
     // process other mutations happening during that sync call.
     // This does *not* catch all cases, but should work for stuff running
     // in separate tabs.
     return;
   }
   nsTArray<nsRefPtr<nsDOMMutationObserver> >* suppressedObservers = nullptr;
   while (sScheduledMutationObservers) {
     nsAutoTArray<nsRefPtr<nsDOMMutationObserver>, 4>* observers =
       sScheduledMutationObservers;
     sScheduledMutationObservers = nullptr;
     for (uint32_t i = 0; i < observers->Length(); ++i) {
       sCurrentObserver = static_cast<nsDOMMutationObserver*>((*observers)[i]);
       if (!sCurrentObserver->Suppressed()) {
         sCurrentObserver->HandleMutation();
       } else {
         if (!suppressedObservers) {
           suppressedObservers = new nsTArray<nsRefPtr<nsDOMMutationObserver> >;
         }
         if (!suppressedObservers->Contains(sCurrentObserver)) {
           suppressedObservers->AppendElement(sCurrentObserver);
         }
       }
     }
     delete observers;
   }
   if (suppressedObservers) {
     for (uint32_t i = 0; i < suppressedObservers->Length(); ++i) {
       static_cast<nsDOMMutationObserver*>(suppressedObservers->ElementAt(i))->
         RescheduleForRun();
     }
     delete suppressedObservers;
     suppressedObservers = nullptr;
   }
   sCurrentObserver = nullptr;
 }
 nsDOMMutationRecord*
 nsDOMMutationObserver::CurrentRecord(nsIAtom* aType)
 {
   NS_ASSERTION(sMutationLevel > 0, "Unexpected mutation level!");
   while (mCurrentMutations.Length() < sMutationLevel) {
     mCurrentMutations.AppendElement(static_cast<nsDOMMutationRecord*>(nullptr));
   }
   uint32_t last = sMutationLevel - 1;
   if (!mCurrentMutations[last]) {
     nsRefPtr<nsDOMMutationRecord> r = new nsDOMMutationRecord(aType, GetParentObject());
     mCurrentMutations[last] = r;
     AppendMutationRecord(r.forget());
     ScheduleForRun();
   }
   NS_ASSERTION(mCurrentMutations[last]->mType == aType,
                "Unexpected MutationRecord type!");
   return mCurrentMutations[last];
 }
 nsDOMMutationObserver::~nsDOMMutationObserver()
 {
   for (int32_t i = 0; i < mReceivers.Count(); ++i) {
     mReceivers[i]->RemoveClones();
   }
 }
 void
 nsDOMMutationObserver::EnterMutationHandling()
 {
   ++sMutationLevel;
 }
 // Leave the current mutation level (there can be several levels if in case
 // of nested calls to the nsIMutationObserver methods).
 // The most recent mutation record is removed from mCurrentMutations, so
 // that is doesn't get modified anymore by receivers.
 void
 nsDOMMutationObserver::LeaveMutationHandling()
 {
   if (sCurrentlyHandlingObservers &&
       sCurrentlyHandlingObservers->Length() == sMutationLevel) {
     nsTArray<nsRefPtr<nsDOMMutationObserver> >& obs =
       sCurrentlyHandlingObservers->ElementAt(sMutationLevel - 1);
     for (uint32_t i = 0; i < obs.Length(); ++i) {
       nsDOMMutationObserver* o =
         static_cast<nsDOMMutationObserver*>(obs[i]);
       if (o->mCurrentMutations.Length() == sMutationLevel) {
         // It is already in pending mutations.
         o->mCurrentMutations.RemoveElementAt(sMutationLevel - 1);
       }
     }
     sCurrentlyHandlingObservers->RemoveElementAt(sMutationLevel - 1);
   }
   --sMutationLevel;
 }
 void
 nsDOMMutationObserver::AddCurrentlyHandlingObserver(nsDOMMutationObserver* aObserver)
 {
   NS_ASSERTION(sMutationLevel > 0, "Unexpected mutation level!");
   if (!sCurrentlyHandlingObservers) {
     sCurrentlyHandlingObservers =
       new nsAutoTArray<nsAutoTArray<nsRefPtr<nsDOMMutationObserver>, 4>, 4>;
   }
   while (sCurrentlyHandlingObservers->Length() < sMutationLevel) {
     sCurrentlyHandlingObservers->InsertElementAt(
       sCurrentlyHandlingObservers->Length());
   }
   uint32_t last = sMutationLevel - 1;
   if (!sCurrentlyHandlingObservers->ElementAt(last).Contains(aObserver)) {
     sCurrentlyHandlingObservers->ElementAt(last).AppendElement(aObserver);
   }
 }
 void
 nsDOMMutationObserver::Shutdown()
 {
   delete sCurrentlyHandlingObservers;
   sCurrentlyHandlingObservers = nullptr;
   delete sScheduledMutationObservers;
   sScheduledMutationObservers = nullptr;
 }
 nsAutoMutationBatch*
 nsAutoMutationBatch::sCurrentBatch = nullptr;
 void
 nsAutoMutationBatch::Done()
 {
   if (sCurrentBatch != this) {
     return;
   }
   sCurrentBatch = mPreviousBatch;
   if (mObservers.IsEmpty()) {
     nsDOMMutationObserver::LeaveMutationHandling();
     // Nothing to do.
     return;
   }
   uint32_t len = mObservers.Length();
   for (uint32_t i = 0; i < len; ++i) {
     nsDOMMutationObserver* ob = mObservers[i].mObserver;
     bool wantsChildList = mObservers[i].mWantsChildList;
     nsRefPtr<nsSimpleContentList> removedList;
     if (wantsChildList) {
       removedList = new nsSimpleContentList(mBatchTarget);
     }
     nsTArray<nsMutationReceiver*> allObservers;
     ob->GetAllSubtreeObserversFor(mBatchTarget, allObservers);
     int32_t j = mFromFirstToLast ? 0 : mRemovedNodes.Length() - 1;
     int32_t end = mFromFirstToLast ? mRemovedNodes.Length() : -1;
     for (; j != end; mFromFirstToLast ? ++j : --j) {
       nsCOMPtr<nsIContent> removed = mRemovedNodes[j];
       if (removedList) {
         removedList->AppendElement(removed);
       }
       if (allObservers.Length()) {
         nsCOMArray<nsMutationReceiver>* transientReceivers = nullptr;
         ob->mTransientReceivers.Get(removed, &transientReceivers);
         if (!transientReceivers) {
           transientReceivers = new nsCOMArray<nsMutationReceiver>();
           ob->mTransientReceivers.Put(removed, transientReceivers);
         }
         for (uint32_t k = 0; k < allObservers.Length(); ++k) {
           nsMutationReceiver* r = allObservers[k];
           nsMutationReceiver* orig = r->GetParent() ? r->GetParent() : r;
           if (ob->GetReceiverFor(removed, false) != orig) {
             // Make sure the elements which are removed from the
             // subtree are kept in the same observation set.
             transientReceivers->AppendObject(new nsMutationReceiver(removed, orig));
           }
         }
       }
     }
     if (wantsChildList && (mRemovedNodes.Length() || mAddedNodes.Length())) {
       nsRefPtr<nsSimpleContentList> addedList =
         new nsSimpleContentList(mBatchTarget);
       for (uint32_t i = 0; i < mAddedNodes.Length(); ++i) {
         addedList->AppendElement(mAddedNodes[i]);
       }
       nsRefPtr<nsDOMMutationRecord> m =
         new nsDOMMutationRecord(nsGkAtoms::childList,
                                 ob->GetParentObject());
       m->mTarget = mBatchTarget;
       m->mRemovedNodes = removedList;
       m->mAddedNodes = addedList;
       m->mPreviousSibling = mPrevSibling;
       m->mNextSibling = mNextSibling;
       ob->AppendMutationRecord(m.forget());
     }
     // Always schedule the observer so that transient receivers are
     // removed correctly.
     ob->ScheduleForRun();
   }
   nsDOMMutationObserver::LeaveMutationHandling();
 }

The Tor Browser / annotate

content/base/src/nsDOMMutationObserver.cpp@deefc01c0e14 (annotated)

content/base/src/nsDOMMutationObserver.cpp