Structure* Structure::nonPropertyTransition(VM& vm, Structure* structure, NonPropertyTransition transitionKind)
{
unsigned attributes = toAttributes(transitionKind);
IndexingType indexingType = newIndexingType(structure->indexingTypeIncludingHistory(), transitionKind);
if (JSGlobalObject* globalObject = structure->m_globalObject.get()) {
if (globalObject->isOriginalArrayStructure(structure)) {
Structure* result = globalObject->originalArrayStructureForIndexingType(indexingType);
if (result->indexingTypeIncludingHistory() == indexingType) {
structure->didTransitionFromThisStructure();
return result;
}
}
}
Structure* existingTransition;
if (!structure->isDictionary() && (existingTransition = structure->m_transitionTable.get(0, attributes))) {
ASSERT(existingTransition->attributesInPrevious() == attributes);
ASSERT(existingTransition->indexingTypeIncludingHistory() == indexingType);
return existingTransition;
}
Structure* transition = create(vm, structure);
transition->setAttributesInPrevious(attributes);
transition->m_blob.setIndexingType(indexingType);
transition->propertyTable().set(vm, transition, structure->takePropertyTableOrCloneIfPinned(vm));
transition->m_offset = structure->m_offset;
checkOffset(transition->m_offset, transition->inlineCapacity());
if (structure->isDictionary())
transition->pin();
else {
ConcurrentJITLocker locker(structure->m_lock);
structure->m_transitionTable.add(vm, transition);
}
transition->checkOffsetConsistency();
return transition;
}
Structure* Structure::addNewPropertyTransition(VM& vm, Structure* structure, PropertyName propertyName, unsigned attributes, PropertyOffset& offset, PutPropertySlot::Context context, DeferredStructureTransitionWatchpointFire* deferred)
{
ASSERT(!structure->isDictionary());
ASSERT(structure->isObject());
ASSERT(!Structure::addPropertyTransitionToExistingStructure(structure, propertyName, attributes, offset));
int maxTransitionLength;
if (context == PutPropertySlot::PutById)
maxTransitionLength = s_maxTransitionLengthForNonEvalPutById;
else
maxTransitionLength = s_maxTransitionLength;
if (structure->transitionCount() > maxTransitionLength) {
Structure* transition = toCacheableDictionaryTransition(vm, structure, deferred);
ASSERT(structure != transition);
offset = transition->add(vm, propertyName, attributes);
return transition;
}
Structure* transition = create(vm, structure, deferred);
transition->m_cachedPrototypeChain.setMayBeNull(vm, transition, structure->m_cachedPrototypeChain.get());
transition->m_nameInPrevious = propertyName.uid();
transition->setAttributesInPrevious(attributes);
transition->propertyTable().set(vm, transition, structure->takePropertyTableOrCloneIfPinned(vm));
transition->m_offset = structure->m_offset;
transition->m_inferredTypeTable.setMayBeNull(vm, transition, structure->m_inferredTypeTable.get());
offset = transition->add(vm, propertyName, attributes);
checkOffset(transition->m_offset, transition->inlineCapacity());
{
ConcurrentJITLocker locker(structure->m_lock);
structure->m_transitionTable.add(vm, transition);
}
transition->checkOffsetConsistency();
structure->checkOffsetConsistency();
return transition;
}
Structure* Structure::nonPropertyTransition(VM& vm, Structure* structure, NonPropertyTransition transitionKind)
{
unsigned attributes = toAttributes(transitionKind);
IndexingType indexingType = newIndexingType(structure->indexingTypeIncludingHistory(), transitionKind);
if (changesIndexingType(transitionKind)) {
if (JSGlobalObject* globalObject = structure->m_globalObject.get()) {
if (globalObject->isOriginalArrayStructure(structure)) {
Structure* result = globalObject->originalArrayStructureForIndexingType(indexingType);
if (result->indexingTypeIncludingHistory() == indexingType) {
structure->didTransitionFromThisStructure();
return result;
}
}
}
}
Structure* existingTransition;
if (!structure->isDictionary() && (existingTransition = structure->m_transitionTable.get(0, attributes))) {
ASSERT(existingTransition->attributesInPrevious() == attributes);
ASSERT(existingTransition->indexingTypeIncludingHistory() == indexingType);
return existingTransition;
}
DeferGC deferGC(vm.heap);
Structure* transition = create(vm, structure);
transition->setAttributesInPrevious(attributes);
transition->m_blob.setIndexingType(indexingType);
if (preventsExtensions(transitionKind))
transition->setDidPreventExtensions(true);
if (setsDontDeleteOnAllProperties(transitionKind)
|| setsReadOnlyOnNonAccessorProperties(transitionKind)) {
// We pin the property table on transitions that do wholesale editing of the property
// table, since our logic for walking the property transition chain to rematerialize the
// table doesn't know how to take into account such wholesale edits.
structure->materializePropertyMapIfNecessary(vm, deferGC);
transition->propertyTable().set(vm, transition, structure->copyPropertyTableForPinning(vm));
transition->m_offset = structure->m_offset;
transition->pinForCaching();
if (transition->propertyTable()) {
for (auto& entry : *transition->propertyTable().get()) {
if (setsDontDeleteOnAllProperties(transitionKind))
entry.attributes |= DontDelete;
if (setsReadOnlyOnNonAccessorProperties(transitionKind) && !(entry.attributes & Accessor))
entry.attributes |= ReadOnly;
}
}
} else {
transition->propertyTable().set(vm, transition, structure->takePropertyTableOrCloneIfPinned(vm));
transition->m_offset = structure->m_offset;
checkOffset(transition->m_offset, transition->inlineCapacity());
}
if (setsReadOnlyOnNonAccessorProperties(transitionKind)
&& transition->propertyTable()
&& !transition->propertyTable()->isEmpty())
transition->setHasReadOnlyOrGetterSetterPropertiesExcludingProto(true);
if (structure->isDictionary())
transition->pin();
else {
ConcurrentJITLocker locker(structure->m_lock);
structure->m_transitionTable.add(vm, transition);
}
transition->checkOffsetConsistency();
return transition;
}