JSPropertyNameIterator.cpp [plain text]
#include "config.h"
#include "JSPropertyNameIterator.h"
#include "JSGlobalObject.h"
namespace JSC {
const ClassInfo JSPropertyNameIterator::s_info = { "JSPropertyNameIterator", 0, 0, 0, CREATE_METHOD_TABLE(JSPropertyNameIterator) };
inline JSPropertyNameIterator::JSPropertyNameIterator(ExecState* exec, PropertyNameArrayData* propertyNameArrayData, size_t numCacheableSlots)
: JSCell(exec->vm(), exec->vm().propertyNameIteratorStructure.get())
, m_numCacheableSlots(numCacheableSlots)
, m_jsStringsSize(propertyNameArrayData->propertyNameVector().size())
, m_jsStrings(adoptArrayPtr(new WriteBarrier<Unknown>[m_jsStringsSize]))
{
}
JSPropertyNameIterator* JSPropertyNameIterator::create(ExecState* exec, JSObject* o)
{
ASSERT(!o->structure()->enumerationCache() ||
o->structure()->enumerationCache()->cachedStructure() != o->structure() ||
o->structure()->enumerationCache()->cachedPrototypeChain() != o->structure()->prototypeChain(exec));
PropertyNameArray propertyNames(exec);
o->methodTable()->getPropertyNames(o, exec, propertyNames, ExcludeDontEnumProperties);
size_t numCacheableSlots = 0;
if (!o->structure()->hasNonEnumerableProperties() && !o->structure()->hasGetterSetterProperties()
&& !o->structure()->isUncacheableDictionary() && !o->structure()->typeInfo().overridesGetPropertyNames())
numCacheableSlots = propertyNames.numCacheableSlots();
JSPropertyNameIterator* jsPropertyNameIterator = new (NotNull, allocateCell<JSPropertyNameIterator>(*exec->heap())) JSPropertyNameIterator(exec, propertyNames.data(), numCacheableSlots);
jsPropertyNameIterator->finishCreation(exec, propertyNames.data(), o);
if (o->structure()->isDictionary())
return jsPropertyNameIterator;
if (o->structure()->typeInfo().overridesGetPropertyNames())
return jsPropertyNameIterator;
if (hasIndexingHeader(o->structure()->indexingType()))
return jsPropertyNameIterator;
size_t count = normalizePrototypeChain(exec, o);
StructureChain* structureChain = o->structure()->prototypeChain(exec);
WriteBarrier<Structure>* structure = structureChain->head();
for (size_t i = 0; i < count; ++i) {
if (structure[i]->typeInfo().overridesGetPropertyNames())
return jsPropertyNameIterator;
}
jsPropertyNameIterator->setCachedPrototypeChain(exec->vm(), structureChain);
jsPropertyNameIterator->setCachedStructure(exec->vm(), o->structure());
o->structure()->setEnumerationCache(exec->vm(), jsPropertyNameIterator);
return jsPropertyNameIterator;
}
void JSPropertyNameIterator::destroy(JSCell* cell)
{
static_cast<JSPropertyNameIterator*>(cell)->JSPropertyNameIterator::~JSPropertyNameIterator();
}
JSValue JSPropertyNameIterator::get(ExecState* exec, JSObject* base, size_t i)
{
JSValue identifier = m_jsStrings[i].get();
if (m_cachedStructure.get() == base->structure() && m_cachedPrototypeChain.get() == base->structure()->prototypeChain(exec))
return identifier;
if (!base->hasProperty(exec, Identifier(exec, asString(identifier)->value(exec))))
return JSValue();
return identifier;
}
void JSPropertyNameIterator::visitChildren(JSCell* cell, SlotVisitor& visitor)
{
JSPropertyNameIterator* thisObject = jsCast<JSPropertyNameIterator*>(cell);
ASSERT_GC_OBJECT_INHERITS(thisObject, &s_info);
ASSERT(thisObject->structure()->typeInfo().overridesVisitChildren());
visitor.appendValues(thisObject->m_jsStrings.get(), thisObject->m_jsStringsSize);
visitor.append(&thisObject->m_cachedPrototypeChain);
}
}