runtime/JSPropertyNameIterator.cpp

   1 /*
   2  * Copyright (C) 2008, 2009 Apple Inc. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  *
   8  * 1.  Redistributions of source code must retain the above copyright
   9  *     notice, this list of conditions and the following disclaimer.
  10  * 2.  Redistributions in binary form must reproduce the above copyright
  11  *     notice, this list of conditions and the following disclaimer in the
  12  *     documentation and/or other materials provided with the distribution.
  13  * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
  14  *     its contributors may be used to endorse or promote products derived
  15  *     from this software without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
  18  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  19  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  20  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
  21  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  22  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  23  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  24  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 #include "config.h"
  30 #include "JSPropertyNameIterator.h"
  31
  32 #include "JSGlobalObject.h"
  33
  34 namespace JSC {
  35
  36 const ClassInfo JSPropertyNameIterator::s_info = { "JSPropertyNameIterator", 0, 0, 0, CREATE_METHOD_TABLE(JSPropertyNameIterator) };
  37
  38 inline JSPropertyNameIterator::JSPropertyNameIterator(ExecState* exec, PropertyNameArrayData* propertyNameArrayData, size_t numCacheableSlots)
  39     : JSCell(exec->vm(), exec->vm().propertyNameIteratorStructure.get())
  40     , m_numCacheableSlots(numCacheableSlots)
  41     , m_jsStringsSize(propertyNameArrayData->propertyNameVector().size())
  42     , m_jsStrings(adoptArrayPtr(new WriteBarrier<Unknown>[m_jsStringsSize]))
  43 {
  44 }
  45
  46 JSPropertyNameIterator* JSPropertyNameIterator::create(ExecState* exec, JSObject* o)
  47 {
  48     ASSERT(!o->structure()->enumerationCache() ||
  49             o->structure()->enumerationCache()->cachedStructure() != o->structure() ||
  50             o->structure()->enumerationCache()->cachedPrototypeChain() != o->structure()->prototypeChain(exec));
  51
  52     PropertyNameArray propertyNames(exec);
  53     o->methodTable()->getPropertyNames(o, exec, propertyNames, ExcludeDontEnumProperties);
  54     size_t numCacheableSlots = 0;
  55     if (!o->structure()->hasNonEnumerableProperties() && !o->structure()->hasGetterSetterProperties()
  56         && !o->structure()->isUncacheableDictionary() && !o->structure()->typeInfo().overridesGetPropertyNames())
  57         numCacheableSlots = propertyNames.numCacheableSlots();
  58
  59     JSPropertyNameIterator* jsPropertyNameIterator = new (NotNull, allocateCell<JSPropertyNameIterator>(*exec->heap())) JSPropertyNameIterator(exec, propertyNames.data(), numCacheableSlots);
  60     jsPropertyNameIterator->finishCreation(exec, propertyNames.data(), o);
  61
  62     if (o->structure()->isDictionary())
  63         return jsPropertyNameIterator;
  64
  65     if (o->structure()->typeInfo().overridesGetPropertyNames())
  66         return jsPropertyNameIterator;
  67
  68     if (hasIndexingHeader(o->structure()->indexingType()))
  69         return jsPropertyNameIterator;
  70
  71     size_t count = normalizePrototypeChain(exec, o);
  72     StructureChain* structureChain = o->structure()->prototypeChain(exec);
  73     WriteBarrier<Structure>* structure = structureChain->head();
  74     for (size_t i = 0; i < count; ++i) {
  75         if (structure[i]->typeInfo().overridesGetPropertyNames())
  76             return jsPropertyNameIterator;
  77     }
  78
  79     jsPropertyNameIterator->setCachedPrototypeChain(exec->vm(), structureChain);
  80     jsPropertyNameIterator->setCachedStructure(exec->vm(), o->structure());
  81     o->structure()->setEnumerationCache(exec->vm(), jsPropertyNameIterator);
  82     return jsPropertyNameIterator;
  83 }
  84
  85 void JSPropertyNameIterator::destroy(JSCell* cell)
  86 {
  87     static_cast<JSPropertyNameIterator*>(cell)->JSPropertyNameIterator::~JSPropertyNameIterator();
  88 }
  89
  90 JSValue JSPropertyNameIterator::get(ExecState* exec, JSObject* base, size_t i)
  91 {
  92     JSValue identifier = m_jsStrings[i].get();
  93     if (m_cachedStructure.get() == base->structure() && m_cachedPrototypeChain.get() == base->structure()->prototypeChain(exec))
  94         return identifier;
  95
  96     if (!base->hasProperty(exec, Identifier(exec, asString(identifier)->value(exec))))
  97         return JSValue();
  98     return identifier;
  99 }
 100
 101 void JSPropertyNameIterator::visitChildren(JSCell* cell, SlotVisitor& visitor)
 102 {
 103     JSPropertyNameIterator* thisObject = jsCast<JSPropertyNameIterator*>(cell);
 104     ASSERT_GC_OBJECT_INHERITS(thisObject, &s_info);
 105     ASSERT(thisObject->structure()->typeInfo().overridesVisitChildren());
 106     visitor.appendValues(thisObject->m_jsStrings.get(), thisObject->m_jsStringsSize);
 107     visitor.append(&thisObject->m_cachedPrototypeChain);
 108 }
 109
 110 } // namespace JSC