JavaScriptCore/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 ASSERT_CLASS_FITS_IN_CELL(JSPropertyNameIterator);
  37
  38 JSPropertyNameIterator* JSPropertyNameIterator::create(ExecState* exec, JSObject* o)
  39 {
  40     ASSERT(!o->structure()->enumerationCache() ||
  41             o->structure()->enumerationCache()->cachedStructure() != o->structure() ||
  42             o->structure()->enumerationCache()->cachedPrototypeChain() != o->structure()->prototypeChain(exec));
  43
  44     PropertyNameArray propertyNames(exec);
  45     o->getPropertyNames(exec, propertyNames);
  46     size_t numCacheableSlots = 0;
  47     if (!o->structure()->hasNonEnumerableProperties() && !o->structure()->hasAnonymousSlots() &&
  48         !o->structure()->hasGetterSetterProperties() && !o->structure()->isUncacheableDictionary() &&
  49         !o->structure()->typeInfo().overridesGetPropertyNames())
  50         numCacheableSlots = o->structure()->propertyStorageSize();
  51
  52     JSPropertyNameIterator* jsPropertyNameIterator = new (exec) JSPropertyNameIterator(exec, propertyNames.data(), numCacheableSlots);
  53
  54     if (o->structure()->isDictionary())
  55         return jsPropertyNameIterator;
  56
  57     if (o->structure()->typeInfo().overridesGetPropertyNames())
  58         return jsPropertyNameIterator;
  59
  60     size_t count = normalizePrototypeChain(exec, o);
  61     StructureChain* structureChain = o->structure()->prototypeChain(exec);
  62     RefPtr<Structure>* structure = structureChain->head();
  63     for (size_t i = 0; i < count; ++i) {
  64         if (structure[i]->typeInfo().overridesGetPropertyNames())
  65             return jsPropertyNameIterator;
  66     }
  67
  68     jsPropertyNameIterator->setCachedPrototypeChain(structureChain);
  69     jsPropertyNameIterator->setCachedStructure(o->structure());
  70     o->structure()->setEnumerationCache(jsPropertyNameIterator);
  71     return jsPropertyNameIterator;
  72 }
  73
  74 JSValue JSPropertyNameIterator::get(ExecState* exec, JSObject* base, size_t i)
  75 {
  76     JSValue& identifier = m_jsStrings[i];
  77     if (m_cachedStructure == base->structure() && m_cachedPrototypeChain == base->structure()->prototypeChain(exec))
  78         return identifier;
  79
  80     if (!base->hasProperty(exec, Identifier(exec, asString(identifier)->value(exec))))
  81         return JSValue();
  82     return identifier;
  83 }
  84
  85 void JSPropertyNameIterator::markChildren(MarkStack& markStack)
  86 {
  87     markStack.appendValues(m_jsStrings.get(), m_jsStringsSize, MayContainNullValues);
  88 }
  89
  90 } // namespace JSC