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 inline JSPropertyNameIterator::JSPropertyNameIterator(ExecState* exec, PropertyNameArrayData* propertyNameArrayData, size_t numCacheableSlots)

    39     : JSCell(exec->globalData().propertyNameIteratorStructure.get())

    40     , m_cachedStructure(0)

    41     , m_numCacheableSlots(numCacheableSlots)

    42     , m_jsStringsSize(propertyNameArrayData->propertyNameVector().size())

    43     , m_jsStrings(new JSValue[m_jsStringsSize])

    44 {

    45     PropertyNameArrayData::PropertyNameVector& propertyNameVector = propertyNameArrayData->propertyNameVector();

    46     for (size_t i = 0; i < m_jsStringsSize; ++i)

    47         m_jsStrings[i] = jsOwnedString(exec, propertyNameVector[i].ustring());

    48 }

    49 

    50 JSPropertyNameIterator::~JSPropertyNameIterator()

    51 {

    52     if (m_cachedStructure)

    53         m_cachedStructure->clearEnumerationCache(this);

    54 }

    55 

    56 JSPropertyNameIterator* JSPropertyNameIterator::create(ExecState* exec, JSObject* o)

    57 {

    58     ASSERT(!o->structure()->enumerationCache() ||

    59             o->structure()->enumerationCache()->cachedStructure() != o->structure() ||

    60             o->structure()->enumerationCache()->cachedPrototypeChain() != o->structure()->prototypeChain(exec));

    61 

    62     PropertyNameArray propertyNames(exec);

    63     o->getPropertyNames(exec, propertyNames);

    64     size_t numCacheableSlots = 0;

    65     if (!o->structure()->hasNonEnumerableProperties() && !o->structure()->hasAnonymousSlots() &&

    66         !o->structure()->hasGetterSetterProperties() && !o->structure()->isUncacheableDictionary() &&

    67         !o->structure()->typeInfo().overridesGetPropertyNames())

    68         numCacheableSlots = o->structure()->propertyStorageSize();

    69 

    70     JSPropertyNameIterator* jsPropertyNameIterator = new (exec) JSPropertyNameIterator(exec, propertyNames.data(), numCacheableSlots);

    71 

    72     if (o->structure()->isDictionary())

    73         return jsPropertyNameIterator;

    74 

    75     if (o->structure()->typeInfo().overridesGetPropertyNames())

    76         return jsPropertyNameIterator;

    77     

    78     size_t count = normalizePrototypeChain(exec, o);

    79     StructureChain* structureChain = o->structure()->prototypeChain(exec);

    80     RefPtr<Structure>* structure = structureChain->head();

    81     for (size_t i = 0; i < count; ++i) {

    82         if (structure[i]->typeInfo().overridesGetPropertyNames())

    83             return jsPropertyNameIterator;

    84     }

    85 

    86     jsPropertyNameIterator->setCachedPrototypeChain(structureChain);

    87     jsPropertyNameIterator->setCachedStructure(o->structure());

    88     o->structure()->setEnumerationCache(jsPropertyNameIterator);

    89     return jsPropertyNameIterator;

    90 }

    91 

    92 JSValue JSPropertyNameIterator::get(ExecState* exec, JSObject* base, size_t i)

    93 {

    94     JSValue& identifier = m_jsStrings[i];

    95     if (m_cachedStructure == base->structure() && m_cachedPrototypeChain == base->structure()->prototypeChain(exec))

    96         return identifier;

    97 

    98     if (!base->hasProperty(exec, Identifier(exec, asString(identifier)->value(exec))))

    99         return JSValue();

   100     return identifier;

   101 }

   102 

   103 void JSPropertyNameIterator::markChildren(MarkStack& markStack)

   104 {

   105     markStack.appendValues(m_jsStrings.get(), m_jsStringsSize, MayContainNullValues);

   106 }

   107 

   108 } // namespace JSC