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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 const ClassInfo JSPropertyNameIterator::s_info = { "JSPropertyNameIterator", 0, 0, 0 };
39 
JSPropertyNameIterator(ExecState * exec,PropertyNameArrayData * propertyNameArrayData,size_t numCacheableSlots)40 inline JSPropertyNameIterator::JSPropertyNameIterator(ExecState* exec, PropertyNameArrayData* propertyNameArrayData, size_t numCacheableSlots)
41     : JSCell(exec->globalData(), exec->globalData().propertyNameIteratorStructure.get())
42     , m_numCacheableSlots(numCacheableSlots)
43     , m_jsStringsSize(propertyNameArrayData->propertyNameVector().size())
44     , m_jsStrings(adoptArrayPtr(new WriteBarrier<Unknown>[m_jsStringsSize]))
45 {
46     PropertyNameArrayData::PropertyNameVector& propertyNameVector = propertyNameArrayData->propertyNameVector();
47     for (size_t i = 0; i < m_jsStringsSize; ++i)
48         m_jsStrings[i].set(exec->globalData(), this, jsOwnedString(exec, propertyNameVector[i].ustring()));
49 }
50 
create(ExecState * exec,JSObject * o)51 JSPropertyNameIterator* JSPropertyNameIterator::create(ExecState* exec, JSObject* o)
52 {
53     ASSERT(!o->structure()->enumerationCache() ||
54             o->structure()->enumerationCache()->cachedStructure() != o->structure() ||
55             o->structure()->enumerationCache()->cachedPrototypeChain() != o->structure()->prototypeChain(exec));
56 
57     PropertyNameArray propertyNames(exec);
58     o->getPropertyNames(exec, propertyNames);
59     size_t numCacheableSlots = 0;
60     if (!o->structure()->hasNonEnumerableProperties() && !o->structure()->hasAnonymousSlots() &&
61         !o->structure()->hasGetterSetterProperties() && !o->structure()->isUncacheableDictionary() &&
62         !o->structure()->typeInfo().overridesGetPropertyNames())
63         numCacheableSlots = o->structure()->propertyStorageSize();
64 
65     JSPropertyNameIterator* jsPropertyNameIterator = new (exec) JSPropertyNameIterator(exec, propertyNames.data(), numCacheableSlots);
66 
67     if (o->structure()->isDictionary())
68         return jsPropertyNameIterator;
69 
70     if (o->structure()->typeInfo().overridesGetPropertyNames())
71         return jsPropertyNameIterator;
72 
73     size_t count = normalizePrototypeChain(exec, o);
74     StructureChain* structureChain = o->structure()->prototypeChain(exec);
75     WriteBarrier<Structure>* structure = structureChain->head();
76     for (size_t i = 0; i < count; ++i) {
77         if (structure[i]->typeInfo().overridesGetPropertyNames())
78             return jsPropertyNameIterator;
79     }
80 
81     jsPropertyNameIterator->setCachedPrototypeChain(exec->globalData(), structureChain);
82     jsPropertyNameIterator->setCachedStructure(exec->globalData(), o->structure());
83     o->structure()->setEnumerationCache(exec->globalData(), jsPropertyNameIterator);
84     return jsPropertyNameIterator;
85 }
86 
get(ExecState * exec,JSObject * base,size_t i)87 JSValue JSPropertyNameIterator::get(ExecState* exec, JSObject* base, size_t i)
88 {
89     JSValue identifier = m_jsStrings[i].get();
90     if (m_cachedStructure.get() == base->structure() && m_cachedPrototypeChain.get() == base->structure()->prototypeChain(exec))
91         return identifier;
92 
93     if (!base->hasProperty(exec, Identifier(exec, asString(identifier)->value(exec))))
94         return JSValue();
95     return identifier;
96 }
97 
markChildren(MarkStack & markStack)98 void JSPropertyNameIterator::markChildren(MarkStack& markStack)
99 {
100     markStack.appendValues(m_jsStrings.get(), m_jsStringsSize, MayContainNullValues);
101     if (m_cachedPrototypeChain)
102         markStack.append(&m_cachedPrototypeChain);
103 }
104 
105 } // namespace JSC
106