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
34namespace JSC {
35
36ASSERT_CLASS_FITS_IN_CELL(JSPropertyNameIterator);
37
38const ClassInfo JSPropertyNameIterator::s_info = { "JSPropertyNameIterator", 0, 0, 0 };
39
40inline 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
51JSPropertyNameIterator* 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
87JSValue 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
98void 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