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/*
* Copyright (C) 2008 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef Structure_h
#define Structure_h
#include "Identifier.h"
#include "JSType.h"
#include "JSValue.h"
#include "PropertyMapHashTable.h"
#include "StructureTransitionTable.h"
#include "TypeInfo.h"
#include "UString.h"
#include <wtf/PassRefPtr.h>
#include <wtf/RefCounted.h>
#ifndef NDEBUG
#define DUMP_PROPERTYMAP_STATS 0
#else
#define DUMP_PROPERTYMAP_STATS 0
#endif
namespace JSC {
class PropertyNameArray;
class PropertyNameArrayData;
class StructureChain;
class Structure : public RefCounted<Structure> {
public:
enum ListedAttribute {
NonEnumerable = 1 << 1,
Prototype = 1 << 2
};
friend class JIT;
static PassRefPtr<Structure> create(JSValue prototype, const TypeInfo& typeInfo)
{
return adoptRef(new Structure(prototype, typeInfo));
}
static void startIgnoringLeaks();
static void stopIgnoringLeaks();
static void dumpStatistics();
static PassRefPtr<Structure> addPropertyTransition(Structure*, const Identifier& propertyName, unsigned attributes, JSCell* specificValue, size_t& offset);
static PassRefPtr<Structure> addPropertyTransitionToExistingStructure(Structure*, const Identifier& propertyName, unsigned attributes, JSCell* specificValue, size_t& offset);
static PassRefPtr<Structure> removePropertyTransition(Structure*, const Identifier& propertyName, size_t& offset);
static PassRefPtr<Structure> changePrototypeTransition(Structure*, JSValue prototype);
static PassRefPtr<Structure> despecifyFunctionTransition(Structure*, const Identifier&);
static PassRefPtr<Structure> getterSetterTransition(Structure*);
static PassRefPtr<Structure> toDictionaryTransition(Structure*);
static PassRefPtr<Structure> fromDictionaryTransition(Structure*);
~Structure();
void mark()
{
if (!m_prototype.marked())
m_prototype.mark();
}
// These should be used with caution.
size_t addPropertyWithoutTransition(const Identifier& propertyName, unsigned attributes, JSCell* specificValue);
size_t removePropertyWithoutTransition(const Identifier& propertyName);
void setPrototypeWithoutTransition(JSValue prototype) { m_prototype = prototype; }
bool isDictionary() const { return m_isDictionary; }
const TypeInfo& typeInfo() const { return m_typeInfo; }
JSValue storedPrototype() const { return m_prototype; }
JSValue prototypeForLookup(ExecState*) const;
StructureChain* prototypeChain(ExecState*) const;
Structure* previousID() const { return m_previous.get(); }
void growPropertyStorageCapacity();
size_t propertyStorageCapacity() const { return m_propertyStorageCapacity; }
size_t propertyStorageSize() const { return m_propertyTable ? m_propertyTable->keyCount + (m_propertyTable->deletedOffsets ? m_propertyTable->deletedOffsets->size() : 0) : m_offset + 1; }
bool isUsingInlineStorage() const;
size_t get(const Identifier& propertyName);
size_t get(const UString::Rep* rep, unsigned& attributes, JSCell*& specificValue);
size_t get(const Identifier& propertyName, unsigned& attributes, JSCell*& specificValue)
{
ASSERT(!propertyName.isNull());
return get(propertyName._ustring.rep(), attributes, specificValue);
}
void getPropertyNames(ExecState*, PropertyNameArray&, JSObject*, unsigned listedAttributes = Prototype);
bool hasGetterSetterProperties() const { return m_hasGetterSetterProperties; }
void setHasGetterSetterProperties(bool hasGetterSetterProperties) { m_hasGetterSetterProperties = hasGetterSetterProperties; }
bool isEmpty() const { return m_propertyTable ? !m_propertyTable->keyCount : m_offset == noOffset; }
JSCell* specificValue() { return m_specificValueInPrevious; }
void despecifyDictionaryFunction(const Identifier& propertyName);
private:
Structure(JSValue prototype, const TypeInfo&);
size_t put(const Identifier& propertyName, unsigned attributes, JSCell* specificValue);
size_t remove(const Identifier& propertyName);
void getNamesFromPropertyTable(PropertyNameArray&, bool includeNonEnumerable = false);
void getNamesFromClassInfoTable(ExecState*, const ClassInfo*, PropertyNameArray&, bool includeNonEnumerable = false);
void expandPropertyMapHashTable();
void rehashPropertyMapHashTable();
void rehashPropertyMapHashTable(unsigned newTableSize);
void createPropertyMapHashTable();
void createPropertyMapHashTable(unsigned newTableSize);
void insertIntoPropertyMapHashTable(const PropertyMapEntry&);
void checkConsistency();
bool despecifyFunction(const Identifier&);
PropertyMapHashTable* copyPropertyTable();
void materializePropertyMap();
void materializePropertyMapIfNecessary()
{
if (m_propertyTable || !m_previous)
return;
materializePropertyMap();
}
void clearEnumerationCache();
signed char transitionCount() const
{
// Since the number of transitions is always the same as m_offset, we keep the size of Structure down by not storing both.
return m_offset == noOffset ? 0 : m_offset + 1;
}
bool isValid(ExecState*, StructureChain* cachedPrototypeChain) const;
static const unsigned emptyEntryIndex = 0;
static const signed char s_maxTransitionLength = 64;
static const signed char noOffset = -1;
TypeInfo m_typeInfo;
JSValue m_prototype;
mutable RefPtr<StructureChain> m_cachedPrototypeChain;
RefPtr<Structure> m_previous;
RefPtr<UString::Rep> m_nameInPrevious;
union {
Structure* singleTransition;
StructureTransitionTable* table;
} m_transitions;
JSCell* m_specificValueInPrevious;
RefPtr<PropertyNameArrayData> m_cachedPropertyNameArrayData;
PropertyMapHashTable* m_propertyTable;
size_t m_propertyStorageCapacity;
signed char m_offset;
bool m_isDictionary : 1;
bool m_isPinnedPropertyTable : 1;
bool m_hasGetterSetterProperties : 1;
bool m_usingSingleTransitionSlot : 1;
unsigned m_attributesInPrevious : 7;
};
inline size_t Structure::get(const Identifier& propertyName)
{
ASSERT(!propertyName.isNull());
materializePropertyMapIfNecessary();
if (!m_propertyTable)
return WTF::notFound;
UString::Rep* rep = propertyName._ustring.rep();
unsigned i = rep->computedHash();
#if DUMP_PROPERTYMAP_STATS
++numProbes;
#endif
unsigned entryIndex = m_propertyTable->entryIndices[i & m_propertyTable->sizeMask];
if (entryIndex == emptyEntryIndex)
return WTF::notFound;
if (rep == m_propertyTable->entries()[entryIndex - 1].key)
return m_propertyTable->entries()[entryIndex - 1].offset;
#if DUMP_PROPERTYMAP_STATS
++numCollisions;
#endif
unsigned k = 1 | WTF::doubleHash(rep->computedHash());
while (1) {
i += k;
#if DUMP_PROPERTYMAP_STATS
++numRehashes;
#endif
entryIndex = m_propertyTable->entryIndices[i & m_propertyTable->sizeMask];
if (entryIndex == emptyEntryIndex)
return WTF::notFound;
if (rep == m_propertyTable->entries()[entryIndex - 1].key)
return m_propertyTable->entries()[entryIndex - 1].offset;
}
}
} // namespace JSC
#endif // Structure_h
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