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/*
* Copyright (C) 2005, 2007, 2008 Apple Inc. All rights reserved.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public License
* along with this library; see the file COPYING.LIB. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
*
*/
#ifndef PropertySlot_h
#define PropertySlot_h
#include "Identifier.h"
#include "JSValue.h"
#include "Register.h"
#include <wtf/Assertions.h>
#include <wtf/NotFound.h>
namespace JSC {
class ExecState;
class JSObject;
#define JSC_VALUE_MARKER 0
#define INDEX_GETTER_MARKER reinterpret_cast<GetValueFunc>(2)
#define GETTER_FUNCTION_MARKER reinterpret_cast<GetValueFunc>(3)
class PropertySlot {
public:
enum CachedPropertyType {
Uncacheable,
Getter,
Custom,
Value
};
PropertySlot()
: m_cachedPropertyType(Uncacheable)
{
clearBase();
clearOffset();
clearValue();
}
explicit PropertySlot(const JSValue base)
: m_slotBase(base)
, m_cachedPropertyType(Uncacheable)
{
clearOffset();
clearValue();
}
typedef JSValue (*GetValueFunc)(ExecState*, JSValue slotBase, const Identifier&);
typedef JSValue (*GetIndexValueFunc)(ExecState*, JSValue slotBase, unsigned);
JSValue getValue(ExecState* exec, const Identifier& propertyName) const
{
if (m_getValue == JSC_VALUE_MARKER)
return m_value;
if (m_getValue == INDEX_GETTER_MARKER)
return m_getIndexValue(exec, slotBase(), index());
if (m_getValue == GETTER_FUNCTION_MARKER)
return functionGetter(exec);
return m_getValue(exec, slotBase(), propertyName);
}
JSValue getValue(ExecState* exec, unsigned propertyName) const
{
if (m_getValue == JSC_VALUE_MARKER)
return m_value;
if (m_getValue == INDEX_GETTER_MARKER)
return m_getIndexValue(exec, m_slotBase, m_data.index);
if (m_getValue == GETTER_FUNCTION_MARKER)
return functionGetter(exec);
return m_getValue(exec, slotBase(), Identifier::from(exec, propertyName));
}
CachedPropertyType cachedPropertyType() const { return m_cachedPropertyType; }
bool isCacheable() const { return m_cachedPropertyType != Uncacheable; }
bool isCacheableValue() const { return m_cachedPropertyType == Value; }
size_t cachedOffset() const
{
ASSERT(isCacheable());
return m_offset;
}
void setValue(JSValue slotBase, JSValue value)
{
ASSERT(value);
clearOffset();
m_getValue = JSC_VALUE_MARKER;
m_slotBase = slotBase;
m_value = value;
}
void setValue(JSValue slotBase, JSValue value, size_t offset)
{
ASSERT(value);
m_getValue = JSC_VALUE_MARKER;
m_slotBase = slotBase;
m_value = value;
m_offset = offset;
m_cachedPropertyType = Value;
}
void setValue(JSValue value)
{
ASSERT(value);
clearBase();
clearOffset();
m_getValue = JSC_VALUE_MARKER;
m_value = value;
}
void setRegisterSlot(Register* registerSlot)
{
ASSERT(registerSlot);
clearBase();
clearOffset();
m_getValue = JSC_VALUE_MARKER;
m_value = registerSlot->jsValue();
}
void setCustom(JSValue slotBase, GetValueFunc getValue)
{
ASSERT(slotBase);
ASSERT(getValue);
m_getValue = getValue;
m_getIndexValue = 0;
m_slotBase = slotBase;
}
void setCacheableCustom(JSValue slotBase, GetValueFunc getValue)
{
ASSERT(slotBase);
ASSERT(getValue);
m_getValue = getValue;
m_getIndexValue = 0;
m_slotBase = slotBase;
m_cachedPropertyType = Custom;
}
void setCustomIndex(JSValue slotBase, unsigned index, GetIndexValueFunc getIndexValue)
{
ASSERT(slotBase);
ASSERT(getIndexValue);
m_getValue = INDEX_GETTER_MARKER;
m_getIndexValue = getIndexValue;
m_slotBase = slotBase;
m_data.index = index;
}
void setGetterSlot(JSObject* getterFunc)
{
ASSERT(getterFunc);
m_thisValue = m_slotBase;
m_getValue = GETTER_FUNCTION_MARKER;
m_data.getterFunc = getterFunc;
}
void setCacheableGetterSlot(JSValue slotBase, JSObject* getterFunc, unsigned offset)
{
ASSERT(getterFunc);
m_getValue = GETTER_FUNCTION_MARKER;
m_thisValue = m_slotBase;
m_slotBase = slotBase;
m_data.getterFunc = getterFunc;
m_offset = offset;
m_cachedPropertyType = Getter;
}
void setUndefined()
{
setValue(jsUndefined());
}
JSValue slotBase() const
{
return m_slotBase;
}
void setBase(JSValue base)
{
ASSERT(m_slotBase);
ASSERT(base);
m_slotBase = base;
}
void clearBase()
{
#ifndef NDEBUG
m_slotBase = JSValue();
#endif
}
void clearValue()
{
#ifndef NDEBUG
m_value = JSValue();
#endif
}
void clearOffset()
{
// Clear offset even in release builds, in case this PropertySlot has been used before.
// (For other data members, we don't need to clear anything because reuse would meaningfully overwrite them.)
m_offset = 0;
m_cachedPropertyType = Uncacheable;
}
unsigned index() const { return m_data.index; }
JSValue thisValue() const { return m_thisValue; }
GetValueFunc customGetter() const
{
ASSERT(m_cachedPropertyType == Custom);
return m_getValue;
}
private:
JSValue functionGetter(ExecState*) const;
GetValueFunc m_getValue;
GetIndexValueFunc m_getIndexValue;
JSValue m_slotBase;
union {
JSObject* getterFunc;
unsigned index;
} m_data;
JSValue m_value;
JSValue m_thisValue;
size_t m_offset;
CachedPropertyType m_cachedPropertyType;
};
} // namespace JSC
#endif // PropertySlot_h
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