/*
 * 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 StructureChain_h
#define StructureChain_h

#include "JSCell.h"
#include "JSObject.h"
#include "Structure.h"

#include <wtf/OwnArrayPtr.h>
#include <wtf/PassRefPtr.h>
#include <wtf/RefCounted.h>
#include <wtf/RefPtr.h>

namespace JSC {

class LLIntOffsetsExtractor;
class Structure;

class StructureChain : public JSCell {
	friend class JIT;

public:
	typedef JSCell Base;
	static const unsigned StructureFlags = Base::StructureFlags | StructureIsImmortal;

	static StructureChain* create(JSGlobalData& vm, Structure* head)
	{
		StructureChain* chain = new (NotNull, allocateCell<StructureChain>(vm.heap)) StructureChain(vm, vm.structureChainStructure.get());
		chain->finishCreation(vm, head);
		return chain;
	}
	WriteBarrier<Structure>* head() { return m_vector.get(); }
	static void visitChildren(JSCell*, SlotVisitor&);

	static Structure* createStructure(JSGlobalData& vm, JSGlobalObject* globalObject, JSValue prototype)
	{
		return Structure::create(vm, globalObject, prototype, TypeInfo(CellType, StructureFlags), info());
	}

	DECLARE_INFO;

	static const bool needsDestruction = true;
	static void destroy(JSCell*);

protected:
	void finishCreation(JSGlobalData& vm, Structure* head)
	{
		Base::finishCreation(vm);
		size_t size = 0;
		for (Structure* current = head; current; current = current->storedPrototype().isNull() ? 0 : asObject(current->storedPrototype())->structure())
			++size;

		m_vector = adoptArrayPtr(new WriteBarrier<Structure>[size + 1]);

		size_t i = 0;
		for (Structure* current = head; current; current = current->storedPrototype().isNull() ? 0 : asObject(current->storedPrototype())->structure())
			m_vector[i++].set(vm, this, current);
	}

private:
	friend class LLIntOffsetsExtractor;

	StructureChain(JSGlobalData&, Structure*);
	OwnArrayPtr<WriteBarrier<Structure> > m_vector;
};

} // namespace JSC

#endif // StructureChain_h
