[apple/javascriptcore.git] / runtime / StructureIDTable.h

/*
 * Copyright (C) 2013 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 INC. AND ITS CONTRIBUTORS ``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 INC. OR ITS 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 StructureIDTable_h
#define StructureIDTable_h

#include "UnusedPointer.h"
#include <wtf/OwnPtr.h>
#include <wtf/Vector.h>

namespace JSC {

class Structure;

#if USE(JSVALUE64)
typedef uint32_t StructureID;
#else
typedef Structure* StructureID;
#endif

class StructureIDTable {
    friend class LLIntOffsetsExtractor;
public:
    StructureIDTable();

    void** base() { return reinterpret_cast<void**>(&m_table); }

    Structure* get(StructureID);
    void deallocateID(Structure*, StructureID);
    StructureID allocateID(Structure*);

    void flushOldTables();

private:
    void resize(size_t newCapacity);

    union StructureOrOffset {
        WTF_MAKE_FAST_ALLOCATED;
    public:
        Structure* structure;
        StructureID offset;
    };

    StructureOrOffset* table() const { return m_table.get(); }
    
    static const size_t s_initialSize = 256;

    Vector<OwnPtr<StructureOrOffset>> m_oldTables;

    uint32_t m_firstFreeOffset;
    OwnPtr<StructureOrOffset> m_table;

    size_t m_size;
    size_t m_capacity;

#if USE(JSVALUE64)
    static const StructureID s_unusedID = unusedPointer;
#endif
};

inline Structure* StructureIDTable::get(StructureID structureID)
{
#if USE(JSVALUE64)
    return table()[structureID].structure;
#else
    return structureID;
#endif
}

} // namespace JSC

#endif // StructureIDTable_h
Commit	Line	Data
81345200 A	1	/*
	2	* Copyright (C) 2013 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	* 1. Redistributions of source code must retain the above copyright
	8	* notice, this list of conditions and the following disclaimer.
	9	* 2. Redistributions in binary form must reproduce the above copyright
	10	* notice, this list of conditions and the following disclaimer in the
	11	* documentation and/or other materials provided with the distribution.
	12	*
	13	* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
	14	* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
	15	* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
	16	* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
	17	* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
	18	* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
	19	* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
	20	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
	21	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
	22	* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
	23	* THE POSSIBILITY OF SUCH DAMAGE.
	24	*/
	25
	26	#ifndef StructureIDTable_h
	27	#define StructureIDTable_h
	28
	29	#include "UnusedPointer.h"
	30	#include <wtf/OwnPtr.h>
	31	#include <wtf/Vector.h>
	32
	33	namespace JSC {
	34
	35	class Structure;
	36
	37	#if USE(JSVALUE64)
	38	typedef uint32_t StructureID;
	39	#else
	40	typedef Structure* StructureID;
	41	#endif
	42
	43	class StructureIDTable {
	44	friend class LLIntOffsetsExtractor;
	45	public:
	46	StructureIDTable();
	47
	48	void base() { return reinterpret_cast<void>(&m_table); }
	49
	50	Structure* get(StructureID);
	51	void deallocateID(Structure*, StructureID);
	52	StructureID allocateID(Structure*);
	53
	54	void flushOldTables();
	55
	56	private:
	57	void resize(size_t newCapacity);
	58
	59	union StructureOrOffset {
	60	WTF_MAKE_FAST_ALLOCATED;
	61	public:
	62	Structure* structure;
	63	StructureID offset;
	64	};
65
66	StructureOrOffset* table() const { return m_table.get(); }
67
68	static const size_t s_initialSize = 256;
69
70	Vector<OwnPtr<StructureOrOffset>> m_oldTables;
71
72	uint32_t m_firstFreeOffset;
73	OwnPtr<StructureOrOffset> m_table;
74
75	size_t m_size;
76	size_t m_capacity;
77
78	#if USE(JSVALUE64)
79	static const StructureID s_unusedID = unusedPointer;
80	#endif
81	};
82
83	inline Structure* StructureIDTable::get(StructureID structureID)
84	{
85	#if USE(JSVALUE64)
86	return table()[structureID].structure;
87	#else
88	return structureID;
89	#endif
90	}
91
92	} // namespace JSC
93
94	#endif // StructureIDTable_h