runtime/StructureChain.h

   1 /*
   2  * Copyright (C) 2008 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 COMPUTER, INC. ``AS IS'' AND ANY
  14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
  17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #ifndef StructureChain_h
  27 #define StructureChain_h
  28
  29 #include "JSCell.h"
  30 #include "JSObject.h"
  31 #include "Structure.h"
  32
  33 #include <wtf/OwnArrayPtr.h>
  34 #include <wtf/PassRefPtr.h>
  35 #include <wtf/RefCounted.h>
  36 #include <wtf/RefPtr.h>
  37
  38 namespace JSC {
  39
  40     class LLIntOffsetsExtractor;
  41     class Structure;
  42
  43     class StructureChain : public JSCell {
  44         friend class JIT;
  45
  46     public:
  47         typedef JSCell Base;
  48
  49         static StructureChain* create(JSGlobalData& globalData, Structure* head)
  50         {
  51             StructureChain* chain = new (NotNull, allocateCell<StructureChain>(globalData.heap)) StructureChain(globalData, globalData.structureChainStructure.get());
  52             chain->finishCreation(globalData, head);
  53             return chain;
  54         }
  55         WriteBarrier<Structure>* head() { return m_vector.get(); }
  56         static void visitChildren(JSCell*, SlotVisitor&);
  57
  58         static Structure* createStructure(JSGlobalData& globalData, JSGlobalObject* globalObject, JSValue prototype) { return Structure::create(globalData, globalObject, prototype, TypeInfo(CompoundType, OverridesVisitChildren), &s_info); }
  59
  60         static ClassInfo s_info;
  61
  62     protected:
  63         void finishCreation(JSGlobalData& globalData, Structure* head)
  64         {
  65             Base::finishCreation(globalData);
  66             size_t size = 0;
  67             for (Structure* current = head; current; current = current->storedPrototype().isNull() ? 0 : asObject(current->storedPrototype())->structure())
  68                 ++size;
  69
  70             m_vector = adoptArrayPtr(new WriteBarrier<Structure>[size + 1]);
  71
  72             size_t i = 0;
  73             for (Structure* current = head; current; current = current->storedPrototype().isNull() ? 0 : asObject(current->storedPrototype())->structure())
  74                 m_vector[i++].set(globalData, this, current);
  75         }
  76
  77     private:
  78         friend class LLIntOffsetsExtractor;
  79
  80         StructureChain(JSGlobalData&, Structure*);
  81         static void destroy(JSCell*);
  82         OwnArrayPtr<WriteBarrier<Structure> > m_vector;
  83     };
  84
  85 } // namespace JSC
  86
  87 #endif // StructureChain_h