runtime/PutPropertySlot.h

   1 // -*- mode: c++; c-basic-offset: 4 -*-
   2 /*
   3  * Copyright (C) 2008 Apple Inc. All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
  15  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  17  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
  18  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  19  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  20  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  21  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  22  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  24  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25  */
  26
  27 #ifndef PutPropertySlot_h
  28 #define PutPropertySlot_h
  29
  30 #include <wtf/Assertions.h>
  31
  32 namespace JSC {
  33
  34     class JSObject;
  35     class JSFunction;
  36
  37     class PutPropertySlot {
  38     public:
  39         enum Type { Uncachable, ExistingProperty, NewProperty };
  40
  41         PutPropertySlot()
  42             : m_type(Uncachable)
  43             , m_base(0)
  44         {
  45         }
  46
  47         void setExistingProperty(JSObject* base, size_t offset)
  48         {
  49             m_type = ExistingProperty;
  50             m_base = base;
  51             m_offset = offset;
  52         }
  53
  54         void setNewProperty(JSObject* base, size_t offset)
  55         {
  56             m_type = NewProperty;
  57             m_base = base;
  58             m_offset = offset;
  59         }
  60
  61         Type type() const { return m_type; }
  62         JSObject* base() const { return m_base; }
  63
  64         bool isCacheable() const { return m_type != Uncachable; }
  65         size_t cachedOffset() const {
  66             ASSERT(isCacheable());
  67             return m_offset;
  68         }
  69     private:
  70         Type m_type;
  71         JSObject* m_base;
  72         size_t m_offset;
  73     };
  74
  75 } // namespace JSC
  76
  77 #endif // PutPropertySlot_h