runtime/JSMapIterator.h

   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. ``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 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 JSMapIterator_h
  27 #define JSMapIterator_h
  28
  29 #include "JSDestructibleObject.h"
  30 #include "JSMap.h"
  31 #include "MapData.h"
  32
  33 namespace JSC {
  34 enum MapIterationKind : uint32_t {
  35     MapIterateKey,
  36     MapIterateValue,
  37     MapIterateKeyValue,
  38 };
  39
  40 class JSMapIterator : public JSDestructibleObject {
  41 public:
  42     typedef JSDestructibleObject Base;
  43
  44     DECLARE_EXPORT_INFO;
  45
  46     static Structure* createStructure(VM& vm, JSGlobalObject* globalObject, JSValue prototype)
  47     {
  48         return Structure::create(vm, globalObject, prototype, TypeInfo(ObjectType, StructureFlags), info());
  49     }
  50
  51     static JSMapIterator* create(VM& vm, Structure* structure, JSMap* iteratedObject, MapIterationKind kind)
  52     {
  53         JSMapIterator* instance = new (NotNull, allocateCell<JSMapIterator>(vm.heap)) JSMapIterator(vm, structure, iteratedObject, kind);
  54         instance->finishCreation(vm, iteratedObject);
  55         return instance;
  56     }
  57
  58     bool next(CallFrame* callFrame, JSValue& value)
  59     {
  60         if (!m_iterator.ensureSlot())
  61             return false;
  62
  63         if (m_kind == MapIterateValue)
  64             value = m_iterator.value();
  65         else if (m_kind == MapIterateKey)
  66             value = m_iterator.key();
  67         else
  68             value = createPair(callFrame, m_iterator.key(), m_iterator.value());
  69         ++m_iterator;
  70         return true;
  71     }
  72
  73 private:
  74
  75     static const unsigned StructureFlags = Base::StructureFlags | OverridesVisitChildren;
  76
  77     JSMapIterator(VM& vm, Structure* structure, JSMap* iteratedObject, MapIterationKind kind)
  78         : Base(vm, structure)
  79         , m_iterator(iteratedObject->mapData()->begin())
  80         , m_kind(kind)
  81     {
  82     }
  83
  84     void finishCreation(VM&, JSMap*);
  85     JSValue createPair(CallFrame*, JSValue, JSValue);
  86     static void visitChildren(JSCell*, SlotVisitor&);
  87
  88     WriteBarrier<MapData> m_iteratedObjectData;
  89     MapData::const_iterator m_iterator;
  90     MapIterationKind m_kind;
  91 };
  92
  93 }
  94
  95 #endif // !defined(JSMapIterator_h)