Source/JavaScriptCore/runtime/JSSet.cpp

/*
 * Copyright (C) 2013, 2016 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:
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 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE 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 INC. OR
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#include "config.h"
#include "JSSet.h"

#include "JSCInlines.h"

namespace JSC {

const ClassInfo JSSet::s_info = { "Set", &Base::s_info, nullptr, nullptr, CREATE_METHOD_TABLE(JSSet) };

JSSet* JSSet::clone(JSGlobalObject* globalObject, VM& vm, Structure* structure)
{
    JSSet* instance = new (NotNull, allocateCell<JSSet>(vm.heap)) JSSet(vm, structure);
    instance->finishCreation(globalObject, vm, this);
    return instance;
}

bool JSSet::isIteratorProtocolFastAndNonObservable()
{
    JSGlobalObject* globalObject = this->globalObject();
    if (!globalObject->isSetPrototypeIteratorProtocolFastAndNonObservable())
        return false;

    VM& vm = globalObject->vm();
    Structure* structure = this->structure(vm);
    // This is the fast case. Many sets will be an original set.
    if (structure == globalObject->setStructure())
        return true;

    if (getPrototypeDirect(vm) != globalObject->jsSetPrototype())
        return false;

    if (getDirectOffset(vm, vm.propertyNames->iteratorSymbol) != invalidOffset)
        return false;

    return true;
}

bool JSSet::canCloneFastAndNonObservable(Structure* structure)
{
    auto addFastAndNonObservable = [&] (Structure* structure) {
        JSGlobalObject* globalObject = structure->globalObject();
        if (!globalObject->isSetPrototypeAddFastAndNonObservable())
            return false;

        if (structure->hasPolyProto())
            return false;

        if (structure->storedPrototype() != globalObject->jsSetPrototype())
            return false;

        return true;
    };

    return isIteratorProtocolFastAndNonObservable() && addFastAndNonObservable(structure);
}

}