weex_core/Source/include/JavaScriptCore/runtime/PropertyNameArray.h

/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
#pragma once

#include "CallFrame.h"
#include "Identifier.h"
#include <wtf/HashSet.h>
#include <wtf/Vector.h>

namespace JSC {

// FIXME: Rename to PropertyNameArray.
class PropertyNameArrayData : public RefCounted<PropertyNameArrayData> {
public:
    typedef Vector<Identifier, 20> PropertyNameVector;

    static Ref<PropertyNameArrayData> create() { return adoptRef(*new PropertyNameArrayData); }

    PropertyNameVector& propertyNameVector() { return m_propertyNameVector; }

private:
    PropertyNameArrayData()
    {
    }

    PropertyNameVector m_propertyNameVector;
};

// FIXME: Rename to PropertyNameArrayBuilder.
class PropertyNameArray {
public:
    PropertyNameArray(VM* vm, PropertyNameMode mode)
        : m_data(PropertyNameArrayData::create())
        , m_vm(vm)
        , m_mode(mode)
    {
    }

    PropertyNameArray(ExecState* exec, PropertyNameMode mode)
        : PropertyNameArray(&exec->vm(), mode)
    {
    }

    VM* vm() { return m_vm; }

    void add(uint32_t index)
    {
        add(Identifier::from(m_vm, index));
    }

    void add(const Identifier&);
    void add(UniquedStringImpl*);
    void addUnchecked(UniquedStringImpl*);

    Identifier& operator[](unsigned i) { return m_data->propertyNameVector()[i]; }
    const Identifier& operator[](unsigned i) const { return m_data->propertyNameVector()[i]; }

    PropertyNameArrayData* data() { return m_data.get(); }
    RefPtr<PropertyNameArrayData> releaseData() { return WTFMove(m_data); }

    // FIXME: Remove these functions.
    bool canAddKnownUniqueForStructure() const { return m_data->propertyNameVector().isEmpty(); }
    typedef PropertyNameArrayData::PropertyNameVector::const_iterator const_iterator;
    size_t size() const { return m_data->propertyNameVector().size(); }
    const_iterator begin() const { return m_data->propertyNameVector().begin(); }
    const_iterator end() const { return m_data->propertyNameVector().end(); }

    PropertyNameMode mode() const { return m_mode; }
    bool includeSymbolProperties() const;
    bool includeStringProperties() const;

private:
    bool isUidMatchedToTypeMode(UniquedStringImpl* identifier);

    RefPtr<PropertyNameArrayData> m_data;
    HashSet<UniquedStringImpl*> m_set;
    VM* m_vm;
    PropertyNameMode m_mode;
};

ALWAYS_INLINE void PropertyNameArray::add(const Identifier& identifier)
{
    add(identifier.impl());
}

ALWAYS_INLINE void PropertyNameArray::addUnchecked(UniquedStringImpl* identifier)
{
    if (!isUidMatchedToTypeMode(identifier))
        return;
    m_data->propertyNameVector().append(Identifier::fromUid(m_vm, identifier));
}

ALWAYS_INLINE void PropertyNameArray::add(UniquedStringImpl* identifier)
{
    static const unsigned setThreshold = 20;

    ASSERT(identifier);

    if (!isUidMatchedToTypeMode(identifier))
        return;

    if (size() < setThreshold) {
        if (m_data->propertyNameVector().contains(identifier))
            return;
    } else {
        if (m_set.isEmpty()) {
            for (Identifier& name : m_data->propertyNameVector())
                m_set.add(name.impl());
        }
        if (!m_set.add(identifier).isNewEntry)
            return;
    }

    addUnchecked(identifier);
}

ALWAYS_INLINE bool PropertyNameArray::isUidMatchedToTypeMode(UniquedStringImpl* identifier)
{
    if (identifier->isSymbol())
        return includeSymbolProperties();
    return includeStringProperties();
}

ALWAYS_INLINE bool PropertyNameArray::includeSymbolProperties() const
{
    return static_cast<std::underlying_type<PropertyNameMode>::type>(m_mode) & static_cast<std::underlying_type<PropertyNameMode>::type>(PropertyNameMode::Symbols);
}

ALWAYS_INLINE bool PropertyNameArray::includeStringProperties() const
{
    return static_cast<std::underlying_type<PropertyNameMode>::type>(m_mode) & static_cast<std::underlying_type<PropertyNameMode>::type>(PropertyNameMode::Strings);
}

} // namespace JSC