libkf5kjs-dev 5.18.0-0ubuntu1 / usr / include / KF5 / kjs / property_map.h

/*
 *  This file is part of the KDE libraries
 *  Copyright (C) 2004, 2005, 2006, 2007 Apple Computer, Inc.
 *  Copyright (C) 2007 Christopher E. Hyde <C.Hyde@parableuk.force9.co.uk>
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Library General Public
 *  License as published by the Free Software Foundation; either
 *  version 2 of the License, or (at your option) any later version.
 *
 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Library General Public License for more details.
 *
 *  You should have received a copy of the GNU Library General Public License
 *  along with this library; see the file COPYING.LIB.  If not, write to
 *  the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 *  Boston, MA 02110-1301, USA.
 *
 */

#ifndef KJS_PROPERTY_MAP_H_
#define KJS_PROPERTY_MAP_H_

#include "identifier.h"
#include <wtf/OwnArrayPtr.h>

namespace KJS
{

class PropertyNameArray;
class JSValue;

class SavedProperty;

struct PropertyMapHashTable;

// ECMA 262-3 8.6.1
// Property attributes
enum Attribute { None         = 0,
                 ReadOnly     = 1 << 1, // property can be only read, not written
                 DontEnum     = 1 << 2, // property doesn't appear in (for .. in ..)
                 DontDelete   = 1 << 3, // property can't be deleted
                 Internal     = 1 << 4, // an internal property, set to bypass checks
                 Function     = 1 << 5, // property is a function - only used by static hashtables
                 GetterSetter = 1 << 6, // property is a getter or setter
                 DontMark     = 1 << 7
               }; // used in locals arrays only --- indicates that the slot
// does not contain a value, and hence should not be marked.

/*
* Saved Properties
*/
class SavedProperties
{
    friend class PropertyMap;
public:
    SavedProperties();
    ~SavedProperties();

private:
    int _count;
    OwnArrayPtr<SavedProperty> _properties;
};

/*
* A hashtable entry for the @ref PropertyMap.
*/
struct PropertyMapHashTableEntry {
    PropertyMapHashTableEntry() : key(0) { }
    UString::Rep *key;
    JSValue *value;
    int attributes;
    int index;
};

/**
* Javascript Property Map.
*/
class KJS_EXPORT PropertyMap
{
    friend class JSObject;
public:
    enum PropertyMode {
        ExcludeDontEnumProperties,
        IncludeDontEnumProperties
    };

    PropertyMap();
    ~PropertyMap();

    void clear();

    void put(const Identifier &name, JSValue *value, int attributes, bool roCheck = false);
    void remove(const Identifier &name);
    JSValue *get(const Identifier &name) const;
    JSValue *get(const Identifier &name, unsigned &attributes) const;
    JSValue **getLocation(const Identifier &name);

    // Returns a location where this property can be set, if it
    // exists, is writeable, and not a setter.
    // Warning: this pointer may become invalid after any further modifications
    JSValue **getWriteLocation(const Identifier &name);

    void mark() const;
    static inline bool checkEnumerable(unsigned int attr, PropertyMode mode)
    {
        return (!(attr & DontEnum) || mode == PropertyMap::IncludeDontEnumProperties);
    }
    void getPropertyNames(PropertyNameArray &, PropertyMode mode = ExcludeDontEnumProperties) const;

    void save(SavedProperties &) const;
    void restore(const SavedProperties &p);

    bool isEmpty() const;

    bool hasGetterSetterProperties() const
    {
        return m_getterSetterFlag;
    }
    void setHasGetterSetterProperties(bool f)
    {
        m_getterSetterFlag = f;
    }

    void setExtensible(bool extensible)
    {
        m_extensible = extensible;
    }
    bool isExtensible() const
    {
        return m_extensible;
    }

    // This /computes/ whether the table has getters or setters, while the above is
    // used to cache the result. In other words, one usually does
    // setHasGetterSetterProperties(containsGettersOrSetters()) whenver
    // there is a reason to believe that the result has changed
    bool containsGettersOrSetters() const;
private:
    static bool keysMatch(const UString::Rep *, const UString::Rep *);
    void expand();
    void rehash();
    void rehash(int newTableSize);
    void createTable();

    void insert(UString::Rep *, JSValue *value, int attributes, int index);

    void checkConsistency();

    typedef PropertyMapHashTableEntry Entry;
    typedef PropertyMapHashTable Table;

    UString::Rep *m_singleEntryKey;
    union {
        JSValue *singleEntryValue;
        Table *table;
    } m_u;

    short m_singleEntryAttributes;

    bool m_getterSetterFlag : 1;
    bool m_usingTable       : 1;
    bool m_extensible       : 1;

    // We also stick some of the object's
    // bitflags here. Kind of ugly, but saves memory...
    bool m_objLocalInjected : 1;
};

inline PropertyMap::PropertyMap() :
    m_singleEntryKey(0),
    m_getterSetterFlag(false),
    m_usingTable(false),
    m_extensible(true),
    m_objLocalInjected(false)
{}
} // namespace

#endif // _KJS_PROPERTY_MAP_H_