/*

 * Copyright (C) 2005, 2006, 2009 Apple Inc. All rights reserved.

 *

 * 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 QualifiedName_h

#define QualifiedName_h

#include "AtomicString.h"

#include <wtf/HashTraits.h>

namespace WebCore {

struct QualifiedNameComponents {

    StringImpl* m_prefix;

    StringImpl* m_localName;

    StringImpl* m_namespace;

};

class QualifiedName : public FastAllocBase {

public:

    class QualifiedNameImpl : public RefCounted<QualifiedNameImpl> {

    public:

        static PassRefPtr<QualifiedNameImpl> create(const AtomicString& prefix, const AtomicString& localName, const AtomicString& namespaceURI)

        {

            return adoptRef(new QualifiedNameImpl(prefix, localName, namespaceURI));

        }

        const AtomicString m_prefix;

        const AtomicString m_localName;

        const AtomicString m_namespace;

        mutable AtomicString m_localNameUpper;

    private:

        QualifiedNameImpl(const AtomicString& prefix, const AtomicString& localName, const AtomicString& namespaceURI)

            : m_prefix(prefix)

            , m_localName(localName)

            , m_namespace(namespaceURI)

        {

            ASSERT(!namespaceURI.isEmpty() || namespaceURI.isNull());

        }        

    };

    QualifiedName(const AtomicString& prefix, const AtomicString& localName, const AtomicString& namespaceURI);

    QualifiedName(const AtomicString& prefix, const char* localName, const AtomicString& namespaceURI);

    QualifiedName(WTF::HashTableDeletedValueType) : m_impl(hashTableDeletedValue()) { }

    bool isHashTableDeletedValue() const { return m_impl == hashTableDeletedValue(); }

    ~QualifiedName() { deref(); }

#ifdef QNAME_DEFAULT_CONSTRUCTOR

    QualifiedName() : m_impl(0) { }

#endif

    QualifiedName(const QualifiedName& other) : m_impl(other.m_impl) { ref(); }

    const QualifiedName& operator=(const QualifiedName& other) { other.ref(); deref(); m_impl = other.m_impl; return *this; }

    bool operator==(const QualifiedName& other) const { return m_impl == other.m_impl; }

    bool operator!=(const QualifiedName& other) const { return !(*this == other); }

    bool matches(const QualifiedName& other) const { return m_impl == other.m_impl || (localName() == other.localName() && namespaceURI() == other.namespaceURI()); }

    bool hasPrefix() const { return m_impl->m_prefix != nullAtom; }

    void setPrefix(const AtomicString& prefix) { *this = QualifiedName(prefix, localName(), namespaceURI()); }

    const AtomicString& prefix() const { return m_impl->m_prefix; }

    const AtomicString& localName() const { return m_impl->m_localName; }

    const AtomicString& namespaceURI() const { return m_impl->m_namespace; }

    // Uppercased localName, cached for efficiency

    const AtomicString& localNameUpper() const;

    String toString() const;

    QualifiedNameImpl* impl() const { return m_impl; }

    // Init routine for globals

    static void init();

private:

    void init(const AtomicString& prefix, const AtomicString& localName, const AtomicString& namespaceURI);

    void ref() const { m_impl->ref(); }

    void deref();

    static QualifiedNameImpl* hashTableDeletedValue() { return RefPtr<QualifiedNameImpl>::hashTableDeletedValue(); }

    QualifiedNameImpl* m_impl;

};

#ifndef WEBCORE_QUALIFIEDNAME_HIDE_GLOBALS

extern const QualifiedName anyName;

inline const QualifiedName& anyQName() { return anyName; }

#endif

inline bool operator==(const AtomicString& a, const QualifiedName& q) { return a == q.localName(); }

inline bool operator!=(const AtomicString& a, const QualifiedName& q) { return a != q.localName(); }

inline bool operator==(const QualifiedName& q, const AtomicString& a) { return a == q.localName(); }

inline bool operator!=(const QualifiedName& q, const AtomicString& a) { return a != q.localName(); }

inline unsigned hashComponents(const QualifiedNameComponents& buf)

{

    ASSERT(sizeof(QualifiedNameComponents) % (sizeof(uint16_t) * 2) == 0);

    unsigned l = sizeof(QualifiedNameComponents) / (sizeof(uint16_t) * 2);

    const uint16_t* s = reinterpret_cast<const uint16_t*>(&buf);

    uint32_t hash = WTF::stringHashingStartValue;

    // Main loop

    for (; l > 0; l--) {

        hash += s[0];

        uint32_t tmp = (s[1] << 11) ^ hash;

        hash = (hash << 16) ^ tmp;

        s += 2;

        hash += hash >> 11;

    }

    // Force "avalanching" of final 127 bits

    hash ^= hash << 3;

    hash += hash >> 5;

    hash ^= hash << 2;

    hash += hash >> 15;

    hash ^= hash << 10;

    // this avoids ever returning a hash code of 0, since that is used to

    // signal "hash not computed yet", using a value that is likely to be

    // effectively the same as 0 when the low bits are masked

    if (hash == 0)

        hash = 0x80000000;

    return hash;

}

struct QualifiedNameHash {

    static unsigned hash(const QualifiedName& name) { return hash(name.impl()); }

    static unsigned hash(const QualifiedName::QualifiedNameImpl* name) 

    {    

        QualifiedNameComponents c = { name->m_prefix.impl(), name->m_localName.impl(), name->m_namespace.impl() };

        return hashComponents(c);

    }

    static bool equal(const QualifiedName& a, const QualifiedName& b) { return a == b; }

    static bool equal(const QualifiedName::QualifiedNameImpl* a, const QualifiedName::QualifiedNameImpl* b) { return a == b; }

    static const bool safeToCompareToEmptyOrDeleted = false;

};

}

namespace WTF {

    template<typename T> struct DefaultHash;

    template<> struct DefaultHash<WebCore::QualifiedName> {

        typedef WebCore::QualifiedNameHash Hash;

    };

    template<> struct HashTraits<WebCore::QualifiedName> : GenericHashTraits<WebCore::QualifiedName> {

        static const bool emptyValueIsZero = false;

        static WebCore::QualifiedName emptyValue() { return WebCore::QualifiedName(WebCore::nullAtom, WebCore::nullAtom, WebCore::nullAtom); }

        static void constructDeletedValue(WebCore::QualifiedName& slot) { new (&slot) WebCore::QualifiedName(WTF::HashTableDeletedValue); }

        static bool isDeletedValue(const WebCore::QualifiedName& slot) { return slot.isHashTableDeletedValue(); }

    };

}

#endif