/****************************************************************************

**

** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).

** All rights reserved.

** Contact: Nokia Corporation (qt-info@nokia.com)

**

** This file is part of the QtXmlPatterns module of the Qt Toolkit.

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** $QT_BEGIN_LICENSE:LGPL$

** GNU Lesser General Public License Usage

** This file may be used under the terms of the GNU Lesser General Public

** License version 2.1 as published by the Free Software Foundation and

** appearing in the file LICENSE.LGPL included in the packaging of this

** file. Please review the following information to ensure the GNU Lesser

** General Public License version 2.1 requirements will be met:

** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.

**

** In addition, as a special exception, Nokia gives you certain additional

** rights. These rights are described in the Nokia Qt LGPL Exception

** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.

**

** GNU General Public License Usage

** Alternatively, this file may be used under the terms of the GNU General

** Public License version 3.0 as published by the Free Software Foundation

** and appearing in the file LICENSE.GPL included in the packaging of this

** file. Please review the following information to ensure the GNU General

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** $QT_END_LICENSE$

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****************************************************************************/

//

//  W A R N I N G

//  -------------

//

// This file is not part of the Qt API.  It exists purely as an

// implementation detail.  This header file may change from version to

// version without notice, or even be removed.

//

// We mean it.

#ifndef Patternist_NamePool_H

#define Patternist_NamePool_H

#include <QHash>

#include <QReadLocker>

#include <QReadWriteLock>

#include <QSharedData>

#include <QString>

#include <QVector>

#include <QXmlName>

#include <QtXmlPatterns/private/qprimitives_p.h>

QT_BEGIN_HEADER

QT_BEGIN_NAMESPACE

namespace QPatternist

{

    /**

     * @short Store names such as namespace bindings and QNames and allows them to

     * be referenced in efficient ways.

     *

     * Once a string have been inserted it stays there and cannot be removed. The

     * only way to deallocate any string in the NamePool is to deallocate the

     * NamePool itself, as a whole.

     *

     * This class is not only reentrant, it is thread-safe in all sense of the

     * word. All functions of this class can be called concurrently. This is

     * achieved by internal locking.

     *

     * @author Frans Englich <frans.englich@nokia.com>

     * @todo Use QSubStrings, we can save very many heap allocations by that.

     * @todo Check limits

     */

    class Q_AUTOTEST_EXPORT NamePool : public QSharedData

    {

    public:

        typedef QExplicitlySharedDataPointer<NamePool> Ptr;

    private:

        friend class StandardNamespaces;

        enum

        {

            NoSuchValue         = -1,

            /**

             * This must be identical to the amount of members in

             * StandardNamespaces.

             */

            StandardNamespaceCount = 11,

            StandardPrefixCount = 9,

            StandardLocalNameCount = 141

        };

        QVector<QString> m_prefixes;

        QVector<QString> m_namespaces;

        QVector<QString> m_localNames;

        /**

         * This hash contains no essential data, but speeds up

         * finding a prefix in m_prefixes by mapping a prefix(the key) to

         * the index into m_prefixes(which the value is).

         *

         * In other words, one can skip this variable at the cost of having

         * to linearly loop over prefixes, in order to find the entry.

         */

        QHash<QString, QXmlName::PrefixCode> m_prefixMapping;

        /**

         * Same as m_prefixMapping but applies for URIs, and hence m_namespaces instead

         * of m_prefixes.

         */

        QHash<QString, QXmlName::NamespaceCode> m_namespaceMapping;

        QHash<QString, QXmlName::LocalNameCode> m_localNameMapping;

        enum DefaultCapacities

        {

            DefaultPrefixCapacity = 10,

            DefaultURICapacity = DefaultPrefixCapacity,

            /**

             * It looks like it's quite common with 40-60 different local names per XML

             * vocabulary. For background, see:

             *

             * - http://englich.wordpress.com/2007/01/11/representing-xml/

             * - http://englich.wordpress.com/2007/01/09/xmlstat/

             */

            DefaultLocalNameCapacity = 60

        };

    public:

        NamePool();

        /**

         * @short Allocates a namespace binding for @p prefix and @p uri.

         *

         * In the returned QXmlName, the local name is

         * StandardLocalNames::empty, and QXmlName::prefix() and

         * QXmlName::namespaceUri() returns @p prefix and @p uri, respectively.

         *

         * In older versions of this code, the class NamespaceBinding existed,

         * but as part of having the public class QXmlName, it was dropped and

         * a special interpretation/convention involving use of QXmlName was

         * adopted.

         */

        QXmlName allocateBinding(const QString &prefix, const QString &uri);

        QXmlName allocateQName(const QString &uri, const QString &localName, const QString &prefix = QString());

        inline QXmlName allocateQName(const QXmlName::NamespaceCode uri, const QString &ln)

        {

            /* We don't lock here, but we do in allocateLocalName(). */

            return QXmlName(uri, allocateLocalName(ln));

        }

        inline const QString &stringForLocalName(const QXmlName::LocalNameCode code) const

        {

            const QReadLocker l(&lock);

            return m_localNames.at(code);

        }

        inline const QString &stringForPrefix(const QXmlName::PrefixCode code) const

        {

            const QReadLocker l(&lock);

            return m_prefixes.at(code);

        }

        inline const QString &stringForNamespace(const QXmlName::NamespaceCode code) const

        {

            const QReadLocker l(&lock);

            return m_namespaces.at(code);

        }

        QString displayName(const QXmlName qName) const;

        inline QString toLexical(const QXmlName qName) const

        {

            const QReadLocker l(&lock);

            Q_ASSERT_X(!qName.isNull(), "", "It makes no sense to call toLexical() on a null name.");

            if(qName.hasPrefix())

            {

                const QString &p = m_prefixes.at(qName.prefix());

                return p + QLatin1Char(':') + m_localNames.at(qName.localName());

            }

            else

                return m_localNames.at(qName.localName());

        }

        inline QXmlName::NamespaceCode allocateNamespace(const QString &uri)

        {

            const QWriteLocker l(&lock);

            return unlockedAllocateNamespace(uri);

        }

        inline QXmlName::LocalNameCode allocateLocalName(const QString &ln)

        {

            const QWriteLocker l(&lock);

            return unlockedAllocateLocalName(ln);

        }

        inline QXmlName::PrefixCode allocatePrefix(const QString &prefix)

        {

            const QWriteLocker l(&lock);

            return unlockedAllocatePrefix(prefix);

        }

        QString toClarkName(const QXmlName &name) const;

        QXmlName fromClarkName(const QString &clarkName);

    private:

        /**

         * @note This function can not be called concurrently.

         */

        QXmlName::NamespaceCode unlockedAllocateNamespace(const QString &uri);

        /**

         * @note This function can not be called concurrently.

         */

        QXmlName::LocalNameCode unlockedAllocateLocalName(const QString &ln);

        /**

         * It's assumed that @p prefix is a valid @c NCName.

         *

         * @note This function can not be called concurrently.

         */

        QXmlName::PrefixCode unlockedAllocatePrefix(const QString &prefix);

        Q_DISABLE_COPY(NamePool)

        /**

         * @note This function can not be called concurrently.

         */

        const QString &displayPrefix(const QXmlName::NamespaceCode nc) const;

        mutable QReadWriteLock lock;

    };

    /**

     * @short Formats QName.

     *

     * @relates QXmlName

     */

    static inline QString formatKeyword(const NamePool::Ptr &np, const QXmlName name)

    {

        return QLatin1String("<span class='XQuery-keyword'>")   +

               escape(np->displayName(name))                    +

               QLatin1String("</span>");

    }

    /**

     * @see NamespaceResolver::Constants

     */

    class StandardNamespaces

    {

    public:

        enum ID

        {

            /**

             * This does not mean empty in the sense of "empty", but

             * in the sense of an empty string, "".

             *

             * Its value, zero, is significant.

             */

            empty = 0,

            fn,

            local,

            xml,

            xmlns,

            xs,

            xsi,

            xslt,

            /**

             * @short A special value that when passed as the namespace part

             * to NamespaceResolver::addBinding(), undeclares the prefix.

             *

             * This is used by the namespace prolog declaration.

             *

             * A dummy value is added to the name pool.

             */

            UndeclarePrefix,

            /**

             * Signals that a node shouldn't inherit namespaces from its parent. Must be used

             * with StandardPrefixes::StopNamespaceInheritance.

             */

            StopNamespaceInheritance,

            /**

             * A namespace used to identify for instance @c \#all template

             * mode in XSL-T.

             */

            InternalXSLT

        };

    };

    // const QString * a = &*qset.insert("foo");

    class StandardLocalNames

    {

    public:

        enum

        {

            abs,

            adjust_dateTime_to_timezone,

            adjust_date_to_timezone,

            adjust_time_to_timezone,

            all,

            arity,

            avg,

            base,

            base_uri,

            boolean,

            ceiling,

            codepoint_equal,

            codepoints_to_string,

            collection,

            compare,

            concat,

            contains,

            count,

            current,

            current_date,

            current_dateTime,

            current_time,

            data,

            dateTime,

            day_from_date,

            day_from_dateTime,

            days_from_duration,

            deep_equal,

            Default,

            default_collation,

            distinct_values,

            doc,

            doc_available,

            document,

            document_uri,

            element_available,

            empty,

            encode_for_uri,

            ends_with,

            error,

            escape_html_uri,

            exactly_one,

            exists,

            False,

            floor,

            function_available,

            function_name,

            generate_id,

            generic_string_join,

            hours_from_dateTime,

            hours_from_duration,

            hours_from_time,

            id,

            idref,

            implicit_timezone,

            index_of,

            in_scope_prefixes,

            insert_before,

            iri_to_uri,

            is_schema_aware,

            key,

            lang,

            last,

            local_name,

            local_name_from_QName,

            lower_case,

            matches,

            max,

            min,

            minutes_from_dateTime,

            minutes_from_duration,

            minutes_from_time,

            month_from_date,

            month_from_dateTime,

            months_from_duration,

            name,

            namespace_uri,

            namespace_uri_for_prefix,

            namespace_uri_from_QName,

            nilled,

            node_name,

            normalize_space,

            normalize_unicode,

            Not,

            number,

            one_or_more,

            position,

            prefix_from_QName,

            product_name,

            product_version,

            property_name,

            QName,

            remove,

            replace,

            resolve_QName,

            resolve_uri,

            reverse,

            root,

            round,

            round_half_to_even,

            seconds_from_dateTime,

            seconds_from_duration,

            seconds_from_time,

            sourceValue,

            starts_with,

            static_base_uri,

            string,

            string_join,

            string_length,

            string_to_codepoints,

            subsequence,

            substring,

            substring_after,

            substring_before,

            sum,

            supports_backwards_compatibility,

            supports_serialization,

            system_property,

            timezone_from_date,

            timezone_from_dateTime,

            timezone_from_time,

            tokenize,

            trace,

            translate,

            True,

            type_available,

            unordered,

            unparsed_entity_public_id,

            unparsed_entity_uri,

            unparsed_text,

            unparsed_text_available,

            upper_case,

            vendor,

            vendor_url,

            version,

            xml,

            xmlns,

            year_from_date,

            year_from_dateTime,

            years_from_duration,

            zero_or_one

        };

    };

    class StandardPrefixes

    {

    public:

        enum

        {

            /**

             * This does not mean empty in the sense of "empty", but

             * in the sense of an empty string, "".

             *

             * Its value, zero, is significant.

             */

            empty = 0,

            fn,

            local,

            xml,

            xmlns,

            xs,

            xsi,

            ns0,

            StopNamespaceInheritance

        };

    };

}

inline QXmlName::LocalNameCode QXmlName::localName() const

{

    return (m_qNameCode & LocalNameMask) >> LocalNameOffset;

}

inline QXmlName::PrefixCode QXmlName::prefix() const

{

    return (m_qNameCode & PrefixMask) >> PrefixOffset;

}

inline bool QXmlName::hasPrefix() const

{

    return prefix() != 0;

}

inline bool QXmlName::hasNamespace() const

{

    return namespaceURI() != 0;

}

inline QXmlName::NamespaceCode QXmlName::namespaceURI() const

{

    return (m_qNameCode & NamespaceMask) >> NamespaceOffset;

}

inline bool QXmlName::isLexicallyEqual(const QXmlName &other) const

{

    return (m_qNameCode & LexicalQNameMask) == (other.m_qNameCode & LexicalQNameMask);

}

inline void QXmlName::setPrefix(const PrefixCode c)

{

    m_qNameCode |= (c << PrefixOffset);

}

inline void QXmlName::setNamespaceURI(const NamespaceCode c)

{

    m_qNameCode |= (c << NamespaceOffset);

}

inline void QXmlName::setLocalName(const LocalNameCode c)

{

    m_qNameCode |= (c << LocalNameOffset);

}

inline QXmlName::Code QXmlName::code() const

{

    return m_qNameCode;

}

inline QXmlName::QXmlName(const NamespaceCode uri,

                          const LocalNameCode ln,

                          const PrefixCode p) : m_qNameCode((uri << NamespaceOffset) +

                                                            (ln << LocalNameOffset)  +

                                                            (p << PrefixOffset))

{

    /* We can't use members like prefix() here because if one of the

     * values are to large, they would overflow into the others. */

    Q_ASSERT_X(p <= MaximumPrefixes, "",

               qPrintable(QString::fromLatin1("NamePool prefix limits: max is %1, therefore %2 exceeds.").arg(MaximumPrefixes).arg(p)));

    Q_ASSERT_X(ln <= MaximumLocalNames, "",

               qPrintable(QString::fromLatin1("NamePool local name limits: max is %1, therefore %2 exceeds.").arg(MaximumLocalNames).arg(ln)));

    Q_ASSERT_X(uri <= MaximumNamespaces, "",

               qPrintable(QString::fromLatin1("NamePool namespace limits: max is %1, therefore %2 exceeds.").arg(MaximumNamespaces).arg(uri)));

}

Q_DECLARE_TYPEINFO(QPatternist::NamePool::Ptr, Q_MOVABLE_TYPE);

QT_END_NAMESPACE

QT_END_HEADER

#endif