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

** 

**

** Definition of QGCache and QGCacheIterator classes

**

** Created : 950208

**

** Copyright (C) 1992-2000 Trolltech AS.  All rights reserved.

**

** This file is part of the tools module of the Qt GUI Toolkit.

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** as defined by Trolltech AS of Norway and appearing in the file

** LICENSE.QPL included in the packaging of this file.

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** This file may be distributed and/or modified under the terms of the

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** Foundation and appearing in the file LICENSE.GPL included in the

** packaging of this file.

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** licenses may use this file in accordance with the Qt Commercial License

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

#ifndef QGCACHE_H

#define QGCACHE_H

#ifndef QT_H

#include "qcollection.h"

#include "qglist.h"

#include "qgdict.h"

#endif // QT_H

class QCList;					// internal classes

class QCListIt;

class QCDict;

class Q_EXPORT QGCache : public QCollection	// generic LRU cache

{

friend class QGCacheIterator;

protected:

    enum KeyType { StringKey, AsciiKey, IntKey, PtrKey };

      // identical to QGDict's, but PtrKey is not used at the moment

    QGCache( int maxCost, uint size, KeyType kt, bool caseSensitive,

	     bool copyKeys );

    QGCache( const QGCache & );			// not allowed, calls fatal()

   ~QGCache();

    QGCache &operator=( const QGCache & );	// not allowed, calls fatal()

    uint    count()	const	{ return ((QGDict*)dict)->count(); }

    uint    size()	const	{ return ((QGDict*)dict)->size(); }

    int	    maxCost()	const	{ return mCost; }

    int	    totalCost() const	{ return tCost; }

    void    setMaxCost( int maxCost );

    void    clear();

    bool    insert_string( const QString &key, QCollection::Item,

			   int cost, int priority );

    bool    insert_other( const char *key, QCollection::Item,

			  int cost, int priority );

    bool    remove_string( const QString &key );

    bool    remove_other( const char *key );

    QCollection::Item take_string( const QString &key );

    QCollection::Item take_other( const char *key );

    QCollection::Item find_string( const QString &key, bool ref=TRUE ) const;

    QCollection::Item find_other( const char *key, bool ref=TRUE ) const;

    void    statistics() const;

private:

    bool    makeRoomFor( int cost, int priority = -1 );

    KeyType keytype;

    QCList *lruList;

    QCDict *dict;

    int	    mCost;

    int	    tCost;

    bool    copyk;

};

class Q_EXPORT QGCacheIterator			// generic cache iterator

{

protected:

    QGCacheIterator( const QGCache & );

    QGCacheIterator( const QGCacheIterator & );

   ~QGCacheIterator();

    QGCacheIterator &operator=( const QGCacheIterator & );

    uint	      count()   const;

    bool	      atFirst() const;

    bool	      atLast()  const;

    QCollection::Item toFirst();

    QCollection::Item toLast();

    QCollection::Item get() const;

    QString	      getKeyString() const;

    const char       *getKeyAscii()  const;

    long	      getKeyInt()    const;

    QCollection::Item operator()();

    QCollection::Item operator++();

    QCollection::Item operator+=( uint );

    QCollection::Item operator--();

    QCollection::Item operator-=( uint );

protected:

    QCListIt *it;				// iterator on cache list

};

#endif // QGCACHE_H