--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/menufw/hierarchynavigator/hnmetadatamodel/inc/hnxmlmodelcache.h	Thu Dec 17 08:40:49 2009 +0200
@@ -0,0 +1,164 @@
+/*
+* Copyright (c) 2007-2008 Nokia Corporation and/or its subsidiary(-ies).
+* All rights reserved.
+* This component and the accompanying materials are made available
+* under the terms of "Eclipse Public License v1.0"
+* which accompanies this distribution, and is available
+* at the URL "http://www.eclipse.org/legal/epl-v10.html".
+*
+* Initial Contributors:
+* Nokia Corporation - initial contribution.
+*
+* Contributors:
+*
+* Description:  
+*
+*/
+
+
+#ifndef HNXMLMODELCACHE_H_
+#define HNXMLMODELCACHE_H_
+
+#include <e32base.h>
+#include <e32hashtab.h>
+#include <xmlengdom.h>
+#include <bautils.h>
+
+
+/**
+ * Suites cache.
+ * 
+ * This class is designed to support caching xml documents which contain
+ * suites definitions.
+ * 
+ * The cache is directlty used by the xml model provider (CHnXmlModelProvider)
+ * and is transparent for other data model's classes.
+ * 
+ * The cache has a maksimum capacity which is equal to KXmlModelCacheMaxLength.
+ * The cache works similarily to a shift register. When the maksimum size of
+ * the cache is exceeded then the last element in the cache is removed.
+ * On contrary, most often used xml documents are moved to the beggining
+ * of the cache.
+ * 
+ * @since S60 5.0
+ * @ingroup group_hnmetadatamodel
+ */
+NONSHARABLE_CLASS( CHnXmlModelCache ) : public CBase
+    {
+
+private:
+    
+    /**
+     * Default constructor.
+     * 
+     * @since S60 5.0
+     */
+    CHnXmlModelCache();
+    
+    /**
+     * Standard second phase constructor.
+     * 
+     * @since S60 5.0
+     */
+    void ConstructL();
+    
+    /**
+     * Removes a xml document from the cache if the size of the cache
+     * is exceeded.
+     * 
+     * @since S60 5.0
+     */
+    void RemoveUnused();
+    
+    /**
+     * Moves the xml document (identified by a given name) to the top of the
+     * cache.
+     * 
+     * @param aSuiteName A name of the xml document to be moved to the top
+     *                   of the cache.
+     * @since S60 5.0
+     */
+    void MoveToTopL( const TDesC & aSuiteName );
+
+public:
+    
+    /**
+     * Two-phase constructor.
+     * 
+     * @since S60 5.0
+     */
+    static CHnXmlModelCache* NewLC();
+    
+    /**
+     * Two-phase constructor.
+     * 
+     * 
+     */
+    static CHnXmlModelCache* NewL();
+    
+    /**
+     * Adds a new xml document into the cache.
+     * @param aSuiteName A name of the suite.
+     * @param aDocument A xml document to be added to the cache.
+     * 
+     * @since S60 5.0
+     */
+    TInt AddL( const TDesC& aSuiteName, RXmlEngDocument& aDocument );
+    
+    /**
+     * Checks if the xml document is stored in the cache.
+     * 
+     * @param aSuiteName The name of the suite to be checked.
+     * @return ETrue if a suite of a given name is stored in the cache,
+     *         otherwise - EFalse.
+     *         
+     * @since S60 5.0
+     */
+    TBool IsCachedL( const TDesC& aSuiteName );
+    
+    /**
+     * Gets a xml document by a given name.
+     * 
+     * @param aSuiteName The name corresponding to the xml document to be
+     *                   retrieved from the cache.
+     * @param aDocument The reference to the xml document.
+     * 
+     * @since S60 5.0
+     */
+    void GetL( const TDesC& aSuiteName, RXmlEngDocument& aDocument );
+    
+    /**
+     * Resets the cache - removes all stored xml documents.
+     * 
+     * @since S60 5.0
+     */
+    void Reset();
+    
+    /**
+     * Standard C++ virtual destructor.
+     * 
+     * @since S60 5.0
+     */
+    virtual ~CHnXmlModelCache();
+
+private:
+    
+    /**
+     * The hash map storing pairs: name of the suite, corresponding xml
+     * document.
+     * 
+     * @since S60 5.0
+     */
+    RHashMap< HBufC*, RXmlEngDocument > iDocuments;
+    
+    /**
+     * An auxilliary array storing the order of the xml document
+     * in the cache.
+     * 
+     * @since S60 5.0
+     */
+    RPointerArray< HBufC > iOrder;
+    
+    };
+
+#endif /*HNXMLMODELCACHE_H_*/