aif_map_chart_cache.h

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/*! \file
  \brief  The AIFMapChartLayerCache class.

  \par Copyright Information

  Copyright (c) 2008 The DiSTI Corporation.<br>
  11486 Corporate Blvd; Suite 190<br>
  Orlando, Florida 32817<br>
  USA<br>
  <br>
  All rights reserved.<br>

  This Software contains proprietary trade secrets of DiSTI and may not be
reproduced, in whole or part, in any form, or by any means of electronic,
mechanical, or otherwise, without the written permission of DiSTI.  Said
permission may be derived through the purchase of applicable DiSTI product
licenses which detail the distribution rights of this content and any
Derivative Works based on this or other copyrighted DiSTI Software.

  NO WARRANTY. THE SOFTWARE IS PROVIDED "AS-IS," WITHOUT WARRANTY OF ANY KIND,
AND ANY USE OF THIS SOFTWARE PRODUCT IS AT YOUR OWN RISK. TO THE MAXIMUM EXTENT
PERMITTED BY APPLICABLE LAW, DISTI AND ITS SUPPLIERS DISCLAIM ALL WARRANTIES
AND CONDITIONS, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
IMPLIED WARRANTIES AND CONDITIONS OF MERCHANTABILITY AND/OR FITNESS FOR A
PARTICULAR PURPOSE, TITLE, AND NON-INFRINGEMENT, WITH REGARD TO THE SOFTWARE.

  LIMITATION OF LIABILITY. TO THE MAXIMUM EXTENT PERMITTED BY APPLICABLE LAW,
IN NO EVENT SHALL DISTI OR ITS SUPPLIERS BE LIABLE FOR ANY SPECIAL, INCIDENTAL,
INDIRECT, OR CONSEQUENTIAL DAMAGES WHATSOEVER (INCLUDING, WITHOUT LIMITATION,
DAMAGES FOR LOSS OF BUSINESS PROFITS, BUSINESS INTERRUPTION, LOSS OF BUSINESS
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  The aforementioned terms and restrictions are governed by the laws of the
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*/
#ifndef _AIF_MAP_CHART_CACHE_H
#define _AIF_MAP_CHART_CACHE_H

#include "gls_map_chart_data_source.h"
#include <set>

namespace disti
{
class AifMapChartCell;

/** helper class for caching cells between layer changes */
class AIFMapChartLayerCache
{
public:
    /** Ctor */
    AIFMapChartLayerCache( void ) { _memorySizeMeg = 30u; };

    /** Dtor - releases all cached cells */
    virtual ~AIFMapChartLayerCache()
    {
        // release all cached cells
        const unsigned int entryCount = _layerCache.Count();
        for( unsigned int i = 0u; i < entryCount; ++i )
        {
            _layerCache[ i ]->ReleaseCachedCells();
        }
        _layerCache.Clear();
    }

    /** update the given layer with the latest cells from GetCellList
      * \param resolution The resolution of the given cell list
      * \param cellList latest cells from GetCellList for the layer
      */
    virtual void UpdateLayer( const double resolution, const MapChartCellList& cellList );

    /** Get the memory storage amount (Megabytes)
      * \return max number of layers to cache ( 0u if caching is disabled )
      */
    virtual float GetCacheSize( void ) const
    {
        return ( _memorySizeMeg );
    }

    /** \return The amount of cache used. Calls CurrentSizeMeg() */
    virtual float GetCacheUsed()
    {
        return CurrentSizeMeg();
    }

    /** Set the memory storage amount (megabytes)
      * \param memSize Megabytes of the cache
      */
    virtual void SetCacheSize( const float memSize );

protected:
    /** entry for cache info for one layer */
    class LayerCacheEntry
    {
    public:
        /** ctor
          * \param resolution the resolution for this entry
          * \param cellList most recent cell list from GetCellList call
          */
        LayerCacheEntry( const double resolution, const MapChartCellList& cellList );

        /** dtor - releases any cached cells */
        ~LayerCacheEntry()
        {
            ReleaseCachedCells();
        }

        /** Get the layer ID associated with this entry
          * \return layer ID associated with this entry
          */
        double GetResolution( void ) const { return ( _resolution ); }

        /** Release any cached cells */
        void ReleaseCachedCells( void );

        /** Merges cells into the collection of cells */
        void UpdateLatestCells( const MapChartCellList& cellList );
        void UpdateLatestCellsReplace( const MapChartCellList& cellList );

        void ReCalcSize();

        /** Size in megabytes of this cell cache */
        float SizeMeg()
        {
            return _cellsCacheSizeBytes / 1048576.0f;
        }

    protected:
        const double _resolution; /**< resolution associated with this entry */
        unsigned int _cellsCacheSizeBytes;

        typedef std::set<AifMapChartCell*> CachedCells;
        CachedCells                        _cells; /**<  The cached cells */
    };

    // Implementation of the current usage
    virtual float CurrentSizeMeg();

private:
    /**< cache of LayerCacheEntry, last entry in array is always the
    * current layer */
    DynamicArray<LayerCacheEntry*> _layerCache;

    /** Megabyte Memory allocation for AIF Cache */
    float _memorySizeMeg;
};
} // namespace disti

#endif