Package com.luciad.earth.tileset.util

Class TLcdEarthMemoryCachingTileSet

java.lang.Object
com.luciad.earth.tileset.util.ALcdEarthTileSetWrapper
com.luciad.earth.tileset.util.TLcdEarthMemoryCachingTileSet
All Implemented Interfaces:
ILcdEarthTileSet, ILcdBounded, ILcdDisposable, AutoCloseable
public class TLcdEarthMemoryCachingTileSet extends ALcdEarthTileSetWrapper
A tileset wrapper that caches tiles in memory.

This class is thread-safe if the delegate tileset is also thread-safe.

Since:
9.1

  • Constructor Details

    • TLcdEarthMemoryCachingTileSet

      public TLcdEarthMemoryCachingTileSet(ILcdEarthTileSet aDelegate, int aNumCachedTiles)
      Creates a new memory caching tileset with the given parameters.
      Parameters:
      aDelegate - the delegate that produces the tiles.
      aNumCachedTiles - the maximum number of cached tiles.

  • Method Details

    • produceTile

      public void produceTile(ILcdEarthTileSetCoverage aCoverage, int aLevel, long aTileX, long aTileY, ILcdGeoReference aGeoReference, TLcdEarthTileFormat aFormat, TLcdEarthTileOperationMode aMode, ILcdEarthTileSetCallback aCallback, Object aContext)
      Description copied from interface: ILcdEarthTileSet
      Produces the requested tile, and invoke the supplied callback when done. The resulting tile is passed to the call back's tileAvailable() method. If the tile cannot be produced for some reason, the method tileNotAvailable() should be called instead.

      If the tileset supports it and aMode is TLcdEarthTileOperationMode.PREFER_ASYNCHRONOUS, the tile request may be executed asynchronously. However, the callback must be invoked at some point in time, unless the cancelTile() method is used to cancel the tile request before it is executed. If aMode is TLcdEarthTileOperationMode.FORCE_SYNCHRONOUS, the request must be executed synchronously and the callback must be invoked before produceTile() returns.

      Tiles may be requested in reference systems other than the native geo reference of the underlying data, provided that the isGeoReferenceSupported() method returns true for the requested reference. If this is not the case, the tileset should call tileNotAvailable(). If the tileset calls tileAvailable(), the geo reference of the resulting tile must be equal to aGeoReference, and the tile's bounds must likewise be expressed in this reference.

      Similarly, tiles may be requested in different data formats, as described by TLcdEarthTileFormat. The format determines the type of the data object that will be contained in the requested tile. To check if a format is supported, use isFormatSupported(). If the specified format is not supported, the tileset should call tileNotAvailable().

      The context parameter may be used to pass application-specific data into the tileset. If it is not needed, its value may be null.

      Specified by:
      produceTile in interface ILcdEarthTileSet
      Overrides:
      produceTile in class ALcdEarthTileSetWrapper
      Parameters:
      aCoverage - the coverage from which the tile is requested
      aLevel - the level from which the tile is requested
      aTileX - the column index of the requested tile
      aTileY - the row index of the requested tile
      aGeoReference - the reference system in which the tile should be returned
      aFormat - the desired format of the tile's data
      aMode - controls the synchronous or asynchronous behaviour of the tileset
      aCallback - will be invoked when the tile is available to be used
      aContext - application-specific data to be used by the tileset, if any

    • produceTile

      public ALcdEarthTile produceTile(ILcdEarthTileSetCoverage aCoverage, int aLevel, long aX, long aY, ILcdGeoReference aGeoReference, TLcdEarthTileFormat aFormat, Object aContext) throws IOException
      Description copied from interface: ILcdEarthTileSet
      Gets a tile from the repository.
      Specified by:
      produceTile in interface ILcdEarthTileSet
      Overrides:
      produceTile in class ALcdEarthTileSetWrapper
      Parameters:
      aCoverage - the coverage from which to query a tile
      aLevel - the detail level for which to query a tile
      aX - the column index at which to query a tile
      aY - the row index at which to query a tile
      aGeoReference - the georeference of the requested tile
      aFormat - the format of the requested tile
      aContext - application-specific data to be used by the tileset, if any
      Returns:
      the requested tile, or null if the repository does not contain this tile
      Throws:
      IOException - if the tile cannot be produced

    • getTileFromCache

      public ALcdEarthTile getTileFromCache(ILcdEarthTileSetCoverage aCoverage, int aLevel, long aTileX, long aTileY, ILcdGeoReference aGeoReference, TLcdEarthTileFormat aFormat, Object aContext)
      Retrieves a tile from the cache. No attempt will be made to produce the tile if it is not available in the cache.
      Parameters:
      aCoverage - the coverage
      aLevel - the tile level
      aTileX - the tile x coordinate
      aTileY - the tile y coordinate
      aGeoReference - the tile reference
      aFormat - the tile format
      aContext - the context
      Returns:
      the requested tile or null if it is not present in the cache.

    • containsTile

      public boolean containsTile(ILcdEarthTileSetCoverage aCoverage, int aLevel, long aX, long aY, Object aContext)
      Description copied from interface: ILcdEarthTileSet
      Returns true if the repository contains the specified tile.
      Specified by:
      containsTile in interface ILcdEarthTileSet
      Overrides:
      containsTile in class ALcdEarthTileSetWrapper
      Parameters:
      aCoverage - the coverage from which to query a tile
      aLevel - the detail level for which to query a tile
      aX - the column index at which to query a tile
      aY - the row index at which to query a tile
      aContext - application-specific data to be used by the tileset, if any
      Returns:
      true if the repository contains the requested tile

    • updateTile

      public void updateTile(ALcdEarthTile aTile, TLcdEarthTileOperationMode aMode, ILcdEarthTileSetCallback aCallback, Object aContext)
      Updates the tile and the version cached in memory.
      Specified by:
      updateTile in interface ILcdEarthTileSet
      Overrides:
      updateTile in class ALcdEarthTileSetWrapper
      Parameters:
      aTile - tile to check
      aMode - controls the synchronous or asynchronous behaviour of the tileset
      aCallback - will be invoked when the tile is available to be used
      aContext - application-specific data to be used by the tileset, if any

    • updateTile

      public ALcdEarthTile updateTile(ALcdEarthTile aEarthTile, Object aContext) throws IOException
      Updates the tile and the version cached in memory.
      Specified by:
      updateTile in interface ILcdEarthTileSet
      Overrides:
      updateTile in class ALcdEarthTileSetWrapper
      Parameters:
      aEarthTile - the tile to check
      aContext - application-specific data to be used by the tileset, if any
      Returns:
      the tile itself or a new, updated version
      Throws:
      IOException - if the tile cannot be updated

    • isCacheable

      protected boolean isCacheable(ALcdEarthTile aTile, Object aContext)
      Returns whether the tile should be cached or not. The default implementation always returns true.
      Parameters:
      aTile - the tile
      aContext - the context of the tile production
      Returns:
      true if the given tile should be cached, false otherwise

    • cancelTile

      public void cancelTile(int aLevel, long aTileX, long aTileY, ILcdEarthTileSetCoverage aCoverage, ILcdGeoReference aGeoReference, TLcdEarthTileFormat aFormat, ILcdEarthTileSetCallback aCallback, Object aContext)
      Description copied from class: ALcdEarthTileSetWrapper
      This method should be overridden if the produceTile and/or updateTile is overridden and the new implementation calls the implementation of this class using different parameters than passed to it.

      If the produceTile is overridden as 

       super.produceTile( myCoverage, aLevel, aTileX, aTileY, aGeoReference, aFormat, aMode, new MyTileSetCallback( aCallback ), aContext );
      this method should be overridden as 
       super.cancelTile( aLevel, aTileX, aTileY, myCoverage, aGeoReference, aFormat, new MyTileSetCallback( aCallback ), aContext );
      where MyTileSetCallback instances with the same delegate callback are equal.
      Specified by:
      cancelTile in interface ILcdEarthTileSet
      Overrides:
      cancelTile in class ALcdEarthTileSetWrapper
      Parameters:
      aLevel - the level from which the tile is requested
      aTileX - the column index of the requested tile
      aTileY - the row index of the requested tile
      aCoverage - the coverage from which the tile is requested
      aGeoReference - the reference system in which the tile is requested
      aFormat - the format in which the tile is requested
      aCallback - would be invoked when the tile would have been available to be used
      aContext - application-specific data to be used by the tileset, if any

    • dispose

      public void dispose()
      Description copied from interface: ILcdEarthTileSet
      This method releases all resources held by the repository, such as file locks, threads or server connections.
      Specified by:
      dispose in interface ILcdDisposable
      Specified by:
      dispose in interface ILcdEarthTileSet
      Overrides:
      dispose in class ALcdEarthTileSetWrapper

    • clearCache

      public void clearCache()
      Clears the tile cache.

    • getCacheSize

      public int getCacheSize()
      Returns the maximum number of the cached tiles.
      Returns:
      the size of the cache.

    • setCacheSize

      public void setCacheSize(int aSize)
      Sets the maximum number of cached tiles. If the cache size is decreased some tiles will no longer be cached, otherwise all previously cached tiles will still be cached.
      Parameters:
      aSize - the new cache size.