gov.nasa.worldwind.data
Class CachedDataRaster

java.lang.Object
  gov.nasa.worldwind.avlist.AVListImpl
      gov.nasa.worldwind.data.CachedDataRaster

All Implemented Interfaces:

AVList, DataRaster, Disposable

public class CachedDataRaster
extends AVListImpl
implements DataRaster

The CachedDataRaster is used to hold data raster's source and metadata, while the actual data raster may not be loaded in to the memory. This is mostly used together with a memory caches. CachedDataRaster actually implements all interfaces of the DataRaster, and acts as a proxy, that loads a real data raster only when it is actually needed.

Nested Class Summary

protected static class

CachedDataRaster.ErrorHandlerMode

Field Summary

protected MemoryCache.CacheListener	cacheListener
protected DataRasterReader	dataReader
protected Object	dataSource
protected MemoryCache	rasterCache
protected Object	rasterRetrievalLock
protected Object	rasterUsageLock
protected String[]	requiredKeys

Constructor Summary

CachedDataRaster(Object source, AVList params, DataRasterReader reader, MemoryCache cache)
Create a cached data raster.

Method Summary

protected void	assembleMetadata(Object source, AVList params, DataRasterReader reader)
protected String	composeExceptionReason(Throwable t)
void	dispose() Disposes of any internal resources allocated by the object.
protected static void	disposeRasters(DataRaster[] rasters)
void	drawOnTo(DataRaster canvas) Copies this raster into a specified raster.
DataRasterReader	getDataRasterReader()
protected DataRaster[]	getDataRasters()
Object	getDataSource()
int	getHeight() Returns the raster's height in raster units.
AVList	getMetadata()
AVList	getParams()
protected String[]	getRequiredKeysList()
Sector	getSector() Returns the region covered be the data.
protected long	getSizeInBytes(DataRaster[] rasters)
DataRaster	getSubRaster(AVList params) Returns a portion of this raster as another raster.
DataRaster	getSubRaster(int width, int height, Sector sector, AVList params) Returns a portion of this raster as another raster.
protected static long	getTotalUsedMemory()
int	getWidth() Returns the raster's width in raster units.
protected boolean	hasRequiredMetadata(AVList params, CachedDataRaster.ErrorHandlerMode throwException) Validates if params (AVList) has all required keys.
protected void	releaseMemory()

Methods inherited from class gov.nasa.worldwind.avlist.AVListImpl

addPropertyChangeListener, addPropertyChangeListener, clearList, copy, firePropertyChange, firePropertyChange, getBooleanValue, getBooleanValue, getChangeSupport, getDoubleValue, getDoubleValue, getEntries, getIntegerValue, getIntegerValue, getLongValue, getLongValue, getRestorableStateForAVPair, getStringValue, getStringValue, getStringValue, getValue, getValues, hasKey, removeKey, removePropertyChangeListener, removePropertyChangeListener, setValue, setValues

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface gov.nasa.worldwind.avlist.AVList

addPropertyChangeListener, addPropertyChangeListener, clearList, copy, firePropertyChange, firePropertyChange, getEntries, getStringValue, getValue, getValues, hasKey, removeKey, removePropertyChangeListener, removePropertyChangeListener, setValue, setValues

Field Detail

cacheListener

protected MemoryCache.CacheListener cacheListener

dataReader

protected DataRasterReader dataReader

dataSource

protected Object dataSource

rasterCache

protected MemoryCache rasterCache

rasterRetrievalLock

protected final Object rasterRetrievalLock

rasterUsageLock

protected final Object rasterUsageLock

requiredKeys

protected String[] requiredKeys

Constructor Detail

CachedDataRaster

public CachedDataRaster(Object source,
                        AVList params,
                        DataRasterReader reader,
                        MemoryCache cache)
                 throws IOException,
                        IllegalArgumentException

Create a cached data raster.

Parameters:

source - the location of the local file, expressed as either a String path, a File, or a file URL.

params - metadata as AVList, it is expected to next parameters: AVKey.WIDTH, AVKey.HEIGHT, AVKey.SECTOR, AVKey.PIXEL_FORMAT.

If any of these keys is missing, there will be an attempt made to retrieve missign metadata from the source using the reader.

reader - A reference to a DataRasterReader instance

cache - A reference to a MemoryCache instance

Throws:

IOException - thrown if there is an error to read metadata from the source

IllegalArgumentException - thrown when a source or a reader are null

Method Detail

assembleMetadata

protected void assembleMetadata(Object source,
                                AVList params,
                                DataRasterReader reader)
                         throws IOException,
                                IllegalArgumentException

Throws:

IOException

IllegalArgumentException

composeExceptionReason

protected String composeExceptionReason(Throwable t)

dispose

public void dispose()

Description copied from interface: Disposable

Disposes of any internal resources allocated by the object.

Specified by:

dispose in interface Disposable

disposeRasters

protected static void disposeRasters(DataRaster[] rasters)

drawOnTo

public void drawOnTo(DataRaster canvas)

Description copied from interface: DataRaster

Copies this raster into a specified raster.

Specified by:

drawOnTo in interface DataRaster

Parameters:

canvas - - the raster to copy into.

getDataRasterReader

public DataRasterReader getDataRasterReader()

getDataRasters

protected DataRaster[] getDataRasters()
                               throws IOException,
                                      WWRuntimeException

Throws:

IOException

WWRuntimeException

getDataSource

public Object getDataSource()

getHeight

public int getHeight()

Description copied from interface: DataRaster

Returns the raster's height in raster units.

Specified by:

getHeight in interface DataRaster

Returns:

the raster's height in raster units.

getMetadata

public AVList getMetadata()

getParams

public AVList getParams()

getRequiredKeysList

protected String[] getRequiredKeysList()

getSector

public Sector getSector()

Description copied from interface: DataRaster

Returns the region covered be the data.

Specified by:

getSector in interface DataRaster

Returns:

a sector indicating the region covered by the raster.

getSizeInBytes

protected long getSizeInBytes(DataRaster[] rasters)

getSubRaster

public DataRaster getSubRaster(AVList params)

Description copied from interface: DataRaster

Returns a portion of this raster as another raster. Input values are the desired width and height of the return sub-raster, and the sector to copy from this raster to the sub-raster. The returned raster conforms to EPSG:4326 even if this raster does not.

Specified by:

getSubRaster in interface DataRaster

Parameters:

params - a list of parameters that specify the width, height and sector of the region to return. Specify these values using AVKey.WIDTH, AVKey.HEIGHT and AVKey.SECTOR.

Returns:

the requested raster, or null if the raster could not be created.

getSubRaster

public DataRaster getSubRaster(int width,
                               int height,
                               Sector sector,
                               AVList params)

Description copied from interface: DataRaster

Returns a portion of this raster as another raster. The returned raster conforms to EPSG:4326 even if this raster does not.

Specified by:

getSubRaster in interface DataRaster

Parameters:

width - the width to make the returned sub-raster.

height - the height to make the returned sub-raster.

sector - the sector to copy.

params - a list of parameters that specify the width, height and sector of the region to return. Specify these values using AVKey.WIDTH, AVKey.HEIGHT and AVKey.SECTOR.

Returns:

the requested raster, or null if the raster could not be created.

getTotalUsedMemory

protected static long getTotalUsedMemory()

getWidth

public int getWidth()

Description copied from interface: DataRaster

Returns the raster's width in raster units.

Specified by:

getWidth in interface DataRaster

Returns:

the raster's width in raster units.

hasRequiredMetadata

protected boolean hasRequiredMetadata(AVList params,
                                      CachedDataRaster.ErrorHandlerMode throwException)
                               throws IllegalArgumentException

Validates if params (AVList) has all required keys.

Parameters:

params - AVList of key/value pairs

throwException - specifies weather to throw exception when a key/value is missing, or just return false.

Returns:

TRUE, if all required keys are present in the params list, or both params and required keys are empty, otherwise returns FALSE (if throwException is false)

Throws:

IllegalArgumentException - If a key/value is missing and throwException is set to TRUE

releaseMemory

protected void releaseMemory()