Package org.apache.sis.storage.aggregate

Class ConcatenatedGridCoverage.Loader

java.lang.Object

org.apache.sis.storage.aggregate.ConcatenatedGridCoverage.Loader

Enclosing class:

ConcatenatedGridCoverage

private static final class ConcatenatedGridCoverage.Loader
extends Object

The class in charge of loading and caching grid coverages. The same loader may be shared by many ConcatenatedGridCoverage instances. Loaders are immutable (except for the cache) and thread-safe.

Field Summary

Fields

Modifier and Type	Field	Description
private final Cache<Integer,GridCoverage>	coverages	Cache of GridCoverage instances.
(package private) final int[]	deferred	Whether loading of grid coverages should be deferred to rendering time.
private final GridGeometry	domain	The domain to request when reading a coverage from the resource.
private final int[]	ranges	The sample dimensions to request when loading slices from the #resources.

Constructor Summary

Constructors

Constructor	Description
Loader(int[] deferred, GridGeometry domain, int[] ranges)	Creates a new loader.

Method Summary

Modifier and Type	Method	Description
(package private) final GridCoverage	getOrLoad(Integer key, GridCoverageResource source)	Returns the coverage if available in the cache, or load it immediately otherwise.

Methods inherited from class java.lang.Object

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

Field Details

deferred

final int[] deferred

Whether loading of grid coverages should be deferred to rendering time. This is a bit set packed as long values. A bit value of 1 means that the coverages at the corresponding index should be loaded from the slices at same index only when first needed.

See Also:

• ConcatenatedGridResource.deferredLoading
• ConcatenatedGridCoverage.isDeferred(int)

domain

private final GridGeometry domain

The domain to request when reading a coverage from the resource.

ranges

private final int[] ranges

The sample dimensions to request when loading slices from the #resources.

coverages

private final Cache<Integer,GridCoverage> coverages

Cache of GridCoverage instances. Keys are index in the ConcatenatedGridCoverage.slices array.

Constructor Details

Loader

Loader(int[] deferred,
 GridGeometry domain,
 int[] ranges)

Creates a new loader.

Parameters:

deferred - whether loading of grid coverages should be deferred to rendering time.

domain - grid geometry to request when loading data.

ranges - bands to request when loading coverages.

Method Details

getOrLoad

final GridCoverage getOrLoad(Integer key,
 GridCoverageResource source)
                      throws DataStoreException

Returns the coverage if available in the cache, or load it immediately otherwise. This method shall be invoked only when isDeferred(key) == true. This method can be invoked from any thread.

Parameters:

key - index of the GridCoverageResource in the ConcatenatedGridCoverage.slices array.

source - value of slices[key], used only if data need to be loaded.

Returns:

the coverage at the given index.

Throws:

NullPointerException - if no GridCoverageResource are expected to exist.

DataStoreException - if an error occurred while loading data from the resource.