com.openharbor.beck.map
Class DefaultMapperPool

java.lang.Object
  com.openharbor.beck.map.DefaultMapperPool

All Implemented Interfaces:

MapFromXML.Source, MapToXML.Source

public class DefaultMapperPool

extends java.lang.Object

implements MapFromXML.Source, MapToXML.Source

A source of mappers that's thread-safe and can track changes in the underlying configuration.

Constructor Summary

DefaultMapperPool(java.lang.ClassLoader loader, java.lang.String resourceName)
Configure the mappers from a Configuration mapped from a PollableResource.

DefaultMapperPool(Configuration configuration)
Configure the mappers from the given Configuration.

Method Summary

MapFromXML	allocateMapFromXML() Obtain a current mapper.
DefaultMapper	allocateMapper()
MapToXML	allocateMapToXML() Obtain a current mapper.
protected DefaultMapper	newMapper(Configuration configuration)
void	pollSoon() Check for a change in the configuration next time allocateMapFromXML() is called, regardless of the currently acceptable staleness.
void	releaseMapFromXML(MapFromXML toRelease) Make a mapper available for re-use.
void	releaseMapper(DefaultMapper toRelease)
void	releaseMapToXML(MapToXML toRelease) Make a mapper available for use by other threads.
protected void	removeDeadKeys() Remove entries from configuration2mappers whose key has been garbage collected.

Methods inherited from class java.lang.Object

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

Constructor Detail

DefaultMapperPool

public DefaultMapperPool(Configuration configuration)

Configure the mappers from the given Configuration.

DefaultMapperPool

public DefaultMapperPool(java.lang.ClassLoader loader,
                         java.lang.String resourceName)

Configure the mappers from a Configuration mapped from a PollableResource. After a change to the resource is detected by polling, allocated mappers will have a correspondingly changed Configuration.

Method Detail

allocateMapFromXML

public MapFromXML allocateMapFromXML()
                              throws java.lang.Exception

Description copied from interface: MapFromXML.Source

Obtain a current mapper. For best performance, the caller should pass the allocated mapper to MapFromXML.Source.releaseMapFromXML(com.openharbor.beck.map.MapFromXML) after the caller has done using it. For best performance, this method should return the same object repeatedly, switching to a new object only when necessary (e.g. when the old object is intolerably stale).

Specified by:

allocateMapFromXML in interface MapFromXML.Source

Throws:

java.lang.Exception

allocateMapToXML

public MapToXML allocateMapToXML()
                          throws java.lang.Exception

Description copied from interface: MapToXML.Source

Obtain a current mapper. For best performance, the caller should pass the allocated mapper to MapToXML.Source.releaseMapToXML(com.openharbor.beck.map.MapToXML) after the caller has done using it. For best performance, this method should return the same object repeatedly, switching to a new object only when necessary (e.g. when the old object is intolerably stale).

Specified by:

allocateMapToXML in interface MapToXML.Source

Throws:

java.lang.Exception

releaseMapFromXML

public void releaseMapFromXML(MapFromXML toRelease)

Description copied from interface: MapFromXML.Source

Make a mapper available for re-use. The caller must not use this mapper subsequently (unless the same mapper is returned from another call to MapFromXML.Source.allocateMapFromXML()). This Source may allocate the mapper to another thread, which might result in erroneous concurrent use of the mapper by both threads if a previous releaser cheats.

Specified by:

releaseMapFromXML in interface MapFromXML.Source

releaseMapToXML

public void releaseMapToXML(MapToXML toRelease)

Description copied from interface: MapToXML.Source

Make a mapper available for use by other threads. The caller must not use this mapper subsequently (unless the same mapper is returned from another call to MapToXML.Source.allocateMapToXML()). This source may allocate the mapper to another thread, which might result in erroneous concurrent use of the mapper by both threads.

Specified by:

releaseMapToXML in interface MapToXML.Source

pollSoon

public void pollSoon()

Description copied from interface: MapFromXML.Source

Check for a change in the configuration next time MapFromXML.Source.allocateMapFromXML() is called, regardless of the currently acceptable staleness.

Specified by:

pollSoon in interface MapFromXML.Source

allocateMapper

public DefaultMapper allocateMapper()
                             throws java.lang.Exception

Throws:

java.lang.Exception

newMapper

protected DefaultMapper newMapper(Configuration configuration)
                           throws java.lang.Exception

Throws:

java.lang.Exception

releaseMapper

public void releaseMapper(DefaultMapper toRelease)

removeDeadKeys

protected void removeDeadKeys()

Remove entries from configuration2mappers whose key has been garbage collected. The caller must synchronize on configuration2mappers; this method mutates it, but does not synchronize on it.