Package mondrian.rolap.agg

Class SegmentCacheManager.CompositeSegmentCache

java.lang.Object

mondrian.rolap.agg.SegmentCacheManager.CompositeSegmentCache

All Implemented Interfaces:

SegmentCache

Enclosing class:

SegmentCacheManager

static class SegmentCacheManager.CompositeSegmentCache
extends Object
implements SegmentCache

Makes a collection of SegmentCacheWorker objects (each of which is backed by a SegmentCache appear to be a SegmentCache.

For most operations, it is easier to operate on a single cache. It is usually clear whether operations should quit when finding the first match, or to operate on all workers. (For example, remove(mondrian.spi.SegmentHeader) tries to remove the segment header from all workers, and returns whether it was removed from any of them.) This class just does what seems most typical. If you want another behavior for a particular operation, operate on the workers directly.

Nested Class Summary

Nested classes/interfaces inherited from interface mondrian.spi.SegmentCache

SegmentCache.SegmentCacheInjector, SegmentCache.SegmentCacheListener

Field Summary

Fields

Modifier and Type	Field	Description
(package private) List<SegmentCacheWorker>	workers

Constructor Summary

Constructors

Constructor	Description
CompositeSegmentCache(List<SegmentCacheWorker> workers)

Method Summary

Modifier and Type	Method	Description
void	addListener(SegmentCache.SegmentCacheListener listener)	Adds a listener to this segment cache implementation.
SegmentBody	get(SegmentHeader header)	Returns a SegmentBody once the cache has returned any results, or null if no segment corresponding to the header could be found.
List<SegmentHeader>	getSegmentHeaders()	Returns a list of all segments present in the cache.
boolean	put(SegmentHeader header, SegmentBody body)	Stores a segment data in the cache.
boolean	remove(SegmentHeader header)	Removes a segment from the cache.
void	removeListener(SegmentCache.SegmentCacheListener listener)	Unregisters a listener from this segment cache implementation.
boolean	supportsRichIndex()	Tells Mondrian whether this segment cache uses the SegmentHeader objects as an index, thus preserving them in a serialized state, or if it uses its identification number only.
void	tearDown()	Tear down and clean up the cache.

Methods inherited from class java.lang.Object

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

Field Detail

workers

final List<SegmentCacheWorker> workers

Constructor Detail

CompositeSegmentCache

public CompositeSegmentCache(List<SegmentCacheWorker> workers)

Method Detail

get

public SegmentBody get(SegmentHeader header)

Description copied from interface: SegmentCache

Returns a SegmentBody once the cache has returned any results, or null if no segment corresponding to the header could be found.

Cache implementations are at liberty to 'forget' segments. Therefore it is allowable for this method to return null at any time

Specified by:

get in interface SegmentCache

Parameters:

header - The header of the segment to find. Consider this as a key.

Returns:

A SegmentBody, or null if no corresponding segment could be found in cache.

getSegmentHeaders

public List<SegmentHeader> getSegmentHeaders()

Description copied from interface: SegmentCache

Returns a list of all segments present in the cache.

Specified by:

getSegmentHeaders in interface SegmentCache

Returns:

A List of segment headers describing the contents of the cache.

put

public boolean put(SegmentHeader header,
                   SegmentBody body)

Description copied from interface: SegmentCache

Stores a segment data in the cache.

Specified by:

put in interface SegmentCache

Parameters:

header - The header of the segment.

body - The segment body to cache.

Returns:

Whether the cache write succeeded

remove

public boolean remove(SegmentHeader header)

Description copied from interface: SegmentCache

Removes a segment from the cache.

Specified by:

remove in interface SegmentCache

Parameters:

header - The header of the segment we want to remove.

Returns:

True if the segment was found and removed, false otherwise.

tearDown

public void tearDown()

Description copied from interface: SegmentCache

Tear down and clean up the cache.

Specified by:

tearDown in interface SegmentCache

addListener

public void addListener(SegmentCache.SegmentCacheListener listener)

Description copied from interface: SegmentCache

Adds a listener to this segment cache implementation. The listener will get notified via SegmentCache.SegmentCacheListener.SegmentCacheEvent instances.

Specified by:

addListener in interface SegmentCache

Parameters:

listener - The listener to attach to this cache.

removeListener

public void removeListener(SegmentCache.SegmentCacheListener listener)

Description copied from interface: SegmentCache

Unregisters a listener from this segment cache implementation.

Specified by:

removeListener in interface SegmentCache

Parameters:

listener - The listener to remove.

supportsRichIndex

public boolean supportsRichIndex()

Description copied from interface: SegmentCache

Tells Mondrian whether this segment cache uses the SegmentHeader objects as an index, thus preserving them in a serialized state, or if it uses its identification number only.

Not using a rich index prevents Mondrian from doing partial cache invalidation.

It is assumed that this method returns fairly quickly, and for a given cache always returns the same value.

Specified by:

supportsRichIndex in interface SegmentCache

Returns:

Whether this segment cache preserves headers in serialized state