org.apache.lucene.search
Class CachingWrapperFilter

java.lang.Object
  org.apache.lucene.search.Filter
      org.apache.lucene.search.CachingWrapperFilter

All Implemented Interfaces:

Serializable

public class CachingWrapperFilter
extends Filter

Wraps another filter's result and caches it. The purpose is to allow filters to simply filter, and then wrap with this class to add caching.

See Also:

Serialized Form

Constructor Summary

CachingWrapperFilter(Filter filter)

Method Summary

protected DocIdSet	docIdSetToCache(DocIdSet docIdSet, IndexReader reader) Provide the DocIdSet to be cached, using the DocIdSet provided by the wrapped Filter.
boolean	equals(Object o)
DocIdSet	getDocIdSet(IndexReader reader)
int	hashCode()
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

CachingWrapperFilter

public CachingWrapperFilter(Filter filter)

Parameters:

filter - Filter to cache results of

Method Detail

docIdSetToCache

protected DocIdSet docIdSetToCache(DocIdSet docIdSet,
                                   IndexReader reader)
                            throws IOException

Provide the DocIdSet to be cached, using the DocIdSet provided by the wrapped Filter.

This implementation returns the given DocIdSet, if DocIdSet.isCacheable() returns true, else it copies the DocIdSetIterator into an OpenBitSetDISI.

Throws:

IOException

getDocIdSet

public DocIdSet getDocIdSet(IndexReader reader)
                     throws IOException

Specified by:

getDocIdSet in class Filter

Returns:

a DocIdSet that provides the documents which should be permitted or prohibited in search results. NOTE: null can be returned if no documents will be accepted by this Filter.

Throws:

IOException

See Also:

DocIdBitSet

toString

public String toString()

Overrides:

toString in class Object

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object