org.apache.lucene.search
Class CachingSpanFilter

java.lang.Object
  org.apache.lucene.search.Filter
      org.apache.lucene.search.SpanFilter
          org.apache.lucene.search.CachingSpanFilter

All Implemented Interfaces:

Serializable

public class CachingSpanFilter
extends SpanFilter

Wraps another SpanFilter'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

CachingSpanFilter(SpanFilter filter)
New deletions always result in a cache miss, by default (CachingWrapperFilter.DeletesMode.RECACHE.

CachingSpanFilter(SpanFilter filter, CachingWrapperFilter.DeletesMode deletesMode)

Method Summary

SpanFilterResult	bitSpans(IndexReader reader) Returns a SpanFilterResult with true for documents which should be permitted in search results, and false for those that should not and Spans for where the true docs match.
boolean	equals(Object o)
DocIdSet	getDocIdSet(IndexReader reader) Creates a DocIdSet enumerating the documents that should be permitted in search results.
int	hashCode()
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

CachingSpanFilter

public CachingSpanFilter(SpanFilter filter)

New deletions always result in a cache miss, by default (CachingWrapperFilter.DeletesMode.RECACHE.

Parameters:

filter - Filter to cache results of

CachingSpanFilter

public CachingSpanFilter(SpanFilter filter,
                         CachingWrapperFilter.DeletesMode deletesMode)

Parameters:

filter - Filter to cache results of

deletesMode - See CachingWrapperFilter.DeletesMode

Method Detail

getDocIdSet

public DocIdSet getDocIdSet(IndexReader reader)
                     throws IOException

Description copied from class: Filter

Creates a DocIdSet enumerating the documents that should be permitted in search results. NOTE: null can be returned if no documents are accepted by this Filter.

Note: This method will be called once per segment in the index during searching. The returned DocIdSet must refer to document IDs for that segment, not for the top-level reader.

Specified by:

getDocIdSet in class Filter

Parameters:

reader - a IndexReader instance opened on the index currently searched on. Note, it is likely that the provided reader does not represent the whole underlying index i.e. if the index has more than one segment the given reader only represents a single segment.

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

bitSpans

public SpanFilterResult bitSpans(IndexReader reader)
                          throws IOException

Description copied from class: SpanFilter

Returns a SpanFilterResult with true for documents which should be permitted in search results, and false for those that should not and Spans for where the true docs match.

Specified by:

bitSpans in class SpanFilter

Parameters:

reader - The IndexReader to load position and DocIdSet information from

Returns:

A SpanFilterResult

Throws:

IOException - if there was an issue accessing the necessary information

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