org.apache.lucene.spatial.prefix

Class WithinPrefixTreeFilter

java.lang.Object

org.apache.lucene.search.Filter

org.apache.lucene.spatial.prefix.AbstractPrefixTreeFilter

org.apache.lucene.spatial.prefix.AbstractVisitingPrefixTreeFilter

org.apache.lucene.spatial.prefix.WithinPrefixTreeFilter

public class WithinPrefixTreeFilter
extends AbstractVisitingPrefixTreeFilter

Finds docs where its indexed shape is WITHIN the query shape. It works by looking at cells outside of the query shape to ensure documents there are excluded. By default, it will examine all cells, and it's fairly slow. If you know that the indexed shapes are never comprised of multiple disjoint parts (which also means it is not multi-valued), then you can pass SpatialPrefixTree.getDistanceForLevel(maxLevels) as the queryBuffer constructor parameter to minimally look this distance beyond the query shape's edge. Even if the indexed shapes are sometimes comprised of multiple disjoint parts, you might want to use this option with a large buffer as a faster approximation with minimal false-positives.

WARNING: This API is experimental and might change in incompatible ways in the next release.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.lucene.spatial.prefix.AbstractVisitingPrefixTreeFilter

AbstractVisitingPrefixTreeFilter.VisitorTemplate, AbstractVisitingPrefixTreeFilter.VNode

Nested classes/interfaces inherited from class org.apache.lucene.spatial.prefix.AbstractPrefixTreeFilter

AbstractPrefixTreeFilter.BaseTermsEnumTraverser

Field Summary

Fields inherited from class org.apache.lucene.spatial.prefix.AbstractVisitingPrefixTreeFilter

prefixGridScanLevel

Fields inherited from class org.apache.lucene.spatial.prefix.AbstractPrefixTreeFilter

detailLevel, fieldName, grid, queryShape

Constructor Summary

Constructors

Constructor and Description
WithinPrefixTreeFilter(com.spatial4j.core.shape.Shape queryShape, String fieldName, SpatialPrefixTree grid, int detailLevel, int prefixGridScanLevel, double queryBuffer) See AbstractVisitingPrefixTreeFilter.AbstractVisitingPrefixTreeFilter(com.spatial4j.core.shape.Shape, String, org.apache.lucene.spatial.prefix.tree.SpatialPrefixTree, int, int).

Method Summary

Methods

Modifier and Type	Method and Description
protected com.spatial4j.core.shape.Shape	bufferShape(com.spatial4j.core.shape.Shape shape, double distErr) Returns a new shape that is larger than shape by at distErr.
DocIdSet	getDocIdSet(LeafReaderContext context, Bits acceptDocs)

Methods inherited from class org.apache.lucene.spatial.prefix.AbstractVisitingPrefixTreeFilter

equals, hashCode

Methods inherited from class java.lang.Object

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

Constructor Detail

WithinPrefixTreeFilter

public WithinPrefixTreeFilter(com.spatial4j.core.shape.Shape queryShape,
                      String fieldName,
                      SpatialPrefixTree grid,
                      int detailLevel,
                      int prefixGridScanLevel,
                      double queryBuffer)

See AbstractVisitingPrefixTreeFilter.AbstractVisitingPrefixTreeFilter(com.spatial4j.core.shape.Shape, String, org.apache.lucene.spatial.prefix.tree.SpatialPrefixTree, int, int). queryBuffer is the (minimum) distance beyond the query shape edge where non-matching documents are looked for so they can be excluded. If -1 is used then the whole world is examined (a good default for correctness).

Method Detail

bufferShape

protected com.spatial4j.core.shape.Shape bufferShape(com.spatial4j.core.shape.Shape shape,
                                         double distErr)

Returns a new shape that is larger than shape by at distErr.

getDocIdSet

public DocIdSet getDocIdSet(LeafReaderContext context,
                   Bits acceptDocs)
                     throws IOException

Specified by:

getDocIdSet in class Filter

Throws:

IOException