org.sindice.siren.search.node

Class NodeAutomatonQuery

java.lang.Object

org.apache.lucene.search.Query

org.sindice.siren.search.node.NodeQuery

org.sindice.siren.search.node.NodePrimitiveQuery

org.sindice.siren.search.node.MultiNodeTermQuery

org.sindice.siren.search.node.NodeAutomatonQuery

All Implemented Interfaces:

Cloneable

Direct Known Subclasses:

NodeRegexpQuery, NodeWildcardQuery

public class NodeAutomatonQuery
extends MultiNodeTermQuery

A MultiNodeTermQuery that will match terms against a finite-state machine.

This query will match documents that contain terms accepted by a given finite-state machine. The automaton can be constructed with the org.apache.lucene.util.automaton API. Alternatively, it can be created from a regular expression with RegexpQuery or from the standard Lucene wildcard syntax with NodeWildcardQuery.

When the query is executed, it will create an equivalent DFA of the finite-state machine, and will enumerate the term dictionary in an intelligent way to reduce the number of comparisons. For example: the regular expression of [dl]og? will make approximately four comparisons: do, dog, lo, and log.

Nested Class Summary

Nested classes/interfaces inherited from class org.sindice.siren.search.node.MultiNodeTermQuery

MultiNodeTermQuery.RewriteMethod

Field Summary

Fields

Modifier and Type	Field and Description
protected org.apache.lucene.util.automaton.Automaton	automaton the automaton to match index terms against
protected org.apache.lucene.util.automaton.CompiledAutomaton	compiled
protected org.apache.lucene.index.Term	term term containing the field, and possibly some pattern structure

Fields inherited from class org.sindice.siren.search.node.MultiNodeTermQuery

CONSTANT_SCORE_AUTO_REWRITE_DEFAULT, CONSTANT_SCORE_BOOLEAN_QUERY_REWRITE, CONSTANT_SCORE_FILTER_REWRITE, field, rewriteMethod, SCORING_BOOLEAN_QUERY_REWRITE

Fields inherited from class org.sindice.siren.search.node.NodePrimitiveQuery

datatype

Fields inherited from class org.sindice.siren.search.node.NodeQuery

ancestor, levelConstraint, lowerBound, upperBound

Constructor Summary

Constructors

Constructor and Description
NodeAutomatonQuery(org.apache.lucene.index.Term term, org.apache.lucene.util.automaton.Automaton automaton) Create a new AutomatonQuery from an Automaton.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	equals(Object obj)
protected org.apache.lucene.index.TermsEnum	getTermsEnum(org.apache.lucene.index.Terms terms, org.apache.lucene.util.AttributeSource atts) Construct the enumeration to be used, expanding the pattern term.
int	hashCode()
String	toString(String field)

Methods inherited from class org.sindice.siren.search.node.MultiNodeTermQuery

getField, getRewriteMethod, getTermsEnum, rewrite, setRewriteMethod

Methods inherited from class org.sindice.siren.search.node.NodePrimitiveQuery

setDatatype, wrapToStringWithDatatype

Methods inherited from class org.sindice.siren.search.node.NodeQuery

getDocsNodesAndPositionsEnum, getLevelConstraint, getNodeConstraint, setAncestorPointer, setLevelConstraint, setNodeConstraint, setNodeConstraint

Methods inherited from class org.apache.lucene.search.Query

clone, createWeight, extractTerms, getBoost, setBoost, toString

Methods inherited from class java.lang.Object

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

Field Detail

automaton

protected final org.apache.lucene.util.automaton.Automaton automaton

the automaton to match index terms against

compiled

protected final org.apache.lucene.util.automaton.CompiledAutomaton compiled

term

protected final org.apache.lucene.index.Term term

term containing the field, and possibly some pattern structure

Constructor Detail

NodeAutomatonQuery

public NodeAutomatonQuery(org.apache.lucene.index.Term term,
                  org.apache.lucene.util.automaton.Automaton automaton)

Create a new AutomatonQuery from an Automaton.

Parameters:

term - Term containing field and possibly some pattern structure. The term text is ignored.

automaton - Automaton to run, terms that are accepted are considered a match.

Method Detail

getTermsEnum

protected org.apache.lucene.index.TermsEnum getTermsEnum(org.apache.lucene.index.Terms terms,
                                             org.apache.lucene.util.AttributeSource atts)
                                                  throws IOException

Description copied from class: MultiNodeTermQuery

Construct the enumeration to be used, expanding the pattern term. This method should only be called if the field exists (ie, implementations can assume the field does exist). This method should not return null (should instead return TermsEnum.EMPTY if no terms match). The TermsEnum must already be positioned to the first matching term. The given AttributeSource is passed by the MultiNodeTermQuery.RewriteMethod to provide attributes, the rewrite method uses to inform about e.g. maximum competitive boosts. This is currently only used by TopNodeTermsRewrite

Specified by:

getTermsEnum in class MultiNodeTermQuery

Throws:

IOException

hashCode

public int hashCode()

Overrides:

hashCode in class MultiNodeTermQuery

equals

public boolean equals(Object obj)

Overrides:

equals in class MultiNodeTermQuery

toString

public String toString(String field)

Specified by:

toString in class org.apache.lucene.search.Query