org.sindice.siren.search.node

Class TwigQuery

java.lang.Object

org.apache.lucene.search.Query

org.sindice.siren.search.node.NodeQuery

org.sindice.siren.search.node.TwigQuery

All Implemented Interfaces:

Cloneable

Direct Known Subclasses:

TupleQuery

public class TwigQuery
extends NodeQuery

A NodeQuery that matches a boolean combination of Ancestor-Descendant and Parent-Child node queries.

Code taken from BooleanQuery and adapted for the Siren use case.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	TwigQuery.EmptyRootQuery An empty root query is used to create twig query in which the root query is not specified.
protected class	TwigQuery.TwigWeight Expert: the Weight for TwigQuery, used to normalize, score and explain these queries.

Field Summary

Fields

Modifier and Type	Field and Description
protected ArrayList<NodeBooleanClause>	clauses

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

ancestor, levelConstraint, lowerBound, upperBound

Constructor Summary

Constructors

Constructor and Description
TwigQuery() Constructs an empty twig query with a default level of 1.
TwigQuery(int rootLevel) Constructs an empty twig query at a given level

Method Summary

Methods

Modifier and Type	Method and Description
void	addChild(NodeQuery query, NodeBooleanClause.Occur occur) Adds a child clause to the twig query.
protected void	addClause(NodeBooleanClause clause) Adds a clause to a twig query.
void	addDescendant(int nodeLevel, NodeQuery query, NodeBooleanClause.Occur occur) Adds a descendant clause to the twig query.
void	addRoot(NodeQuery root) Adds a root query.
List<NodeBooleanClause>	clauses() Returns the list of ancestor clauses in this query.
org.apache.lucene.search.Query	clone()
org.apache.lucene.search.Weight	createWeight(org.apache.lucene.search.IndexSearcher searcher)
boolean	equals(Object o) Returns true iff o is equal to this.
NodeBooleanClause[]	getClauses() Returns the set of ancestor clauses in this query.
static int	getMaxClauseCount() Return the maximum number of clauses permitted, 1024 by default.
NodeQuery	getRoot() Return the root of this query
int	hashCode()
Iterator<NodeBooleanClause>	iterator() Returns an iterator on the clauses in this query.
org.apache.lucene.search.Query	rewrite(org.apache.lucene.index.IndexReader reader)
protected void	setAncestorPointer(NodeQuery ancestor) Expert: Add a pointer to the node query ancestor
void	setLevelConstraint(int levelConstraint) Set a constraint on the node's level
static void	setMaxClauseCount(int maxClauseCount) Set the maximum number of clauses permitted per TwigQuery.
void	setNodeConstraint(int lowerBound, int upperBound) Set an index interval constraint for a node.
String	toString(String field)

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

getDocsNodesAndPositionsEnum, getLevelConstraint, getNodeConstraint, setNodeConstraint

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

extractTerms, getBoost, setBoost, toString

Methods inherited from class java.lang.Object

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

Field Detail

clauses

protected ArrayList<NodeBooleanClause> clauses

Constructor Detail

TwigQuery

public TwigQuery(int rootLevel)

Constructs an empty twig query at a given level

TwigQuery

public TwigQuery()

Constructs an empty twig query with a default level of 1.

Method Detail

getMaxClauseCount

public static int getMaxClauseCount()

Return the maximum number of clauses permitted, 1024 by default. Attempts to add more than the permitted number of clauses cause NodeBooleanQuery.TooManyClauses to be thrown.

See Also:

setMaxClauseCount(int)

setMaxClauseCount

public static void setMaxClauseCount(int maxClauseCount)

Set the maximum number of clauses permitted per TwigQuery. Default value is 1024.

addRoot

public void addRoot(NodeQuery root)

Adds a root query.

Overwrite the level and node constraints of the root query with the currently defined level and node constraints of the twig query.

addClause

protected void addClause(NodeBooleanClause clause)

Adds a clause to a twig query.

Throws:

NodeBooleanQuery.TooManyClauses - if the new number of clauses exceeds the maximum clause number

See Also:

getMaxClauseCount()

addChild

public void addChild(NodeQuery query,
            NodeBooleanClause.Occur occur)

Adds a child clause to the twig query.

Throws:

NodeBooleanQuery.TooManyClauses - if the new number of clauses exceeds the maximum clause number

See Also:

getMaxClauseCount()

addDescendant

public void addDescendant(int nodeLevel,
                 NodeQuery query,
                 NodeBooleanClause.Occur occur)

Adds a descendant clause to the twig query. The node level of the descendant is relative to the twig level.

Throws:

NodeBooleanQuery.TooManyClauses - if the new number of clauses exceeds the maximum clause number

See Also:

getMaxClauseCount()

setAncestorPointer

protected void setAncestorPointer(NodeQuery ancestor)

Description copied from class: NodeQuery

Expert: Add a pointer to the node query ancestor

The pointer to node query ancestor is used to retrieve node constraints from ancestors.

Overrides:

setAncestorPointer in class NodeQuery

setNodeConstraint

public void setNodeConstraint(int lowerBound,
                     int upperBound)

Description copied from class: NodeQuery

Set an index interval constraint for a node. These constraints are inclusives.

Overrides:

setNodeConstraint in class NodeQuery

setLevelConstraint

public void setLevelConstraint(int levelConstraint)

Description copied from class: NodeQuery

Set a constraint on the node's level

Given that the root of the tree (level 0) is the document id, the node level constraint ranges from 1 to Integer.MAX_VALUE. A node level constraint of 0 will always return false.

Overrides:

setLevelConstraint in class NodeQuery

getRoot

public NodeQuery getRoot()

Return the root of this query

getClauses

public NodeBooleanClause[] getClauses()

Returns the set of ancestor clauses in this query.

clauses

public List<NodeBooleanClause> clauses()

Returns the list of ancestor clauses in this query.

iterator

public final Iterator<NodeBooleanClause> iterator()

Returns an iterator on the clauses in this query. It implements the Iterable interface to make it possible to do:

for (SirenBooleanClause clause : booleanQuery) {}

createWeight

public org.apache.lucene.search.Weight createWeight(org.apache.lucene.search.IndexSearcher searcher)
                                             throws IOException

Overrides:

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

Throws:

IOException

rewrite

public org.apache.lucene.search.Query rewrite(org.apache.lucene.index.IndexReader reader)
                                       throws IOException

Overrides:

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

Throws:

IOException

clone

public org.apache.lucene.search.Query clone()

Overrides:

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

toString

public String toString(String field)

Specified by:

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

equals

public boolean equals(Object o)

Returns true iff o is equal to this.

Overrides:

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

hashCode

public int hashCode()

Overrides:

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