org.sindice.siren.search.node

Class NodeQuery

java.lang.Object

org.apache.lucene.search.Query

org.sindice.siren.search.node.NodeQuery

All Implemented Interfaces:

Cloneable

Direct Known Subclasses:

NodeBooleanQuery, NodePrimitiveQuery, TwigQuery, TwigQuery.EmptyRootQuery

public abstract class NodeQuery
extends org.apache.lucene.search.Query

Abstract class for the SIREn's node queries

This class provides an interface to manage node constraints. When a DocsNodesAndPositionsEnum is requested using the method getDocsNodesAndPositionsEnum(DocsAndPositionsEnum), it traverses all the NodeQuery ancestor of the current NodeQuery and creates a ConstraintStack. Given the constraint stack, the appropriate ConstrainedNodesEnum is created and returned.

Field Summary

Fields

Modifier and Type	Field and Description
protected NodeQuery	ancestor The pointer to direct node query ancestor
protected int	levelConstraint The node level constraint.
protected int	lowerBound The lower and upper bound of the interval constraint over the node indexes.
protected int	upperBound The lower and upper bound of the interval constraint over the node indexes.

Constructor Summary

Constructors

Constructor and Description
NodeQuery()

Method Summary

Methods

Modifier and Type	Method and Description
protected DocsNodesAndPositionsEnum	getDocsNodesAndPositionsEnum(org.apache.lucene.index.DocsAndPositionsEnum docsEnum) Provides a DocsNodesAndPositionsEnum given a DocsAndPositionsEnum.
int	getLevelConstraint()
int[]	getNodeConstraint()
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
void	setNodeConstraint(int index) Set the node index constraint.
void	setNodeConstraint(int lowerBound, int upperBound) Set an index interval constraint for a node.

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

clone, createWeight, equals, extractTerms, getBoost, hashCode, rewrite, setBoost, toString, toString

Methods inherited from class java.lang.Object

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

Field Detail

levelConstraint

protected int levelConstraint

The node level constraint.

Set to sentinel value -1 by default.

lowerBound

protected int lowerBound

The lower and upper bound of the interval constraint over the node indexes.

Set to sentinel value -1 by default.

upperBound

protected int upperBound

The lower and upper bound of the interval constraint over the node indexes.

Set to sentinel value -1 by default.

ancestor

protected NodeQuery ancestor

The pointer to direct node query ancestor

Constructor Detail

NodeQuery

public NodeQuery()

Method Detail

setLevelConstraint

public void setLevelConstraint(int levelConstraint)

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.

getLevelConstraint

public int getLevelConstraint()

setNodeConstraint

public void setNodeConstraint(int lowerBound,
                     int upperBound)

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

setNodeConstraint

public void setNodeConstraint(int index)

Set the node index constraint.

getNodeConstraint

public int[] getNodeConstraint()

setAncestorPointer

protected void setAncestorPointer(NodeQuery ancestor)

Expert: Add a pointer to the node query ancestor

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

getDocsNodesAndPositionsEnum

protected DocsNodesAndPositionsEnum getDocsNodesAndPositionsEnum(org.apache.lucene.index.DocsAndPositionsEnum docsEnum)

Provides a DocsNodesAndPositionsEnum given a DocsAndPositionsEnum. If a set of constraints is applied, it automatically wraps the DocsNodesAndPositionsEnum into a ConstrainedNodesEnum.