Package org.apache.lucene.monitor

Class QueryTree

java.lang.Object

org.apache.lucene.monitor.QueryTree

public abstract class QueryTree
extends Object

A representation of a node in a query tree

Queries are analyzed and converted into an abstract tree, consisting of conjunction and disjunction nodes, and leaf nodes containing terms.

Terms may be collected from a node, which will use the weights of its sub-nodes to determine which paths are followed. The path may be changed by calling advancePhase(double)

Constructor Summary

Constructors

Constructor	Description
QueryTree()

Method Summary

Modifier and Type	Method	Description
abstract boolean	advancePhase(double minWeight)	Find the next-most highly-weighted path below this node
static QueryTree	anyTerm(String reason)	Returns a leaf node that will match any document
abstract void	collectTerms(BiConsumer<String,BytesRef> termCollector)	Collect terms from the most highly-weighted path below this node
static QueryTree	conjunction(List<Function<TermWeightor,QueryTree>> children, TermWeightor weightor)	Returns a conjunction of a set of child nodes
static QueryTree	disjunction(List<Function<TermWeightor,QueryTree>> children, TermWeightor weightor)	Returns a disjunction of a set of child nodes
protected String	space(int width)	Returns a string of width spaces
static QueryTree	term(String field, BytesRef term, double weight)	Returns a leaf node for a particular term and weight
static QueryTree	term(Term term, double weight)	Returns a leaf node for a particular term and weight
static QueryTree	term(Term term, TermWeightor weightor)	Returns a leaf node for a particular term
String	toString()
abstract String	toString(int depth)	Returns a string representation of the node
abstract double	weight()	The weight of this node

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

QueryTree

public QueryTree()

Method Detail

weight

public abstract double weight()

The weight of this node

collectTerms

public abstract void collectTerms(BiConsumer<String,BytesRef> termCollector)

Collect terms from the most highly-weighted path below this node

advancePhase

public abstract boolean advancePhase(double minWeight)

Find the next-most highly-weighted path below this node

Parameters:

minWeight - do not advance if the next path has a weight below this value

Returns:

false if there are no more paths above the minimum weight

toString

public abstract String toString(int depth)

Returns a string representation of the node

Parameters:

depth - the current depth of this node in the overall query tree

toString

public String toString()

Overrides:

toString in class Object

space

protected String space(int width)

Returns a string of width spaces

term

public static QueryTree term(Term term,
                             TermWeightor weightor)

Returns a leaf node for a particular term

term

public static QueryTree term(Term term,
                             double weight)

Returns a leaf node for a particular term and weight

The weight must be greater than 0

term

public static QueryTree term(String field,
                             BytesRef term,
                             double weight)

Returns a leaf node for a particular term and weight

The weight must be greater than 0

anyTerm

public static QueryTree anyTerm(String reason)

Returns a leaf node that will match any document

conjunction

public static QueryTree conjunction(List<Function<TermWeightor,QueryTree>> children,
                                    TermWeightor weightor)

Returns a conjunction of a set of child nodes

disjunction

public static QueryTree disjunction(List<Function<TermWeightor,QueryTree>> children,
                                    TermWeightor weightor)

Returns a disjunction of a set of child nodes