Package org.hibernate.search.engine.common.tree.impl

Class TreeFilter

java.lang.Object

org.hibernate.search.engine.common.tree.impl.TreeFilter

public class TreeFilter
extends Object

A tree filter, responsible for deciding which parts of a (potentially cyclic) graph will be retained as a tree, e.g. in an index schema.

A tree filter that accepts everything is created at the root of tree-like mapping structures (e.g. a Pojo mapping). Then, each time specific nesting features (e.g. index embedding with @IndexedEmbedded) are used, another filter is created with the constraints defined through that feature (e.g. @IndexedEmbedded(includePaths = ...)).

Filter usage in index schemas

A tree filter is asked to provide advice about whether to trim down the index schema in two cases:

• When a field is added by a bridge, the filter decides whether to include this field or not through its isPathIncluded(String) method
• When a nested filter (e.g. @IndexedEmbedded) is requested, a new filter is created through the compose(MappingElement, String, TreeFilterDefinition, TreeFilterPathTracker, BiFunction) method, which may return an empty optional, meaning that the nested filter excludes every path.

Filter properties

A tree filter decides whether to include a path or not according to its two main properties:

• the depth filter
• the path filter

The path filter, as its name suggests, define which paths should be explicitly included or excluded by this filter.

The depth filter defines how paths that are not explicitly included or excluded by the path filter should be treated:

• as long as the remaining depth is unlimited (null) or strictly positive, paths are included by default
• as soon as the remaining depth is zero or negative, paths are excluded by default

Filter composition

Composed filters are created whenever a nested filter (e.g. @IndexedEmbedded) is encountered. A composed filter will always enforce the restrictions of its parent filter, plus some added restrictions depending on the properties of the nested filter.

For more information about how filters are composed, see compose(MappingElement, String, TreeFilterDefinition, TreeFilterPathTracker, BiFunction).

Method Summary

Modifier and Type	Method	Description
TreeFilter	compose(MappingElement mappingElement, String relativePrefix, TreeFilterDefinition definition, TreeFilterPathTracker pathTracker, BiFunction<MappingElement,String,SearchException> cyclicRecursionExceptionFactory)
boolean	isEveryPathExcluded()
boolean	isPathIncluded(String relativePath)
static TreeFilter	root()
String	toString()

Methods inherited from class java.lang.Object

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

Method Detail

root

public static TreeFilter root()

toString

public String toString()

Overrides:

toString in class Object

isPathIncluded

public boolean isPathIncluded(String relativePath)

isEveryPathExcluded

public boolean isEveryPathExcluded()

compose

public TreeFilter compose(MappingElement mappingElement,
                          String relativePrefix,
                          TreeFilterDefinition definition,
                          TreeFilterPathTracker pathTracker,
                          BiFunction<MappingElement,String,SearchException> cyclicRecursionExceptionFactory)