com.netflix.hollow.core.index

Class HollowHashIndex

java.lang.Object

com.netflix.hollow.core.index.HollowHashIndex

public class HollowHashIndex
extends java.lang.Object

A HollowHashIndex is used for indexing non-primary-key data. This type of index can map multiple keys to a single matching record, and/or multiple records to a single key.

The field definitions in a hash key may be hierarchical (traverse multiple record types) via dot-notation. For example, the field definition actors.element.actorId may be used to traverse a child LIST or SET type record referenced by the field actors, each elements contained therein, and finally each actors actorId field.

Constructor Summary

Constructors

Constructor and Description
HollowHashIndex(HollowReadStateEngine stateEngine, java.lang.String type, java.lang.String selectField, java.lang.String... matchFields) Define a HollowHashIndex.

Method Summary

Methods

Modifier and Type	Method and Description
HollowHashIndexResult	findMatches(java.lang.Object... query) Query the index.

Methods inherited from class java.lang.Object

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

Constructor Detail

HollowHashIndex

public HollowHashIndex(HollowReadStateEngine stateEngine,
               java.lang.String type,
               java.lang.String selectField,
               java.lang.String... matchFields)

Define a HollowHashIndex.

Parameters:

stateEngine - The state engine to index

type - The query starts with the specified type

selectField - The query will select records at this field (specify "" to select the specified type). The selectField may span collection elements and/or map keys or values, which can result in multiple matches per record of the specified start type.

matchFields - The query will match on the specified match fields. The match fields may span collection elements and/or map keys or values.

Method Detail

findMatches

public HollowHashIndexResult findMatches(java.lang.Object... query)

Query the index. The returned HollowHashIndexResult will be null if no matches were found. Otherwise, may be used to gather the matched ordinals.