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/*
* Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
* or more contributor license agreements. Licensed under the Elastic License
* 2.0 and the Server Side Public License, v 1; you may not use this file except
* in compliance with, at your election, the Elastic License 2.0 or the Server
* Side Public License, v 1.
*/
package org.elasticsearch.search.aggregations.support;
/**
*
* This package holds shared code for the aggregations framework, especially around dealing with values.
*
*
* Key Classes
*
* {@link org.elasticsearch.search.aggregations.support.ValuesSource} and its subclasses
*
* These are thin wrappers which provide a unified interface to different ways of getting input data (e.g. DocValues from Lucene, or script
* output). A class hierarchy defines the type of values returned by the source. The top level sub-classes define type-specific behavior,
* such as {@link org.elasticsearch.search.aggregations.support.ValuesSource.Numeric#isFloatingPoint()}. Second level subclasses are
* then specialized based on where they read values from, e.g. script or field cases. There are also adapter classes like
* {@link org.elasticsearch.search.aggregations.bucket.geogrid.CellIdSource} which do run-time conversion from one type to another, often
* dependent on a user specified parameter (precision in that case).
*
*
* {@link org.elasticsearch.search.aggregations.support.ValuesSourceRegistry}
*
* ValuesSourceRegistry stores the mappings for what types are supported by what aggregations. It is configured at startup, when
* {@link org.elasticsearch.search.SearchModule} is configuring aggregations. It shouldn't be necessary to access the registry in most
* cases, but you can get a read copy from
* {@link org.elasticsearch.search.aggregations.support.AggregationContext#getValuesSourceRegistry()} if necessary.
*
*
* {@link org.elasticsearch.search.aggregations.support.ValuesSourceType}
*
* ValuesSourceTypes are the quantum of support in the aggregations framework, and provide a common language between fields and
* aggregations. Fields which support aggregation set a ValuesSourceType on their {@link org.elasticsearch.index.fielddata.IndexFieldData}
* implementations, and aggregations register what types they support via one of the
* {@link org.elasticsearch.search.aggregations.support.ValuesSourceRegistry.Builder#register} methods. The VaulesSourceType itself holds
* information on how to work with values of that type, including methods for creating
* {@link org.elasticsearch.search.aggregations.support.ValuesSource} instances and {@link org.elasticsearch.search.DocValueFormat}
* instances.
*
*
* {@link org.elasticsearch.search.aggregations.support.ValuesSourceConfig}
*
* There are two things going on in ValuesSourceConfig. First, there is a collection of static factory methods to build valid configs for
* different situations. {@link org.elasticsearch.search.aggregations.support.ValuesSourceAggregationBuilder#resolveConfig} has a good
* default for what to call here and generally aggregations shouldn't need to deviate from that.
*
*
*
* Once properly constructed, the ValuesSourceConfig provides access to the ValuesSource instance, as well as related information like the
* formatter. Aggregations are free to use this information as needed, such as Max and Min which inspect the field context to see if they
* can apply an optimization.
*
*
* Classes we are trying to phase out
* {@link org.elasticsearch.search.aggregations.support.ValueType}
*
* This class is primarily used for parsing user type hints, and is deprecated for new use. Work is ongoing to remove it from existing
* code.
*
*
*/