org.apache.druid.query.search

Class SearchQueryQueryToolChest

java.lang.Object

org.apache.druid.query.QueryToolChest<Result<SearchResultValue>,SearchQuery>

org.apache.druid.query.search.SearchQueryQueryToolChest

public class SearchQueryQueryToolChest
extends QueryToolChest<Result<SearchResultValue>,SearchQuery>

Constructor Summary

Constructors

Constructor and Description
SearchQueryQueryToolChest(SearchQueryConfig config)
SearchQueryQueryToolChest(SearchQueryConfig config, SearchQueryMetricsFactory queryMetricsFactory)

Method Summary

Modifier and Type	Method and Description
BinaryOperator<Result<SearchResultValue>>	createMergeFn(Query<Result<SearchResultValue>> query) Creates a merge function that is used to merge intermediate aggregates from historicals in broker.
Comparator<Result<SearchResultValue>>	createResultComparator(Query<Result<SearchResultValue>> query) Creates an ordering comparator that is used to order results.
CacheStrategy<Result<SearchResultValue>,Object,SearchQuery>	getCacheStrategy(SearchQuery query) Returns a CacheStrategy to be used to load data into the cache and remove it from the cache.
com.fasterxml.jackson.core.type.TypeReference<Result<SearchResultValue>>	getResultTypeReference() Returns a TypeReference object that is just passed through to Jackson in order to deserialize the results of this type of query.
SearchQueryMetrics	makeMetrics(SearchQuery query) Creates a QueryMetrics object that is used to generate metrics for this specific query type.
com.google.common.base.Function<Result<SearchResultValue>,Result<SearchResultValue>>	makePreComputeManipulatorFn(SearchQuery query, MetricManipulationFn fn) Creates a Function that can take in a ResultType and return a new ResultType having applied the MetricManipulatorFn to each of the metrics.
QueryRunner<Result<SearchResultValue>>	preMergeQueryDecoration(QueryRunner<Result<SearchResultValue>> runner) Wraps a QueryRunner.

Methods inherited from class org.apache.druid.query.QueryToolChest

canPerformSubquery, decorateObjectMapper, filterSegments, getBaseResultType, getBySegmentResultType, makePostComputeManipulatorFn, mergeResults, postMergeQueryDecoration, resultArraySignature, resultsAsArrays

Methods inherited from class java.lang.Object

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

Constructor Detail

SearchQueryQueryToolChest

public SearchQueryQueryToolChest(SearchQueryConfig config)

SearchQueryQueryToolChest

@Inject
public SearchQueryQueryToolChest(SearchQueryConfig config,
                                         SearchQueryMetricsFactory queryMetricsFactory)

Method Detail

createMergeFn

public BinaryOperator<Result<SearchResultValue>> createMergeFn(Query<Result<SearchResultValue>> query)

Description copied from class: QueryToolChest

Creates a merge function that is used to merge intermediate aggregates from historicals in broker. This merge function is used in the default ResultMergeQueryRunner provided by QueryToolChest.mergeResults(QueryRunner) and also used in ParallelMergeCombiningSequence by 'CachingClusteredClient' if it does not return null. Returning null from this function means that a query does not support result merging, at least via the mechanisms that utilize this function.

Overrides:

createMergeFn in class QueryToolChest<Result<SearchResultValue>,SearchQuery>

createResultComparator

public Comparator<Result<SearchResultValue>> createResultComparator(Query<Result<SearchResultValue>> query)

Description copied from class: QueryToolChest

Creates an ordering comparator that is used to order results. This comparator is used in the default ResultMergeQueryRunner provided by QueryToolChest.mergeResults(QueryRunner)

Overrides:

createResultComparator in class QueryToolChest<Result<SearchResultValue>,SearchQuery>

makeMetrics

public SearchQueryMetrics makeMetrics(SearchQuery query)

Description copied from class: QueryToolChest

Creates a QueryMetrics object that is used to generate metrics for this specific query type. This exists to allow for query-specific dimensions and metrics. That is, the ToolChest is expected to set some meaningful dimensions for metrics given this query type. Examples might be the topN threshold for a TopN query or the number of dimensions included for a groupBy query.

QueryToolChests for query types in core (druid-processing) and public extensions (belonging to the Druid source tree) should use delegate this method to GenericQueryMetricsFactory.makeMetrics(Query) on an injected instance of GenericQueryMetricsFactory, as long as they don't need to emit custom dimensions and/or metrics.

If some custom dimensions and/or metrics should be emitted for a query type, a plan described in "Making subinterfaces of QueryMetrics" section in QueryMetrics's class-level Javadocs should be followed.

One way or another, this method should ensure that QueryMetrics.query(Query) is called with the given query passed on the created QueryMetrics object before returning.

Specified by:

makeMetrics in class QueryToolChest<Result<SearchResultValue>,SearchQuery>

Parameters:

query - The query that is being processed

Returns:

A QueryMetrics that can be used to make metrics for the provided query

makePreComputeManipulatorFn

public com.google.common.base.Function<Result<SearchResultValue>,Result<SearchResultValue>> makePreComputeManipulatorFn(SearchQuery query,
                                                                                                                        MetricManipulationFn fn)

Description copied from class: QueryToolChest

Creates a Function that can take in a ResultType and return a new ResultType having applied the MetricManipulatorFn to each of the metrics.

This exists because the QueryToolChest is the only thing that understands the internal serialization format of ResultType, so it's primary responsibility is to "decompose" that structure and apply the given function to all metrics.

This function is called very early in the processing pipeline on the Broker.

Specified by:

makePreComputeManipulatorFn in class QueryToolChest<Result<SearchResultValue>,SearchQuery>

Parameters:

query - The Query that is currently being processed

fn - The function that should be applied to all metrics in the results

Returns:

A function that will apply the provided fn to all metrics in the input ResultType object

getResultTypeReference

public com.fasterxml.jackson.core.type.TypeReference<Result<SearchResultValue>> getResultTypeReference()

Description copied from class: QueryToolChest

Returns a TypeReference object that is just passed through to Jackson in order to deserialize the results of this type of query.

Specified by:

getResultTypeReference in class QueryToolChest<Result<SearchResultValue>,SearchQuery>

Returns:

A TypeReference to indicate to Jackson what type of data will exist for this query

getCacheStrategy

public CacheStrategy<Result<SearchResultValue>,Object,SearchQuery> getCacheStrategy(SearchQuery query)

Description copied from class: QueryToolChest

Returns a CacheStrategy to be used to load data into the cache and remove it from the cache.

This is optional. If it returns null, caching is effectively disabled for the query.

Overrides:

getCacheStrategy in class QueryToolChest<Result<SearchResultValue>,SearchQuery>

Parameters:

query - The query whose results might be cached

Returns:

A CacheStrategy that can be used to populate and read from the Cache

preMergeQueryDecoration

public QueryRunner<Result<SearchResultValue>> preMergeQueryDecoration(QueryRunner<Result<SearchResultValue>> runner)

Description copied from class: QueryToolChest

Wraps a QueryRunner. The input QueryRunner is the QueryRunner as it exists *before* being passed to mergeResults().

In fact, the return value of this method is always passed to mergeResults, so it is equivalent to just implement this functionality as extra decoration on the QueryRunner during mergeResults().

In the interests of potentially simplifying these interfaces, the recommendation is to actually not override this method and instead apply anything that might be needed here in the mergeResults() call.

Overrides:

preMergeQueryDecoration in class QueryToolChest<Result<SearchResultValue>,SearchQuery>

Parameters:

runner - The runner to be wrapped

Returns:

The wrapped runner