org.apache.druid.segment.filter

Class Filters

java.lang.Object

org.apache.druid.segment.filter.Filters

public class Filters
extends Object

Constructor Summary

Constructors

Constructor and Description
Filters()

Method Summary

Modifier and Type	Method and Description
static Filter	and(List<Filter> filters) Create a filter representing an AND relationship across a list of filters.
static boolean	checkFilterTuningUseIndex(String columnName, ColumnIndexSelector indexSelector, FilterTuning filterTuning)
static ImmutableBitmap	computeDefaultBitmapResults(Filter filter, ColumnIndexSelector selector)
static Filter	convertToCNFFromQueryContext(Query query, Filter filter)
static double	estimateSelectivity(Iterator<ImmutableBitmap> bitmaps, long totalNumRows)
static boolean	filterMatchesNull(Filter filter)
static BitmapColumnIndex	makeNullIndex(boolean matchesNull, ColumnIndexSelector selector)
static BitmapColumnIndex	makePredicateIndex(String column, ColumnIndexSelector selector, DruidPredicateFactory predicateFactory)
static ValueMatcher	makeValueMatcher(ColumnSelectorFactory columnSelectorFactory, String columnName, DruidPredicateFactory predicateFactory) Create a ValueMatcher that applies a predicate to row values.
static ValueMatcher	makeValueMatcher(ColumnSelectorFactory columnSelectorFactory, String columnName, String value) Create a ValueMatcher that compares row values to the provided string.
static Optional<Filter>	maybeAnd(List<Filter> filters) Like and(java.util.List<org.apache.druid.query.filter.Filter>), but returns an empty Optional instead of throwing an exception if "filters" is empty or only contains nulls.
static Optional<Filter>	maybeOr(List<Filter> filters) Like or(java.util.List<org.apache.druid.query.filter.Filter>), but returns an empty Optional instead of throwing an exception if "filters" is empty or only contains nulls.
static Filter	or(List<Filter> filters) Create a filter representing an OR relationship across a list of filters.
static boolean	supportsSelectivityEstimation(Filter filter, String dimension, ColumnSelector columnSelector, ColumnIndexSelector indexSelector)
static Filter	toCnf(Filter current)
static Filter	toFilter(DimFilter dimFilter) Convert a DimFilter to a Filter.
static List<Filter>	toFilters(List<DimFilter> dimFilters) Convert a list of DimFilters to a list of Filters.
static List<Filter>	toNormalizedOrClauses(Filter filter)

Methods inherited from class java.lang.Object

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

Constructor Detail

Filters

public Filters()

Method Detail

toFilters

public static List<Filter> toFilters(List<DimFilter> dimFilters)

Convert a list of DimFilters to a list of Filters.

Parameters:

dimFilters - list of DimFilters, should all be non-null

Returns:

list of Filters

toFilter

@Nullable
public static Filter toFilter(@Nullable
                                        DimFilter dimFilter)

Convert a DimFilter to a Filter.

Parameters:

dimFilter - dimFilter

Returns:

converted filter, or null if input was null

makeValueMatcher

public static ValueMatcher makeValueMatcher(ColumnSelectorFactory columnSelectorFactory,
                                            String columnName,
                                            String value)

Create a ValueMatcher that compares row values to the provided string.

An implementation of this method should be able to handle dimensions of various types.

Parameters:

columnSelectorFactory - Selector for columns.

columnName - The column to filter.

value - The value to match against, represented as a String.

Returns:

An object that matches row values on the provided value.

makeValueMatcher

public static ValueMatcher makeValueMatcher(ColumnSelectorFactory columnSelectorFactory,
                                            String columnName,
                                            DruidPredicateFactory predicateFactory)

Create a ValueMatcher that applies a predicate to row values.

The caller provides a predicate factory that can create a predicate for each value type supported by Druid. See DruidPredicateFactory for more information.

When creating the ValueMatcher, the ValueMatcherFactory implementation should decide what type of predicate to create from the predicate factory based on the ValueType of the specified dimension.

Parameters:

columnSelectorFactory - Selector for columns.

columnName - The column to filter.

predicateFactory - Predicate factory

Returns:

An object that applies a predicate to row values

makePredicateIndex

@Nullable
public static BitmapColumnIndex makePredicateIndex(String column,
                                                             ColumnIndexSelector selector,
                                                             DruidPredicateFactory predicateFactory)

makeNullIndex

public static BitmapColumnIndex makeNullIndex(boolean matchesNull,
                                              ColumnIndexSelector selector)

computeDefaultBitmapResults

public static ImmutableBitmap computeDefaultBitmapResults(Filter filter,
                                                          ColumnIndexSelector selector)

supportsSelectivityEstimation

public static boolean supportsSelectivityEstimation(Filter filter,
                                                    String dimension,
                                                    ColumnSelector columnSelector,
                                                    ColumnIndexSelector indexSelector)

estimateSelectivity

public static double estimateSelectivity(Iterator<ImmutableBitmap> bitmaps,
                                         long totalNumRows)

convertToCNFFromQueryContext

@Nullable
public static Filter convertToCNFFromQueryContext(Query query,
                                                            @Nullable
                                                            Filter filter)

toCnf

public static Filter toCnf(Filter current)
                    throws CNFFilterExplosionException

Throws:

CNFFilterExplosionException

checkFilterTuningUseIndex

public static boolean checkFilterTuningUseIndex(String columnName,
                                                ColumnIndexSelector indexSelector,
                                                @Nullable
                                                FilterTuning filterTuning)

and

public static Filter and(List<Filter> filters)

Create a filter representing an AND relationship across a list of filters. Deduplicates filters, flattens stacks, and removes null filters and literal "false" filters.

Parameters:

filters - List of filters

Returns:

If "filters" has more than one filter remaining after processing, returns AndFilter. If "filters" has a single element remaining after processing, return that filter alone.

Throws:

IllegalArgumentException - if "filters" is empty or only contains nulls

maybeAnd

public static Optional<Filter> maybeAnd(List<Filter> filters)

Like and(java.util.List<org.apache.druid.query.filter.Filter>), but returns an empty Optional instead of throwing an exception if "filters" is empty or only contains nulls.

or

public static Filter or(List<Filter> filters)

Create a filter representing an OR relationship across a list of filters. Deduplicates filters, flattens stacks, and removes null filters and literal "false" filters.

Parameters:

filters - List of filters

Returns:

If "filters" has more than one filter remaining after processing, returns OrFilter. If "filters" has a single element remaining after processing, return that filter alone.

Throws:

IllegalArgumentException - if "filters" is empty

maybeOr

public static Optional<Filter> maybeOr(List<Filter> filters)

Like or(java.util.List<org.apache.druid.query.filter.Filter>), but returns an empty Optional instead of throwing an exception if "filters" is empty or only contains nulls.

toNormalizedOrClauses

public static List<Filter> toNormalizedOrClauses(Filter filter)
                                          throws CNFFilterExplosionException

Parameters:

filter - the filter.

Returns:

The normalized or clauses for the provided filter.

Throws:

CNFFilterExplosionException

filterMatchesNull

public static boolean filterMatchesNull(Filter filter)