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 ImmutableBitmap	allFalse(BitmapIndexSelector selector)
static ImmutableBitmap	allTrue(BitmapIndexSelector selector)
static Filter	and(List<Filter> filterList) Create a filter representing an AND relationship across a list of filters.
static Filter	convertToCNFFromQueryContext(Query query, Filter filter)
static double	estimateSelectivity(BitmapIndex bitmapIndex, it.unimi.dsi.fastutil.ints.IntList bitmaps, long totalNumRows) Return an estimated selectivity for bitmaps for the dimension values given by dimValueIndexes.
static double	estimateSelectivity(Iterator<ImmutableBitmap> bitmaps, long totalNumRows) Return an estimated selectivity for bitmaps given by an iterator.
static double	estimateSelectivity(String dimension, BitmapIndexSelector indexSelector, com.google.common.base.Predicate<String> predicate) Return an estimated selectivity for bitmaps of all values matching the given predicate.
static boolean	filterMatchesNull(Filter filter)
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 <T> T	matchPredicate(String dimension, BitmapIndexSelector selector, BitmapResultFactory<T> bitmapResultFactory, com.google.common.base.Predicate<String> predicate) Return the union of bitmaps for all values matching a particular predicate.
static Iterable<ImmutableBitmap>	matchPredicateNoUnion(String dimension, BitmapIndexSelector selector, com.google.common.base.Predicate<String> predicate) Return an iterable of bitmaps for all values matching a particular predicate.
static Filter	or(Set<Filter> filterSet) Create a filter representing an OR relationship across a set of filters.
static boolean	shouldUseBitmapIndex(Filter filter, BitmapIndexSelector indexSelector, FilterTuning filterTuning) This method provides a "standard" implementation of Filter.shouldUseBitmapIndex(BitmapIndexSelector) which takes a Filter, a BitmapIndexSelector, and FilterTuning to determine if: a) the filter supports bitmap indexes for all required columns b) the filter tuning specifies that it should use the index c) the cardinality of the column is above the minimum threshold and below the maximum threshold to use the index If all these things are true, QueryableIndexStorageAdapter will utilize the indexes.
static Filter	toCnf(Filter current)
static Filter	toFilter(DimFilter dimFilter) Convert a DimFilter to a Filter.
static Set<Filter>	toFilters(List<DimFilter> dimFilters) Convert a list of DimFilters to a list of Filters.
static Set<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 Set<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

allFalse

public static ImmutableBitmap allFalse(BitmapIndexSelector selector)

allTrue

public static ImmutableBitmap allTrue(BitmapIndexSelector selector)

matchPredicate

public static <T> T matchPredicate(String dimension,
                                   BitmapIndexSelector selector,
                                   BitmapResultFactory<T> bitmapResultFactory,
                                   com.google.common.base.Predicate<String> predicate)

Return the union of bitmaps for all values matching a particular predicate.

Parameters:

dimension - dimension to look at

selector - bitmap selector

bitmapResultFactory -

predicate - predicate to use

Returns:

bitmap of matching rows

See Also:

estimateSelectivity(String, BitmapIndexSelector, Predicate)

matchPredicateNoUnion

public static Iterable<ImmutableBitmap> matchPredicateNoUnion(String dimension,
                                                              BitmapIndexSelector selector,
                                                              com.google.common.base.Predicate<String> predicate)

Return an iterable of bitmaps for all values matching a particular predicate. Unioning these bitmaps yields the same result that matchPredicate(String, BitmapIndexSelector, BitmapResultFactory, Predicate) would have returned.

Parameters:

dimension - dimension to look at

selector - bitmap selector

predicate - predicate to use

Returns:

iterable of bitmaps of matching rows

estimateSelectivity

public static double estimateSelectivity(String dimension,
                                         BitmapIndexSelector indexSelector,
                                         com.google.common.base.Predicate<String> predicate)

Return an estimated selectivity for bitmaps of all values matching the given predicate.

Parameters:

dimension - dimension to look at

indexSelector - bitmap selector

predicate - predicate to use

Returns:

estimated selectivity

See Also:

matchPredicate(String, BitmapIndexSelector, BitmapResultFactory, Predicate)

estimateSelectivity

public static double estimateSelectivity(BitmapIndex bitmapIndex,
                                         it.unimi.dsi.fastutil.ints.IntList bitmaps,
                                         long totalNumRows)

Return an estimated selectivity for bitmaps for the dimension values given by dimValueIndexes.

Parameters:

bitmapIndex - bitmap index

bitmaps - bitmaps to extract, by index

totalNumRows - number of rows in the column associated with this bitmap index

Returns:

estimated selectivity

estimateSelectivity

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

Return an estimated selectivity for bitmaps given by an iterator.

Parameters:

bitmaps - iterator of bitmaps

totalNumRows - number of rows in the column associated with this bitmap index

Returns:

estimated selectivity

convertToCNFFromQueryContext

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

toCnf

public static Filter toCnf(Filter current)

shouldUseBitmapIndex

public static boolean shouldUseBitmapIndex(Filter filter,
                                           BitmapIndexSelector indexSelector,
                                           @Nullable
                                           FilterTuning filterTuning)

This method provides a "standard" implementation of Filter.shouldUseBitmapIndex(BitmapIndexSelector) which takes a Filter, a BitmapIndexSelector, and FilterTuning to determine if: a) the filter supports bitmap indexes for all required columns b) the filter tuning specifies that it should use the index c) the cardinality of the column is above the minimum threshold and below the maximum threshold to use the index If all these things are true, QueryableIndexStorageAdapter will utilize the indexes.

and

@Nullable
public static Filter and(List<Filter> filterList)

Create a filter representing an AND relationship across a list of filters.

Parameters:

filterList - List of filters

Returns:

If filterList has more than one element, return an AND filter composed of the filters from filterList If filterList has a single element, return that element alone If filterList is empty, return null

or

@Nullable
public static Filter or(Set<Filter> filterSet)

Create a filter representing an OR relationship across a set of filters.

Parameters:

filterSet - Set of filters

Returns:

If filterSet has more than one element, return an OR filter composed of the filters from filterSet If filterSet has a single element, return that element alone If filterSet is empty, return null

toNormalizedOrClauses

public static Set<Filter> toNormalizedOrClauses(Filter filter)

Parameters:

filter - the filter.

Returns:

The normalized or clauses for the provided filter.

filterMatchesNull

public static boolean filterMatchesNull(Filter filter)