Package org.apache.druid.query.filter

Class NullFilter

java.lang.Object

org.apache.druid.query.filter.AbstractOptimizableDimFilter

org.apache.druid.query.filter.NullFilter

All Implemented Interfaces:

Cacheable, DimFilter, Filter

public class NullFilter
extends AbstractOptimizableDimFilter
implements Filter

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	NullFilter.NullPredicateFactory

Nested classes/interfaces inherited from interface org.apache.druid.query.filter.DimFilter

DimFilter.DimFilterToStringBuilder

Constructor Summary

Constructors

Constructor	Description
NullFilter(String column, FilterTuning filterTuning)

Method Summary

Modifier and Type	Method	Description
boolean	canVectorizeMatcher(ColumnInspector inspector)	Returns true if this filter can produce a vectorized matcher from its "makeVectorMatcher" method.
boolean	equals(Object o)
static NullFilter	forColumn(String column)
BitmapColumnIndex	getBitmapColumnIndex(ColumnIndexSelector selector)	Returns a BitmapColumnIndex if this filter supports using a bitmap index for filtering for the given input ColumnIndexSelector.
byte[]	getCacheKey()	Get a byte array used as a cache key.
String	getColumn()
com.google.common.collect.RangeSet<String>	getDimensionRangeSet(String dimension)	Returns a RangeSet that represents the possible range of the input dimension for this DimFilter.This is applicable to filters that use dimensions such as select, in, bound, and logical filters such as and, or, not.
FilterTuning	getFilterTuning()
Set<String>	getRequiredColumns()	Set of columns used by a filter.
int	hashCode()
ValueMatcher	makeMatcher(ColumnSelectorFactory factory)	Get a ValueMatcher that applies this filter to row values.
VectorValueMatcher	makeVectorMatcher(VectorColumnSelectorFactory factory)	Get a VectorValueMatcher that applies this filter to row vectors.
Filter	rewriteRequiredColumns(Map<String,String> columnRewrites)	Return a copy of this filter that is identical to the this filter except that it operates on different columns, based on a renaming map where the key is the column to be renamed in the filter, and the value is the new column name.
boolean	supportsRequiredColumnRewrite()	Returns true is this filter is able to return a copy of this filter that is identical to this filter except that it operates on different columns, based on a renaming map.
Filter	toFilter()	Returns a Filter that implements this DimFilter.
String	toString()

Methods inherited from class org.apache.druid.query.filter.AbstractOptimizableDimFilter

optimize, toOptimizedFilter

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.apache.druid.query.filter.Filter

makeFilterBundle

Constructor Detail

NullFilter

public NullFilter(String column,
                  @Nullable
                  FilterTuning filterTuning)

Method Detail

forColumn

public static NullFilter forColumn(String column)

getColumn

public String getColumn()

getFilterTuning

@Nullable
public FilterTuning getFilterTuning()

getCacheKey

public byte[] getCacheKey()

Description copied from interface: Cacheable

Get a byte array used as a cache key.

Specified by:

getCacheKey in interface Cacheable

Returns:

a cache key

toFilter

public Filter toFilter()

Description copied from interface: DimFilter

Returns a Filter that implements this DimFilter. This does not generally involve optimizing the DimFilter, so it does make sense to optimize first and then call toFilter on the resulting DimFilter.

Specified by:

toFilter in interface DimFilter

Returns:

a Filter that implements this DimFilter, or null if this DimFilter is a no-op.

getDimensionRangeSet

@Nullable
public com.google.common.collect.RangeSet<String> getDimensionRangeSet(String dimension)

Description copied from interface: DimFilter

Returns a RangeSet that represents the possible range of the input dimension for this DimFilter.This is applicable to filters that use dimensions such as select, in, bound, and logical filters such as and, or, not. Null represents that the range cannot be determined, and will be returned for filters such as javascript and regex where there's no easy way to determine the filtered range. It is treated the same way as an all range in most cases, however there are some subtle difference at logical filters such as not filter, where complement of all is nothing while complement of null is still null.

Specified by:

getDimensionRangeSet in interface DimFilter

Parameters:

dimension - name of the dimension to get range for

Returns:

a RangeSet that represent the possible range of the input dimension, or null if it is not possible to determine for this DimFilter.

getBitmapColumnIndex

@Nullable
public BitmapColumnIndex getBitmapColumnIndex(ColumnIndexSelector selector)

Description copied from interface: Filter

Returns a BitmapColumnIndex if this filter supports using a bitmap index for filtering for the given input ColumnIndexSelector. The BitmapColumnIndex can be used to compute into a bitmap indicating rows that match this filter result BitmapColumnIndex.computeBitmapResult(BitmapResultFactory, boolean), or examine details about the index prior to computing it, via BitmapColumnIndex.getIndexCapabilities().

Specified by:

getBitmapColumnIndex in interface Filter

Parameters:

selector - Object used to create BitmapColumnIndex

Returns:

BitmapColumnIndex that can build ImmutableBitmap of matched row numbers

makeMatcher

public ValueMatcher makeMatcher(ColumnSelectorFactory factory)

Description copied from interface: Filter

Get a ValueMatcher that applies this filter to row values.

Specified by:

makeMatcher in interface Filter

Parameters:

factory - Object used to create ValueMatchers

Returns:

ValueMatcher that applies this filter to row values.

makeVectorMatcher

public VectorValueMatcher makeVectorMatcher(VectorColumnSelectorFactory factory)

Description copied from interface: Filter

Get a VectorValueMatcher that applies this filter to row vectors.

Specified by:

makeVectorMatcher in interface Filter

Parameters:

factory - Object used to create ValueMatchers

Returns:

VectorValueMatcher that applies this filter to row vectors.

canVectorizeMatcher

public boolean canVectorizeMatcher(ColumnInspector inspector)

Description copied from interface: Filter

Returns true if this filter can produce a vectorized matcher from its "makeVectorMatcher" method.

Specified by:

canVectorizeMatcher in interface Filter

Parameters:

inspector - Supplies type information for the selectors this filter will match against

getRequiredColumns

public Set<String> getRequiredColumns()

Description copied from interface: Filter

Set of columns used by a filter.

Specified by:

getRequiredColumns in interface DimFilter

Specified by:

getRequiredColumns in interface Filter

Returns:

a HashSet that represents all columns' name which the DimFilter required to do filter.

supportsRequiredColumnRewrite

public boolean supportsRequiredColumnRewrite()

Description copied from interface: Filter

Returns true is this filter is able to return a copy of this filter that is identical to this filter except that it operates on different columns, based on a renaming map.

Specified by:

supportsRequiredColumnRewrite in interface Filter

rewriteRequiredColumns

public Filter rewriteRequiredColumns(Map<String,String> columnRewrites)

Description copied from interface: Filter

Return a copy of this filter that is identical to the this filter except that it operates on different columns, based on a renaming map where the key is the column to be renamed in the filter, and the value is the new column name. For example, if I have a filter (A = hello), and I have a renaming map (A -> B), this should return the filter (B = hello)

Specified by:

rewriteRequiredColumns in interface Filter

Parameters:

columnRewrites - Column rewrite map

Returns:

Copy of this filter that operates on new columns based on the rewrite map

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object