Package org.apache.parquet.filter2.compat

Class FilterCompat

java.lang.Object

org.apache.parquet.filter2.compat.FilterCompat

public class FilterCompat
extends Object

Parquet currently has two ways to specify a filter for dropping records at read time. The first way, that only supports filtering records during record assembly, is found in org.apache.parquet.filter. The new API (found in org.apache.parquet.filter2) supports also filtering entire rowgroups of records without reading them at all.

This class defines a common interface that both of these filters share, FilterCompat.Filter. A Filter can be either an UnboundRecordFilter from the old API, or a FilterPredicate from the new API, or a sentinel no-op filter.

Having this common interface simplifies passing a filter through the read path of parquet's codebase.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	FilterCompat.Filter
static class	FilterCompat.FilterPredicateCompat
static class	FilterCompat.NoOpFilter
static class	FilterCompat.UnboundRecordFilterCompat
static interface	FilterCompat.Visitor<T>	Anyone wanting to use a FilterCompat.Filter need only implement this interface, per the visitor pattern.

Field Summary

Fields

Modifier and Type	Field	Description
static FilterCompat.Filter	NOOP

Constructor Summary

Constructors

Constructor	Description
FilterCompat()

Method Summary

Modifier and Type	Method	Description
static FilterCompat.Filter	get(UnboundRecordFilter unboundRecordFilter)	Given an UnboundRecordFilter, return a Filter that wraps it.
static FilterCompat.Filter	get(FilterPredicate filterPredicate)	Given a FilterPredicate, return a Filter that wraps it.
static FilterCompat.Filter	get(FilterPredicate filterPredicate, UnboundRecordFilter unboundRecordFilter)	Given either a FilterPredicate or the class of an UnboundRecordFilter, or neither (but not both) return a Filter that wraps whichever was provided.
static boolean	isFilteringRequired(FilterCompat.Filter filter)	Returns whether filtering is required based on the specified filter.

Methods inherited from class java.lang.Object

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

Field Detail

NOOP

public static final FilterCompat.Filter NOOP

Constructor Detail

FilterCompat

public FilterCompat()

Method Detail

get

public static FilterCompat.Filter get(FilterPredicate filterPredicate)

Given a FilterPredicate, return a Filter that wraps it. This method also logs the filter being used and rewrites the predicate to not include the not() operator.

Parameters:

filterPredicate - a filter predicate

Returns:

a filter for the given predicate

get

public static FilterCompat.Filter get(UnboundRecordFilter unboundRecordFilter)

Given an UnboundRecordFilter, return a Filter that wraps it.

Parameters:

unboundRecordFilter - an unbound record filter

Returns:

a Filter for the given record filter (from the old API)

get

public static FilterCompat.Filter get(FilterPredicate filterPredicate,
                                      UnboundRecordFilter unboundRecordFilter)

Given either a FilterPredicate or the class of an UnboundRecordFilter, or neither (but not both) return a Filter that wraps whichever was provided.

Either filterPredicate or unboundRecordFilterClass must be null, or an exception is thrown.

If both are null, the no op filter will be returned.

Parameters:

filterPredicate - a filter predicate, or null

unboundRecordFilter - an unbound record filter, or null

Returns:

a Filter wrapping either the predicate or the unbound record filter (from the old API)

isFilteringRequired

public static boolean isFilteringRequired(FilterCompat.Filter filter)

Returns whether filtering is required based on the specified filter. It is used to avoid any significant steps to prepare filtering if NOOP is used.

Parameters:

filter - the filter to be checked

Returns:

false if the filter is null or is a no-op filter, true otherwise.