org.apache.druid.segment.join.InlineJoinableFactory Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of druid-processing Show documentation
Show all versions of druid-processing Show documentation
A module that is everything required to understands Druid Segments
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.druid.segment.join;
import org.apache.druid.java.util.common.DateTimes;
import org.apache.druid.query.DataSource;
import org.apache.druid.query.InlineDataSource;
import org.apache.druid.segment.join.table.IndexedTable;
import org.apache.druid.segment.join.table.IndexedTableJoinable;
import org.apache.druid.segment.join.table.RowBasedIndexedTable;
import java.util.Optional;
import java.util.Set;
/**
* A {@link JoinableFactory} for {@link InlineDataSource}.
* It works by building an {@link IndexedTable}.
*
* It is not valid to pass any other DataSource type to the "build" method.
*/
public class InlineJoinableFactory implements JoinableFactory
{
@Override
public boolean isDirectlyJoinable(DataSource dataSource)
{
// this should always be true if this is access through MapJoinableFactory, but check just in case...
// further, this should not ever be legitimately called, because this method is used to avoid subquery joins
// which use the InlineJoinableFactory
return dataSource instanceof InlineDataSource;
}
@Override
public Optional build(final DataSource dataSource, final JoinConditionAnalysis condition)
{
InlineDataSource inlineDataSource = (InlineDataSource) dataSource;
if (condition.canHashJoin()) {
final Set rightKeyColumns = condition.getRightEquiConditionKeys();
return Optional.of(
new IndexedTableJoinable(
new RowBasedIndexedTable<>(
inlineDataSource.getRowsAsList(),
inlineDataSource.rowAdapter(),
inlineDataSource.getRowSignature(),
rightKeyColumns,
DateTimes.nowUtc().toString()
)
)
);
} else {
return Optional.empty();
}
}
}