/*
* Licensed to CRATE Technology GmbH ("Crate") under one or more contributor
* license agreements. See the NOTICE file distributed with this work for
* additional information regarding copyright ownership. Crate 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.
*
* However, if you have executed another commercial license agreement
* with Crate these terms will supersede the license and you may use the
* software solely pursuant to the terms of the relevant commercial agreement.
*/
package io.crate.operation;
import io.crate.data.Row;
import io.crate.operation.merge.PagingIterator;
import io.crate.operation.merge.PassThroughPagingIterator;
import io.crate.operation.merge.SortedPagingIterator;
import io.crate.operation.projectors.sorting.OrderingByPosition;
import io.crate.planner.PositionalOrderBy;
import javax.annotation.Nullable;
public class PagingIterators {
public static PagingIterator<Integer, Row> create(int numUpstreams,
boolean requiresRepeat,
@Nullable PositionalOrderBy orderBy) {
if (numUpstreams == 1 || orderBy == null) {
if (requiresRepeat) {
return PassThroughPagingIterator.repeatable();
}
return PassThroughPagingIterator.oneShot();
}
return new SortedPagingIterator<>(OrderingByPosition.rowOrdering(orderBy), requiresRepeat);
}
}