/**
* 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.drill.optiq;
import java.util.List;
import net.hydromatic.linq4j.Ord;
import org.eigenbase.rel.RelCollation;
import org.eigenbase.rel.RelFieldCollation;
import org.eigenbase.rel.RelNode;
import org.eigenbase.rel.SortRel;
import org.eigenbase.relopt.RelOptCluster;
import org.eigenbase.relopt.RelTraitSet;
import com.fasterxml.jackson.databind.node.ArrayNode;
import com.fasterxml.jackson.databind.node.ObjectNode;
/**
* Sort implemented in Drill.
*/
public class DrillSortRel extends SortRel implements DrillRel {
/** Creates a DrillSortRel. */
public DrillSortRel(RelOptCluster cluster, RelTraitSet traits, RelNode input, RelCollation collation) {
super(cluster, traits, input, collation);
}
@Override
public DrillSortRel copy(RelTraitSet traitSet, RelNode input, RelCollation collation) {
return new DrillSortRel(getCluster(), traitSet, input, collation);
}
@Override
public int implement(DrillImplementor implementor) {
int inputId = implementor.visitChild(this, 0, getChild());
final List<String> childFields = getChild().getRowType().getFieldNames();
/*
* E.g. { op: "order", input: 4, ordering: [ {order: "asc", expr: "deptId"} ] }
*/
final ObjectNode order = implementor.mapper.createObjectNode();
order.put("op", "order");
order.put("input", inputId);
final ArrayNode orderings = implementor.mapper.createArrayNode();
order.put("orderings", orderings);
for (Ord<RelFieldCollation> fieldCollation : Ord.zip(this.collation.getFieldCollations())) {
final ObjectNode ordering = implementor.mapper.createObjectNode();
ordering.put("order", toDrill(fieldCollation.e));
ordering.put("expr", childFields.get(fieldCollation.e.getFieldIndex()));
switch (fieldCollation.e.nullDirection) {
case FIRST:
ordering.put("nullCollation", "first");
break;
default:
ordering.put("nullCollation", "last");
break;
}
orderings.add(ordering);
}
return implementor.add(order);
}
private static String toDrill(RelFieldCollation collation) {
switch (collation.getDirection()) {
case Ascending:
return "asc";
case Descending:
return "desc";
default:
throw new AssertionError(collation.getDirection());
}
}
}