/**
* 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.exec.planner.logical;
import java.util.List;
import java.util.Map;
import org.apache.drill.common.expression.FieldReference;
import org.apache.drill.common.logical.data.LogicalOperator;
import org.apache.drill.common.logical.data.Order;
import org.apache.drill.common.logical.data.Order.Ordering;
import org.apache.drill.exec.planner.torel.ConversionContext;
import org.eigenbase.rel.InvalidRelException;
import org.eigenbase.rel.RelCollation;
import org.eigenbase.rel.RelCollationImpl;
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 org.eigenbase.rex.RexNode;
import com.google.common.collect.Lists;
import com.google.common.collect.Maps;
/**
* 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);
}
/** Creates a DrillSortRel with offset and fetch. */
public DrillSortRel(RelOptCluster cluster, RelTraitSet traits, RelNode input, RelCollation collation, RexNode offset, RexNode fetch) {
super(cluster, traits, input, collation, offset, fetch);
}
@Override
public DrillSortRel copy(RelTraitSet traitSet, RelNode input, RelCollation collation, RexNode offset, RexNode fetch) {
return new DrillSortRel(getCluster(), traitSet, input, collation, offset, fetch);
}
@Override
public LogicalOperator implement(DrillImplementor implementor) {
final Order.Builder builder = Order.builder();
builder.setInput(implementor.visitChild(this, 0, getChild()));
final List<String> childFields = getChild().getRowType().getFieldNames();
for(RelFieldCollation fieldCollation : this.collation.getFieldCollations()){
builder.addOrdering(fieldCollation.getDirection(),
new FieldReference(childFields.get(fieldCollation.getFieldIndex())),
fieldCollation.nullDirection);
}
return builder.build();
}
public static RelNode convert(Order order, ConversionContext context) throws InvalidRelException{
// if there are compound expressions in the order by, we need to convert into projects on either side.
RelNode input = context.toRel(order.getInput());
List<String> fields = input.getRowType().getFieldNames();
// build a map of field names to indices.
Map<String, Integer> fieldMap = Maps.newHashMap();
int i =0;
for(String field : fields){
fieldMap.put(field, i);
i++;
}
List<RelFieldCollation> collations = Lists.newArrayList();
for(Ordering o : order.getOrderings()){
String fieldName = ExprHelper.getFieldName(o.getExpr());
int fieldId = fieldMap.get(fieldName);
RelFieldCollation c = new RelFieldCollation(fieldId, o.getDirection(), o.getNullDirection());
}
return new DrillSortRel(context.getCluster(), context.getLogicalTraits(), input, RelCollationImpl.of(collations));
}
}