/*
* Copyright (c) 2007-2014 Concurrent, Inc. All Rights Reserved.
*
* Project and contact information: http://www.cascading.org/
*
* This file is part of the Cascading project.
*
* Licensed 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 cascading.lingual.optiq;
import java.util.Comparator;
import cascading.lingual.optiq.meta.Branch;
import cascading.pipe.GroupBy;
import cascading.pipe.Pipe;
import cascading.tuple.Fields;
import net.hydromatic.linq4j.function.Functions;
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.RelOptCost;
import org.eigenbase.relopt.RelOptPlanner;
import org.eigenbase.relopt.RelTraitSet;
import org.eigenbase.reltype.RelDataType;
import org.eigenbase.reltype.RelDataTypeField;
import org.eigenbase.rex.RexInputRef;
import org.eigenbase.rex.RexNode;
/**
*
*/
class CascadingSortRel extends SortRel implements CascadingRelNode
{
public CascadingSortRel( RelOptCluster cluster, RelTraitSet traits, RelNode child, RelCollation collation, RexNode offset, RexNode fetch )
{
super( cluster, traits, child, collation, offset, fetch );
assert child.getTraitSet().contains( Cascading.CONVENTION );
assert offset == null;
assert fetch == null;
}
@Override
public RelOptCost computeSelfCost( RelOptPlanner planner )
{
return super.computeSelfCost( planner ).multiplyBy( .1 );
}
@Override
public SortRel copy( RelTraitSet traitSet, RelNode newInput, RelCollation newCollation, RexNode offset, RexNode fetch )
{
return new CascadingSortRel( getCluster(), traitSet, newInput, newCollation, offset, fetch );
}
public Branch visitChild( Stack stack )
{
Branch branch = ( (CascadingRelNode) getChild() ).visitChild( stack );
Fields fields = createFields();
String name = stack.getNameFor( GroupBy.class, branch.current );
Pipe current = new GroupBy( name, branch.current, fields );
current = stack.addDebug( this, current );
return new Branch( current, branch );
}
private Fields createFields()
{
Fields fields = new Fields();
RelNode child = getChild();
RelDataType inputRowType = child.getRowType();
for( RexNode exp : fieldExps )
{
int index = ( (RexInputRef) exp ).getIndex();
RelDataTypeField typeField = inputRowType.getFieldList().get( index );
String name = typeField.getName();
fields = fields.append( new Fields( name ) );
}
for( RelFieldCollation fieldCollation : collation.getFieldCollations() )
{
String name = inputRowType.getFieldList().get( fieldCollation.getFieldIndex() ).getName();
boolean isDescending = fieldCollation.getDirection() == RelFieldCollation.Direction.Descending;
boolean isNullsFirst = fieldCollation.nullDirection == RelFieldCollation.NullDirection.FIRST;
Comparator<Comparable> comparator = Functions.<Comparable>nullsComparator( isNullsFirst, isDescending );
if( comparator != null )
fields.setComparator( name, comparator );
}
return fields;
}
}