/**
* 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 com.google.common.collect.Lists;
import net.hydromatic.linq4j.Ord;
import net.hydromatic.optiq.util.BitSets;
import org.apache.drill.common.expression.ExpressionPosition;
import org.apache.drill.common.expression.FieldReference;
import org.apache.drill.common.expression.FunctionCall;
import org.apache.drill.common.expression.LogicalExpression;
import org.apache.drill.common.expression.ValueExpressions;
import org.apache.drill.common.logical.data.LogicalOperator;
import org.apache.drill.common.logical.data.Order;
import org.apache.drill.exec.planner.common.DrillWindowRelBase;
import org.eigenbase.rel.AggregateCall;
import org.eigenbase.rel.RelFieldCollation;
import org.eigenbase.rel.RelNode;
import org.eigenbase.relopt.RelOptCluster;
import org.eigenbase.relopt.RelTraitSet;
import org.eigenbase.reltype.RelDataType;
import org.eigenbase.rex.RexLiteral;
import java.util.List;
public class DrillWindowRel extends DrillWindowRelBase implements DrillRel {
/**
* Creates a window relational expression.
*
* @param cluster Cluster
* @param traits
* @param child Input relational expression
* @param rowType Output row type
* @param windows Windows
*/
public DrillWindowRel(
RelOptCluster cluster,
RelTraitSet traits,
RelNode child,
List<RexLiteral> constants,
RelDataType rowType,
List<Window> windows) {
super(cluster, traits, child, constants, rowType, windows);
}
@Override
public RelNode copy(RelTraitSet traitSet, List<RelNode> inputs) {
return new DrillWindowRel(getCluster(), traitSet, sole(inputs), constants, getRowType(), windows);
}
@Override
public LogicalOperator implement(DrillImplementor implementor) {
final LogicalOperator inputOp = implementor.visitChild(this, 0, getChild());
org.apache.drill.common.logical.data.Window.Builder builder = new org.apache.drill.common.logical.data.Window.Builder();
final List<String> fields = getRowType().getFieldNames();
final List<String> childFields = getChild().getRowType().getFieldNames();
for (Window window : windows) {
for(RelFieldCollation orderKey : window.orderKeys.getFieldCollations()) {
builder.addOrdering(new Order.Ordering(orderKey.getDirection(), new FieldReference(fields.get(orderKey.getFieldIndex()))));
}
for (int group : BitSets.toIter(window.groupSet)) {
FieldReference fr = new FieldReference(childFields.get(group), ExpressionPosition.UNKNOWN);
builder.addWithin(fr, fr);
}
int groupCardinality = window.groupSet.cardinality();
for (Ord<AggregateCall> aggCall : Ord.zip(window.getAggregateCalls(this))) {
FieldReference ref = new FieldReference(fields.get(groupCardinality + aggCall.i));
LogicalExpression expr = toDrill(aggCall.e, childFields);
builder.addAggregation(ref, expr);
}
}
builder.setInput(inputOp);
org.apache.drill.common.logical.data.Window frame = builder.build();
return frame;
}
protected LogicalExpression toDrill(AggregateCall call, List<String> fn) {
List<LogicalExpression> args = Lists.newArrayList();
for (Integer i : call.getArgList()) {
args.add(new FieldReference(fn.get(i)));
}
// for count(1).
if (args.isEmpty()) {
args.add(new ValueExpressions.LongExpression(1l));
}
LogicalExpression expr = new FunctionCall(call.getAggregation().getName().toLowerCase(), args, ExpressionPosition.UNKNOWN);
return expr;
}
}