/**
* 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.physical;
import org.apache.calcite.rel.RelNode;
import org.apache.calcite.plan.ConventionTraitDef;
import org.apache.calcite.plan.RelOptRule;
import org.apache.calcite.plan.RelOptRuleCall;
import org.apache.calcite.plan.RelTrait;
import org.apache.calcite.plan.RelTraitSet;
import org.apache.calcite.plan.volcano.RelSubset;
public abstract class SubsetTransformer<T extends RelNode, E extends Exception> {
static final org.slf4j.Logger logger = org.slf4j.LoggerFactory.getLogger(SubsetTransformer.class);
public abstract RelNode convertChild(T current, RelNode child) throws E;
private final RelOptRuleCall call;
public SubsetTransformer(RelOptRuleCall call) {
this.call = call;
}
public RelTraitSet newTraitSet(RelTrait... traits) {
RelTraitSet set = call.getPlanner().emptyTraitSet();
for (RelTrait t : traits) {
set = set.plus(t);
}
return set;
}
boolean go(T n, RelNode candidateSet) throws E {
if ( !(candidateSet instanceof RelSubset) ) {
return false;
}
boolean transform = false;
for (RelNode rel : ((RelSubset)candidateSet).getRelList()) {
if (isPhysical(rel)) {
RelNode newRel = RelOptRule.convert(candidateSet, rel.getTraitSet().plus(Prel.DRILL_PHYSICAL));
RelNode out = convertChild(n, newRel);
if (out != null) {
call.transformTo(out);
transform = true;
}
}
}
return transform;
}
private boolean isPhysical(RelNode n){
return n.getTraitSet().getTrait(ConventionTraitDef.INSTANCE).equals(Prel.DRILL_PHYSICAL);
}
private boolean isDefaultDist(RelNode n) {
return n.getTraitSet().getTrait(DrillDistributionTraitDef.INSTANCE).equals(DrillDistributionTrait.DEFAULT);
}
}