/**
* 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 org.apache.drill.exec.expr.fn.FunctionImplementationRegistry;
import org.eigenbase.rel.ProjectRelBase;
import org.eigenbase.rel.RelFactories.ProjectFactory;
import org.eigenbase.rel.rules.MergeProjectRule;
import org.eigenbase.relopt.RelOptRuleCall;
import org.eigenbase.rex.RexCall;
import org.eigenbase.rex.RexNode;
public class DrillMergeProjectRule extends MergeProjectRule {
private FunctionImplementationRegistry functionRegistry;
private static DrillMergeProjectRule INSTANCE = null;
public static DrillMergeProjectRule getInstance(boolean force, ProjectFactory pFactory, FunctionImplementationRegistry functionRegistry) {
if (INSTANCE == null) {
INSTANCE = new DrillMergeProjectRule(force, pFactory, functionRegistry);
}
return INSTANCE;
}
private DrillMergeProjectRule(boolean force, ProjectFactory pFactory, FunctionImplementationRegistry functionRegistry) {
super(force, pFactory);
this.functionRegistry = functionRegistry;
}
@Override
public boolean matches(RelOptRuleCall call) {
ProjectRelBase topProject = call.rel(0);
ProjectRelBase bottomProject = call.rel(1);
// We have a complex output type do not fire the merge project rule
if (checkComplexOutput(topProject) || checkComplexOutput(bottomProject)) {
return false;
}
return true;
}
private boolean checkComplexOutput(ProjectRelBase project) {
for (RexNode expr: project.getChildExps()) {
if (expr instanceof RexCall) {
if (functionRegistry.isFunctionComplexOutput(((RexCall) expr).getOperator().getName())) {
return true;
}
}
}
return false;
}
}