com.hazelcast.org.apache.calcite.rel.rules.ProjectToCalcRule Maven / Gradle / Ivy
/*
* 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 com.hazelcast.org.apache.calcite.rel.rules;
import com.hazelcast.org.apache.calcite.plan.RelOptRule;
import com.hazelcast.org.apache.calcite.plan.RelOptRuleCall;
import com.hazelcast.org.apache.calcite.rel.RelNode;
import com.hazelcast.org.apache.calcite.rel.core.RelFactories;
import com.hazelcast.org.apache.calcite.rel.logical.LogicalCalc;
import com.hazelcast.org.apache.calcite.rel.logical.LogicalProject;
import com.hazelcast.org.apache.calcite.rex.RexProgram;
import com.hazelcast.org.apache.calcite.tools.RelBuilderFactory;
/**
* Rule to convert a
* {@link com.hazelcast.org.apache.calcite.rel.logical.LogicalProject} to a
* {@link com.hazelcast.org.apache.calcite.rel.logical.LogicalCalc}
*
* The rule does not fire if the child is a
* {@link com.hazelcast.org.apache.calcite.rel.logical.LogicalProject},
* {@link com.hazelcast.org.apache.calcite.rel.logical.LogicalFilter} or
* {@link com.hazelcast.org.apache.calcite.rel.logical.LogicalCalc}. If it did, then the same
* {@link com.hazelcast.org.apache.calcite.rel.logical.LogicalCalc} would be formed via
* several transformation paths, which is a waste of effort.
*
* @see FilterToCalcRule
*/
public class ProjectToCalcRule extends RelOptRule implements TransformationRule {
//~ Static fields/initializers ---------------------------------------------
public static final ProjectToCalcRule INSTANCE =
new ProjectToCalcRule(RelFactories.LOGICAL_BUILDER);
//~ Constructors -----------------------------------------------------------
/**
* Creates a ProjectToCalcRule.
*
* @param relBuilderFactory Builder for relational expressions
*/
public ProjectToCalcRule(RelBuilderFactory relBuilderFactory) {
super(operand(LogicalProject.class, any()), relBuilderFactory, null);
}
//~ Methods ----------------------------------------------------------------
public void onMatch(RelOptRuleCall call) {
final LogicalProject project = call.rel(0);
final RelNode input = project.getInput();
final RexProgram program =
RexProgram.create(
input.getRowType(),
project.getProjects(),
null,
project.getRowType(),
project.getCluster().getRexBuilder());
final LogicalCalc calc = LogicalCalc.create(input, program);
call.transformTo(calc);
}
}