| /* |
| * 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.calcite.rel.rules; |
| |
| import org.apache.calcite.plan.RelOptRuleCall; |
| import org.apache.calcite.plan.RelRule; |
| import org.apache.calcite.rel.core.Calc; |
| import org.apache.calcite.rex.RexOver; |
| import org.apache.calcite.rex.RexProgram; |
| import org.apache.calcite.rex.RexProgramBuilder; |
| import org.apache.calcite.tools.RelBuilderFactory; |
| |
| import org.immutables.value.Value; |
| |
| /** |
| * Planner rule that merges a |
| * {@link org.apache.calcite.rel.logical.LogicalCalc} onto a |
| * {@link org.apache.calcite.rel.logical.LogicalCalc}. |
| * |
| * <p>The resulting {@link org.apache.calcite.rel.logical.LogicalCalc} has the |
| * same project list as the upper |
| * {@link org.apache.calcite.rel.logical.LogicalCalc}, but expressed in terms of |
| * the lower {@link org.apache.calcite.rel.logical.LogicalCalc}'s inputs. |
| * |
| * @see CoreRules#CALC_MERGE |
| */ |
| @Value.Enclosing |
| public class CalcMergeRule extends RelRule<CalcMergeRule.Config> |
| implements TransformationRule { |
| |
| /** Creates a CalcMergeRule. */ |
| protected CalcMergeRule(Config config) { |
| super(config); |
| } |
| |
| @Deprecated // to be removed before 2.0 |
| public CalcMergeRule(RelBuilderFactory relBuilderFactory) { |
| this(Config.DEFAULT.withRelBuilderFactory(relBuilderFactory) |
| .as(Config.class)); |
| } |
| |
| //~ Methods ---------------------------------------------------------------- |
| |
| @Override public void onMatch(RelOptRuleCall call) { |
| final Calc topCalc = call.rel(0); |
| final Calc bottomCalc = call.rel(1); |
| |
| // Don't merge a calc which contains windowed aggregates onto a |
| // calc. That would effectively be pushing a windowed aggregate down |
| // through a filter. |
| RexProgram topProgram = topCalc.getProgram(); |
| if (RexOver.containsOver(topProgram)) { |
| return; |
| } |
| |
| // Merge the programs together. |
| |
| RexProgram mergedProgram = |
| RexProgramBuilder.mergePrograms( |
| topCalc.getProgram(), |
| bottomCalc.getProgram(), |
| topCalc.getCluster().getRexBuilder()); |
| assert mergedProgram.getOutputRowType() |
| == topProgram.getOutputRowType(); |
| final Calc newCalc = |
| topCalc.copy( |
| topCalc.getTraitSet(), |
| bottomCalc.getInput(), |
| mergedProgram); |
| |
| if (newCalc.getDigest().equals(bottomCalc.getDigest()) |
| && newCalc.getRowType().equals(bottomCalc.getRowType())) { |
| // newCalc is equivalent to bottomCalc, which means that topCalc |
| // must be trivial. Take it out of the game. |
| call.getPlanner().prune(topCalc); |
| } |
| |
| call.transformTo(newCalc); |
| } |
| |
| /** Rule configuration. */ |
| @Value.Immutable |
| public interface Config extends RelRule.Config { |
| Config DEFAULT = ImmutableCalcMergeRule.Config.of() |
| .withOperandSupplier(b0 -> |
| b0.operand(Calc.class).oneInput(b1 -> |
| b1.operand(Calc.class).anyInputs())) |
| .as(Config.class); |
| |
| @Override default CalcMergeRule toRule() { |
| return new CalcMergeRule(this); |
| } |
| } |
| } |