HanumathRao commented on code in PR #3597: URL: https://github.com/apache/calcite/pull/3597#discussion_r1445132866
########## core/src/main/java/org/apache/calcite/rel/rules/SingleValueOptimizationRules.java: ########## @@ -0,0 +1,361 @@ +/* + * 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.RelOptRule; +import org.apache.calcite.plan.RelOptRuleCall; +import org.apache.calcite.plan.RelRule; +import org.apache.calcite.rel.RelNode; +import org.apache.calcite.rel.core.Join; +import org.apache.calcite.rel.core.JoinRelType; +import org.apache.calcite.rel.core.Project; +import org.apache.calcite.rel.core.Values; +import org.apache.calcite.rel.logical.LogicalValues; +import org.apache.calcite.rex.RexBuilder; +import org.apache.calcite.rex.RexInputRef; +import org.apache.calcite.rex.RexNode; +import org.apache.calcite.rex.RexShuttle; +import org.apache.calcite.rex.RexUtil; +import org.apache.calcite.sql.fun.SqlStdOperatorTable; +import org.apache.calcite.tools.RelBuilder; + +import org.checkerframework.checker.nullness.qual.Nullable; +import org.immutables.value.Value; + +import java.util.ArrayList; +import java.util.BitSet; +import java.util.List; +import java.util.function.BiFunction; +import java.util.function.Predicate; +import java.util.stream.Collectors; + +/** + * Collection of rules which simplify sections of query plan which are known to + * produce single row. + * + * <p>Conventionally, the way to represent a single row relational expression is + * with a {@link Values} that has one tuple. + * + * @see LogicalValues#createOneRow + */ +public abstract class SingleValueOptimizationRules { + + public static final RelOptRule JOIN_LEFT_INSTANCE = + SingleValueOptimizationRules.JoinLeftSingleRuleConfig.DEFAULT.toRule(); + + public static final RelOptRule JOIN_RIGHT_INSTANCE = + SingleValueOptimizationRules.JoinRightSingleRuleConfig.DEFAULT.toRule(); + + public static final RelOptRule JOIN_LEFT_PROJECT_INSTANCE = + SingleValueOptimizationRules.JoinLeftSingleValueRuleWithExprConfig.DEFAULT.toRule(); + + public static final RelOptRule JOIN_RIGHT_PROJECT_INSTANCE = + SingleValueOptimizationRules.JoinRightSingleValueRuleWithExprConfig.DEFAULT.toRule(); + + /** + * Transformer class to transform a single value nodes on either side of the join. + * This transformer contains the common code for all the SingleValueJoin rules. + */ + private static class SingleValueRelTransformer { + + private Join join; + private RelNode relNode; + private Predicate<Join> cannotTransform; + private BiFunction<RexNode, List<RexNode>, List<RexNode>> litTransformer; + private boolean valuesAsLeftChild; + private List<RexNode> literals; + + protected SingleValueRelTransformer( + Join join, List<RexNode> rexNodes, RelNode otherNode, + Predicate<Join> nonTransformable, boolean isValuesLeftChild, + BiFunction<RexNode, List<RexNode>, List<RexNode>> litTransformer) { + this.relNode = otherNode; Review Comment: @macroguo-ghy sorry didn't quite get this. If the parameters don't match then it will result in compilation failure right? -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
