lincoln-lil commented on code in PR #20359: URL: https://github.com/apache/flink/pull/20359#discussion_r938431641
########## flink-table/flink-table-planner/src/main/scala/org/apache/flink/table/planner/plan/optimize/JoinHintResolver.scala: ########## @@ -0,0 +1,211 @@ +/* + * 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.flink.table.planner.plan.optimize + +import org.apache.flink.table.api.ValidationException +import org.apache.flink.table.planner.JHashSet +import org.apache.flink.table.planner.hint.{FlinkHints, JoinStrategy} + +import org.apache.calcite.plan.hep.HepRelVertex +import org.apache.calcite.plan.volcano.RelSubset +import org.apache.calcite.rel.{BiRel, RelNode, RelShuttleImpl} +import org.apache.calcite.rel.core.TableScan +import org.apache.calcite.rel.hint.{Hintable, RelHint} +import org.apache.calcite.rel.logical.{LogicalCorrelate, LogicalJoin} +import org.apache.calcite.util.Util + +import java.util.Collections + +import scala.collection.JavaConversions._ + +/** + * Resolve and validate Hints, currently only join hints are supported. + * + * Here the duplicated join hints will not be checked. + */ +class JoinHintResolver { + + private val allHints = new JHashSet[RelHint] + private val validHints = new JHashSet[RelHint] + + /** Transforms a relational expression into another relational expression. */ + def resolve(roots: Seq[RelNode]): Seq[RelNode] = { + val resolvedRoots = roots.map(node => node.accept(new JoinHintResolver)) + // check if invalid hints exist + validateHints() + resolvedRoots + } + + class JoinHintResolver extends RelShuttleImpl { + + override def visit(correlate: LogicalCorrelate): RelNode = { + visitBiRel(correlate) + } + + override def visit(join: LogicalJoin): RelNode = { + visitBiRel(join) + } + + private def visitBiRel(biRel: BiRel): RelNode = { + val leftName = extractAliasOrTableName(biRel.getLeft) + val rightName = extractAliasOrTableName(biRel.getRight) + + val existentKVHints = new JHashSet[RelHint] + + val newHints = biRel + .asInstanceOf[Hintable] + .getHints + .flatMap( + h => + if (JoinStrategy.isJoinStrategy(h.hintName)) { + allHints.add(trimInheritPath(h)) + // if the hint is valid + val newOptions = h.listOptions + .map( + option => { + if ( + leftName.isDefined + && rightName.isDefined + && matchIdentifier(option, leftName.get) + && matchIdentifier(option, rightName.get) + ) { + throw new ValidationException( + String.format( + "Ambitious option: %s in hint: %s, the input " + + "relations are: %s, %s", + option, + h, + leftName, + rightName)) + } else if (leftName.isDefined && matchIdentifier(option, leftName.get)) { + JoinStrategy.LEFT_INPUT + } else if (rightName.isDefined && matchIdentifier(option, rightName.get)) { + JoinStrategy.RIGHT_INPUT + } else { + "" + } + }) + .filter(p => p.nonEmpty) + // check whether the join hints options are valid + val isValidOption = JoinStrategy.validOptions(h.hintName, newOptions) + if (isValidOption) { + validHints.add(trimInheritPath(h)) + List( + RelHint + .builder(h.hintName) + // if the hint defines more than one args, only retain the first one + .hintOptions(Collections.singletonList(newOptions.head)) + .build()) + } else { + // invalid hint + List() + } + } else { + if (existentKVHints.contains(h)) { + List() + } else { + existentKVHints.add(h) + List(h) + } + }) + .filter(p => { !(p.kvOptions.isEmpty && p.listOptions.isEmpty) }) + val newNode = super.visitChildren(biRel) + if (biRel.asInstanceOf[Hintable].getHints.nonEmpty) { + // replace the table name as LEFT or RIGHT + newNode.asInstanceOf[Hintable].withHints(newHints) + } else { + // has no hints, return original node directly. + newNode + } + } + + private def trimInheritPath(hint: RelHint): RelHint = { + val builder = RelHint.builder(hint.hintName) + if (hint.listOptions.nonEmpty) { + builder.hintOptions(hint.listOptions).build() + } else { + builder.hintOptions(hint.kvOptions).build() + } + } + } + + private def validateHints(): Unit = { + val invalidHints = allHints.diff(validHints) + if (invalidHints.nonEmpty) { + val msg = invalidHints.foldLeft("")( + (msg, hint) => + msg + "\n`" + hint.hintName + + "(" + hint.listOptions.mkString(", ") + ")`") + throw new ValidationException( + String.format( + "The options of following hints cannot match the name of " + + "input tables or views: %s", + msg)) + } + } + + def extractAliasOrTableName(node: RelNode): Option[String] = { + // check whether the input relation is converted from a view + val aliasName = FlinkHints.getTableAlias(node) + if (aliasName.isPresent) { + return Some(aliasName.get()) + } + // otherwise, the option may be a table name + val tableScan = getTableScan(node) + if (tableScan.isDefined) { + val tableName = FlinkHints.getTableName(tableScan.get.getTable) + if (tableName.isPresent) { + return Some(tableName.get()) + } + } + + None + } + + @scala.annotation.tailrec + private def getTableScan(node: RelNode): Option[TableScan] = { + node match { + case tableScan: TableScan => Some(tableScan) + case node => + if (FlinkHints.canTransposeToTableScan(node)) { + getTableScan(trimHep(node.getInput(0))) + } else { + None + } + } + } + + private def trimHep(node: RelNode): RelNode = { + node match { + case hepRelVertex: HepRelVertex => + hepRelVertex.getCurrentRel + case subset: RelSubset => + Util.first(subset.getBest, subset.getOriginal) + case _ => node + } + } + + /** + * Check whether the given hint option matches the table qualified names. For convenience, we + * follow a simple rule: the matching is successful if the option is the suffix of the table + * qualified names. + */ + private def matchIdentifier(option: String, tableIdentifier: String): Boolean = + tableIdentifier.toLowerCase.endsWith(option.toLowerCase) Review Comment: `endsWith` may encounter bad case, e.g., a table name 'test' with a hint value 't'. please add test case that table/alias name is a sub-string of scan table name. -- 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: issues-unsubscr...@flink.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
