org.apache.flink.table.planner.plan.nodes.logical.FlinkLogicalOverAggregate.scala Maven / Gradle / Ivy

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 * 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
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 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
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package org.apache.flink.table.planner.plan.nodes.logical

import org.apache.flink.table.api.ValidationException
import org.apache.flink.table.planner.plan.nodes.FlinkConventions

import org.apache.calcite.plan._
import org.apache.calcite.rel.`type`.RelDataType
import org.apache.calcite.rel.convert.ConverterRule
import org.apache.calcite.rel.core.Window
import org.apache.calcite.rel.logical.LogicalWindow
import org.apache.calcite.rel.metadata.RelMdCollation
import org.apache.calcite.rel.{RelCollation, RelCollationTraitDef, RelNode}
import org.apache.calcite.rex.RexLiteral
import org.apache.calcite.sql.SqlRankFunction

import java.util
import java.util.function.Supplier
import java.util.{List => JList}

import scala.collection.JavaConversions._

/**
  * Sub-class of [[Window]] that is a relational expression
  * which represents a set of over window aggregates in Flink.
  */
class FlinkLogicalOverAggregate(
    cluster: RelOptCluster,
    traitSet: RelTraitSet,
    input: RelNode,
    windowConstants: JList[RexLiteral],
    rowType: RelDataType,
    windowGroups: JList[Window.Group])
  extends Window(cluster, traitSet, input, windowConstants, rowType, windowGroups)
  with FlinkLogicalRel {

  override def copy(traitSet: RelTraitSet, inputs: JList[RelNode]): RelNode = {
    new FlinkLogicalOverAggregate(
      cluster,
      traitSet,
      inputs.get(0),
      windowConstants,
      getRowType,
      windowGroups)
  }

}

class FlinkLogicalOverAggregateConverter
  extends ConverterRule(
    classOf[LogicalWindow],
    Convention.NONE,
    FlinkConventions.LOGICAL,
    "FlinkLogicalOverAggregateConverter") {

  override def convert(rel: RelNode): RelNode = {
    val window = rel.asInstanceOf[LogicalWindow]
    val mq = rel.getCluster.getMetadataQuery
    val traitSet = rel.getCluster.traitSetOf(FlinkConventions.LOGICAL).replaceIfs(
      RelCollationTraitDef.INSTANCE, new Supplier[util.List[RelCollation]]() {
        def get: util.List[RelCollation] = {
          RelMdCollation.window(mq, window.getInput(), window.groups)
        }
      }).simplify()
    val newInput = RelOptRule.convert(window.getInput, FlinkConventions.LOGICAL)

    window.groups.foreach { group =>
      val orderKeySize = group.orderKeys.getFieldCollations.size()
      group.aggCalls.foreach { winAggCall =>
        if (orderKeySize == 0 && winAggCall.op.isInstanceOf[SqlRankFunction]) {
          throw new ValidationException("Over Agg: The window rank function without order by. " +
            "please re-check the over window statement.")
        }
      }
    }

    new FlinkLogicalOverAggregate(
      rel.getCluster,
      traitSet,
      newInput,
      window.constants,
      window.getRowType,
      window.groups)
  }
}

object FlinkLogicalOverAggregate {
  val CONVERTER = new FlinkLogicalOverAggregateConverter
}