flink-libraries/flink-table/src/main/scala/org/apache/flink/table/plan/metadata/FlinkRelMdCumulativeCost.scala

/*
 * 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
 *
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package org.apache.flink.table.plan.metadata

import org.apache.calcite.adapter.enumerable.EnumerableInterpreter
import org.apache.calcite.plan.RelOptCost
import org.apache.calcite.rel.RelNode
import org.apache.calcite.rel.metadata._
import org.apache.calcite.util.BuiltInMethod

import scala.collection.JavaConversions._

class FlinkRelMdCumulativeCost private extends MetadataHandler[BuiltInMetadata.CumulativeCost] {

  def getDef: MetadataDef[BuiltInMetadata.CumulativeCost] = BuiltInMetadata.CumulativeCost.DEF

  def getCumulativeCost(rel: RelNode, mq: RelMetadataQuery): RelOptCost = {
    rel.getInputs.foldLeft(mq.getNonCumulativeCost(rel))((acc, r) => {
      acc.plus(mq.getCumulativeCost(r))})
  }

  def getCumulativeCost(
    rel: EnumerableInterpreter,
    mq: RelMetadataQuery): RelOptCost = mq.getNonCumulativeCost(rel)

}

object FlinkRelMdCumulativeCost {

  private val INSTANCE = new FlinkRelMdCumulativeCost

  val SOURCE: RelMetadataProvider = ReflectiveRelMetadataProvider.reflectiveSource(
    BuiltInMethod.CUMULATIVE_COST.method, INSTANCE)

}