flink-libraries/flink-table/src/main/scala/org/apache/flink/table/plan/nodes/logical/FlinkLogicalCalc.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
 *
 * 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
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package org.apache.flink.table.plan.nodes.logical

import org.apache.calcite.plan._
import org.apache.calcite.rel.RelNode
import org.apache.calcite.rel.convert.ConverterRule
import org.apache.calcite.rel.core.Calc
import org.apache.calcite.rel.logical.LogicalCalc
import org.apache.calcite.rel.metadata.RelMetadataQuery
import org.apache.calcite.rex.RexProgram
import org.apache.flink.table.plan.nodes.{CommonCalc, FlinkConventions}

class FlinkLogicalCalc(
    cluster: RelOptCluster,
    traitSet: RelTraitSet,
    input: RelNode,
    calcProgram: RexProgram)
  extends Calc(cluster, traitSet, input, calcProgram)
  with FlinkLogicalRel
  with CommonCalc {

  override def copy(traitSet: RelTraitSet, child: RelNode, program: RexProgram): Calc = {
    new FlinkLogicalCalc(cluster, traitSet, child, program)
  }

  override def computeSelfCost(planner: RelOptPlanner, mq: RelMetadataQuery): RelOptCost = {
    val child = this.getInput
    val rowCnt = mq.getRowCount(child)
    computeSelfCost(calcProgram, planner, rowCnt)
  }

  override def estimateRowCount(metadata: RelMetadataQuery): Double = {
    val child = this.getInput
    val rowCnt = metadata.getRowCount(child)
    estimateRowCount(calcProgram, rowCnt)
  }
}

private class FlinkLogicalCalcConverter
  extends ConverterRule(
    classOf[LogicalCalc],
    Convention.NONE,
    FlinkConventions.LOGICAL,
    "FlinkLogicalCalcConverter") {

  override def convert(rel: RelNode): RelNode = {
    val calc = rel.asInstanceOf[LogicalCalc]
    val traitSet = rel.getTraitSet.replace(FlinkConventions.LOGICAL)
    val newInput = RelOptRule.convert(calc.getInput, FlinkConventions.LOGICAL)

    new FlinkLogicalCalc(rel.getCluster, traitSet, newInput, calc.getProgram)
  }
}

object FlinkLogicalCalc {
  val CONVERTER: ConverterRule = new FlinkLogicalCalcConverter()
}