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 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
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 *
 * http://www.apache.org/licenses/LICENSE-2.0
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package org.apache.drill.exec.planner.physical;

import java.io.IOException;
import java.util.List;

import org.apache.drill.exec.physical.base.PhysicalOperator;
import org.apache.drill.exec.physical.config.BroadcastExchange;
import org.apache.drill.exec.physical.config.SelectionVectorRemover;
import org.apache.drill.exec.planner.cost.DrillCostBase;
import org.apache.drill.exec.record.BatchSchema.SelectionVectorMode;
import org.eigenbase.rel.RelNode;
import org.eigenbase.rel.metadata.RelMetadataQuery;
import org.eigenbase.relopt.RelOptCluster;
import org.eigenbase.relopt.RelOptCost;
import org.eigenbase.relopt.RelOptPlanner;
import org.eigenbase.relopt.RelTraitSet;

public class BroadcastExchangePrel extends ExchangePrel{

  public BroadcastExchangePrel(RelOptCluster cluster, RelTraitSet traitSet, RelNode input) {
    super(cluster, traitSet, input);
    assert input.getConvention() == Prel.DRILL_PHYSICAL;
  }

  /**
   * In a BroadcastExchange, each sender is sending data to N receivers (for costing
   * purposes we assume it is also sending to itself).
   */
  @Override
  public RelOptCost computeSelfCost(RelOptPlanner planner) {
    if(PrelUtil.getSettings(getCluster()).useDefaultCosting()) {
      return super.computeSelfCost(planner).multiplyBy(.1);
    }

    RelNode child = this.getChild();

    double inputRows = RelMetadataQuery.getRowCount(child);
    int  rowWidth = child.getRowType().getFieldCount() * DrillCostBase.AVG_FIELD_WIDTH;
    double cpuCost = DrillCostBase.SVR_CPU_COST * inputRows ;
    int numEndPoints = PrelUtil.getSettings(getCluster()).numEndPoints();
    double networkCost = DrillCostBase.BYTE_NETWORK_COST * inputRows * rowWidth * numEndPoints;
    return new DrillCostBase(inputRows, cpuCost, 0, networkCost);
  }

  @Override
  public SelectionVectorMode getEncoding() {
    return SelectionVectorMode.NONE;
  }

  @Override
  public SelectionVectorMode[] getSupportedEncodings() {
    return SelectionVectorMode.DEFAULT;
  }

  @Override
  public RelNode copy(RelTraitSet traitSet, List<RelNode> inputs) {
    return new BroadcastExchangePrel(getCluster(), traitSet, sole(inputs));
  }

  public PhysicalOperator getPhysicalOperator(PhysicalPlanCreator creator) throws IOException {
    Prel child = (Prel) this.getChild();

    PhysicalOperator childPOP = child.getPhysicalOperator(creator);

    //Currently, only accepts "NONE". For other, requires SelectionVectorRemover
    if (!childPOP.getSVMode().equals(SelectionVectorMode.NONE)) {
      childPOP = new SelectionVectorRemover(childPOP);
    }

    BroadcastExchange g = new BroadcastExchange(childPOP);
    return creator.addMetadata(this, g);
  }

}