content: /*
   * 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.calcite.adapter.arrow;
  
  import org.apache.calcite.plan.RelOptCluster;
  import org.apache.calcite.plan.RelOptCost;
  import org.apache.calcite.plan.RelOptPlanner;
  import org.apache.calcite.plan.RelTraitSet;
  import org.apache.calcite.rel.RelNode;
  import org.apache.calcite.rel.core.Filter;
  import org.apache.calcite.rel.metadata.RelMetadataQuery;
  import org.apache.calcite.rex.RexNode;
  
  import java.util.List;
  
  import static java.util.Objects.requireNonNull;
  
  /**
   * Implementation of a {@link org.apache.calcite.rel.core.Filter}
   * relational expression in Arrow.
   */
  class ArrowFilter extends Filter implements ArrowRel {
    private final List<String> match;
  
    ArrowFilter(RelOptCluster cluster, RelTraitSet traitSet, RelNode input, RexNode condition) {
      super(cluster, traitSet, input, condition);
      final ArrowTranslator translator =
          ArrowTranslator.create(cluster.getRexBuilder(), input.getRowType());
      this.match = translator.translateMatch(condition);
  
      assert getConvention() == ArrowRel.CONVENTION;
      assert getConvention() == input.getConvention();
    }
  
    @Override public RelOptCost computeSelfCost(RelOptPlanner planner, RelMetadataQuery mq) {
      final RelOptCost cost = super.computeSelfCost(planner, mq);
      return requireNonNull(cost, "cost").multiplyBy(0.1);
    }
  
    @Override public ArrowFilter copy(RelTraitSet traitSet, RelNode input, RexNode condition) {
      return new ArrowFilter(getCluster(), traitSet, input, condition);
    }
  
    @Override public void implement(Implementor implementor) {
      implementor.visitInput(0, getInput());
      implementor.addFilters(match);
    }
  }
  