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.asterix.optimizer.rules.pushdown.descriptor;
  
  import java.util.HashSet;
  import java.util.Set;
  
  import org.apache.hyracks.algebricks.core.algebra.base.ILogicalExpression;
  import org.apache.hyracks.algebricks.core.algebra.base.ILogicalOperator;
  import org.apache.hyracks.algebricks.core.algebra.base.LogicalVariable;
  
  public class UseDescriptor extends AbstractDescriptor {
      private final Set<LogicalVariable> usedVariables;
      private final LogicalVariable producedVariable;
  
      public UseDescriptor(int scope, ILogicalOperator subplanOperator, ILogicalOperator operator,
              ILogicalExpression expression, int expressionIndex, LogicalVariable producedVariable) {
          super(scope, subplanOperator, operator, expression, expressionIndex);
          this.usedVariables = new HashSet<>();
          this.producedVariable = producedVariable;
      }
  
      public Set<LogicalVariable> getUsedVariables() {
          return usedVariables;
      }
  
      public LogicalVariable getProducedVariable() {
          return producedVariable;
      }
  
      @Override
      public String toString() {
          return operator.getOperatorTag() + ": [" + expression + "]";
      }
  }
  