exec/java-exec/src/main/java/org/apache/drill/exec/physical/base/AbstractSubScan.java

/*
 * 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.drill.exec.physical.base;

import java.util.Collections;
import java.util.Iterator;
import java.util.List;

import org.apache.drill.common.exceptions.ExecutionSetupException;
import org.apache.drill.common.graph.GraphVisitor;
import org.apache.drill.exec.record.BatchSchema.SelectionVectorMode;

public abstract class AbstractSubScan extends AbstractBase implements SubScan {

  public AbstractSubScan(String userName) {
    super(userName);
  }

  @Override
  public boolean isExecutable() {
    return true;
  }

  @Override
  public <T, X, E extends Throwable> T accept(PhysicalVisitor<T, X, E> physicalVisitor, X value) throws E {
    return physicalVisitor.visitSubScan(this, value);
  }

  @Override
  public PhysicalOperator getNewWithChildren(List<PhysicalOperator> children) throws ExecutionSetupException {
    assert children == null || children.isEmpty();
    return this;
  }

  @Override
  public void accept(GraphVisitor<PhysicalOperator> visitor) {
    visitor.enter(this);
    visitor.visit(this);
    visitor.leave(this);
  }

  @Override
  public Iterator<PhysicalOperator> iterator() {
    return Collections.emptyIterator();
  }

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