pig/src/main/java/org/apache/calcite/adapter/pig/PigProject.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.calcite.adapter.pig;

import org.apache.calcite.plan.RelOptCluster;
import org.apache.calcite.plan.RelOptTable;
import org.apache.calcite.plan.RelTraitSet;
import org.apache.calcite.rel.RelNode;
import org.apache.calcite.rel.core.Project;
import org.apache.calcite.rel.type.RelDataType;
import org.apache.calcite.rex.RexNode;

import com.google.common.collect.ImmutableList;

import java.util.List;

/** Implementation of {@link org.apache.calcite.rel.core.Project} in
 * {@link PigRel#CONVENTION Pig calling convention}. */
public class PigProject extends Project implements PigRel {

  /** Creates a PigProject. */
  public PigProject(RelOptCluster cluster, RelTraitSet traitSet, RelNode input,
      List<? extends RexNode> projects, RelDataType rowType) {
    super(cluster, traitSet, ImmutableList.of(), input, projects, rowType);
    assert getConvention() == PigRel.CONVENTION;
  }

  @Override public Project copy(RelTraitSet traitSet, RelNode input, List<RexNode> projects,
      RelDataType rowType) {
    return new PigProject(input.getCluster(), traitSet, input, projects, rowType);
  }

  @Override public void implement(Implementor implementor) {
    System.out.println(getTable());
  }

  /**
   * Override this method so it looks down the tree to find the table this node
   * is acting on.
   */
  @Override public RelOptTable getTable() {
    return getInput().getTable();
  }
}