org.apache.hadoop.hive.ql.parse.UnionProcessor Maven / Gradle / Ivy

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/*
 * 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.hadoop.hive.ql.parse;

import java.util.Stack;

import com.facebook.presto.hive.$internal.org.slf4j.Logger;
import com.facebook.presto.hive.$internal.org.slf4j.LoggerFactory;
import org.apache.hadoop.hive.ql.exec.UnionOperator;
import org.apache.hadoop.hive.ql.lib.Node;
import org.apache.hadoop.hive.ql.lib.NodeProcessor;
import org.apache.hadoop.hive.ql.lib.NodeProcessorCtx;

/**
 * FileSinkProcessor is a simple rule to remember seen unions for later
 * processing.
 *
 */
public class UnionProcessor implements NodeProcessor {

  static final private Logger LOG = LoggerFactory.getLogger(UnionProcessor.class.getName());

  @Override
  public Object process(Node nd, Stack stack, NodeProcessorCtx procCtx, Object... nodeOutputs)
      throws SemanticException {
    GenTezProcContext context = (GenTezProcContext) procCtx;
    UnionOperator union = (UnionOperator) nd;

    // simply need to remember that we've seen a union.
    context.currentUnionOperators.add(union);
    return null;
  }
}