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.arrow.adapter.avro.consumers;
  
  import java.io.IOException;
  import org.apache.arrow.util.AutoCloseables;
  import org.apache.arrow.vector.ValueVector;
  import org.apache.arrow.vector.complex.UnionVector;
  import org.apache.arrow.vector.types.Types;
  import org.apache.avro.io.Decoder;
  
  /**
   * Consumer which consume unions type values from avro decoder. Write the data to {@link
   * org.apache.arrow.vector.complex.UnionVector}.
   */
  public class AvroUnionsConsumer extends BaseAvroConsumer<UnionVector> {
  
    private Consumer[] delegates;
    private Types.MinorType[] types;
  
    /** Instantiate an AvroUnionConsumer. */
    public AvroUnionsConsumer(UnionVector vector, Consumer[] delegates, Types.MinorType[] types) {
  
      super(vector);
      this.delegates = delegates;
      this.types = types;
    }
  
    @Override
    public void consume(Decoder decoder) throws IOException {
      int fieldIndex = decoder.readInt();
  
      ensureInnerVectorCapacity(currentIndex + 1, fieldIndex);
      Consumer delegate = delegates[fieldIndex];
  
      vector.setType(currentIndex, types[fieldIndex]);
      // In UnionVector we need to set sub vector writer position before consume a value
      // because in the previous iterations we might not have written to the specific union sub
      // vector.
      delegate.setPosition(currentIndex);
      delegate.consume(decoder);
  
      currentIndex++;
    }
  
    @Override
    public void close() throws Exception {
      super.close();
      AutoCloseables.close(delegates);
    }
  
    @Override
    public boolean resetValueVector(UnionVector vector) {
      for (int i = 0; i < delegates.length; i++) {
        delegates[i].resetValueVector(vector.getChildrenFromFields().get(i));
      }
      return super.resetValueVector(vector);
    }
  
    void ensureInnerVectorCapacity(long targetCapacity, int fieldIndex) {
      ValueVector fieldVector = vector.getChildrenFromFields().get(fieldIndex);
      if (fieldVector.getMinorType() == Types.MinorType.NULL) {
        return;
      }
      while (fieldVector.getValueCapacity() < targetCapacity) {
        fieldVector.reAlloc();
      }
    }
  }
  