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.vector.FieldVector;
  import org.apache.avro.io.Decoder;
  
  /**
   * Consumer wrapper which consumes nullable type values from avro decoder. Write the data to the
   * underlying {@link FieldVector}.
   *
   * @param <T> The vector within consumer or its delegate.
   */
  public class AvroNullableConsumer<T extends FieldVector> extends BaseAvroConsumer<T> {
  
    private final Consumer<T> delegate;
    private final int nullIndex;
  
    /** Instantiate a AvroNullableConsumer. */
    @SuppressWarnings("unchecked")
    public AvroNullableConsumer(Consumer<T> delegate, int nullIndex) {
      super((T) delegate.getVector());
      this.delegate = delegate;
      this.nullIndex = nullIndex;
    }
  
    @Override
    public void consume(Decoder decoder) throws IOException {
      int typeIndex = decoder.readInt();
      if (typeIndex == nullIndex) {
        decoder.readNull();
        delegate.addNull();
      } else {
        delegate.consume(decoder);
      }
      currentIndex++;
    }
  
    @Override
    public void addNull() {
      // Can be called by containers of nullable types
      delegate.addNull();
      currentIndex++;
    }
  
    @Override
    public void setPosition(int index) {
      if (index < 0 || index > vector.getValueCount()) {
        throw new IllegalArgumentException("Index out of bounds");
      }
      delegate.setPosition(index);
      super.setPosition(index);
    }
  
    @Override
    public boolean resetValueVector(T vector) {
      boolean delegateOk = delegate.resetValueVector(vector);
      boolean thisOk = super.resetValueVector(vector);
      return thisOk && delegateOk;
    }
  
    @Override
    public void close() throws Exception {
      super.close();
      delegate.close();
    }
  }
  