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.jdbc.consumer;
  
  import java.math.BigDecimal;
  import java.math.RoundingMode;
  import java.sql.ResultSet;
  import java.sql.SQLException;
  import org.apache.arrow.vector.DecimalVector;
  
  /**
   * Consumer which consume decimal type values from {@link ResultSet}. Write the data to {@link
   * org.apache.arrow.vector.DecimalVector}.
   */
  public abstract class DecimalConsumer extends BaseConsumer<DecimalVector> {
    private final RoundingMode bigDecimalRoundingMode;
    private final int scale;
  
    /**
     * Constructs a new consumer.
     *
     * @param vector the underlying vector for the consumer.
     * @param index the column id for the consumer.
     */
    public DecimalConsumer(DecimalVector vector, int index) {
      this(vector, index, null);
    }
  
    /**
     * Constructs a new consumer, with optional coercibility.
     *
     * @param vector the underlying vector for the consumer.
     * @param index the column index for the consumer.
     * @param bigDecimalRoundingMode java.math.RoundingMode to be applied if the BigDecimal scale does
     *     not match that of the target vector. Set to null to retain strict matching behavior (scale
     *     of source and target vector must match exactly).
     */
    public DecimalConsumer(DecimalVector vector, int index, RoundingMode bigDecimalRoundingMode) {
      super(vector, index);
      this.bigDecimalRoundingMode = bigDecimalRoundingMode;
      this.scale = vector.getScale();
    }
  
    /** Creates a consumer for {@link DecimalVector}. */
    public static JdbcConsumer<DecimalVector> createConsumer(
        DecimalVector vector, int index, boolean nullable, RoundingMode bigDecimalRoundingMode) {
      if (nullable) {
        return new NullableDecimalConsumer(vector, index, bigDecimalRoundingMode);
      } else {
        return new NonNullableDecimalConsumer(vector, index, bigDecimalRoundingMode);
      }
    }
  
    protected void set(BigDecimal value) {
      if (bigDecimalRoundingMode != null && value.scale() != scale) {
        value = value.setScale(scale, bigDecimalRoundingMode);
      }
      vector.set(currentIndex, value);
    }
  
    /** Consumer for nullable decimal. */
    static class NullableDecimalConsumer extends DecimalConsumer {
  
      /** Instantiate a DecimalConsumer. */
      public NullableDecimalConsumer(
          DecimalVector vector, int index, RoundingMode bigDecimalRoundingMode) {
        super(vector, index, bigDecimalRoundingMode);
      }
  
      @Override
      public void consume(ResultSet resultSet) throws SQLException {
        BigDecimal value = resultSet.getBigDecimal(columnIndexInResultSet);
        if (!resultSet.wasNull()) {
          // for fixed width vectors, we have allocated enough memory proactively,
          // so there is no need to call the setSafe method here.
          set(value);
        }
        currentIndex++;
      }
    }
  
    /** Consumer for non-nullable decimal. */
    static class NonNullableDecimalConsumer extends DecimalConsumer {
  
      /** Instantiate a DecimalConsumer. */
      public NonNullableDecimalConsumer(
          DecimalVector vector, int index, RoundingMode bigDecimalRoundingMode) {
        super(vector, index, bigDecimalRoundingMode);
      }
  
      @Override
      public void consume(ResultSet resultSet) throws SQLException {
        BigDecimal value = resultSet.getBigDecimal(columnIndexInResultSet);
        // for fixed width vectors, we have allocated enough memory proactively,
        // so there is no need to call the setSafe method here.
        set(value);
        currentIndex++;
      }
    }
  }
  