/*
 * 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.parquet.column.values.factory;

import org.apache.parquet.column.ColumnDescriptor;
import org.apache.parquet.column.ParquetProperties;
import org.apache.parquet.column.values.ValuesWriter;

/**
 * Can be overridden to allow users to manually test different strategies to create ValuesWriters.
 * To do this, the ValuesWriterFactory to be used must be passed to the {@link org.apache.parquet.column.ParquetProperties.Builder}.
 * <p>
 * Lifecycle of ValuesWriterFactories is:
 * <ul>
 * <li> Initialized while creating a {@link org.apache.parquet.column.ParquetProperties} using the Builder</li>
 * <li> If the factory must read Hadoop config, it needs to implement the Configurable interface.
 * In addition to that, ParquetOutputFormat needs to be updated to pass in the Hadoop config via the setConf()
 * method on the Configurable interface.</li>
 * <li> newValuesWriter is called once per column for every block of data.</li>
 * </ul>
 */
public interface ValuesWriterFactory {

  /**
   * Used to initialize the factory. This method is called before newValuesWriter()
   *
   * @param parquetProperties a write configuration
   */
  void initialize(ParquetProperties parquetProperties);

  /**
   * Creates a ValuesWriter to write values for the given column.
   *
   * @param descriptor a column descriptor
   * @return a new values writer for values in the descriptor's column
   */
  ValuesWriter newValuesWriter(ColumnDescriptor descriptor);
}
