/*
 * 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
 *
 *     https://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.avro.io;

import java.io.ByteArrayOutputStream;
import java.io.IOException;

import org.apache.avro.Schema;

/**
 * Write data of a schema.
 * <p>
 * Implemented for different in-memory data representations.
 */
public interface DatumWriter<D> {

  /** Set the schema. */
  void setSchema(Schema schema);

  /**
   * Write a datum. Traverse the schema, depth first, writing each leaf value in
   * the schema from the datum to the output.
   */
  void write(D datum, Encoder out) throws IOException;

  /**
   * Convenience method to Write a datum to a byte array. Traverse the schema,
   * depth first, writing each leaf value in the schema from the datum to the byte
   * array.
   *
   * @param datum The datum to serialize
   * @return The serialized datum stored in an array of bytes
   */
  default byte[] toByteArray(D datum) throws IOException {
    try (ByteArrayOutputStream out = new ByteArrayOutputStream(128)) {
      write(datum, EncoderFactory.get().directBinaryEncoder(out, null));
      return out.toByteArray();
    }
  }
}
