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.kafka.server.common.serialization;
  
  import org.apache.kafka.common.protocol.ApiMessage;
  import org.apache.kafka.common.protocol.ObjectSerializationCache;
  import org.apache.kafka.common.protocol.Readable;
  import org.apache.kafka.common.protocol.Writable;
  import org.apache.kafka.common.utils.ByteUtils;
  import org.apache.kafka.server.common.ApiMessageAndVersion;
  
  /**
   * This is an implementation of {@code RecordSerde} with {@link ApiMessageAndVersion} but implementors need to implement
   * {@link #apiMessageFor(short)} to return a {@code ApiMessage} instance for the given {@code apiKey}.
   * <br>
   * This can be used as the underlying serialization mechanism for records defined with {@link ApiMessage}s.
   * <br><br>
   * Serialization format for the given {@code ApiMessageAndVersion} is below:
   * <pre>
   *     [data_frame_version header message]
   *     header =&gt; [api_key version]
   *
   *     data_frame_version   : This is the header version, current value is 0. Header includes both api_key and version.
   *     api_key              : apiKey of {@code ApiMessageAndVersion} object.
   *     version              : version of {@code ApiMessageAndVersion} object.
   *     message              : serialized message of {@code ApiMessageAndVersion} object.
   * </pre>
   */
  public abstract class AbstractApiMessageSerde implements RecordSerde<ApiMessageAndVersion> {
      private static final short DEFAULT_FRAME_VERSION = 1;
      private static final int DEFAULT_FRAME_VERSION_SIZE = ByteUtils.sizeOfUnsignedVarint(DEFAULT_FRAME_VERSION);
  
      private static short unsignedIntToShort(Readable input, String entity) {
          int val;
          try {
              val = input.readUnsignedVarint();
          } catch (Exception e) {
              throw new MetadataParseException("Error while reading " + entity, e);
          }
          if (val > Short.MAX_VALUE) {
              throw new MetadataParseException("Value for " + entity + " was too large.");
          }
          return (short) val;
      }
  
      @Override
      public int recordSize(ApiMessageAndVersion data,
                            ObjectSerializationCache serializationCache) {
          int size = DEFAULT_FRAME_VERSION_SIZE;
          size += ByteUtils.sizeOfUnsignedVarint(data.message().apiKey());
          size += ByteUtils.sizeOfUnsignedVarint(data.version());
          size += data.message().size(serializationCache, data.version());
          return size;
      }
  
      @Override
      public void write(ApiMessageAndVersion data,
                        ObjectSerializationCache serializationCache,
                        Writable out) {
          out.writeUnsignedVarint(DEFAULT_FRAME_VERSION);
          out.writeUnsignedVarint(data.message().apiKey());
          out.writeUnsignedVarint(data.version());
          data.message().write(out, serializationCache, data.version());
      }
  
      @Override
      public ApiMessageAndVersion read(Readable input,
                                       int size) {
          short frameVersion = unsignedIntToShort(input, "frame version");
  
          if (frameVersion == 0) {
              throw new MetadataParseException("Could not deserialize metadata record with frame version 0. " +
                  "Note that upgrades from the preview release of KRaft in 2.8 to newer versions are not supported.");
          } else if (frameVersion != DEFAULT_FRAME_VERSION) {
              throw new MetadataParseException("Could not deserialize metadata record due to unknown frame version "
                      + frameVersion + "(only frame version " + DEFAULT_FRAME_VERSION + " is supported)");
          }
          short apiKey = unsignedIntToShort(input, "type");
          short version = unsignedIntToShort(input, "version");
  
          ApiMessage record;
          try {
              record = apiMessageFor(apiKey);
          } catch (Exception e) {
              throw new MetadataParseException(e);
          }
          try {
              record.read(input, version);
          } catch (Exception e) {
              throw new MetadataParseException("Failed to deserialize record with type " + apiKey, e);
          }
          if (input.remaining() > 0) {
              throw new MetadataParseException("Found " + input.remaining() +
                      " byte(s) of garbage after " + apiKey);
          }
          return new ApiMessageAndVersion(record, version);
      }
  
      /**
       * Return {@code ApiMessage} instance for the given {@code apiKey}. This is used while deserializing the bytes
       * payload into the respective {@code ApiMessage} in {@link #read(Readable, int)} method.
       *
       * @param apiKey apiKey for which a {@code ApiMessage} to be created.
       */
      public abstract ApiMessage apiMessageFor(short apiKey);
  }
  