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.connect.mirror;
  
  import org.apache.kafka.clients.consumer.ConsumerRecord;
  import org.apache.kafka.common.protocol.types.Field;
  import org.apache.kafka.common.protocol.types.Schema;
  import org.apache.kafka.common.protocol.types.Struct;
  import org.apache.kafka.common.protocol.types.Type;
  
  import java.nio.ByteBuffer;
  import java.util.HashMap;
  import java.util.Map;
  
  /**
   * Heartbeat records emitted by MirrorHeartbeatConnector.
   */
  public class Heartbeat {
      public static final String SOURCE_CLUSTER_ALIAS_KEY = "sourceClusterAlias";
      public static final String TARGET_CLUSTER_ALIAS_KEY = "targetClusterAlias";
      public static final String TIMESTAMP_KEY = "timestamp";
      public static final String VERSION_KEY = "version";
      public static final short VERSION = 0;
  
      public static final Schema VALUE_SCHEMA_V0 = new Schema(
              new Field(TIMESTAMP_KEY, Type.INT64));
  
      public static final Schema KEY_SCHEMA = new Schema(
              new Field(SOURCE_CLUSTER_ALIAS_KEY, Type.STRING),
              new Field(TARGET_CLUSTER_ALIAS_KEY, Type.STRING));
  
      public static final Schema HEADER_SCHEMA = new Schema(
              new Field(VERSION_KEY, Type.INT16));
  
      private final String sourceClusterAlias;
      private final String targetClusterAlias;
      private final long timestamp;
  
      public Heartbeat(String sourceClusterAlias, String targetClusterAlias, long timestamp) {
          this.sourceClusterAlias = sourceClusterAlias;
          this.targetClusterAlias = targetClusterAlias;
          this.timestamp = timestamp;
      }
  
      public String sourceClusterAlias() {
          return sourceClusterAlias;
      }
  
      public String targetClusterAlias() {
          return targetClusterAlias;
      }
  
      public long timestamp() {
          return timestamp;
      }
  
      @Override
      public String toString() {
          return String.format("Heartbeat{sourceClusterAlias=%s, targetClusterAlias=%s, timestamp=%d}",
              sourceClusterAlias, targetClusterAlias, timestamp);
      }
  
      ByteBuffer serializeValue(short version) {
          Schema valueSchema = valueSchema(version);
          Struct header = headerStruct(version);
          Struct value = valueStruct(valueSchema);
          ByteBuffer buffer = ByteBuffer.allocate(HEADER_SCHEMA.sizeOf(header) + valueSchema.sizeOf(value));
          HEADER_SCHEMA.write(buffer, header);
          valueSchema.write(buffer, value);
          buffer.flip();
          return buffer;
      }
  
      ByteBuffer serializeKey() {
          Struct struct = keyStruct();
          ByteBuffer buffer = ByteBuffer.allocate(KEY_SCHEMA.sizeOf(struct));
          KEY_SCHEMA.write(buffer, struct);
          buffer.flip();
          return buffer;
      }
  
      public static Heartbeat deserializeRecord(ConsumerRecord<byte[], byte[]> record) {
          ByteBuffer value = ByteBuffer.wrap(record.value());
          Struct headerStruct = HEADER_SCHEMA.read(value);
          short version = headerStruct.getShort(VERSION_KEY);
          Struct valueStruct = valueSchema(version).read(value);
          long timestamp = valueStruct.getLong(TIMESTAMP_KEY);
          Struct keyStruct = KEY_SCHEMA.read(ByteBuffer.wrap(record.key()));
          String sourceClusterAlias = keyStruct.getString(SOURCE_CLUSTER_ALIAS_KEY);
          String targetClusterAlias = keyStruct.getString(TARGET_CLUSTER_ALIAS_KEY); 
          return new Heartbeat(sourceClusterAlias, targetClusterAlias, timestamp);    
      } 
  
      private Struct headerStruct(short version) {
          Struct struct = new Struct(HEADER_SCHEMA);
          struct.set(VERSION_KEY, version);
          return struct;
      }
  
      private Struct valueStruct(Schema schema) {
          Struct struct = new Struct(schema);
          struct.set(TIMESTAMP_KEY, timestamp);
          return struct;
      }
  
      private Struct keyStruct() {
          Struct struct = new Struct(KEY_SCHEMA);
          struct.set(SOURCE_CLUSTER_ALIAS_KEY, sourceClusterAlias);
          struct.set(TARGET_CLUSTER_ALIAS_KEY, targetClusterAlias);
          return struct;
      }
  
      Map<String, ?> connectPartition() {
          Map<String, Object> partition = new HashMap<>();
          partition.put(SOURCE_CLUSTER_ALIAS_KEY, sourceClusterAlias);
          partition.put(TARGET_CLUSTER_ALIAS_KEY, targetClusterAlias);
          return partition;
      }
  
      byte[] recordKey() {
          return serializeKey().array();
      }
  
      byte[] recordValue() {
          return serializeValue(VERSION).array();
      }
  
      private static Schema valueSchema(short version) {
          assert version == 0;
          return VALUE_SCHEMA_V0;
      }
  }
  