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.cassandra.distributed.impl;
  
  import java.util.function.Consumer;
  
  import org.apache.cassandra.diag.DiagnosticEventService;
  import org.apache.cassandra.distributed.api.IListen;
  import org.apache.cassandra.gms.GossiperEvent;
  import org.apache.cassandra.schema.SchemaEvent;
  
  public class Listen implements IListen
  {
      public Cancel schema(Runnable onChange)
      {
          Consumer<SchemaEvent> consumer = event -> onChange.run();
          DiagnosticEventService.instance().subscribe(SchemaEvent.class, SchemaEvent.SchemaEventType.VERSION_UPDATED, consumer);
          return () -> DiagnosticEventService.instance().unsubscribe(SchemaEvent.class, consumer);
      }
  
      public Cancel liveMembers(Runnable onChange)
      {
          Consumer<GossiperEvent> consumer = event -> onChange.run();
          DiagnosticEventService.instance().subscribe(GossiperEvent.class, GossiperEvent.GossiperEventType.REAL_MARKED_ALIVE, consumer);
          return () -> DiagnosticEventService.instance().unsubscribe(GossiperEvent.class, consumer);
      }
  }
  