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 accord;
  
  import accord.local.Node.Id;
  import accord.messages.Message;
  import com.google.common.collect.ImmutableSet;
  import com.google.common.collect.Sets;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.util.Set;
  import java.util.function.Predicate;
  
  public class NetworkFilter
  {
      private final Logger logger = LoggerFactory.getLogger(NetworkFilter.class);
  
      private interface DiscardPredicate
      {
          boolean check(Id from, Id to, Message message);
      }
  
      Set<DiscardPredicate> discardPredicates = Sets.newConcurrentHashSet();
  
      public boolean shouldDiscard(Id from, Id to, Message message)
      {
          return discardPredicates.stream().anyMatch(p -> p.check(from, to, message));
      }
  
      public void isolate(Id node)
      {
          logger.info("Isolating node {}", node);
          discardPredicates.add((from, to, msg) -> from.equals(node) || to.equals(node));
      }
  
      public void isolate(Iterable<Id> ids)
      {
          for (Id id : ids)
              isolate(id);
      }
  
      public static Predicate<Id> anyId()
      {
          return id -> true;
      }
  
      public static Predicate<Id> isId(Iterable<Id> ids)
      {
          return ImmutableSet.copyOf(ids)::contains;
      }
  
      public static Predicate<Message> isMessageType(Class<? extends Message> klass)
      {
          return msg -> klass.isAssignableFrom(msg.getClass());
      }
  
      public static Predicate<Message> notMessageType(Class<? extends Message> klass)
      {
          return msg -> !klass.isAssignableFrom(msg.getClass());
      }
  
      /**
       * message will be discarded if all predicates apply
       */
      public void addFilter(Predicate<Id> fromPredicate, Predicate<Id> toPredicate, Predicate<Message> messagePredicate)
      {
          discardPredicates.add((from, to, msg) -> fromPredicate.test(from) && toPredicate.test(to) && messagePredicate.test(msg));
      }
  
      public void clear()
      {
          logger.info("Clearing network filters");
          discardPredicates.clear();
      }
  }
  