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.service.paxos;
  
  import java.util.ArrayList;
  import java.util.List;
  import java.util.Objects;
  
  import com.google.common.collect.Iterables;
  import org.junit.Assert;
  import org.junit.Test;
  
  import org.apache.cassandra.db.DecoratedKey;
  import org.apache.cassandra.dht.Murmur3Partitioner;
  import org.apache.cassandra.service.paxos.AbstractPaxosRepair.State;
  import org.apache.cassandra.utils.ByteBufferUtil;
  
  import static org.apache.cassandra.service.paxos.AbstractPaxosRepair.DONE;
  
  /**
   * test the state change logic of AbstractPaxosRepair
   */
  public class AbstractPaxosRepairTest
  {
      private static DecoratedKey dk(int k)
      {
          return Murmur3Partitioner.instance.decorateKey(ByteBufferUtil.bytes(k));
      }
  
      private static final DecoratedKey DK1 = dk(1);
  
      private static State STARTED = new State();
  
      private static class PaxosTestRepair extends AbstractPaxosRepair
      {
          public PaxosTestRepair()
          {
              super(Murmur3Partitioner.instance.decorateKey(ByteBufferUtil.bytes(1)), null, -1);
          }
  
          public State restart(State state, long waitUntil)
          {
              return STARTED;
          }
  
          public void setState(State update)
          {
              updateState(state(), null, (i1, i2) -> update);
          }
      }
  
      private static class Event
      {
          final AbstractPaxosRepair repair;
          final AbstractPaxosRepair.Result result;
  
          public Event(AbstractPaxosRepair repair, AbstractPaxosRepair.Result result)
          {
              this.repair = repair;
              this.result = result;
          }
  
          public String toString()
          {
              return "Event{" +
                     "repair=" + repair +
                     ", result=" + result +
                     '}';
          }
  
          public boolean equals(Object o)
          {
              if (this == o) return true;
              if (o == null || getClass() != o.getClass()) return false;
              Event event = (Event) o;
              return Objects.equals(repair, event.repair) && Objects.equals(result, event.result);
          }
  
          public int hashCode()
          {
              return Objects.hash(repair, result);
          }
      }
  
      private static class Listener implements AbstractPaxosRepair.Listener
      {
  
          final List<Event> events = new ArrayList<>();
  
          public void onComplete(AbstractPaxosRepair repair, AbstractPaxosRepair.Result result)
          {
              events.add(new Event(repair, result));
          }
  
          public Event getOnlyEvent()
          {
              return Iterables.getOnlyElement(events);
          }
      }
  
      @Test
      public void stateUpdate()
      {
          // listeners shoulnd't be called on state updates
          PaxosTestRepair repair = new PaxosTestRepair();
          Listener listener = new Listener();
          repair.addListener(listener);
          Assert.assertNull(repair.state());
          repair.start();
          Assert.assertSame(STARTED, repair.state());
          Assert.assertTrue(listener.events.isEmpty());
      }
  
      @Test
      public void resultUpdate()
      {
          // listeners should be called on state updates
          PaxosTestRepair repair = new PaxosTestRepair();
          Listener listener = new Listener();
          repair.addListener(listener);
          repair.start();
          Assert.assertTrue(listener.events.isEmpty());
  
          repair.setState(DONE);
          Assert.assertEquals(new Event(repair, DONE), listener.getOnlyEvent());
      }
  
      @Test
      public void stateUpdateException()
      {
          // state should be set to failure and listeners called on exception
          Throwable e = new Throwable();
  
          PaxosTestRepair repair = new PaxosTestRepair();
          Listener listener = new Listener();
          repair.addListener(listener);
          repair.start();
  
          repair.updateState(repair.state(), null, (i1, i2) -> {throw e;});
          Assert.assertEquals(new Event(repair, new AbstractPaxosRepair.Failure(e)), listener.getOnlyEvent());
  
      }
  
      @Test
      public void postResultListenerAttachment()
      {
          // listener should be called immediately if the repair is already complete
          PaxosTestRepair repair = new PaxosTestRepair();
          repair.start();
  
          repair.setState(DONE);
  
          Listener listener = new Listener();
          Assert.assertTrue(listener.events.isEmpty());
          repair.addListener(listener);
          Assert.assertEquals(new Event(repair, DONE), listener.getOnlyEvent());
      }
  }
  