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.topology;
  
  import accord.local.Node;
  import accord.utils.SortedArrays.SortedArrayList;
  
  import org.junit.jupiter.api.Assertions;
  import org.junit.jupiter.api.Test;
  
  import java.util.HashSet;
  import java.util.Set;
  
  import static accord.Utils.ids;
  import static accord.impl.IntKey.range;
  
  public class ShardTest
  {
      @Test
      void toleratedFailures()
      {
          Assertions.assertEquals(0, Shard.maxToleratedFailures(1));
          Assertions.assertEquals(0, Shard.maxToleratedFailures(2));
          Assertions.assertEquals(1, Shard.maxToleratedFailures(3));
          Assertions.assertEquals(1, Shard.maxToleratedFailures(4));
          Assertions.assertEquals(2, Shard.maxToleratedFailures(5));
          Assertions.assertEquals(2, Shard.maxToleratedFailures(6));
          Assertions.assertEquals(3, Shard.maxToleratedFailures(7));
          Assertions.assertEquals(3, Shard.maxToleratedFailures(8));
          Assertions.assertEquals(4, Shard.maxToleratedFailures(9));
          Assertions.assertEquals(4, Shard.maxToleratedFailures(10));
          Assertions.assertEquals(5, Shard.maxToleratedFailures(11));
          Assertions.assertEquals(5, Shard.maxToleratedFailures(12));
          Assertions.assertEquals(6, Shard.maxToleratedFailures(13));
          Assertions.assertEquals(6, Shard.maxToleratedFailures(14));
          Assertions.assertEquals(7, Shard.maxToleratedFailures(15));
          Assertions.assertEquals(7, Shard.maxToleratedFailures(16));
          Assertions.assertEquals(8, Shard.maxToleratedFailures(17));
          Assertions.assertEquals(8, Shard.maxToleratedFailures(18));
          Assertions.assertEquals(9, Shard.maxToleratedFailures(19));
          Assertions.assertEquals(9, Shard.maxToleratedFailures(20));
      }
  
      void assertSimpleFastQuorumSize(int expected, int replicas, int fpElectorate)
      {
          int f = Shard.maxToleratedFailures(replicas);
          int actual = Shard.simpleFastQuorumSize(replicas, fpElectorate, replicas - f);
          Assertions.assertEquals(expected, actual);
      }
  
      void assertIllegalArgument(Runnable runnable, String msg)
      {
          try
          {
              runnable.run();
              Assertions.fail(msg);
          }
          catch (IllegalArgumentException e)
          {
              // noop
          }
      }
  
      void assertInvalidFastPathElectorateSize(int replicas, int fpElectorate)
      {
          int f = Shard.maxToleratedFailures(replicas);
          assertIllegalArgument(() -> Shard.simpleFastQuorumSize(replicas, fpElectorate, replicas - f),
                                String.format("Expected exception for fp electorate size %s for replica set size %s (f %s)",
                                              fpElectorate, replicas, f));
      }
  
      @Test
      void slowQuorumSizeTest()
      {
          Assertions.assertEquals(1, Shard.slowQuorumSize(1));
          Assertions.assertEquals(2, Shard.slowQuorumSize(2));
          Assertions.assertEquals(2, Shard.slowQuorumSize(3));
          Assertions.assertEquals(3, Shard.slowQuorumSize(4));
          Assertions.assertEquals(3, Shard.slowQuorumSize(5));
      }
  
      @Test
      void simpleFastQuorumSizeTest()
      {
          // rf=3
          assertSimpleFastQuorumSize(3, 3, 3);
          assertSimpleFastQuorumSize(2, 3, 2);
          assertInvalidFastPathElectorateSize(3, 1);
  
          // rf=4
          assertSimpleFastQuorumSize(3, 4, 4);
          assertSimpleFastQuorumSize(3, 4, 3);
          assertInvalidFastPathElectorateSize(4, 2);
  
          // rf=5
          assertSimpleFastQuorumSize(4, 5, 5);
          assertSimpleFastQuorumSize(4, 5, 4);
          assertSimpleFastQuorumSize(3, 5, 3);
          assertInvalidFastPathElectorateSize(5, 2);
  
          // rf=6
          assertSimpleFastQuorumSize(5, 6, 6);
          assertSimpleFastQuorumSize(4, 6, 5);
          assertSimpleFastQuorumSize(4, 6, 4);
          assertInvalidFastPathElectorateSize(6, 3);
  
          // rf=7
          assertSimpleFastQuorumSize(6, 7, 7);
          assertSimpleFastQuorumSize(5, 7, 6);
          assertSimpleFastQuorumSize(5, 7, 5);
          assertSimpleFastQuorumSize(4, 7, 4);
          assertInvalidFastPathElectorateSize(7, 3);
  
          // rf=8
          assertSimpleFastQuorumSize(6, 8, 8);
          assertSimpleFastQuorumSize(6, 8, 7);
          assertSimpleFastQuorumSize(5, 8, 6);
          assertInvalidFastPathElectorateSize(8, 4);
  
          // rf=9
          assertSimpleFastQuorumSize(7, 9, 9);
          assertSimpleFastQuorumSize(7, 9, 8);
          assertSimpleFastQuorumSize(6, 9, 7);
          assertSimpleFastQuorumSize(6, 9, 6);
          assertSimpleFastQuorumSize(5, 9, 5);
          assertInvalidFastPathElectorateSize(9, 4);
      }
  
      @Test
      void pendingNodeValidation()
      {
          SortedArrayList<Node.Id> nodes = ids(0, 3);
          Set<Node.Id> fpNodes = new HashSet<>(ids(0, 2));
          // pending nodes are part of electorate
          Shard.create(range(0, 100), nodes, fpNodes, new HashSet<>(ids(3, 3)));
          // pending nodes are not part of electorate
          assertIllegalArgument(() -> Shard.create(range(0, 100), nodes, fpNodes, new HashSet<>(ids(4, 4))),
                                "Expected exception for non-electorate pending nodes");
      }
  }
  