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.maelstrom;
  
  import java.util.ArrayList;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  import java.util.Set;
  
  import accord.primitives.Range;
  import accord.local.Node.Id;
  import accord.maelstrom.Datum.Kind;
  import accord.topology.Shard;
  import accord.topology.Topology;
  import accord.utils.WrapAroundList;
  import accord.utils.WrapAroundSet;
  
  import static accord.utils.SortedArrays.SortedArrayList.copyUnsorted;
  import static accord.utils.Utils.toArray;
  
  public class TopologyFactory
  {
      final int shards;
      final int rf;
      final Kind[] kinds;
      final Range[][] ranges;
  
      public TopologyFactory(int shards, int rf)
      {
          this.shards = shards;
          this.rf = rf;
          this.kinds = Datum.COMPARE_BY_HASH ? new Kind[] { Kind.HASH } : new Kind[] { Kind.STRING, Kind.LONG, Kind.DOUBLE };
          this.ranges = new MaelstromKey.Range[kinds.length][shards];
          for (int i = 0 ; i < kinds.length ; ++i)
          {
              Kind kind = kinds[i];
              MaelstromKey.Routing[] starts = kind.split(shards);
              MaelstromKey.Routing[] ends = new MaelstromKey.Routing[shards];
              System.arraycopy(starts, 1, ends, 0, shards - 1);
              ends[shards - 1] = new MaelstromKey.Routing(kind, null);
              this.ranges[i] = new MaelstromKey.Range[shards];
              for (int j=0; j<shards; j++)
                  ranges[i][j] = new MaelstromKey.Range(starts[j], ends[j]);
          }
      }
  
  
      public Topology toTopology(Id[] cluster)
      {
          final Map<Id, Integer> lookup = new HashMap<>();
          for (int i = 0 ; i < cluster.length ; ++i)
              lookup.put(cluster[i], i);
  
          List<WrapAroundList<Id>> electorates = new ArrayList<>();
          List<Set<Id>> fastPathElectorates = new ArrayList<>();
  
          for (int i = 0 ; i < cluster.length + rf - 1 ; ++i)
          {
              WrapAroundList<Id> electorate = new WrapAroundList<>(cluster, i % cluster.length, (i + rf) % cluster.length);
              Set<Id> fastPathElectorate = new WrapAroundSet<>(lookup, electorate);
              electorates.add(electorate);
              fastPathElectorates.add(fastPathElectorate);
          }
  
          final List<Shard> shards = new ArrayList<>();
          for (int j = 0 ; j < kinds.length ; ++j)
          {
              for (int i = 0 ; i < this.shards ; ++i)
                  shards.add(Shard.create(ranges[j][i], copyUnsorted(electorates.get(i % electorates.size()), Id[]::new), fastPathElectorates.get(i % fastPathElectorates.size())));
          }
          return new Topology(1, Topology.NO_IDS, Topology.NO_IDS, toArray(shards, Shard[]::new));
      }
  }
  