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.repair.asymmetric;
  
  import java.util.List;
  import java.util.Map;
  import java.util.Set;
  
  import com.google.common.annotations.VisibleForTesting;
  import com.google.common.collect.ImmutableMap;
  
  import org.apache.cassandra.dht.Range;
  import org.apache.cassandra.dht.Token;
  import org.apache.cassandra.locator.InetAddressAndPort;
  import org.apache.cassandra.repair.TreeResponse;
  import org.apache.cassandra.utils.MerkleTrees;
  
  /**
   * Just holds all differences between the hosts involved in a repair
   */
  public class DifferenceHolder
  {
      private final ImmutableMap<InetAddressAndPort, HostDifferences> differences;
  
      public DifferenceHolder(List<TreeResponse> trees)
      {
          ImmutableMap.Builder<InetAddressAndPort, HostDifferences> diffBuilder = ImmutableMap.builder();
          for (int i = 0; i < trees.size() - 1; ++i)
          {
              TreeResponse r1 = trees.get(i);
              // create the differences between r1 and all other hosts:
              HostDifferences hd = new HostDifferences();
              for (int j = i + 1; j < trees.size(); ++j)
              {
                  TreeResponse r2 = trees.get(j);
                  hd.add(r2.endpoint, MerkleTrees.difference(r1.trees, r2.trees));
              }
              r1.trees.release();
              // and add them to the diff map
              diffBuilder.put(r1.endpoint, hd);
          }
          trees.get(trees.size() - 1).trees.release();
          differences = diffBuilder.build();
      }
  
      @VisibleForTesting
      DifferenceHolder(Map<InetAddressAndPort, HostDifferences> differences)
      {
          ImmutableMap.Builder<InetAddressAndPort, HostDifferences> diffBuilder = ImmutableMap.builder();
          diffBuilder.putAll(differences);
          this.differences = diffBuilder.build();
      }
  
      /**
       * differences only holds one 'side' of the difference - if A and B mismatch, only A will be a key in the map
       */
      public Set<InetAddressAndPort> keyHosts()
      {
          return differences.keySet();
      }
  
      public HostDifferences get(InetAddressAndPort hostWithDifference)
      {
          return differences.get(hostWithDifference);
      }
  
      public String toString()
      {
          return "DifferenceHolder{" +
                 "differences=" + differences +
                 '}';
      }
  
      public boolean hasDifferenceBetween(InetAddressAndPort node1, InetAddressAndPort node2, Range<Token> range)
      {
          HostDifferences diffsNode1 = differences.get(node1);
          if (diffsNode1 != null && diffsNode1.hasDifferencesFor(node2, range))
              return true;
          HostDifferences diffsNode2 = differences.get(node2);
          if (diffsNode2 != null && diffsNode2.hasDifferencesFor(node1, range))
              return true;
          return false;
      }
  }
  