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.locator;
  
  import com.google.common.annotations.VisibleForTesting;
  import com.google.common.base.Preconditions;
  import com.google.common.collect.ImmutableSet;
  import org.apache.cassandra.dht.Range;
  import org.apache.cassandra.dht.Token;
  
  import java.net.UnknownHostException;
  import java.util.Arrays;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.List;
  import java.util.Map;
  import java.util.Objects;
  import java.util.Set;
  import java.util.stream.Collector;
  
  import static com.google.common.collect.Iterables.all;
  import static org.apache.cassandra.locator.ReplicaCollection.Builder.Conflict.*;
  
  /**
   * A ReplicaCollection for Ranges occurring at an endpoint. All Replica will be for the same endpoint,
   * and must be unique Ranges (though overlapping ranges are presently permitted, these should probably not be permitted to occur)
   */
  public class RangesAtEndpoint extends AbstractReplicaCollection<RangesAtEndpoint>
  {
      private static ReplicaMap<Range<Token>> rangeMap(ReplicaList list) { return new ReplicaMap<>(list, Replica::range); }
      private static final ReplicaMap<Range<Token>> EMPTY_MAP = rangeMap(EMPTY_LIST);
  
      private final InetAddressAndPort endpoint;
  
      // volatile not needed, as all of these caching collections have final members,
      // besides (transitively) those that cache objects that themselves have only final members
      private ReplicaMap<Range<Token>> byRange;
      private RangesAtEndpoint onlyFull;
      private RangesAtEndpoint onlyTransient;
  
      private RangesAtEndpoint(InetAddressAndPort endpoint, ReplicaList list, ReplicaMap<Range<Token>> byRange)
      {
          super(list);
          this.endpoint = endpoint;
          this.byRange = byRange;
          assert endpoint != null;
      }
  
      public InetAddressAndPort endpoint()
      {
          return endpoint;
      }
  
      @Override
      public Set<InetAddressAndPort> endpoints()
      {
          return Collections.unmodifiableSet(list.isEmpty()
                  ? Collections.emptySet()
                  : Collections.singleton(endpoint)
          );
      }
  
      /**
       * @return a set of all unique Ranges
       * This method is threadsafe, though it is not synchronised
       */
      public Set<Range<Token>> ranges()
      {
          return byRange().keySet();
      }
  
      /**
       * @return a map of all Ranges, to their owning Replica instance
       * This method is threadsafe, though it is not synchronised
       */
      public Map<Range<Token>, Replica> byRange()
      {
          ReplicaMap<Range<Token>> map = byRange;
          if (map == null)
              byRange = map = rangeMap(list);
          return map;
      }
  
      @Override
      protected RangesAtEndpoint snapshot(ReplicaList newList)
      {
          if (newList.isEmpty()) return empty(endpoint);
          ReplicaMap<Range<Token>> byRange = null;
          if (this.byRange != null && list.isSubList(newList))
              byRange = this.byRange.forSubList(newList);
          return new RangesAtEndpoint(endpoint, newList, byRange);
      }
  
      @Override
      public RangesAtEndpoint snapshot()
      {
          return this;
      }
  
      @Override
      public ReplicaCollection.Builder<RangesAtEndpoint> newBuilder(int initialCapacity)
      {
          return new Builder(endpoint, initialCapacity);
      }
  
      @Override
      public boolean contains(Replica replica)
      {
          return replica != null
                  && Objects.equals(
                          byRange().get(replica.range()),
                          replica);
      }
  
      public RangesAtEndpoint onlyFull()
      {
          RangesAtEndpoint result = onlyFull;
          if (result == null)
              onlyFull = result = filter(Replica::isFull);
          return result;
      }
  
      public RangesAtEndpoint onlyTransient()
      {
          RangesAtEndpoint result = onlyTransient;
          if (result == null)
              onlyTransient = result = filter(Replica::isTransient);
          return result;
      }
  
      public boolean contains(Range<Token> range, boolean isFull)
      {
          Replica replica = byRange().get(range);
          return replica != null && replica.isFull() == isFull;
      }
  
      /**
       * @return if there are no wrap around ranges contained in this RangesAtEndpoint, return self;
       * otherwise, return a RangesAtEndpoint covering the same logical portions of the ring, but with those ranges unwrapped
       */
      public RangesAtEndpoint unwrap()
      {
          int wrapAroundCount = 0;
          for (Replica replica : this)
          {
              if (replica.range().isWrapAround())
                  ++wrapAroundCount;
          }
  
          assert wrapAroundCount <= 1;
          if (wrapAroundCount == 0)
              return snapshot();
  
          RangesAtEndpoint.Builder builder = builder(endpoint, size() + wrapAroundCount);
          for (Replica replica : this)
          {
              if (!replica.range().isWrapAround())
              {
                  builder.add(replica);
                  continue;
              }
              for (Range<Token> range : replica.range().unwrap())
                  builder.add(replica.decorateSubrange(range));
          }
          return builder.build();
      }
  
      public static Collector<Replica, Builder, RangesAtEndpoint> collector(InetAddressAndPort endpoint)
      {
          return collector(ImmutableSet.of(), () -> new Builder(endpoint));
      }
  
      public static class Builder extends RangesAtEndpoint implements ReplicaCollection.Builder<RangesAtEndpoint>
      {
          boolean built;
          public Builder(InetAddressAndPort endpoint) { this(endpoint, 0); }
          public Builder(InetAddressAndPort endpoint, int capacity) { this(endpoint, new ReplicaList(capacity)); }
          private Builder(InetAddressAndPort endpoint, ReplicaList list) { super(endpoint, list, rangeMap(list)); }
  
          public RangesAtEndpoint.Builder add(Replica replica)
          {
              return add(replica, Conflict.DUPLICATE);
          }
  
          public RangesAtEndpoint.Builder add(Replica replica, Conflict ignoreConflict)
          {
              if (built) throw new IllegalStateException();
              Preconditions.checkNotNull(replica);
              if (!Objects.equals(super.endpoint, replica.endpoint()))
                  throw new IllegalArgumentException("Replica " + replica + " has incorrect endpoint (expected " + super.endpoint + ")");
  
              if (!super.byRange.internalPutIfAbsent(replica, list.size()))
              {
                  switch (ignoreConflict)
                  {
                      case DUPLICATE:
                          if (byRange().get(replica.range()).equals(replica))
                              break;
                      case NONE:
                          throw new IllegalArgumentException("Conflicting replica added (expected unique ranges): "
                                  + replica + "; existing: " + byRange().get(replica.range()));
                      case ALL:
                  }
                  return this;
              }
  
              list.add(replica);
              return this;
          }
  
          @Override
          public RangesAtEndpoint snapshot()
          {
              return snapshot(list.subList(0, list.size()));
          }
  
          public RangesAtEndpoint build()
          {
              built = true;
              return new RangesAtEndpoint(super.endpoint, super.list, super.byRange);
          }
      }
  
      public static Builder builder(InetAddressAndPort endpoint)
      {
          return new Builder(endpoint);
      }
      public static Builder builder(InetAddressAndPort endpoint, int capacity)
      {
          return new Builder(endpoint, capacity);
      }
  
      public static RangesAtEndpoint empty(InetAddressAndPort endpoint)
      {
          return new RangesAtEndpoint(endpoint, EMPTY_LIST, EMPTY_MAP);
      }
  
      public static RangesAtEndpoint of(Replica replica)
      {
          ReplicaList one = new ReplicaList(1);
          one.add(replica);
          return new RangesAtEndpoint(replica.endpoint(), one, rangeMap(one));
      }
  
      public static RangesAtEndpoint of(Replica ... replicas)
      {
          return copyOf(Arrays.asList(replicas));
      }
  
      public static RangesAtEndpoint copyOf(List<Replica> replicas)
      {
          if (replicas.isEmpty())
              throw new IllegalArgumentException("Must specify a non-empty collection of replicas");
          return builder(replicas.get(0).endpoint(), replicas.size()).addAll(replicas).build();
      }
  
  
      /**
       * Use of this method to synthesize Replicas is almost always wrong. In repair it turns out the concerns of transient
       * vs non-transient are handled at a higher level, but eventually repair needs to ask streaming to actually move
       * the data and at that point it doesn't have a great handle on what the replicas are and it doesn't really matter.
       *
       * Streaming expects to be given Replicas with each replica indicating what type of data (transient or not transient)
       * should be sent.
       *
       * So in this one instance we can lie to streaming and pretend all the replicas are full and use a dummy address
       * and it doesn't matter because streaming doesn't rely on the address for anything other than debugging and full
       * is a valid value for transientness because streaming is selecting candidate tables from the repair/unrepaired
       * set already.
       * @param ranges
       * @return
       */
      @VisibleForTesting
      public static RangesAtEndpoint toDummyList(Collection<Range<Token>> ranges)
      {
          InetAddressAndPort dummy;
          try
          {
              dummy = InetAddressAndPort.getByNameOverrideDefaults("0.0.0.0", 0);
          }
          catch (UnknownHostException e)
          {
              throw new RuntimeException(e);
          }
  
          //For repair we are less concerned with full vs transient since repair is already dealing with those concerns.
          //Always say full and then if the repair is incremental or not will determine what is streamed.
          return ranges.stream()
                  .map(range -> new Replica(dummy, range, true))
                  .collect(collector(dummy));
      }
  
      public static boolean isDummyList(RangesAtEndpoint ranges)
      {
          return all(ranges, range -> range.endpoint().getHostAddress(true).equals("0.0.0.0:0"));
      }
  
      /**
       * @return concatenate two DISJOINT collections together
       */
      public static RangesAtEndpoint concat(RangesAtEndpoint replicas, RangesAtEndpoint extraReplicas)
      {
          return AbstractReplicaCollection.concat(replicas, extraReplicas, NONE);
      }
  
  }
  