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.tcm.transformations;
  
  import java.io.IOException;
  import java.util.HashSet;
  import java.util.Set;
  
  import com.google.common.collect.ImmutableSet;
  
  import org.apache.cassandra.db.TypeSizes;
  import org.apache.cassandra.dht.IPartitioner;
  import org.apache.cassandra.dht.Token;
  import org.apache.cassandra.io.util.DataInputPlus;
  import org.apache.cassandra.io.util.DataOutputPlus;
  import org.apache.cassandra.tcm.ClusterMetadata;
  import org.apache.cassandra.tcm.ClusterMetadataService;
  import org.apache.cassandra.tcm.Transformation;
  import org.apache.cassandra.tcm.membership.NodeId;
  import org.apache.cassandra.tcm.membership.NodeState;
  import org.apache.cassandra.tcm.ownership.DataPlacements;
  import org.apache.cassandra.tcm.ownership.PlacementDeltas;
  import org.apache.cassandra.tcm.ownership.PlacementProvider;
  import org.apache.cassandra.tcm.ownership.PlacementTransitionPlan;
  import org.apache.cassandra.tcm.sequences.BootstrapAndJoin;
  import org.apache.cassandra.tcm.sequences.LockedRanges;
  import org.apache.cassandra.tcm.serialization.AsymmetricMetadataSerializer;
  import org.apache.cassandra.tcm.serialization.Version;
  
  import static org.apache.cassandra.exceptions.ExceptionCode.INVALID;
  
  /**
   * Create a plan for adding a new node and bootstrapping it, then start to execute that plan.
   * Creating the plan involves adding the joining node's tokens to the current tokenmap and generating the set of
   * required operations to be applied to existing data placements.
   * Specifically, this involves splitting the ranges containing the new node's tokens and adding the new node as a
   * write replica for those ranges. After the new node has completed streaming for bootstrap, it is made a read
   * replica for those ranges.
   *
   * For example, if we start with a (subset of a) ring where A has token 100, B has token 200 and C has token 300
   * with RF=2 then both the read and write placements will contain:
   *
   *  (0, 100]    : {A,B}
   *  (100, 200]  : {B,C}
   *
   * If we then begin bootstrap X with token 150, the first step is to range split the existing ranges in line without
   * changing any ownership. At this point, both the read and write placements will contain:
   *
   *  (0, 100]    : {A,B}
   *  (100, 150]  : {B,C}
   *  (150, 200]  : {B,C}
   *
   * Next, the new node is added to the write groups for the ranges it is acquiring. After this step, the read placement
   * is unchanged, while the write placement will contain:
   *
   *  (0, 100]    : {A,B,X}
   *  (100, 150]  : {B,C,X}
   *  (150, 200]  : {B,C}
   *
   * Once X completes bootstrapping, it is added to the corresponding read groups, replacing nodes which are no longer
   * replicas for those ranges. Now both the read and write placements will contain:
   *
   *  (0, 100]    : {A,X}
   *  (100, 150]  : {X,B}
   *  (150, 200]  : {B,C}
   *
   * Currently, we do not automatically clean up unowned ranges after bootstrap, so C will still hold data for
   * (100, 150] on disk even though it is no longer a replica for that range.
   */
  public class PrepareJoin implements Transformation
  {
      public static final Serializer<PrepareJoin> serializer = new Serializer<PrepareJoin>()
      {
          public PrepareJoin construct(NodeId nodeId, Set<Token> tokens, PlacementProvider placementProvider, boolean joinTokenRing, boolean streamData)
          {
              return new PrepareJoin(nodeId, tokens, placementProvider, joinTokenRing, streamData);
          }
      };
  
      protected final NodeId nodeId;
      protected final Set<Token> tokens;
      protected final PlacementProvider placementProvider;
      protected final boolean joinTokenRing;
      protected final boolean streamData;
  
      public PrepareJoin(NodeId nodeId,
                         Set<Token> tokens,
                         PlacementProvider placementProvider,
                         boolean joinTokenRing,
                         boolean streamData)
      {
          this.nodeId = nodeId;
          this.tokens = tokens;
          this.placementProvider = placementProvider;
          this.joinTokenRing = joinTokenRing;
          this.streamData = streamData;
      }
  
      @Override
      public Kind kind()
      {
          return Kind.PREPARE_JOIN;
      }
  
      public NodeId nodeId()
      {
          return nodeId;
      }
  
      private static final Set<NodeState> ALLOWED_STATES = ImmutableSet.of(NodeState.REGISTERED, NodeState.LEFT);
  
      @Override
      public Result execute(ClusterMetadata prev)
      {
          if (!ALLOWED_STATES.contains(prev.directory.peerState(nodeId)))
              return new Rejected(INVALID, String.format("Rejecting this plan as the node %s is in state %s",
                                                         nodeId, prev.directory.peerState(nodeId)));
  
          PlacementTransitionPlan transitionPlan = placementProvider.planForJoin(prev, nodeId, tokens, prev.schema.getKeyspaces());
  
          LockedRanges.AffectedRanges rangesToLock = transitionPlan.affectedRanges();
          LockedRanges.Key alreadyLockedBy = prev.lockedRanges.intersects(rangesToLock);
          if (!alreadyLockedBy.equals(LockedRanges.NOT_LOCKED))
          {
              return new Rejected(INVALID, String.format("Rejecting this plan as it interacts with a range locked by %s (locked: %s, new: %s)",
                                                         alreadyLockedBy, prev.lockedRanges, rangesToLock));
          }
  
          LockedRanges.Key lockKey = LockedRanges.keyFor(prev.nextEpoch());
          StartJoin startJoin = new StartJoin(nodeId, transitionPlan.addToWrites(), lockKey);
          MidJoin midJoin = new MidJoin(nodeId, transitionPlan.moveReads(), lockKey);
          FinishJoin finishJoin = new FinishJoin(nodeId, tokens, transitionPlan.removeFromWrites(), lockKey);
  
          BootstrapAndJoin plan = BootstrapAndJoin.newSequence(prev.nextEpoch(),
                                                               lockKey,
                                                               transitionPlan.toSplit,
                                                               startJoin, midJoin, finishJoin,
                                                               joinTokenRing, streamData);
          if (!prev.tokenMap.isEmpty())
              assertPreExistingWriteReplica(prev.placements, transitionPlan);
  
          LockedRanges newLockedRanges = prev.lockedRanges.lock(lockKey, rangesToLock);
          DataPlacements startingPlacements = transitionPlan.toSplit.apply(prev.nextEpoch(), prev.placements);
          ClusterMetadata.Transformer proposed = prev.transformer()
                                                     .with(newLockedRanges)
                                                     .with(startingPlacements)
                                                     .with(prev.inProgressSequences.with(nodeId, plan));
  
          return Transformation.success(proposed, rangesToLock);
      }
  
      void assertPreExistingWriteReplica(DataPlacements placements, PlacementTransitionPlan transitionPlan)
      {
          transitionPlan.assertPreExistingWriteReplica(placements);
      }
  
      public static abstract class Serializer<T extends PrepareJoin> implements AsymmetricMetadataSerializer<Transformation, T>
      {
          public void serialize(Transformation t, DataOutputPlus out, Version version) throws IOException
          {
              T transformation = (T) t;
              NodeId.serializer.serialize(transformation.nodeId, out, version);
              out.writeInt(transformation.tokens.size());
              for(Token token : transformation.tokens)
                  Token.metadataSerializer.serialize(token, out, version);
              out.writeBoolean(transformation.joinTokenRing);
              out.writeBoolean(transformation.streamData);
          }
  
          public T deserialize(DataInputPlus in, Version version) throws IOException
          {
              NodeId id = NodeId.serializer.deserialize(in, version);
              int numTokens = in.readInt();
              Set<Token> tokens = new HashSet<>(numTokens);
              IPartitioner partitioner = ClusterMetadata.current().partitioner;
              for (int i = 0; i < numTokens; i++)
                  tokens.add(Token.metadataSerializer.deserialize(in, partitioner, version));
              boolean joinTokenRing = in.readBoolean();
              boolean streamData = in.readBoolean();
              return construct(id, tokens, ClusterMetadataService.instance().placementProvider(), joinTokenRing, streamData);
          }
  
          public long serializedSize(Transformation t, Version version)
          {
              T transformation = (T) t;
              long size = NodeId.serializer.serializedSize(transformation.nodeId, version);
              size += TypeSizes.INT_SIZE;
              for (Token token : transformation.tokens)
                  size += Token.metadataSerializer.serializedSize(token, version);
              size += TypeSizes.BOOL_SIZE * 2;
              return size;
          }
  
          public abstract T construct(NodeId nodeId,
                                      Set<Token> tokens,
                                      PlacementProvider placementProvider,
                                      boolean joinTokenRing,
                                      boolean streamData);
  
      }
  
      public String toString()
      {
          return "PrepareJoin{" +
                 "nodeId=" + nodeId +
                 ", tokens=" + tokens +
                 ", joinTokenRing=" + joinTokenRing +
                 ", streamData=" + streamData +
                 '}';
      }
  
      public static class StartJoin extends ApplyPlacementDeltas
      {
          public static final Serializer serializer = new Serializer();
  
          public StartJoin(NodeId nodeId, PlacementDeltas delta, LockedRanges.Key lockKey)
          {
              super(nodeId, delta, lockKey, false);
          }
  
          @Override
          public Kind kind()
          {
              return Kind.START_JOIN;
          }
  
          @Override
          public ClusterMetadata.Transformer transform(ClusterMetadata prev, ClusterMetadata.Transformer transformer)
          {
              return transformer.withNodeState(nodeId, NodeState.BOOTSTRAPPING)
                                .with(prev.inProgressSequences.with(nodeId, (BootstrapAndJoin plan) -> plan.advance(prev.nextEpoch())));
          }
  
          public static final class Serializer extends SerializerBase<StartJoin>
          {
              StartJoin construct(NodeId nodeId, PlacementDeltas delta, LockedRanges.Key lockKey)
              {
                  return new StartJoin(nodeId, delta, lockKey);
              }
          }
      }
  
      public static class MidJoin extends ApplyPlacementDeltas
      {
          public static final Serializer serializer = new Serializer();
  
          public MidJoin(NodeId nodeId, PlacementDeltas delta, LockedRanges.Key lockKey)
          {
              super(nodeId, delta, lockKey, false);
          }
  
          @Override
          public Kind kind()
          {
              return Kind.MID_JOIN;
          }
  
          @Override
          public ClusterMetadata.Transformer transform(ClusterMetadata prev, ClusterMetadata.Transformer transformer)
          {
              return transformer.with(prev.inProgressSequences.with(nodeId, (BootstrapAndJoin plan) -> plan.advance(prev.nextEpoch())));
          }
  
          public static final class Serializer extends SerializerBase<MidJoin>
          {
              MidJoin construct(NodeId nodeId, PlacementDeltas delta, LockedRanges.Key lockKey)
              {
                  return new MidJoin(nodeId, delta, lockKey);
              }
          }
      }
  
      public static class FinishJoin extends ApplyPlacementDeltas
      {
          public static final Serializer serializer = new Serializer();
          public final Set<Token> tokens;
  
          public FinishJoin(NodeId nodeId, Set<Token> tokens, PlacementDeltas delta, LockedRanges.Key unlockKey)
          {
              super(nodeId, delta, unlockKey, true);
              this.tokens = tokens;
          }
  
          @Override
          public Kind kind()
          {
              return Kind.FINISH_JOIN;
          }
  
          @Override
          public ClusterMetadata.Transformer transform(ClusterMetadata prev, ClusterMetadata.Transformer transformer)
          {
              return transformer.join(nodeId)
                                .proposeToken(nodeId, tokens)
                                .addToRackAndDC(nodeId)
                                .with(prev.inProgressSequences.without(nodeId));
          }
  
          public static final class Serializer extends SerializerBase<FinishJoin>
          {
              @Override
              public void serialize(Transformation t, DataOutputPlus out, Version version) throws IOException
              {
                  super.serialize(t, out, version);
                  Set<Token> tokens = ((FinishJoin)t).tokens;
                  out.writeUnsignedVInt32(tokens.size());
                  for (Token token : tokens)
                      Token.metadataSerializer.serialize(token, out, version);
              }
  
              @Override
              public FinishJoin deserialize(DataInputPlus in, Version version) throws IOException
              {
                  NodeId nodeId = NodeId.serializer.deserialize(in, version);
                  PlacementDeltas delta = PlacementDeltas.serializer.deserialize(in, version);
                  LockedRanges.Key lockKey = LockedRanges.Key.serializer.deserialize(in, version);
                  int numTokens = in.readUnsignedVInt32();
                  Set<Token> tokens = new HashSet<>();
                  IPartitioner partitioner = ClusterMetadata.current().partitioner;
                  for (int i = 0; i < numTokens; i++)
                      tokens.add(Token.metadataSerializer.deserialize(in, partitioner, version));
                  return new FinishJoin(nodeId, tokens, delta, lockKey);
              }
  
              @Override
              public long serializedSize(Transformation t, Version version)
              {
                  long size = super.serializedSize(t, version);
                  Set<Token> tokens = ((FinishJoin)t).tokens;
                  size += TypeSizes.sizeofUnsignedVInt(tokens.size());
                  for (Token token : tokens)
                      size += Token.metadataSerializer.serializedSize(token, version);
                  return size;
              }
  
              FinishJoin construct(NodeId nodeId, PlacementDeltas delta, LockedRanges.Key lockKey)
              {
                  throw new IllegalStateException();
              }
          }
      }
  }