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.ArrayList;
  import java.util.Collection;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Set;
  
  import com.google.common.annotations.VisibleForTesting;
  
  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.PlacementDeltas;
  import org.apache.cassandra.tcm.ownership.PlacementProvider;
  import org.apache.cassandra.tcm.ownership.PlacementTransitionPlan;
  import org.apache.cassandra.tcm.sequences.LockedRanges;
  import org.apache.cassandra.tcm.sequences.Move;
  import org.apache.cassandra.tcm.serialization.AsymmetricMetadataSerializer;
  import org.apache.cassandra.tcm.serialization.Version;
  
  import static org.apache.cassandra.exceptions.ExceptionCode.INVALID;
  
  public class PrepareMove implements Transformation
  {
      public static final Serializer<PrepareMove> serializer = new Serializer<PrepareMove>();
  
      protected final NodeId nodeId;
      protected final Set<Token> tokens;
      protected final PlacementProvider placementProvider;
      protected final boolean streamData;
  
      public PrepareMove(NodeId nodeId,
                         Set<Token> tokens,
                         PlacementProvider placementProvider,
                         boolean streamData)
      {
          this.nodeId = nodeId;
          this.tokens = tokens;
          this.placementProvider = placementProvider;
          this.streamData = streamData;
      }
  
      @VisibleForTesting
      public NodeId nodeId()
      {
          return nodeId;
      }
  
      @Override
      public String toString()
      {
          return "PrepareMove{" +
                 "nodeId=" + nodeId +
                 ", tokens=" + tokens +
                 ", streamData=" + streamData +
                 '}';
      }
  
      @Override
      public Kind kind()
      {
          return Kind.PREPARE_MOVE;
      }
  
      @Override
      public Result execute(ClusterMetadata prev)
      {
          if (prev.directory.peerState(nodeId) != NodeState.JOINED)
              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.planForMove(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());
          StartMove startMove = new StartMove(nodeId, transitionPlan.addToWrites(), lockKey);
          MidMove midMove = new MidMove(nodeId, transitionPlan.moveReads(), lockKey);
          FinishMove finishMove = new FinishMove(nodeId, tokens, transitionPlan.removeFromWrites(), lockKey);
          transitionPlan.assertPreExistingWriteReplica(prev.placements);
  
          Move sequence = Move.newSequence(prev.nextEpoch(),
                                           lockKey,
                                           tokens,
                                           transitionPlan.toSplit,
                                           startMove,
                                           midMove,
                                           finishMove,
                                           false);
  
          return Transformation.success(prev.transformer()
                                            .withNodeState(nodeId, NodeState.MOVING)
                                            .with(prev.lockedRanges.lock(lockKey, rangesToLock))
                                            .with(transitionPlan.toSplit.apply(prev.nextEpoch(), prev.placements))
                                            .with(prev.inProgressSequences.with(nodeId, sequence)),
                                        rangesToLock);
      }
  
      public static class Serializer<T extends PrepareMove> 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.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 streamData = in.readBoolean();
              return construct(id, tokens, ClusterMetadataService.instance().placementProvider(), 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;
              return size;
          }
  
          public T construct(NodeId nodeId,
                             Set<Token> tokens,
                             PlacementProvider placementProvider,
                             boolean streamData)
          {
              return (T) new PrepareMove(nodeId, tokens, placementProvider, streamData);
          }
  
      }
  
      public static class StartMove extends ApplyPlacementDeltas
      {
          public static final Serializer serializer = new Serializer();
  
          @VisibleForTesting
          public StartMove(NodeId nodeId, PlacementDeltas delta, LockedRanges.Key lockKey)
          {
              super(nodeId, delta, lockKey, false);
          }
  
          @Override
          public Kind kind()
          {
              return Kind.START_MOVE;
          }
  
          @Override
          public ClusterMetadata.Transformer transform(ClusterMetadata prev, ClusterMetadata.Transformer transformer)
          {
              return transformer.with(prev.inProgressSequences.with(nodeId, (plan) -> plan.advance(prev.nextEpoch())));
          }
  
          public static final class Serializer extends SerializerBase<PrepareMove.StartMove>
          {
              StartMove construct(NodeId nodeId, PlacementDeltas delta, LockedRanges.Key lockKey)
              {
                  return new PrepareMove.StartMove(nodeId, delta, lockKey);
              }
          }
      }
  
      public static class MidMove extends ApplyPlacementDeltas
      {
          public static final Serializer serializer = new Serializer();
  
          @VisibleForTesting
          public MidMove(NodeId nodeId, PlacementDeltas delta, LockedRanges.Key lockKey)
          {
              super(nodeId, delta, lockKey, false);
          }
  
          @Override
          public Kind kind()
          {
              return Kind.MID_MOVE;
          }
  
          @Override
          public ClusterMetadata.Transformer transform(ClusterMetadata prev, ClusterMetadata.Transformer transformer)
          {
              return transformer.with(prev.inProgressSequences.with(nodeId, (plan) -> plan.advance(prev.nextEpoch())));
          }
  
          public static final class Serializer extends SerializerBase<PrepareMove.MidMove>
          {
              MidMove construct(NodeId nodeId, PlacementDeltas delta, LockedRanges.Key lockKey)
              {
                  return new PrepareMove.MidMove(nodeId, delta, lockKey);
              }
          }
      }
  
      public static class FinishMove extends ApplyPlacementDeltas
      {
          public static final Serializer serializer = new Serializer();
  
          public final Collection<Token> newTokens;
  
          @VisibleForTesting
          public FinishMove(NodeId nodeId, Collection<Token> newTokens, PlacementDeltas delta, LockedRanges.Key lockKey)
          {
              super(nodeId, delta, lockKey, true);
              this.newTokens = newTokens;
          }
  
          @Override
          public Kind kind()
          {
              return Kind.FINISH_MOVE;
          }
  
          @Override
          public ClusterMetadata.Transformer transform(ClusterMetadata prev, ClusterMetadata.Transformer transformer)
          {
              return transformer.moveTokens(nodeId, newTokens)
                                .join(nodeId)
                                .with(prev.inProgressSequences.without(nodeId));
          }
  
          public static final class Serializer extends SerializerBase<PrepareMove.FinishMove>
          {
              @Override
              public void serialize(Transformation t, DataOutputPlus out, Version version) throws IOException
              {
                  super.serialize(t, out, version);
                  Collection<Token> tokens = ((FinishMove)t).newTokens;
                  out.writeUnsignedVInt32(tokens.size());
                  for (Token token : tokens)
                      Token.metadataSerializer.serialize(token, out, version);
              }
  
              public FinishMove 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();
                  List<Token> tokens = new ArrayList<>();
                  IPartitioner partitioner = ClusterMetadata.current().partitioner;
                  for (int i = 0; i < numTokens; i++)
                      tokens.add(Token.metadataSerializer.deserialize(in, partitioner, version));
  
                  return new FinishMove(nodeId, tokens, delta, lockKey);
              }
  
              public long serializedSize(Transformation t, Version version)
              {
                  long size = super.serializedSize(t, version);
                  Collection<Token> tokens = ((FinishMove)t).newTokens;
                  size += TypeSizes.sizeofUnsignedVInt(tokens.size());
                  for (Token token : tokens)
                      size += Token.metadataSerializer.serializedSize(token, version);
                  return size;
              }
  
              FinishMove construct(NodeId nodeId, PlacementDeltas delta, LockedRanges.Key lockKey)
              {
                  throw new IllegalStateException();
              }
          }
      }
  }
  