content: /*
   * The Alluxio Open Foundation licenses this work under the Apache License, version 2.0
   * (the "License"). You may not use this work except in compliance with the License, which is
   * available at www.apache.org/licenses/LICENSE-2.0
   *
   * This software is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
   * either express or implied, as more fully set forth in the License.
   *
   * See the NOTICE file distributed with this work for information regarding copyright ownership.
   */
  
  package alluxio.worker.block.evictor;
  
  import alluxio.collections.Pair;
  import alluxio.worker.block.BlockStoreLocation;
  
  import com.google.common.base.MoreObjects;
  import com.google.common.base.Preconditions;
  
  import java.util.List;
  import javax.annotation.concurrent.ThreadSafe;
  
  /**
   * This class provides information about the blocks that need to be moved when evicting.
   */
  @ThreadSafe
  public final class EvictionPlan {
    /** A list of block transfer information, with block id, source and destination location. */
    private final List<BlockTransferInfo> mToMove;
    /** A list of pairs of block id to remove and its location. */
    private final List<Pair<Long, BlockStoreLocation>> mToEvict;
  
    /**
     * Creates a new instance of {@link EvictionPlan}.
     *
     * @param toTransfer a list of block transfer information
     * @param toEvict a list of blocks to be evicted
     */
    public EvictionPlan(List<BlockTransferInfo> toTransfer,
        List<Pair<Long, BlockStoreLocation>> toEvict) {
      mToMove = Preconditions.checkNotNull(toTransfer, "toTransfer");
      mToEvict = Preconditions.checkNotNull(toEvict, "toEvict");
    }
  
    /**
     * @return a list of block transfer information, with block id, source and destination location
     */
    public List<BlockTransferInfo> toMove() {
      return mToMove;
    }
  
    /**
     * @return a list of pairs of block id to remove and its location
     */
    public List<Pair<Long, BlockStoreLocation>> toEvict() {
      return mToEvict;
    }
  
    /**
     * Whether the plan is empty, an empty plan means both toMove and toEvict are empty, also, an
     * empty plan indicates no action (move or evict) needs to be taken to meet the requirement.
     *
     * @return true if empty otherwise false
     */
    public boolean isEmpty() {
      return mToEvict.isEmpty() && mToMove.isEmpty();
    }
  
    @Override
    public String toString() {
      return MoreObjects.toStringHelper(this)
          .add("toMove", mToMove)
          .add("toEvict", mToEvict).toString();
    }
  }
  