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.meta;
  
  import com.google.common.base.Preconditions;
  
  import java.util.Collection;
  import java.util.HashMap;
  import java.util.Map;
  
  /**
   * This class is an abstract class for allocators and evictors to extend to provide
   * limited access to {@link StorageTier}.
   */
  public abstract class StorageTierView {
  
    /** The {@link StorageTier} this view is derived from. */
    final StorageTier mTier;
    /** A list of {@link StorageDirView} under this StorageTierView. */
    final Map<Integer, StorageDirView> mDirViews = new HashMap<>();
    /** Whether to include reserved space into availability calculations. */
    final boolean mUseReservedSpace;
  
    /**
     * Creates a {@link StorageTierView} using the actual {@link StorageTier}.
     *
     * @param tier which the tierView is constructed from
     */
    public StorageTierView(StorageTier tier) {
      this(tier, false);
    }
  
    /**
     * Creates a {@link StorageTierView} using the actual {@link StorageTier}.
     *
     * @param tier which the tierView is constructed from
     * @param useReservedSpace whether to include reserved space in available bytes
     */
    public StorageTierView(StorageTier tier, boolean useReservedSpace) {
      mTier = Preconditions.checkNotNull(tier, "tier");
      mUseReservedSpace = useReservedSpace;
    }
  
    /**
     * @return a list of directory views in this storage tier view
     */
    public Collection<StorageDirView> getDirViews() {
      return mDirViews.values();
    }
  
    /**
     * Returns a directory view for the given index.
     *
     * @param dirIndex the directory view index
     * @return a directory view
     */
    public StorageDirView getDirView(int dirIndex) {
      return mDirViews.get(dirIndex);
    }
  
    /**
     * @return the storage tier view alias
     */
    public String getTierViewAlias() {
      return mTier.getTierAlias();
    }
  
    /**
     * @return the ordinal value of the storage tier view
     */
    public int getTierViewOrdinal() {
      return mTier.getTierOrdinal();
    }
  }
  