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;
  
  import alluxio.StorageTierAssoc;
  import alluxio.collections.Pair;
  
  import java.util.List;
  import java.util.Map;
  
  /**
   * Interface for the block store meta in Alluxio.
   */
  public interface BlockStoreMeta {
    /**
     * Note: This method is only available when users initialize
     * the blockStoreMeta with full block meta requirement.
     *
     * @return A mapping from storage tier alias to blocks
     */
    Map<String, List<Long>> getBlockList();
  
    /**
     * Note: This method is only available when users initialize
     * the blockStoreMeta with full block meta requirement.
     *
     * @return A mapping from storage location alias to blocks
     */
    Map<BlockStoreLocation, List<Long>> getBlockListByStorageLocation();
  
    /**
     * @return the capacity in bytes
     */
    long getCapacityBytes();
  
    /**
     * @return a mapping from tier aliases to capacity in bytes
     */
    Map<String, Long> getCapacityBytesOnTiers();
  
    /**
     * @return a mapping from tier directory-path pairs to capacity in bytes
     */
    Map<Pair<String, String>, Long> getCapacityBytesOnDirs();
  
    /**
     * @return a mapping from tier aliases to directory paths in that tier
     */
    Map<String, List<String>> getDirectoryPathsOnTiers();
  
    /**
     * @return a mapping from tier alias to lost storage paths
     */
    Map<String, List<String>> getLostStorage();
  
    /**
     * Note: This is only available when blocks are included.
     *
     * @return the number of blocks
     */
    int getNumberOfBlocks();
  
    /**
     * @return the used capacity in bytes
     */
    long getUsedBytes();
  
    /**
     * @return a mapping from tier aliases to used capacity in bytes
     */
    Map<String, Long> getUsedBytesOnTiers();
  
    /**
     * @return a mapping from tier directory-path pairs to used capacity in bytes
     */
    Map<Pair<String, String>, Long> getUsedBytesOnDirs();
  
    /**
     * @return the storage tier mapping
     */
    StorageTierAssoc getStorageTierAssoc();
  }
  