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 alluxio.worker.block.BlockStoreLocation;
  
  import java.util.List;
  import java.util.Optional;
  
  /**
   * Represents a directory in a storage tier. It has a fixed capacity allocated to it on
   * instantiation. It contains the set of blocks currently in the storage directory.
   */
  public interface StorageDir {
    /**
     * Gets the total capacity of this {@link StorageDir} in bytes, which is a constant once this
     * {@link StorageDir} has been initialized.
     *
     * @return the total capacity of this {@link StorageDir} in bytes
     */
    long getCapacityBytes();
  
    /**
     * Gets the total available capacity of this {@link StorageDir} in bytes. This value equals the
     * total capacity of this {@link StorageDir}, minus the used bytes by committed blocks and temp
     * blocks.
     *
     * @return available capacity in bytes
     */
    long getAvailableBytes();
  
    /**
     * Gets the total size of committed blocks in this StorageDir in bytes.
     *
     * @return number of committed bytes
     */
    long getCommittedBytes();
  
    /**
     * @return the path of the directory
     */
    String getDirPath();
  
    /**
     * @return the medium of the storage dir
     */
    String getDirMedium();
  
    /**
     * Returns the {@link StorageTier} containing this {@link StorageDir}.
     *
     * @return {@link StorageTier}
     */
    StorageTier getParentTier();
  
    /**
     * Returns the zero-based index of this dir in its parent {@link StorageTier}.
     *
     * @return index
     */
    int getDirIndex();
  
    /**
     * Returns the list of block ids in this dir.
     *
     * @return a list of block ids
     */
    List<Long> getBlockIds();
  
    /**
     * Returns the list of blocks stored in this dir.
     *
     * @return a list of blocks
     */
    List<BlockMeta> getBlocks();
  
    /**
     * Checks if a block is in this storage dir.
     *
     * @param blockId the block id
     * @return true if the block is in this storage dir, false otherwise
     */
    boolean hasBlockMeta(long blockId);
  
    /**
     * Checks if a temp block is in this storage dir.
     *
     * @param blockId the block id
     * @return true if the block is in this storage dir, false otherwise
     */
    boolean hasTempBlockMeta(long blockId);
  
    /**
     * Gets the {@link BlockMeta} from this storage dir by its block id.
     *
     * @param blockId the block id
     * @return {@link BlockMeta} of the given block or empty
     */
    Optional<BlockMeta> getBlockMeta(long blockId);
  
    /**
     * Gets the {@link TempBlockMeta} from this storage dir by its block id.
     *
     * @param blockId the block id
     * @return {@link TempBlockMeta} of the given block or empty
     */
    Optional<TempBlockMeta> getTempBlockMeta(long blockId);
  
    /**
     * Adds the metadata of a new block into this storage dir.
     *
     * @param blockMeta the metadata of the block
     */
    void addBlockMeta(BlockMeta blockMeta);
  
    /**
     * Adds the metadata of a new block into this storage dir.
     *
     * @param tempBlockMeta the metadata of a temp block to add
     */
    void addTempBlockMeta(TempBlockMeta tempBlockMeta);
  
    /**
     * Removes a block from this storage dir.
     *
     * @param blockMeta the metadata of the block
     */
    void removeBlockMeta(BlockMeta blockMeta);
  
    /**
     * Removes a temp block from this storage dir.
     *
     * @param tempBlockMeta the metadata of the temp block to remove
     */
    void removeTempBlockMeta(TempBlockMeta tempBlockMeta);
  
    /**
     * Changes the size of a temp block.
     *
     * @param tempBlockMeta the metadata of the temp block to resize
     * @param newSize the new size after change in bytes
     */
    void resizeTempBlockMeta(TempBlockMeta tempBlockMeta, long newSize);
  
    /**
     * Cleans up the temp block metadata for each block id passed in.
     *
     * @param sessionId the id of the client associated with the temporary blocks
     * @param tempBlockIds the list of temporary blocks to clean up, non temporary blocks or
     *        nonexistent blocks will be ignored
     */
    void cleanupSessionTempBlocks(long sessionId, List<Long> tempBlockIds);
  
    /**
     * Gets the temporary blocks associated with a session in this {@link StorageDir}, an empty list
     * is returned if the session has no temporary blocks in this {@link StorageDir}.
     *
     * @param sessionId the id of the session
     * @return A list of temporary blocks the session is associated with in this {@link StorageDir}
     */
    List<TempBlockMeta> getSessionTempBlocks(long sessionId);
  
    /**
     * @return the block store location of this directory
     */
    BlockStoreLocation toBlockStoreLocation();
  
    /**
     * @return amount of reserved bytes for this dir
     */
    long getReservedBytes();
  }
  