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.cli.command;
  
  import alluxio.Constants;
  import alluxio.cli.Command;
  import alluxio.cli.command.metadatacache.DropAllCommand;
  import alluxio.cli.command.metadatacache.DropCommand;
  import alluxio.cli.command.metadatacache.SizeCommand;
  import alluxio.client.file.FileSystem;
  import alluxio.collections.TwoKeyConcurrentMap;
  import alluxio.conf.AlluxioConfiguration;
  
  import java.util.HashMap;
  import java.util.Map;
  import javax.annotation.concurrent.ThreadSafe;
  
  /**
   * Gets information of or makes changes to the Fuse client metadata cache.
   */
  @ThreadSafe
  public final class MetadataCacheCommand extends AbstractFuseShellCommand {
  
    private static final Map<String, TwoKeyConcurrentMap.TriFunction<FileSystem,
        AlluxioConfiguration, String, ? extends Command>> SUB_COMMANDS = new HashMap<>();
  
    static {
      SUB_COMMANDS.put("dropAll", DropAllCommand::new);
      SUB_COMMANDS.put("drop", DropCommand::new);
      SUB_COMMANDS.put("size", SizeCommand::new);
    }
  
    private final Map<String, Command> mSubCommands = new HashMap<>();
  
    /**
     * @param fs filesystem instance from fuse command
     * @param conf the Alluxio configuration
     */
    public MetadataCacheCommand(FileSystem fs,
        AlluxioConfiguration conf) {
      super(fs, conf, "");
      SUB_COMMANDS.forEach((name, constructor)
          -> mSubCommands.put(name, constructor.apply(fs, conf, getCommandName())));
    }
  
    @Override
    public Map<String, Command> getSubCommands() {
      return mSubCommands;
    }
  
    @Override
    public String getCommandName() {
      return "metadatacache";
    }
  
    @Override
    public String getUsage() {
      // Show usage: metadatacache.(drop|size|dropAll)
      StringBuilder usage = new StringBuilder("ls -l " + Constants.DEAFULT_FUSE_MOUNT
          + Constants.ALLUXIO_CLI_PATH + "." + getCommandName() + ".(");
      for (String cmd : SUB_COMMANDS.keySet()) {
        usage.append(cmd).append("|");
      }
      usage.deleteCharAt(usage.length() - 1).append(')');
      return usage.toString();
    }
  
    @Override
    public String getDescription() {
      return "Metadatacache command is used to drop metadata cache or get cache size.";
    }
  }
  