content: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you under the Apache License, Version 2.0 (the
   * "License"); you may not use this file except in compliance
   * with the License.  You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.apache.cassandra.auth;
  
  import java.util.EnumSet;
  import java.util.Set;
  
  import com.google.common.collect.ImmutableSet;
  import com.google.common.collect.Sets;
  
  /**
   * An enum encapsulating the set of possible permissions that an authenticated user can have on a resource.
   *
   * IAuthorizer implementations may encode permissions using ordinals, so the Enum order must never change order.
   * Adding new values is ok.
   */
  public enum Permission
  {
      // schema and role management
      // CREATE, ALTER and DROP permissions granted on an appropriate DataResource are required for
      // CREATE KEYSPACE and CREATE TABLE.
      // ALTER KEYSPACE, ALTER TABLE, CREATE INDEX and DROP INDEX require ALTER permission on the
      // relevant DataResource.
      // DROP KEYSPACE and DROP TABLE require DROP permission.
      //
      // In the context of Role management, these permissions may also be granted on a RoleResource.
      // CREATE is only granted on the root-level role resource, and is required to create new roles.
      // ALTER & DROP may be granted on either the root-level role resource, giving permissions on
      // all roles, or on specific role-level resources.
      CREATE,
      ALTER,
      DROP,
  
      // data access
      SELECT, // required for SELECT on a table
      MODIFY, // required for INSERT, UPDATE, DELETE, TRUNCATE on a DataResource.
  
      // permission management
      AUTHORIZE, // required for GRANT and REVOKE of permissions or roles.
  
      DESCRIBE, // required on the root-level RoleResource to list all Roles
  
      // UDF permissions
      EXECUTE,  // required to invoke any user defined function or aggregate
  
      UNMASK, // required to see masked data
  
      SELECT_MASKED; // required for SELECT on a table with restictions on masked columns
  
      public static final Set<Permission> ALL =
              Sets.immutableEnumSet(EnumSet.range(Permission.CREATE, Permission.SELECT_MASKED));
      public static final Set<Permission> NONE = ImmutableSet.of();
  
      /**
       * Set of Permissions which may never be granted on any system keyspace, or table in a system keyspace, to any role.
       * (Only SELECT, DESCRIBE and ALTER may ever be granted).
       */
      public static final Set<Permission> INVALID_FOR_SYSTEM_KEYSPACES =
              Sets.immutableEnumSet(EnumSet.complementOf(EnumSet.of(Permission.SELECT, Permission.DESCRIBE, Permission.ALTER)));
  }
  