/*
 * 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.drill.exec.alias;

import java.util.Iterator;
import java.util.Map;

/**
 * Registry for public and user-owned aliases.
 */
public interface AliasRegistry extends AutoCloseable {
  /**
   * Returns aliases table for specified {@code userName}.
   *
   * @param userName name of the user whose aliases table should be obtained
   * @return aliases table for specified {@code userName}
   */
  Aliases getUserAliases(String userName);

  /**
   * Returns public aliases table.
   */
  Aliases getPublicAliases();

  /**
   * Creates if required aliases table for specified {@code userName}.
   *
   * @param userName name of the user whose aliases table should be created
   */
  void createUserAliases(String userName);

  /**
   * Creates if required public aliases table.
   */
  void createPublicAliases();

  /**
   * Deletes aliases table for specified {@code userName}.
   *
   * @param userName name of the user whose aliases table should be removed
   */
  void deleteUserAliases(String userName);

  /**
   * Deletes public aliases table.
   */
  void deletePublicAliases();

  /**
   * Returns iterator for aliases table entries.
   */
  Iterator<Map.Entry<String, Aliases>> getAllAliases();
}
