content: /*
   * Copyright 1999-2012 Alibaba Group.
   *  
   * Licensed 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 com.alibaba.cobar.net.handler;
  
  import java.util.Set;
  
  /**
   * 权限提供者
   * 
   * @author xianmao.hexm
   */
  public interface FrontendPrivileges {
  
      /**
       * 检查schema是否存在
       */
      boolean schemaExists(String schema);
  
      /**
       * 检查用户是否存在，并且可以使用host实行隔离策略。
       */
      boolean userExists(String user, String host);
  
      /**
       * 提供用户的服务器端密码
       */
      String getPassword(String user);
  
      /**
       * 提供有效的用户schema集合
       */
      Set<String> getUserSchemas(String user);
  
  }
  