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.calcite.avatica.server;
  
  import java.util.concurrent.Callable;
  
  /**
   * A callback which the server can invoke to allow implementations to control additional logic
   * about whether or not a client from a specific host should be run.
   * <p>For example, complex logic could be supplied to control whether clientA from host1 is
   * permitted to execute queries. This logic is deferred upon the user to implement.
   */
  public interface DoAsRemoteUserCallback {
  
    /**
     * Invokes the given <code>action</code> as the <code>remoteUserName</code>.
     *
     * @param remoteUserName The remote user making a request to the Avatica server.
     * @param remoteAddress The address the remote user is making the request from.
     * @param action The operation the Avatica server wants to run as <code>remoteUserName</code>.
     * @return The result from the Callable.
     */
    <T> T doAsRemoteUser(String remoteUserName, String remoteAddress, Callable<T> action)
        throws Exception;
  
  }
  
  // End DoAsRemoteUserCallback.java
  