# ServerHelper.java

    /*
    ** Module   : ServerHelper.java
    ** Abstract : defines common APIs for servers connected to an appserver or web service.
    **
    ** Copyright (c) 2013-2019, Golden Code Development Corporation.
    **
    ** -#- -I- --Date-- -------------------------------Description------------------------------------
    ** 001 CA  20131220 Created initial version.
    ** 002 CA  20150416 Added isConnected.
    ** 003 CA  20160404 Enhanced the appserver invocations, to allow implicit or explicit termination
    **                  of requests being executing on a certain connection.
    ** 004 CA  20190118 disconnect() must be aware if the FWD session is gone.
    ** 005 CA  20190326 Added back disconnect() without arguments, to allow backwards compatibility.
    ** 006 CA  20190628 Added invoke() API which uses a InvokeConfig instance.
    */
    /*
    ** This program is free software: you can redistribute it and/or modify
    ** it under the terms of the GNU Affero General Public License as
    ** published by the Free Software Foundation, either version 3 of the
    ** License, or (at your option) any later version.
    **
    ** This program is distributed in the hope that it will be useful,
    ** but WITHOUT ANY WARRANTY; without even the implied warranty of
    ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    ** GNU Affero General Public License for more details.
    **
    ** You may find a copy of the GNU Affero GPL version 3 at the following
    ** location: https://www.gnu.org/licenses/agpl-3.0.en.html
    **
    ** Additional terms under GNU Affero GPL version 3 section 7:
    **
    **   Under Section 7 of the GNU Affero GPL version 3, the following additional
    **   terms apply to the works covered under the License.  These additional terms
    **   are non-permissive additional terms allowed under Section 7 of the GNU
    **   Affero GPL version 3 and may not be removed by you.
    **
    **   0. Attribution Requirement.
    **
    **     You must preserve all legal notices or author attributions in the covered
    **     work or Appropriate Legal Notices displayed by works containing the covered
    **     work.  You may not remove from the covered work any author or developer
    **     credit already included within the covered work.
    **
    **   1. No License To Use Trademarks.
    **
    **     This license does not grant any license or rights to use the trademarks
    **     Golden Code, FWD, any Golden Code or FWD logo, or any other trademarks
    **     of Golden Code Development Corporation. You are not authorized to use the
    **     name Golden Code, FWD, or the names of any author or contributor, for
    **     publicity purposes without written authorization.
    **
    **   2. No Misrepresentation of Affiliation.
    **
    **     You may not represent yourself as Golden Code Development Corporation or FWD.
    **
    **     You may not represent yourself for publicity purposes as associated with
    **     Golden Code Development Corporation, FWD, or any author or contributor to
    **     the covered work, without written authorization.
    **
    **   3. No Misrepresentation of Source or Origin.
    **
    **     You may not represent the covered work as solely your work.  All modified
    **     versions of the covered work must be marked in a reasonable way to make it
    **     clear that the modified work is not originating from Golden Code Development
    **     Corporation or FWD.  All modified versions must contain the notices of
    **     attribution required in this license.
    */

    package com.goldencode.p2j.util;

    /**
     * Defines common APIs used by a server connected to either an appserver or a web service.
     */
    public abstract class ServerHelper
    {
       /** The {@link ServerImpl} instance associated with this helper. */
       protected ServerImpl server;

       /**
        * Get the name of this server.
        *
        * @return   See above.
        */
       public abstract String getServerName();

       /**
        * Get the sub-type of this server.
        *
        * @return   See above.
        */
       public abstract String getSubType();

       /**
        * Get the connection ID.
        *
        * @return   See above.
        */
       public abstract String getConnectionID();

       /**
        * Check if this is a web service.
        *
        * @return   <code>true</code> if we are connected to a web service.
        */
       public abstract boolean isWebService();

       /**
        * Check if this is a session-free connection.
        *
        * @return   <code>true</code> if this is a session-free connection.
        */
       public abstract boolean isSessionFree();

       /**
        * Disconnect this server.
        *
        * @param    disconnecting
        *           Flag indicating if the FWD client session is being terminated.
        */
       public abstract void disconnect(boolean disconnecting);

       /**
        * Check if the connection is still established.
        *
        * @return   <code>true</code> if the server is currently connected.
        */
       public abstract boolean isConnected();

       /**
        * Send a STOP condition to the specified async request.
        *
        * @param    requestId
        *           The request where to send a STOP condition.
        */
       public abstract void sendStop(int requestId);

       /**
        * Send a STOP condition to the request(s) currently being executed on this connection.
        */
       public abstract void sendStop();

       /**
        * Invoke a remote external procedure, internal procedure, user-defined function or web service
        * operation. The validation for the name and arguments will be specific to the established
        * server connection subtype.
        *
        * @param    timeout
        *           The maximum allowed time for this invocation to complete.  In milliseconds.
        *           Use <code>0</code> to disable the timeout.
        * @param    name
        *           The legacy 4GL name for the procedure/function.
        * @param    h
        *           The persistent procedure in which to invoke the internal procedure, function or
        *           operation.
        * @param    function
        *           <code>true</code> if this is a function call.
        * @param    dynamicFunction
        *           <code>true</code> if this is a DYNAMIC-FUNCTION call.
        * @param    superCall
        *           <code>true</code> if this is a RUN SUPER or SUPER() call.
        * @param    transactionDistinct
        *           Flag indicating if the TRANSACTION DISTINCT clause is in effect.
        * @param    modes
        *           A string representation of the modes of each parameter. The modes may be mandatory
        *           for a specific implementation.
        * @param    args
        *           The procedure's arguments.
        *
        * @return   The result of this procedure/function invocation or <code>null</code> if the
        *           invocation could not be performed.
        */
       abstract BaseDataType invoke(long             timeout,
                                    AsyncRequestImpl asyncReq,
                                    character        name,
                                    handle           h,
                                    boolean          function,
                                    boolean          dynamicFunction,
                                    boolean          superCall,
                                    boolean          transactionDistinct,
                                    String           modes,
                                    Object...        args);

       /**
        * Invoke a remote external procedure, internal procedure, user-defined function or web service
        * operation. The validation for the name and arguments will be specific to the established
        * server connection subtype.
        *
        * @param    timeout
        *           The maximum allowed time for this invocation to complete.  In milliseconds.
        *           Use <code>0</code> to disable the timeout.
        * @param    asyncReq
        *           When not-null, an {@link AsyncRequestImpl} instance for the associated async
        *           request.
        * @param    cfg
        *           The invoke configuration.
        *
        * @return   The result of this procedure/function invocation or <code>null</code> if the
        *           invocation could not be performed.
        */
       abstract BaseDataType invoke(long timeout, AsyncRequestImpl asyncReq, InvokeConfig cfg);

       /**
        * Disconnect this server - this assumes the FWD connection is being terminated.
        */
       public void disconnect()
       {
          disconnect(true);
       }

       /**
        * Set the {@link ServerImpl} instance associated with this helper.
        *
        * @param    server
        *           The {@link ServerImpl} instance.
        */
       void setServer(ServerImpl server)
       {
          this.server = server;
       }

       /**
        * Get the {@link #server} instance associated with this helper.
        *
        * @return   See above.
        */
       ServerImpl getServer()
       {
          return server;
       }
    }