ServerResourceManager.java

/*
** Module   : ServerResourceManager.java
** Abstract : Management of server OS resources.
**
** Copyright (c) 2022-2024, Golden Code Development Corporation.
**
** -#- -I- --Date-- ---------------------------------------Description----------------------------------------
** 001 CA  20220515 Created initial version.
**     RFB 20220524 Fixed minor javadoc error.
**      CA 20220918 Allow legacy client sockets to be ran on FWD server instead of FWD client.
** 002 HC  20230427 Implemented server-side file-system resource. File operations performed on
**                  client can be optionally performed directly on server without the expensive
**                  remote call.
** 003 HC  20230517 Implemented server-side web service calling.
** 004 GBB 20240826 Saving instantiated resources to an instance fields of type map 
**                  (the manager is context local). Adding initializeEnvironments.
** 005 GBB 20240912 Adding support for types mail, launcher and streams. 
**                  Renaming ServerSideResourceManager to ServerResourceManager.
*/

/*
** 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.
** 
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**     work or Appropriate Legal Notices displayed by works containing the covered
**     work.  You may not remove from the covered work any author or developer
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**     This license does not grant any license or rights to use the trademarks
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**     attribution required in this license.
*/

package com.goldencode.p2j.util.osresource;

import com.goldencode.p2j.library.*;
import com.goldencode.p2j.net.*;
import com.goldencode.p2j.ui.*;
import com.goldencode.p2j.ui.chui.*;
import com.goldencode.p2j.ui.client.*;
import com.goldencode.p2j.util.*;
import com.goldencode.util.*;

import java.util.concurrent.atomic.*;

/**
 * Management of OS resources on server-side.
 * <p>
 * This allows initialization and creation of network objects, so that the client-side can call back (if needed)
 * on the server-side, to use these resources.
 */
class ServerResourceManager
extends OSResourceManager
{
   /** Flag required to initialize the remote server-side resources only once per JVM. */
   private static final AtomicBoolean IS_INIT = new AtomicBoolean();

   /**
    * Package-private constructor.
    */
   ServerResourceManager()
   {
      synchronized (ServerResourceManager.class)
      {
         // the native api requires the client to call the remote server even with server-side resources, 
         // so network server interfaces should be registered 
         if (!IS_INIT.get())
         {
            if (isServerSide(OsResourceType.MEMPTR))
            {
               initializeMemptrResource();
            }
            if (isServerSide(OsResourceType.LIBRARY))
            {
               initializeLibraryResource();
            }
            if (isServerSide(OsResourceType.SOCKET))
            {
               initializeSocketResource();
            }
            IS_INIT.set(true);
         }
      }
   }

   /**
    * Initialize the OS {@link OsResourceType#MEMPTR} resource.
    * <p>
    * If the {@link #isServerSide(OsResourceType)} memptr is server-side, the {@link MemoryDaemon} is proxied over
    * the network and this returns a local proxy, to be used on server-side.
    * 
    * @return   The {@link LowLevelBuffer} network or local object.
    */
   @Override
   LowLevelBuffer initializeMemptr()
   {
      LowLevelBuffer memptr = (LowLevelBuffer) resources.get(OsResourceType.MEMPTR);
      if (memptr != null)
      {
         return memptr;
      }

      if (isServerSide(OsResourceType.MEMPTR))
      {
         new MemoryDaemon(true);

         memptr = (LowLevelBuffer) RemoteObject.obtainLocalInstance(LowLevelBuffer.class, true);
      }
      else
      {
         memptr = (LowLevelBuffer) RemoteObject.obtainInstance(LowLevelBuffer.class, true);
      }
      resources.put(OsResourceType.MEMPTR, memptr);
      return memptr;
   }
   
   /**
    * Initialize the OS {@link OsResourceType#LIBRARY} resource.
    * <p>
    * If the {@link #isServerSide(OsResourceType)} library is server-side, the {@link LibraryDaemon} is proxied over
    * the network and this returns a local proxy, to be used on server-side.
    * 
    * @return   The {@link NativeAPICaller} network or local object.
    */
   @Override
   NativeAPICaller initializeLibrary()
   {
      NativeAPICaller lib = (NativeAPICaller) resources.get(OsResourceType.LIBRARY);
      if (lib != null)
      {
         return lib;
      }

      if (isServerSide(OsResourceType.LIBRARY))
      {
         new LibraryDaemon(true);

         lib = (NativeAPICaller) RemoteObject.obtainLocalInstance(NativeAPICaller.class, true);
      }
      else
      {
         lib = (NativeAPICaller) RemoteObject.obtainInstance(NativeAPICaller.class, true);
      }
      resources.put(OsResourceType.LIBRARY, lib);
      return lib;
   }
   
   /**
    * Initialize the OS {@link OsResourceType#SOCKET} resource.
    * <p>
    * If the {@link #isServerSide(OsResourceType)}} client-socket is server-side, the {@link LowLevelSocket} is
    * proxied over the network and this returns a local proxy, to be used on server-side.
    * 
    * @return   The {@link LowLevelSocket} network or local object.
    */
   @Override
   LowLevelSocket initializeSocket()
   {
      LowLevelSocket socket = (LowLevelSocket) resources.get(OsResourceType.SOCKET);
      if (socket != null)
      {
         return socket;
      }

      if (isServerSide(OsResourceType.SOCKET))
      {
         new LowLevelSocketImpl(true);

         socket = (LowLevelSocket) RemoteObject.obtainLocalInstance(LowLevelSocket.class, true);
      }
      else
      {
         socket = (LowLevelSocket) RemoteObject.obtainInstance(LowLevelSocket.class, true);
      }
      resources.put(OsResourceType.SOCKET, socket);
      return socket;
   }

   /**
    * Initialize the OS {@link OsResourceType#FILESYSTEM} resource.
    * <p>
    * If the {@link #isServerSide(OsResourceType)} file system is server-side, the {@link FileSystem} is
    * proxied over the network and this returns a local proxy, to be used on server-side.
    *
    * @return   The {@link FileSystem} network or local object.
    */
   @Override
   FileSystem initializeFileSystem()
   {
      FileSystem fs = (FileSystem) resources.get(OsResourceType.FILESYSTEM);
      if (fs != null)
      {
         return fs;
      }

      if (isServerSide(OsResourceType.FILESYSTEM))
      {
         FileSystemDaemon.getInstance(true, true);

         fs = (FileSystem) RemoteObject.obtainLocalInstance(FileSystem.class, true);
      }
      else
      {
         fs = (FileSystem) RemoteObject.obtainInstance(FileSystem.class, true);
      }
      resources.put(OsResourceType.FILESYSTEM, fs);
      return fs;
   }

   /**
    * Initialize the OS {@link OsResourceType#WEBSERVICE} resource.
    *
    * @return  The {@link WebService} network or local object.
    */
   @Override
   WebService initializeWebService()
   {
      WebService ws = (WebService) resources.get(OsResourceType.WEBSERVICE);
      if (ws != null)
      {
         return ws;
      }

      if (isServerSide(OsResourceType.WEBSERVICE))
      {
         WebServiceImpl.getInstance(true);
         ws = (WebService) RemoteObject.obtainLocalInstance(WebService.class, true);
      }
      else
      {
         ws = (WebService) RemoteObject.obtainInstance(WebService.class, true);
      }
      resources.put(OsResourceType.WEBSERVICE, ws);
      return ws;
   }

   /**
    /**
    * Get the OS {@link OsResourceType#ENVIRONMENTS} resource.
    *
    * @return   The {@link EnvironmentAccessor} network or local object.
    */
   @Override
   EnvironmentAccessor initializeEnvironments()
   {
      EnvironmentAccessor env = (EnvironmentAccessor) resources.get(OsResourceType.ENVIRONMENTS);
      if (env != null)
      {
         return env;
      }

      if (isServerSide(OsResourceType.ENVIRONMENTS))
      { 
         String storageId = SessionUtils.getStorageId();
         String fwdUser = com.goldencode.p2j.security.SecurityManager.getInstance().getUserId();
         ClientStorage clientStorage = new ClientStorageImpl(new UserPreferences(storageId, fwdUser));

         // create the network server for the server-side environments usage
         new EnvironmentDaemon(EnvironmentOps.getVersion().toStringMessage(),
                               true,
                               PlatformHelper.isUnderWindowsFamily(),
                               clientStorage);

         env = (EnvironmentAccessor) RemoteObject.obtainLocalInstance(EnvironmentAccessor.class, true);
      }
      else
      {
         env = (EnvironmentAccessor) RemoteObject.obtainInstance(EnvironmentAccessor.class, true);
      }
      resources.put(OsResourceType.ENVIRONMENTS, env);
      return env;
   }

   /**
    * Get the OS {@link OsResourceType#MAIL} resource.
    *
    * @return   The {@link RemoteEmailSender} network or local object.
    */
   @Override
   RemoteEmailSender initializeEmailSender()
   {
      RemoteEmailSender mailSender = (RemoteEmailSender) resources.get(OsResourceType.MAIL);
      if (mailSender != null)
      {
         return mailSender;
      }

      if (isServerSide(OsResourceType.MAIL))
      {
         // create the network server for the server-side mail sender usage
         new EmailDaemon(true);

         mailSender = (RemoteEmailSender) RemoteObject.obtainLocalInstance(RemoteEmailSender.class, true);
      }
      else
      {
         mailSender = (RemoteEmailSender) RemoteObject.obtainInstance(RemoteEmailSender.class, true);
      }
      resources.put(OsResourceType.MAIL, mailSender);
      return mailSender;
   }

   /**
    * Initialize the OS {@link OsResourceType#LAUNCHER} resource.
    *
    * @return   The {@link Launcher} network or local object.
    */
   @Override
   Launcher initializeProcessLauncher()
   {
      Launcher launcher = (Launcher) resources.get(OsResourceType.LAUNCHER);
      if (launcher != null)
      {
         return launcher;
      }

      if (isServerSide(OsResourceType.LAUNCHER))
      {
         // create the network server for the server-side process launching
         new ProcessDaemon(new ServerSideTerminal(), true);

         launcher = (Launcher) RemoteObject.obtainLocalInstance(Launcher.class, true);
      }
      else
      {
         launcher = (Launcher) RemoteObject.obtainInstance(Launcher.class, true);
      }
      resources.put(OsResourceType.LAUNCHER, launcher);
      return launcher;
   }

   /**
    * Initialize the OS {@link OsResourceType#STREAMS} resource.
    *
    * @return   The {@link StreamDaemon} network or local object.
    */
   @Override
   StreamHelper initializeStreamHelper()
   {
      StreamHelper streams = (StreamHelper) resources.get(OsResourceType.STREAMS);
      if (streams != null)
      {
         return streams;
      }

      if (isServerSide(OsResourceType.STREAMS))
      {
         streams = new StreamDaemon(new ServerSideTerminal());
      }
      else
      {
         streams = (StreamHelper) RemoteObject.obtainInstance(StreamHelper.class, true);
      }
      resources.put(OsResourceType.STREAMS, streams);
      return streams;
   }

   /**
    * Initialize the {@link OsResourceType#MEMPTR} resource on server-side, by creating a network proxy for the 
    * {@link MemoryDaemon}.
    */
   private static void initializeMemptrResource()
   {
      // create the network server for the server-side memory usage
      new MemoryDaemon(false);
      
      // load the FWD native libraries
      LibraryManager.init();
   }
   
   /**
    * Initialize the {@link OsResourceType#LIBRARY} resource on server-side, by creating a network proxy for the 
    * {@link LibraryDaemon}.
    */
   private static void initializeLibraryResource()
   {
      // create the network server for the server-side library usage
      new LibraryDaemon(false);
      
      // load the FWD native libraries
      LibraryManager.init();
   }
   
   /**
    * Initialize the {@link OsResourceType#SOCKET} resource on server-side, by creating a network proxy for the 
    * {@link LowLevelSocket}.
    */
   private static void initializeSocketResource()
   {
      new LowLevelSocketImpl(false);
   }
}