001    /*
002     * Copyright (C) 2012 eXo Platform SAS.
003     *
004     * This is free software; you can redistribute it and/or modify it
005     * under the terms of the GNU Lesser General Public License as
006     * published by the Free Software Foundation; either version 2.1 of
007     * the License, or (at your option) any later version.
008     *
009     * This software is distributed in the hope that it will be useful,
010     * but WITHOUT ANY WARRANTY; without even the implied warranty of
011     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
012     * Lesser General Public License for more details.
013     *
014     * You should have received a copy of the GNU Lesser General Public
015     * License along with this software; if not, write to the Free
016     * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
017     * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
018     */
019    package org.crsh.shell.impl.command;
020    
021    import org.crsh.keyboard.KeyHandler;
022    import org.crsh.shell.ShellProcess;
023    import org.crsh.shell.ShellProcessContext;
024    import org.crsh.shell.ShellResponse;
025    
026    import java.util.logging.Level;
027    
028    abstract class CRaSHProcess implements ShellProcess {
029    
030      /** . */
031      protected final CRaSHSession crash;
032    
033      /** . */
034      protected final String request;
035    
036      /** . */
037      private volatile Thread thread;
038    
039      /** . */
040      private volatile boolean cancelled;
041    
042      protected CRaSHProcess(CRaSHSession crash, String request) {
043        this.crash = crash;
044        this.request = request;
045      }
046    
047      public void execute(ShellProcessContext processContext) {
048        ClassLoader previous = crash.setCRaSHLoader();
049        try {
050          ShellResponse resp;
051          thread = Thread.currentThread();
052    
053          //
054          String userName = crash.user != null ? crash.user.getName() : "unauthenticated";
055          CRaSHSession.accessLog.log(Level.FINE, "User " + userName + " executes " + request);
056    
057          //
058          try {
059            try {
060              resp = doInvoke(processContext);
061              if (Thread.interrupted() || cancelled) {
062                throw new InterruptedException("like a goto");
063              }
064            }
065            catch (InterruptedException e) {
066              // Preserve interrupt status
067              Thread.currentThread().interrupt();
068              resp = ShellResponse.cancelled();
069            }
070          } catch (Throwable t) {
071            resp = ShellResponse.internalError("Unexpected error when executing process", t);
072          } finally {
073            thread = null;
074          }
075    
076          //
077          processContext.end(resp);
078    
079          //
080          if (resp instanceof ShellResponse.Error) {
081            ShellResponse.Error error = (ShellResponse.Error)resp;
082            Throwable t = error.getThrowable();
083            if (t != null) {
084              CRaSHSession.log.log(Level.SEVERE, "Error while evaluating request '" + request + "' " + error.getMessage(), t);
085            } else {
086              CRaSHSession.log.log(Level.SEVERE, "Error while evaluating request '" + request + "' " + error.getMessage());
087            }
088          }
089        }
090        finally {
091          crash.setPreviousLoader(previous);
092        }
093      }
094    
095      @Override
096      public KeyHandler getKeyHandler() {
097        return null;
098      }
099    
100      abstract ShellResponse doInvoke(ShellProcessContext context) throws InterruptedException;
101    
102      public void cancel() {
103        ClassLoader previous = crash.setCRaSHLoader();
104        try {
105          Thread t = thread;
106          if (t != null) {
107            t.interrupt();
108          }
109          cancelled = true;
110        }
111        finally {
112          crash.setPreviousLoader(previous);
113        }
114      }
115    }