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 */
019package org.crsh.shell.impl.command;
020
021import org.crsh.keyboard.KeyHandler;
022import org.crsh.shell.ShellProcess;
023import org.crsh.shell.ShellProcessContext;
024import org.crsh.shell.ShellResponse;
025
026import java.util.logging.Level;
027
028abstract 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}