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.shell.ShellProcess;
022import org.crsh.shell.ShellProcessContext;
023import org.crsh.shell.ShellResponse;
024
025import java.util.logging.Level;
026
027abstract class CRaSHProcess implements ShellProcess {
028
029  /** . */
030  protected final CRaSHSession crash;
031
032  /** . */
033  protected final String request;
034
035  /** . */
036  private volatile Thread thread;
037
038  /** . */
039  private volatile boolean cancelled;
040
041  protected CRaSHProcess(CRaSHSession crash, String request) {
042    this.crash = crash;
043    this.request = request;
044  }
045
046  public void execute(ShellProcessContext processContext) {
047    ClassLoader previous = crash.setCRaSHLoader();
048    try {
049      ShellResponse resp;
050      thread = Thread.currentThread();
051
052      //
053      String userName = crash.user != null ? crash.user.getName() : "unauthenticated";
054      CRaSHSession.accessLog.log(Level.FINE, "User " + userName + " executes " + request);
055
056      //
057      try {
058        try {
059          resp = doInvoke(processContext);
060          if (Thread.interrupted() || cancelled) {
061            throw new InterruptedException("like a goto");
062          }
063        }
064        catch (InterruptedException e) {
065          resp = ShellResponse.cancelled();
066        }
067      } catch (Throwable t) {
068        resp = ShellResponse.internalError("Unexpected error when executing process", t);
069      } finally {
070        thread = null;
071      }
072
073      //
074      processContext.end(resp);
075
076      //
077      if (resp instanceof ShellResponse.Error) {
078        ShellResponse.Error error = (ShellResponse.Error)resp;
079        Throwable t = error.getThrowable();
080        if (t != null) {
081          CRaSHSession.log.log(Level.SEVERE, "Error while evaluating request '" + request + "' " + error.getMessage(), t);
082        } else {
083          CRaSHSession.log.log(Level.SEVERE, "Error while evaluating request '" + request + "' " + error.getMessage());
084        }
085      }
086    }
087    finally {
088      crash.setPreviousLoader(previous);
089    }
090  }
091
092  abstract ShellResponse doInvoke(ShellProcessContext context) throws InterruptedException;
093
094  public void cancel() {
095    ClassLoader previous = crash.setCRaSHLoader();
096    try {
097      Thread t = thread;
098      if (t != null) {
099        t.interrupt();
100      }
101      cancelled = true;
102    }
103    finally {
104      crash.setPreviousLoader(previous);
105    }
106  }
107}