Pipeline.java

/**
 * $Id$
 * $Date$
 *
 */

package org.xmlsh.sh.core;

import java.io.PrintWriter;
import java.util.ArrayList;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.xmlsh.sh.shell.Shell;
import org.xmlsh.sh.shell.ShellThread;
import org.xmlsh.util.PipedPort;
import org.xmlsh.util.PipedStreamPort;
import org.xmlsh.util.PipedXDMPort;

public class Pipeline extends CommandExpr {

  private ArrayList<CommandExpr> mList = new ArrayList<CommandExpr>();

  @Override
  public boolean isSimple() {
    return false;
  }

  static Logger mLogger = LogManager.getLogger();

  private boolean mBang;

  public Pipeline(boolean bBang) {
    mBang = bBang;
  }

  /**
   * @param bang
   *          the bang to set
   */
  public void setBang(boolean bang) {
    mBang = bang;
  }

  public boolean isBang() {
    return mBang;
  }

  /**
   * @param e
   * @return
   * @see java.util.ArrayList#add(java.lang.Object)
   */
  public boolean add(CommandExpr e) {
    if(!e.hasLocation())
      setLocation(e);
    return mList.add(e);
  }

  @Override
  public void print(PrintWriter out, boolean bExec) {
    // Dont print pipelines in exec mode
    if(bExec)
      return;

    if(isBang())
      out.print("! ");

    int n = mList.size();
    for(ICommandExpr c : mList) {
      c.print(out, bExec);
      if(n-- > 1)
        out.print("|");

    }
  }

  /*
   * (non-Javadoc)
   * 
   * @see org.xmlsh.sh.core.Command#exec(org.xmlsh.core.XEnvironment)
   */
  @Override
  public int exec(Shell shell) throws Exception {

    mLogger.entry(shell);
    int ncmds = mList.size();

    ArrayList<ShellThread> threads = new ArrayList<ShellThread>();

    PipedPort pipes[] = null;
    /*
     * Use XML Pipes only if xpipe option is set
     */
    if(ncmds > 1) {
      if(!shell.getOpts().mXPipe)
        pipes = PipedStreamPort.getPipes(ncmds - 1);
      else

        // pipes=
        // PipedXMLPort.getPipes(ncmds-1,shell.getSerializeOpts());
        pipes = PipedXDMPort.getPipes(ncmds - 1,
            shell.getSerializeOpts());
    }

    /*
     * Setup all but LAST command as seperate threads The last thread runs
     * within the current shell
     */
    for(int pi = 0; pi < ncmds - 1; pi++) {
      Shell sh = shell.clone(); // clone shell for execution
      try {
        CommandExpr c = mList.get(pi);
        if(pi > 0)
          // Set input to pipe for all but the first
          sh.getEnv().setStdin(pipes[pi - 1].getInput());
        // Set the output
        sh.getEnv().setStdout(pipes[pi].getOutput());
        ShellThread sht = new ShellThread(shell.getThreadGroup(), sh,
            null, c);
        sh = null;

        sht.start();
        threads.add(sht);
      } finally {
        if(sh != null) {
          sh.close();
          mLogger.trace("Closing shell due to exception", sh);
        }
      }
    }

    if(ncmds > 1)
      shell.getEnv().saveIO();
    try {

      if(ncmds > 1)
        shell.getEnv().setStdin(pipes[ncmds - 2].getInput());

      CommandExpr c = mList.get(ncmds - 1);

      // Protect ! commands as a condition
      int ret = mBang ? shell.execCondition(c) : shell.exec(c,
          this.getSourceLocation());

      // if( ncmds > 1 )
      // pipes[0].getOutput().close();

      for(ShellThread sht : threads)
        sht.join();

      return mBang ? (ret == 0 ? 1 : 0) : ret;

    } finally {
      if(ncmds > 1)
        shell.getEnv().restoreIO();

    }

  }

}
//
//
// Copyright (C) 2008-2014 David A. Lee.
//
// The contents of this file are subject to the "Simplified BSD License" (the
// "License");
// you may not use this file except in compliance with the License. You may
// obtain a copy of the
// License at http://www.opensource.org/licenses/bsd-license.php
//
// Software distributed under the License is distributed on an "AS IS" basis,
// WITHOUT WARRANTY OF ANY KIND, either express or implied.
// See the License for the specific language governing rights and limitations
// under the License.
//
// The Original Code is: all this file.
//
// The Initial Developer of the Original Code is David A. Lee
//
// Portions created by (your name) are Copyright (C) (your legal entity). All
// Rights Reserved.
//
// Contributor(s): none.
//