/* A simple sink actor that consumes and discards input tokens.
Copyright (c) 1998-2009 The Regents of the University of California.
All rights reserved.
Permission is hereby granted, without written agreement and without
license or royalty fees, to use, copy, modify, and distribute this
software and its documentation for any purpose, provided that the above
copyright notice and the following two paragraphs appear in all copies
of this software.
IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY
FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF
SUCH DAMAGE.
THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE
PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF
CALIFORNIA HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES,
ENHANCEMENTS, OR MODIFICATIONS.
PT_COPYRIGHT_VERSION_2
COPYRIGHTENDKEY
*/
package ptolemy.actor.lib;
import java.net.URL;
import ptolemy.kernel.CompositeEntity;
import ptolemy.kernel.util.Configurable;
import ptolemy.kernel.util.IllegalActionException;
import ptolemy.kernel.util.NameDuplicationException;
//////////////////////////////////////////////////////////////////////////
//// Discard
/**
A simple sink actor that consumes and discards input tokens.
<p>This actor is useful in situations where the value of an output is not
needed, but for some reason, the output cannot be left unconnected.
Also, when manipulating bus signals, this actor is useful if values
in the middle of the bus need to be discarded. Leaving the bus
unconnected in the middle will not work because no channel is allocated
to an unconnected relation in a bus.
@author Edward A. Lee, contributors: Christopher Brooks, Brian Hudson
@version $Id$
@since Ptolemy II 1.0
@Pt.ProposedRating Yellow (eal)
@Pt.AcceptedRating Yellow (ssachs)
*/
public class Discard extends Sink implements Configurable {
/** Construct an actor with an input multiport.
* @param container The container.
* @param name The name of this actor.
* @exception IllegalActionException If the actor cannot be contained
* by the proposed container.
* @exception NameDuplicationException If the container already has an
* actor with this name.
*/
public Discard(CompositeEntity container, String name)
throws NameDuplicationException, IllegalActionException {
super(container, name);
}
///////////////////////////////////////////////////////////////////
//// public methods ////
/** Do nothing, as this actor is not actually configurable.
* <p>This class implements {@link ptolemy.kernel.util.Configurable}
* so that the MoML filters can replace graphical actors that
* implement Configurable with this actor. Note that the actors
* to be replaced must have an input port named <i>input</i>, so
* not all Configurable actors can be replaced with this actor.
* @param base Ignored.
* @param source Ignored.
* @param text Ignored.
* @exception Exception Not thrown in this base class.
*/
public void configure(URL base, String source, String text)
throws Exception {
}
/** Read one token from each input channel and discard it.
* If there is no input on a channel, then skip that channel, doing
* nothing with it.
* @exception IllegalActionException If there is no director.
*/
public void fire() throws IllegalActionException {
super.fire();
int width = input.getWidth();
for (int i = 0; i < width; i++) {
if (input.hasToken(i)) {
input.get(i);
}
}
}
/** Return null because this actor is not actually configurable.
* @return Always return null.
*/
public String getConfigureSource() {
return null;
}
/** Return null because this actor is not actually configurable.
* @return Always return null.
*/
public String getConfigureText() {
return null;
}
}