/* Split a stream into two according to a boolean control signal.
Copyright (c) 1997-2009 The Regents of the University of California.
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This is similar to Switch and could be design/code reviewed at the same time.
*/
//////////////////////////////////////////////////////////////////////////
//// BooleanSwitch
package ptolemy.backtrack.automatic.ptolemy.actor.lib;
import java.lang.Object;
import ptolemy.actor.TypedAtomicActor;
import ptolemy.actor.TypedIOPort;
import ptolemy.backtrack.Checkpoint;
import ptolemy.backtrack.Rollbackable;
import ptolemy.backtrack.util.CheckpointRecord;
import ptolemy.backtrack.util.FieldRecord;
import ptolemy.data.BooleanToken;
import ptolemy.data.Token;
import ptolemy.data.type.BaseType;
import ptolemy.kernel.CompositeEntity;
import ptolemy.kernel.util.IllegalActionException;
import ptolemy.kernel.util.NameDuplicationException;
import ptolemy.kernel.util.StringAttribute;
import ptolemy.kernel.util.Workspace;
/**
* Split an input stream onto two output ports depending on a
* boolean control input. In an
* iteration, if an input token is available at the <i>control</i> input,
* that token is read, and its value is noted. Its value specifies the
* output port that should be written to in this and subsequent iterations,
* until another <i>control</i> input is provided. If no <i>control</i>
* input is provided, then the inputs are routed to the <i>falseOutput</i> port.
* In each iteration, at most one token on each channel of the <i>input</i> port
* is read and sent to the corresponding channel of the
* <i>trueOutput</i> port or the <i>falseOutput</i> port, depending on the
* most recently received <i>control</i> input.
* If the input has width greater than an output port, then
* some input tokens will be discarded (those on input channels for which
* there is no corresponding output channel).
* Because tokens are
* immutable, the same Token is sent to the output, rather than a copy.
* The <i>input</i> port may receive Tokens of any type.
* <p>Note that the this actor may be used in Synchronous Dataflow (SDF)
* models, but only under certain circumstances. Specifically, downstream
* actors will be fired whether a token is sent to them or not.
* This will only work if the downstream actors specifically check to
* see whether input tokens are available.
* @author Steve Neuendorffer
* @version $Id$
* @since Ptolemy II 2.0
* @Pt.ProposedRating Green (neuendor)
* @Pt.AcceptedRating Red (neuendor)
*/
public class BooleanSwitch extends TypedAtomicActor implements Rollbackable {
protected transient Checkpoint $CHECKPOINT = new Checkpoint(this);
// Put the control input on the bottom of the actor.
///////////////////////////////////////////////////////////////////
//// ports and parameters ////
/**
* Input that selects one of the other input ports. The type is
* boolean.
*/
public TypedIOPort control;
/**
* The input port. The type can be anything. This is a multiport,
* and input tokens on all channels are routed to corresponding
* channels on the output port, if there are such channels.
*/
public TypedIOPort input;
/**
* Output for tokens on the true path. The type is at least the
* type of the input.
*/
public TypedIOPort trueOutput;
/**
* Output for tokens on the false path. The type is at least the
* type of the input.
*/
public TypedIOPort falseOutput;
///////////////////////////////////////////////////////////////////
//// public methods ////
///////////////////////////////////////////////////////////////////
//// private variables ////
// The most recently read control token.
private boolean _control = false;
/**
* Construct an actor in the specified container with the specified
* name.
* @param container The container.
* @param name The name of this actor within the container.
* @exception IllegalActionException If the actor cannot be contained
* by the proposed container.
* @exception NameDuplicationException If the name coincides with
* an actor already in the container.
*/
public BooleanSwitch(CompositeEntity container, String name) throws IllegalActionException, NameDuplicationException {
super(container, name);
input = new TypedIOPort(this, "input", true, false);
input.setMultiport(true);
control = new TypedIOPort(this, "control", true, false);
control.setTypeEquals(BaseType.BOOLEAN);
trueOutput = new TypedIOPort(this, "trueOutput", false, true);
falseOutput = new TypedIOPort(this, "falseOutput", false, true);
trueOutput.setTypeAtLeast(input);
falseOutput.setTypeAtLeast(input);
trueOutput.setMultiport(true);
falseOutput.setMultiport(true);
trueOutput.setWidthEquals(input, true);
falseOutput.setWidthEquals(input, true);
StringAttribute controlCardinal = new StringAttribute(control, "_cardinal");
controlCardinal.setExpression("SOUTH");
}
/**
* Clone this actor into the specified workspace. The new actor is
* <i>not</i> added to the directory of that workspace (you must do this
* yourself if you want it there).
* The result is a new actor with the same ports as the original, but
* no connections and no container. A container must be set before
* much can be done with this actor.
* @param workspace The workspace for the cloned object.
* @exception CloneNotSupportedException If cloned ports cannot have
* as their container the cloned entity (this should not occur), or
* if one of the attributes cannot be cloned.
* @return A new ComponentEntity.
*/
public Object clone(Workspace workspace) throws CloneNotSupportedException {
BooleanSwitch newObject = (BooleanSwitch)super.clone(workspace);
newObject.trueOutput.setTypeAtLeast(newObject.input);
newObject.falseOutput.setTypeAtLeast(newObject.input);
newObject.trueOutput.setWidthEquals(newObject.input, true);
newObject.falseOutput.setWidthEquals(newObject.input, true);
return newObject;
}
/**
* Read a token from each input port. If the token from the
* <i>control</i> input is true, then output the token consumed from the
* <i>input</i> port on the <i>trueOutput</i> port,
* otherwise output the token on the <i>falseOutput</i> port.
* @exception IllegalActionException If there is no director.
*/
public void fire() throws IllegalActionException {
super.fire();
if (control.hasToken(0)) {
$ASSIGN$_control(((BooleanToken)control.get(0)).booleanValue());
}
for (int i = 0; i < input.getWidth(); i++) {
if (input.hasToken(i)) {
Token token = input.get(i);
if (_control) {
if (i < trueOutput.getWidth()) {
trueOutput.send(i, token);
}
} else {
if (i < falseOutput.getWidth()) {
falseOutput.send(i, token);
}
}
}
}
}
/**
* Initialize this actor so that the <i>falseOutput</i> is written
* to until a token arrives on the <i>control</i> input.
* @exception IllegalActionException If the parent class throws it.
*/
public void initialize() throws IllegalActionException {
super.initialize();
$ASSIGN$_control(false);
}
private final boolean $ASSIGN$_control(boolean newValue) {
if ($CHECKPOINT != null && $CHECKPOINT.getTimestamp() > 0) {
$RECORD$_control.add(null, _control, $CHECKPOINT.getTimestamp());
}
return _control = newValue;
}
public void $COMMIT(long timestamp) {
FieldRecord.commit($RECORDS, timestamp, $RECORD$$CHECKPOINT.getTopTimestamp());
$RECORD$$CHECKPOINT.commit(timestamp);
}
public void $RESTORE(long timestamp, boolean trim) {
_control = $RECORD$_control.restore(_control, timestamp, trim);
if (timestamp <= $RECORD$$CHECKPOINT.getTopTimestamp()) {
$CHECKPOINT = $RECORD$$CHECKPOINT.restore($CHECKPOINT, this, timestamp, trim);
FieldRecord.popState($RECORDS);
$RESTORE(timestamp, trim);
}
}
public final Checkpoint $GET$CHECKPOINT() {
return $CHECKPOINT;
}
public final Object $SET$CHECKPOINT(Checkpoint checkpoint) {
if ($CHECKPOINT != checkpoint) {
Checkpoint oldCheckpoint = $CHECKPOINT;
if (checkpoint != null) {
$RECORD$$CHECKPOINT.add($CHECKPOINT, checkpoint.getTimestamp());
FieldRecord.pushState($RECORDS);
}
$CHECKPOINT = checkpoint;
oldCheckpoint.setCheckpoint(checkpoint);
checkpoint.addObject(this);
}
return this;
}
protected transient CheckpointRecord $RECORD$$CHECKPOINT = new CheckpointRecord();
private transient FieldRecord $RECORD$_control = new FieldRecord(0);
private transient FieldRecord[] $RECORDS = new FieldRecord[] {
$RECORD$_control
};
}