/* A polymorphic select, which routes specified input channels to the output.
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Code review issue: This actor reads data in prefire.
*/
//////////////////////////////////////////////////////////////////////////
//// Select
package ptolemy.backtrack.automatic.ptolemy.actor.lib;
import java.lang.Object;
import ptolemy.actor.TypedIOPort;
import ptolemy.actor.lib.Transformer;
import ptolemy.backtrack.Checkpoint;
import ptolemy.backtrack.Rollbackable;
import ptolemy.backtrack.util.CheckpointRecord;
import ptolemy.backtrack.util.FieldRecord;
import ptolemy.data.IntToken;
import ptolemy.data.type.BaseType;
import ptolemy.kernel.CompositeEntity;
import ptolemy.kernel.util.IllegalActionException;
import ptolemy.kernel.util.NameDuplicationException;
import ptolemy.kernel.util.StringAttribute;
/**
* <p>A polymorphic select, which routes specified input channels to the
* output. This actor has two input ports, the <i>input</i> port for
* data, and the <i>control</i> port to select which input channel to
* read. 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 input channel that should be read next. If an
* input token is available on the specified channel of the <i>input</i>
* port, then that token is read and sent to the output.
* </p><p> The actor indicates a willingness to fire in its prefire() method
* if there is an input available on the channel specified by the most
* recently seen token on the <i>control</i> port. If no token has ever
* been received on the <i>control</i> port, then channel zero is assumed
* to be the one to read. If the value of the most recently received
* token on the <i>control</i> port is out of range (less than zero, or
* greater than or equal to the width of the input), then the actor will
* not fire() (although it will continue to consume tokens on the
* <i>control</i> port in its prefire() method).
* </p><p> This actor is similar to the Multiplexor actor, except that it
* never discards input tokens. Tokens on channels that are not selected
* are not consumed.
* </p><p> Note that in the DE domain, where this actor is commonly used, if
* a new value is given to the <i>control</i> port, then all previously
* unread input tokens on the specified input channel will be read at the
* same firing time, in the order in which they arrived.</p>
* @author Edward A. Lee
* @version $Id$
* @since Ptolemy II 1.0
* @Pt.ProposedRating Green (neuendor)
* @Pt.AcceptedRating Yellow (liuj)
*/
public class Select extends Transformer implements Rollbackable {
protected transient Checkpoint $CHECKPOINT = new Checkpoint(this);
// Put the control input on the bottom of the actor.
///////////////////////////////////////////////////////////////////
//// ports and parameters ////
///////////////////////////////////////////////////////////////////
//// public methods ////
/**
* Input port for control tokens, which specify the output channel
* to produce data on. The type is int.
*/
public TypedIOPort control;
// Redo this check in case the control has changed since prefire().
///////////////////////////////////////////////////////////////////
//// private variables ////
// The most recently read control token.
private int _control = 0;
/**
* 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 Select(CompositeEntity container, String name) throws IllegalActionException, NameDuplicationException {
super(container, name);
input.setMultiport(true);
control = new TypedIOPort(this, "control", true, false);
control.setTypeEquals(BaseType.INT);
StringAttribute controlCardinal = new StringAttribute(control, "_cardinal");
controlCardinal.setExpression("SOUTH");
}
/**
* Read an input token from the specified input channel and produce
* it on the output.
* @exception IllegalActionException If there is no director.
*/
public void fire() throws IllegalActionException {
super.fire();
if (input.hasToken(_control)) {
output.send(0, input.get(_control));
}
}
/**
* Initialize this actor so that channel zero of <i>input</i> is read
* from 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(0);
}
/**
* Read a control token, if there is one, and check to see
* whether an input is available on the input channel specified by
* the most recent control token, if it is in range.
* Return false if there is no input token to read.
* Otherwise, return whatever the superclass returns.
* @return True if the actor is ready to fire.
* @exception IllegalActionException If there is no director.
*/
public boolean prefire() throws IllegalActionException {
if (control.hasToken(0)) {
$ASSIGN$_control(((IntToken)control.get(0)).intValue());
}
if ((_control < 0) || (_control > input.getWidth())||!input.hasToken(_control)) {
return false;
}
return super.prefire();
}
private final int $ASSIGN$_control(int 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
};
}