TDLAction.java

/*
@Copyright (c) 2008-2009 The Regents of the University of California.
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 */
package ptolemy.domains.tdl.kernel;

import java.util.Comparator;

import ptolemy.actor.util.Time;

/**
 * A TDL action. Used in the TDLActionsGraph.
 * @author Patricia Derler
 * @version $Id$
 * @since Ptolemy II 7.1
 *
 */
public class TDLAction {

    /**
     * Create a new TDLGraphNode.
     * @param time Time stamp the TDL action has to be done at.
     * @param actionType Type of TDL action.
     * @param actor Actor on which the TDL action has to be performed on.
     */
    public TDLAction(Time time, int actionType, Object actor) {
        this.time = time;
        this.actionType = actionType;
        this.object = actor;
    }

    /**
     * Write output of a task.
     */
    public static final int WRITEOUTPUT = 0;

    /**
     * Write actuator which is the output of a TDLModule.
     */
    public static final int WRITEACTUATOR = 1;

    /**
     * Test a mode switch guard and execute the mode switch if the guard
     * evaluates to true.
     */
    public static final int MODESWITCH = 2;

    /**
     * If a mode switch is not taken, this is the next action. It does not do anything but is
     * required for the TDL ActionsGraph.
     */
    public static final int AFTERMODESWITCH = 3;

    /**
     * Read a sensor value which is the input of a TDLModule.
     */
    public static final int READSENSOR = 4;

    /**
     * Read the input of a task.
     */
    public static final int READINPUT = 5;

    /**
     * Execute a task.
     */
    public static final int EXECUTETASK = 6;

    /**
     * The action after a task is output.
     */
    public static final int AFTERTASKOUTPUTS = 7;

    /**
     * Time stamp for the TDL action.
     */
    public Time time;

    /**
     * Type of TDL action. This is one of the constants defined above.
     */
    public int actionType;

    /**
     * Actor the TDL action has to be performed on.
     */
    public Object object;

    ///////////////////////////////////////////////////////////////////
    ////                         public methods                    ////

    @Override
    public String toString() {
        return actionType + "@" + time + "@" + object;
    }

    @Override
    public boolean equals(Object obj) {
        if (obj instanceof TDLAction) {
            TDLAction action = (TDLAction) obj;
            if ((this.time.equals(action.time))
                    && (this.object == action.object)
                    && (this.actionType == action.actionType)) {
                return true;
            }
        }
        return false;
    }

    /** Return a hash code value for this action.
     *  @return A hash code value for this token.
     */
    public int hashCode() {
        // See http://www.geocities.com/technofundo/tech/java/equalhash.html
        // for suggestions on hashCode
        return 31 + time.hashCode() + actionType + object.hashCode();
    }

    /**
     * Return true if two actions are the same.
     * @param action The action to compare against this action
     * @param modePeriod The mode period.
     * @return true if the times are equal (==), the TDL actions are
     * equal (==) and the action times are equal (==).
     */
    public boolean sameActionAs(TDLAction action, Time modePeriod) {
        long time1 = this.time.getLongValue() % modePeriod.getLongValue();
        long time2 = action.time.getLongValue() % modePeriod.getLongValue();
        if (time1 == time2 && (this.object == action.object)
                && (this.actionType == action.actionType)) {
            return true;
        }
        return false;
    }

    /**
     * A class that compares two TDL actions.
     */
    public static class TDLActionComparator implements Comparator {

        /**
         * Compare two TDLEvents. Two TDL Events are the same if all
         * attributes are the same: timestamp, actionType and actor. For
         * comparison of an actor, the actor name which has to be unique
         * in the model is used.
         * @param event1 First event.
         * @param event2 Second event.
         * @return The result of the comparison of the two TDL events.
         */
        public int compare(Object event1, Object event2) {
            TDLAction tdlEvent1 = (TDLAction) event1;
            TDLAction tdlEvent2 = (TDLAction) event2;
            long compareTime = tdlEvent1.time.compareTo(tdlEvent2.time);
            if (compareTime != 0) {
                return (int) compareTime;
            } else if (tdlEvent1.actionType != tdlEvent2.actionType) {
                return tdlEvent1.actionType - tdlEvent2.actionType;
            } else {
                return tdlEvent1.object.toString().compareTo(
                        tdlEvent2.object.toString());
            }
        }
    }
}