001/* An actor that converts 32 consecutive BooleanTokens to an IntToken
002
003 Copyright (c) 1998-2014 The Regents of the University of California.
004 All rights reserved.
005 Permission is hereby granted, without written agreement and without
006 license or royalty fees, to use, copy, modify, and distribute this
007 software and its documentation for any purpose, provided that the above
008 copyright notice and the following two paragraphs appear in all copies
009 of this software.
010
011 IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY
012 FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
013 ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
014 THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF
015 SUCH DAMAGE.
016
017 THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
018 INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
019 MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE
020 PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF
021 CALIFORNIA HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES,
022 ENHANCEMENTS, OR MODIFICATIONS.
023
024 PT_COPYRIGHT_VERSION_2
025 COPYRIGHTENDKEY
026
027 */
028package ptolemy.domains.sdf.lib;
029
030import ptolemy.data.BooleanToken;
031import ptolemy.data.IntToken;
032import ptolemy.data.Token;
033import ptolemy.data.expr.Parameter;
034import ptolemy.data.type.BaseType;
035import ptolemy.kernel.CompositeEntity;
036import ptolemy.kernel.util.Attribute;
037import ptolemy.kernel.util.IllegalActionException;
038import ptolemy.kernel.util.NameDuplicationException;
039
040///////////////////////////////////////////////////////////////////
041/// BitsToInt
042
043/**
044 This actor converts a sequence of BooleanTokens into a single IntToken.
045 The number of Boolean tokens is specified by the <i>numberOfBits</i>
046 parameter and should be a positive integer not larger than 32. Let <i>k</i>
047 denotes the value of the <i>numberOfBits</i> parameter. The output
048 integer is ranged from -2<sup><i>k</i></sup> to 2<sup><i>k</i></sup> - 1.
049
050 The first boolean token received indicates the sign of the integer. If
051 it is "false", the output integer is a non-negative number. If it is "true",
052 the output integer is a negative number. The least significant bit is
053 the last boolean token received.
054
055 @author Michael Leung
056 @version $Id$
057 @since Ptolemy II 0.4
058 @Pt.ProposedRating Green (neuendor)
059 @Pt.AcceptedRating Yellow (neuendor)
060 */
061public class BitsToInt extends SDFConverter {
062    /** Construct an actor with the given container and name.
063     *  @param container The container.
064     *  @param name The name of this actor.
065     *  @exception IllegalActionException If the actor cannot be contained
066     *   by the proposed container.
067     *  @exception NameDuplicationException If the container already has an
068     *   actor with this name.
069     */
070    public BitsToInt(CompositeEntity container, String name)
071            throws NameDuplicationException, IllegalActionException {
072        super(container, name);
073
074        numberOfBits = new Parameter(this, "numberOfBits");
075        numberOfBits.setExpression("32");
076
077        input_tokenConsumptionRate.setExpression("numberOfBits");
078
079        input.setTypeEquals(BaseType.BOOLEAN);
080
081        output.setTypeEquals(BaseType.INT);
082    }
083
084    ///////////////////////////////////////////////////////////////////
085    ////                         parameters                        ////
086
087    /** The number of bits that is converted to the output integer.
088     *  It should be a positive integer no more than 32.
089     */
090    public Parameter numberOfBits;
091
092    ///////////////////////////////////////////////////////////////////
093    ////                         public methods                    ////
094
095    /** If the argument is the <i>numberOfBits</i> parameter, then
096     *  set the production rate of the output port.
097     *  @param attribute The attribute that has changed.
098     *  @exception IllegalActionException If the parameter is out of range.
099     */
100    @Override
101    public void attributeChanged(Attribute attribute)
102            throws IllegalActionException {
103        if (attribute == numberOfBits) {
104            int rate = ((IntToken) numberOfBits.getToken()).intValue();
105
106            if (rate < 1 || rate > 32) {
107                throw new IllegalActionException(this,
108                        "Invalid number of bits: " + rate);
109            }
110        } else {
111            super.attributeChanged(attribute);
112        }
113    }
114
115    /** Consume <i>numberOfBits</i> BooleanTokens on the input.
116     *  Output a single IntToken which is representing by the
117     *  BooleanTokens.
118     *  The first token consumed is the most significant bit (The sign bit).
119     *  The last token consumed is the least significant bit
120     *  @exception IllegalActionException If there is no director.
121     */
122    @Override
123    public final void fire() throws IllegalActionException {
124        super.fire();
125
126        int rate = ((IntToken) numberOfBits.getToken()).intValue();
127        Token[] bits /* Dead Store: = new BooleanToken[rate]*/;
128        bits = input.get(0, rate);
129
130        int integer = 0;
131
132        for (int i = 1; i < rate; i++) {
133            integer = integer << 1;
134
135            if (((BooleanToken) bits[i]).booleanValue()) {
136                integer += 1;
137            }
138        }
139
140        if (((BooleanToken) bits[0]).booleanValue()) {
141            //convert integer to negative value.
142            integer = integer - (1 << rate - 1);
143        }
144
145        IntToken value = new IntToken(integer);
146        output.send(0, value);
147    }
148}