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10 package nl.tudelft.simulation.dsol.interpreter.operations;
11
12 import java.io.DataInput;
13 import java.io.IOException;
14 import java.util.ArrayList;
15 import java.util.List;
16
17 import nl.tudelft.simulation.dsol.interpreter.LocalVariable;
18 import nl.tudelft.simulation.dsol.interpreter.OperandStack;
19 import nl.tudelft.simulation.dsol.interpreter.classfile.Constant;
20
21 /***
22 * The TABLESWITCH operation as defined in <a
23 * href="http://java.sun.com/docs/books/vmspec/2nd-edition/html/Instructions2.doc14.html">
24 * http://java.sun.com/docs/books/vmspec/2nd-edition/html/Instructions2.doc14.html
25 * </a>.
26 * <p>
27 * (c) copyright 2003 <a href="http://www.simulation.tudelft.nl">Delft
28 * University of Technology </a>, the Netherlands. <br>
29 * See for project information <a
30 * href="http://www.simulation.tudelft.nl">www.simulation.tudelft.nl </a> <br>
31 * License of use: <a href="http://www.gnu.org/copyleft/gpl.html">General Public
32 * License (GPL) </a>, no warranty <br>
33 *
34 * @author <a href="http://www.tbm.tudelft.nl/webstaf/peterja/index.htm">Peter
35 * Jacobs </a><a
36 * href="http://www.tbm.tudelft.nl/webstaf/alexandv/index.htm">Alexander
37 * Verbraeck </a>
38 * @version 1.3 Apr 6, 2004
39 * @since 1.4
40 */
41 public class TABLESWITCH extends JumpOperation
42 {
43 /*** OP refers to the operand code */
44 public static final int OP = 170;
45
46 /*** the byteLength of this statement */
47 private int byteLength = 0;
48
49 /*** the start position of the table */
50 private int lowValue = -1;
51
52 /*** the end position of the table */
53 private int highValue = -1;
54
55 /*** the offset table */
56 private List offsets = new ArrayList();
57
58 /***
59 * constructs a new TABLESWITCH
60 *
61 * @param dataInput the dataInput
62 * @param padding the number of bytes to pad
63 * @throws IOException on IOfailure
64 */
65 public TABLESWITCH(final DataInput dataInput, final int padding)
66 throws IOException
67 {
68 super();
69
70
71 if (padding > 0)
72 {
73 dataInput.skipBytes(padding);
74 this.byteLength = this.byteLength + padding;
75 }
76
77
78 this.offsets.add(new Integer(dataInput.readInt()));
79 this.lowValue = dataInput.readInt();
80 this.highValue = dataInput.readInt();
81 int entries = this.highValue - this.lowValue + 1;
82 this.byteLength = this.byteLength + 12;
83 for (int i = 0; i < entries; i++)
84 {
85 Integer offset = new Integer(dataInput.readInt());
86 this.offsets.add(offset);
87 this.byteLength = this.byteLength + 4;
88 }
89 }
90
91 /***
92 * @see nl.tudelft.simulation.dsol.interpreter.operations.JumpOperation
93 * #execute(nl.tudelft.simulation.dsol.interpreter.OperandStack,
94 * nl.tudelft.simulation.dsol.interpreter.classfile.Constant[],
95 * nl.tudelft.simulation.dsol.interpreter.LocalVariable[])
96 */
97 public int execute(final OperandStack stack, final Constant[] constantPool,
98 final LocalVariable[] localVariables)
99 {
100 int index = ((Integer) stack.pop()).intValue();
101 int offset = -1;
102 if (index < this.lowValue || index > this.highValue)
103 {
104 offset = ((Integer) this.offsets.get(0)).intValue();
105 } else
106 {
107 offset = ((Integer) this.offsets.get(index - this.lowValue + 1))
108 .intValue();
109 }
110 return offset;
111 }
112
113 /***
114 * @see nl.tudelft.simulation.dsol.interpreter.Operation#getByteLength()
115 */
116 public int getByteLength()
117 {
118 return OPCODE_BYTE_LENGTH + this.byteLength;
119 }
120
121 /***
122 * @see nl.tudelft.simulation.dsol.interpreter.Operation#getOpcode()
123 */
124 public int getOpcode()
125 {
126 return TABLESWITCH.OP;
127 }
128 }