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866e5b51 | 1 | /******************************************************************************* |
60ae41e1 | 2 | * Copyright (c) 2011, 2013 Ericsson, Ecole Polytechnique de Montreal and others |
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3 | * |
4 | * All rights reserved. This program and the accompanying materials are made | |
5 | * available under the terms of the Eclipse Public License v1.0 which | |
6 | * accompanies this distribution, and is available at | |
7 | * http://www.eclipse.org/legal/epl-v10.html | |
8 | * | |
9 | * Contributors: Matthew Khouzam - Initial API and implementation | |
10 | * Contributors: Simon Marchi - Initial API and implementation | |
11 | *******************************************************************************/ | |
12 | ||
13 | package org.eclipse.linuxtools.ctf.core.trace; | |
14 | ||
15 | import java.util.UUID; | |
16 | ||
17 | /** | |
866e5b51 | 18 | * Various utilities. |
0594c61c | 19 | * |
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20 | * @version 1.0 |
21 | * @author Matthew Khouzam | |
22 | * @author Simon Marchi | |
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23 | */ |
24 | public class Utils { | |
25 | ||
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26 | private Utils() {} |
27 | ||
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28 | // ------------------------------------------------------------------------ |
29 | // Constants | |
30 | // ------------------------------------------------------------------------ | |
31 | ||
32 | /** | |
9ac2eb62 | 33 | * CTF magic number. (sort of looks like CTF CTF CT) |
866e5b51 | 34 | */ |
0594c61c | 35 | public static final int CTF_MAGIC = 0xC1FC1FC1; |
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36 | |
37 | /** | |
9ac2eb62 | 38 | * TSDL magic number. (sort of looks like TSDL LSDT) |
866e5b51 | 39 | */ |
0594c61c | 40 | public static final int TSDL_MAGIC = 0x75D11D57; |
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41 | |
42 | /** | |
43 | * TSDL magic number length in bytes. | |
44 | */ | |
0594c61c | 45 | public static final int TSDL_MAGIC_LEN = 4; |
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46 | |
47 | /** | |
48 | * Directory separator on the current platform. | |
49 | */ | |
0594c61c | 50 | public static final String SEPARATOR = System.getProperty("file.separator"); //$NON-NLS-1$ |
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51 | |
52 | /** | |
53 | * Length in bytes of a UUID value. | |
54 | */ | |
0594c61c | 55 | public static final int UUID_LEN = 16; |
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56 | |
57 | // ------------------------------------------------------------------------ | |
58 | // Operations | |
59 | // ------------------------------------------------------------------------ | |
60 | ||
61 | /** | |
1c8799d5 | 62 | * Performs an unsigned long comparison on two unsigned long numbers. |
866e5b51 | 63 | * |
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64 | * @note As Java does not support unsigned types and arithmetic, parameters |
65 | * are received encoded as a signed long (two-complement) but the | |
66 | * operation is an unsigned comparator. | |
67 | * | |
68 | * @param left | |
69 | * Left operand of the comparator. | |
70 | * @param right | |
71 | * Right operand of the comparator. | |
72 | * @return -1 if left < right, 1 if left > right, 0 if left == right. | |
866e5b51 | 73 | */ |
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74 | public static int unsignedCompare(long left, long right) { |
75 | /* | |
76 | * This method assumes that the arithmetic overflow on signed | |
77 | * integer wrap on a circular domain (modulo arithmetic in | |
78 | * two-complement), which is the defined behavior in Java. | |
79 | * | |
80 | * This idea is to rotate the domain by the length of the negative | |
81 | * space, and then use the signed operator. | |
82 | */ | |
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83 | final long a = left + Long.MIN_VALUE; |
84 | final long b = right + Long.MIN_VALUE; | |
85 | if (a < b) { | |
86 | return -1; | |
87 | } else if (a > b) { | |
88 | return 1; | |
89 | } | |
90 | return 0; | |
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91 | } |
92 | ||
93 | /** | |
94 | * Creates a UUID object from an array of 16 bytes. | |
95 | * | |
96 | * @param bytes | |
97 | * Array of 16 bytes. | |
98 | * @return A UUID object. | |
99 | */ | |
100 | public static UUID makeUUID(byte bytes[]) { | |
101 | long high = 0; | |
102 | long low = 0; | |
103 | ||
104 | assert (bytes.length == Utils.UUID_LEN); | |
105 | ||
106 | for (int i = 0; i < 8; i++) { | |
107 | low = (low << 8) | (bytes[i + 8] & 0xFF); | |
108 | high = (high << 8) | (bytes[i] & 0xFF); | |
109 | } | |
110 | ||
111 | UUID uuid = new UUID(high, low); | |
112 | ||
113 | return uuid; | |
114 | } | |
115 | ||
116 | } |