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1 | /******************************************************************************* |
2 | * Copyright (c) 2011-2012 Ericsson, Ecole Polytechnique de Montreal and others | |
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.Collection; | |
16 | import java.util.ListIterator; | |
17 | import java.util.Vector; | |
18 | ||
19 | /** | |
20 | * <b><u>StreamInputPacketIndex</u></b> | |
21 | * <p> | |
22 | * TODO Implement me. Please. | |
23 | */ | |
24 | public class StreamInputPacketIndex { | |
25 | ||
26 | // ------------------------------------------------------------------------ | |
27 | // Attributes | |
28 | // ------------------------------------------------------------------------ | |
29 | ||
30 | /** | |
31 | * Entries of the index. They are sorted by increasing begin timestamp. | |
32 | * index builder. | |
33 | */ | |
34 | private final Vector<StreamInputPacketIndexEntry> entries = new Vector<StreamInputPacketIndexEntry>(); | |
35 | ||
36 | // ------------------------------------------------------------------------ | |
37 | // Getters/Setters/Predicates | |
38 | // ------------------------------------------------------------------------ | |
39 | ||
40 | public Collection<StreamInputPacketIndexEntry> getEntries() { | |
41 | return this.entries; | |
42 | } | |
43 | ||
44 | public ListIterator<StreamInputPacketIndexEntry> listIterator() { | |
45 | return this.entries.listIterator(); | |
46 | } | |
47 | ||
48 | public ListIterator<StreamInputPacketIndexEntry> listIterator(int n) { | |
49 | return this.entries.listIterator(n); | |
50 | } | |
51 | ||
52 | // ------------------------------------------------------------------------ | |
53 | // Operations | |
54 | // ------------------------------------------------------------------------ | |
55 | ||
56 | /** | |
57 | * Adds an entry to the index. | |
58 | * | |
59 | * @param entry | |
60 | * The entry to add | |
61 | * @throws CTFReaderException | |
62 | */ | |
63 | public void addEntry(StreamInputPacketIndexEntry entry) | |
64 | throws CTFReaderException { | |
65 | assert (entry.packetSizeBits != 0); | |
66 | assert (entry.contentSizeBits != 0); | |
67 | ||
68 | if (entry.timestampBegin > entry.timestampEnd) { | |
69 | throw new CTFReaderException( | |
70 | "Packet begin timestamp is after end timestamp"); //$NON-NLS-1$ | |
71 | } | |
72 | ||
73 | if (!this.entries.isEmpty()) { | |
74 | if (entry.timestampBegin < this.entries.lastElement().timestampBegin) { | |
75 | throw new CTFReaderException( | |
76 | "Packets begin timestamp decreasing"); //$NON-NLS-1$ | |
77 | } | |
78 | } | |
79 | ||
80 | this.entries.add(entry); | |
81 | } | |
82 | ||
83 | /** | |
84 | * Given a timestamp, this methods returns the first PacketIndexEntry that | |
85 | * could include the timestamp, that is the last packet with a begin | |
86 | * timestamp smaller than the given timestamp. | |
87 | * | |
88 | * @param timestamp | |
89 | * The timestamp to look for. | |
90 | * @return The StreamInputPacketEntry that corresponds to the packet that | |
91 | * includes the given timestamp. | |
92 | */ | |
93 | public ListIterator<StreamInputPacketIndexEntry> search(final long timestamp) { | |
94 | /* | |
95 | * Start with min and max covering all the elements. | |
96 | */ | |
97 | int max = this.entries.size() - 1; | |
98 | int min = 0; | |
99 | ||
100 | int guessI; | |
101 | StreamInputPacketIndexEntry guessEntry = null; | |
102 | ||
103 | if (timestamp < 0) { | |
104 | throw new IllegalArgumentException("timestamp is negative"); //$NON-NLS-1$ | |
105 | } | |
106 | ||
107 | for (;;) { | |
108 | /* | |
109 | * Guess in the middle of min and max. The +1 is so that in case | |
110 | * (min + 1 == max), we choose the packet at the subscript "max" | |
111 | * instead of the one at "min". Otherwise, it would give an infinite | |
112 | * loop. | |
113 | */ | |
114 | guessI = (max + min + 1) / 2; | |
115 | guessEntry = this.entries.get(guessI); | |
116 | ||
117 | /* | |
118 | * If we reached the point where we focus on a single packet, our | |
119 | * search is done. | |
120 | */ | |
121 | if (min == max) { | |
122 | break; | |
123 | } | |
124 | ||
125 | if (timestamp < guessEntry.timestampBegin) { | |
126 | /* | |
127 | * If the timestamp if before the begin timestamp, we know that | |
128 | * the packet to return is before the guess. | |
129 | */ | |
130 | max = guessI - 1; | |
131 | } else if (timestamp >= guessEntry.timestampBegin) { | |
132 | /* | |
133 | * If the timestamp is after the begin timestamp, we know that | |
134 | * the packet to return is after the guess or is the guess. | |
135 | */ | |
136 | min = guessI; | |
137 | } | |
138 | } | |
139 | ||
140 | return this.entries.listIterator(guessI); | |
141 | } | |
142 | ||
143 | } |