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comparison src/org/tmatesoft/hg/internal/IntVector.java @ 288:b11f6a08f748

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Avoid boxing int values and list resizes on revlog read
author Artem Tikhomirov <tikhomirov.artem@gmail.com>
date Sat, 10 Sep 2011 00:18:39 +0200
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children a674b8590362
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287:ed6b74a58c66 288:b11f6a08f748
1 /*
2 * Copyright (c) 2011 TMate Software Ltd
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; version 2 of the License.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 * For information on how to redistribute this software under
14 * the terms of a license other than GNU General Public License
15 * contact TMate Software at support@hg4j.com
16 */
17 package org.tmatesoft.hg.internal;
18
19 /**
20 *
21 * @author Artem Tikhomirov
22 * @author TMate Software Ltd.
23 */
24 class IntVector {
25
26 private int[] data;
27 private final int increment;
28 private int count;
29
30
31 public IntVector() {
32 this(16, -1);
33 }
34
35 // increment == -1: grow by power of two.
36 // increment == 0: no resize (Exception will be thrown on attempt to add past capacity)
37 public IntVector(int initialCapacity, int increment) {
38 data = new int[initialCapacity];
39 this.increment = increment;
40 }
41
42 public void add(int v) {
43 if (count == data.length) {
44 grow();
45 }
46 data[count++] = v;
47 }
48
49 public int get(int i) {
50 if (i < 0 || i >= count) {
51 throw new IndexOutOfBoundsException(String.format("Index: %d, size: %d", i, count));
52 }
53 return data[i];
54 }
55
56 public int size() {
57 return count;
58 }
59
60 public int[] toArray() {
61 int[] rv = new int[count];
62 System.arraycopy(data, 0, rv, 0, count);
63 return rv;
64 }
65
66 /**
67 * Use only when this instance won't be used any longer
68 */
69 @Experimental
70 int[] toArray(boolean internalIfSizeMatchCapacity) {
71 if (count == data.length) {
72 return data;
73 }
74 return toArray();
75 }
76
77 private void grow() {
78 if (increment == 0) {
79 // throw specific exception right away
80 return;
81 }
82 int newCapacity = increment < 0 ? data.length << 1 : data.length + increment;
83 assert newCapacity > 0 && newCapacity != data.length : newCapacity;
84 int[] newData = new int[newCapacity];
85 System.arraycopy(data, 0, newData, 0, count);
86 data = newData;
87 }
88 }