1 /*
2 * Copyright (C) 2008, Google Inc.
3 * Copyright (C) 2009, Johannes Schindelin <johannes.schindelin@gmx.de>
4 * and other copyright owners as documented in the project's IP log.
5 *
6 * This program and the accompanying materials are made available
7 * under the terms of the Eclipse Distribution License v1.0 which
8 * accompanies this distribution, is reproduced below, and is
9 * available at http://www.eclipse.org/org/documents/edl-v10.php
10 *
11 * All rights reserved.
12 *
13 * Redistribution and use in source and binary forms, with or
14 * without modification, are permitted provided that the following
15 * conditions are met:
16 *
17 * - Redistributions of source code must retain the above copyright
18 * notice, this list of conditions and the following disclaimer.
19 *
20 * - Redistributions in binary form must reproduce the above
21 * copyright notice, this list of conditions and the following
22 * disclaimer in the documentation and/or other materials provided
23 * with the distribution.
24 *
25 * - Neither the name of the Eclipse Foundation, Inc. nor the
26 * names of its contributors may be used to endorse or promote
27 * products derived from this software without specific prior
28 * written permission.
29 *
30 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
31 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
32 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
33 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
34 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
35 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
36 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
37 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
38 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
39 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
40 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
41 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
42 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
43 */
44
45 package org.eclipse.jgit.util;
46
47 /** A more efficient List<Integer> using a primitive integer array. */
48 public class IntList {
49 private int[] entries;
50
51 private int count;
52
53 /** Create an empty list with a default capacity. */
54 public IntList() {
55 this(10);
56 }
57
58 /**
59 * Create an empty list with the specified capacity.
60 *
61 * @param capacity
62 * number of entries the list can initially hold.
63 */
64 public IntList(final int capacity) {
65 entries = new int[capacity];
66 }
67
68 /** @return number of entries in this list */
69 public int size() {
70 return count;
71 }
72
73 /**
74 * @param i
75 * index to read, must be in the range [0, {@link #size()}).
76 * @return the number at the specified index
77 * @throws ArrayIndexOutOfBoundsException
78 * the index outside the valid range
79 */
80 public int get(final int i) {
81 if (count <= i)
82 throw new ArrayIndexOutOfBoundsException(i);
83 return entries[i];
84 }
85
86 /** Empty this list */
87 public void clear() {
88 count = 0;
89 }
90
91 /**
92 * Add an entry to the end of the list.
93 *
94 * @param n
95 * the number to add.
96 */
97 public void add(final int n) {
98 if (count == entries.length)
99 grow();
100 entries[count++] = n;
101 }
102
103 /**
104 * Assign an entry in the list.
105 *
106 * @param index
107 * index to set, must be in the range [0, {@link #size()}).
108 * @param n
109 * value to store at the position.
110 */
111 public void set(final int index, final int n) {
112 if (count < index)
113 throw new ArrayIndexOutOfBoundsException(index);
114 else if (count == index)
115 add(n);
116 else
117 entries[index] = n;
118 }
119
120 /**
121 * Pad the list with entries.
122 *
123 * @param toIndex
124 * index position to stop filling at. 0 inserts no filler. 1
125 * ensures the list has a size of 1, adding <code>val</code> if
126 * the list is currently empty.
127 * @param val
128 * value to insert into padded positions.
129 */
130 public void fillTo(int toIndex, final int val) {
131 while (count < toIndex)
132 add(val);
133 }
134
135 private void grow() {
136 final int[] n = new int[(entries.length + 16) * 3 / 2];
137 System.arraycopy(entries, 0, n, 0, count);
138 entries = n;
139 }
140
141 public String toString() {
142 final StringBuilder r = new StringBuilder();
143 r.append('[');
144 for (int i = 0; i < count; i++) {
145 if (i > 0)
146 r.append(", "); //$NON-NLS-1$
147 r.append(entries[i]);
148 }
149 r.append(']');
150 return r.toString();
151 }
152 }