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 /**
48 * A more efficient List<Integer> using a primitive integer array.
49 */
50 public class IntList {
51 private int[] entries;
52
53 private int count;
54
55 /**
56 * Create an empty list with a default capacity.
57 */
58 public IntList() {
59 this(10);
60 }
61
62 /**
63 * Create an empty list with the specified capacity.
64 *
65 * @param capacity
66 * number of entries the list can initially hold.
67 */
68 public IntList(int capacity) {
69 entries = new int[capacity];
70 }
71
72 /**
73 * Get number of entries in this list.
74 *
75 * @return number of entries in this list.
76 */
77 public int size() {
78 return count;
79 }
80
81 /**
82 * Check if an entry appears in this collection.
83 *
84 * @param value
85 * the value to search for.
86 * @return true of {@code value} appears in this list.
87 * @since 4.9
88 */
89 public boolean contains(int value) {
90 for (int i = 0; i < count; i++)
91 if (entries[i] == value)
92 return true;
93 return false;
94 }
95
96 /**
97 * Get the value at the specified index
98 *
99 * @param i
100 * index to read, must be in the range [0, {@link #size()}).
101 * @return the number at the specified index
102 * @throws java.lang.ArrayIndexOutOfBoundsException
103 * the index outside the valid range
104 */
105 public int get(int i) {
106 if (count <= i)
107 throw new ArrayIndexOutOfBoundsException(i);
108 return entries[i];
109 }
110
111 /**
112 * Empty this list
113 */
114 public void clear() {
115 count = 0;
116 }
117
118 /**
119 * Add an entry to the end of the list.
120 *
121 * @param n
122 * the number to add.
123 */
124 public void add(int n) {
125 if (count == entries.length)
126 grow();
127 entries[count++] = n;
128 }
129
130 /**
131 * Assign an entry in the list.
132 *
133 * @param index
134 * index to set, must be in the range [0, {@link #size()}).
135 * @param n
136 * value to store at the position.
137 */
138 public void set(int index, int n) {
139 if (count < index)
140 throw new ArrayIndexOutOfBoundsException(index);
141 else if (count == index)
142 add(n);
143 else
144 entries[index] = n;
145 }
146
147 /**
148 * Pad the list with entries.
149 *
150 * @param toIndex
151 * index position to stop filling at. 0 inserts no filler. 1
152 * ensures the list has a size of 1, adding <code>val</code> if
153 * the list is currently empty.
154 * @param val
155 * value to insert into padded positions.
156 */
157 public void fillTo(int toIndex, int val) {
158 while (count < toIndex)
159 add(val);
160 }
161
162 private void grow() {
163 final int[] n = new int[(entries.length + 16) * 3 / 2];
164 System.arraycopy(entries, 0, n, 0, count);
165 entries = n;
166 }
167
168 /** {@inheritDoc} */
169 @Override
170 public String toString() {
171 final StringBuilder r = new StringBuilder();
172 r.append('[');
173 for (int i = 0; i < count; i++) {
174 if (i > 0)
175 r.append(", "); //$NON-NLS-1$
176 r.append(entries[i]);
177 }
178 r.append(']');
179 return r.toString();
180 }
181 }