1 /*
2 * Copyright (c) 2010, 2011, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23 package org.graalvm.compiler.core.common.util;
24
25 import java.util.Arrays;
26
27 /**
28 * An expandable and indexable list of {@code int}s.
29 *
30 * This class avoids the boxing/unboxing incurred by {@code ArrayList<Integer>}.
31 */
32 public final class IntList {
33
34 private int[] array;
35 private int size;
36
37 /**
38 * Creates an int list with a specified initial capacity.
39 *
40 * @param initialCapacity
41 */
42 public IntList(int initialCapacity) {
43 array = new int[initialCapacity];
44 }
45
46 /**
47 * Creates an int list with a specified initial array.
48 *
49 * @param array the initial array used for the list (no copy is made)
50 * @param initialSize the initial {@linkplain #size() size} of the list (must be less than or
51 * equal to {@code array.length}
52 */
53 public IntList(int[] array, int initialSize) {
54 assert initialSize <= array.length;
55 this.array = array;
56 this.size = initialSize;
57 }
58
59 /**
60 * Makes a new int list by copying a range from a given int list.
61 *
62 * @param other the list from which a range of values is to be copied into the new list
63 * @param startIndex the index in {@code other} at which to start copying
64 * @param length the number of values to copy from {@code other}
65 * @return a new int list whose {@linkplain #size() size} and capacity is {@code length}
66 */
67 public static IntList copy(IntList other, int startIndex, int length) {
68 return copy(other, startIndex, length, length);
69 }
70
71 /**
72 * Makes a new int list by copying a range from a given int list.
73 *
74 * @param other the list from which a range of values is to be copied into the new list
75 * @param startIndex the index in {@code other} at which to start copying
76 * @param length the number of values to copy from {@code other}
77 * @param initialCapacity the initial capacity of the new int list (must be greater or equal to
78 * {@code length})
79 * @return a new int list whose {@linkplain #size() size} is {@code length}
80 */
81 public static IntList copy(IntList other, int startIndex, int length, int initialCapacity) {
82 assert initialCapacity >= length : "initialCapacity < length";
83 int[] array = new int[initialCapacity];
84 System.arraycopy(other.array, startIndex, array, 0, length);
85 return new IntList(array, length);
86 }
87
88 public int size() {
89 return size;
90 }
91
92 /**
93 * Appends a value to the end of this list, increasing its {@linkplain #size() size} by 1.
94 *
95 * @param value the value to append
96 */
97 public void add(int value) {
98 if (size == array.length) {
99 int newSize = (size * 3) / 2 + 1;
100 array = Arrays.copyOf(array, newSize);
101 }
102 array[size++] = value;
103 }
104
105 /**
106 * Gets the value in this list at a given index.
107 *
108 * @param index the index of the element to return
109 * @throws IndexOutOfBoundsException if {@code index < 0 || index >= size()}
110 */
111 public int get(int index) {
112 if (index >= size) {
113 throw new IndexOutOfBoundsException("Index: " + index + ", Size: " + size);
114 }
115 return array[index];
116 }
117
118 /**
119 * Sets the size of this list to 0.
120 */
121 public void clear() {
122 size = 0;
123 }
124
125 /**
126 * Sets a value at a given index in this list.
127 *
128 * @param index the index of the element to update
129 * @param value the new value of the element
130 * @throws IndexOutOfBoundsException if {@code index < 0 || index >= size()}
131 */
132 public void set(int index, int value) {
133 if (index >= size) {
134 throw new IndexOutOfBoundsException("Index: " + index + ", Size: " + size);
135 }
136 array[index] = value;
137 }
138
139 /**
140 * Adjusts the {@linkplain #size() size} of this int list.
141 *
142 * If {@code newSize < size()}, the size is changed to {@code newSize}. If
143 * {@code newSize > size()}, sufficient 0 elements are {@linkplain #add(int) added} until
144 * {@code size() == newSize}.
145 *
146 * @param newSize the new size of this int list
147 */
148 public void setSize(int newSize) {
149 if (newSize < size) {
150 size = newSize;
151 } else if (newSize > size) {
152 array = Arrays.copyOf(array, newSize);
153 }
154 }
155
156 @Override
157 public String toString() {
158 if (array.length == size) {
159 return Arrays.toString(array);
160 }
161 return Arrays.toString(Arrays.copyOf(array, size));
162 }
163 }