1/* 2 * Copyright (c) 1999, 2013, 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. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26package com.sun.tools.javac.util; 27 28import java.lang.reflect.Array; 29 30/** <p><b>This is NOT part of any supported API. 31 * If you write code that depends on this, you do so at your own risk. 32 * This code and its internal interfaces are subject to change or 33 * deletion without notice.</b> 34 */ 35public class ArrayUtils { 36 37 private static int calculateNewLength(int currentLength, int maxIndex) { 38 while (currentLength < maxIndex + 1) 39 currentLength = currentLength * 2; 40 return currentLength; 41 } 42 43 public static <T> T[] ensureCapacity(T[] array, int maxIndex) { 44 if (maxIndex < array.length) { 45 return array; 46 } else { 47 int newLength = calculateNewLength(array.length, maxIndex); 48 @SuppressWarnings("unchecked") 49 T[] result = (T[]) Array.newInstance(array.getClass().getComponentType(), newLength); 50 System.arraycopy(array, 0, result, 0, array.length); 51 return result; 52 } 53 } 54 55 public static byte[] ensureCapacity(byte[] array, int maxIndex) { 56 if (maxIndex < array.length) { 57 return array; 58 } else { 59 int newLength = calculateNewLength(array.length, maxIndex); 60 byte[] result = new byte[newLength]; 61 System.arraycopy(array, 0, result, 0, array.length); 62 return result; 63 } 64 } 65 66 public static char[] ensureCapacity(char[] array, int maxIndex) { 67 if (maxIndex < array.length) { 68 return array; 69 } else { 70 int newLength = calculateNewLength(array.length, maxIndex); 71 char[] result = new char[newLength]; 72 System.arraycopy(array, 0, result, 0, array.length); 73 return result; 74 } 75 } 76 77 public static int[] ensureCapacity(int[] array, int maxIndex) { 78 if (maxIndex < array.length) { 79 return array; 80 } else { 81 int newLength = calculateNewLength(array.length, maxIndex); 82 int[] result = new int[newLength]; 83 System.arraycopy(array, 0, result, 0, array.length); 84 return result; 85 } 86 } 87 88} 89