1 /* 2 * Copyright (c) 2015, 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 gc.g1.plab.lib; 24 25 /** 26 * The Storage is used for storing reachable objects. 27 * Class will store not more than capacity, which can be set during creation. 28 * If we exceed capacity, object will be stored at existing entries. 29 * So, if capacity=1, all previously added objects will be unreachable. 30 */ 31 public class Storage { 32 33 private int capacity; 34 35 private Object[] array; 36 private int index; 37 38 /** 39 * Create Storage object with defined capacity 40 * 41 * @param capacity 42 */ 43 public Storage(int capacity) { 44 if (capacity <= 0) { 45 throw new IllegalArgumentException("Items number should be greater than 0."); 46 } 47 this.capacity = capacity; 48 index = 0; 49 array = new Object[this.capacity]; 50 } 51 52 /** 53 * Store object into Storage. 54 * 55 * @param o - Object to store 56 */ 57 public void store(Object o) { 58 if (array == null) { 59 throw new RuntimeException("Capacity should be set before storing"); 60 } 61 array[index % capacity] = o; 62 ++index; 63 } 64 65 /** 66 * Clear all stored objects. 67 */ 68 public void clear() { 69 array = null; 70 } 71 }