| /* |
| * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package jdk.nashorn.internal; |
| |
| /** |
| * Small helper class for fast int deques |
| */ |
| public class IntDeque { |
| private int[] deque = new int[16]; |
| private int nextFree = 0; |
| |
| /** |
| * Push an int value |
| * @param value value |
| */ |
| public void push(final int value) { |
| if (nextFree == deque.length) { |
| final int[] newDeque = new int[nextFree * 2]; |
| System.arraycopy(deque, 0, newDeque, 0, nextFree); |
| deque = newDeque; |
| } |
| deque[nextFree++] = value; |
| } |
| |
| /** |
| * Pop an int value |
| * @return value |
| */ |
| public int pop() { |
| return deque[--nextFree]; |
| } |
| |
| /** |
| * Peek |
| * @return top value |
| */ |
| public int peek() { |
| return deque[nextFree - 1]; |
| } |
| |
| /** |
| * Get the value of the top element and increment it. |
| * @return top value |
| */ |
| public int getAndIncrement() { |
| return deque[nextFree - 1]++; |
| } |
| |
| /** |
| * Decrement the value of the top element and return it. |
| * @return decremented top value |
| */ |
| public int decrementAndGet() { |
| return --deque[nextFree - 1]; |
| } |
| |
| /** |
| * Check if deque is empty |
| * @return true if empty |
| */ |
| public boolean isEmpty() { |
| return nextFree == 0; |
| } |
| } |