1/*
2 * Javassist, a Java-bytecode translator toolkit.
3 * Copyright (C) 1999-2007 Shigeru Chiba, and others. All Rights Reserved.
4 *
5 * The contents of this file are subject to the Mozilla Public License Version
6 * 1.1 (the "License"); you may not use this file except in compliance with
7 * the License.  Alternatively, the contents of this file may be used under
8 * the terms of the GNU Lesser General Public License Version 2.1 or later.
9 *
10 * Software distributed under the License is distributed on an "AS IS" basis,
11 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
12 * for the specific language governing rights and limitations under the
13 * License.
14 */
15package javassist.bytecode.analysis;
16
17import java.util.NoSuchElementException;
18
19class IntQueue {
20    private static class Entry {
21        private IntQueue.Entry next;
22        private int value;
23        private Entry(int value) {
24            this.value = value;
25        }
26    }
27    private IntQueue.Entry head;
28
29    private IntQueue.Entry tail;
30
31    void add(int value) {
32        IntQueue.Entry entry = new Entry(value);
33        if (tail != null)
34            tail.next = entry;
35        tail = entry;
36
37        if (head == null)
38            head = entry;
39    }
40
41    boolean isEmpty() {
42        return head == null;
43    }
44
45    int take() {
46        if (head == null)
47            throw new NoSuchElementException();
48
49        int value = head.value;
50        head = head.next;
51        if (head == null)
52            tail = null;
53
54        return value;
55    }
56}