1 /**
2 * Copyright (c) 2004-2011 QOS.ch
3 * All rights reserved.
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining
6 * a copy of this software and associated documentation files (the
7 * "Software"), to deal in the Software without restriction, including
8 * without limitation the rights to use, copy, modify, merge, publish,
9 * distribute, sublicense, and/or sell copies of the Software, and to
10 * permit persons to whom the Software is furnished to do so, subject to
11 * the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be
14 * included in all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
17 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
18 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
19 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
20 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
21 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
22 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
23 *
24 */
25 package org.slf4j;
26
27 public class NDC {
28 public final static String PREFIX = "NDC";
29
30 private static int size() {
31 int i = 0;
32 while (true) {
33 String val = MDC.get(PREFIX + i);
34 if (val != null) {
35 i++;
36 } else {
37 break;
38 }
39 }
40 return i;
41 }
42
43 public static void push(String val) {
44 int next = size();
45 MDC.put(PREFIX + next, val);
46 }
47
48 public static String pop() {
49 int next = size();
50 if (next == 0) {
51 return "";
52 }
53 int last = next - 1;
54 String key = PREFIX + last;
55 String val = MDC.get(key);
56 MDC.remove(key);
57 return val;
58 }
59
60 }