1<?php
2/**
3 * Licensed to the Apache Software Foundation (ASF) under one or more
4 * contributor license agreements. See the NOTICE file distributed with
5 * this work for additional information regarding copyright ownership.
6 * The ASF licenses this file to You under the Apache License, Version 2.0
7 * (the "License"); you may not use this file except in compliance with
8 * the License. You may obtain a copy of the License at
9 *
10 *	   http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing, software
13 * distributed under the License is distributed on an "AS IS" BASIS,
14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 * See the License for the specific language governing permissions and
16 * limitations under the License.
17 *
18 * @package log4php
19 */
20
21/**
22 * This is the global repository of user mappings
23 */
24$GLOBALS['log4php.LoggerMDC.ht'] = array();
25
26/**
27 * The LoggerMDC class provides <i>mapped diagnostic contexts</i>.
28 *
29 * <p>A <i>Mapped Diagnostic Context</i>, or
30 * MDC in short, is an instrument for distinguishing interleaved log
31 * output from different sources. Log output is typically interleaved
32 * when a server handles multiple clients near-simultaneously.
33 *
34 * <p>This class is similar to the {@link LoggerNDC} class except that
35 * it is based on a map instead of a stack.
36 *
37 * <p><b>The MDC is managed on a per thread basis</b>.
38 *
39 * <p>Example:
40 *
41 * {@example ../../examples/php/mdc.php 19}<br>
42 *
43 * With the properties file:
44 *
45 * {@example ../../examples/resources/mdc.properties 18}<br>
46 *
47 * Will result in the following (notice the username "knut" in the output):
48 *
49 * <pre>
50 * 2009-09-13 18:48:28 DEBUG root knut: Testing MDC in src/examples/php/mdc.php at 23
51 * </pre>
52 *
53 * @version $Revision: 883114 $
54 * @since 0.3
55 * @package log4php
56 */
57class LoggerMDC {
58	/**
59	 * Put a context value as identified with the key parameter into the current thread's
60	 *	context map.
61	 *
62	 * <p>If the current thread does not have a context map it is
63	 *	created as a side effect.</p>
64	 *
65	 * <p>Note that you cannot put more than {@link self::HT_SIZE} keys.</p>
66	 *
67	 * @param string $key the key
68	 * @param string $value the value
69	 * @static
70	 */
71	public static function put($key, $value) {
72		$GLOBALS['log4php.LoggerMDC.ht'][$key] = $value;
73	}
74
75	/**
76	 * Get the context identified by the key parameter.
77	 *
78	 * <p>You can use special key identifiers to map values in
79	 * PHP $_SERVER and $_ENV vars. Just put a 'server.' or 'env.'
80	 * followed by the var name you want to refer.</p>
81	 *
82	 * <p>This method has no side effects.</p>
83	 *
84	 * @param string $key
85	 * @return string
86	 * @static
87	 */
88	public static function get($key) {
89		if(!empty($key)) {
90			if(strpos($key, 'server.') === 0) {
91				$varName = substr($key, 7);
92				return @$_SERVER[$varName];
93			} else if(strpos($key, 'env.') === 0) {
94				$varName = substr($key, 4);
95				return @$_ENV[$varName];
96			} else if (isset($GLOBALS['log4php.LoggerMDC.ht'][$key])) {
97				return $GLOBALS['log4php.LoggerMDC.ht'][$key];
98			}
99		}
100		return '';
101	}
102
103	/**
104	 * Remove the the context identified by the key parameter.
105	 *
106	 * It only affects user mappings.
107	 *
108	 * @param string $key
109	 * @return string
110	 * @static
111	 */
112	public static function remove($key) {
113		unset($GLOBALS['log4php.LoggerMDC.ht'][$key]);
114	}
115
116}
117