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 */
25package org.slf4j.helpers;
26
27import java.util.concurrent.ConcurrentHashMap;
28import java.util.concurrent.ConcurrentMap;
29
30import org.slf4j.IMarkerFactory;
31import org.slf4j.Marker;
32
33/**
34 * An almost trivial implementation of the {@link IMarkerFactory}
35 * interface which creates {@link BasicMarker} instances.
36 *
37 * <p>Simple logging systems can conform to the SLF4J API by binding
38 * {@link org.slf4j.MarkerFactory} with an instance of this class.
39 *
40 * @author Ceki G&uuml;lc&uuml;
41 */
42public class BasicMarkerFactory implements IMarkerFactory {
43
44    private final ConcurrentMap<String, Marker> markerMap = new ConcurrentHashMap<String, Marker>();
45
46    /**
47     * Regular users should <em>not</em> create
48     * <code>BasicMarkerFactory</code> instances. <code>Marker</code>
49     * instances can be obtained using the static {@link
50     * org.slf4j.MarkerFactory#getMarker} method.
51     */
52    public BasicMarkerFactory() {
53    }
54
55    /**
56     * Manufacture a {@link BasicMarker} instance by name. If the instance has been
57     * created earlier, return the previously created instance.
58     *
59     * @param name the name of the marker to be created
60     * @return a Marker instance
61     */
62    public Marker getMarker(String name) {
63        if (name == null) {
64            throw new IllegalArgumentException("Marker name cannot be null");
65        }
66
67        Marker marker = markerMap.get(name);
68        if (marker == null) {
69            marker = new BasicMarker(name);
70            Marker oldMarker = markerMap.putIfAbsent(name, marker);
71            if (oldMarker != null) {
72                marker = oldMarker;
73            }
74        }
75        return marker;
76    }
77
78    /**
79     * Does the name marked already exist?
80     */
81    public boolean exists(String name) {
82        if (name == null) {
83            return false;
84        }
85        return markerMap.containsKey(name);
86    }
87
88    public boolean detachMarker(String name) {
89        if (name == null) {
90            return false;
91        }
92        return (markerMap.remove(name) != null);
93    }
94
95    public Marker getDetachedMarker(String name) {
96        return new BasicMarker(name);
97    }
98
99}
100