001/**
002 * Copyright (c) 2004-2011 QOS.ch
003 * All rights reserved.
004 *
005 * Permission is hereby granted, free  of charge, to any person obtaining
006 * a  copy  of this  software  and  associated  documentation files  (the
007 * "Software"), to  deal in  the Software without  restriction, including
008 * without limitation  the rights to  use, copy, modify,  merge, publish,
009 * distribute,  sublicense, and/or sell  copies of  the Software,  and to
010 * permit persons to whom the Software  is furnished to do so, subject to
011 * the following conditions:
012 *
013 * The  above  copyright  notice  and  this permission  notice  shall  be
014 * included in all copies or substantial portions of the Software.
015 *
016 * THE  SOFTWARE IS  PROVIDED  "AS  IS", WITHOUT  WARRANTY  OF ANY  KIND,
017 * EXPRESS OR  IMPLIED, INCLUDING  BUT NOT LIMITED  TO THE  WARRANTIES OF
018 * MERCHANTABILITY,    FITNESS    FOR    A   PARTICULAR    PURPOSE    AND
019 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
020 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
021 * OF CONTRACT, TORT OR OTHERWISE,  ARISING FROM, OUT OF OR IN CONNECTION
022 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
023 *
024 */
025package org.slf4j.helpers;
026
027import java.util.concurrent.ConcurrentHashMap;
028import java.util.concurrent.ConcurrentMap;
029
030import org.slf4j.IMarkerFactory;
031import org.slf4j.Marker;
032
033/**
034 * An almost trivial implementation of the {@link IMarkerFactory}
035 * interface which creates {@link BasicMarker} instances.
036 * 
037 * <p>Simple logging systems can conform to the SLF4J API by binding
038 * {@link org.slf4j.MarkerFactory} with an instance of this class.
039 *
040 * @author Ceki G&uuml;lc&uuml;
041 */
042public class BasicMarkerFactory implements IMarkerFactory {
043
044    private final ConcurrentMap<String, Marker> markerMap = new ConcurrentHashMap<>();
045
046    /**
047     * Regular users should <em>not</em> create
048     * <code>BasicMarkerFactory</code> instances. <code>Marker</code>
049     * instances can be obtained using the static {@link
050     * org.slf4j.MarkerFactory#getMarker} method.
051     */
052    public BasicMarkerFactory() {
053    }
054
055    /**
056     * Manufacture a {@link BasicMarker} instance by name. If the instance has been 
057     * created earlier, return the previously created instance. 
058     * 
059     * @param name the name of the marker to be created
060     * @return a Marker instance
061     */
062    public Marker getMarker(String name) {
063        if (name == null) {
064            throw new IllegalArgumentException("Marker name cannot be null");
065        }
066
067        Marker marker = markerMap.get(name);
068        if (marker == null) {
069            marker = new BasicMarker(name);
070            Marker oldMarker = markerMap.putIfAbsent(name, marker);
071            if (oldMarker != null) {
072                marker = oldMarker;
073            }
074        }
075        return marker;
076    }
077
078    /**
079     * Does the name marked already exist?
080     */
081    public boolean exists(String name) {
082        if (name == null) {
083            return false;
084        }
085        return markerMap.containsKey(name);
086    }
087
088    public boolean detachMarker(String name) {
089        if (name == null) {
090            return false;
091        }
092        return (markerMap.remove(name) != null);
093    }
094
095    public Marker getDetachedMarker(String name) {
096        return new BasicMarker(name);
097    }
098
099}