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.Collections;
28import java.util.Iterator;
29import java.util.List;
30import java.util.Vector;
31
32import org.slf4j.Marker;
33
34/**
35 * A simple implementation of the {@link Marker} interface.
36 *
37 * @author Ceki Gülcü
38 * @author Joern Huxhorn
39 */
40public class BasicMarker implements Marker {
41
42    private static final long serialVersionUID = 1803952589649545191L;
43
44    private final String name;
45    private List<Marker> referenceList;
46
47    BasicMarker(String name) {
48        if (name == null) {
49            throw new IllegalArgumentException("A marker name cannot be null");
50        }
51        this.name = name;
52    }
53
54    public String getName() {
55        return name;
56    }
57
58    public synchronized void add(Marker reference) {
59        if (reference == null) {
60            throw new IllegalArgumentException("A null value cannot be added to a Marker as reference.");
61        }
62
63        // no point in adding the reference multiple times
64        if (this.contains(reference)) {
65            return;
66
67        } else if (reference.contains(this)) { // avoid recursion
68            // a potential reference should not its future "parent" as a reference
69            return;
70        } else {
71            // let's add the reference
72            if (referenceList == null) {
73                referenceList = new Vector<Marker>();
74            }
75            referenceList.add(reference);
76        }
77
78    }
79
80    public synchronized boolean hasReferences() {
81        return ((referenceList != null) && (referenceList.size() > 0));
82    }
83
84    public boolean hasChildren() {
85        return hasReferences();
86    }
87
88    public synchronized Iterator<Marker> iterator() {
89        if (referenceList != null) {
90            return referenceList.iterator();
91        } else {
92            List<Marker> emptyList = Collections.emptyList();
93            return emptyList.iterator();
94        }
95    }
96
97    public synchronized boolean remove(Marker referenceToRemove) {
98        if (referenceList == null) {
99            return false;
100        }
101
102        int size = referenceList.size();
103        for (int i = 0; i < size; i++) {
104            Marker m = (Marker) referenceList.get(i);
105            if (referenceToRemove.equals(m)) {
106                referenceList.remove(i);
107                return true;
108            }
109        }
110        return false;
111    }
112
113    public boolean contains(Marker other) {
114        if (other == null) {
115            throw new IllegalArgumentException("Other cannot be null");
116        }
117
118        if (this.equals(other)) {
119            return true;
120        }
121
122        if (hasReferences()) {
123            for (int i = 0; i < referenceList.size(); i++) {
124                Marker ref = (Marker) referenceList.get(i);
125                if (ref.contains(other)) {
126                    return true;
127                }
128            }
129        }
130        return false;
131    }
132
133    /**
134     * This method is mainly used with Expression Evaluators.
135     */
136    public boolean contains(String name) {
137        if (name == null) {
138            throw new IllegalArgumentException("Other cannot be null");
139        }
140
141        if (this.name.equals(name)) {
142            return true;
143        }
144
145        if (hasReferences()) {
146            for (int i = 0; i < referenceList.size(); i++) {
147                Marker ref = (Marker) referenceList.get(i);
148                if (ref.contains(name)) {
149                    return true;
150                }
151            }
152        }
153        return false;
154    }
155
156    private static String OPEN = "[ ";
157    private static String CLOSE = " ]";
158    private static String SEP = ", ";
159
160    public boolean equals(Object obj) {
161        if (this == obj)
162            return true;
163        if (obj == null)
164            return false;
165        if (!(obj instanceof Marker))
166            return false;
167
168        final Marker other = (Marker) obj;
169        return name.equals(other.getName());
170    }
171
172    public int hashCode() {
173        return name.hashCode();
174    }
175
176    public String toString() {
177        if (!this.hasReferences()) {
178            return this.getName();
179        }
180        Iterator<Marker> it = this.iterator();
181        Marker reference;
182        StringBuilder sb = new StringBuilder(this.getName());
183        sb.append(' ').append(OPEN);
184        while (it.hasNext()) {
185            reference = (Marker) it.next();
186            sb.append(reference.getName());
187            if (it.hasNext()) {
188                sb.append(SEP);
189            }
190        }
191        sb.append(CLOSE);
192
193        return sb.toString();
194    }
195}
196