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1   /*
2    *  Licensed to the Apache Software Foundation (ASF) under one
3    *  or more contributor license agreements.  See the NOTICE file
4    *  distributed with this work for additional information
5    *  regarding copyright ownership.  The ASF licenses this file
6    *  to you under the Apache License, Version 2.0 (the
7    *  "License"); you may not use this file except in compliance
8    *  with 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,
13   *  software distributed under the License is distributed on an
14   *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15   *  KIND, either express or implied.  See the License for the
16   *  specific language governing permissions and limitations
17   *  under the License.
18   *
19   */
20  package org.apache.mina.core.session;
21  
22  import java.util.HashMap;
23  import java.util.HashSet;
24  import java.util.Queue;
25  import java.util.Set;
26  import java.util.concurrent.ConcurrentHashMap;
27  import java.util.concurrent.ConcurrentLinkedQueue;
28  
29  import org.apache.mina.core.write.WriteRequest;
30  import org.apache.mina.core.write.WriteRequestQueue;
31  
32  /**
33   * The default {@link IoSessionDataStructureFactory} implementation
34   * that creates a new {@link HashMap}-based {@link IoSessionAttributeMap}
35   * instance and a new synchronized {@link ConcurrentLinkedQueue} instance per
36   * {@link IoSession}.
37   * 
38   * @author <a href="http://mina.apache.org">Apache MINA Project</a>
39   */
40  public class DefaultIoSessionDataStructureFactory implements IoSessionDataStructureFactory {
41  
42      public IoSessionAttributeMap getAttributeMap(IoSession session) throws Exception {
43          return new DefaultIoSessionAttributeMap();
44      }
45  
46      public WriteRequestQueue getWriteRequestQueue(IoSession session) throws Exception {
47          return new DefaultWriteRequestQueue();
48      }
49  
50      private static class DefaultIoSessionAttributeMap implements IoSessionAttributeMap {
51          private final ConcurrentHashMap<Object, Object> attributes = new ConcurrentHashMap<Object, Object>(4);
52  
53          /**
54           * Default constructor
55           */
56          public DefaultIoSessionAttributeMap() {
57              super();
58          }
59  
60          /**
61           * {@inheritDoc}
62           */
63          public Object getAttribute(IoSession session, Object key, Object defaultValue) {
64              if (key == null) {
65                  throw new IllegalArgumentException("key");
66              }
67  
68              if (defaultValue == null) {
69                  return attributes.get(key);
70              }
71  
72              Object object = attributes.putIfAbsent(key, defaultValue);
73  
74              if (object == null) {
75                  return defaultValue;
76              } else {
77                  return object;
78              }
79          }
80  
81          /**
82           * {@inheritDoc}
83           */
84          public Object setAttribute(IoSession session, Object key, Object value) {
85              if (key == null) {
86                  throw new IllegalArgumentException("key");
87              }
88  
89              if (value == null) {
90                  return attributes.remove(key);
91              }
92  
93              return attributes.put(key, value);
94          }
95  
96          /**
97           * {@inheritDoc}
98           */
99          public Object setAttributeIfAbsent(IoSession session, Object key, Object value) {
100             if (key == null) {
101                 throw new IllegalArgumentException("key");
102             }
103 
104             if (value == null) {
105                 return null;
106             }
107 
108             return attributes.putIfAbsent(key, value);
109         }
110 
111         /**
112          * {@inheritDoc}
113          */
114         public Object removeAttribute(IoSession session, Object key) {
115             if (key == null) {
116                 throw new IllegalArgumentException("key");
117             }
118 
119             return attributes.remove(key);
120         }
121 
122         /**
123          * {@inheritDoc}
124          */
125         public boolean removeAttribute(IoSession session, Object key, Object value) {
126             if (key == null) {
127                 throw new IllegalArgumentException("key");
128             }
129 
130             if (value == null) {
131                 return false;
132             }
133 
134             try {
135                 return attributes.remove(key, value);
136             } catch (NullPointerException e) {
137                 return false;
138             }
139         }
140 
141         /**
142          * {@inheritDoc}
143          */
144         public boolean replaceAttribute(IoSession session, Object key, Object oldValue, Object newValue) {
145             try {
146                 return attributes.replace(key, oldValue, newValue);
147             } catch (NullPointerException e) {
148             }
149 
150             return false;
151         }
152 
153         /**
154          * {@inheritDoc}
155          */
156         public boolean containsAttribute(IoSession session, Object key) {
157             return attributes.containsKey(key);
158         }
159 
160         /**
161          * {@inheritDoc}
162          */
163         public Set<Object> getAttributeKeys(IoSession session) {
164             synchronized (attributes) {
165                 return new HashSet<Object>(attributes.keySet());
166             }
167         }
168 
169         /**
170          * {@inheritDoc}
171          */
172         public void dispose(IoSession session) throws Exception {
173             // Do nothing
174         }
175     }
176 
177     private static class DefaultWriteRequestQueue implements WriteRequestQueue {
178         /** A queue to store incoming write requests */
179         private final Queue<WriteRequest> q = new ConcurrentLinkedQueue<WriteRequest>();
180 
181         /**
182          * Default constructor
183          */
184         public DefaultWriteRequestQueue() {
185         }
186 
187         /**
188          * {@inheritDoc}
189          */
190         public void dispose(IoSession session) {
191             // Do nothing
192         }
193 
194         /**
195          * {@inheritDoc}
196          */
197         public void clear(IoSession session) {
198             q.clear();
199         }
200 
201         /**
202          * {@inheritDoc}
203          */
204         public boolean isEmpty(IoSession session) {
205             return q.isEmpty();
206         }
207 
208         /**
209          * {@inheritDoc}
210          */
211         public void offer(IoSession session, WriteRequest writeRequest) {
212             q.offer(writeRequest);
213         }
214 
215         /**
216          * {@inheritDoc}
217          */
218         public WriteRequest poll(IoSession session) {
219             WriteRequest answer = q.poll();
220 
221             if (answer == AbstractIoSession.CLOSE_REQUEST) {
222                 session.closeNow();
223                 dispose(session);
224                 answer = null;
225             }
226 
227             return answer;
228         }
229 
230         @Override
231         public String toString() {
232             return q.toString();
233         }
234 
235         /**
236          * {@inheritDoc}
237          */
238         public int size() {
239             return q.size();
240         }
241     }
242 }