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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.filter.reqres;
21  
22  import java.util.NoSuchElementException;
23  import java.util.concurrent.BlockingQueue;
24  import java.util.concurrent.LinkedBlockingQueue;
25  import java.util.concurrent.ScheduledFuture;
26  import java.util.concurrent.TimeUnit;
27  
28  /**
29   * TODO Add documentation
30   * 
31   * @author <a href="http://mina.apache.org">Apache MINA Project</a>
32   */
33  public class Request {
34      private final Object id;
35  
36      private final Object message;
37  
38      private final long timeoutMillis;
39  
40      private volatile Runnable timeoutTask;
41  
42      private volatile ScheduledFuture<?> timeoutFuture;
43  
44      private final BlockingQueue<Object> responses;
45  
46      private volatile boolean endOfResponses;
47  
48      public Request(Object id, Object message, long timeoutMillis) {
49          this(id, message, true, timeoutMillis);
50      }
51  
52      public Request(Object id, Object message, boolean useResponseQueue,
53                     long timeoutMillis) {
54          this(id, message, useResponseQueue, timeoutMillis,
55                  TimeUnit.MILLISECONDS);
56      }
57  
58      public Request(Object id, Object message, long timeout, TimeUnit unit) {
59          this(id, message, true, timeout, unit);
60      }
61  
62      public Request(Object id, Object message, boolean useResponseQueue,
63                     long timeout, TimeUnit unit) {
64          if (id == null) {
65              throw new NullPointerException("id");
66          }
67          if (message == null) {
68              throw new NullPointerException("message");
69          }
70          if (timeout < 0) {
71              throw new IllegalArgumentException("timeout: " + timeout
72                      + " (expected: 0+)");
73          } else if (timeout == 0) {
74              timeout = Long.MAX_VALUE;
75          }
76  
77          if (unit == null) {
78              throw new NullPointerException("unit");
79          }
80  
81          this.id = id;
82          this.message = message;
83          this.responses = useResponseQueue ? new LinkedBlockingQueue<Object>() : null;
84          this.timeoutMillis = unit.toMillis(timeout);
85      }
86  
87      public Object getId() {
88          return id;
89      }
90  
91      public Object getMessage() {
92          return message;
93      }
94  
95      public long getTimeoutMillis() {
96          return timeoutMillis;
97      }
98  
99      public boolean isUseResponseQueue() {
100         return responses != null;
101     }
102 
103     public boolean hasResponse() {
104         checkUseResponseQueue();
105         return !responses.isEmpty();
106     }
107 
108     public Response awaitResponse() throws RequestTimeoutException,
109             InterruptedException {
110         checkUseResponseQueue();
111         chechEndOfResponses();
112         return convertToResponse(responses.take());
113     }
114 
115     public Response awaitResponse(long timeout, TimeUnit unit)
116             throws RequestTimeoutException, InterruptedException {
117         checkUseResponseQueue();
118         chechEndOfResponses();
119         return convertToResponse(responses.poll(timeout, unit));
120     }
121 
122     private Response convertToResponse(Object o) {
123         if (o instanceof Response) {
124             return (Response) o;
125         }
126 
127         if (o == null) {
128             return null;
129         }
130 
131         throw (RequestTimeoutException) o;
132     }
133 
134     public Response awaitResponseUninterruptibly()
135             throws RequestTimeoutException {
136         for (; ;) {
137             try {
138                 return awaitResponse();
139             } catch (InterruptedException e) {
140                 // Do nothing
141             }
142         }
143     }
144 
145     private void chechEndOfResponses() {
146         if (responses != null && endOfResponses && responses.isEmpty()) {
147             throw new NoSuchElementException(
148                     "All responses has been retrieved already.");
149         }
150     }
151 
152     private void checkUseResponseQueue() {
153         if (responses == null) {
154             throw new UnsupportedOperationException(
155                     "Response queue is not available; useResponseQueue is false.");
156         }
157     }
158 
159     void signal(Response response) {
160         signal0(response);
161         if (response.getType() != ResponseType.PARTIAL) {
162             endOfResponses = true;
163         }
164     }
165 
166     void signal(RequestTimeoutException e) {
167         signal0(e);
168         endOfResponses = true;
169     }
170 
171     private void signal0(Object answer) {
172         if (responses != null) {
173             responses.add(answer);
174         }
175     }
176 
177     @Override
178     public int hashCode() {
179         return getId().hashCode();
180     }
181 
182     @Override
183     public boolean equals(Object o) {
184         if (o == this) {
185             return true;
186         }
187 
188         if (o == null) {
189             return false;
190         }
191 
192         if (!(o instanceof Request)) {
193             return false;
194         }
195 
196         Request that = (Request) o;
197         return this.getId().equals(that.getId());
198     }
199 
200     @Override
201     public String toString() {
202         String timeout = getTimeoutMillis() == Long.MAX_VALUE ? "max"
203                 : String.valueOf(getTimeoutMillis());
204 
205         return "request: { id=" + getId() + ", timeout=" + timeout
206                 + ", message=" + getMessage() + " }";
207     }
208 
209     Runnable getTimeoutTask() {
210         return timeoutTask;
211     }
212 
213     void setTimeoutTask(Runnable timeoutTask) {
214         this.timeoutTask = timeoutTask;
215     }
216 
217     ScheduledFuture<?> getTimeoutFuture() {
218         return timeoutFuture;
219     }
220 
221     void setTimeoutFuture(ScheduledFuture<?> timeoutFuture) {
222         this.timeoutFuture = timeoutFuture;
223     }
224 }