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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  
21  package org.apache.james.util;
22  
23  import org.apache.avalon.cornerstone.services.scheduler.TimeScheduler;
24  
25  import java.io.IOException;
26  import java.io.OutputStream;
27  
28  /***
29   * This will reset the scheduler each time a certain amount of data has
30   * been transfered.  This allows us to keep the timeout settings low, while
31   * not timing out during large data transfers.
32   */
33  public class SchedulerNotifyOutputStream extends OutputStream {
34  
35      /***
36       * The output stream wrapped by this method
37       */
38      OutputStream out = null;
39  
40      /***
41       * The scheduler used by this class to timeout
42       */
43      TimeScheduler scheduler = null;
44  
45      /***
46       * The name of the trigger
47       */
48      String triggerName = null;
49  
50      /***
51       * The number of bytes that need to be written before the counter is reset.
52       */
53      int lengthReset = 0;
54  
55      /***
56       * The number of bytes written since the counter was last reset
57       */
58      int writtenCounter = 0;
59  
60      public SchedulerNotifyOutputStream(OutputStream out,
61              TimeScheduler scheduler, String triggerName, int lengthReset) {
62          this.out = out;
63          this.scheduler = scheduler;
64          this.triggerName = triggerName;
65          this.lengthReset = lengthReset;
66  
67          writtenCounter = 0;
68      }
69  
70      /***
71       * Write an array of bytes to the stream
72       *
73       * @param b the array of bytes to write to the stream
74       * @param off the index in the array where we start writing
75       * @param len the number of bytes of the array to write
76       *
77       * @throws IOException if an exception is encountered when writing
78       */
79      public void write(byte[] b, int off, int len) throws IOException {
80          out.write(b, off, len);
81          writtenCounter += len;
82  
83          if (writtenCounter > lengthReset) {
84              writtenCounter -= lengthReset;
85              scheduler.resetTrigger(triggerName);
86          }
87      }
88  
89      /***
90       * Write a byte to the stream
91       *
92       * @param b the byte to write to the stream
93       *
94       * @throws IOException if an exception is encountered when writing
95       */
96      public void write(int b) throws IOException {
97          out.write(b);
98          writtenCounter++;
99  
100         if (writtenCounter > lengthReset) {
101             writtenCounter -= lengthReset;
102             scheduler.resetTrigger(triggerName);
103         }
104     }
105 
106     /***
107      * Flush the stream
108      *
109      * @throws IOException if an exception is encountered when flushing
110      */
111     public void flush() throws IOException {
112         out.flush();
113     }
114 
115     /***
116      * Close the stream
117      *
118      * @throws IOException if an exception is encountered when closing
119      */
120     public void close() throws IOException {
121         out.close();
122     }
123 }