1 /************************************************************************
2 * Copyright (c) 2000-2006 The Apache Software Foundation. *
3 * All rights reserved. *
4 * ------------------------------------------------------------------- *
5 * Licensed under the Apache License, Version 2.0 (the "License"); you *
6 * may not use this file except in compliance with the License. You *
7 * may obtain a copy of the License at: *
8 * *
9 * http://www.apache.org/licenses/LICENSE-2.0 *
10 * *
11 * Unless required by applicable law or agreed to in writing, software *
12 * distributed under the License is distributed on an "AS IS" BASIS, *
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or *
14 * implied. See the License for the specific language governing *
15 * permissions and limitations under the License. *
16 ***********************************************************************/
17
18
19 package org.apache.james.util;
20
21 import org.apache.avalon.cornerstone.services.scheduler.TimeScheduler;
22
23 import java.io.IOException;
24 import java.io.InputStream;
25
26 /***
27 * This will reset the scheduler each time a certain amount of data has
28 * been transfered. This allows us to keep the timeout settings low, while
29 * not timing out during large data transfers.
30 */
31 public class SchedulerNotifyInputStream extends InputStream {
32
33 /***
34 * The wrapped InputStream
35 */
36 InputStream in = null;
37
38 /***
39 * The scheduler managing the trigger to be reset by this stream
40 */
41 TimeScheduler scheduler = null;
42
43 /***
44 * The name of the trigger
45 */
46 String triggerName = null;
47
48 /***
49 * The number of bytes that need to be read before the counter is reset.
50 */
51 int lengthReset = 0;
52
53 /***
54 * The number of bytes read since the counter was last reset
55 */
56 int readCounter = 0;
57
58 /***
59 * @param in the InputStream to be wrapped by this stream
60 * @param scheduler the TimeScheduler managing the trigger to be reset by this stream
61 * @param triggerName the name of the particular trigger to be reset by this stream
62 * @param lengthReset the number of bytes to be read in between trigger resets
63 */
64 public SchedulerNotifyInputStream(InputStream in,
65 TimeScheduler scheduler, String triggerName, int lengthReset) {
66 this.in = in;
67 this.scheduler = scheduler;
68 this.triggerName = triggerName;
69 this.lengthReset = lengthReset;
70
71 readCounter = 0;
72 }
73
74 /***
75 * Read an array of bytes from the stream
76 *
77 * @param b the array of bytes to read from the stream
78 * @param off the index in the array where we start writing
79 * @param len the number of bytes of the array to read
80 *
81 * @return the number of bytes read
82 *
83 * @throws IOException if an exception is encountered when reading
84 */
85 public int read(byte[] b, int off, int len) throws IOException {
86 int l = in.read(b, off, len);
87 readCounter += l;
88
89 if (readCounter > lengthReset) {
90 readCounter -= lengthReset;
91 scheduler.resetTrigger(triggerName);
92 }
93
94 return l;
95 }
96
97 /***
98 * Read a byte from the stream
99 *
100 * @return the byte read from the stream
101 * @throws IOException if an exception is encountered when reading
102 */
103 public int read() throws IOException {
104 int b = in.read();
105 readCounter++;
106
107 if (readCounter > lengthReset) {
108 readCounter -= lengthReset;
109 scheduler.resetTrigger(triggerName);
110 }
111
112 return b;
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 in.close();
122 }
123 }