1 /***
2 * Jetrix TetriNET Server
3 * Copyright (C) 2005 Emmanuel Bourg
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License
7 * as published by the Free Software Foundation; either version 2
8 * of the License, or (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
18 */
19
20 package net.jetrix.protocols;
21
22 import java.io.ByteArrayOutputStream;
23 import java.io.IOException;
24 import java.io.InputStream;
25
26 import net.jetrix.Protocol;
27
28 /***
29 * Abstract protocol implementing the readLine(Reader) method.
30 *
31 * @since 0.3
32 *
33 * @author Emmanuel Bourg
34 * @version $Revision: 848 $, $Date: 2010-05-03 22:51:32 +0200 (lun., 03 mai 2010) $
35 */
36 public abstract class AbstractProtocol implements Protocol
37 {
38 /*** Maximum size allowed for a message frame. */
39 private static final int MAX_SIZE = 8192;
40
41 /*** Maximum delay allowed for parsing a message frame (in milliseconds). */
42 private static final int MAX_DELAY = 10000;
43
44 /***
45 * Reads the next message frame from the specified input stream.
46 * No charset decoding is performed at this stage.
47 */
48 public byte[] readFrame(InputStream in) throws IOException
49 {
50 ByteArrayOutputStream input = new ByteArrayOutputStream(256);
51
52 long time = 0;
53
54 int b;
55 while ((b = in.read()) != -1 && b != getEOL() && b != 0x0A && b != 0x0D && input.size() < MAX_SIZE)
56 {
57 input.write(b);
58
59 if (input.size() == 1)
60 {
61
62 time = System.currentTimeMillis();
63 }
64 else if (System.currentTimeMillis() - time > MAX_DELAY)
65 {
66 throw new IOException("Slow input detected (" + input.size() + " bytes over " + (System.currentTimeMillis() - time) + "ms)");
67 }
68 }
69
70 if (b == -1)
71 {
72 throw new IOException("End of stream");
73 }
74
75 if (input.size() >= MAX_SIZE)
76 {
77 throw new IOException("Message frame exceeded the " + MAX_SIZE + " limit");
78 }
79
80 return input.toByteArray();
81 }
82
83 public String readLine(InputStream in, String encoding) throws IOException
84 {
85 return new String(readFrame(in), encoding);
86 }
87
88 public boolean equals(Object o)
89 {
90 if (this == o)
91 {
92 return true;
93 }
94 if (o == null || getClass() != o.getClass())
95 {
96 return false;
97 }
98
99 Protocol that = (Protocol) o;
100
101 if (!getName().equals(that.getName()))
102 {
103 return false;
104 }
105
106 return true;
107 }
108
109 public int hashCode()
110 {
111 return getName().hashCode();
112 }
113
114 public String toString()
115 {
116 return "[Protocol name=" + getName() + "]";
117 }
118 }