1 /**
2 * Copyright (c) 2012, University of Konstanz, Distributed Systems Group All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without modification, are permitted provided that the
5 * following conditions are met: * Redistributions of source code must retain the above copyright notice, this list of
6 * conditions and the following disclaimer. * Redistributions in binary form must reproduce the above copyright notice,
7 * this list of conditions and the following disclaimer in the documentation and/or other materials provided with the
8 * distribution. * Neither the name of the University of Konstanz nor the names of its contributors may be used to
9 * endorse or promote products derived from this software without specific prior written permission.
10 *
11 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
12 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
13 * DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
14 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
15 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
16 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
17 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
18 */
19 package org.jscsi.initiator.connection.state;
20
21
22 import org.jscsi.exception.InternetSCSIException;
23 import org.jscsi.initiator.connection.Connection;
24 import org.jscsi.parser.ProtocolDataUnit;
25 import org.jscsi.parser.ProtocolDataUnitFactory;
26 import org.slf4j.Logger;
27 import org.slf4j.LoggerFactory;
28
29
30 /**
31 * <h1>IState</h1>
32 * <p/>
33 * Each inherited state must implement this interface.
34 *
35 * @author Volker Wildi
36 */
37 public interface IState {
38
39 // --------------------------------------------------------------------------
40 // --------------------------------------------------------------------------
41
42 /**
43 * This method is always invoked, when a request message must be send or response message must be received and then
44 * parsed.
45 *
46 * @throws InternetSCSIException if any violation of the iSCSI Standard (RfC3720) has emerged.
47 */
48 public void execute () throws InternetSCSIException;
49
50 /**
51 * This method shows if another state is following this one.
52 *
53 * @return <code>true</code>, if another state must follow this state. Else an final state is reached.
54 */
55 public boolean nextStateFollowing ();
56
57 /**
58 * This method checks the correctness of the given <code>ProtocolDataUnit</code> instance within the current state
59 * of a connection.
60 *
61 * @param protocolDataUnit The <code>ProtocolDataUnit</code> instance to check.
62 * @return <code>Exception</code> if any problem occured with the PDU, <code>null</code> otherwise.
63 */
64 public Exception isCorrect (final ProtocolDataUnit protocolDataUnit);
65
66 // --------------------------------------------------------------------------
67 // --------------------------------------------------------------------------
68 // --------------------------------------------------------------------------
69 // --------------------------------------------------------------------------
70
71 }
72
73
74 /**
75 * <h1>AbstractState</h1>
76 * <p/>
77 * Each connection state must extend this abstract class to support some basic features.
78 *
79 * @author Volker Wildi
80 */
81 abstract class AbstractState implements IState {
82
83 // --------------------------------------------------------------------------
84 // --------------------------------------------------------------------------
85
86 /** The Logger interface. */
87 protected static final Logger LOGGER = LoggerFactory.getLogger(AbstractState.class);
88
89 // --------------------------------------------------------------------------
90 // --------------------------------------------------------------------------
91
92 /** The context connection used by all message kinds. */
93 protected final Connection connection;
94
95 /** Factory to create the <code>ProtocolDataUnit</code> instances. */
96 protected final ProtocolDataUnitFactory protocolDataUnitFactory = new ProtocolDataUnitFactory();
97
98 /** boolean to mark following states. */
99 protected boolean stateFollowing;
100
101 // --------------------------------------------------------------------------
102 // --------------------------------------------------------------------------
103
104 /** {@inheritDoc} */
105 public Exception isCorrect (final ProtocolDataUnit protocolDataUnit) {
106
107 return null;
108 }
109
110 // --------------------------------------------------------------------------
111 // --------------------------------------------------------------------------
112
113 /**
114 * Constructor, which each subclass must implement to set the context connection correctly.
115 *
116 * @param initConnection The connection, which is used for the message transmission.
117 */
118 protected AbstractState (final Connection initConnection) {
119
120 connection = initConnection;
121 }
122
123 /**
124 * {@inheritDoc}
125 */
126 public boolean nextStateFollowing () {
127 return this.stateFollowing;
128 }
129
130 // --------------------------------------------------------------------------
131 // --------------------------------------------------------------------------
132 // --------------------------------------------------------------------------
133 // --------------------------------------------------------------------------
134
135 }