1 /*
2 * Copyright (c) 1998-2002 The Jgroup Team.
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU Lesser General Public License version 2 as
6 * published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU Lesser General Public License for more details.
12 *
13 * You should have received a copy of the GNU Lesser General Public License
14 * along with this program; if not, write to the Free Software
15 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
16 *
17 */
18
19 package jgroup.relacs.daemon;
20
21
22 import java.io.IOException;
23 import java.io.ObjectInput;
24
25 import jgroup.core.EndPoint;
26 import jgroup.relacs.mss.MssConstants;
27 import jgroup.relacs.types.EndPointImpl;
28 import jgroup.relacs.types.GroupId;
29 import jgroup.relacs.types.GroupIndex;
30 import jgroup.relacs.types.IncarnationId;
31 import jgroup.relacs.types.LocalId;
32 import jgroup.relacs.types.MessageLen;
33 import jgroup.relacs.types.VersionId;
34 import jgroup.relacs.types.ViewId;
35 import jgroup.util.InMessage;
36 import jgroup.util.MsgFactory;
37 import jgroup.util.OutMessage;
38
39
40 /**
41 * The <code> MsgView</code> class
42 *
43 * @author Alberto Montresor
44 * @since Jgroup 0.1
45 */
46 final class MsgView
47 implements MssConstants, DaemonMsg
48 {
49
50 ////////////////////////////////////////////////////////////////////////////////////////////
51 // Position constants
52 ////////////////////////////////////////////////////////////////////////////////////////////
53
54 private static final int START = MSS_HEADER_SIZE;
55
56
57 ////////////////////////////////////////////////////////////////////////////////////////////
58 // Unique message instance
59 ////////////////////////////////////////////////////////////////////////////////////////////
60
61 /**
62 * As these messages are never stored by the daemon, a single message
63 * instance is sufficient. In this way, we save the costs of
64 * allocating and garbage collecting messages.
65 */
66 private static MsgView msg = new MsgView();
67
68 /** The marshalled message data (also static for same reason as above) */
69 private static OutMessage outmsg;
70
71
72 ////////////////////////////////////////////////////////////////////////////////////////////
73 // Fields
74 ////////////////////////////////////////////////////////////////////////////////////////////
75
76 /** Original stream received from a coordinator, used to resend messages. */
77 InMessage stream;
78
79 /** New complete view identifier */
80 long cvid;
81
82 /** New compete view composition */
83 EndPoint[] cvcomp;
84
85 /** */
86 int[] incarns;
87
88 /** Agreed version numbers */
89 int[] agreed;
90
91 /** Partial view identifiers */
92 int[] pvids;
93
94 /** Members tables */
95 LocalId[][] members;
96
97 /** MsgView message size (excluding the mss header) */
98 private int size;
99
100
101 ////////////////////////////////////////////////////////////////////////////////////////////
102 // Decoding methods
103 ////////////////////////////////////////////////////////////////////////////////////////////
104
105 /**
106 * Returns a <code>MsgView</code> object that contains the decoding
107 * of the m-received input stream.
108 *
109 * @param stream the message input stream to decode
110 */
111 static MsgView unmarshal(ObjectInput stream)
112 throws IOException, ClassNotFoundException
113 {
114 msg.stream = (InMessage) stream;
115 msg.cvid = ViewId.unmarshal(stream);
116 msg.size = MessageLen.unmarshal(stream);
117 int len = GroupIndex.unmarshal(stream);
118 msg.cvcomp = new EndPoint[len];
119 msg.incarns = new int[len];
120 msg.agreed = new int[len];
121 msg.pvids = new int[len];
122 msg.members = new LocalId[len][];
123 for (int i=0; i < len; i++) {
124 msg.cvcomp[i] = new EndPointImpl();
125 msg.cvcomp[i].readExternal(stream);
126 }
127 for (int i=0; i < len; i++)
128 msg.incarns[i] = IncarnationId.unmarshal(stream);
129 for (int i=0; i < len; i++)
130 msg.agreed[i] = VersionId.unmarshal(stream);
131 for (int i=0; i < len; i++)
132 msg.pvids[i] = GroupIndex.unmarshal(stream);
133 for (int i=0; i < len; i++) {
134 msg.members[i] = new LocalId[GroupIndex.unmarshal(stream)];
135 for (int j=0; j < msg.members[i].length; j++) {
136 msg.members[i][j] = new LocalId();
137 msg.members[i][j].readExternal(stream);
138 }
139 }
140 return msg;
141 }
142
143 ////////////////////////////////////////////////////////////////////////////////////////////
144 // Message to send
145 ////////////////////////////////////////////////////////////////////////////////////////////
146
147 /**
148 * Encode a message starting from a previously received message.
149 */
150 MsgView marshal()
151 {
152 outmsg = new OutMessage(stream);
153 return msg;
154 }
155
156
157 /**
158 * Returns a output stream containing the encoding of a
159 * <code>MsgView</code> message.
160 *
161 * @param gid group identifier
162 * @param cvid identifier of the current complete view
163 * @param prop proposal on which the agreement has been reached
164 * @param pvids identifiers of previous partial views (needed to compute new partial
165 * views
166 * @param props proposal array (containing members lists)
167 */
168 static MsgView marshal(int gid, long cvid, MsgProp prop, int[] pvids,
169 MsgProp[] props, int nreceivers)
170 throws IOException
171 {
172 // Allocates data buffer
173 msg.size = GroupId.SIZE + ViewId.SIZE + MessageLen.SIZE + GroupIndex.SIZE
174 + prop.host_plen + pvids.length * GroupIndex.SIZE;
175 for (int i=0; i < props.length; i++)
176 msg.size += props[i].memb_plen;
177 outmsg = MsgFactory.get(START + msg.size, nreceivers);
178 outmsg.seek(START);
179
180 // Writes single data
181 GroupId.marshal(outmsg, gid);
182 /*
183 * There should've been a GroupIndex.marshal() here, but this is
184 * instead in MsgProp.encodeHostProp().
185 */
186 ViewId.marshal(outmsg, cvid);
187 MessageLen.marshal(outmsg, msg.size);
188
189 // Copies composition and agreed values
190 prop.stream.seek(prop.host_start);
191 byte[] tempbuffer = new byte[prop.host_plen];
192 prop.stream.read(tempbuffer);
193 outmsg.write(tempbuffer);
194
195 // Writes coordinator table informations
196 for (int i=0; i < pvids.length; i++)
197 GroupIndex.marshal(outmsg, pvids[i]);
198 for (int i=0; i < props.length; i++) {
199 props[i].stream.seek(props[i].memb_start);
200 tempbuffer = new byte[props[i].memb_plen];
201 props[i].stream.read(tempbuffer);
202 outmsg.write(tempbuffer);
203 }
204 return msg;
205 }
206
207
208 ////////////////////////////////////////////////////////////////////////////////////////////
209 // Methods from DaemonMsg
210 ////////////////////////////////////////////////////////////////////////////////////////////
211
212 public int size()
213 {
214 return size;
215 }
216
217 public OutMessage getOutMessage()
218 {
219 return outmsg;
220 }
221
222
223 ////////////////////////////////////////////////////////////////////////////////////////////
224 // Methods from Object
225 ////////////////////////////////////////////////////////////////////////////////////////////
226
227 /**
228 * Returns a string representation of this object
229 */
230 public String toString()
231 {
232 StringBuilder buffer = new StringBuilder();
233 buffer.append("[MsgView: cvid=");
234 buffer.append(cvid);
235 buffer.append(", cvcomp={");
236 for (int i=0; i < cvcomp.length; i++) {
237 buffer.append(cvcomp[i]);
238 if (i < cvcomp.length-1)
239 buffer.append(", ");
240 }
241 buffer.append("}, agreed={");
242 for (int i=0; i < agreed.length; i++) {
243 buffer.append(agreed[i]);
244 if (i < agreed.length-1)
245 buffer.append(", ");
246 }
247 buffer.append("}, pvids={");
248 for (int i=0; i < pvids.length; i++) {
249 buffer.append(pvids[i]);
250 if (i < pvids.length-1)
251 buffer.append(", ");
252 }
253 buffer.append("}, members={");
254 for (int i=0; i < members.length; i++) {
255 buffer.append("{");
256 for (int j=0; j < members[i].length; j++) {
257 buffer.append(members[i][j]);
258 if (j < members[i].length-1)
259 buffer.append(",");
260 }
261 buffer.append("}");
262 if (i < members.length-1)
263 buffer.append(",");
264 }
265 buffer.append("}]");
266 return buffer.toString();
267 }
268
269 } // END MsgView
270