opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/messages/AppendEntries.java

   1 /*
   2  * Copyright (c) 2014 Cisco Systems, Inc. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8
   9 package org.opendaylight.controller.cluster.raft.messages;
  10
  11 import com.google.protobuf.GeneratedMessage;
  12 import java.io.IOException;
  13 import java.io.ObjectInputStream;
  14 import java.io.ObjectOutputStream;
  15 import java.util.ArrayList;
  16 import java.util.Iterator;
  17 import java.util.List;
  18 import java.util.Map;
  19 import org.opendaylight.controller.cluster.raft.RaftVersions;
  20 import org.opendaylight.controller.cluster.raft.ReplicatedLogEntry;
  21 import org.opendaylight.controller.cluster.raft.ReplicatedLogImplEntry;
  22 import org.opendaylight.controller.cluster.raft.protobuff.client.messages.Payload;
  23 import org.opendaylight.controller.protobuff.messages.cluster.raft.AppendEntriesMessages;
  24
  25 /**
  26  * Invoked by leader to replicate log entries (§5.3); also used as
  27  * heartbeat (§5.2).
  28  */
  29 public class AppendEntries extends AbstractRaftRPC {
  30     private static final long serialVersionUID = 1L;
  31
  32     public static final Class<AppendEntriesMessages.AppendEntries> LEGACY_SERIALIZABLE_CLASS =
  33             AppendEntriesMessages.AppendEntries.class;
  34
  35     private static final org.slf4j.Logger LOG = org.slf4j.LoggerFactory.getLogger(AppendEntries.class);
  36
  37     // So that follower can redirect clients
  38     private final String leaderId;
  39
  40     // Index of log entry immediately preceding new ones
  41     private final long prevLogIndex;
  42
  43     // term of prevLogIndex entry
  44     private final long prevLogTerm;
  45
  46     // log entries to store (empty for heartbeat;
  47     // may send more than one for efficiency)
  48     private transient List<ReplicatedLogEntry> entries;
  49
  50     // leader's commitIndex
  51     private final long leaderCommit;
  52
  53     // index which has been replicated successfully to all followers, -1 if none
  54     private final long replicatedToAllIndex;
  55
  56     public AppendEntries(long term, String leaderId, long prevLogIndex,
  57         long prevLogTerm, List<ReplicatedLogEntry> entries, long leaderCommit, long replicatedToAllIndex) {
  58         super(term);
  59         this.leaderId = leaderId;
  60         this.prevLogIndex = prevLogIndex;
  61         this.prevLogTerm = prevLogTerm;
  62         this.entries = entries;
  63         this.leaderCommit = leaderCommit;
  64         this.replicatedToAllIndex = replicatedToAllIndex;
  65     }
  66
  67     private void writeObject(ObjectOutputStream out) throws IOException {
  68         out.writeShort(RaftVersions.CURRENT_VERSION);
  69         out.defaultWriteObject();
  70
  71         out.writeInt(entries.size());
  72         for(ReplicatedLogEntry e: entries) {
  73             out.writeObject(e);
  74         }
  75     }
  76
  77     private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
  78         in.readShort(); // version
  79
  80         in.defaultReadObject();
  81
  82         int size = in.readInt();
  83         entries = new ArrayList<>(size);
  84         for(int i = 0; i < size; i++) {
  85             entries.add((ReplicatedLogEntry) in.readObject());
  86         }
  87     }
  88
  89     public String getLeaderId() {
  90         return leaderId;
  91     }
  92
  93     public long getPrevLogIndex() {
  94         return prevLogIndex;
  95     }
  96
  97     public long getPrevLogTerm() {
  98         return prevLogTerm;
  99     }
 100
 101     public List<ReplicatedLogEntry> getEntries() {
 102         return entries;
 103     }
 104
 105     public long getLeaderCommit() {
 106         return leaderCommit;
 107     }
 108
 109     public long getReplicatedToAllIndex() {
 110         return replicatedToAllIndex;
 111     }
 112
 113
 114     @Override
 115     public String toString() {
 116         StringBuilder builder = new StringBuilder();
 117         builder.append("AppendEntries [term=").append(term).append(", leaderId=").append(leaderId)
 118                 .append(", prevLogIndex=").append(prevLogIndex).append(", prevLogTerm=").append(prevLogTerm)
 119                 .append(", entries=").append(entries).append(", leaderCommit=").append(leaderCommit)
 120                 .append(", replicatedToAllIndex=").append(replicatedToAllIndex).append("]");
 121         return builder.toString();
 122     }
 123
 124     public <T extends Object> Object toSerializable() {
 125         return toSerializable(RaftVersions.CURRENT_VERSION);
 126     }
 127
 128     public <T extends Object> Object toSerializable(short version) {
 129         if(version < RaftVersions.LITHIUM_VERSION) {
 130             return toLegacySerializable();
 131         } else {
 132             return this;
 133         }
 134     }
 135
 136     @SuppressWarnings({ "rawtypes", "unchecked" })
 137     private <T> Object toLegacySerializable() {
 138         AppendEntriesMessages.AppendEntries.Builder to = AppendEntriesMessages.AppendEntries.newBuilder();
 139         to.setTerm(this.getTerm())
 140             .setLeaderId(this.getLeaderId())
 141             .setPrevLogTerm(this.getPrevLogTerm())
 142             .setPrevLogIndex(this.getPrevLogIndex())
 143             .setLeaderCommit(this.getLeaderCommit());
 144
 145         for (ReplicatedLogEntry logEntry : this.getEntries()) {
 146
 147             AppendEntriesMessages.AppendEntries.ReplicatedLogEntry.Builder arBuilder =
 148                 AppendEntriesMessages.AppendEntries.ReplicatedLogEntry.newBuilder();
 149
 150             AppendEntriesMessages.AppendEntries.ReplicatedLogEntry.Payload.Builder arpBuilder =
 151                 AppendEntriesMessages.AppendEntries.ReplicatedLogEntry.Payload.newBuilder();
 152
 153             //get the client specific payload extensions and add them to the payload builder
 154             Map<GeneratedMessage.GeneratedExtension, T> map = logEntry.getData().encode();
 155             Iterator<Map.Entry<GeneratedMessage.GeneratedExtension, T>> iter = map.entrySet().iterator();
 156
 157             while (iter.hasNext()) {
 158                 Map.Entry<GeneratedMessage.GeneratedExtension, T> entry = iter.next();
 159                 arpBuilder.setExtension(entry.getKey(), entry.getValue());
 160             }
 161
 162             arpBuilder.setClientPayloadClassName(logEntry.getData().getClientPayloadClassName());
 163
 164             arBuilder.setData(arpBuilder).setIndex(logEntry.getIndex()).setTerm(logEntry.getTerm());
 165             to.addLogEntries(arBuilder);
 166         }
 167
 168         return to.build();
 169     }
 170
 171     public static AppendEntries fromSerializable(Object serialized) {
 172         if(serialized instanceof AppendEntries) {
 173             return (AppendEntries)serialized;
 174         }
 175         else {
 176             return fromLegacySerializable((AppendEntriesMessages.AppendEntries) serialized);
 177         }
 178     }
 179
 180     private static AppendEntries fromLegacySerializable(AppendEntriesMessages.AppendEntries from) {
 181         List<ReplicatedLogEntry> logEntryList = new ArrayList<>();
 182         for (AppendEntriesMessages.AppendEntries.ReplicatedLogEntry leProtoBuff : from.getLogEntriesList()) {
 183
 184             Payload payload = null ;
 185             try {
 186                 if(leProtoBuff.getData() != null && leProtoBuff.getData().getClientPayloadClassName() != null) {
 187                     String clientPayloadClassName = leProtoBuff.getData().getClientPayloadClassName();
 188                     payload = (Payload) Class.forName(clientPayloadClassName).newInstance();
 189                     payload = payload.decode(leProtoBuff.getData());
 190                 } else {
 191                     LOG.error("Payload is null or payload does not have client payload class name");
 192                 }
 193
 194             } catch (InstantiationException e) {
 195                 LOG.error("InstantiationException when instantiating "+leProtoBuff.getData().getClientPayloadClassName(), e);
 196             } catch (IllegalAccessException e) {
 197                 LOG.error("IllegalAccessException when accessing "+leProtoBuff.getData().getClientPayloadClassName(), e);
 198             } catch (ClassNotFoundException e) {
 199                 LOG.error("ClassNotFoundException when loading "+leProtoBuff.getData().getClientPayloadClassName(), e);
 200             }
 201             ReplicatedLogEntry logEntry = new ReplicatedLogImplEntry(
 202                 leProtoBuff.getIndex(), leProtoBuff.getTerm(), payload);
 203             logEntryList.add(logEntry);
 204         }
 205
 206         AppendEntries to = new AppendEntries(from.getTerm(),
 207             from.getLeaderId(),
 208             from.getPrevLogIndex(),
 209             from.getPrevLogTerm(),
 210             logEntryList,
 211             from.getLeaderCommit(), -1);
 212
 213         return to;
 214     }
 215
 216     public static boolean isSerializedType(Object message) {
 217         return message instanceof AppendEntries || LEGACY_SERIALIZABLE_CLASS.isInstance(message);
 218     }
 219 }