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     public AppendEntries(long term, String leaderId, long prevLogIndex,
  54         long prevLogTerm, List<ReplicatedLogEntry> entries, long leaderCommit) {
  55         super(term);
  56         this.leaderId = leaderId;
  57         this.prevLogIndex = prevLogIndex;
  58         this.prevLogTerm = prevLogTerm;
  59         this.entries = entries;
  60         this.leaderCommit = leaderCommit;
  61     }
  62
  63     private void writeObject(ObjectOutputStream out) throws IOException {
  64         out.writeShort(RaftVersions.CURRENT_VERSION);
  65         out.defaultWriteObject();
  66
  67         out.writeInt(entries.size());
  68         for(ReplicatedLogEntry e: entries) {
  69             out.writeObject(e);
  70         }
  71     }
  72
  73     private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
  74         in.readShort(); // version
  75
  76         in.defaultReadObject();
  77
  78         int size = in.readInt();
  79         entries = new ArrayList<>(size);
  80         for(int i = 0; i < size; i++) {
  81             entries.add((ReplicatedLogEntry) in.readObject());
  82         }
  83     }
  84
  85     public String getLeaderId() {
  86         return leaderId;
  87     }
  88
  89     public long getPrevLogIndex() {
  90         return prevLogIndex;
  91     }
  92
  93     public long getPrevLogTerm() {
  94         return prevLogTerm;
  95     }
  96
  97     public List<ReplicatedLogEntry> getEntries() {
  98         return entries;
  99     }
 100
 101     public long getLeaderCommit() {
 102         return leaderCommit;
 103     }
 104
 105     @Override
 106     public String toString() {
 107         final StringBuilder sb =
 108             new StringBuilder("AppendEntries{");
 109         sb.append("term=").append(getTerm());
 110         sb.append("leaderId='").append(leaderId).append('\'');
 111         sb.append(", prevLogIndex=").append(prevLogIndex);
 112         sb.append(", prevLogTerm=").append(prevLogTerm);
 113         sb.append(", entries=").append(entries);
 114         sb.append(", leaderCommit=").append(leaderCommit);
 115         sb.append('}');
 116         return sb.toString();
 117     }
 118
 119     public <T extends Object> Object toSerializable() {
 120         return toSerializable(RaftVersions.CURRENT_VERSION);
 121     }
 122
 123     public <T extends Object> Object toSerializable(short version) {
 124         if(version < RaftVersions.LITHIUM_VERSION) {
 125             return toLegacySerializable();
 126         } else {
 127             return this;
 128         }
 129     }
 130
 131     @SuppressWarnings({ "rawtypes", "unchecked" })
 132     private <T> Object toLegacySerializable() {
 133         AppendEntriesMessages.AppendEntries.Builder to = AppendEntriesMessages.AppendEntries.newBuilder();
 134         to.setTerm(this.getTerm())
 135             .setLeaderId(this.getLeaderId())
 136             .setPrevLogTerm(this.getPrevLogTerm())
 137             .setPrevLogIndex(this.getPrevLogIndex())
 138             .setLeaderCommit(this.getLeaderCommit());
 139
 140         for (ReplicatedLogEntry logEntry : this.getEntries()) {
 141
 142             AppendEntriesMessages.AppendEntries.ReplicatedLogEntry.Builder arBuilder =
 143                 AppendEntriesMessages.AppendEntries.ReplicatedLogEntry.newBuilder();
 144
 145             AppendEntriesMessages.AppendEntries.ReplicatedLogEntry.Payload.Builder arpBuilder =
 146                 AppendEntriesMessages.AppendEntries.ReplicatedLogEntry.Payload.newBuilder();
 147
 148             //get the client specific payload extensions and add them to the payload builder
 149             Map<GeneratedMessage.GeneratedExtension, T> map = logEntry.getData().encode();
 150             Iterator<Map.Entry<GeneratedMessage.GeneratedExtension, T>> iter = map.entrySet().iterator();
 151
 152             while (iter.hasNext()) {
 153                 Map.Entry<GeneratedMessage.GeneratedExtension, T> entry = iter.next();
 154                 arpBuilder.setExtension(entry.getKey(), entry.getValue());
 155             }
 156
 157             arpBuilder.setClientPayloadClassName(logEntry.getData().getClientPayloadClassName());
 158
 159             arBuilder.setData(arpBuilder).setIndex(logEntry.getIndex()).setTerm(logEntry.getTerm());
 160             to.addLogEntries(arBuilder);
 161         }
 162
 163         return to.build();
 164     }
 165
 166     public static AppendEntries fromSerializable(Object serialized) {
 167         if(serialized instanceof AppendEntries) {
 168             return (AppendEntries)serialized;
 169         }
 170         else {
 171             return fromLegacySerializable((AppendEntriesMessages.AppendEntries) serialized);
 172         }
 173     }
 174
 175     private static AppendEntries fromLegacySerializable(AppendEntriesMessages.AppendEntries from) {
 176         List<ReplicatedLogEntry> logEntryList = new ArrayList<>();
 177         for (AppendEntriesMessages.AppendEntries.ReplicatedLogEntry leProtoBuff : from.getLogEntriesList()) {
 178
 179             Payload payload = null ;
 180             try {
 181                 if(leProtoBuff.getData() != null && leProtoBuff.getData().getClientPayloadClassName() != null) {
 182                     String clientPayloadClassName = leProtoBuff.getData().getClientPayloadClassName();
 183                     payload = (Payload) Class.forName(clientPayloadClassName).newInstance();
 184                     payload = payload.decode(leProtoBuff.getData());
 185                 } else {
 186                     LOG.error("Payload is null or payload does not have client payload class name");
 187                 }
 188
 189             } catch (InstantiationException e) {
 190                 LOG.error("InstantiationException when instantiating "+leProtoBuff.getData().getClientPayloadClassName(), e);
 191             } catch (IllegalAccessException e) {
 192                 LOG.error("IllegalAccessException when accessing "+leProtoBuff.getData().getClientPayloadClassName(), e);
 193             } catch (ClassNotFoundException e) {
 194                 LOG.error("ClassNotFoundException when loading "+leProtoBuff.getData().getClientPayloadClassName(), e);
 195             }
 196             ReplicatedLogEntry logEntry = new ReplicatedLogImplEntry(
 197                 leProtoBuff.getIndex(), leProtoBuff.getTerm(), payload);
 198             logEntryList.add(logEntry);
 199         }
 200
 201         AppendEntries to = new AppendEntries(from.getTerm(),
 202             from.getLeaderId(),
 203             from.getPrevLogIndex(),
 204             from.getPrevLogTerm(),
 205             logEntryList,
 206             from.getLeaderCommit());
 207
 208         return to;
 209     }
 210
 211     public static boolean isSerializedType(Object message) {
 212         return message instanceof AppendEntries || LEGACY_SERIALIZABLE_CLASS.isInstance(message);
 213     }
 214 }