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 java.io.Externalizable;
  12 import java.io.IOException;
  13 import java.io.ObjectInput;
  14 import java.io.ObjectOutput;
  15 import java.util.ArrayList;
  16 import java.util.List;
  17 import org.opendaylight.controller.cluster.raft.ReplicatedLogEntry;
  18 import org.opendaylight.controller.cluster.raft.persisted.SimpleReplicatedLogEntry;
  19 import org.opendaylight.controller.cluster.raft.protobuff.client.messages.Payload;
  20
  21 /**
  22  * Invoked by leader to replicate log entries (§5.3); also used as
  23  * heartbeat (§5.2).
  24  */
  25 public class AppendEntries extends AbstractRaftRPC {
  26     private static final long serialVersionUID = 1L;
  27
  28     // So that follower can redirect clients
  29     private final String leaderId;
  30
  31     // Index of log entry immediately preceding new ones
  32     private final long prevLogIndex;
  33
  34     // term of prevLogIndex entry
  35     private final long prevLogTerm;
  36
  37     // log entries to store (empty for heart beat - may send more than one for efficiency)
  38     private final List<ReplicatedLogEntry> entries;
  39
  40     // leader's commitIndex
  41     private final long leaderCommit;
  42
  43     // index which has been replicated successfully to all followers, -1 if none
  44     private final long replicatedToAllIndex;
  45
  46     private final short payloadVersion;
  47
  48     public AppendEntries(long term, String leaderId, long prevLogIndex, long prevLogTerm,
  49             List<ReplicatedLogEntry> entries, long leaderCommit, long replicatedToAllIndex, short payloadVersion) {
  50         super(term);
  51         this.leaderId = leaderId;
  52         this.prevLogIndex = prevLogIndex;
  53         this.prevLogTerm = prevLogTerm;
  54         this.entries = entries;
  55         this.leaderCommit = leaderCommit;
  56         this.replicatedToAllIndex = replicatedToAllIndex;
  57         this.payloadVersion = payloadVersion;
  58     }
  59
  60     public String getLeaderId() {
  61         return leaderId;
  62     }
  63
  64     public long getPrevLogIndex() {
  65         return prevLogIndex;
  66     }
  67
  68     public long getPrevLogTerm() {
  69         return prevLogTerm;
  70     }
  71
  72     public List<ReplicatedLogEntry> getEntries() {
  73         return entries;
  74     }
  75
  76     public long getLeaderCommit() {
  77         return leaderCommit;
  78     }
  79
  80     public long getReplicatedToAllIndex() {
  81         return replicatedToAllIndex;
  82     }
  83
  84     public short getPayloadVersion() {
  85         return payloadVersion;
  86     }
  87
  88     @Override
  89     public String toString() {
  90         StringBuilder builder = new StringBuilder();
  91         builder.append("AppendEntries [leaderId=").append(leaderId).append(", prevLogIndex=").append(prevLogIndex)
  92                 .append(", prevLogTerm=").append(prevLogTerm).append(", leaderCommit=").append(leaderCommit)
  93                 .append(", replicatedToAllIndex=").append(replicatedToAllIndex).append(", payloadVersion=")
  94                 .append(payloadVersion).append(", entries=").append(entries).append("]");
  95         return builder.toString();
  96     }
  97
  98     private Object writeReplace() {
  99         return new Proxy(this);
 100     }
 101
 102     private static class Proxy implements Externalizable {
 103         private static final long serialVersionUID = 1L;
 104
 105         private AppendEntries appendEntries;
 106
 107         // checkstyle flags the public modifier as redundant which really doesn't make sense since it clearly isn't
 108         // redundant. It is explicitly needed for Java serialization to be able to create instances via reflection.
 109         @SuppressWarnings("checkstyle:RedundantModifier")
 110         public Proxy() {
 111         }
 112
 113         Proxy(AppendEntries appendEntries) {
 114             this.appendEntries = appendEntries;
 115         }
 116
 117         @Override
 118         public void writeExternal(ObjectOutput out) throws IOException {
 119             out.writeLong(appendEntries.getTerm());
 120             out.writeObject(appendEntries.leaderId);
 121             out.writeLong(appendEntries.prevLogTerm);
 122             out.writeLong(appendEntries.prevLogIndex);
 123             out.writeLong(appendEntries.leaderCommit);
 124             out.writeLong(appendEntries.replicatedToAllIndex);
 125             out.writeShort(appendEntries.payloadVersion);
 126
 127             out.writeInt(appendEntries.entries.size());
 128             for (ReplicatedLogEntry e: appendEntries.entries) {
 129                 out.writeLong(e.getIndex());
 130                 out.writeLong(e.getTerm());
 131                 out.writeObject(e.getData());
 132             }
 133         }
 134
 135         @Override
 136         public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException {
 137             long term = in.readLong();
 138             String leaderId = (String) in.readObject();
 139             long prevLogTerm = in.readLong();
 140             long prevLogIndex = in.readLong();
 141             long leaderCommit = in.readLong();
 142             long replicatedToAllIndex = in.readLong();
 143             short payloadVersion = in.readShort();
 144
 145             int size = in.readInt();
 146             List<ReplicatedLogEntry> entries = new ArrayList<>(size);
 147             for (int i = 0; i < size; i++) {
 148                 entries.add(new SimpleReplicatedLogEntry(in.readLong(), in.readLong(), (Payload) in.readObject()));
 149             }
 150
 151             appendEntries = new AppendEntries(term, leaderId, prevLogIndex, prevLogTerm, entries, leaderCommit,
 152                     replicatedToAllIndex, payloadVersion);
 153         }
 154
 155         private Object readResolve() {
 156             return appendEntries;
 157         }
 158     }
 159 }