opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/messages/InstallSnapshot.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.common.base.Optional;
  12 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
  13 import java.io.Externalizable;
  14 import java.io.IOException;
  15 import java.io.ObjectInput;
  16 import java.io.ObjectOutput;
  17 import org.opendaylight.controller.cluster.raft.persisted.ServerConfigurationPayload;
  18
  19 /**
  20  * Message sent from a leader to install a snapshot chunk on a follower.
  21  */
  22 public class InstallSnapshot extends AbstractRaftRPC {
  23     private static final long serialVersionUID = 1L;
  24
  25     private final String leaderId;
  26     private final long lastIncludedIndex;
  27     private final long lastIncludedTerm;
  28     private final byte[] data;
  29     private final int chunkIndex;
  30     private final int totalChunks;
  31     private final Optional<Integer> lastChunkHashCode;
  32     private final Optional<ServerConfigurationPayload> serverConfig;
  33
  34     @SuppressFBWarnings(value = "EI_EXPOSE_REP2", justification = "Stores a reference to an externally mutable byte[] "
  35             + "object but this is OK since this class is merely a DTO and does not process byte[] internally. "
  36             + "Also it would be inefficient to create a copy as the byte[] could be large.")
  37     public InstallSnapshot(long term, String leaderId, long lastIncludedIndex, long lastIncludedTerm, byte[] data,
  38             int chunkIndex, int totalChunks, Optional<Integer> lastChunkHashCode,
  39             Optional<ServerConfigurationPayload> serverConfig) {
  40         super(term);
  41         this.leaderId = leaderId;
  42         this.lastIncludedIndex = lastIncludedIndex;
  43         this.lastIncludedTerm = lastIncludedTerm;
  44         this.data = data;
  45         this.chunkIndex = chunkIndex;
  46         this.totalChunks = totalChunks;
  47         this.lastChunkHashCode = lastChunkHashCode;
  48         this.serverConfig = serverConfig;
  49     }
  50
  51     public InstallSnapshot(long term, String leaderId, long lastIncludedIndex,
  52                            long lastIncludedTerm, byte[] data, int chunkIndex, int totalChunks) {
  53         this(term, leaderId, lastIncludedIndex, lastIncludedTerm, data, chunkIndex, totalChunks,
  54                 Optional.<Integer>absent(), Optional.<ServerConfigurationPayload>absent());
  55     }
  56
  57     public String getLeaderId() {
  58         return leaderId;
  59     }
  60
  61     public long getLastIncludedIndex() {
  62         return lastIncludedIndex;
  63     }
  64
  65     public long getLastIncludedTerm() {
  66         return lastIncludedTerm;
  67     }
  68
  69     @SuppressFBWarnings(value = "EI_EXPOSE_REP", justification = "Exposes a mutable object stored in a field but "
  70             + "this is OK since this class is merely a DTO and does not process the byte[] internally. "
  71             + "Also it would be inefficient to create a return copy as the byte[] could be large.")
  72     public byte[] getData() {
  73         return data;
  74     }
  75
  76     public int getChunkIndex() {
  77         return chunkIndex;
  78     }
  79
  80     public int getTotalChunks() {
  81         return totalChunks;
  82     }
  83
  84     public Optional<Integer> getLastChunkHashCode() {
  85         return lastChunkHashCode;
  86     }
  87
  88     public Optional<ServerConfigurationPayload> getServerConfig() {
  89         return serverConfig;
  90     }
  91
  92
  93     public <T> Object toSerializable(short version) {
  94         return this;
  95     }
  96
  97     @Override
  98     public String toString() {
  99         return "InstallSnapshot [term=" + getTerm() + ", leaderId=" + leaderId + ", lastIncludedIndex="
 100                 + lastIncludedIndex + ", lastIncludedTerm=" + lastIncludedTerm + ", datasize=" + data.length
 101                 + ", Chunk=" + chunkIndex + "/" + totalChunks + ", lastChunkHashCode=" + lastChunkHashCode
 102                 + ", serverConfig=" + serverConfig.orNull() + "]";
 103     }
 104
 105     private Object writeReplace() {
 106         return new Proxy(this);
 107     }
 108
 109     private static class Proxy implements Externalizable {
 110         private static final long serialVersionUID = 1L;
 111
 112         private InstallSnapshot installSnapshot;
 113
 114         // checkstyle flags the public modifier as redundant which really doesn't make sense since it clearly isn't
 115         // redundant. It is explicitly needed for Java serialization to be able to create instances via reflection.
 116         @SuppressWarnings("checkstyle:RedundantModifier")
 117         public Proxy() {
 118         }
 119
 120         Proxy(InstallSnapshot installSnapshot) {
 121             this.installSnapshot = installSnapshot;
 122         }
 123
 124         @Override
 125         public void writeExternal(ObjectOutput out) throws IOException {
 126             out.writeLong(installSnapshot.getTerm());
 127             out.writeObject(installSnapshot.leaderId);
 128             out.writeLong(installSnapshot.lastIncludedIndex);
 129             out.writeLong(installSnapshot.lastIncludedTerm);
 130             out.writeInt(installSnapshot.chunkIndex);
 131             out.writeInt(installSnapshot.totalChunks);
 132
 133             out.writeByte(installSnapshot.lastChunkHashCode.isPresent() ? 1 : 0);
 134             if (installSnapshot.lastChunkHashCode.isPresent()) {
 135                 out.writeInt(installSnapshot.lastChunkHashCode.get().intValue());
 136             }
 137
 138             out.writeByte(installSnapshot.serverConfig.isPresent() ? 1 : 0);
 139             if (installSnapshot.serverConfig.isPresent()) {
 140                 out.writeObject(installSnapshot.serverConfig.get());
 141             }
 142
 143             out.writeObject(installSnapshot.data);
 144         }
 145
 146         @Override
 147         public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException {
 148             long term = in.readLong();
 149             String leaderId = (String) in.readObject();
 150             long lastIncludedIndex = in.readLong();
 151             long lastIncludedTerm = in.readLong();
 152             int chunkIndex = in.readInt();
 153             int totalChunks = in.readInt();
 154
 155             Optional<Integer> lastChunkHashCode = Optional.absent();
 156             boolean chunkHashCodePresent = in.readByte() == 1;
 157             if (chunkHashCodePresent) {
 158                 lastChunkHashCode = Optional.of(in.readInt());
 159             }
 160
 161             Optional<ServerConfigurationPayload> serverConfig = Optional.absent();
 162             boolean serverConfigPresent = in.readByte() == 1;
 163             if (serverConfigPresent) {
 164                 serverConfig = Optional.of((ServerConfigurationPayload)in.readObject());
 165             }
 166
 167             byte[] data = (byte[])in.readObject();
 168
 169             installSnapshot = new InstallSnapshot(term, leaderId, lastIncludedIndex, lastIncludedTerm, data,
 170                     chunkIndex, totalChunks, lastChunkHashCode, serverConfig);
 171         }
 172
 173         private Object readResolve() {
 174             return installSnapshot;
 175         }
 176     }
 177 }