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

   1 /*
   2  * Copyright (c) 2022 PANTHEON.tech, s.r.o. 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 package org.opendaylight.controller.cluster.raft.messages;
   9
  10 import static com.google.common.base.Verify.verifyNotNull;
  11 import static java.util.Objects.requireNonNull;
  12
  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.RaftVersions;
  18 import org.opendaylight.yangtools.concepts.WritableObjects;
  19
  20 /**
  21  * Serialization proxy for {@link AppendEntriesReply}.
  22  */
  23 final class AR implements Externalizable {
  24     @java.io.Serial
  25     private static final long serialVersionUID = 1L;
  26
  27     // Flag bits
  28     private static final int SUCCESS                = 0x10;
  29     private static final int FORCE_INSTALL_SNAPSHOT = 0x20;
  30     private static final int NEEDS_LEADER_ADDRESS   = 0x40;
  31
  32     private AppendEntriesReply appendEntriesReply;
  33
  34     @SuppressWarnings("checkstyle:RedundantModifier")
  35     public AR() {
  36         // For Externalizable
  37     }
  38
  39     AR(final AppendEntriesReply appendEntriesReply) {
  40         this.appendEntriesReply = requireNonNull(appendEntriesReply);
  41     }
  42
  43     @Override
  44     public void writeExternal(final ObjectOutput out) throws IOException {
  45         out.writeShort(appendEntriesReply.getRaftVersion());
  46
  47         int flags = 0;
  48         if (appendEntriesReply.isSuccess()) {
  49             flags |= SUCCESS;
  50         }
  51         if (appendEntriesReply.isForceInstallSnapshot()) {
  52             flags |= FORCE_INSTALL_SNAPSHOT;
  53         }
  54         if (appendEntriesReply.isNeedsLeaderAddress()) {
  55             flags |= NEEDS_LEADER_ADDRESS;
  56         }
  57         WritableObjects.writeLong(out, appendEntriesReply.getTerm(), flags);
  58
  59         out.writeObject(appendEntriesReply.getFollowerId());
  60
  61         WritableObjects.writeLongs(out, appendEntriesReply.getLogLastIndex(), appendEntriesReply.getLogLastTerm());
  62
  63         out.writeShort(appendEntriesReply.getPayloadVersion());
  64     }
  65
  66     @Override
  67     public void readExternal(final ObjectInput in) throws IOException, ClassNotFoundException {
  68         short raftVersion = in.readShort();
  69
  70         byte hdr = WritableObjects.readLongHeader(in);
  71         final int flags = WritableObjects.longHeaderFlags(hdr);
  72
  73         long term = WritableObjects.readLongBody(in, hdr);
  74         String followerId = (String) in.readObject();
  75
  76         hdr = WritableObjects.readLongHeader(in);
  77         long logLastIndex = WritableObjects.readFirstLong(in, hdr);
  78         long logLastTerm = WritableObjects.readSecondLong(in, hdr);
  79
  80         short payloadVersion = in.readShort();
  81
  82         appendEntriesReply = new AppendEntriesReply(followerId, term, getFlag(flags, SUCCESS), logLastIndex,
  83             logLastTerm, payloadVersion, getFlag(flags, FORCE_INSTALL_SNAPSHOT), getFlag(flags, NEEDS_LEADER_ADDRESS),
  84             raftVersion, RaftVersions.CURRENT_VERSION);
  85     }
  86
  87     @java.io.Serial
  88     private Object readResolve() {
  89         return verifyNotNull(appendEntriesReply);
  90     }
  91
  92     private static boolean getFlag(final int flags, final int bit) {
  93         return (flags & bit) != 0;
  94     }
  95 }