2 * Copyright (c) 2014 Cisco Systems, Inc. and others. All rights reserved.
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
8 package org.opendaylight.controller.cluster.raft.persisted;
10 import java.io.Externalizable;
11 import java.io.IOException;
12 import java.io.ObjectInput;
13 import java.io.ObjectOutput;
14 import java.io.Serializable;
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.messages.Payload;
21 * Represents a snapshot of the raft data.
23 * @author Thomas Pantelis
25 // Not final for mocking
26 public class Snapshot implements Serializable {
29 * Implementations of this interface are used as the state payload for a snapshot.
31 * @author Thomas Pantelis
33 public interface State extends Serializable {
35 * Indicate whether the snapshot requires migration, i.e. a new snapshot should be created after recovery.
36 * Default implementation returns false, i.e. do not re-snapshot.
38 * @return True if complete recovery based upon this snapshot should trigger a new snapshot.
40 default boolean needsMigration() {
45 @Deprecated(since = "7.0.0", forRemoval = true)
46 private static final class Proxy implements Externalizable {
48 private static final long serialVersionUID = 1L;
50 private Snapshot snapshot;
52 // checkstyle flags the public modifier as redundant which really doesn't make sense since it clearly isn't
53 // redundant. It is explicitly needed for Java serialization to be able to create instances via reflection.
54 @SuppressWarnings("checkstyle:RedundantModifier")
59 Proxy(final Snapshot snapshot) {
60 this.snapshot = snapshot;
64 public void writeExternal(final ObjectOutput out) throws IOException {
65 out.writeLong(snapshot.lastIndex);
66 out.writeLong(snapshot.lastTerm);
67 out.writeLong(snapshot.lastAppliedIndex);
68 out.writeLong(snapshot.lastAppliedTerm);
69 out.writeLong(snapshot.electionTerm);
70 out.writeObject(snapshot.electionVotedFor);
71 out.writeObject(snapshot.serverConfig);
73 out.writeInt(snapshot.unAppliedEntries.size());
74 for (ReplicatedLogEntry e: snapshot.unAppliedEntries) {
75 out.writeLong(e.getIndex());
76 out.writeLong(e.getTerm());
77 out.writeObject(e.getData());
80 out.writeObject(snapshot.state);
84 public void readExternal(final ObjectInput in) throws IOException, ClassNotFoundException {
85 long lastIndex = in.readLong();
86 long lastTerm = in.readLong();
87 long lastAppliedIndex = in.readLong();
88 long lastAppliedTerm = in.readLong();
89 long electionTerm = in.readLong();
90 String electionVotedFor = (String) in.readObject();
91 ServerConfigurationPayload serverConfig = (ServerConfigurationPayload) in.readObject();
93 int size = in.readInt();
94 List<ReplicatedLogEntry> unAppliedEntries = new ArrayList<>(size);
95 for (int i = 0; i < size; i++) {
96 unAppliedEntries.add(new SimpleReplicatedLogEntry(in.readLong(), in.readLong(),
97 (Payload) in.readObject()));
100 State state = (State) in.readObject();
102 snapshot = Snapshot.create(state, unAppliedEntries, lastIndex, lastTerm, lastAppliedIndex, lastAppliedTerm,
103 electionTerm, electionVotedFor, serverConfig);
107 private Object readResolve() {
113 private static final long serialVersionUID = 1L;
115 private final State state;
116 private final List<ReplicatedLogEntry> unAppliedEntries;
117 private final long lastIndex;
118 private final long lastTerm;
119 private final long lastAppliedIndex;
120 private final long lastAppliedTerm;
121 private final long electionTerm;
122 private final String electionVotedFor;
123 private final ServerConfigurationPayload serverConfig;
125 Snapshot(final State state, final List<ReplicatedLogEntry> unAppliedEntries, final long lastIndex,
126 final long lastTerm, final long lastAppliedIndex, final long lastAppliedTerm, final long electionTerm,
127 final String electionVotedFor, final ServerConfigurationPayload serverConfig) {
129 this.unAppliedEntries = unAppliedEntries;
130 this.lastIndex = lastIndex;
131 this.lastTerm = lastTerm;
132 this.lastAppliedIndex = lastAppliedIndex;
133 this.lastAppliedTerm = lastAppliedTerm;
134 this.electionTerm = electionTerm;
135 this.electionVotedFor = electionVotedFor;
136 this.serverConfig = serverConfig;
139 public static Snapshot create(final State state, final List<ReplicatedLogEntry> entries, final long lastIndex,
140 final long lastTerm, final long lastAppliedIndex, final long lastAppliedTerm, final long electionTerm,
141 final String electionVotedFor, final ServerConfigurationPayload serverConfig) {
142 return new Snapshot(state, entries, lastIndex, lastTerm, lastAppliedIndex, lastAppliedTerm,
143 electionTerm, electionVotedFor, serverConfig);
146 public State getState() {
150 public List<ReplicatedLogEntry> getUnAppliedEntries() {
151 return unAppliedEntries;
154 public long getLastTerm() {
158 public long getLastAppliedIndex() {
159 return lastAppliedIndex;
162 public long getLastAppliedTerm() {
163 return lastAppliedTerm;
166 public long getLastIndex() {
170 public long getElectionTerm() {
174 public String getElectionVotedFor() {
175 return electionVotedFor;
178 public ServerConfigurationPayload getServerConfiguration() {
183 private Object writeReplace() {
188 public String toString() {
189 return "Snapshot [lastIndex=" + lastIndex + ", lastTerm=" + lastTerm + ", lastAppliedIndex=" + lastAppliedIndex
190 + ", lastAppliedTerm=" + lastAppliedTerm + ", unAppliedEntries size=" + unAppliedEntries.size()
191 + ", state=" + state + ", electionTerm=" + electionTerm + ", electionVotedFor="
192 + electionVotedFor + ", ServerConfigPayload=" + serverConfig + "]";