Add initial Raft protocol skeleton for bc61c489-f41b-473b-8c9b-91959ad958f7

2 files changed, 140 insertions, 0 deletions

diff --git a/src/main/java/events/VSRegisteredEvents.java b/src/main/java/events/VSRegisteredEvents.java
index 92deeb0..8d31b0e 100644
--- a/src/main/java/events/VSRegisteredEvents.java
+++ b/src/main/java/events/VSRegisteredEvents.java
@@ -96,6 +96,7 @@ public final class VSRegisteredEvents {
         registerEvent("protocols.implementations.VSInternalTimeSyncProtocol");
         registerEvent("protocols.implementations.VSOnePhaseCommitProtocol");
         registerEvent("protocols.implementations.VSPingPongProtocol");
+        registerEvent("protocols.implementations.VSRaftProtocol");
         registerEvent("protocols.implementations.VSReliableMulticastProtocol");
         registerEvent("protocols.implementations.VSTwoPhaseCommitProtocol");
         registerEvent("protocols.implementations.VSTimestampDemoProtocol");
diff --git a/src/main/java/protocols/implementations/VSRaftProtocol.java b/src/main/java/protocols/implementations/VSRaftProtocol.java
new file mode 100644
index 0000000..8b919f6
--- /dev/null
+++ b/src/main/java/protocols/implementations/VSRaftProtocol.java
@@ -0,0 +1,139 @@
+package protocols.implementations;
+
+import java.util.ArrayList;
+import java.util.Vector;
+
+import core.VSMessage;
+import protocols.VSAbstractProtocol;
+
+/**
+ * The class VSRaftProtocol, a skeleton for a Raft-based protocol.
+ *
+ * @author Paul C. Buetow
+ */
+public class VSRaftProtocol extends VSAbstractProtocol {
+    /** The current Raft term. */
+    private int currentTerm;
+
+    /** The PID voted for in the current term. */
+    private int votedFor;
+
+    /** The number of votes received while acting as a candidate. */
+    private int votesReceived;
+
+    /** The current leader PID. */
+    private int leaderId;
+
+    /** True if this process currently acts as the leader. */
+    private boolean isLeader;
+
+    /** True if this process currently acts as a candidate. */
+    private boolean isCandidate;
+
+    /** The local time when the last heartbeat was observed. */
+    private long lastHeartbeatTime;
+
+    /** PIDs which still have to acknowledge the current operation. */
+    private ArrayList<Integer> ackPids;
+
+    /** The local log index. */
+    private int logIndex;
+
+    /** The last committed log index. */
+    private int commitIndex;
+
+    /**
+     * Instantiates a new Raft protocol skeleton.
+     */
+    public VSRaftProtocol() {
+        super(VSAbstractProtocol.HAS_ON_SERVER_START);
+        setClassname(getClass().toString());
+        resetState();
+    }
+
+    /* (non-Javadoc)
+     * @see events.VSAbstractProtocol#onServerInit()
+     */
+    public void onServerInit() {
+        Vector<Integer> vec = new Vector<Integer>();
+        vec.add(2);
+        vec.add(3);
+
+        initVector("pids", vec, "PIDs of participating follower processes");
+        initLong("heartbeatInterval", 1500, "Heartbeat interval", "ms");
+        initString("logEntry", "cmd1", "Log entry to replicate");
+    }
+
+    /* (non-Javadoc)
+     * @see events.VSAbstractProtocol#onClientInit()
+     */
+    public void onClientInit() {
+        initLong("electionTimeout", 4000, "Base election timeout", "ms");
+        initLong("electionJitter", 2000, "Election timeout jitter", "ms");
+    }
+
+    /* (non-Javadoc)
+     * @see protocols.VSAbstractProtocol#onServerStart()
+     */
+    public void onServerStart() {
+    }
+
+    /* (non-Javadoc)
+     * @see protocols.VSAbstractProtocol#onServerRecv(core.VSMessage)
+     */
+    public void onServerRecv(VSMessage recvMessage) {
+    }
+
+    /* (non-Javadoc)
+     * @see protocols.VSAbstractProtocol#onClientRecv(core.VSMessage)
+     */
+    public void onClientRecv(VSMessage recvMessage) {
+    }
+
+    /* (non-Javadoc)
+     * @see protocols.VSAbstractProtocol#onServerSchedule()
+     */
+    public void onServerSchedule() {
+    }
+
+    /* (non-Javadoc)
+     * @see protocols.VSAbstractProtocol#onClientSchedule()
+     */
+    public void onClientSchedule() {
+    }
+
+    /* (non-Javadoc)
+     * @see protocols.VSAbstractProtocol#onServerReset()
+     */
+    public void onServerReset() {
+        resetState();
+    }
+
+    /* (non-Javadoc)
+     * @see protocols.VSAbstractProtocol#onClientReset()
+     */
+    public void onClientReset() {
+        resetState();
+    }
+
+    /**
+     * Resets the shared Raft state to its initial values.
+     */
+    private void resetState() {
+        currentTerm = 0;
+        votedFor = -1;
+        votesReceived = 0;
+        leaderId = -1;
+        isLeader = false;
+        isCandidate = false;
+        lastHeartbeatTime = 0;
+        logIndex = 0;
+        commitIndex = 0;
+
+        if (ackPids == null) {
+            ackPids = new ArrayList<Integer>();
+        } else {
+            ackPids.clear();
+        }
+    }
+}