all protocol classnames now have a VS prefix

1 files changed, 200 insertions, 0 deletions

diff --git a/sources/protocols/implementations/VSBerkelyTimeProtocol.java b/sources/protocols/implementations/VSBerkelyTimeProtocol.java
new file mode 100644
index 0000000..1f13cbc
--- /dev/null
+++ b/sources/protocols/implementations/VSBerkelyTimeProtocol.java
@@ -0,0 +1,200 @@
+/*
+ * VS is (c) 2008 by Paul C. Buetow
+ * vs@dev.buetow.org
+ */
+package protocols.implementations;
+
+import protocols.VSAbstractProtocol;
+import core.VSMessage;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.Vector;
+
+/**
+ * The Class VSBerkelyTimeProtocol.
+ */
+public class VSBerkelyTimeProtocol extends VSAbstractProtocol {
+    private static final long serialVersionUID = 1L;
+
+    /**
+     * Instantiates a new berkely time protocol.
+     */
+    public VSBerkelyTimeProtocol() {
+        super(VSAbstractProtocol.HAS_ON_SERVER_START);
+        setClassname(getClass().toString());
+    }
+
+    /** Integer: Process ID, Long: Local time of the process */
+    private HashMap<Integer,Long> processTimes = new HashMap<Integer,Long>();
+
+    /** Integer: Process ID, Long: Time of receiving the response from the process */
+    private HashMap<Integer,Long> recvTimes = new HashMap<Integer,Long>();
+
+    /** Integer: Process ID, Long: Calculated process times (using the RTT) */
+    private HashMap<Integer,Long> realTimesRTT = new HashMap<Integer,Long>();
+
+    /** Contains all process IDs of processes which want to justify their time */
+    private ArrayList<Integer> peers = new ArrayList<Integer>();
+
+    /** Time the request/response has started */
+    private long requestTime;
+
+    /* (non-Javadoc)
+     * @see events.VSAbstractProtocol#onServerInit()
+     */
+    public void onServerInit() {
+        /* Those prefs are editable through the VSAbstractProtocol VSAbstractEditor GUI. */
+        Vector<Integer> vec = new Vector<Integer>();
+        vec.add(2);
+        vec.add(3);
+        initVector("pids", vec, "PIDs beteiliger Prozesse");
+    }
+
+    /* (non-Javadoc)
+     * @see protocols.VSAbstractProtocol#onServerReset()
+     */
+    public void onServerReset() {
+        processTimes.clear();
+        recvTimes.clear();
+        realTimesRTT.clear();
+        peers.clear();
+        peers.addAll(getVector("pids"));
+    }
+
+    /* (non-Javadoc)
+     * @see protocols.VSAbstractProtocol#onServerStart()
+     */
+    public void onServerStart() {
+        peers.addAll(getVector("pids"));
+        requestTime = process.getTime();
+        VSMessage message = new VSMessage();
+        message.setBoolean("isRequest", true);
+        sendMessage(message);
+    }
+
+    /* (non-Javadoc)
+     * @see protocols.VSAbstractProtocol#onServerRecv(core.VSMessage)
+     */
+    public void onServerRecv(VSMessage recvMessage) {
+        /* Ignore all protocol messages which are not a response message, e.g. itself */
+        if (!recvMessage.getBoolean("isResponse"))
+            return;
+
+        Integer processID = recvMessage.getIntegerObj("processID");
+
+        if (peers.contains(processID))
+            peers.remove(processID);
+        else
+            return; /* Process has been handled already or is not listed */
+
+        Long time = new Long(recvMessage.getLong("time"));
+
+        processTimes.put(processID, time);
+        recvTimes.put(processID, new Long(process.getTime()));
+
+        /* All peers have told their times */
+        if (peers.size() == 0) {
+            long avgTime = calculateAverageTime();
+            /* Set the local's process time to the new avg reference time */
+            process.setTime(avgTime);
+            /* Tell all other processes what to do in order to justify their times */
+            sendJustifyRequests(avgTime);
+            /* Start "clean" next time */
+            onServerReset();
+        }
+    }
+
+    /* (non-Javadoc)
+     * @see protocols.VSAbstractProtocol#onServerSchedule()
+     */
+    public void onServerSchedule() {
+    }
+
+    /**
+     * Calculate the new average time.
+     *
+     * @return the long
+     */
+    private long calculateAverageTime() {
+        long sum = 0;
+        for (Integer processID : processTimes.keySet()) {
+            Long localTime = processTimes.get(processID);
+            Long recvTime = recvTimes.get(processID);
+            long rtt = recvTime.longValue() - requestTime;
+            long realProcessTime = localTime + (long) (rtt / 2);
+            realTimesRTT.put(processID, new Long(realProcessTime));
+            sum += realProcessTime;
+        }
+        /* Include the time of the local process */
+        sum += process.getTime();
+        return (long) sum / (getVector("pids").size() + 1);
+    }
+
+    /**
+     * Sends to all clients a value to justify their local clocks.
+     *
+     * @param avgTime the avg time
+     */
+    private void sendJustifyRequests(long avgTime) {
+        for (Integer processID : processTimes.keySet()) {
+            long realProcessTime = realTimesRTT.get(processID).longValue();
+            long diff = avgTime - realProcessTime;
+            VSMessage message = new VSMessage();
+            message.setBoolean("isJustify", true);
+            message.setLong("timeDiff", diff);
+            message.setInteger("receiverProcessID", processID);
+            sendMessage(message);
+        }
+    }
+
+    /* (non-Javadoc)
+     * @see events.VSAbstractProtocol#onClientInit()
+     */
+    public void onClientInit() {
+    }
+
+    /* (non-Javadoc)
+     * @see protocols.VSAbstractProtocol#onClientReset()
+     */
+    public void onClientReset() {
+    }
+
+    /* (non-Javadoc)
+     * @see protocols.VSAbstractProtocol#onClientRecv(core.VSMessage)
+     */
+    public void onClientRecv(VSMessage recvMessage) {
+        if (recvMessage.getBoolean("isRequest")) {
+            VSMessage message = new VSMessage();
+            message.setInteger("processID", process.getProcessID());
+            message.setLong("time", process.getTime());
+            message.setBoolean("isResponse", true);
+            sendMessage(message);
+
+        } else if (recvMessage.getBoolean("isJustify")) {
+            /* Check if it's "my" justify message */
+            if (recvMessage.getInteger("receiverProcessID") != process.getProcessID())
+                return;
+
+            long timeDiff = recvMessage.getLong("timeDiff");
+            long recvTime = process.getTime();
+            long newTime = process.getTime() + timeDiff;
+            logg("Neue Zeit: " + newTime);
+
+            process.setTime(newTime);
+        }
+    }
+
+    /* (non-Javadoc)
+     * @see protocols.VSAbstractProtocol#onClientSchedule()
+     */
+    public void onClientSchedule() {
+    }
+
+    /* (non-Javadoc)
+     * @see protocols.VSAbstractProtocol#toString()
+     */
+    public String toString() {
+        return super.toString();
+    }
+}