From 4b3cc8e126dc12b188ca7af8600a0ca02d4484fe Mon Sep 17 00:00:00 2001
From: Connor Taylor-Brown <cbt24@uclive.ac.nz>
Date: Thu, 17 Aug 2017 11:47:54 +1200
Subject: [PATCH] Created ack number generator for use by multiple services

#story[1100]
---
 .../java/mock/app/ConnectionAcceptor.java     | 19 ++---------------
 .../src/main/java/mock/model/RaceServer.java  |  1 -
 .../src/main/java/network/AckSequencer.java   | 21 +++++++++++++++++++
 3 files changed, 23 insertions(+), 18 deletions(-)
 create mode 100644 racevisionGame/src/main/java/network/AckSequencer.java

diff --git a/racevisionGame/src/main/java/mock/app/ConnectionAcceptor.java b/racevisionGame/src/main/java/mock/app/ConnectionAcceptor.java
index d399210d..da5c50f8 100644
--- a/racevisionGame/src/main/java/mock/app/ConnectionAcceptor.java
+++ b/racevisionGame/src/main/java/mock/app/ConnectionAcceptor.java
@@ -4,6 +4,7 @@ import mock.model.RaceLogic;
 import mock.model.ClientConnection;
 import mock.model.SourceIdAllocator;
 import mock.model.commandFactory.CompositeCommand;
+import network.AckSequencer;
 import network.Messages.Enums.XMLMessageType;
 import network.Messages.LatestMessages;
 import network.Messages.XMLMessage;
@@ -58,11 +59,6 @@ public class ConnectionAcceptor implements Runnable {
      */
     private SourceIdAllocator sourceIdAllocator;
 
-
-
-
-    //Acknowledgement number for packets
-    private int ackNumber = 0;
     //race xml sequence number
     private short raceXMLSequenceNumber;
     //boat xml sequence number
@@ -263,7 +259,7 @@ public class ConnectionAcceptor implements Runnable {
         //Create the message.
         XMLMessage message = new XMLMessage(
                 XMLMessage.currentVersionNumber,
-                getNextAckNumber(),
+                AckSequencer.getNextAckNum(),
                 System.currentTimeMillis(),
                 messageType,
                 sequenceNumber,
@@ -272,15 +268,4 @@ public class ConnectionAcceptor implements Runnable {
 
         return message;
     }
-
-    /**
-     * Increments the ackNumber value, and returns it.
-     * @return Incremented ackNumber.
-     */
-    private int getNextAckNumber(){
-        this.ackNumber++;
-
-        return this.ackNumber;
-    }
-
 }
diff --git a/racevisionGame/src/main/java/mock/model/RaceServer.java b/racevisionGame/src/main/java/mock/model/RaceServer.java
index af343666..cbbe1971 100644
--- a/racevisionGame/src/main/java/mock/model/RaceServer.java
+++ b/racevisionGame/src/main/java/mock/model/RaceServer.java
@@ -28,7 +28,6 @@ public class RaceServer {
         this.latestMessages = latestMessages;
     }
 
-
     /**
      * Parses the race to create a snapshot, and places it in latestMessages.
      */
diff --git a/racevisionGame/src/main/java/network/AckSequencer.java b/racevisionGame/src/main/java/network/AckSequencer.java
new file mode 100644
index 00000000..bed59664
--- /dev/null
+++ b/racevisionGame/src/main/java/network/AckSequencer.java
@@ -0,0 +1,21 @@
+package network;
+
+import java.util.concurrent.atomic.AtomicInteger;
+
+/**
+ * Common source of ack numbers for all messages
+ */
+public class AckSequencer {
+    /**
+     * Generator for ack numbers
+     */
+    private static AtomicInteger ackNum = new AtomicInteger(0);
+
+    /**
+     * Retrieve next ack number
+     * @return next ack number
+     */
+    public static int getNextAckNum() {
+        return ackNum.getAndIncrement();
+    }
+}