Merge pull request #123 from m-chrzan/clean_udup

Add cleaning to UDUP

1 files changed, 26 insertions, 4 deletions

diff --git a/src/main/java/pl/edu/mimuw/cloudatlas/agent/modules/UDUPServer.java b/src/main/java/pl/edu/mimuw/cloudatlas/agent/modules/UDUPServer.java
index dae0420..677bf67 100644
--- a/src/main/java/pl/edu/mimuw/cloudatlas/agent/modules/UDUPServer.java
+++ b/src/main/java/pl/edu/mimuw/cloudatlas/agent/modules/UDUPServer.java
@@ -9,9 +9,7 @@ import java.io.ByteArrayInputStream;
 import java.io.IOException;
 import java.net.*;
 import java.nio.ByteBuffer;
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.NoSuchElementException;
+import java.util.*;
 import java.util.concurrent.atomic.AtomicBoolean;
 
 public class UDUPServer implements Runnable {
@@ -20,25 +18,45 @@ public class UDUPServer implements Runnable {
     private DatagramSocket socket;
     private InetAddress address;
     private HashMap<String, ArrayList<byte[]>> partialPackets;
+    private HashMap<String, Long> partialPacketTimestamps;
     private int bufSize;
     private final AtomicBoolean running;
+    private long freshnessPeriod;
 
-    public UDUPServer(InetAddress addr, int port, int bufSize) throws SocketException {
+    public UDUPServer(InetAddress addr, int port, int bufSize, long freshnessPeriod) throws SocketException {
         this.socket = new DatagramSocket(port);
         this.address = addr;
         this.bufSize = bufSize;
         this.partialPackets = new HashMap<>();
         this.serializer = new ByteSerializer();
         this.running = new AtomicBoolean(false);
+        this.freshnessPeriod = freshnessPeriod;
+        this.partialPacketTimestamps = new HashMap<>();
     }
 
     public void setUDUP(UDUP udup) {
         this.udp = udup;
     }
 
+    private void purgeData() {
+        long currentTime = System.currentTimeMillis();
+        ArrayList<String> packetsToRemove = new ArrayList<>();
+        for (Map.Entry<String, Long> packetTimestamp : partialPacketTimestamps.entrySet()) {
+            if (packetTimestamp.getValue() + freshnessPeriod < currentTime) {
+                packetsToRemove.add(packetTimestamp.getKey());
+            }
+        }
+
+        for (String packetToRemove : packetsToRemove) {
+            partialPacketTimestamps.remove(packetToRemove);
+            partialPackets.remove(packetToRemove);
+        }
+    }
+
     public void run() {
         System.out.println("UDP server running");
         this.running.getAndSet(true);
+
         while(this.running.get()) {
             try {
                 this.acceptMessage();
@@ -71,6 +89,8 @@ public class UDUPServer implements Runnable {
             msg.getContent().setSenderAddress(packet.getAddress());
             sendMessageFurther(msg);
         }
+
+        purgeData();
     }
 
     private DatagramPacket receivePacket() throws IOException {
@@ -120,6 +140,7 @@ public class UDUPServer implements Runnable {
 
         previousPacketData.add(newPacketNo - 1, newPacketData);
         this.partialPackets.put(transmissionID, previousPacketData);
+        this.partialPacketTimestamps.put(transmissionID, System.currentTimeMillis());
 
         if (previousPacketData.contains(null)) {
             throw new NoSuchElementException("Packet is not full");
@@ -135,6 +156,7 @@ public class UDUPServer implements Runnable {
     public UDUPMessage addPartialMessageAndCheckSerialization(String transmissionID, int newPacketNo, byte[] packetData) {
         UDUPMessage msg = null;
 
+        this.partialPacketTimestamps.put(transmissionID, System.currentTimeMillis());
         if (this.partialPackets.containsKey(transmissionID)) {
             try {
                 byte[] allPacketData = concatPacketData(transmissionID, newPacketNo, packetData);