the stream receiver can now be passed a threadsafe priorityQueue that it will add the packets to as they are received (note the priority queue passed should be initialized with a comparitor for "StreamPacket"s) #story[817]

src/main/java/seng302/models/parsers/StreamPacket.java

@@ -22,4 +22,8 @@ public class StreamPacket {
             StreamParser.extractBoatLocation(payload);
         }
     }
+
+    public long getTimeStamp() {
+        return timeStamp;
+    }
 }

src/main/java/seng302/models/parsers/StreamParser.java

@@ -53,10 +53,10 @@ public class StreamParser {
         byte[] boatIdBytes = Arrays.copyOfRange(payload,8,12);
         extractTimeStamp(Arrays.copyOfRange(payload,1,7));
 //        int boatSeq =  ByteBuffer.wrap(seqBytes).getInt();
-        long seq = StreamReceiver.bytesToLong(seqBytes);
-        long boatId = StreamReceiver.bytesToLong(boatIdBytes);
-        long lat = StreamReceiver.bytesToLong(latBytes);
-        long lon = StreamReceiver.bytesToLong(lonBytes);
+        long seq = bytesToLong(seqBytes);
+        long boatId = bytesToLong(boatIdBytes);
+        long lat = bytesToLong(latBytes);
+        long lon = bytesToLong(lonBytes);
         if (!ids.contains(boatId)) {
             ids.add(boatId);
         }
@@ -81,6 +81,23 @@ public class StreamParser {
         System.out.println("timeStamp = " + timeStamp);
     }
 
-
+    /**
+     * takes an array of up to 7 bytes and returns a positive
+     * long constructed from the input bytes
+     *
+     * @return a positive long if there is less than 7 bytes -1 otherwise
+     */
+    private static long bytesToLong(byte[] bytes){
+        long partialLong = 0;
+        int index = 0;
+        for (byte b: bytes){
+            if (index > 6){
+                return -1;
+            }
+            partialLong = partialLong | (b & 0xFFL) << (index * 8);
+            index++;
+        }
+        return partialLong;
+    }
 }
 

src/main/java/seng302/models/parsers/StreamReceiver.java

@@ -47,22 +47,20 @@ public class StreamReceiver {
                 //checking if it is the start of the packet
                 if(sync1 == 0x47 && sync2 == 0x83) {
                     int type = readByte();
-                    System.out.println("message type: " + type);
                     long timeStamp = bytesToLong(getBytes(6));
                     skipBytes(4);
                     long payloadLength = bytesToLong(getBytes(2));
                     //No. of milliseconds since Jan 1st 1970
-                    System.out.println("timeStamp = " + timeStamp);
-                    System.out.println("payload length: " + payloadLength);
-
-
+                    byte[] payload = getBytes((int) payloadLength);
                     Checksum checksum = new CRC32();
                     checksum.update(crcBuffer.toByteArray(), 0, crcBuffer.size());
-//                System.out.println(checksum.getValue());
-                    long crc = bytesToLong(getBytes(4));
-//                System.out.println(crc);
-                    if (checksum.getValue() == crc) {
-                        packetBuffer.add(new StreamPacket(type, payloadLength, timeStamp, getBytes((int) payloadLength)));
+                    long computedCrc = checksum.getValue();
+                    long packetCrc = bytesToLong(getBytes(4));
+                    if (computedCrc == packetCrc) {
+                        System.out.println("message type: " + type);
+                        System.out.println("timeStamp = " + timeStamp);
+                        System.out.println("payload length: " + payloadLength);
+                        packetBuffer.add(new StreamPacket(type, payloadLength, timeStamp, payload));
                     } else {
                         System.err.println("Packet has been dropped");
                     }
@@ -74,20 +72,21 @@ public class StreamReceiver {
         }
     }
 
-    private int readByte() {
+    private int readByte() throws Exception {
         int currentByte = -1;
         try {
             currentByte = stream.read();
             crcBuffer.write(currentByte);
-            if (currentByte == -1){
-            }
         } catch (IOException e) {
             e.printStackTrace();
         }
+        if (currentByte == -1){
+            throw new Exception();
+        }
         return currentByte;
     }
 
-    private byte[] getBytes(int n){
+    private byte[] getBytes(int n) throws Exception{
         byte[] bytes = new byte[n];
         for (int i = 0; i < n; i++){
             bytes[i] = (byte) readByte();
@@ -96,7 +95,7 @@ public class StreamReceiver {
     }
 
 
-    private void skipBytes(long n){
+    private void skipBytes(long n) throws Exception{
         for (int i=0; i < n; i++){
             readByte();
         }
@@ -123,7 +122,13 @@ public class StreamReceiver {
 
 
     public static void main(String[] args) {
-//        StreamReceiver sr = new StreamReceiver("livedata.americascup.com", 4941, pq);
-//        sr.connect();
+        PriorityBlockingQueue<StreamPacket> pq = new PriorityBlockingQueue<>(256, new Comparator<StreamPacket>() {
+            @Override
+            public int compare(StreamPacket s1, StreamPacket s2) {
+                return (int) (s1.getTimeStamp() - s2.getTimeStamp());
+            }
+        });
+        StreamReceiver sr = new StreamReceiver("livedata.americascup.com", 4941, pq);
+        sr.connect();
     }
 }