Changed DataSet merge retention policy: last timestamp wins (#110)

dz3-model/src/main/java/net/sf/dz3/controller/DataSet.java

@@ -120,18 +120,16 @@ public final synchronized void record(final long millis, final T value, boolean
 
         if (lastValue != null && merge && lastValue.equals(value)) {
 
-            // Skip this one, we already have it
-            //LogManager.getLogger(getClass()).error("dupe: " + value);
+            // Will replace it with the same value and new timestamp right below. Slower on
+            // the way in, faster on the way out.
 
-        } else {
-
-            //LogManager.getLogger(getClass()).error("take: " + value);
-
-            dataSet.put(Long.valueOf(millis), value);
-            lastValue = value;
-            lastTimestamp = millis;
+            dataSet.remove(lastTimestamp);
         }
 
+        dataSet.put(Long.valueOf(millis), value);
+        lastValue = value;
+        lastTimestamp = millis;
+
         expire();
     }
 

dz3-model/src/test/java/net/sf/dz3/controller/DataSetTest.java

@@ -43,14 +43,11 @@ public void mergeExpire() {
 
         assertEquals("wrong data set size", 1, ds.size());
 
-        // This one blows the old one past expiration, but nothing will happen
-        // because new timestamp will not be recorded
+        // This one blows the old one past expiration
 
         ds.record(200, 1.0, true);
 
-        // The very first timestamp will be still retained
-
-        assertEquals("Wrong value after expiration", 1, ds.iterator().next().longValue());
+        assertEquals("Wrong value after expiration", 200, ds.iterator().next().longValue());
         assertEquals("Wrong data set size", 1, ds.size());
     }