Fix TPStatistic hashcode to use the name instead of the type as it is the only dynamic statistic. (#97)

Author: vjkoskela

src/main/java/com/arpnetworking/tsdcore/statistics/BaseStatistic.java

@@ -16,6 +16,8 @@
 package com.arpnetworking.tsdcore.statistics;
 
 import com.google.common.base.MoreObjects;
+import com.google.common.base.Supplier;
+import com.google.common.base.Suppliers;
 
 import java.util.Collections;
 import java.util.Set;
@@ -39,7 +41,7 @@ public Set<Statistic> getDependencies() {
 
     @Override
     public int hashCode() {
-        return getClass().hashCode();
+        return _hashCodeSupplier.get();
     }
 
     @Override
@@ -57,5 +59,7 @@ public String toString() {
                 .toString();
     }
 
+    private final Supplier<Integer> _hashCodeSupplier = Suppliers.memoize(() -> getClass().hashCode());
+
     private static final long serialVersionUID = -1334453626232464982L;
 }

src/main/java/com/arpnetworking/tsdcore/statistics/TPStatistic.java

@@ -84,6 +84,23 @@ public Quantity calculateAggregations(final List<AggregatedData> aggregations) {
         return allSamples.get(index);
     }
 
+    @Override
+    public int hashCode() {
+        return getName().hashCode();
+    }
+
+    @Override
+    public boolean equals(final Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (!(o instanceof TPStatistic)) {
+            return false;
+        }
+        final TPStatistic otherTPStatistic = (TPStatistic) o;
+        return getName().equals(otherTPStatistic.getName());
+    }
+
     /**
      * Public constructor.
      *