[COST] Normalize the return value of ClusterCost from `HasClusterCo…

…st#of` (#1465)
opensource4you · Jan 31, 2023 · 9faa0da · 9faa0da
1 parent e253725
commit 9faa0da
Show file tree

Hide file tree

Showing 2 changed files with 3 additions and 2 deletions.
diff --git a/common/src/main/java/org/astraea/common/cost/HasClusterCost.java b/common/src/main/java/org/astraea/common/cost/HasClusterCost.java
@@ -52,9 +52,10 @@ public ClusterCost clusterCost(ClusterInfo clusterInfo, ClusterBean clusterBean)
                     Collectors.toUnmodifiableMap(
                         Map.Entry::getKey,
                         e -> e.getKey().clusterCost(clusterInfo, clusterBean).value()));
+        var totalWeight = costAndWeight.values().stream().mapToDouble(x -> x).sum();
         var compositeScore =
             costAndWeight.keySet().stream()
-                .mapToDouble(cost -> costAndWeight.get(cost) * scores.get(cost))
+                .mapToDouble(cost -> scores.get(cost) * costAndWeight.get(cost) / totalWeight)
                 .sum();
 
         return new ClusterCost() {

diff --git a/common/src/test/java/org/astraea/common/cost/ClusterCostTest.java b/common/src/test/java/org/astraea/common/cost/ClusterCostTest.java
@@ -45,7 +45,7 @@ void testMerge() {
     HasClusterCost cost2 = (c, b) -> () -> 0.8;
     var merged = HasClusterCost.of(Map.of(cost0, 1D, cost1, 2D, cost2, 2D));
     var result = merged.clusterCost(null, null).value();
-    Assertions.assertEquals(2.8, Math.round(result * 100.0) / 100.0);
+    Assertions.assertEquals(0.56, Math.round(result * 100.0) / 100.0);
   }
 
   @Test