Make View's lists of aggregations immutable.

2 files changed, 10 insertions, 3 deletions

diff --git a/core/src/main/java/com/google/instrumentation/stats/View.java b/core/src/main/java/com/google/instrumentation/stats/View.java
index 90996960..30443338 100644
--- a/core/src/main/java/com/google/instrumentation/stats/View.java
+++ b/core/src/main/java/com/google/instrumentation/stats/View.java
@@ -18,6 +18,8 @@ import com.google.instrumentation.common.Timestamp;
 import com.google.instrumentation.stats.ViewDescriptor.DistributionViewDescriptor;
 import com.google.instrumentation.stats.ViewDescriptor.IntervalViewDescriptor;
 
+import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 
 /**
@@ -96,7 +98,9 @@ public abstract class View {
     private DistributionView(DistributionViewDescriptor distributionViewDescriptor,
         List<DistributionAggregation> distributionAggregations, Timestamp start, Timestamp end) {
       this.distributionViewDescriptor = distributionViewDescriptor;
-      this.distributionAggregations = distributionAggregations;
+      this.distributionAggregations =
+          Collections.unmodifiableList(
+              new ArrayList<DistributionAggregation>(distributionAggregations));
       this.start = start;
       this.end = end;
     }
@@ -142,7 +146,8 @@ public abstract class View {
     private IntervalView(IntervalViewDescriptor intervalViewDescriptor,
         List<IntervalAggregation> intervalAggregations) {
       this.intervalViewDescriptor = intervalViewDescriptor;
-      this.intervalAggregations = intervalAggregations;
+      this.intervalAggregations =
+          Collections.unmodifiableList(new ArrayList<IntervalAggregation>(intervalAggregations));
     }
   }
 }
diff --git a/core_impl/src/test/java/com/google/instrumentation/stats/StatsManagerImplTest.java b/core_impl/src/test/java/com/google/instrumentation/stats/StatsManagerImplTest.java
index 396f43ce..2e2beb54 100644
--- a/core_impl/src/test/java/com/google/instrumentation/stats/StatsManagerImplTest.java
+++ b/core_impl/src/test/java/com/google/instrumentation/stats/StatsManagerImplTest.java
@@ -20,6 +20,7 @@ import com.google.instrumentation.common.SimpleEventQueue;
 import com.google.instrumentation.common.Timestamp;
 import com.google.instrumentation.internal.TestClock;
 import com.google.instrumentation.stats.View.DistributionView;
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.Comparator;
@@ -127,7 +128,8 @@ public class StatsManagerImplTest {
 
     DistributionView view =
         (DistributionView) statsManager.getView(RpcViewConstants.RPC_CLIENT_ROUNDTRIP_LATENCY_VIEW);
-    List<DistributionAggregation> distributionAggregations = view.getDistributionAggregations();
+    List<DistributionAggregation> distributionAggregations =
+        new ArrayList<DistributionAggregation>(view.getDistributionAggregations());
     assertThat(distributionAggregations).hasSize(2);
     // Sort distributionAggregations by count.
     Collections.sort(distributionAggregations, new Comparator<DistributionAggregation>() {