Add BucketOptions for DistributionValue (#1484)

* Add BucketOptions for DistributionValue

* Fix reviews

2 files changed, 12 insertions, 10 deletions

diff --git a/impl_core/src/main/java/io/opencensus/implcore/stats/MutableAggregation.java b/impl_core/src/main/java/io/opencensus/implcore/stats/MutableAggregation.java
index 83beaea7..6e2bff1c 100644
--- a/impl_core/src/main/java/io/opencensus/implcore/stats/MutableAggregation.java
+++ b/impl_core/src/main/java/io/opencensus/implcore/stats/MutableAggregation.java
@@ -22,6 +22,7 @@ import static com.google.common.base.Preconditions.checkNotNull;
 import com.google.common.annotations.VisibleForTesting;
 import io.opencensus.common.Timestamp;
 import io.opencensus.metrics.export.Distribution;
+import io.opencensus.metrics.export.Distribution.BucketOptions;
 import io.opencensus.metrics.export.Point;
 import io.opencensus.metrics.export.Value;
 import io.opencensus.stats.Aggregation;
@@ -427,14 +428,15 @@ abstract class MutableAggregation {
         }
         buckets.add(metricBucket);
       }
+
+      // TODO(mayurkale): Drop the first bucket when converting to metrics.
+      // Reason: In Stats API, bucket bounds begin with -infinity (first bucket is (-infinity, 0)).
+      BucketOptions bucketOptions = BucketOptions.explicitOptions(bucketBoundaries.getBoundaries());
+
       return Point.create(
           Value.distributionValue(
               Distribution.create(
-                  count,
-                  mean * count,
-                  sumOfSquaredDeviations,
-                  bucketBoundaries.getBoundaries(),
-                  buckets)),
+                  count, mean * count, sumOfSquaredDeviations, bucketOptions, buckets)),
           timestamp);
     }
 
diff --git a/impl_core/src/test/java/io/opencensus/implcore/stats/MutableAggregationTest.java b/impl_core/src/test/java/io/opencensus/implcore/stats/MutableAggregationTest.java
index fced533f..bf76b8fb 100644
--- a/impl_core/src/test/java/io/opencensus/implcore/stats/MutableAggregationTest.java
+++ b/impl_core/src/test/java/io/opencensus/implcore/stats/MutableAggregationTest.java
@@ -30,6 +30,7 @@ import io.opencensus.implcore.stats.MutableAggregation.MutableSumDouble;
 import io.opencensus.implcore.stats.MutableAggregation.MutableSumLong;
 import io.opencensus.metrics.export.Distribution;
 import io.opencensus.metrics.export.Distribution.Bucket;
+import io.opencensus.metrics.export.Distribution.BucketOptions;
 import io.opencensus.metrics.export.Point;
 import io.opencensus.metrics.export.Value;
 import io.opencensus.stats.AggregationData;
@@ -297,6 +298,9 @@ public class MutableAggregationTest {
         .isEqualTo(Point.create(Value.longValue(0), TIMESTAMP));
     assertThat(MutableMean.create().toPoint(TIMESTAMP))
         .isEqualTo(Point.create(Value.doubleValue(0), TIMESTAMP));
+
+    thrown.expect(IllegalArgumentException.class);
+    thrown.expectMessage("bucket boundaries should be > 0");
     assertThat(MutableDistribution.create(BUCKET_BOUNDARIES).toPoint(TIMESTAMP))
         .isEqualTo(
             Point.create(
@@ -305,17 +309,13 @@ public class MutableAggregationTest {
                         0,
                         0,
                         0,
-                        BUCKET_BOUNDARIES.getBoundaries(),
+                        BucketOptions.explicitOptions(BUCKET_BOUNDARIES.getBoundaries()),
                         Arrays.asList(
                             Bucket.create(0),
                             Bucket.create(0),
                             Bucket.create(0),
                             Bucket.create(0)))),
                 TIMESTAMP));
-    assertThat(MutableLastValueDouble.create().toPoint(TIMESTAMP))
-        .isEqualTo(Point.create(Value.doubleValue(Double.NaN), TIMESTAMP));
-    assertThat(MutableLastValueLong.create().toPoint(TIMESTAMP))
-        .isEqualTo(Point.create(Value.longValue(0), TIMESTAMP));
   }
 
   private static void verifyMutableDistribution(