Improve Duration.toMillis() (#1132)

* Improve java doc for toMillis().

* Make toMillis() non-static.

3 files changed, 5 insertions, 5 deletions

diff --git a/impl_core/src/main/java/io/opencensus/implcore/stats/IntervalBucket.java b/impl_core/src/main/java/io/opencensus/implcore/stats/IntervalBucket.java
index f114bea6..65b768da 100644
--- a/impl_core/src/main/java/io/opencensus/implcore/stats/IntervalBucket.java
+++ b/impl_core/src/main/java/io/opencensus/implcore/stats/IntervalBucket.java
@@ -81,7 +81,7 @@ final class IntervalBucket {
     checkArgument(
         elapsedTime.compareTo(ZERO) >= 0 && elapsedTime.compareTo(duration) < 0,
         "This bucket must be current.");
-    return ((double) Duration.toMillis(elapsedTime)) / Duration.toMillis(duration);
+    return ((double) elapsedTime.toMillis()) / duration.toMillis();
   }
 
   void clearStats() {
diff --git a/impl_core/src/main/java/io/opencensus/implcore/stats/MutableViewData.java b/impl_core/src/main/java/io/opencensus/implcore/stats/MutableViewData.java
index f0938c06..d60715b5 100644
--- a/impl_core/src/main/java/io/opencensus/implcore/stats/MutableViewData.java
+++ b/impl_core/src/main/java/io/opencensus/implcore/stats/MutableViewData.java
@@ -287,7 +287,7 @@ abstract class MutableViewData {
       super(view);
       Duration totalDuration = ((View.AggregationWindow.Interval) view.getWindow()).getDuration();
       this.totalDuration = totalDuration;
-      this.bucketDuration = Duration.fromMillis(Duration.toMillis(totalDuration) / N);
+      this.bucketDuration = Duration.fromMillis(totalDuration.toMillis() / N);
 
       // When initializing. add N empty buckets prior to the start timestamp of this
       // IntervalMutableViewData, so that the last bucket will be the current one in effect.
@@ -346,8 +346,8 @@ abstract class MutableViewData {
       checkArgument(
           now.compareTo(startOfLastBucket) >= 0,
           "Current time must be within or after the last bucket.");
-      long elapsedTimeMillis = Duration.toMillis(now.subtractTimestamp(startOfLastBucket));
-      long numOfPadBuckets = elapsedTimeMillis / Duration.toMillis(bucketDuration);
+      long elapsedTimeMillis = now.subtractTimestamp(startOfLastBucket).toMillis();
+      long numOfPadBuckets = elapsedTimeMillis / bucketDuration.toMillis();
 
       shiftBucketList(numOfPadBuckets, now);
     }
diff --git a/impl_core/src/main/java/io/opencensus/implcore/trace/export/SpanExporterImpl.java b/impl_core/src/main/java/io/opencensus/implcore/trace/export/SpanExporterImpl.java
index c8ed237d..e702d38c 100644
--- a/impl_core/src/main/java/io/opencensus/implcore/trace/export/SpanExporterImpl.java
+++ b/impl_core/src/main/java/io/opencensus/implcore/trace/export/SpanExporterImpl.java
@@ -145,7 +145,7 @@ public final class SpanExporterImpl extends SpanExporter {
     private Worker(int bufferSize, Duration scheduleDelay) {
       spans = new ArrayList<SpanImpl>(bufferSize);
       this.bufferSize = bufferSize;
-      this.scheduleDelayMillis = Duration.toMillis(scheduleDelay);
+      this.scheduleDelayMillis = scheduleDelay.toMillis();
     }
 
     // Returns an unmodifiable list of all buffered spans data to ensure that any registered