Deprecate Mean and MeanData (#1101)

* Deprecate Mean and MeanData

* Suppress deprecation warnings.

* Suppress warning InconsistentOverloads

* CopyAnnotations for AutoValue Mean and MeanData

10 files changed, 157 insertions, 48 deletions

diff --git a/api/src/main/java/io/opencensus/stats/Aggregation.java b/api/src/main/java/io/opencensus/stats/Aggregation.java
index 4362b4a8..55ce9d96 100644
--- a/api/src/main/java/io/opencensus/stats/Aggregation.java
+++ b/api/src/main/java/io/opencensus/stats/Aggregation.java
@@ -26,12 +26,11 @@ import javax.annotation.concurrent.Immutable;
  * {@link Aggregation} is the process of combining a certain set of {@code MeasureValue}s for a
  * given {@code Measure} into an {@link AggregationData}.
  *
- * <p>{@link Aggregation} currently supports 4 types of basic aggregation:
+ * <p>{@link Aggregation} currently supports 3 types of basic aggregation:
  *
  * <ul>
  *   <li>Sum
  *   <li>Count
- *   <li>Mean
  *   <li>Distribution
  * </ul>
  *
@@ -49,7 +48,9 @@ public abstract class Aggregation {
    * Applies the given match function to the underlying data type.
    *
    * @since 0.8
+   * @deprecated in favor of {@link #match(Function, Function, Function, Function)}.
    */
+  @Deprecated
   public abstract <T> T match(
       Function<? super Sum, T> p0,
       Function<? super Count, T> p1,
@@ -58,6 +59,18 @@ public abstract class Aggregation {
       Function<? super Aggregation, T> defaultFunction);
 
   /**
+   * Applies the given match function to the underlying data type.
+   *
+   * @since 0.13
+   */
+  @SuppressWarnings("InconsistentOverloads")
+  public abstract <T> T match(
+      Function<? super Sum, T> p0,
+      Function<? super Count, T> p1,
+      Function<? super Distribution, T> p2,
+      Function<? super Aggregation, T> defaultFunction);
+
+  /**
    * Calculate sum on aggregated {@code MeasureValue}s.
    *
    * @since 0.8
@@ -89,6 +102,15 @@ public abstract class Aggregation {
         Function<? super Aggregation, T> defaultFunction) {
       return p0.apply(this);
     }
+
+    @Override
+    public final <T> T match(
+        Function<? super Sum, T> p0,
+        Function<? super Count, T> p1,
+        Function<? super Distribution, T> p2,
+        Function<? super Aggregation, T> defaultFunction) {
+      return p0.apply(this);
+    }
   }
 
   /**
@@ -123,15 +145,27 @@ public abstract class Aggregation {
         Function<? super Aggregation, T> defaultFunction) {
       return p1.apply(this);
     }
+
+    @Override
+    public final <T> T match(
+        Function<? super Sum, T> p0,
+        Function<? super Count, T> p1,
+        Function<? super Distribution, T> p2,
+        Function<? super Aggregation, T> defaultFunction) {
+      return p1.apply(this);
+    }
   }
 
   /**
    * Calculate mean on aggregated {@code MeasureValue}s.
    *
    * @since 0.8
+   * @deprecated since 0.13, use {@link Distribution} instead.
    */
   @Immutable
   @AutoValue
+  @Deprecated
+  @AutoValue.CopyAnnotations
   public abstract static class Mean extends Aggregation {
 
     Mean() {}
@@ -157,6 +191,15 @@ public abstract class Aggregation {
         Function<? super Aggregation, T> defaultFunction) {
       return p2.apply(this);
     }
+
+    @Override
+    public final <T> T match(
+        Function<? super Sum, T> p0,
+        Function<? super Count, T> p1,
+        Function<? super Distribution, T> p2,
+        Function<? super Aggregation, T> defaultFunction) {
+      return defaultFunction.apply(this);
+    }
   }
 
   /**
@@ -199,5 +242,14 @@ public abstract class Aggregation {
         Function<? super Aggregation, T> defaultFunction) {
       return p3.apply(this);
     }
+
+    @Override
+    public final <T> T match(
+        Function<? super Sum, T> p0,
+        Function<? super Count, T> p1,
+        Function<? super Distribution, T> p2,
+        Function<? super Aggregation, T> defaultFunction) {
+      return p2.apply(this);
+    }
   }
 }
diff --git a/api/src/main/java/io/opencensus/stats/AggregationData.java b/api/src/main/java/io/opencensus/stats/AggregationData.java
index 50feb034..637621e9 100644
--- a/api/src/main/java/io/opencensus/stats/AggregationData.java
+++ b/api/src/main/java/io/opencensus/stats/AggregationData.java
@@ -30,13 +30,12 @@ import javax.annotation.concurrent.Immutable;
  * {@link AggregationData} is the result of applying a given {@link Aggregation} to a set of {@code
  * MeasureValue}s.
  *
- * <p>{@link AggregationData} currently supports 5 types of basic aggregation values:
+ * <p>{@link AggregationData} currently supports 4 types of basic aggregation values:
  *
  * <ul>
  *   <li>SumDataDouble
  *   <li>SumDataLong
  *   <li>CountData
- *   <li>MeanData
  *   <li>DistributionData
  * </ul>
  *
@@ -54,7 +53,9 @@ public abstract class AggregationData {
    * Applies the given match function to the underlying data type.
    *
    * @since 0.8
+   * @deprecated in favor of {@link #match(Function, Function, Function, Function, Function)}.
    */
+  @Deprecated
   public abstract <T> T match(
       Function<? super SumDataDouble, T> p0,
       Function<? super SumDataLong, T> p1,
@@ -64,6 +65,19 @@ public abstract class AggregationData {
       Function<? super AggregationData, T> defaultFunction);
 
   /**
+   * Applies the given match function to the underlying data type.
+   *
+   * @since 0.13
+   */
+  @SuppressWarnings("InconsistentOverloads")
+  public abstract <T> T match(
+      Function<? super SumDataDouble, T> p0,
+      Function<? super SumDataLong, T> p1,
+      Function<? super CountData, T> p2,
+      Function<? super DistributionData, T> p3,
+      Function<? super AggregationData, T> defaultFunction);
+
+  /**
    * The sum value of aggregated {@code MeasureValueDouble}s.
    *
    * @since 0.8
@@ -103,6 +117,16 @@ public abstract class AggregationData {
         Function<? super AggregationData, T> defaultFunction) {
       return p0.apply(this);
     }
+
+    @Override
+    public final <T> T match(
+        Function<? super SumDataDouble, T> p0,
+        Function<? super SumDataLong, T> p1,
+        Function<? super CountData, T> p2,
+        Function<? super DistributionData, T> p3,
+        Function<? super AggregationData, T> defaultFunction) {
+      return p0.apply(this);
+    }
   }
 
   /**
@@ -145,6 +169,16 @@ public abstract class AggregationData {
         Function<? super AggregationData, T> defaultFunction) {
       return p1.apply(this);
     }
+
+    @Override
+    public final <T> T match(
+        Function<? super SumDataDouble, T> p0,
+        Function<? super SumDataLong, T> p1,
+        Function<? super CountData, T> p2,
+        Function<? super DistributionData, T> p3,
+        Function<? super AggregationData, T> defaultFunction) {
+      return p1.apply(this);
+    }
   }
 
   /**
@@ -187,15 +221,28 @@ public abstract class AggregationData {
         Function<? super AggregationData, T> defaultFunction) {
       return p2.apply(this);
     }
+
+    @Override
+    public final <T> T match(
+        Function<? super SumDataDouble, T> p0,
+        Function<? super SumDataLong, T> p1,
+        Function<? super CountData, T> p2,
+        Function<? super DistributionData, T> p3,
+        Function<? super AggregationData, T> defaultFunction) {
+      return p2.apply(this);
+    }
   }
 
   /**
    * The mean value of aggregated {@code MeasureValue}s.
    *
    * @since 0.8
+   * @deprecated since 0.13, use {@link DistributionData} instead.
    */
   @Immutable
   @AutoValue
+  @Deprecated
+  @AutoValue.CopyAnnotations
   public abstract static class MeanData extends AggregationData {
 
     MeanData() {}
@@ -238,6 +285,16 @@ public abstract class AggregationData {
         Function<? super AggregationData, T> defaultFunction) {
       return p3.apply(this);
     }
+
+    @Override
+    public final <T> T match(
+        Function<? super SumDataDouble, T> p0,
+        Function<? super SumDataLong, T> p1,
+        Function<? super CountData, T> p2,
+        Function<? super DistributionData, T> p3,
+        Function<? super AggregationData, T> defaultFunction) {
+      return defaultFunction.apply(this);
+    }
   }
 
   /**
@@ -344,5 +401,15 @@ public abstract class AggregationData {
         Function<? super AggregationData, T> defaultFunction) {
       return p4.apply(this);
     }
+
+    @Override
+    public final <T> T match(
+        Function<? super SumDataDouble, T> p0,
+        Function<? super SumDataLong, T> p1,
+        Function<? super CountData, T> p2,
+        Function<? super DistributionData, T> p3,
+        Function<? super AggregationData, T> defaultFunction) {
+      return p3.apply(this);
+    }
   }
 }
diff --git a/api/src/main/java/io/opencensus/stats/ViewData.java b/api/src/main/java/io/opencensus/stats/ViewData.java
index ef9a6795..788bea76 100644
--- a/api/src/main/java/io/opencensus/stats/ViewData.java
+++ b/api/src/main/java/io/opencensus/stats/ViewData.java
@@ -25,11 +25,9 @@ import io.opencensus.common.Functions;
 import io.opencensus.common.Timestamp;
 import io.opencensus.stats.Aggregation.Count;
 import io.opencensus.stats.Aggregation.Distribution;
-import io.opencensus.stats.Aggregation.Mean;
 import io.opencensus.stats.Aggregation.Sum;
 import io.opencensus.stats.AggregationData.CountData;
 import io.opencensus.stats.AggregationData.DistributionData;
-import io.opencensus.stats.AggregationData.MeanData;
 import io.opencensus.stats.AggregationData.SumDataDouble;
 import io.opencensus.stats.AggregationData.SumDataLong;
 import io.opencensus.stats.Measure.MeasureDouble;
@@ -275,11 +273,11 @@ public abstract class ViewData {
             return null;
           }
         },
-        new Function<Mean, Void>() {
+        new Function<Aggregation.Mean, Void>() {
           @Override
-          public Void apply(Mean arg) {
+          public Void apply(Aggregation.Mean arg) {
             checkArgument(
-                aggregationData instanceof MeanData,
+                aggregationData instanceof AggregationData.MeanData,
                 createErrorMessageForAggregation(aggregation, aggregationData));
             return null;
           }
diff --git a/contrib/grpc_metrics/src/main/java/io/opencensus/contrib/grpc/metrics/RpcViewConstants.java b/contrib/grpc_metrics/src/main/java/io/opencensus/contrib/grpc/metrics/RpcViewConstants.java
index 81eea400..ef3a9671 100644
--- a/contrib/grpc_metrics/src/main/java/io/opencensus/contrib/grpc/metrics/RpcViewConstants.java
+++ b/contrib/grpc_metrics/src/main/java/io/opencensus/contrib/grpc/metrics/RpcViewConstants.java
@@ -46,7 +46,6 @@ import io.opencensus.common.Duration;
 import io.opencensus.stats.Aggregation;
 import io.opencensus.stats.Aggregation.Count;
 import io.opencensus.stats.Aggregation.Distribution;
-import io.opencensus.stats.Aggregation.Mean;
 import io.opencensus.stats.BucketBoundaries;
 import io.opencensus.stats.View;
 import java.util.Arrays;
@@ -99,7 +98,7 @@ public final class RpcViewConstants {
               4096.0, 8192.0, 16384.0, 32768.0, 65536.0));
 
   // Use Aggregation.Mean to record sum and count stats at the same time.
-  @VisibleForTesting static final Aggregation MEAN = Mean.create();
+  @VisibleForTesting static final Aggregation MEAN = Aggregation.Mean.create();
   @VisibleForTesting static final Aggregation COUNT = Count.create();
 
   @VisibleForTesting
diff --git a/contrib/zpages/src/main/java/io/opencensus/contrib/zpages/RpczZPageHandler.java b/contrib/zpages/src/main/java/io/opencensus/contrib/zpages/RpczZPageHandler.java
index 56ccb734..c0ec5354 100644
--- a/contrib/zpages/src/main/java/io/opencensus/contrib/zpages/RpczZPageHandler.java
+++ b/contrib/zpages/src/main/java/io/opencensus/contrib/zpages/RpczZPageHandler.java
@@ -85,7 +85,6 @@ import io.opencensus.common.Duration;
 import io.opencensus.stats.AggregationData;
 import io.opencensus.stats.AggregationData.CountData;
 import io.opencensus.stats.AggregationData.DistributionData;
-import io.opencensus.stats.AggregationData.MeanData;
 import io.opencensus.stats.View;
 import io.opencensus.stats.ViewData;
 import io.opencensus.stats.ViewManager;
@@ -371,18 +370,18 @@ final class RpczZPageHandler extends ZPageHandler {
       snapshot.avgLatencyTotal = ((DistributionData) data).getMean();
     } else if (view == RPC_CLIENT_ROUNDTRIP_LATENCY_MINUTE_VIEW
         || view == RPC_SERVER_SERVER_LATENCY_MINUTE_VIEW) {
-      snapshot.avgLatencyLastMinute = ((MeanData) data).getMean();
+      snapshot.avgLatencyLastMinute = ((AggregationData.MeanData) data).getMean();
     } else if (view == RPC_CLIENT_ROUNDTRIP_LATENCY_HOUR_VIEW
         || view == RPC_SERVER_SERVER_LATENCY_HOUR_VIEW) {
-      snapshot.avgLatencyLastHour = ((MeanData) data).getMean();
+      snapshot.avgLatencyLastHour = ((AggregationData.MeanData) data).getMean();
     } else if (view == RPC_CLIENT_ERROR_COUNT_VIEW || view == RPC_SERVER_ERROR_COUNT_VIEW) {
-      snapshot.errorsTotal = ((MeanData) data).getCount();
+      snapshot.errorsTotal = ((AggregationData.MeanData) data).getCount();
     } else if (view == RPC_CLIENT_ERROR_COUNT_MINUTE_VIEW
         || view == RPC_SERVER_ERROR_COUNT_MINUTE_VIEW) {
-      snapshot.errorsLastMinute = ((MeanData) data).getCount();
+      snapshot.errorsLastMinute = ((AggregationData.MeanData) data).getCount();
     } else if (view == RPC_CLIENT_ERROR_COUNT_HOUR_VIEW
         || view == RPC_SERVER_ERROR_COUNT_HOUR_VIEW) {
-      snapshot.errorsLastHour = ((MeanData) data).getCount();
+      snapshot.errorsLastHour = ((AggregationData.MeanData) data).getCount();
     } else if (view == RPC_CLIENT_REQUEST_BYTES_VIEW || view == RPC_SERVER_REQUEST_BYTES_VIEW) {
       DistributionData distributionData = (DistributionData) data;
       snapshot.inputRateTotal =
@@ -392,12 +391,12 @@ final class RpczZPageHandler extends ZPageHandler {
               / getDurationInSecs((ViewData.AggregationWindowData.CumulativeData) windowData);
     } else if (view == RPC_CLIENT_REQUEST_BYTES_MINUTE_VIEW
         || view == RPC_SERVER_REQUEST_BYTES_MINUTE_VIEW) {
-      MeanData meanData = (MeanData) data;
+      AggregationData.MeanData meanData = (AggregationData.MeanData) data;
       snapshot.inputRateLastMinute =
           meanData.getMean() * meanData.getCount() / BYTES_PER_KB / SECONDS_PER_MINUTE;
     } else if (view == RPC_CLIENT_REQUEST_BYTES_HOUR_VIEW
         || view == RPC_SERVER_REQUEST_BYTES_HOUR_VIEW) {
-      MeanData meanData = (MeanData) data;
+      AggregationData.MeanData meanData = (AggregationData.MeanData) data;
       snapshot.inputRateLastHour =
           meanData.getMean() * meanData.getCount() / BYTES_PER_KB / SECONDS_PER_HOUR;
     } else if (view == RPC_CLIENT_RESPONSE_BYTES_VIEW || view == RPC_SERVER_RESPONSE_BYTES_VIEW) {
@@ -409,12 +408,12 @@ final class RpczZPageHandler extends ZPageHandler {
               / getDurationInSecs((ViewData.AggregationWindowData.CumulativeData) windowData);
     } else if (view == RPC_CLIENT_RESPONSE_BYTES_MINUTE_VIEW
         || view == RPC_SERVER_RESPONSE_BYTES_MINUTE_VIEW) {
-      MeanData meanData = (MeanData) data;
+      AggregationData.MeanData meanData = (AggregationData.MeanData) data;
       snapshot.outputRateLastMinute =
           meanData.getMean() * meanData.getCount() / BYTES_PER_KB / SECONDS_PER_MINUTE;
     } else if (view == RPC_CLIENT_RESPONSE_BYTES_HOUR_VIEW
         || view == RPC_SERVER_RESPONSE_BYTES_HOUR_VIEW) {
-      MeanData meanData = (MeanData) data;
+      AggregationData.MeanData meanData = (AggregationData.MeanData) data;
       snapshot.outputRateLastHour =
           meanData.getMean() * meanData.getCount() / BYTES_PER_KB / SECONDS_PER_HOUR;
     } else if (view == RPC_CLIENT_STARTED_COUNT_MINUTE_VIEW
diff --git a/contrib/zpages/src/main/java/io/opencensus/contrib/zpages/StatszZPageHandler.java b/contrib/zpages/src/main/java/io/opencensus/contrib/zpages/StatszZPageHandler.java
index 03820b1c..21c23d8e 100644
--- a/contrib/zpages/src/main/java/io/opencensus/contrib/zpages/StatszZPageHandler.java
+++ b/contrib/zpages/src/main/java/io/opencensus/contrib/zpages/StatszZPageHandler.java
@@ -28,14 +28,13 @@ import com.google.common.collect.Sets;
 import io.opencensus.common.Function;
 import io.opencensus.common.Functions;
 import io.opencensus.common.Timestamp;
+import io.opencensus.stats.Aggregation;
 import io.opencensus.stats.Aggregation.Count;
 import io.opencensus.stats.Aggregation.Distribution;
-import io.opencensus.stats.Aggregation.Mean;
 import io.opencensus.stats.Aggregation.Sum;
 import io.opencensus.stats.AggregationData;
 import io.opencensus.stats.AggregationData.CountData;
 import io.opencensus.stats.AggregationData.DistributionData;
-import io.opencensus.stats.AggregationData.MeanData;
 import io.opencensus.stats.AggregationData.SumDataDouble;
 import io.opencensus.stats.AggregationData.SumDataLong;
 import io.opencensus.stats.Measure;
@@ -382,9 +381,9 @@ final class StatszZPageHandler extends ZPageHandler {
                 return null;
               }
             },
-            new Function<Mean, Void>() {
+            new Function<Aggregation.Mean, Void>() {
               @Override
-              public Void apply(Mean arg) {
+              public Void apply(Aggregation.Mean arg) {
                 formatter.format("<th class=\"l1\">%s, %s</th>", TABLE_HEADER_MEAN, unit);
                 formatter.format("<th class=\"l1\">%s</th>", TABLE_HEADER_COUNT);
                 return null;
@@ -441,9 +440,9 @@ final class StatszZPageHandler extends ZPageHandler {
                 return null;
               }
             },
-            new Function<MeanData, Void>() {
+            new Function<AggregationData.MeanData, Void>() {
               @Override
-              public Void apply(MeanData arg) {
+              public Void apply(AggregationData.MeanData arg) {
                 formatter.format("<td %s>%.3f</td>", ALIGN_CENTER, arg.getMean());
                 formatter.format("<td %s>%d</td>", ALIGN_CENTER, arg.getCount());
                 return null;
diff --git a/exporters/stats/prometheus/src/main/java/io/opencensus/exporter/stats/prometheus/PrometheusExportUtils.java b/exporters/stats/prometheus/src/main/java/io/opencensus/exporter/stats/prometheus/PrometheusExportUtils.java
index 4a650b97..14920d7b 100644
--- a/exporters/stats/prometheus/src/main/java/io/opencensus/exporter/stats/prometheus/PrometheusExportUtils.java
+++ b/exporters/stats/prometheus/src/main/java/io/opencensus/exporter/stats/prometheus/PrometheusExportUtils.java
@@ -24,12 +24,10 @@ import io.opencensus.common.Functions;
 import io.opencensus.stats.Aggregation;
 import io.opencensus.stats.Aggregation.Count;
 import io.opencensus.stats.Aggregation.Distribution;
-import io.opencensus.stats.Aggregation.Mean;
 import io.opencensus.stats.Aggregation.Sum;
 import io.opencensus.stats.AggregationData;
 import io.opencensus.stats.AggregationData.CountData;
 import io.opencensus.stats.AggregationData.DistributionData;
-import io.opencensus.stats.AggregationData.MeanData;
 import io.opencensus.stats.AggregationData.SumDataDouble;
 import io.opencensus.stats.AggregationData.SumDataLong;
 import io.opencensus.stats.View;
@@ -57,18 +55,18 @@ import org.checkerframework.checker.nullness.qual.Nullable;
  * Cumulative} views are supported. All views are under namespace "opencensus".
  *
  * <p>{@link Aggregation} will be converted to a corresponding Prometheus {@link Type}. {@link Sum}
- * will be {@link Type#UNTYPED}, {@link Count} will be {@link Type#COUNTER}, {@link Mean} will be
- * {@link Type#SUMMARY} and {@link Distribution} will be {@link Type#HISTOGRAM}. Please note we
- * cannot set bucket boundaries for custom {@link Type#HISTOGRAM}.
+ * will be {@link Type#UNTYPED}, {@link Count} will be {@link Type#COUNTER}, {@link
+ * Aggregation.Mean} will be {@link Type#SUMMARY} and {@link Distribution} will be {@link
+ * Type#HISTOGRAM}. Please note we cannot set bucket boundaries for custom {@link Type#HISTOGRAM}.
  *
  * <p>Each OpenCensus {@link ViewData} will be converted to a Prometheus {@link
  * MetricFamilySamples}, and each {@code Row} of the {@link ViewData} will be converted to
  * Prometheus {@link Sample}s.
  *
  * <p>{@link SumDataDouble}, {@link SumDataLong} and {@link CountData} will be converted to a single
- * {@link Sample}. {@link MeanData} will be converted to two {@link Sample}s sum and count. {@link
- * DistributionData} will be converted to a list of {@link Sample}s that have the sum, count and
- * histogram buckets.
+ * {@link Sample}. {@link AggregationData.MeanData} will be converted to two {@link Sample}s sum and
+ * count. {@link DistributionData} will be converted to a list of {@link Sample}s that have the sum,
+ * count and histogram buckets.
  *
  * <p>{@link TagKey} and {@link TagValue} will be converted to Prometheus {@code LabelName} and
  * {@code LabelValue}. {@code Null} {@link TagValue} will be converted to an empty string.
@@ -164,9 +162,9 @@ final class PrometheusExportUtils {
             return null;
           }
         },
-        new Function<MeanData, Void>() {
+        new Function<AggregationData.MeanData, Void>() {
           @Override
-          public Void apply(MeanData arg) {
+          public Void apply(AggregationData.MeanData arg) {
             samples.add(
                 new MetricFamilySamples.Sample(
                     name + SAMPLE_SUFFIX_COUNT, labelNames, labelValues, arg.getCount()));
diff --git a/exporters/stats/signalfx/src/main/java/io/opencensus/exporter/stats/signalfx/SignalFxSessionAdaptor.java b/exporters/stats/signalfx/src/main/java/io/opencensus/exporter/stats/signalfx/SignalFxSessionAdaptor.java
index 67a6dfc6..fb0db8a7 100644
--- a/exporters/stats/signalfx/src/main/java/io/opencensus/exporter/stats/signalfx/SignalFxSessionAdaptor.java
+++ b/exporters/stats/signalfx/src/main/java/io/opencensus/exporter/stats/signalfx/SignalFxSessionAdaptor.java
@@ -29,7 +29,6 @@ import io.opencensus.stats.Aggregation;
 import io.opencensus.stats.AggregationData;
 import io.opencensus.stats.AggregationData.CountData;
 import io.opencensus.stats.AggregationData.DistributionData;
-import io.opencensus.stats.AggregationData.MeanData;
 import io.opencensus.stats.AggregationData.SumDataDouble;
 import io.opencensus.stats.AggregationData.SumDataLong;
 import io.opencensus.stats.View;
@@ -149,9 +148,9 @@ final class SignalFxSessionAdaptor {
             return null;
           }
         },
-        new Function<MeanData, Void>() {
+        new Function<AggregationData.MeanData, Void>() {
           @Override
-          public Void apply(MeanData arg) {
+          public Void apply(AggregationData.MeanData arg) {
             builder.setDoubleValue(arg.getMean());
             return null;
           }
diff --git a/exporters/stats/stackdriver/src/main/java/io/opencensus/exporter/stats/stackdriver/StackdriverExportUtils.java b/exporters/stats/stackdriver/src/main/java/io/opencensus/exporter/stats/stackdriver/StackdriverExportUtils.java
index 78a5456e..a4dc8617 100644
--- a/exporters/stats/stackdriver/src/main/java/io/opencensus/exporter/stats/stackdriver/StackdriverExportUtils.java
+++ b/exporters/stats/stackdriver/src/main/java/io/opencensus/exporter/stats/stackdriver/StackdriverExportUtils.java
@@ -43,7 +43,6 @@ import io.opencensus.stats.Aggregation;
 import io.opencensus.stats.AggregationData;
 import io.opencensus.stats.AggregationData.CountData;
 import io.opencensus.stats.AggregationData.DistributionData;
-import io.opencensus.stats.AggregationData.MeanData;
 import io.opencensus.stats.AggregationData.SumDataDouble;
 import io.opencensus.stats.AggregationData.SumDataLong;
 import io.opencensus.stats.BucketBoundaries;
@@ -297,9 +296,9 @@ final class StackdriverExportUtils {
             return null;
           }
         },
-        new Function<MeanData, Void>() {
+        new Function<AggregationData.MeanData, Void>() {
           @Override
-          public Void apply(MeanData arg) {
+          public Void apply(AggregationData.MeanData arg) {
             builder.setDoubleValue(arg.getMean());
             return null;
           }
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 b82136d3..588b4897 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
@@ -35,12 +35,10 @@ import io.opencensus.implcore.tags.TagContextImpl;
 import io.opencensus.stats.Aggregation;
 import io.opencensus.stats.Aggregation.Count;
 import io.opencensus.stats.Aggregation.Distribution;
-import io.opencensus.stats.Aggregation.Mean;
 import io.opencensus.stats.Aggregation.Sum;
 import io.opencensus.stats.AggregationData;
 import io.opencensus.stats.AggregationData.CountData;
 import io.opencensus.stats.AggregationData.DistributionData;
-import io.opencensus.stats.AggregationData.MeanData;
 import io.opencensus.stats.AggregationData.SumDataDouble;
 import io.opencensus.stats.AggregationData.SumDataLong;
 import io.opencensus.stats.Measure;
@@ -501,9 +499,10 @@ abstract class MutableViewData {
     private static final CreateMutableCount INSTANCE = new CreateMutableCount();
   }
 
-  private static final class CreateMutableMean implements Function<Mean, MutableAggregation> {
+  private static final class CreateMutableMean
+      implements Function<Aggregation.Mean, MutableAggregation> {
     @Override
-    public MutableAggregation apply(Mean arg) {
+    public MutableAggregation apply(Aggregation.Mean arg) {
       return MutableMean.create();
     }
 
@@ -549,7 +548,7 @@ abstract class MutableViewData {
   private static final class CreateMeanData implements Function<MutableMean, AggregationData> {
     @Override
     public AggregationData apply(MutableMean arg) {
-      return MeanData.create(arg.getMean(), arg.getCount());
+      return AggregationData.MeanData.create(arg.getMean(), arg.getCount());
     }
 
     private static final CreateMeanData INSTANCE = new CreateMeanData();