Cleanup: Move static util methods to util class. (#1343)

* Cleanup: Move static util methods to util class.

* Fix checker framework.

5 files changed, 166 insertions, 133 deletions

diff --git a/impl_core/src/test/java/io/opencensus/implcore/stats/MutableViewDataTest.java b/impl_core/src/test/java/io/opencensus/implcore/stats/MutableViewDataTest.java
index e397ad65..06f50fed 100644
--- a/impl_core/src/test/java/io/opencensus/implcore/stats/MutableViewDataTest.java
+++ b/impl_core/src/test/java/io/opencensus/implcore/stats/MutableViewDataTest.java
@@ -18,35 +18,7 @@ package io.opencensus.implcore.stats;
 
 import static com.google.common.truth.Truth.assertThat;
 
-import com.google.common.collect.ImmutableMap;
 import io.opencensus.common.Timestamp;
-import io.opencensus.implcore.stats.MutableAggregation.MutableCount;
-import io.opencensus.implcore.stats.MutableAggregation.MutableDistribution;
-import io.opencensus.implcore.stats.MutableAggregation.MutableLastValue;
-import io.opencensus.implcore.stats.MutableAggregation.MutableMean;
-import io.opencensus.implcore.stats.MutableAggregation.MutableSum;
-import io.opencensus.stats.Aggregation.Count;
-import io.opencensus.stats.Aggregation.Distribution;
-import io.opencensus.stats.Aggregation.LastValue;
-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.LastValueDataDouble;
-import io.opencensus.stats.AggregationData.LastValueDataLong;
-import io.opencensus.stats.AggregationData.MeanData;
-import io.opencensus.stats.AggregationData.SumDataDouble;
-import io.opencensus.stats.AggregationData.SumDataLong;
-import io.opencensus.stats.BucketBoundaries;
-import io.opencensus.stats.Measure.MeasureDouble;
-import io.opencensus.stats.Measure.MeasureLong;
-import io.opencensus.tags.TagKey;
-import io.opencensus.tags.TagValue;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.List;
-import java.util.Map;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
@@ -55,94 +27,8 @@ import org.junit.runners.JUnit4;
 @RunWith(JUnit4.class)
 public class MutableViewDataTest {
 
-  private static final double EPSILON = 1e-7;
-
-  private static final TagKey ORIGINATOR = TagKey.create("originator");
-  private static final TagKey CALLER = TagKey.create("caller");
-  private static final TagKey METHOD = TagKey.create("method");
-  private static final TagValue CALLER_V = TagValue.create("some caller");
-  private static final TagValue METHOD_V = TagValue.create("some method");
-  private static final MeasureDouble MEASURE_DOUBLE =
-      MeasureDouble.create("measure1", "description", "1");
-  private static final MeasureLong MEASURE_LONG =
-      MeasureLong.create("measure2", "description", "1");
-
   @Test
   public void testConstants() {
-    assertThat(MutableViewData.UNKNOWN_TAG_VALUE).isNull();
     assertThat(MutableViewData.ZERO_TIMESTAMP).isEqualTo(Timestamp.create(0, 0));
   }
-
-  @Test
-  public void testGetTagValues() {
-    List<TagKey> columns = Arrays.asList(CALLER, METHOD, ORIGINATOR);
-    Map<TagKey, TagValue> tags = ImmutableMap.of(CALLER, CALLER_V, METHOD, METHOD_V);
-
-    assertThat(MutableViewData.getTagValues(tags, columns))
-        .containsExactly(CALLER_V, METHOD_V, MutableViewData.UNKNOWN_TAG_VALUE)
-        .inOrder();
-  }
-
-  @Test
-  public void createMutableAggregation() {
-    BucketBoundaries bucketBoundaries = BucketBoundaries.create(Arrays.asList(-1.0, 0.0, 1.0));
-
-    assertThat(((MutableSum) MutableViewData.createMutableAggregation(Sum.create())).getSum())
-        .isWithin(EPSILON)
-        .of(0.0);
-    assertThat(((MutableCount) MutableViewData.createMutableAggregation(Count.create())).getCount())
-        .isEqualTo(0L);
-    assertThat(((MutableMean) MutableViewData.createMutableAggregation(Mean.create())).getMean())
-        .isWithin(EPSILON)
-        .of(0D);
-    assertThat(
-            ((MutableLastValue) MutableViewData.createMutableAggregation(LastValue.create()))
-                .getLastValue())
-        .isNaN();
-
-    MutableDistribution mutableDistribution =
-        (MutableDistribution)
-            MutableViewData.createMutableAggregation(Distribution.create(bucketBoundaries));
-    assertThat(mutableDistribution.getMin()).isPositiveInfinity();
-    assertThat(mutableDistribution.getMax()).isNegativeInfinity();
-    assertThat(mutableDistribution.getSumOfSquaredDeviations()).isWithin(EPSILON).of(0);
-    assertThat(mutableDistribution.getBucketCounts()).isEqualTo(new long[4]);
-  }
-
-  @Test
-  public void createAggregationData() {
-    BucketBoundaries bucketBoundaries = BucketBoundaries.create(Arrays.asList(-1.0, 0.0, 1.0));
-    List<AggregationData> aggregates = new ArrayList<AggregationData>();
-    aggregates.add(MutableViewData.createAggregationData(MutableSum.create(), MEASURE_DOUBLE));
-    aggregates.add(MutableViewData.createAggregationData(MutableSum.create(), MEASURE_LONG));
-    aggregates.add(
-        MutableViewData.createAggregationData(MutableLastValue.create(), MEASURE_DOUBLE));
-    aggregates.add(MutableViewData.createAggregationData(MutableLastValue.create(), MEASURE_LONG));
-
-    List<MutableAggregation> mutableAggregations =
-        Arrays.asList(
-            MutableCount.create(),
-            MutableMean.create(),
-            MutableDistribution.create(bucketBoundaries));
-    for (MutableAggregation mutableAggregation : mutableAggregations) {
-      aggregates.add(MutableViewData.createAggregationData(mutableAggregation, MEASURE_DOUBLE));
-    }
-
-    assertThat(aggregates)
-        .containsExactly(
-            SumDataDouble.create(0),
-            SumDataLong.create(0),
-            LastValueDataDouble.create(Double.NaN),
-            LastValueDataLong.create(0),
-            CountData.create(0),
-            MeanData.create(0, 0),
-            DistributionData.create(
-                0,
-                0,
-                Double.POSITIVE_INFINITY,
-                Double.NEGATIVE_INFINITY,
-                0,
-                Arrays.asList(new Long[] {0L, 0L, 0L, 0L})))
-        .inOrder();
-  }
 }
diff --git a/impl_core/src/test/java/io/opencensus/implcore/stats/RecordUtilsTest.java b/impl_core/src/test/java/io/opencensus/implcore/stats/RecordUtilsTest.java
new file mode 100644
index 00000000..7a4b1b3d
--- /dev/null
+++ b/impl_core/src/test/java/io/opencensus/implcore/stats/RecordUtilsTest.java
@@ -0,0 +1,144 @@
+/*
+ * Copyright 2018, OpenCensus Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.opencensus.implcore.stats;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import com.google.common.collect.ImmutableMap;
+import io.opencensus.implcore.stats.MutableAggregation.MutableCount;
+import io.opencensus.implcore.stats.MutableAggregation.MutableDistribution;
+import io.opencensus.implcore.stats.MutableAggregation.MutableLastValue;
+import io.opencensus.implcore.stats.MutableAggregation.MutableMean;
+import io.opencensus.implcore.stats.MutableAggregation.MutableSum;
+import io.opencensus.stats.Aggregation.Count;
+import io.opencensus.stats.Aggregation.Distribution;
+import io.opencensus.stats.Aggregation.LastValue;
+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.LastValueDataDouble;
+import io.opencensus.stats.AggregationData.LastValueDataLong;
+import io.opencensus.stats.AggregationData.MeanData;
+import io.opencensus.stats.AggregationData.SumDataDouble;
+import io.opencensus.stats.AggregationData.SumDataLong;
+import io.opencensus.stats.BucketBoundaries;
+import io.opencensus.stats.Measure.MeasureDouble;
+import io.opencensus.stats.Measure.MeasureLong;
+import io.opencensus.tags.TagKey;
+import io.opencensus.tags.TagValue;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Map;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+/** Tests for {@link RecordUtils}. */
+@RunWith(JUnit4.class)
+public class RecordUtilsTest {
+
+  private static final double EPSILON = 1e-7;
+  private static final MeasureDouble MEASURE_DOUBLE =
+      MeasureDouble.create("measure1", "description", "1");
+  private static final MeasureLong MEASURE_LONG =
+      MeasureLong.create("measure2", "description", "1");
+  private static final TagKey ORIGINATOR = TagKey.create("originator");
+  private static final TagKey CALLER = TagKey.create("caller");
+  private static final TagKey METHOD = TagKey.create("method");
+  private static final TagValue CALLER_V = TagValue.create("some caller");
+  private static final TagValue METHOD_V = TagValue.create("some method");
+
+  @Test
+  public void testConstants() {
+    assertThat(RecordUtils.UNKNOWN_TAG_VALUE).isNull();
+  }
+
+  @Test
+  public void testGetTagValues() {
+    List<TagKey> columns = Arrays.asList(CALLER, METHOD, ORIGINATOR);
+    Map<TagKey, TagValue> tags = ImmutableMap.of(CALLER, CALLER_V, METHOD, METHOD_V);
+
+    assertThat(RecordUtils.getTagValues(tags, columns))
+        .containsExactly(CALLER_V, METHOD_V, RecordUtils.UNKNOWN_TAG_VALUE)
+        .inOrder();
+  }
+
+  @Test
+  public void createMutableAggregation() {
+    BucketBoundaries bucketBoundaries = BucketBoundaries.create(Arrays.asList(-1.0, 0.0, 1.0));
+
+    assertThat(((MutableSum) RecordUtils.createMutableAggregation(Sum.create())).getSum())
+        .isWithin(EPSILON)
+        .of(0.0);
+    assertThat(((MutableCount) RecordUtils.createMutableAggregation(Count.create())).getCount())
+        .isEqualTo(0L);
+    assertThat(((MutableMean) RecordUtils.createMutableAggregation(Mean.create())).getMean())
+        .isWithin(EPSILON)
+        .of(0D);
+    assertThat(
+            ((MutableLastValue) RecordUtils.createMutableAggregation(LastValue.create()))
+                .getLastValue())
+        .isNaN();
+
+    MutableDistribution mutableDistribution =
+        (MutableDistribution)
+            RecordUtils.createMutableAggregation(Distribution.create(bucketBoundaries));
+    assertThat(mutableDistribution.getMin()).isPositiveInfinity();
+    assertThat(mutableDistribution.getMax()).isNegativeInfinity();
+    assertThat(mutableDistribution.getSumOfSquaredDeviations()).isWithin(EPSILON).of(0);
+    assertThat(mutableDistribution.getBucketCounts()).isEqualTo(new long[4]);
+  }
+
+  @Test
+  public void createAggregationData() {
+    BucketBoundaries bucketBoundaries = BucketBoundaries.create(Arrays.asList(-1.0, 0.0, 1.0));
+    List<AggregationData> aggregates = new ArrayList<AggregationData>();
+    aggregates.add(RecordUtils.createAggregationData(MutableSum.create(), MEASURE_DOUBLE));
+    aggregates.add(RecordUtils.createAggregationData(MutableSum.create(), MEASURE_LONG));
+    aggregates.add(RecordUtils.createAggregationData(MutableLastValue.create(), MEASURE_DOUBLE));
+    aggregates.add(RecordUtils.createAggregationData(MutableLastValue.create(), MEASURE_LONG));
+
+    List<MutableAggregation> mutableAggregations =
+        Arrays.asList(
+            MutableCount.create(),
+            MutableMean.create(),
+            MutableDistribution.create(bucketBoundaries));
+    for (MutableAggregation mutableAggregation : mutableAggregations) {
+      aggregates.add(RecordUtils.createAggregationData(mutableAggregation, MEASURE_DOUBLE));
+    }
+
+    assertThat(aggregates)
+        .containsExactly(
+            SumDataDouble.create(0),
+            SumDataLong.create(0),
+            LastValueDataDouble.create(Double.NaN),
+            LastValueDataLong.create(0),
+            CountData.create(0),
+            MeanData.create(0, 0),
+            DistributionData.create(
+                0,
+                0,
+                Double.POSITIVE_INFINITY,
+                Double.NEGATIVE_INFINITY,
+                0,
+                Arrays.asList(0L, 0L, 0L, 0L)))
+        .inOrder();
+  }
+}
diff --git a/impl_core/src/test/java/io/opencensus/implcore/stats/StatsRecorderImplTest.java b/impl_core/src/test/java/io/opencensus/implcore/stats/StatsRecorderImplTest.java
index 3c8d7af3..bd8b5b88 100644
--- a/impl_core/src/test/java/io/opencensus/implcore/stats/StatsRecorderImplTest.java
+++ b/impl_core/src/test/java/io/opencensus/implcore/stats/StatsRecorderImplTest.java
@@ -21,11 +21,11 @@ import static io.opencensus.implcore.stats.MutableViewData.ZERO_TIMESTAMP;
 import static io.opencensus.implcore.stats.StatsTestUtil.createEmptyViewData;
 
 import com.google.common.collect.ImmutableMap;
-import com.google.common.collect.Lists;
 import io.grpc.Context;
 import io.opencensus.common.Duration;
 import io.opencensus.common.Timestamp;
 import io.opencensus.implcore.internal.SimpleEventQueue;
+import io.opencensus.implcore.stats.StatsTestUtil.SimpleTagContext;
 import io.opencensus.stats.Aggregation.Count;
 import io.opencensus.stats.Aggregation.Distribution;
 import io.opencensus.stats.Aggregation.Sum;
@@ -51,7 +51,6 @@ import io.opencensus.tags.unsafe.ContextUtils;
 import io.opencensus.testing.common.TestClock;
 import java.util.Arrays;
 import java.util.Collections;
-import java.util.Iterator;
 import java.util.List;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -347,17 +346,4 @@ public final class StatsRecorderImplTest {
             StatsTestUtil.createAggregationData(Sum.create(), MEASURE_DOUBLE, 4.0)),
         1e-6);
   }
-
-  private static final class SimpleTagContext extends TagContext {
-    private final List<Tag> tags;
-
-    SimpleTagContext(Tag... tags) {
-      this.tags = Collections.unmodifiableList(Lists.newArrayList(tags));
-    }
-
-    @Override
-    protected Iterator<Tag> getIterator() {
-      return tags.iterator();
-    }
-  }
 }
diff --git a/impl_core/src/test/java/io/opencensus/implcore/stats/StatsTestUtil.java b/impl_core/src/test/java/io/opencensus/implcore/stats/StatsTestUtil.java
index 6a2e6366..ec436d22 100644
--- a/impl_core/src/test/java/io/opencensus/implcore/stats/StatsTestUtil.java
+++ b/impl_core/src/test/java/io/opencensus/implcore/stats/StatsTestUtil.java
@@ -20,6 +20,7 @@ import static com.google.common.truth.Truth.assertThat;
 import static io.opencensus.implcore.stats.MutableViewData.ZERO_TIMESTAMP;
 
 import com.google.common.collect.Iterables;
+import com.google.common.collect.Lists;
 import io.opencensus.common.Function;
 import io.opencensus.common.Functions;
 import io.opencensus.common.Timestamp;
@@ -38,9 +39,12 @@ import io.opencensus.stats.ViewData;
 import io.opencensus.stats.ViewData.AggregationWindowData;
 import io.opencensus.stats.ViewData.AggregationWindowData.CumulativeData;
 import io.opencensus.stats.ViewData.AggregationWindowData.IntervalData;
+import io.opencensus.tags.Tag;
+import io.opencensus.tags.TagContext;
 import io.opencensus.tags.TagValue;
 import java.util.ArrayList;
 import java.util.Collections;
+import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
@@ -63,11 +67,11 @@ final class StatsTestUtil {
    */
   static AggregationData createAggregationData(
       Aggregation aggregation, Measure measure, double... values) {
-    MutableAggregation mutableAggregation = MutableViewData.createMutableAggregation(aggregation);
+    MutableAggregation mutableAggregation = RecordUtils.createMutableAggregation(aggregation);
     for (double value : values) {
       mutableAggregation.add(value, Collections.<String, String>emptyMap(), EMPTY);
     }
-    return MutableViewData.createAggregationData(mutableAggregation, measure);
+    return RecordUtils.createAggregationData(mutableAggregation, measure);
   }
 
   /**
@@ -211,4 +215,17 @@ final class StatsTestUtil {
     }
     return truncated;
   }
+
+  static final class SimpleTagContext extends TagContext {
+    private final List<Tag> tags;
+
+    SimpleTagContext(Tag... tags) {
+      this.tags = Collections.unmodifiableList(Lists.newArrayList(tags));
+    }
+
+    @Override
+    protected Iterator<Tag> getIterator() {
+      return tags.iterator();
+    }
+  }
 }
diff --git a/impl_core/src/test/java/io/opencensus/implcore/stats/ViewManagerImplTest.java b/impl_core/src/test/java/io/opencensus/implcore/stats/ViewManagerImplTest.java
index 270d65c0..b3ec6f2d 100644
--- a/impl_core/src/test/java/io/opencensus/implcore/stats/ViewManagerImplTest.java
+++ b/impl_core/src/test/java/io/opencensus/implcore/stats/ViewManagerImplTest.java
@@ -634,7 +634,7 @@ public class ViewManagerImplTest {
         ImmutableMap.of(
             // Tag is missing for associated measureValues, should use default tag value
             // "unknown/not set".
-            Arrays.asList(MutableViewData.UNKNOWN_TAG_VALUE),
+            Arrays.asList(RecordUtils.UNKNOWN_TAG_VALUE),
             // Should record stats with default tag value: "KEY" : "unknown/not set".
             createAggregationData(DISTRIBUTION, MEASURE_DOUBLE, 10.0)),
         EPSILON);
@@ -682,7 +682,7 @@ public class ViewManagerImplTest {
         ImmutableMap.of(
             // Won't record the unregistered tag key, for missing registered keys will use default
             // tag value : "unknown/not set".
-            Arrays.asList(MutableViewData.UNKNOWN_TAG_VALUE),
+            Arrays.asList(RecordUtils.UNKNOWN_TAG_VALUE),
             // Should record stats with default tag value: "KEY" : "unknown/not set".
             createAggregationData(DISTRIBUTION, MEASURE_DOUBLE, 10.0, 50.0)),
         EPSILON);