Gauge API : Add DoubleGauge Support (Part2) (#1496)

* Gauge API : Add DoubleGauge Support (Part2)

* Fix review comments

2 files changed, 309 insertions, 17 deletions

diff --git a/impl_core/src/test/java/io/opencensus/implcore/metrics/DoubleGaugeImplTest.java b/impl_core/src/test/java/io/opencensus/implcore/metrics/DoubleGaugeImplTest.java
new file mode 100644
index 00000000..61de77b6
--- /dev/null
+++ b/impl_core/src/test/java/io/opencensus/implcore/metrics/DoubleGaugeImplTest.java
@@ -0,0 +1,292 @@
+/*
+ * 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.metrics;
+
+import static com.google.common.truth.Truth.assertThat;
+import static io.opencensus.implcore.metrics.DoubleGaugeImpl.UNSET_VALUE;
+
+import com.google.common.testing.EqualsTester;
+import io.opencensus.common.Timestamp;
+import io.opencensus.metrics.DoubleGauge.DoublePoint;
+import io.opencensus.metrics.LabelKey;
+import io.opencensus.metrics.LabelValue;
+import io.opencensus.metrics.export.Metric;
+import io.opencensus.metrics.export.MetricDescriptor;
+import io.opencensus.metrics.export.MetricDescriptor.Type;
+import io.opencensus.metrics.export.Point;
+import io.opencensus.metrics.export.TimeSeries;
+import io.opencensus.metrics.export.Value;
+import io.opencensus.testing.common.TestClock;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+/** Unit tests for {@link DoubleGaugeImpl}. */
+@RunWith(JUnit4.class)
+public class DoubleGaugeImplTest {
+  @Rule public ExpectedException thrown = ExpectedException.none();
+
+  private static final String METRIC_NAME = "name";
+  private static final String METRIC_DESCRIPTION = "description";
+  private static final String METRIC_UNIT = "1";
+  private static final List<LabelKey> LABEL_KEY =
+      Collections.singletonList(LabelKey.create("key", "key description"));
+  private static final List<LabelValue> LABEL_VALUES =
+      Collections.singletonList(LabelValue.create("value"));
+  private static final List<LabelValue> LABEL_VALUES1 =
+      Collections.singletonList(LabelValue.create("value1"));
+  private static final List<LabelValue> DEFAULT_LABEL_VALUES =
+      Collections.singletonList(UNSET_VALUE);
+
+  private static final Timestamp TEST_TIME = Timestamp.create(1234, 123);
+  private final TestClock testClock = TestClock.create(TEST_TIME);
+  private static final MetricDescriptor METRIC_DESCRIPTOR =
+      MetricDescriptor.create(
+          METRIC_NAME, METRIC_DESCRIPTION, METRIC_UNIT, Type.GAUGE_DOUBLE, LABEL_KEY);
+  private final DoubleGaugeImpl doubleGauge =
+      new DoubleGaugeImpl(METRIC_NAME, METRIC_DESCRIPTION, METRIC_UNIT, LABEL_KEY);
+
+  @Test
+  public void getOrCreateTimeSeries_WithNullLabelValues() {
+    thrown.expect(NullPointerException.class);
+    thrown.expectMessage("labelValues should not be null.");
+    doubleGauge.getOrCreateTimeSeries(null);
+  }
+
+  @Test
+  public void getOrCreateTimeSeries_WithNullElement() {
+    List<LabelKey> labelKeys =
+        Arrays.asList(LabelKey.create("key1", "desc"), LabelKey.create("key2", "desc"));
+    List<LabelValue> labelValues = Arrays.asList(LabelValue.create("value1"), null);
+
+    DoubleGaugeImpl doubleGauge =
+        new DoubleGaugeImpl(METRIC_NAME, METRIC_DESCRIPTION, METRIC_UNIT, labelKeys);
+    thrown.expect(NullPointerException.class);
+    thrown.expectMessage("labelValues element should not be null.");
+    doubleGauge.getOrCreateTimeSeries(labelValues);
+  }
+
+  @Test
+  public void getOrCreateTimeSeries_WithInvalidLabelSize() {
+    List<LabelValue> labelValues =
+        Arrays.asList(LabelValue.create("value1"), LabelValue.create("value2"));
+
+    thrown.expect(IllegalArgumentException.class);
+    thrown.expectMessage("Incorrect number of labels.");
+    doubleGauge.getOrCreateTimeSeries(labelValues);
+  }
+
+  @Test
+  public void getOrCreateTimeSeries() {
+    DoublePoint point = doubleGauge.getOrCreateTimeSeries(LABEL_VALUES);
+    point.add(100);
+    DoublePoint point1 = doubleGauge.getOrCreateTimeSeries(LABEL_VALUES);
+    point1.set(500);
+
+    Metric metric = doubleGauge.getMetric(testClock);
+    assertThat(metric).isNotNull();
+    assertThat(metric)
+        .isEqualTo(
+            Metric.create(
+                METRIC_DESCRIPTOR,
+                Collections.singletonList(
+                    TimeSeries.createWithOnePoint(
+                        LABEL_VALUES, Point.create(Value.doubleValue(500), TEST_TIME), null))));
+    assertThat(point).isSameAs(point1);
+  }
+
+  @Test
+  public void getOrCreateTimeSeries_WithNegativePointValues() {
+    DoublePoint point = doubleGauge.getOrCreateTimeSeries(LABEL_VALUES);
+    point.add(-100);
+    point.add(-33);
+
+    Metric metric = doubleGauge.getMetric(testClock);
+    assertThat(metric).isNotNull();
+    assertThat(metric.getMetricDescriptor()).isEqualTo(METRIC_DESCRIPTOR);
+    assertThat(metric.getTimeSeriesList().size()).isEqualTo(1);
+    assertThat(metric.getTimeSeriesList().get(0).getPoints().size()).isEqualTo(1);
+    assertThat(metric.getTimeSeriesList().get(0).getPoints().get(0).getValue())
+        .isEqualTo(Value.doubleValue(-133));
+    assertThat(metric.getTimeSeriesList().get(0).getPoints().get(0).getTimestamp())
+        .isEqualTo(TEST_TIME);
+    assertThat(metric.getTimeSeriesList().get(0).getStartTimestamp()).isNull();
+  }
+
+  @Test
+  public void getDefaultTimeSeries() {
+    DoublePoint point = doubleGauge.getDefaultTimeSeries();
+    point.add(100);
+    point.set(500);
+
+    DoublePoint point1 = doubleGauge.getDefaultTimeSeries();
+    point1.add(-100);
+
+    Metric metric = doubleGauge.getMetric(testClock);
+    assertThat(metric).isNotNull();
+    assertThat(metric)
+        .isEqualTo(
+            Metric.create(
+                METRIC_DESCRIPTOR,
+                Collections.singletonList(
+                    TimeSeries.createWithOnePoint(
+                        DEFAULT_LABEL_VALUES,
+                        Point.create(Value.doubleValue(400), TEST_TIME),
+                        null))));
+    assertThat(point).isSameAs(point1);
+  }
+
+  @Test
+  public void removeTimeSeries() {
+    doubleGauge.getOrCreateTimeSeries(LABEL_VALUES);
+    assertThat(doubleGauge.getMetric(testClock))
+        .isEqualTo(
+            Metric.create(
+                METRIC_DESCRIPTOR,
+                Collections.singletonList(
+                    TimeSeries.createWithOnePoint(
+                        LABEL_VALUES, Point.create(Value.doubleValue(0), TEST_TIME), null))));
+
+    doubleGauge.removeTimeSeries(LABEL_VALUES);
+    assertThat(doubleGauge.getMetric(testClock)).isNull();
+  }
+
+  @Test
+  public void removeTimeSeries_WithNullLabelValues() {
+    thrown.expect(NullPointerException.class);
+    thrown.expectMessage("labelValues should not be null.");
+    doubleGauge.removeTimeSeries(null);
+  }
+
+  @Test
+  public void clear() {
+    DoublePoint doublePoint = doubleGauge.getOrCreateTimeSeries(LABEL_VALUES);
+    doublePoint.add(-11);
+    DoublePoint defaultPoint = doubleGauge.getDefaultTimeSeries();
+    defaultPoint.set(100);
+
+    Metric metric = doubleGauge.getMetric(testClock);
+    assertThat(metric).isNotNull();
+    assertThat(metric.getMetricDescriptor()).isEqualTo(METRIC_DESCRIPTOR);
+    assertThat(metric.getTimeSeriesList().size()).isEqualTo(2);
+
+    doubleGauge.clear();
+    assertThat(doubleGauge.getMetric(testClock)).isNull();
+  }
+
+  @Test
+  public void setDefaultLabelValues() {
+    List<LabelKey> labelKeys =
+        Arrays.asList(LabelKey.create("key1", "desc"), LabelKey.create("key2", "desc"));
+    DoubleGaugeImpl doubleGauge =
+        new DoubleGaugeImpl(METRIC_NAME, METRIC_DESCRIPTION, METRIC_UNIT, labelKeys);
+    DoublePoint defaultPoint = doubleGauge.getDefaultTimeSeries();
+    defaultPoint.set(-230);
+
+    Metric metric = doubleGauge.getMetric(testClock);
+    assertThat(metric).isNotNull();
+    assertThat(metric.getTimeSeriesList().size()).isEqualTo(1);
+    assertThat(metric.getTimeSeriesList().get(0).getLabelValues().size()).isEqualTo(2);
+    assertThat(metric.getTimeSeriesList().get(0).getLabelValues().get(0)).isEqualTo(UNSET_VALUE);
+    assertThat(metric.getTimeSeriesList().get(0).getLabelValues().get(1)).isEqualTo(UNSET_VALUE);
+  }
+
+  @Test
+  public void pointImpl_InstanceOf() {
+    DoublePoint doublePoint = doubleGauge.getOrCreateTimeSeries(LABEL_VALUES);
+    assertThat(doublePoint).isInstanceOf(DoubleGaugeImpl.PointImpl.class);
+  }
+
+  @Test
+  public void multipleMetrics_GetMetric() {
+    DoublePoint doublePoint = doubleGauge.getOrCreateTimeSeries(LABEL_VALUES);
+    doublePoint.add(1);
+    doublePoint.add(2);
+
+    DoublePoint defaultPoint = doubleGauge.getDefaultTimeSeries();
+    defaultPoint.set(100);
+
+    DoublePoint doublePoint1 = doubleGauge.getOrCreateTimeSeries(LABEL_VALUES1);
+    doublePoint1.add(-100);
+    doublePoint1.add(-20);
+
+    List<TimeSeries> expectedTimeSeriesList = new ArrayList<TimeSeries>();
+    expectedTimeSeriesList.add(
+        TimeSeries.createWithOnePoint(
+            LABEL_VALUES, Point.create(Value.doubleValue(3), TEST_TIME), null));
+    expectedTimeSeriesList.add(
+        TimeSeries.createWithOnePoint(
+            DEFAULT_LABEL_VALUES, Point.create(Value.doubleValue(100), TEST_TIME), null));
+    expectedTimeSeriesList.add(
+        TimeSeries.createWithOnePoint(
+            LABEL_VALUES1, Point.create(Value.doubleValue(-120), TEST_TIME), null));
+
+    Metric metric = doubleGauge.getMetric(testClock);
+    assertThat(metric).isNotNull();
+    assertThat(metric.getMetricDescriptor()).isEqualTo(METRIC_DESCRIPTOR);
+    assertThat(metric.getTimeSeriesList().size()).isEqualTo(3);
+    assertThat(metric.getTimeSeriesList()).containsExactlyElementsIn(expectedTimeSeriesList);
+  }
+
+  @Test
+  public void empty_GetMetrics() {
+    assertThat(doubleGauge.getMetric(testClock)).isNull();
+  }
+
+  @Test
+  public void testEquals() {
+    List<LabelKey> labelKeys =
+        Arrays.asList(LabelKey.create("key1", "desc"), LabelKey.create("key2", "desc"));
+    List<LabelValue> labelValues =
+        Arrays.asList(LabelValue.create("value1"), LabelValue.create("value2"));
+
+    DoubleGaugeImpl doubleGauge =
+        new DoubleGaugeImpl(METRIC_NAME, METRIC_DESCRIPTION, METRIC_UNIT, labelKeys);
+
+    DoublePoint defaultPoint1 = doubleGauge.getDefaultTimeSeries();
+    DoublePoint defaultPoint2 = doubleGauge.getDefaultTimeSeries();
+    DoublePoint doublePoint1 = doubleGauge.getOrCreateTimeSeries(labelValues);
+    DoublePoint doublePoint2 = doubleGauge.getOrCreateTimeSeries(labelValues);
+
+    new EqualsTester()
+        .addEqualityGroup(defaultPoint1, defaultPoint2)
+        .addEqualityGroup(doublePoint1, doublePoint2)
+        .testEquals();
+
+    doubleGauge.clear();
+
+    DoublePoint newDefaultPointAfterClear = doubleGauge.getDefaultTimeSeries();
+    DoublePoint newDoublePointAfterClear = doubleGauge.getOrCreateTimeSeries(labelValues);
+
+    doubleGauge.removeTimeSeries(labelValues);
+    DoublePoint newDoublePointAfterRemove = doubleGauge.getOrCreateTimeSeries(labelValues);
+
+    new EqualsTester()
+        .addEqualityGroup(defaultPoint1, defaultPoint2)
+        .addEqualityGroup(doublePoint1, doublePoint2)
+        .addEqualityGroup(newDefaultPointAfterClear)
+        .addEqualityGroup(newDoublePointAfterClear)
+        .addEqualityGroup(newDoublePointAfterRemove)
+        .testEquals();
+  }
+}
diff --git a/impl_core/src/test/java/io/opencensus/implcore/metrics/LongGaugeImplTest.java b/impl_core/src/test/java/io/opencensus/implcore/metrics/LongGaugeImplTest.java
index 81637c61..25797cff 100644
--- a/impl_core/src/test/java/io/opencensus/implcore/metrics/LongGaugeImplTest.java
+++ b/impl_core/src/test/java/io/opencensus/implcore/metrics/LongGaugeImplTest.java
@@ -104,14 +104,14 @@ public class LongGaugeImplTest {
     point1.set(500);
 
     Metric metric = longGaugeMetric.getMetric(testClock);
-    assertThat(metric).isNotEqualTo(null);
+    assertThat(metric).isNotNull();
     assertThat(metric)
         .isEqualTo(
             Metric.createWithOneTimeSeries(
                 METRIC_DESCRIPTOR,
                 TimeSeries.createWithOnePoint(
                     LABEL_VALUES, Point.create(Value.longValue(500), TEST_TIME), null)));
-    new EqualsTester().addEqualityGroup(point, point1).testEquals();
+    assertThat(point).isSameAs(point1);
   }
 
   @Test
@@ -121,7 +121,7 @@ public class LongGaugeImplTest {
     point.add(-33);
 
     Metric metric = longGaugeMetric.getMetric(testClock);
-    assertThat(metric).isNotEqualTo(null);
+    assertThat(metric).isNotNull();
     assertThat(metric.getMetricDescriptor()).isEqualTo(METRIC_DESCRIPTOR);
     assertThat(metric.getTimeSeriesList().size()).isEqualTo(1);
     assertThat(metric.getTimeSeriesList().get(0).getPoints().size()).isEqualTo(1);
@@ -129,7 +129,7 @@ public class LongGaugeImplTest {
         .isEqualTo(Value.longValue(-133));
     assertThat(metric.getTimeSeriesList().get(0).getPoints().get(0).getTimestamp())
         .isEqualTo(TEST_TIME);
-    assertThat(metric.getTimeSeriesList().get(0).getStartTimestamp()).isEqualTo(null);
+    assertThat(metric.getTimeSeriesList().get(0).getStartTimestamp()).isNull();
   }
 
   @Test
@@ -142,14 +142,14 @@ public class LongGaugeImplTest {
     point1.add(-100);
 
     Metric metric = longGaugeMetric.getMetric(testClock);
-    assertThat(metric).isNotEqualTo(null);
+    assertThat(metric).isNotNull();
     assertThat(metric)
         .isEqualTo(
             Metric.createWithOneTimeSeries(
                 METRIC_DESCRIPTOR,
                 TimeSeries.createWithOnePoint(
                     DEFAULT_LABEL_VALUES, Point.create(Value.longValue(400), TEST_TIME), null)));
-    new EqualsTester().addEqualityGroup(point, point1).testEquals();
+    assertThat(point).isSameAs(point1);
   }
 
   @Test
@@ -163,7 +163,7 @@ public class LongGaugeImplTest {
                     LABEL_VALUES, Point.create(Value.longValue(0), TEST_TIME), null)));
 
     longGaugeMetric.removeTimeSeries(LABEL_VALUES);
-    assertThat(longGaugeMetric.getMetric(testClock)).isEqualTo(null);
+    assertThat(longGaugeMetric.getMetric(testClock)).isNull();
   }
 
   @Test
@@ -181,12 +181,12 @@ public class LongGaugeImplTest {
     defaultPoint.set(100);
 
     Metric metric = longGaugeMetric.getMetric(testClock);
-    assertThat(metric).isNotEqualTo(null);
+    assertThat(metric).isNotNull();
     assertThat(metric.getMetricDescriptor()).isEqualTo(METRIC_DESCRIPTOR);
     assertThat(metric.getTimeSeriesList().size()).isEqualTo(2);
 
     longGaugeMetric.clear();
-    assertThat(longGaugeMetric.getMetric(testClock)).isEqualTo(null);
+    assertThat(longGaugeMetric.getMetric(testClock)).isNull();
   }
 
   @Test
@@ -199,7 +199,7 @@ public class LongGaugeImplTest {
     defaultPoint.set(-230);
 
     Metric metric = longGauge.getMetric(testClock);
-    assertThat(metric).isNotEqualTo(null);
+    assertThat(metric).isNotNull();
     assertThat(metric.getTimeSeriesList().size()).isEqualTo(1);
     assertThat(metric.getTimeSeriesList().get(0).getLabelValues().size()).isEqualTo(2);
     assertThat(metric.getTimeSeriesList().get(0).getLabelValues().get(0)).isEqualTo(UNSET_VALUE);
@@ -225,27 +225,27 @@ public class LongGaugeImplTest {
     longPoint1.add(-100);
     longPoint1.add(-20);
 
-    List<TimeSeries> timeSeriesList = new ArrayList<TimeSeries>();
-    timeSeriesList.add(
+    List<TimeSeries> expectedTimeSeriesList = new ArrayList<TimeSeries>();
+    expectedTimeSeriesList.add(
         TimeSeries.createWithOnePoint(
             LABEL_VALUES, Point.create(Value.longValue(3), TEST_TIME), null));
-    timeSeriesList.add(
+    expectedTimeSeriesList.add(
         TimeSeries.createWithOnePoint(
             DEFAULT_LABEL_VALUES, Point.create(Value.longValue(100), TEST_TIME), null));
-    timeSeriesList.add(
+    expectedTimeSeriesList.add(
         TimeSeries.createWithOnePoint(
             LABEL_VALUES1, Point.create(Value.longValue(-120), TEST_TIME), null));
 
     Metric metric = longGaugeMetric.getMetric(testClock);
-    assertThat(metric).isNotEqualTo(null);
+    assertThat(metric).isNotNull();
     assertThat(metric.getMetricDescriptor()).isEqualTo(METRIC_DESCRIPTOR);
     assertThat(metric.getTimeSeriesList().size()).isEqualTo(3);
-    assertThat(metric.getTimeSeriesList()).containsExactlyElementsIn(timeSeriesList);
+    assertThat(metric.getTimeSeriesList()).containsExactlyElementsIn(expectedTimeSeriesList);
   }
 
   @Test
   public void empty_GetMetrics() {
-    assertThat(longGaugeMetric.getMetric(testClock)).isEqualTo(null);
+    assertThat(longGaugeMetric.getMetric(testClock)).isNull();
   }
 
   @Test