Metrics: Combine TimeSeriesCumulative and TimeSeriesGauge. (#1380)

5 files changed, 85 insertions, 287 deletions

diff --git a/api/src/main/java/io/opencensus/metrics/Metric.java b/api/src/main/java/io/opencensus/metrics/Metric.java
index e8be0b90..9cbd418b 100644
--- a/api/src/main/java/io/opencensus/metrics/Metric.java
+++ b/api/src/main/java/io/opencensus/metrics/Metric.java
@@ -19,8 +19,10 @@ package io.opencensus.metrics;
 import com.google.auto.value.AutoValue;
 import io.opencensus.common.ExperimentalApi;
 import io.opencensus.internal.Utils;
-import io.opencensus.metrics.TimeSeriesList.TimeSeriesCumulativeList;
-import io.opencensus.metrics.TimeSeriesList.TimeSeriesGaugeList;
+import io.opencensus.metrics.Value.ValueDistribution;
+import io.opencensus.metrics.Value.ValueDouble;
+import io.opencensus.metrics.Value.ValueLong;
+import java.util.List;
 import javax.annotation.concurrent.Immutable;
 
 /**
@@ -39,11 +41,11 @@ public abstract class Metric {
    * Creates a {@link Metric}.
    *
    * @param metricDescriptor the {@link MetricDescriptor}.
-   * @param timeSeriesList the {@link TimeSeriesList} for this metric.
+   * @param timeSeriesList the {@link TimeSeries} list for this metric.
    * @return a {@code Metric}.
    * @since 0.16
    */
-  public static Metric create(MetricDescriptor metricDescriptor, TimeSeriesList timeSeriesList) {
+  public static Metric create(MetricDescriptor metricDescriptor, List<TimeSeries> timeSeriesList) {
     checkTypeMatch(metricDescriptor.getType(), timeSeriesList);
     return new AutoValue_Metric(metricDescriptor, timeSeriesList);
   }
@@ -57,32 +59,43 @@ public abstract class Metric {
   public abstract MetricDescriptor getMetricDescriptor();
 
   /**
-   * Returns the {@link TimeSeriesList} for this metric.
+   * Returns the {@link TimeSeries} list for this metric.
    *
-   * <p>The type of the {@link TimeSeriesList} must match {@link MetricDescriptor.Type}.
+   * <p>The type of the {@link TimeSeries#getPoints()} must match {@link MetricDescriptor.Type}.
    *
    * @return the {@code TimeSeriesList} for this metric.
    * @since 0.16
    */
-  public abstract TimeSeriesList getTimeSeriesList();
+  public abstract List<TimeSeries> getTimeSeriesList();
 
-  private static void checkTypeMatch(MetricDescriptor.Type type, TimeSeriesList timeSeriesList) {
-    switch (type) {
-      case GAUGE_INT64:
-      case GAUGE_DOUBLE:
-        Utils.checkArgument(
-            timeSeriesList instanceof TimeSeriesGaugeList,
-            String.format(
-                "Type mismatch: %s, %s.", type, timeSeriesList.getClass().getSimpleName()));
-        break;
-      case CUMULATIVE_DISTRIBUTION:
-      case CUMULATIVE_DOUBLE:
-      case CUMULATIVE_INT64:
-        Utils.checkArgument(
-            timeSeriesList instanceof TimeSeriesCumulativeList,
-            String.format(
-                "Type mismatch: %s, %s.", type, timeSeriesList.getClass().getSimpleName()));
-        break;
+  private static void checkTypeMatch(MetricDescriptor.Type type, List<TimeSeries> timeSeriesList) {
+    for (TimeSeries timeSeries : timeSeriesList) {
+      for (Point point : timeSeries.getPoints()) {
+        Value value = point.getValue();
+        String valueClassName = "";
+        if (value.getClass().getSuperclass() != null) { // work around nullness check
+          // AutoValue classes should always have a super class.
+          valueClassName = value.getClass().getSuperclass().getSimpleName();
+        }
+        switch (type) {
+          case GAUGE_INT64:
+          case CUMULATIVE_INT64:
+            Utils.checkArgument(
+                value instanceof ValueLong,
+                String.format("Type mismatch: %s, %s.", type, valueClassName));
+            break;
+          case CUMULATIVE_DOUBLE:
+          case GAUGE_DOUBLE:
+            Utils.checkArgument(
+                value instanceof ValueDouble,
+                String.format("Type mismatch: %s, %s.", type, valueClassName));
+            break;
+          case CUMULATIVE_DISTRIBUTION:
+            Utils.checkArgument(
+                value instanceof ValueDistribution,
+                String.format("Type mismatch: %s, %s.", type, valueClassName));
+        }
+      }
     }
   }
 }
diff --git a/api/src/main/java/io/opencensus/metrics/TimeSeries.java b/api/src/main/java/io/opencensus/metrics/TimeSeries.java
index bbbfe0e4..c62b6b72 100644
--- a/api/src/main/java/io/opencensus/metrics/TimeSeries.java
+++ b/api/src/main/java/io/opencensus/metrics/TimeSeries.java
@@ -16,16 +16,52 @@
 
 package io.opencensus.metrics;
 
+import com.google.auto.value.AutoValue;
+import io.opencensus.common.ExperimentalApi;
+import io.opencensus.common.Timestamp;
+import io.opencensus.internal.Utils;
+import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
+import javax.annotation.Nullable;
 import javax.annotation.concurrent.Immutable;
 
-/** A collection of data points that describes the time-varying values of a {@code Metric}. */
+/**
+ * A collection of data points that describes the time-varying values of a {@code Metric}.
+ *
+ * @since 0.16
+ */
+@ExperimentalApi
 @Immutable
-abstract class TimeSeries {
+@AutoValue
+public abstract class TimeSeries {
 
   TimeSeries() {}
 
   /**
+   * Creates a {@link TimeSeries}.
+   *
+   * @param labelValues the {@code LabelValue}s that uniquely identify this {@code TimeSeries}.
+   * @param points the data {@code Point}s of this {@code TimeSeries}.
+   * @param startTimestamp the start {@code Timestamp} of this {@code TimeSeries}. Must be non-null
+   *     for cumulative {@code Point}s.
+   * @return a {@code TimeSeries}.
+   * @since 0.16
+   */
+  public static TimeSeries create(
+      List<LabelValue> labelValues, List<Point> points, @Nullable Timestamp startTimestamp) {
+    // Fail fast on null lists to prevent NullPointerException when copying the lists.
+    Utils.checkNotNull(labelValues, "labelValues");
+    Utils.checkNotNull(points, "points");
+    Utils.checkListElementNotNull(labelValues, "labelValue");
+    Utils.checkListElementNotNull(points, "point");
+    return new AutoValue_TimeSeries(
+        Collections.unmodifiableList(new ArrayList<LabelValue>(labelValues)),
+        Collections.unmodifiableList(new ArrayList<Point>(points)),
+        startTimestamp);
+  }
+
+  /**
    * Returns the set of {@link LabelValue}s that uniquely identify this {@link TimeSeries}.
    *
    * <p>Apply to all {@link Point}s.
@@ -45,4 +81,14 @@ abstract class TimeSeries {
    * @since 0.16
    */
   public abstract List<Point> getPoints();
+
+  /**
+   * Returns the start {@link Timestamp} of this {@link TimeSeries} if the {@link Point}s are
+   * cumulative, or {@code null} if the {@link Point}s are gauge.
+   *
+   * @return the start {@code Timestamp} or {@code null}.
+   * @since 0.16
+   */
+  @Nullable
+  public abstract Timestamp getStartTimestamp();
 }
diff --git a/api/src/main/java/io/opencensus/metrics/TimeSeriesCumulative.java b/api/src/main/java/io/opencensus/metrics/TimeSeriesCumulative.java
deleted file mode 100644
index 5f48b770..00000000
--- a/api/src/main/java/io/opencensus/metrics/TimeSeriesCumulative.java
+++ /dev/null
@@ -1,70 +0,0 @@
-/*
- * 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.metrics;
-
-import com.google.auto.value.AutoValue;
-import io.opencensus.common.ExperimentalApi;
-import io.opencensus.common.Timestamp;
-import io.opencensus.internal.Utils;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.List;
-import javax.annotation.concurrent.Immutable;
-
-/**
- * A collection of data points that describes the time-varying values of a cumulative {@code
- * Metric}.
- *
- * @since 0.16
- */
-@ExperimentalApi
-@Immutable
-@AutoValue
-public abstract class TimeSeriesCumulative extends TimeSeries {
-
-  TimeSeriesCumulative() {}
-
-  /**
-   * Creates a {@link TimeSeriesCumulative}.
-   *
-   * @param labelValues the {@code LabelValue}s that uniquely identify this {@code TimeSeries}.
-   * @param points the data {@code Point}s of this {@code TimeSeries}.
-   * @param startTimestamp the start {@code Timestamp} of this {@code TimeSeriesCumulative}.
-   * @return a {@code TimeSeriesCumulative}.
-   * @since 0.16
-   */
-  public static TimeSeriesCumulative create(
-      List<LabelValue> labelValues, List<Point> points, Timestamp startTimestamp) {
-    // Fail fast on null lists to prevent NullPointerException when copying the lists.
-    Utils.checkNotNull(labelValues, "labelValues");
-    Utils.checkNotNull(points, "points");
-    Utils.checkListElementNotNull(labelValues, "labelValue");
-    Utils.checkListElementNotNull(points, "point");
-    return new AutoValue_TimeSeriesCumulative(
-        Collections.unmodifiableList(new ArrayList<LabelValue>(labelValues)),
-        Collections.unmodifiableList(new ArrayList<Point>(points)),
-        startTimestamp);
-  }
-
-  /**
-   * Returns the start {@link Timestamp} of this {@link TimeSeriesCumulative}.
-   *
-   * @return the start {@code Timestamp}.
-   * @since 0.16
-   */
-  public abstract Timestamp getStartTimestamp();
-}
diff --git a/api/src/main/java/io/opencensus/metrics/TimeSeriesGauge.java b/api/src/main/java/io/opencensus/metrics/TimeSeriesGauge.java
deleted file mode 100644
index 717505a4..00000000
--- a/api/src/main/java/io/opencensus/metrics/TimeSeriesGauge.java
+++ /dev/null
@@ -1,57 +0,0 @@
-/*
- * 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.metrics;
-
-import com.google.auto.value.AutoValue;
-import io.opencensus.common.ExperimentalApi;
-import io.opencensus.internal.Utils;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.List;
-import javax.annotation.concurrent.Immutable;
-
-/**
- * A collection of data points that describes the time-varying values of a gauge {@code Metric}.
- *
- * @since 0.16
- */
-@ExperimentalApi
-@Immutable
-@AutoValue
-public abstract class TimeSeriesGauge extends TimeSeries {
-
-  TimeSeriesGauge() {}
-
-  /**
-   * Creates a {@link TimeSeriesGauge}.
-   *
-   * @param labelValues the {@code LabelValue}s that uniquely identify this {@code TimeSeries}.
-   * @param points the data {@code Point}s of this {@code TimeSeries}.
-   * @return a {@code TimeSeriesGauge}.
-   * @since 0.16
-   */
-  public static TimeSeriesGauge create(List<LabelValue> labelValues, List<Point> points) {
-    // Fail fast on null lists to prevent NullPointerException when copying the lists.
-    Utils.checkNotNull(labelValues, "labelValues");
-    Utils.checkNotNull(points, "points");
-    Utils.checkListElementNotNull(labelValues, "labelValue");
-    Utils.checkListElementNotNull(points, "point");
-    return new AutoValue_TimeSeriesGauge(
-        Collections.unmodifiableList(new ArrayList<LabelValue>(labelValues)),
-        Collections.unmodifiableList(new ArrayList<Point>(points)));
-  }
-}
diff --git a/api/src/main/java/io/opencensus/metrics/TimeSeriesList.java b/api/src/main/java/io/opencensus/metrics/TimeSeriesList.java
deleted file mode 100644
index 6138eac2..00000000
--- a/api/src/main/java/io/opencensus/metrics/TimeSeriesList.java
+++ /dev/null
@@ -1,134 +0,0 @@
-/*
- * 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.metrics;
-
-import com.google.auto.value.AutoValue;
-import io.opencensus.common.ExperimentalApi;
-import io.opencensus.common.Function;
-import io.opencensus.internal.Utils;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.List;
-import javax.annotation.concurrent.Immutable;
-
-/**
- * Class that holds a list of either {@link TimeSeriesGauge} or {@link TimeSeriesCumulative}.
- *
- * @since 0.16
- */
-@ExperimentalApi
-@Immutable
-public abstract class TimeSeriesList {
-
-  TimeSeriesList() {}
-
-  /**
-   * Applies the given match function to the underlying data type.
-   *
-   * @since 0.16
-   */
-  public abstract <T> T match(
-      Function<? super TimeSeriesGaugeList, T> gaugeListFunction,
-      Function<? super TimeSeriesCumulativeList, T> cumulativeListFunction,
-      Function<? super TimeSeriesList, T> defaultFunction);
-
-  /**
-   * Class that holds a list of {@link TimeSeriesGauge}.
-   *
-   * @since 0.16
-   */
-  @ExperimentalApi
-  @Immutable
-  @AutoValue
-  public abstract static class TimeSeriesGaugeList extends TimeSeriesList {
-
-    TimeSeriesGaugeList() {}
-
-    @Override
-    public final <T> T match(
-        Function<? super TimeSeriesGaugeList, T> gaugeListFunction,
-        Function<? super TimeSeriesCumulativeList, T> cumulativeListFunction,
-        Function<? super TimeSeriesList, T> defaultFunction) {
-      return gaugeListFunction.apply(this);
-    }
-
-    /**
-     * Creates a {@link TimeSeriesGaugeList}.
-     *
-     * @param list a list of {@link TimeSeriesGauge}.
-     * @return a {code TimeSeriesGaugeList}.
-     * @since 0.16
-     */
-    public static TimeSeriesGaugeList create(List<TimeSeriesGauge> list) {
-      Utils.checkNotNull(list, "list");
-      Utils.checkListElementNotNull(list, "timeSeriesGauge");
-      return new AutoValue_TimeSeriesList_TimeSeriesGaugeList(
-          Collections.unmodifiableList(new ArrayList<TimeSeriesGauge>(list)));
-    }
-
-    /**
-     * Returns the list of {@link TimeSeriesGauge}.
-     *
-     * @return the list of {@code TimeSeriesGauge}.
-     * @since 0.16
-     */
-    public abstract List<TimeSeriesGauge> getList();
-  }
-
-  /**
-   * Class that holds a list of {@link TimeSeriesCumulative}.
-   *
-   * @since 0.16
-   */
-  @ExperimentalApi
-  @Immutable
-  @AutoValue
-  public abstract static class TimeSeriesCumulativeList extends TimeSeriesList {
-
-    TimeSeriesCumulativeList() {}
-
-    @Override
-    public final <T> T match(
-        Function<? super TimeSeriesGaugeList, T> gaugeListFunction,
-        Function<? super TimeSeriesCumulativeList, T> cumulativeListFunction,
-        Function<? super TimeSeriesList, T> defaultFunction) {
-      return cumulativeListFunction.apply(this);
-    }
-
-    /**
-     * Creates a {@link TimeSeriesCumulativeList}.
-     *
-     * @param list a list of {@link TimeSeriesCumulative}.
-     * @return a {code TimeSeriesCumulativeList}.
-     * @since 0.16
-     */
-    public static TimeSeriesCumulativeList create(List<TimeSeriesCumulative> list) {
-      Utils.checkNotNull(list, "list");
-      Utils.checkListElementNotNull(list, "timeSeriesCumulative");
-      return new AutoValue_TimeSeriesList_TimeSeriesCumulativeList(
-          Collections.unmodifiableList(new ArrayList<TimeSeriesCumulative>(list)));
-    }
-
-    /**
-     * Returns the list of {@link TimeSeriesCumulative}.
-     *
-     * @return the list of {@code TimeSeriesCumulative}.
-     * @since 0.16
-     */
-    public abstract List<TimeSeriesCumulative> getList();
-  }
-}