Metrics: Move metrics to opencensus-api. (#1346)

* Metrics: Move to api.

* Update package-info to warn users on using metrics.

1 files changed, 127 insertions, 0 deletions

diff --git a/api/src/test/java/io/opencensus/metrics/MetricTest.java b/api/src/test/java/io/opencensus/metrics/MetricTest.java
new file mode 100644
index 00000000..59838ef4
--- /dev/null
+++ b/api/src/test/java/io/opencensus/metrics/MetricTest.java
@@ -0,0 +1,127 @@
+/*
+ * 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 static com.google.common.truth.Truth.assertThat;
+
+import com.google.common.testing.EqualsTester;
+import io.opencensus.common.Timestamp;
+import io.opencensus.metrics.MetricDescriptor.Type;
+import io.opencensus.metrics.TimeSeriesList.TimeSeriesCumulativeList;
+import io.opencensus.metrics.TimeSeriesList.TimeSeriesGaugeList;
+import java.util.Arrays;
+import java.util.Collections;
+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 Metric}. */
+@RunWith(JUnit4.class)
+public class MetricTest {
+
+  @Rule public final ExpectedException thrown = ExpectedException.none();
+
+  private static final String METRIC_NAME_1 = "metric1";
+  private static final String METRIC_NAME_2 = "metric2";
+  private static final String DESCRIPTION = "Metric description.";
+  private static final String UNIT = "kb/s";
+  private static final LabelKey KEY_1 = LabelKey.create("key1", "some key");
+  private static final LabelKey KEY_2 = LabelKey.create("key1", "some other key");
+  private static final MetricDescriptor METRIC_DESCRIPTOR_1 =
+      MetricDescriptor.create(
+          METRIC_NAME_1, DESCRIPTION, UNIT, Type.GAUGE_DOUBLE, Arrays.asList(KEY_1, KEY_2));
+  private static final MetricDescriptor METRIC_DESCRIPTOR_2 =
+      MetricDescriptor.create(
+          METRIC_NAME_2, DESCRIPTION, UNIT, Type.CUMULATIVE_INT64, Arrays.asList(KEY_1));
+  private static final LabelValue LABEL_VALUE_1 = LabelValue.create("value1");
+  private static final LabelValue LABEL_VALUE_2 = LabelValue.create("value1");
+  private static final LabelValue LABEL_VALUE_EMPTY = LabelValue.create("");
+  private static final Value VALUE_LONG = Value.longValue(12345678);
+  private static final Value VALUE_DOUBLE_1 = Value.doubleValue(-345.77);
+  private static final Value VALUE_DOUBLE_2 = Value.doubleValue(133.79);
+  private static final Timestamp TIMESTAMP_1 = Timestamp.fromMillis(1000);
+  private static final Timestamp TIMESTAMP_2 = Timestamp.fromMillis(2000);
+  private static final Timestamp TIMESTAMP_3 = Timestamp.fromMillis(3000);
+  private static final Point POINT_1 = Point.create(VALUE_DOUBLE_1, TIMESTAMP_2);
+  private static final Point POINT_2 = Point.create(VALUE_DOUBLE_2, TIMESTAMP_3);
+  private static final Point POINT_3 = Point.create(VALUE_LONG, TIMESTAMP_3);
+  private static final TimeSeriesGauge GAUGE_TIME_SERIES_1 =
+      TimeSeriesGauge.create(Arrays.asList(LABEL_VALUE_1, LABEL_VALUE_2), Arrays.asList(POINT_1));
+  private static final TimeSeriesGauge GAUGE_TIME_SERIES_2 =
+      TimeSeriesGauge.create(Arrays.asList(LABEL_VALUE_1, LABEL_VALUE_2), Arrays.asList(POINT_2));
+  private static final TimeSeriesCumulative CUMULATIVE_TIME_SERIES =
+      TimeSeriesCumulative.create(
+          Arrays.asList(LABEL_VALUE_EMPTY), Arrays.asList(POINT_3), TIMESTAMP_1);
+  private static final TimeSeriesGaugeList TIME_SERIES_GAUGE_LIST =
+      TimeSeriesGaugeList.create(Arrays.asList(GAUGE_TIME_SERIES_1, GAUGE_TIME_SERIES_2));
+  private static final TimeSeriesCumulativeList TIME_SERIES_CUMULATIVE_LIST =
+      TimeSeriesCumulativeList.create(Arrays.asList(CUMULATIVE_TIME_SERIES));
+
+  @Test
+  public void testGet() {
+    Metric metric = Metric.create(METRIC_DESCRIPTOR_1, TIME_SERIES_GAUGE_LIST);
+    assertThat(metric.getMetricDescriptor()).isEqualTo(METRIC_DESCRIPTOR_1);
+    assertThat(metric.getTimeSeriesList()).isEqualTo(TIME_SERIES_GAUGE_LIST);
+  }
+
+  @Test
+  public void typeMismatch_GaugeDouble_TimeSeriesCumulative() {
+    typeMismatch(
+        METRIC_DESCRIPTOR_1,
+        TIME_SERIES_CUMULATIVE_LIST,
+        String.format(
+            "Type mismatch: %s, %s.",
+            Type.GAUGE_DOUBLE, TIME_SERIES_CUMULATIVE_LIST.getClass().getSimpleName()));
+  }
+
+  @Test
+  public void typeMismatch_CumulativeInt64_TimeSeriesGauge() {
+    typeMismatch(
+        METRIC_DESCRIPTOR_2,
+        TIME_SERIES_GAUGE_LIST,
+        String.format(
+            "Type mismatch: %s, %s.",
+            Type.CUMULATIVE_INT64, TIME_SERIES_GAUGE_LIST.getClass().getSimpleName()));
+  }
+
+  private void typeMismatch(
+      MetricDescriptor metricDescriptor, TimeSeriesList timeSeriesList, String errorMessage) {
+    thrown.expect(IllegalArgumentException.class);
+    thrown.expectMessage(errorMessage);
+    Metric.create(metricDescriptor, timeSeriesList);
+  }
+
+  @Test
+  public void testEquals() {
+    new EqualsTester()
+        .addEqualityGroup(
+            Metric.create(METRIC_DESCRIPTOR_1, TIME_SERIES_GAUGE_LIST),
+            Metric.create(METRIC_DESCRIPTOR_1, TIME_SERIES_GAUGE_LIST))
+        .addEqualityGroup(
+            Metric.create(
+                METRIC_DESCRIPTOR_1,
+                TimeSeriesGaugeList.create(Collections.<TimeSeriesGauge>emptyList())))
+        .addEqualityGroup(Metric.create(METRIC_DESCRIPTOR_2, TIME_SERIES_CUMULATIVE_LIST))
+        .addEqualityGroup(
+            Metric.create(
+                METRIC_DESCRIPTOR_2,
+                TimeSeriesCumulativeList.create(Collections.<TimeSeriesCumulative>emptyList())))
+        .testEquals();
+  }
+}