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

* Metrics: Move to api.

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

1 files changed, 128 insertions, 0 deletions

diff --git a/api/src/test/java/io/opencensus/metrics/ValueTest.java b/api/src/test/java/io/opencensus/metrics/ValueTest.java
new file mode 100644
index 00000000..63430b28
--- /dev/null
+++ b/api/src/test/java/io/opencensus/metrics/ValueTest.java
@@ -0,0 +1,128 @@
+/*
+ * 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.Function;
+import io.opencensus.common.Functions;
+import io.opencensus.metrics.Distribution.Bucket;
+import io.opencensus.metrics.Value.ValueDistribution;
+import io.opencensus.metrics.Value.ValueDouble;
+import io.opencensus.metrics.Value.ValueLong;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+/** Unit tests for {@link Value}. */
+@RunWith(JUnit4.class)
+public class ValueTest {
+
+  private static final Distribution DISTRIBUTION =
+      Distribution.create(
+          10,
+          10,
+          1,
+          Arrays.asList(-5.0, 0.0, 5.0),
+          Arrays.asList(Bucket.create(3), Bucket.create(1), Bucket.create(2), Bucket.create(4)));
+
+  @Test
+  public void createAndGet_ValueDouble() {
+    Value value = Value.doubleValue(-34.56);
+    assertThat(value).isInstanceOf(ValueDouble.class);
+    assertThat(((ValueDouble) value).getValue()).isEqualTo(-34.56);
+  }
+
+  @Test
+  public void createAndGet_ValueLong() {
+    Value value = Value.longValue(123456789);
+    assertThat(value).isInstanceOf(ValueLong.class);
+    assertThat(((ValueLong) value).getValue()).isEqualTo(123456789);
+  }
+
+  @Test
+  public void createAndGet_ValueDistribution() {
+    Value value = Value.distributionValue(DISTRIBUTION);
+    assertThat(value).isInstanceOf(ValueDistribution.class);
+    assertThat(((ValueDistribution) value).getValue()).isEqualTo(DISTRIBUTION);
+  }
+
+  @Test
+  public void testEquals() {
+    new EqualsTester()
+        .addEqualityGroup(Value.doubleValue(1.0), Value.doubleValue(1.0))
+        .addEqualityGroup(Value.doubleValue(2.0))
+        .addEqualityGroup(Value.longValue(1L))
+        .addEqualityGroup(Value.longValue(2L))
+        .addEqualityGroup(
+            Value.distributionValue(
+                Distribution.create(
+                    -7,
+                    10,
+                    23.456,
+                    Arrays.asList(-5.0, 0.0, 5.0),
+                    Arrays.asList(
+                        Bucket.create(3), Bucket.create(1), Bucket.create(2), Bucket.create(4)))))
+        .testEquals();
+  }
+
+  @Test
+  public void testMatch() {
+    List<Value> values =
+        Arrays.asList(
+            ValueDouble.create(1.0), ValueLong.create(-1), ValueDistribution.create(DISTRIBUTION));
+    List<Number> expected =
+        Arrays.<Number>asList(1.0, -1L, 10.0, 10L, 1.0, -5.0, 0.0, 5.0, 3L, 1L, 2L, 4L);
+    final List<Number> actual = new ArrayList<Number>();
+    for (Value value : values) {
+      value.match(
+          new Function<Double, Object>() {
+            @Override
+            public Object apply(Double arg) {
+              actual.add(arg);
+              return null;
+            }
+          },
+          new Function<Long, Object>() {
+            @Override
+            public Object apply(Long arg) {
+              actual.add(arg);
+              return null;
+            }
+          },
+          new Function<Distribution, Object>() {
+            @Override
+            public Object apply(Distribution arg) {
+              actual.add(arg.getMean());
+              actual.add(arg.getCount());
+              actual.add(arg.getSumOfSquaredDeviations());
+              actual.addAll(arg.getBucketBoundaries());
+              for (Bucket bucket : arg.getBuckets()) {
+                actual.add(bucket.getCount());
+              }
+              return null;
+            }
+          },
+          Functions.throwAssertionError());
+    }
+    assertThat(actual).containsExactlyElementsIn(expected).inOrder();
+  }
+}