diff options
Diffstat (limited to 'api')
4 files changed, 247 insertions, 4 deletions
diff --git a/api/src/main/java/io/opencensus/common/ToLongFunction.java b/api/src/main/java/io/opencensus/common/ToLongFunction.java index 26a27b18..cd2b68ed 100644 --- a/api/src/main/java/io/opencensus/common/ToLongFunction.java +++ b/api/src/main/java/io/opencensus/common/ToLongFunction.java @@ -16,6 +16,10 @@ package io.opencensus.common; +/*>>> +import org.checkerframework.checker.nullness.qual.Nullable; +*/ + /** * Represents a function that produces a long-valued result. See {@link * io.opencensus.metrics.MetricRegistry} for an example of its use. @@ -25,12 +29,12 @@ package io.opencensus.common; * * @since 0.16 */ -public interface ToLongFunction<T> { +public interface ToLongFunction</*@Nullable*/ T> { /** * Applies this function to the given argument. * * @param value the function argument. * @return the function result. */ - long applyAsLong(T value); + long applyAsLong(/*@Nullable*/ T value); } diff --git a/api/src/main/java/io/opencensus/metrics/DerivedLongGauge.java b/api/src/main/java/io/opencensus/metrics/DerivedLongGauge.java new file mode 100644 index 00000000..8fdd800d --- /dev/null +++ b/api/src/main/java/io/opencensus/metrics/DerivedLongGauge.java @@ -0,0 +1,151 @@ +/* + * 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 io.opencensus.common.ToLongFunction; +import io.opencensus.internal.Utils; +import java.lang.ref.WeakReference; +import java.util.List; +import javax.annotation.concurrent.ThreadSafe; + +/*>>> +import org.checkerframework.checker.nullness.qual.Nullable; +*/ + +/** + * Derived Long Gauge metric, to report instantaneous measurement of an int64 value. Gauges can go + * both up and down. The gauges values can be negative. + * + * <p>Example: Create a Gauge with object and function. + * + * <pre>{@code + * class YourClass { + * + * private static final MetricRegistry metricRegistry = Metrics.getMetricRegistry(); + * + * List<LabelKey> labelKeys = Arrays.asList(LabelKey.create("Name", "desc")); + * List<LabelValue> labelValues = Arrays.asList(LabelValue.create("Inbound")); + * + * // TODO(mayurkale): Plugs-in the DerivedLongGauge into the registry. + * DerivedLongGauge gauge = metricRegistry.addDerivedLongGauge( + * "queue_size", "Pending jobs in a queue", "1", labelKeys); + * + * QueueManager queueManager = new QueueManager(); + * gauge.createTimeSeries(labelValues, queueManager, + * new ToLongFunction<QueueManager>() { + * {@literal @}Override + * public long applyAsLong(QueueManager queue) { + * return queue.size(); + * } + * }); + * + * void doWork() { + * // Your code here. + * } + * } + * + * }</pre> + * + * @since 0.17 + */ +@ThreadSafe +public abstract class DerivedLongGauge { + /** + * Creates a {@code TimeSeries}. The value of a single point in the TimeSeries is observed from a + * callback function. This function is invoked whenever metrics are collected, meaning the + * reported value is up-to-date. It keeps a {@link WeakReference} to the object and it is the + * user's responsibility to manage the lifetime of the object. + * + * @param labelValues the list of label values. + * @param obj the state object from which the function derives a measurement. + * @param function the function to be called. + * @param <T> the type of the object upon which the function derives a measurement. + * @throws NullPointerException if {@code labelValues} is null OR any element of {@code + * labelValues} is null OR {@code function} is null. + * @throws IllegalArgumentException if different time series with the same labels already exists + * OR if number of {@code labelValues}s are not equal to the label keys. + * @since 0.17 + */ + public abstract <T> void createTimeSeries( + List<LabelValue> labelValues, /*@Nullable*/ T obj, ToLongFunction</*@Nullable*/ T> function); + + /** + * Removes the {@code TimeSeries} from the gauge metric, if it is present. + * + * @param labelValues the list of label values. + * @throws NullPointerException if {@code labelValues} is null. + * @since 0.17 + */ + public abstract void removeTimeSeries(List<LabelValue> labelValues); + + /** + * Removes all {@code TimeSeries} from the gauge metric. + * + * @since 0.17 + */ + public abstract void clear(); + + /** + * Returns the no-op implementation of the {@code DerivedLongGauge}. + * + * @return the no-op implementation of the {@code DerivedLongGauge}. + * @since 0.17 + */ + static DerivedLongGauge newNoopDerivedLongGauge( + String name, String description, String unit, List<LabelKey> labelKeys) { + return NoopDerivedLongGauge.create(name, description, unit, labelKeys); + } + + /** No-op implementations of DerivedLongGauge class. */ + private static final class NoopDerivedLongGauge extends DerivedLongGauge { + private final int labelKeysSize; + + static NoopDerivedLongGauge create( + String name, String description, String unit, List<LabelKey> labelKeys) { + return new NoopDerivedLongGauge(name, description, unit, labelKeys); + } + + /** Creates a new {@code NoopDerivedLongGauge}. */ + NoopDerivedLongGauge(String name, String description, String unit, List<LabelKey> labelKeys) { + Utils.checkNotNull(name, "name"); + Utils.checkNotNull(description, "description"); + Utils.checkNotNull(unit, "unit"); + Utils.checkListElementNotNull( + Utils.checkNotNull(labelKeys, "labelKeys"), "labelKey element should not be null."); + labelKeysSize = labelKeys.size(); + } + + @Override + public <T> void createTimeSeries( + List<LabelValue> labelValues, /*@Nullable*/ + T obj, + ToLongFunction</*@Nullable*/ T> function) { + Utils.checkListElementNotNull( + Utils.checkNotNull(labelValues, "labelValues"), "labelValue element should not be null."); + Utils.checkArgument(labelKeysSize == labelValues.size(), "Incorrect number of labels."); + Utils.checkNotNull(function, "function"); + } + + @Override + public void removeTimeSeries(List<LabelValue> labelValues) { + Utils.checkNotNull(labelValues, "labelValues"); + } + + @Override + public void clear() {} + } +} diff --git a/api/src/main/java/io/opencensus/metrics/LongGauge.java b/api/src/main/java/io/opencensus/metrics/LongGauge.java index 8ca760be..1d4489c9 100644 --- a/api/src/main/java/io/opencensus/metrics/LongGauge.java +++ b/api/src/main/java/io/opencensus/metrics/LongGauge.java @@ -106,8 +106,7 @@ public abstract class LongGauge { * previous {@code LongPoint} objects are invalid (not part of the metric). * * @param labelValues the list of label values. - * @throws NullPointerException if {@code labelValues} is null or any element of {@code - * labelValues} is null. + * @throws NullPointerException if {@code labelValues} is null. * @since 0.17 */ public abstract void removeTimeSeries(List<LabelValue> labelValues); diff --git a/api/src/test/java/io/opencensus/metrics/DerivedLongGaugeTest.java b/api/src/test/java/io/opencensus/metrics/DerivedLongGaugeTest.java new file mode 100644 index 00000000..6a462881 --- /dev/null +++ b/api/src/test/java/io/opencensus/metrics/DerivedLongGaugeTest.java @@ -0,0 +1,89 @@ +/* + * 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 io.opencensus.common.ToLongFunction; +import java.util.ArrayList; +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 DerivedLongGauge}. */ +// TODO(mayurkale): Add more tests, once DerivedLongGauge plugs-in into the registry. +@RunWith(JUnit4.class) +public class DerivedLongGaugeTest { + @Rule public ExpectedException thrown = ExpectedException.none(); + + private static final String NAME = "name"; + private static final String DESCRIPTION = "description"; + private static final String 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> EMPTY_LABEL_VALUES = new ArrayList<LabelValue>(); + + private final DerivedLongGauge derivedLongGauge = + DerivedLongGauge.newNoopDerivedLongGauge(NAME, DESCRIPTION, UNIT, LABEL_KEY); + private static final ToLongFunction<Object> longFunction = + new ToLongFunction<Object>() { + @Override + public long applyAsLong(Object value) { + return 5; + } + }; + + @Test + public void noopCreateTimeSeries_WithNullLabelValues() { + thrown.expect(NullPointerException.class); + thrown.expectMessage("labelValues"); + derivedLongGauge.createTimeSeries(null, null, longFunction); + } + + @Test + public void noopCreateTimeSeries_WithNullElement() { + List<LabelValue> labelValues = Collections.singletonList(null); + thrown.expect(NullPointerException.class); + thrown.expectMessage("labelValue element should not be null."); + derivedLongGauge.createTimeSeries(labelValues, null, longFunction); + } + + @Test + public void noopCreateTimeSeries_WithInvalidLabelSize() { + thrown.expect(IllegalArgumentException.class); + thrown.expectMessage("Incorrect number of labels."); + derivedLongGauge.createTimeSeries(EMPTY_LABEL_VALUES, null, longFunction); + } + + @Test + public void createTimeSeries_WithNullFunction() { + thrown.expect(NullPointerException.class); + thrown.expectMessage("function"); + derivedLongGauge.createTimeSeries(LABEL_VALUES, null, null); + } + + @Test + public void noopRemoveTimeSeries_WithNullLabelValues() { + thrown.expect(NullPointerException.class); + thrown.expectMessage("labelValues"); + derivedLongGauge.removeTimeSeries(null); + } +} |