io.opencensus.metrics.data.Exemplar Maven / Gradle / Ivy
/*
* Copyright 2019, 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.data;
import static io.opencensus.internal.Utils.checkNotNull;
import com.google.auto.value.AutoValue;
import io.opencensus.common.Timestamp;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;
import javax.annotation.concurrent.Immutable;
/**
* An example point that may be used to annotate aggregated distribution values, associated with a
* histogram bucket.
*
* @since 0.20
*/
@Immutable
@AutoValue
public abstract class Exemplar {
Exemplar() {}
/**
* Returns value of the {@link Exemplar} point.
*
* @return value of the {@code Exemplar} point.
* @since 0.20
*/
public abstract double getValue();
/**
* Returns the time that this {@link Exemplar}'s value was recorded.
*
* @return the time that this {@code Exemplar}'s value was recorded.
* @since 0.20
*/
public abstract Timestamp getTimestamp();
/**
* Returns the contextual information about the example value.
*
* @return the contextual information about the example value.
* @since 0.20
*/
public abstract Map getAttachments();
/**
* Creates an {@link Exemplar}.
*
* @param value value of the {@link Exemplar} point.
* @param timestamp the time that this {@code Exemplar}'s value was recorded.
* @param attachments the contextual information about the example value.
* @return an {@code Exemplar}.
* @since 0.20
*/
public static Exemplar create(
double value, Timestamp timestamp, Map attachments) {
checkNotNull(attachments, "attachments");
Map attachmentsCopy =
Collections.unmodifiableMap(new HashMap(attachments));
for (Entry entry : attachmentsCopy.entrySet()) {
checkNotNull(entry.getKey(), "key of attachments");
checkNotNull(entry.getValue(), "value of attachments");
}
return new AutoValue_Exemplar(value, timestamp, attachmentsCopy);
}
}