org.eclipse.microprofile.metrics.MetricID Maven / Gradle / Ivy
/*
**********************************************************************
* Copyright (c) 2018, 2019 Contributors to the Eclipse Foundation
* 2018, 2019 IBM Corporation and others
* and other contributors as indicated by the @author tags.
*
* See the NOTICES file(s) distributed with this work for additional
* information regarding copyright ownership.
*
* 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.
*
* SPDX-License-Identifier: Apache-2.0
**********************************************************************/
package org.eclipse.microprofile.metrics;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Objects;
import java.util.TreeMap;
import java.util.stream.Collectors;
import java.util.stream.Stream;
/**
*
* A unique identifier for {@link Metric} and {@link Metadata} that are registered in the {@link MetricRegistry}
*
* The MetricID contains:
*
* - {@code Name}: (Required) The name of the metric.
* - {@code Tags}: (Optional) The tags (represented by {@link Tag} objects) of the metric. The tag name must match the
* regex `[a-zA-Z_][a-zA-Z0-9_]*` (Ascii alphabet, numbers and underscore). The tag value may contain any UTF-8 encoded
* character.
*
*/
public class MetricID implements Comparable {
/**
* Name of the metric.
*
* A required field which holds the name of the metric object.
*
*/
private final String name;
/**
* Tags of the metric.
*/
private final Map tags = new TreeMap();
/**
* Constructs a MetricID with the given metric name and no tags. If global tags are available then they will be
* appended to this MetricID.
*
* @param name
* the name of the metric
*/
public MetricID(String name) {
this(name, null);
}
/**
* Constructs a MetricID with the given metric name and {@link Tag}s. If global tags are available then they will be
* appended to this MetricID
*
* @param name
* the name of the metric
* @param tags
* the tags associated with this metric
*/
public MetricID(String name, Tag... tags) {
this.name = name;
addTags(tags);
}
/**
* Returns the Metric name associated with this MetricID
*
* @return the Metric name associated with this MetricID
*/
public String getName() {
return name;
}
/**
* Returns the underlying map containing the tags.
*
* @return a {@link Map} of tags
*/
public Map getTags() {
return Collections.unmodifiableMap(tags);
}
/**
* Gets the list of tags as a single String in the format 'key="value",key2="value2",...'
*
* @return a String containing the tags
*/
public String getTagsAsString() {
return this.tags.entrySet().stream().map(e -> e.getKey() + "=\"" + e.getValue() + "\"")
.collect(Collectors.joining(","));
}
/**
* Gets the list of tags as a list of {@link Tag} objects
*
* @return a a list of Tag objects
*/
public List getTagsAsList() {
List list = new ArrayList<>();
this.tags.forEach((key, value) -> list.add(new Tag(key, value)));
return Collections.unmodifiableList(list);
}
/**
* Gets the list of tags as an array of {@link Tag} objects.
*
* @return An array of tags
*/
public Tag[] getTagsAsArray() {
Tag[] result = new Tag[tags.size()];
int i = 0;
for (Entry entry : tags.entrySet()) {
result[i] = new Tag(entry.getKey(), entry.getValue());
i++;
}
return result;
}
/** {@inheritDoc} */
@Override
public boolean equals(Object o) {
if (this == o) {
return true;
}
if (!(o instanceof MetricID)) {
return false;
}
MetricID that = (MetricID) o;
return Objects.equals(this.name, that.getName()) && Objects.equals(this.tags, that.getTags());
}
/** {@inheritDoc} */
@Override
public int hashCode() {
return Objects.hash(name, tags);
}
@Override
public String toString() {
return "MetricID{" +
"name='" + name + '\'' +
", tags=[" + getTagsAsString() +
"]}";
}
/**
* Add multiple {@link Tag} objects This method will call {@link #addTag(Tag)} on each tag. If a key already exists
* then it will be overwritten.
*
* @param tagArray
* an array of {@link Tag} objects
*/
private void addTags(Tag[] tagArray) {
if (tagArray == null || tagArray.length == 0) {
return;
}
Stream.of(tagArray).forEach(this::addTag);
}
/**
* Adds a singular {@link Tag} object into the MetricID. If the tag key/name already exists then it will be
* overwritten with the new value.
*
* @param tag
* the {@link Tag} object
*/
private void addTag(Tag tag) {
if (tag == null || tag.getTagName() == null || tag.getTagValue() == null) {
return;
}
tags.put(tag.getTagName(), tag.getTagValue());
}
/**
* Compares two MetricID objects through the following steps:
*
* - Compares the names of the two MetricIDs lexicographically.
* - If the names are equal: Compare the number of tags.
* - If the tag lengths are equal: Compare the Tags (sorted by the Tag's key value)
*
* - a) Compare the Tag names/keys lexicographically
* - b) If keys are equal, compare the Tag values lexicographically
*
*
*
*
* @param other
* the other MetricID
*/
@Override
public int compareTo(MetricID other) {
int compareVal = this.name.compareTo(other.getName());
if (compareVal == 0) {
compareVal = this.tags.size() - other.getTags().size();
if (compareVal == 0) {
Iterator> thisIterator = tags.entrySet().iterator();
Iterator> otherIterator = other.getTags().entrySet().iterator();
while (thisIterator.hasNext() && otherIterator.hasNext()) {
Entry thisEntry = thisIterator.next();
Entry otherEntry = otherIterator.next();
compareVal = thisEntry.getKey().compareTo(otherEntry.getKey());
if (compareVal != 0) {
return compareVal;
} else {
compareVal = thisEntry.getValue().compareTo(otherEntry.getValue());
if (compareVal != 0) {
return compareVal;
}
}
}
}
}
return compareVal;
}
}