com.google.monitoring.metrics.LabelDescriptor Maven / Gradle / Ivy
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// Copyright 2017 Google LLC. All Rights Reserved.
//
// 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 com.google.monitoring.metrics;
import static com.google.common.base.Preconditions.checkArgument;
import com.google.auto.value.AutoValue;
import com.google.re2j.Pattern;
/**
* Definition of a metric label.
*
* If a metric is created with labels, corresponding label values must be provided when setting
* values on the metric.
*/
@AutoValue
public abstract class LabelDescriptor {
private static final Pattern ALLOWED_LABEL_PATTERN = Pattern.compile("\\w+");
LabelDescriptor() {}
/**
* Returns a new {@link LabelDescriptor}.
*
* @param name identifier for label
* @param description human-readable description of label
* @throws IllegalArgumentException if {@code name} isn't {@code \w+} or {@code description} is
* blank
*/
public static LabelDescriptor create(String name, String description) {
checkArgument(!name.isEmpty(), "Name must not be empty");
checkArgument(!description.isEmpty(), "Description must not be empty");
checkArgument(
ALLOWED_LABEL_PATTERN.matches(name),
"Label name must match the regex %s",
ALLOWED_LABEL_PATTERN);
return new AutoValue_LabelDescriptor(name, description);
}
public abstract String name();
public abstract String description();
}