PrefixMetricWriter.java

/*
 * Copyright 2012-2015 the original author or 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 org.springframework.boot.actuate.metrics.writer;

import java.util.Collection;

import org.springframework.boot.actuate.metrics.Metric;

/**
 * A writer for metrics that allows efficient storage of groups of metrics with a common
 * name prefix (their group name).
 *
 * @author Dave Syer
 * @since 1.1.0
 */
public interface PrefixMetricWriter {

	/**
	 * Save some metric values and associate them with a group name.
	 * @param group the name of the group
	 * @param values the metric values to save
	 */
	void set(String group, Collection<Metric<?>> values);

	/**
	 * Increment the value of a metric (or decrement if the delta is negative). The name
	 * of the metric to increment is {@code group + "." + delta.name}.
	 * @param group the name of the group
	 * @param delta the amount to increment by
	 */
	void increment(String group, Delta<?> delta);

	/**
	 * Rest the values of all metrics in the group. Implementations may choose to discard
	 * the old values.
	 * @param group reset the whole group
	 */
	void reset(String group);

}