/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.apache.nifi.controller.status.history;
/**
* Describes a particular metric that is derived from a Status History
*
* @param <T> type of metric
*/
public interface MetricDescriptor<T> {
public enum Formatter {
COUNT,
DURATION,
DATA_SIZE
};
/**
* Specifies how the values should be formatted
*
* @return formatter for values
*/
Formatter getFormatter();
/**
* @return a human-readable description of the field
*/
String getDescription();
/**
* @return a human-readable label for the field
*/
String getLabel();
/**
* @return the name of a field
*/
String getField();
/**
* @return a {@link ValueMapper} that can be used to extract a value for the
* status history
*/
ValueMapper<T> getValueFunction();
/**
* @return a {@link ValueReducer} that can reduce multiple StatusSnapshots
* into a single Long value
*/
ValueReducer<StatusSnapshot, Long> getValueReducer();
}