/*
* Copyright 2012-2017 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.export;
import java.util.Collection;
import java.util.HashSet;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import org.springframework.boot.actuate.metrics.Metric;
import org.springframework.boot.actuate.metrics.reader.PrefixMetricReader;
import org.springframework.boot.actuate.metrics.repository.MultiMetricRepository;
import org.springframework.boot.actuate.metrics.writer.Delta;
import org.springframework.boot.actuate.metrics.writer.PrefixMetricWriter;
/**
* A convenient exporter for a group of metrics from a {@link PrefixMetricReader}. Exports
* all metrics whose name starts with a prefix (or all metrics if the prefix is empty).
*
* @author Dave Syer
* @since 1.3.0
*/
public class PrefixMetricGroupExporter extends AbstractMetricExporter {
private final PrefixMetricReader reader;
private final PrefixMetricWriter writer;
private ConcurrentMap<String, Long> counts = new ConcurrentHashMap<>();
private Set<String> groups = new HashSet<>();
/**
* Create a new exporter for metrics to a writer based on an empty prefix for the
* metric names.
* @param reader a reader as the source of metrics
* @param writer the writer to send the metrics to
*/
public PrefixMetricGroupExporter(PrefixMetricReader reader,
PrefixMetricWriter writer) {
this(reader, writer, "");
}
/**
* Create a new exporter for metrics to a writer based on a prefix for the metric
* names.
* @param reader a reader as the source of metrics
* @param writer the writer to send the metrics to
* @param prefix the prefix for metrics to export
*/
public PrefixMetricGroupExporter(PrefixMetricReader reader, PrefixMetricWriter writer,
String prefix) {
super(prefix);
this.reader = reader;
this.writer = writer;
}
/**
* The groups to export.
* @param groups the groups to set
*/
public void setGroups(Set<String> groups) {
this.groups = groups;
}
@Override
protected Iterable<String> groups() {
if ((this.reader instanceof MultiMetricRepository) && this.groups.isEmpty()) {
return ((MultiMetricRepository) this.reader).groups();
}
return this.groups;
}
@Override
protected Iterable<Metric<?>> next(String group) {
return this.reader.findAll(group);
}
@Override
protected void write(String group, Collection<Metric<?>> values) {
if (group.contains("counter.")) {
for (Metric<?> value : values) {
this.writer.increment(group, calculateDelta(value));
}
}
else {
this.writer.set(group, values);
}
}
private Delta<?> calculateDelta(Metric<?> value) {
long delta = value.getValue().longValue();
Long old = this.counts.replace(value.getName(), delta);
if (old != null) {
delta = delta - old;
}
else {
this.counts.putIfAbsent(value.getName(), delta);
}
return new Delta<>(value.getName(), delta, value.getTimestamp());
}
}