Add Codahale metrics to /metrics endpoint

All metrics in the MetricRegistry have been added unconditionally for now.

Fixes gh-1795

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/autoconfigure/MetricRepositoryAutoConfiguration.java

@@ -21,11 +21,13 @@ import java.util.concurrent.Executor;
 
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.beans.factory.annotation.Qualifier;
+import org.springframework.boot.actuate.endpoint.MetricReaderPublicMetrics;
 import org.springframework.boot.actuate.endpoint.PublicMetrics;
 import org.springframework.boot.actuate.endpoint.RichGaugeReaderPublicMetrics;
 import org.springframework.boot.actuate.metrics.CounterService;
 import org.springframework.boot.actuate.metrics.GaugeService;
 import org.springframework.boot.actuate.metrics.export.Exporter;
+import org.springframework.boot.actuate.metrics.reader.MetricRegistryMetricReader;
 import org.springframework.boot.actuate.metrics.repository.InMemoryMetricRepository;
 import org.springframework.boot.actuate.metrics.repository.MetricRepository;
 import org.springframework.boot.actuate.metrics.rich.RichGaugeReader;
@@ -184,6 +186,12 @@ public class MetricRepositoryAutoConfiguration {
 		public MetricWriter primaryMetricWriter(List<MetricWriter> writers) {
 			return new CompositeMetricWriter(writers);
 		}
+		
+		@Bean
+		public PublicMetrics codahalePublicMetrics(MetricRegistry metricRegistry) {
+			MetricRegistryMetricReader reader = new MetricRegistryMetricReader(metricRegistry);
+			return new MetricReaderPublicMetrics(reader);
+		}
 
 	}
 

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/metrics/reader/MetricRegistryMetricReader.java

+/*
+ * Copyright 2013-2104 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.reader;
+
+import java.beans.PropertyDescriptor;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.TimeUnit;
+
+import org.springframework.beans.BeanUtils;
+import org.springframework.beans.BeanWrapperImpl;
+import org.springframework.boot.actuate.metrics.Metric;
+import org.springframework.util.ClassUtils;
+import org.springframework.util.LinkedMultiValueMap;
+import org.springframework.util.MultiValueMap;
+import org.springframework.util.StringUtils;
+
+import com.codahale.metrics.Counter;
+import com.codahale.metrics.Gauge;
+import com.codahale.metrics.Histogram;
+import com.codahale.metrics.Meter;
+import com.codahale.metrics.MetricRegistry;
+import com.codahale.metrics.MetricRegistryListener;
+import com.codahale.metrics.Sampling;
+import com.codahale.metrics.Timer;
+
+/**
+ * A Spring Boot {@link MetricReader} that reads metrics from a Codahale
+ * {@link MetricRegistry}. Gauges and Counters are reflected as a single value. Timers,
+ * Meters and Histograms are expanded into sets of metrics containing all the properties
+ * of type Number.
+ * 
+ * @author Dave Syer
+ *
+ */
+public class MetricRegistryMetricReader implements MetricReader, MetricRegistryListener {
+
+	private static Map<Class<?>, Set<String>> numberKeys = new ConcurrentHashMap<Class<?>, Set<String>>();
+
+	private MetricRegistry registry;
+
+	private Map<String, String> names = new HashMap<String, String>();
+
+	private MultiValueMap<String, String> reverse = new LinkedMultiValueMap<String, String>();
+
+	public MetricRegistryMetricReader(MetricRegistry registry) {
+		this.registry = registry;
+		registry.addListener(this);
+	}
+
+	@Override
+	public Metric<?> findOne(String metricName) {
+		if (!names.containsKey(metricName)) {
+			return null;
+		}
+		com.codahale.metrics.Metric metric = registry.getMetrics().get(
+				names.get(metricName));
+		if (metric instanceof Counter) {
+			Counter counter = (Counter) metric;
+			return new Metric<Number>(metricName, counter.getCount());
+		}
+		if (metric instanceof Gauge) {
+			@SuppressWarnings("unchecked")
+			Gauge<Number> value = (Gauge<Number>) metric;
+			return new Metric<Number>(metricName, value.getValue());
+		}
+		if (metric instanceof Sampling) {
+			if (metricName.contains(".snapshot.")) {
+				Number value = getMetric(((Sampling) metric).getSnapshot(), metricName);
+				if (metric instanceof Timer) {
+					// convert back to MILLISEC
+					value = TimeUnit.MILLISECONDS.convert(value.longValue(),
+							TimeUnit.NANOSECONDS);
+				}
+				return new Metric<Number>(metricName, value);
+			}
+		}
+		return new Metric<Number>(metricName, getMetric(metric, metricName));
+	}
+
+	@Override
+	public Iterable<Metric<?>> findAll() {
+		return new Iterable<Metric<?>>() {
+			@Override
+			public Iterator<Metric<?>> iterator() {
+				return new MetricRegistryIterator();
+			}
+		};
+	}
+
+	@Override
+	public long count() {
+		return names.size();
+	}
+
+	@Override
+	public void onGaugeAdded(String name, Gauge<?> gauge) {
+		names.put(name, name);
+		reverse.add(name, name);
+	}
+
+	@Override
+	public void onGaugeRemoved(String name) {
+		remove(name);
+	}
+
+	public void onCounterAdded(String name, Counter counter) {
+		names.put(name, name);
+		reverse.add(name, name);
+	}
+
+	@Override
+	public void onCounterRemoved(String name) {
+		remove(name);
+	}
+
+	@Override
+	public void onHistogramAdded(String name, Histogram histogram) {
+		for (String key : getNumberKeys(histogram)) {
+			String metricName = name + "." + key;
+			names.put(metricName, name);
+			reverse.add(name, metricName);
+		}
+		for (String key : getNumberKeys(histogram.getSnapshot())) {
+			String metricName = name + ".snapshot." + key;
+			names.put(metricName, name);
+			reverse.add(name, metricName);
+		}
+	}
+
+	@Override
+	public void onHistogramRemoved(String name) {
+		remove(name);
+	}
+
+	@Override
+	public void onMeterAdded(String name, Meter meter) {
+		for (String key : getNumberKeys(meter)) {
+			String metricName = name + "." + key;
+			names.put(metricName, name);
+			reverse.add(name, metricName);
+		}
+	}
+
+	@Override
+	public void onMeterRemoved(String name) {
+		remove(name);
+	}
+
+	@Override
+	public void onTimerAdded(String name, Timer timer) {
+		for (String key : getNumberKeys(timer)) {
+			String metricName = name + "." + key;
+			names.put(metricName, name);
+			reverse.add(name, metricName);
+		}
+		for (String key : getNumberKeys(timer.getSnapshot())) {
+			String metricName = name + ".snapshot." + key;
+			names.put(metricName, name);
+			reverse.add(name, metricName);
+		}
+	}
+
+	@Override
+	public void onTimerRemoved(String name) {
+		remove(name);
+	}
+
+	private void remove(String name) {
+		for (String key : reverse.get(name)) {
+			names.remove(name + "." + key);
+		}
+		reverse.remove(name);
+	}
+
+	private class MetricRegistryIterator implements Iterator<Metric<?>> {
+
+		private Iterator<String> iterator;
+
+		public MetricRegistryIterator() {
+			this.iterator = new HashSet<String>(
+					MetricRegistryMetricReader.this.names.keySet()).iterator();
+		}
+
+		@Override
+		public boolean hasNext() {
+			return iterator.hasNext();
+		}
+
+		@Override
+		public Metric<?> next() {
+			String name = iterator.next();
+			return MetricRegistryMetricReader.this.findOne(name);
+		}
+
+	}
+
+	private static Set<String> getNumberKeys(Object metric) {
+		Set<String> result = numberKeys.containsKey(metric.getClass()) ? numberKeys
+				.get(metric.getClass()) : new HashSet<String>();
+		if (result.isEmpty()) {
+			for (PropertyDescriptor descriptor : BeanUtils.getPropertyDescriptors(metric
+					.getClass())) {
+				if (ClassUtils.isAssignable(Number.class, descriptor.getPropertyType())) {
+					result.add(descriptor.getName());
+				}
+			}
+			numberKeys.put(metric.getClass(), result);
+		}
+		return result;
+	}
+
+	private static Number getMetric(Object metric, String metricName) {
+		String key = StringUtils.getFilenameExtension(metricName);
+		return (Number) new BeanWrapperImpl(metric).getPropertyValue(key);
+	}
+
+}