/*
* 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.hadoop.metrics2.util;
import java.util.Collection;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Set;
import org.apache.hadoop.metrics2.Metric;
import org.apache.hadoop.metrics2.MetricsRecord;
import org.apache.hadoop.metrics2.MetricsTag;
/**
* A metrics cache for sinks that don't support sparse updates.
*/
public class MetricsCache {
private static final long serialVersionUID = 1L;
private final Map<String, RecMap> map = new HashMap<String, RecMap>();
static class RecMap extends HashMap<Collection<MetricsTag>, Record> {
private static final long serialVersionUID = 1L;
}
/**
* Cached record
*/
public static class Record {
final Map<String, String> tags = new LinkedHashMap<String, String>();
final Map<String, Metric> metrics = new LinkedHashMap<String, Metric>();
/**
* Get the tag value
* @param key name of the tag
* @return the tag value
*/
public String getTag(String key) {
return tags.get(key);
}
/**
* Get the metric value
* @param key name of the metric
* @return the metric value
*/
public Number getMetric(String key) {
Metric metric = metrics.get(key);
return metric != null ? metric.value() : null;
}
/**
* Get the metric value
* @param key name of the metric
* @return the metric value
*/
public Metric getMetricInstance(String key) {
return metrics.get(key);
}
/**
* @return entry set of metrics
*/
public Set<Map.Entry<String, Number>> metrics() {
Map<String, Number> map =
new LinkedHashMap<String,Number>(metrics.size());
for (Map.Entry<String, Metric> mapEntry : metrics.entrySet()) {
map.put(mapEntry.getKey(), mapEntry.getValue().value());
}
return map.entrySet();
}
/**
* @return entry set of metrics
*/
public Set<Map.Entry<String, Metric>> metricsEntrySet() {
return metrics.entrySet();
}
}
/**
* Update the cache and return the cached record
* @param mr the update record
* @param includingTags cache tag values (for later lookup by name) if true
* @return the updated cached record
*/
public Record update(MetricsRecord mr, boolean includingTags) {
String name = mr.name();
RecMap recMap = map.get(name);
if (recMap == null) {
recMap = new RecMap();
map.put(name, recMap);
}
Collection<MetricsTag> tags = (Collection<MetricsTag>)mr.tags();
Record rec = recMap.get(tags);
if (rec == null) {
rec = new Record();
recMap.put(tags, rec);
}
for (Metric m : mr.metrics()) {
rec.metrics.put(m.name(), m);
}
if (includingTags) {
// mostly for some sinks that include tags as part of a dense schema
for (MetricsTag t : mr.tags()) {
rec.tags.put(t.name(), t.value());
}
}
return rec;
}
public Record update(MetricsRecord mr) {
return update(mr, false);
}
/**
* Get the cached record
* @param name of the record
* @param tags of the record
* @return the cached record or null
*/
public Record get(String name, Collection<MetricsTag> tags) {
RecMap tmap = map.get(name);
if (tmap == null) return null;
return tmap.get(tags);
}
}