package org.apache.solr.search;
/*
* 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.
*/
import org.apache.solr.common.SolrException;
import org.apache.solr.common.util.NamedList;
import org.apache.solr.common.util.SimpleOrderedMap;
import org.apache.solr.core.SolrCore;
import org.apache.solr.util.ConcurrentLFUCache;
import java.io.Serializable;
import java.net.URL;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.CopyOnWriteArrayList;
/**
* SolrCache based on ConcurrentLFUCache implementation.
* <p/>
* This implementation does not use a separate cleanup thread. Instead it uses the calling thread
* itself to do the cleanup when the size of the cache exceeds certain limits.
* <p/>
* Also see <a href="http://wiki.apache.org/solr/SolrCaching">SolrCaching</a>
* <p/>
* <b>This API is experimental and subject to change</b>
*
* @see org.apache.solr.util.ConcurrentLFUCache
* @see org.apache.solr.search.SolrCache
* @since solr 3.6
*/
public class LFUCache<K, V> implements SolrCache<K, V> {
// contains the statistics objects for all open caches of the same type
private List<ConcurrentLFUCache.Stats> statsList;
private long warmupTime = 0;
private String name;
private int autowarmCount;
private State state;
private CacheRegenerator regenerator;
private String description = "Concurrent LFU Cache";
private ConcurrentLFUCache<K, V> cache;
private int showItems = 0;
private Boolean timeDecay = true;
@Override
public Object init(Map args, Object persistence, CacheRegenerator regenerator) {
state = State.CREATED;
this.regenerator = regenerator;
name = (String) args.get("name");
String str = (String) args.get("size");
int limit = str == null ? 1024 : Integer.parseInt(str);
int minLimit;
str = (String) args.get("minSize");
if (str == null) {
minLimit = (int) (limit * 0.9);
} else {
minLimit = Integer.parseInt(str);
}
if (minLimit == 0) minLimit = 1;
if (limit <= minLimit) limit = minLimit + 1;
int acceptableSize;
str = (String) args.get("acceptableSize");
if (str == null) {
acceptableSize = (int) (limit * 0.95);
} else {
acceptableSize = Integer.parseInt(str);
}
// acceptable limit should be somewhere between minLimit and limit
acceptableSize = Math.max(minLimit, acceptableSize);
str = (String) args.get("initialSize");
final int initialSize = str == null ? limit : Integer.parseInt(str);
str = (String) args.get("autowarmCount");
autowarmCount = str == null ? 0 : Integer.parseInt(str);
str = (String) args.get("cleanupThread");
boolean newThread = str == null ? false : Boolean.parseBoolean(str);
str = (String) args.get("showItems");
showItems = str == null ? 0 : Integer.parseInt(str);
// Don't make this "efficient" by removing the test, default is true and omitting the param will make it false.
str = (String) args.get("timeDecay");
timeDecay = (str == null) ? true : Boolean.parseBoolean(str);
description = "Concurrent LFU Cache(maxSize=" + limit + ", initialSize=" + initialSize +
", minSize=" + minLimit + ", acceptableSize=" + acceptableSize + ", cleanupThread=" + newThread +
", timeDecay=" + Boolean.toString(timeDecay);
if (autowarmCount > 0) {
description += ", autowarmCount=" + autowarmCount + ", regenerator=" + regenerator;
}
description += ')';
cache = new ConcurrentLFUCache<K, V>(limit, minLimit, acceptableSize, initialSize, newThread, false, null, timeDecay);
cache.setAlive(false);
statsList = (List<ConcurrentLFUCache.Stats>) persistence;
if (statsList == null) {
// must be the first time a cache of this type is being created
// Use a CopyOnWriteArrayList since puts are very rare and iteration may be a frequent operation
// because it is used in getStatistics()
statsList = new CopyOnWriteArrayList<ConcurrentLFUCache.Stats>();
// the first entry will be for cumulative stats of caches that have been closed.
statsList.add(new ConcurrentLFUCache.Stats());
}
statsList.add(cache.getStats());
return statsList;
}
@Override
public String name() {
return name;
}
@Override
public int size() {
return cache.size();
}
@Override
public void put(K key, V value) {
cache.put(key, value);
}
@Override
public V get(K key) {
return cache.get(key);
}
@Override
public V check(K key) {
return get(key);
}
@Override
public void clear() {
cache.clear();
}
@Override
public void setState(State state) {
this.state = state;
cache.setAlive(state == State.LIVE);
}
@Override
public State getState() {
return state;
}
@Override
public void warm(SolrIndexSearcher.WarmContext warmContext) {
if (regenerator == null) return;
warmContext.cache = this;
long warmingStartTime = System.currentTimeMillis();
LFUCache other = (LFUCache) warmContext.oldCache;
// warm entries
if (autowarmCount != 0) {
int sz = other.size();
if (autowarmCount != -1) sz = Math.min(sz, autowarmCount);
Map items = other.cache.getMostUsedItems(sz);
Map.Entry[] itemsArr = new Map.Entry[items.size()];
int counter = 0;
for (Object mapEntry : items.entrySet()) {
itemsArr[counter++] = (Map.Entry) mapEntry;
}
for (int i = itemsArr.length - 1; i >= 0; i--) {
try {
boolean continueRegen = regenerator.regenerateItem(warmContext, itemsArr[i].getKey(), itemsArr[i].getValue());
if (!continueRegen) break;
} catch (Exception e) {
SolrException.log(log, "Error during auto-warming of key:" + itemsArr[i].getKey(), e);
}
}
}
warmupTime = System.currentTimeMillis() - warmingStartTime;
}
@Override
public void close() {
// add the stats to the cumulative stats object (the first in the statsList)
statsList.get(0).add(cache.getStats());
statsList.remove(cache.getStats());
cache.destroy();
}
//////////////////////// SolrInfoMBeans methods //////////////////////
@Override
public String getName() {
return LFUCache.class.getName();
}
@Override
public String getVersion() {
return SolrCore.version;
}
@Override
public String getDescription() {
return description;
}
@Override
public Category getCategory() {
return Category.CACHE;
}
@Override
public String getSource() {
return "$URL$";
}
@Override
public URL[] getDocs() {
return null;
}
// returns a ratio, not a percent.
private static String calcHitRatio(long lookups, long hits) {
if (lookups == 0) return "0.00";
if (lookups == hits) return "1.00";
int hundredths = (int) (hits * 100 / lookups); // rounded down
if (hundredths < 10) return "0.0" + hundredths;
return "0." + hundredths;
}
@Override
public NamedList getStatistics() {
NamedList<Serializable> lst = new SimpleOrderedMap<Serializable>();
if (cache == null) return lst;
ConcurrentLFUCache.Stats stats = cache.getStats();
long lookups = stats.getCumulativeLookups();
long hits = stats.getCumulativeHits();
long inserts = stats.getCumulativePuts();
long evictions = stats.getCumulativeEvictions();
long size = stats.getCurrentSize();
lst.add("lookups", lookups);
lst.add("hits", hits);
lst.add("hitratio", calcHitRatio(lookups, hits));
lst.add("inserts", inserts);
lst.add("evictions", evictions);
lst.add("size", size);
lst.add("warmupTime", warmupTime);
lst.add("timeDecay", timeDecay);
long clookups = 0;
long chits = 0;
long cinserts = 0;
long cevictions = 0;
// NOTE: It is safe to iterate on a CopyOnWriteArrayList
for (ConcurrentLFUCache.Stats statistiscs : statsList) {
clookups += statistiscs.getCumulativeLookups();
chits += statistiscs.getCumulativeHits();
cinserts += statistiscs.getCumulativePuts();
cevictions += statistiscs.getCumulativeEvictions();
}
lst.add("cumulative_lookups", clookups);
lst.add("cumulative_hits", chits);
lst.add("cumulative_hitratio", calcHitRatio(clookups, chits));
lst.add("cumulative_inserts", cinserts);
lst.add("cumulative_evictions", cevictions);
if (showItems != 0) {
Map items = cache.getMostUsedItems(showItems == -1 ? Integer.MAX_VALUE : showItems);
for (Map.Entry e : (Set<Map.Entry>) items.entrySet()) {
Object k = e.getKey();
Object v = e.getValue();
String ks = "item_" + k;
String vs = v.toString();
lst.add(ks, vs);
}
}
return lst;
}
@Override
public String toString() {
return name + getStatistics().toString();
}
}