org.apache.activemq.artemis.utils.SoftValueLongObjectHashMap Maven / Gradle / Ivy
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* 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.activemq.artemis.utils;
import java.lang.ref.ReferenceQueue;
import java.lang.ref.SoftReference;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Comparator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.TreeSet;
import io.netty.util.collection.LongObjectHashMap;
import io.netty.util.collection.LongObjectMap;
import org.apache.activemq.artemis.shaded.org.jboss.logging.Logger;
public class SoftValueLongObjectHashMap implements LongObjectMap {
private static final Logger logger = Logger.getLogger(SoftValueLongObjectHashMap.class);
// The soft references that are already good.
// too bad there's no way to override the queue method on ReferenceQueue, so I wouldn't need this
private final ReferenceQueue refQueue = new ReferenceQueue<>();
private final LongObjectMap> mapDelegate = new LongObjectHashMap<>();
private long usedCounter = 0;
private int maxElements;
public interface ValueCache {
boolean isLive();
}
public SoftValueLongObjectHashMap(final int maxElements) {
this.maxElements = maxElements;
}
public void setMaxElements(final int maxElements) {
this.maxElements = maxElements;
checkCacheSize();
}
public int getMaxEelements() {
return this.maxElements;
}
/**
* @see java.util.Map#size()
*/
@Override
public int size() {
processQueue();
return mapDelegate.size();
}
/**
* @see java.util.Map#isEmpty()
*/
@Override
public boolean isEmpty() {
processQueue();
return mapDelegate.isEmpty();
}
/**
* @param key
* @see java.util.Map#containsKey(java.lang.Object)
*/
@Override
public boolean containsKey(final Object key) {
return containsKey(objectToKey(key));
}
/**
* @param value
* @see java.util.Map#containsValue(java.lang.Object)
*/
@Override
public boolean containsValue(final Object value) {
processQueue();
for (AggregatedSoftReference valueIter : mapDelegate.values()) {
V valueElement = valueIter.get();
if (valueElement != null && value.equals(valueElement)) {
return true;
}
}
return false;
}
private static long objectToKey(Object key) {
return ((Long) key).longValue();
}
/**
* @param key
* @see java.util.Map#get(java.lang.Object)
*/
@Override
public V get(final Object key) {
return get(objectToKey(key));
}
@Override
public V put(Long key, V value) {
return put(objectToKey(key), value);
}
@Override
public V get(long key) {
processQueue();
AggregatedSoftReference value = mapDelegate.get(key);
if (value != null) {
usedCounter++;
value.used(usedCounter);
return value.get();
} else {
return null;
}
}
/**
* @param key
* @param value
* @see java.util.Map#put(java.lang.Object, java.lang.Object)
*/
@Override
public V put(final long key, final V value) {
processQueue();
AggregatedSoftReference newRef = createReference(key, value);
AggregatedSoftReference oldRef = mapDelegate.put(key, newRef);
checkCacheSize();
usedCounter++;
newRef.used(usedCounter);
if (oldRef != null) {
return oldRef.get();
} else {
return null;
}
}
@Override
public V remove(long key) {
processQueue();
AggregatedSoftReference ref = mapDelegate.remove(key);
if (ref != null) {
return ref.get();
} else {
return null;
}
}
private void checkCacheSize() {
if (maxElements > 0 && mapDelegate.size() > maxElements) {
TreeSet usedReferences = new TreeSet<>(new ComparatorAgregated());
for (AggregatedSoftReference ref : mapDelegate.values()) {
V v = ref.get();
if (v != null && !v.isLive()) {
usedReferences.add(ref);
}
}
for (AggregatedSoftReference ref : usedReferences) {
if (ref.used > 0) {
Object removed = mapDelegate.remove(ref.key);
if (logger.isTraceEnabled()) {
logger.trace("Removing " + removed + " with id = " + ref.key + " from SoftValueLongObjectHashMap");
}
if (mapDelegate.size() <= maxElements) {
break;
}
}
}
}
}
class ComparatorAgregated implements Comparator {
@Override
public int compare(AggregatedSoftReference o1, AggregatedSoftReference o2) {
long k = o1.used - o2.used;
if (k > 0) {
return 1;
} else if (k < 0) {
return -1;
}
k = o1.hashCode() - o2.hashCode();
if (k > 0) {
return 1;
} else if (k < 0) {
return -1;
} else {
return 0;
}
}
}
/**
* @param key
* @see java.util.Map#remove(java.lang.Object)
*/
@Override
public V remove(final Object key) {
return remove(objectToKey(key));
}
/**
* @param m
* @see java.util.Map#putAll(java.util.Map)
*/
@Override
public void putAll(final Map m) {
processQueue();
if (m instanceof LongObjectMap) {
final LongObjectMap primitiveMap = (LongObjectMap) m;
for (PrimitiveEntry entry : primitiveMap.entries()) {
put(entry.key(), entry.value());
}
} else {
for (Map.Entry e : m.entrySet()) {
put(e.getKey(), e.getValue());
}
}
}
/**
* @see java.util.Map#clear()
*/
@Override
public void clear() {
mapDelegate.clear();
}
/**
* @see java.util.Map#keySet()
*/
@Override
public Set keySet() {
processQueue();
return mapDelegate.keySet();
}
/**
* @see java.util.Map#values()
*/
@Override
public Collection values() {
processQueue();
ArrayList list = new ArrayList<>();
for (AggregatedSoftReference refs : mapDelegate.values()) {
V value = refs.get();
if (value != null) {
list.add(value);
}
}
return list;
}
@Override
public Set> entrySet() {
return null;
}
@Override
public Iterable> entries() {
processQueue();
final int size = mapDelegate.size();
final List> entries = new ArrayList<>(size);
for (PrimitiveEntry> pair : mapDelegate.entries()) {
V value = pair.value().get();
if (value != null) {
entries.add(new EntryElement<>(pair.key(), value));
}
}
return entries;
}
@Override
public boolean containsKey(long key) {
processQueue();
return mapDelegate.containsKey(key);
}
/**
* @param o
* @see java.util.Map#equals(java.lang.Object)
*/
@Override
public boolean equals(final Object o) {
processQueue();
return mapDelegate.equals(o);
}
/**
* @see java.util.Map#hashCode()
*/
@Override
public int hashCode() {
return mapDelegate.hashCode();
}
@SuppressWarnings("unchecked")
private void processQueue() {
AggregatedSoftReference ref;
while ((ref = (AggregatedSoftReference) this.refQueue.poll()) != null) {
logger.tracef("Removing reference through processQueue:: %s", ref.get());
mapDelegate.remove(ref.key);
}
}
private AggregatedSoftReference createReference(final long key, final V value) {
return new AggregatedSoftReference(key, value, refQueue);
}
static final class AggregatedSoftReference extends SoftReference {
final long key;
long used = 0;
public long getUsed() {
return used;
}
public void used(long value) {
this.used = value;
}
AggregatedSoftReference(final long key, final V referent, ReferenceQueue refQueue) {
super(referent, refQueue);
this.key = key;
}
@Override
public String toString() {
return "AggregatedSoftReference [key=" + key + ", used=" + used + "]";
}
}
static final class EntryElement implements LongObjectMap.PrimitiveEntry {
final long key;
final V value;
EntryElement(final long key, final V value) {
this.key = key;
this.value = value;
}
@Override
public long key() {
return key;
}
@Override
public V value() {
return value;
}
@Override
@Deprecated
public void setValue(V value) {
throw new UnsupportedOperationException();
}
}
}
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