| /* |
| * 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.solr.util; |
| |
| import java.lang.invoke.MethodHandles; |
| import java.lang.ref.WeakReference; |
| import java.util.Iterator; |
| import java.util.LinkedHashMap; |
| import java.util.Map; |
| import java.util.TreeSet; |
| import java.util.concurrent.ConcurrentHashMap; |
| import java.util.concurrent.TimeUnit; |
| //import java.util.concurrent.atomic.AtomicInteger; |
| import java.util.concurrent.atomic.AtomicBoolean; |
| import java.util.concurrent.atomic.AtomicLong; |
| import java.util.concurrent.atomic.LongAdder; |
| import java.util.concurrent.locks.ReentrantLock; |
| import java.util.function.Function; |
| |
| import org.apache.lucene.util.Accountable; |
| import org.apache.lucene.util.RamUsageEstimator; |
| import org.apache.solr.common.util.Cache; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| import org.apache.solr.common.util.TimeSource; |
| |
| import static org.apache.lucene.util.RamUsageEstimator.HASHTABLE_RAM_BYTES_PER_ENTRY; |
| import static org.apache.lucene.util.RamUsageEstimator.QUERY_DEFAULT_RAM_BYTES_USED; |
| |
| /** |
| * A LFU cache implementation based upon ConcurrentHashMap. |
| * <p> |
| * This is not a terribly efficient implementation. The tricks used in the |
| * LRU version were not directly usable, perhaps it might be possible to |
| * rewrite them with LFU in mind. |
| * <p> |
| * <b>This API is experimental and subject to change</b> |
| * |
| * @since solr 1.6 |
| */ |
| public class ConcurrentLFUCache<K, V> implements Cache<K,V>, Accountable { |
| private static final Logger log = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass()); |
| private static final long BASE_RAM_BYTES_USED = |
| RamUsageEstimator.shallowSizeOfInstance(ConcurrentLFUCache.class) + |
| new Stats().ramBytesUsed() + |
| RamUsageEstimator.shallowSizeOfInstance(ConcurrentHashMap.class); |
| |
| private final ConcurrentHashMap<Object, CacheEntry<K, V>> map; |
| private int upperWaterMark, lowerWaterMark; |
| private final ReentrantLock markAndSweepLock = new ReentrantLock(true); |
| private boolean isCleaning = false; // not volatile... piggybacked on other volatile vars |
| private boolean newThreadForCleanup; |
| private boolean runCleanupThread; |
| private volatile boolean islive = true; |
| private final Stats stats = new Stats(); |
| @SuppressWarnings("unused") |
| private int acceptableWaterMark; |
| private long lowHitCount = 0; // not volatile, only accessed in the cleaning method |
| private final EvictionListener<K, V> evictionListener; |
| private CleanupThread cleanupThread; |
| private boolean timeDecay; |
| private long maxIdleTimeNs; |
| private final TimeSource timeSource = TimeSource.NANO_TIME; |
| private final AtomicLong oldestEntry = new AtomicLong(0L); |
| private final LongAdder ramBytes = new LongAdder(); |
| |
| public ConcurrentLFUCache(int upperWaterMark, final int lowerWaterMark, int acceptableSize, |
| int initialSize, boolean runCleanupThread, boolean runNewThreadForCleanup, |
| EvictionListener<K, V> evictionListener, boolean timeDecay) { |
| this(upperWaterMark, lowerWaterMark, acceptableSize, initialSize, runCleanupThread, |
| runNewThreadForCleanup, evictionListener, timeDecay, -1); |
| } |
| |
| public ConcurrentLFUCache(int upperWaterMark, final int lowerWaterMark, int acceptableSize, |
| int initialSize, boolean runCleanupThread, boolean runNewThreadForCleanup, |
| EvictionListener<K, V> evictionListener, boolean timeDecay, int maxIdleTimeSec) { |
| setUpperWaterMark(upperWaterMark); |
| setLowerWaterMark(lowerWaterMark); |
| setAcceptableWaterMark(acceptableSize); |
| map = new ConcurrentHashMap<>(initialSize); |
| this.evictionListener = evictionListener; |
| setNewThreadForCleanup(runNewThreadForCleanup); |
| setTimeDecay(timeDecay); |
| setMaxIdleTime(maxIdleTimeSec); |
| setRunCleanupThread(runCleanupThread); |
| } |
| |
| public ConcurrentLFUCache(int size, int lowerWatermark) { |
| this(size, lowerWatermark, (int) Math.floor((lowerWatermark + size) / 2), |
| (int) Math.ceil(0.75 * size), false, false, null, true, -1); |
| } |
| |
| public void setAlive(boolean live) { |
| islive = live; |
| } |
| |
| public void setUpperWaterMark(int upperWaterMark) { |
| if (upperWaterMark < 1) throw new IllegalArgumentException("upperWaterMark must be > 0"); |
| this.upperWaterMark = upperWaterMark; |
| } |
| |
| public void setLowerWaterMark(int lowerWaterMark) { |
| if (lowerWaterMark >= upperWaterMark) |
| throw new IllegalArgumentException("lowerWaterMark must be < upperWaterMark"); |
| this.lowerWaterMark = lowerWaterMark; |
| } |
| |
| public void setAcceptableWaterMark(int acceptableWaterMark) { |
| this.acceptableWaterMark = acceptableWaterMark; |
| } |
| |
| public void setTimeDecay(boolean timeDecay) { |
| this.timeDecay = timeDecay; |
| } |
| |
| public void setMaxIdleTime(int maxIdleTime) { |
| long oldMaxIdleTimeNs = maxIdleTimeNs; |
| maxIdleTimeNs = maxIdleTime > 0 ? TimeUnit.NANOSECONDS.convert(maxIdleTime, TimeUnit.SECONDS) : Long.MAX_VALUE; |
| if (cleanupThread != null && maxIdleTimeNs < oldMaxIdleTimeNs) { |
| cleanupThread.wakeThread(); |
| } |
| } |
| |
| public synchronized void setNewThreadForCleanup(boolean newThreadForCleanup) { |
| this.newThreadForCleanup = newThreadForCleanup; |
| if (newThreadForCleanup) { |
| setRunCleanupThread(false); |
| } |
| } |
| |
| public synchronized void setRunCleanupThread(boolean runCleanupThread) { |
| this.runCleanupThread = runCleanupThread; |
| if (this.runCleanupThread) { |
| newThreadForCleanup = false; |
| if (cleanupThread == null) { |
| cleanupThread = new CleanupThread(this); |
| cleanupThread.start(); |
| } |
| } else { |
| if (cleanupThread != null) { |
| cleanupThread.stopThread(); |
| cleanupThread = null; |
| } |
| } |
| } |
| |
| @Override |
| public V get(K key) { |
| CacheEntry<K, V> e = map.get(key); |
| if (e == null) { |
| if (islive) stats.missCounter.increment(); |
| } else if (islive) { |
| e.lastAccessed = timeSource.getEpochTimeNs(); |
| stats.accessCounter.increment(); |
| e.hits.increment(); |
| } |
| return e != null ? e.value : null; |
| } |
| |
| @Override |
| public V computeIfAbsent(K key, Function<? super K, ? extends V> mappingFunction) { |
| // prescreen access first |
| V val = get(key); |
| if (val != null) { |
| return val; |
| } |
| AtomicBoolean newValue = new AtomicBoolean(); |
| if (islive) { |
| stats.accessCounter.increment(); |
| } |
| CacheEntry<K, V> entry = map.computeIfAbsent(key, k -> { |
| V value = mappingFunction.apply(key); |
| // preserve the semantics of computeIfAbsent |
| if (value == null) { |
| return null; |
| } |
| CacheEntry<K, V> e = new CacheEntry<>(key, value, timeSource.getEpochTimeNs()); |
| newValue.set(true); |
| oldestEntry.updateAndGet(x -> x > e.lastAccessed || x == 0 ? e.lastAccessed : x); |
| stats.size.increment(); |
| ramBytes.add(e.ramBytesUsed() + HASHTABLE_RAM_BYTES_PER_ENTRY); // added key + value + entry |
| if (islive) { |
| stats.putCounter.increment(); |
| } else { |
| stats.nonLivePutCounter.increment(); |
| } |
| return e; |
| }); |
| if (newValue.get()) { |
| maybeMarkAndSweep(); |
| } else { |
| if (islive && entry != null) { |
| entry.lastAccessed = timeSource.getEpochTimeNs(); |
| entry.hits.increment(); |
| } |
| } |
| return entry != null ? entry.value : null; |
| } |
| |
| @Override |
| public V remove(K key) { |
| CacheEntry<K, V> cacheEntry = map.remove(key); |
| if (cacheEntry != null) { |
| stats.size.decrement(); |
| ramBytes.add(-cacheEntry.ramBytesUsed() - HASHTABLE_RAM_BYTES_PER_ENTRY); |
| return cacheEntry.value; |
| } |
| return null; |
| } |
| |
| @Override |
| public V put(K key, V val) { |
| if (val == null) return null; |
| CacheEntry<K, V> e = new CacheEntry<>(key, val, timeSource.getEpochTimeNs()); |
| return putCacheEntry(e); |
| } |
| |
| |
| |
| /** |
| * Visible for testing to create synthetic cache entries. |
| * @lucene.internal |
| */ |
| public V putCacheEntry(CacheEntry<K, V> e) { |
| stats.accessCounter.increment(); |
| // initialize oldestEntry |
| oldestEntry.updateAndGet(x -> x > e.lastAccessed || x == 0 ? e.lastAccessed : x); |
| CacheEntry<K, V> oldCacheEntry = map.put(e.key, e); |
| if (oldCacheEntry == null) { |
| stats.size.increment(); |
| ramBytes.add(e.ramBytesUsed() + HASHTABLE_RAM_BYTES_PER_ENTRY); // added key + value + entry |
| } else { |
| ramBytes.add(-oldCacheEntry.ramBytesUsed()); |
| ramBytes.add(e.ramBytesUsed()); |
| } |
| if (islive) { |
| stats.putCounter.increment(); |
| } else { |
| stats.nonLivePutCounter.increment(); |
| } |
| maybeMarkAndSweep(); |
| return oldCacheEntry == null ? null : oldCacheEntry.value; |
| } |
| |
| private void maybeMarkAndSweep() { |
| // Check if we need to clear out old entries from the cache. |
| // isCleaning variable is checked instead of markAndSweepLock.isLocked() |
| // for performance because every put invokation will check until |
| // the size is back to an acceptable level. |
| // |
| // There is a race between the check and the call to markAndSweep, but |
| // it's unimportant because markAndSweep actually aquires the lock or returns if it can't. |
| // |
| // Thread safety note: isCleaning read is piggybacked (comes after) other volatile reads |
| // in this method. |
| boolean evictByIdleTime = maxIdleTimeNs != Long.MAX_VALUE; |
| int currentSize = stats.size.intValue(); |
| long idleCutoff = evictByIdleTime ? timeSource.getEpochTimeNs() - maxIdleTimeNs : -1L; |
| if ((currentSize > upperWaterMark || (evictByIdleTime && oldestEntry.get() < idleCutoff)) && !isCleaning) { |
| if (newThreadForCleanup) { |
| new Thread(this::markAndSweep).start(); |
| } else if (cleanupThread != null) { |
| cleanupThread.wakeThread(); |
| } else { |
| markAndSweep(); |
| } |
| } |
| } |
| |
| /** |
| * Removes items from the cache to bring the size down to the lowerWaterMark. |
| * <p>Visible for unit testing.</p> |
| * @lucene.internal |
| */ |
| public void markAndSweep() { |
| if (!markAndSweepLock.tryLock()) return; |
| try { |
| long lowHitCount = this.lowHitCount; |
| isCleaning = true; |
| this.lowHitCount = lowHitCount; // volatile write to make isCleaning visible |
| |
| int sz = stats.size.intValue(); |
| boolean evictByIdleTime = maxIdleTimeNs != Long.MAX_VALUE; |
| long idleCutoff = evictByIdleTime ? timeSource.getEpochTimeNs() - maxIdleTimeNs : -1L; |
| if (sz <= upperWaterMark && (evictByIdleTime && oldestEntry.get() > idleCutoff)) { |
| /* SOLR-7585: Even though we acquired a lock, multiple threads might detect a need for calling this method. |
| * Locking keeps these from executing at the same time, so they run sequentially. The second and subsequent |
| * sequential runs of this method don't need to be done, since there are no elements to remove. |
| */ |
| return; |
| } |
| |
| // first evict by idleTime - it's less costly to do an additional pass over the |
| // map than to manage the outdated entries in a TreeSet |
| if (evictByIdleTime) { |
| long currentOldestEntry = Long.MAX_VALUE; |
| Iterator<Map.Entry<Object, CacheEntry<K, V>>> iterator = map.entrySet().iterator(); |
| while (iterator.hasNext()) { |
| Map.Entry<Object, CacheEntry<K, V>> entry = iterator.next(); |
| entry.getValue().lastAccessedCopy = entry.getValue().lastAccessed; |
| if (entry.getValue().lastAccessedCopy < idleCutoff) { |
| iterator.remove(); |
| postRemoveEntry(entry.getValue()); |
| stats.evictionIdleCounter.increment(); |
| } else { |
| if (entry.getValue().lastAccessedCopy < currentOldestEntry) { |
| currentOldestEntry = entry.getValue().lastAccessedCopy; |
| } |
| } |
| } |
| if (currentOldestEntry != Long.MAX_VALUE) { |
| oldestEntry.set(currentOldestEntry); |
| } |
| // refresh size and maybe return |
| sz = stats.size.intValue(); |
| if (sz <= upperWaterMark) { |
| return; |
| } |
| } |
| int wantToRemove = sz - lowerWaterMark; |
| |
| TreeSet<CacheEntry<K, V>> tree = new TreeSet<>(); |
| |
| for (CacheEntry<K, V> ce : map.values()) { |
| // set hitsCopy to avoid later Atomic reads. Primitive types are faster than the atomic get(). |
| ce.hitsCopy = ce.hits.longValue(); |
| ce.lastAccessedCopy = ce.lastAccessed; |
| if (timeDecay) { |
| ce.hits.reset(); |
| ce.hits.add(ce.hitsCopy >>> 1); |
| } |
| if (tree.size() < wantToRemove) { |
| tree.add(ce); |
| } else { |
| /* |
| * SOLR-7585: Before doing this part, make sure the TreeSet actually has an element, since the first() method |
| * fails with NoSuchElementException if the set is empty. If that test passes, check hits. This test may |
| * never actually fail due to the upperWaterMark check above, but we'll do it anyway. |
| */ |
| if (tree.size() > 0) { |
| /* If hits are not equal, we can remove before adding which is slightly faster. I can no longer remember |
| * why removing first is faster, but I vaguely remember being sure about it! |
| */ |
| if (ce.hitsCopy < tree.first().hitsCopy) { |
| tree.remove(tree.first()); |
| tree.add(ce); |
| } else if (ce.hitsCopy == tree.first().hitsCopy) { |
| tree.add(ce); |
| tree.remove(tree.first()); |
| } |
| } |
| } |
| } |
| |
| for (CacheEntry<K, V> e : tree) { |
| evictEntry(e.key); |
| } |
| if (evictByIdleTime) { |
| // do a full pass because we don't what is the max. age of remaining items |
| long currentOldestEntry = Long.MAX_VALUE; |
| for (CacheEntry<K, V> e : map.values()) { |
| if (e.lastAccessedCopy < currentOldestEntry) { |
| currentOldestEntry = e.lastAccessedCopy; |
| } |
| } |
| if (currentOldestEntry != Long.MAX_VALUE) { |
| oldestEntry.set(currentOldestEntry); |
| } |
| } |
| } finally { |
| isCleaning = false; // set before markAndSweep.unlock() for visibility |
| markAndSweepLock.unlock(); |
| } |
| } |
| |
| private void evictEntry(K key) { |
| CacheEntry<K, V> o = map.remove(key); |
| postRemoveEntry(o); |
| } |
| |
| private void postRemoveEntry(CacheEntry<K, V> o) { |
| if (o == null) return; |
| ramBytes.add(-(o.ramBytesUsed() + HASHTABLE_RAM_BYTES_PER_ENTRY)); |
| stats.size.decrement(); |
| stats.evictionCounter.increment(); |
| if (evictionListener != null) evictionListener.evictedEntry(o.key, o.value); |
| } |
| |
| /** |
| * Returns 'n' number of least used entries present in this cache. |
| * <p> |
| * This uses a TreeSet to collect the 'n' least used items ordered by ascending hitcount |
| * and returns a LinkedHashMap containing 'n' or less than 'n' entries. |
| * |
| * @param n the number of items needed |
| * @return a LinkedHashMap containing 'n' or less than 'n' entries |
| */ |
| public Map<K, V> getLeastUsedItems(int n) { |
| Map<K, V> result = new LinkedHashMap<>(); |
| if (n <= 0) |
| return result; |
| TreeSet<CacheEntry<K, V>> tree = new TreeSet<>(); |
| // we need to grab the lock since we are changing the copy variables |
| markAndSweepLock.lock(); |
| try { |
| for (Map.Entry<Object, CacheEntry<K, V>> entry : map.entrySet()) { |
| CacheEntry<K, V> ce = entry.getValue(); |
| ce.hitsCopy = ce.hits.longValue(); |
| ce.lastAccessedCopy = ce.lastAccessed; |
| if (tree.size() < n) { |
| tree.add(ce); |
| } else { |
| // If the hits are not equal, we can remove before adding |
| // which is slightly faster |
| if (ce.hitsCopy < tree.first().hitsCopy) { |
| tree.remove(tree.first()); |
| tree.add(ce); |
| } else if (ce.hitsCopy == tree.first().hitsCopy) { |
| tree.add(ce); |
| tree.remove(tree.first()); |
| } |
| } |
| } |
| } finally { |
| markAndSweepLock.unlock(); |
| } |
| for (CacheEntry<K, V> e : tree) { |
| result.put(e.key, e.value); |
| } |
| return result; |
| } |
| |
| /** |
| * Returns 'n' number of most used entries present in this cache. |
| * <p> |
| * This uses a TreeSet to collect the 'n' most used items ordered by descending hitcount |
| * and returns a LinkedHashMap containing 'n' or less than 'n' entries. |
| * |
| * @param n the number of items needed |
| * @return a LinkedHashMap containing 'n' or less than 'n' entries |
| */ |
| public Map<K, V> getMostUsedItems(int n) { |
| Map<K, V> result = new LinkedHashMap<>(); |
| if (n <= 0) |
| return result; |
| TreeSet<CacheEntry<K, V>> tree = new TreeSet<>(); |
| // we need to grab the lock since we are changing the copy variables |
| markAndSweepLock.lock(); |
| try { |
| for (Map.Entry<Object, CacheEntry<K, V>> entry : map.entrySet()) { |
| CacheEntry<K, V> ce = entry.getValue(); |
| ce.hitsCopy = ce.hits.longValue(); |
| ce.lastAccessedCopy = ce.lastAccessed; |
| if (tree.size() < n) { |
| tree.add(ce); |
| } else { |
| // If the hits are not equal, we can remove before adding |
| // which is slightly faster |
| if (ce.hitsCopy > tree.last().hitsCopy) { |
| tree.remove(tree.last()); |
| tree.add(ce); |
| } else if (ce.hitsCopy == tree.last().hitsCopy) { |
| tree.add(ce); |
| tree.remove(tree.last()); |
| } |
| } |
| } |
| } finally { |
| markAndSweepLock.unlock(); |
| } |
| for (CacheEntry<K, V> e : tree) { |
| result.put(e.key, e.value); |
| } |
| return result; |
| } |
| |
| public int size() { |
| return stats.size.intValue(); |
| } |
| |
| @Override |
| public void clear() { |
| map.clear(); |
| ramBytes.reset(); |
| } |
| |
| public Map<Object, CacheEntry<K, V>> getMap() { |
| return map; |
| } |
| |
| @Override |
| public long ramBytesUsed() { |
| return BASE_RAM_BYTES_USED + ramBytes.sum(); |
| } |
| |
| public static class CacheEntry<K, V> implements Comparable<CacheEntry<K, V>>, Accountable { |
| public static final long BASE_RAM_BYTES_USED = RamUsageEstimator.shallowSizeOfInstance(CacheEntry.class) |
| // AtomicLong |
| + RamUsageEstimator.primitiveSizes.get(long.class); |
| |
| final K key; |
| final V value; |
| final long ramBytesUsed; |
| final LongAdder hits = new LongAdder(); |
| long hitsCopy = 0; |
| volatile long lastAccessed = 0; |
| long lastAccessedCopy = 0; |
| |
| public CacheEntry(K key, V value, long lastAccessed) { |
| this.key = key; |
| this.value = value; |
| this.lastAccessed = lastAccessed; |
| ramBytesUsed = BASE_RAM_BYTES_USED + |
| RamUsageEstimator.sizeOfObject(key, QUERY_DEFAULT_RAM_BYTES_USED) + |
| RamUsageEstimator.sizeOfObject(value, QUERY_DEFAULT_RAM_BYTES_USED); |
| } |
| |
| @Override |
| public int compareTo(CacheEntry<K, V> that) { |
| if (this.hitsCopy == that.hitsCopy) { |
| if (this.lastAccessedCopy == that.lastAccessedCopy) { |
| return 0; |
| } |
| return this.lastAccessedCopy < that.lastAccessedCopy ? 1 : -1; |
| } |
| return this.hitsCopy < that.hitsCopy ? 1 : -1; |
| } |
| |
| @Override |
| public int hashCode() { |
| return value.hashCode(); |
| } |
| |
| @Override |
| public boolean equals(Object obj) { |
| return value.equals(obj); |
| } |
| |
| @Override |
| public String toString() { |
| return "key: " + key + " value: " + value + " hits:" + hits.longValue(); |
| } |
| |
| @Override |
| public long ramBytesUsed() { |
| return ramBytesUsed; |
| } |
| } |
| |
| private boolean isDestroyed = false; |
| |
| public void destroy() { |
| try { |
| if (cleanupThread != null) { |
| cleanupThread.stopThread(); |
| } |
| } finally { |
| isDestroyed = true; |
| } |
| } |
| |
| public Stats getStats() { |
| return stats; |
| } |
| |
| |
| public static class Stats implements Accountable { |
| private static final long RAM_BYTES_USED = |
| RamUsageEstimator.shallowSizeOfInstance(Stats.class) + |
| // LongAdder |
| 7 * ( |
| RamUsageEstimator.NUM_BYTES_ARRAY_HEADER + |
| RamUsageEstimator.primitiveSizes.get(long.class) + |
| 2 * (RamUsageEstimator.NUM_BYTES_OBJECT_REF + RamUsageEstimator.primitiveSizes.get(long.class)) |
| ); |
| |
| private final LongAdder accessCounter = new LongAdder(); |
| private final LongAdder putCounter = new LongAdder(); |
| private final LongAdder nonLivePutCounter = new LongAdder(); |
| private final LongAdder missCounter = new LongAdder(); |
| private final LongAdder size = new LongAdder(); |
| private LongAdder evictionCounter = new LongAdder(); |
| private LongAdder evictionIdleCounter = new LongAdder(); |
| |
| public long getCumulativeLookups() { |
| return (accessCounter.longValue() - putCounter.longValue() - nonLivePutCounter.longValue()) + missCounter.longValue(); |
| } |
| |
| public long getCumulativeHits() { |
| return accessCounter.longValue() - putCounter.longValue() - nonLivePutCounter.longValue(); |
| } |
| |
| public long getCumulativePuts() { |
| return putCounter.longValue(); |
| } |
| |
| public long getCumulativeEvictions() { |
| return evictionCounter.longValue(); |
| } |
| |
| public long getCumulativeIdleEvictions() { |
| return evictionIdleCounter.longValue(); |
| } |
| |
| public int getCurrentSize() { |
| return size.intValue(); |
| } |
| |
| public long getCumulativeNonLivePuts() { |
| return nonLivePutCounter.longValue(); |
| } |
| |
| public long getCumulativeMisses() { |
| return missCounter.longValue(); |
| } |
| |
| public void add(Stats other) { |
| accessCounter.add(other.accessCounter.longValue()); |
| putCounter.add(other.putCounter.longValue()); |
| nonLivePutCounter.add(other.nonLivePutCounter.longValue()); |
| missCounter.add(other.missCounter.longValue()); |
| evictionCounter.add(other.evictionCounter.longValue()); |
| evictionIdleCounter.add(other.evictionIdleCounter.longValue()); |
| long maxSize = Math.max(size.longValue(), other.size.longValue()); |
| size.reset(); |
| size.add(maxSize); |
| } |
| |
| @Override |
| public long ramBytesUsed() { |
| return RAM_BYTES_USED; |
| } |
| } |
| |
| public static interface EvictionListener<K, V> { |
| public void evictedEntry(K key, V value); |
| } |
| |
| private static class CleanupThread extends Thread { |
| private WeakReference<ConcurrentLFUCache> cache; |
| |
| private boolean stop = false; |
| |
| public CleanupThread(ConcurrentLFUCache c) { |
| cache = new WeakReference<>(c); |
| } |
| |
| @Override |
| public void run() { |
| while (true) { |
| ConcurrentLFUCache c = cache.get(); |
| if(c == null) break; |
| synchronized (this) { |
| if (stop) break; |
| long waitTimeMs = c.maxIdleTimeNs != Long.MAX_VALUE ? TimeUnit.MILLISECONDS.convert(c.maxIdleTimeNs, TimeUnit.NANOSECONDS) : 0L; |
| try { |
| this.wait(waitTimeMs); |
| } catch (InterruptedException e) { |
| } |
| } |
| if (stop) break; |
| c = cache.get(); |
| if (c == null) break; |
| c.markAndSweep(); |
| } |
| } |
| |
| void wakeThread() { |
| synchronized (this) { |
| this.notify(); |
| } |
| } |
| |
| void stopThread() { |
| synchronized (this) { |
| stop = true; |
| this.notify(); |
| } |
| } |
| } |
| |
| @Override |
| protected void finalize() throws Throwable { |
| try { |
| if (!isDestroyed) { |
| log.error("ConcurrentLFUCache was not destroyed prior to finalize(), indicates a bug -- POSSIBLE RESOURCE LEAK!!!"); |
| destroy(); |
| } |
| } finally { |
| super.finalize(); |
| } |
| } |
| } |