| /* |
| * 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.cassandra.cache; |
| |
| import java.util.Iterator; |
| |
| import com.googlecode.concurrentlinkedhashmap.ConcurrentLinkedHashMap; |
| import com.googlecode.concurrentlinkedhashmap.EntryWeigher; |
| |
| /** Wrapper so CLHM can implement ICache interface. |
| * (this is what you get for making library classes final.) */ |
| public class ConcurrentLinkedHashCache<K extends IMeasurableMemory, V extends IMeasurableMemory> implements ICache<K, V> |
| { |
| public static final int DEFAULT_CONCURENCY_LEVEL = 64; |
| private final ConcurrentLinkedHashMap<K, V> map; |
| |
| private ConcurrentLinkedHashCache(ConcurrentLinkedHashMap<K, V> map) |
| { |
| this.map = map; |
| } |
| |
| /** |
| * Initialize a cache with initial capacity with weightedCapacity |
| */ |
| public static <K extends IMeasurableMemory, V extends IMeasurableMemory> ConcurrentLinkedHashCache<K, V> create(long weightedCapacity, EntryWeigher<K, V> entryWeiger) |
| { |
| ConcurrentLinkedHashMap<K, V> map = new ConcurrentLinkedHashMap.Builder<K, V>() |
| .weigher(entryWeiger) |
| .maximumWeightedCapacity(weightedCapacity) |
| .concurrencyLevel(DEFAULT_CONCURENCY_LEVEL) |
| .build(); |
| |
| return new ConcurrentLinkedHashCache<>(map); |
| } |
| |
| public static <K extends IMeasurableMemory, V extends IMeasurableMemory> ConcurrentLinkedHashCache<K, V> create(long weightedCapacity) |
| { |
| return create(weightedCapacity, new EntryWeigher<K, V>() |
| { |
| public int weightOf(K key, V value) |
| { |
| long size = key.unsharedHeapSize() + value.unsharedHeapSize(); |
| assert size <= Integer.MAX_VALUE : "Serialized size cannot be more than 2GB/Integer.MAX_VALUE"; |
| return (int) size; |
| } |
| }); |
| } |
| |
| public long capacity() |
| { |
| return map.capacity(); |
| } |
| |
| public void setCapacity(long capacity) |
| { |
| map.setCapacity(capacity); |
| } |
| |
| public boolean isEmpty() |
| { |
| return map.isEmpty(); |
| } |
| |
| public int size() |
| { |
| return map.size(); |
| } |
| |
| public long weightedSize() |
| { |
| return map.weightedSize(); |
| } |
| |
| public void clear() |
| { |
| map.clear(); |
| } |
| |
| public V get(K key) |
| { |
| return map.get(key); |
| } |
| |
| public void put(K key, V value) |
| { |
| map.put(key, value); |
| } |
| |
| public boolean putIfAbsent(K key, V value) |
| { |
| return map.putIfAbsent(key, value) == null; |
| } |
| |
| public boolean replace(K key, V old, V value) |
| { |
| return map.replace(key, old, value); |
| } |
| |
| public void remove(K key) |
| { |
| map.remove(key); |
| } |
| |
| public Iterator<K> keyIterator() |
| { |
| return map.keySet().iterator(); |
| } |
| |
| public Iterator<K> hotKeyIterator(int n) |
| { |
| return map.descendingKeySetWithLimit(n).iterator(); |
| } |
| |
| public boolean containsKey(K key) |
| { |
| return map.containsKey(key); |
| } |
| } |