| /* |
| * Copyright 2014 Paul Merlin. |
| * |
| * Licensed 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.qi4j.cache.memcache; |
| |
| import java.util.concurrent.atomic.AtomicInteger; |
| import net.spy.memcached.MemcachedClient; |
| import net.spy.memcached.transcoders.SerializingTranscoder; |
| import org.qi4j.spi.cache.Cache; |
| |
| /** |
| * Memcache Implementation. |
| * Use Java Serialization under the hood. |
| * @param <T> Parameterized Type of cached entries |
| */ |
| /* package */ class MemcacheImpl<T> |
| implements Cache<T> |
| { |
| private static final AtomicInteger INSTANCES = new AtomicInteger(); |
| private final MemcachedClient client; |
| private final String cacheId; |
| private final String cachePrefix; |
| private final Class<T> valueType; |
| private final int expiration; |
| private int refCount; |
| |
| /* package */ MemcacheImpl( MemcachedClient client, String cacheId, Class<T> valueType, int expiration ) |
| { |
| this.client = client; |
| this.cacheId = cacheId; |
| this.cachePrefix = cacheId + "." + INSTANCES.incrementAndGet() + "."; |
| this.valueType = valueType; |
| this.expiration = expiration; |
| } |
| |
| @Override |
| public T get( String key ) |
| { |
| Object value = client.get( prefix( key ), new SerializingTranscoder() ); |
| client.touch( prefix( key ), expiration ); |
| if( value == null ) |
| { |
| return null; |
| } |
| return valueType.cast( value ); |
| } |
| |
| @Override |
| public T remove( String key ) |
| { |
| String prefixedKey = prefix( key ); |
| Object old = client.get( prefixedKey, new SerializingTranscoder() ); |
| if( old != null ) |
| { |
| client.delete( prefixedKey ); |
| } |
| return valueType.cast( old ); |
| } |
| |
| @Override |
| public void put( String key, T value ) |
| { |
| client.set( prefix( key ), expiration, value, new SerializingTranscoder() ); |
| } |
| |
| @Override |
| public boolean exists( String key ) |
| { |
| return client.get( prefix( key ) ) != null; |
| } |
| |
| private String prefix( String key ) |
| { |
| return cachePrefix + key; |
| } |
| |
| synchronized void decRefCount() |
| { |
| refCount--; |
| } |
| |
| synchronized void incRefCount() |
| { |
| refCount++; |
| } |
| |
| synchronized boolean isNotUsed() |
| { |
| return refCount == 0; |
| } |
| |
| public String cacheId() |
| { |
| return cacheId; |
| } |
| } |