com.davidbracewell.cache.GuavaCacheEngine Maven / Gradle / Ivy

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A set of utilities and tools to speed up and ease programming in Java.
There is a newer version: 0.5
/*
 * (c) 2005 David B. Bracewell
 *
 * 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 com.davidbracewell.cache;

import com.davidbracewell.conversion.Cast;
import com.google.common.cache.CacheBuilder;
import lombok.NonNull;
import org.kohsuke.MetaInfServices;

import java.util.concurrent.TimeUnit;

/**
 * @author David B. Bracewell
 */
@MetaInfServices
public class GuavaCacheEngine implements CacheEngine {

  @Override
  public String name() {
    return "Guava";
  }

  @Override
  @SuppressWarnings("unchecked")
  public  Cache create(@NonNull CacheSpec cacheSpec) {
    CacheBuilder builder = cacheBuilderFromSpec(cacheSpec);
    if (cacheSpec.getLoadingFunction() == null) {
      return new GuavaCache<>(cacheSpec.getName(), builder);
    }
    return new GuavaLoadingCache<>(cacheSpec.getName(), builder, cacheSpec.getLoadingFunction());
  }

  @SuppressWarnings("unchecked")
  private  CacheBuilder cacheBuilderFromSpec(CacheSpec specification) {
    CacheBuilder cacheBuilder = CacheBuilder.newBuilder();
    if (specification.getMaxSize() > 0) {
      cacheBuilder.maximumSize(specification.getMaxSize());
    }
    if (specification.getConcurrencyLevel() > 0) {
      cacheBuilder.concurrencyLevel(specification.getMaxSize());
    }
    if (specification.getInitialCapacity() > 0) {
      cacheBuilder.initialCapacity(specification.getInitialCapacity());
    }
    if (specification.getExpiresAfterAccess() > 0) {
      cacheBuilder.expireAfterAccess(specification.getExpiresAfterAccess(), TimeUnit.MILLISECONDS);
    }
    if (specification.getExpiresAfterWrite() > 0) {
      cacheBuilder.expireAfterWrite(specification.getExpiresAfterWrite(), TimeUnit.MILLISECONDS);
    }
    if (specification.isWeakKeys()) {
      cacheBuilder.weakKeys();
    }
    if (specification.isWeakValues()) {
      cacheBuilder.weakValues();
    }
    if (specification.getRemovalListener() != null) {
      cacheBuilder.removalListener(specification.getRemovalListener());
    }
    return Cast.as(cacheBuilder);
  }
}//END OF GuavaCacheEngine