com.davidbracewell.cache.impl.GuavaLoadingCache.java Source code

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Here is the source code for com.davidbracewell.cache.impl.GuavaLoadingCache.java

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/*
 * (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.impl;

import com.davidbracewell.cache.AutoCalculatingCache;
import com.davidbracewell.cache.CacheSpec;
import com.google.common.base.Preconditions;
import com.google.common.base.Throwables;
import com.google.common.cache.CacheBuilder;
import com.google.common.cache.CacheLoader;
import com.google.common.cache.LoadingCache;

import java.util.concurrent.ExecutionException;

/**
 * @author David B. Bracewell
 */
public class GuavaLoadingCache<K, V> extends AutoCalculatingCache<K, V> {

    private final LoadingCache<K, V> cache;

    public GuavaLoadingCache(CacheSpec<K, V> specification) {
        super(Preconditions.checkNotNull(specification));
        Preconditions.checkNotNull(specification.getFunction());
        CacheBuilder<K, V> cacheBuilder = GuavaCacheUtils.cacheBuilderFromSpec(specification);
        CacheLoader<K, V> loader = new CacheLoader<K, V>() {
            @Override
            public V load(K key) throws Exception {
                return function.apply(key);
            }
        };
        if (specification.getRemovalListener() == null) {
            this.cache = cacheBuilder.build(loader);
        } else {
            this.cache = cacheBuilder.removalListener(specification.getRemovalListener()).build(loader);
        }
    }

    @Override
    public boolean containsKey(K key) {
        return cache.asMap().containsKey(key);
    }

    @Override
    public void put(K key, final V value) {
        cache.put(key, value);
    }

    @Override
    public long size() {
        return cache.size();
    }

    @Override
    public void invalidateAll() {
        cache.invalidateAll();
    }

    @Override
    public void invalidateAll(Iterable<? extends K> keys) {
        cache.invalidateAll(keys);
    }

    @Override
    public void invalidate(K key) {
        cache.invalidate(key);
    }

    @Override
    public void close() throws Exception {
        cache.cleanUp();
    }

    @Override
    public V get(K key) {
        try {
            return cache.get(key);
        } catch (ExecutionException e) {
            throw Throwables.propagate(e);
        }
    }

    @Override
    public void refresh(K key) throws ExecutionException {
        cache.refresh(key);
    }

}//END OF GuavaCache