com.rhythm.louie.cache.GuavaBasicCache.java Source code

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Here is the source code for com.rhythm.louie.cache.GuavaBasicCache.java

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/* 
 * Copyright 2015 Rhythm & Hues Studios.
 *
 * 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 com.rhythm.louie.cache;

import com.google.common.cache.CacheBuilder;
import com.google.common.cache.CacheStats;
import com.google.common.collect.ImmutableMap;

import java.util.Map;
import java.util.concurrent.Callable;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.ExecutionException;

import com.google.common.cache.CacheBuilderSpec;

import org.slf4j.LoggerFactory;

/**
 * The basic Google Guava Cache wrapper
 * @author eyasukoc
 */
public class GuavaBasicCache<K, V> implements GuavaCache<K, V> {

    private final String cacheName;
    private final com.google.common.cache.Cache<K, V> cache;

    private GuavaBasicCache(String name, CacheBuilder<Object, Object> bldr) {
        this.cache = bldr.build();
        this.cacheName = name;
    }

    @SuppressWarnings("unchecked")
    public static <K, V> GuavaBasicCache<K, V> nonCaching(String name) {
        return new GuavaBasicCache(name, CacheBuilder.from(CacheBuilderSpec.disableCaching()));
    }

    @SuppressWarnings("unchecked")
    public static <K, V> GuavaBasicCache<K, V> permanent(String name) {
        return new GuavaBasicCache(name, CacheBuilder.newBuilder());
    }

    @SuppressWarnings("unchecked")
    public static <K, V> GuavaBasicCache<K, V> fromSpec(String name, CacheBuilderSpec spec) {
        return new GuavaBasicCache(name, CacheBuilder.from(spec));
    }

    @SuppressWarnings("unchecked")
    public static <K, V> GuavaBasicCache<K, V> fromSpec(String name, String spec) {
        return new GuavaBasicCache(name, CacheBuilder.from(spec));
    }

    @Override
    public com.google.common.cache.Cache<K, V> getGuava() {
        return this.cache;
    }

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

    /**
     * Returns the value if present, null otherwise
     * @param key
     * @return 
     */
    @Override
    public V get(K key) {
        return cache.getIfPresent(key);
    }

    @Override
    public V getIfPresent(K key) {
        return cache.getIfPresent(key);
    }

    @Override
    public V get(K key, Callable<? extends V> valueLoader) {
        try {
            return cache.get(key, valueLoader);
        } catch (ExecutionException e) {
            LoggerFactory.getLogger(GuavaBasicCache.class.getName())
                    .error("Failed to execute callable for guava cache 'get' miss.");
            return null;
        }
    }

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

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

    @Override
    public String getCacheName() {
        return cacheName;
    }

    @Override
    public void putAll(Map<K, V> map) throws Exception {
        cache.putAll(map);
    }

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

    /**
     * Performs any pending maintenance operations needed by the cache.
     */
    @Override
    public void cleanUp() {
        cache.cleanUp();
    }

    @Override
    public ConcurrentMap<K, V> asMap() {
        return cache.asMap();
    }

    @Override
    public ImmutableMap<K, V> getAllPresent(Iterable<?> keys) {
        return cache.getAllPresent(keys);
    }

    @Override
    public CacheStats getStats() {
        return cache.stats();
    }

    @Override
    public void refresh(K key) {
        throw new UnsupportedOperationException("Only supported by GuavaLoadingCache.");
    }

    /**
     * Unlike LoadingCache, this executes a getAllPresent
     * @param keys
     * @return
     * @throws ExecutionException 
     */
    @Override
    public ImmutableMap<K, V> getAll(Iterable<? extends K> keys) throws ExecutionException {
        return cache.getAllPresent(keys);
    }

}