/*
* Copyright 2015 Ben Manes. All Rights Reserved.
*
* 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.github.benmanes.caffeine.guava;
import java.lang.reflect.Method;
import javax.annotation.Nonnull;
import com.github.benmanes.caffeine.cache.Caffeine;
import com.github.benmanes.caffeine.guava.CaffeinatedGuavaLoadingCache.BulkLoader;
import com.github.benmanes.caffeine.guava.CaffeinatedGuavaLoadingCache.SingleLoader;
import com.google.common.cache.Cache;
import com.google.common.cache.CacheLoader;
import com.google.common.cache.LoadingCache;
/**
* An adapter to expose a Caffeine cache through the Guava interfaces.
*
* @author ben.manes@gmail.com (Ben Manes)
*/
public final class CaffeinatedGuava {
private CaffeinatedGuava() {}
/**
* Returns a Caffeine cache wrapped in a Guava {@link Cache} facade.
*
* @param builder the configured cache builder
* @return a cache exposed under the Guava APIs
*/
@Nonnull
public static <K, V, K1 extends K, V1 extends V> Cache<K1, V1> build(
@Nonnull Caffeine<K, V> builder) {
return new CaffeinatedGuavaCache<>(builder.build());
}
/**
* Returns a Caffeine cache wrapped in a Guava {@link LoadingCache} facade.
*
* @param builder the configured cache builder
* @param loader the cache loader used to obtain new values
* @return a cache exposed under the Guava APIs
*/
@Nonnull
public static <K, V, K1 extends K, V1 extends V> LoadingCache<K1, V1> build(
@Nonnull Caffeine<K, V> builder, @Nonnull CacheLoader<? super K1, V1> loader) {
@SuppressWarnings("unchecked")
CacheLoader<K1, V1> castedLoader = (CacheLoader<K1, V1>) loader;
return build(builder, hasLoadAll(castedLoader)
? new BulkLoader<>(castedLoader)
: new SingleLoader<>(castedLoader));
}
/**
* Returns a Caffeine cache wrapped in a Guava {@link LoadingCache} facade.
*
* @param builder the configured cache builder
* @param loader the cache loader used to obtain new values
* @return a cache exposed under the Guava APIs
*/
@Nonnull
public static <K, V, K1 extends K, V1 extends V> LoadingCache<K1, V1> build(
@Nonnull Caffeine<K, V> builder,
@Nonnull com.github.benmanes.caffeine.cache.CacheLoader<? super K1, V1> loader) {
return new CaffeinatedGuavaLoadingCache<>(builder.build(loader));
}
static boolean hasLoadAll(CacheLoader<?, ?> cacheLoader) {
return hasMethod(cacheLoader, "loadAll", Iterable.class);
}
static boolean hasMethod(CacheLoader<?, ?> cacheLoader, String name, Class<?>... paramTypes) {
try {
Method method = cacheLoader.getClass().getMethod(name, paramTypes);
return (method.getDeclaringClass() != CacheLoader.class);
} catch (NoSuchMethodException | SecurityException e) {
return false;
}
}
}