/**
 * This is free and unencumbered software released into the public domain.
 *
 * Anyone is free to copy, modify, publish, use, compile, sell, or
 * distribute this software, either in source code form or as a compiled
 * binary, for any purpose, commercial or non-commercial, and by any
 * means.
 *
 * In jurisdictions that recognize copyright laws, the author or authors
 * of this software dedicate any and all copyright interest in the
 * software to the public domain. We make this dedication for the benefit
 * of the public at large and to the detriment of our heirs and
 * successors. We intend this dedication to be an overt act of
 * relinquishment in perpetuity of all present and future rights to this
 * software under copyright law.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 *
 * For more information, please refer to <http://unlicense.org/>
 */
package com.imaginarycode.minecraft.redisbungee.util;

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

// I would use the Guava, but can't because I need a few more properties.
public class InternalCache<K, V> {
    private final ConcurrentMap<K, V> map = new ConcurrentHashMap<>(128, 0.75f, 4);

    public V get(K key, Callable<V> loader) throws ExecutionException {
        V value = map.get(key);

        if (value == null) {
            try {
                value = loader.call();
            } catch (Exception e) {
                throw new ExecutionException(e);
            }

            if (value == null)
                return null;

            map.putIfAbsent(key, value);
        }

        return value;
    }

    public V put(K key, V value) {
        return map.put(key, value);
    }

    public void invalidate(K key) {
        map.remove(key);
    }
}