/**
 * This file is part of the Meeds project (https://meeds.io/).
 *
 * Copyright (C) 2020 - 2025 Meeds Association contact@meeds.io
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 3 of the License, or (at your option) any later version.
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 */
package org.exoplatform.services.cache.future;

/**
 * The loader interface is used by the future cache to retrieves the value from the key when it does not exist.
 *
 */
public interface Loader<K, V, C>
{

   /**
    * Retrieves the value from the key within the specified context. If the resource is not found then the value
    * null must be returned.
    *
    * @param context the context
    * @param key the key
    * @return the value
    * @throws Exception any exception that would prevent the value to be loaded
    */
   V retrieve(C context, K key) throws Exception;

}
