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/*
 * Copyright (c) 2015, Gluon
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 *     * Neither the name of Gluon, any associated website, nor the
 * names of its contributors may be used to endorse or promote products
 * derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL GLUON BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package com.gluonhq.charm.down.common.cache;

import java.lang.ref.SoftReference;
import java.util.HashMap;
import java.util.Map;

/**
 *
 * @param  type for the key
 * @param  type for the value
 */
public class DefaultCache implements Cache {

    private Map> map = new HashMap<>();

    public DefaultCache () {
    }
    
    @Override
    public V get(K key) {
        SoftReference ref = map.get(key);
        if (ref != null) {
            return ref.get();
        }
        return null;
    }

    @Override
    public void put(K key, V value) {
        if (key == null) {
            throw new NullPointerException ("Cache key should not be null");
        }
        if (value == null) {
            throw new NullPointerException ("Cache value should not be null");
        }
        SoftReference ref = new SoftReference<>(value);
        map.put(key, ref);
    }

    @Override
    public boolean remove(K key) {
        boolean answer = map.containsKey(key);
        map.remove(key);
        return answer;
    }

    @Override
    public void removeAll() {
        map.clear();
    }

}