SquirrelJME/SquirrelJME

// -*- Mode: Java; indent-tabs-mode: t; tab-width: 4 -*-
// ---------------------------------------------------------------------------
// SquirrelJME
//     Copyright (C) Stephanie Gawroriski <xer@multiphasicapps.net>
// ---------------------------------------------------------------------------
// SquirrelJME is under the Mozilla Public License Version 2.0.
// See license.mkd for licensing and copyright information.
// ---------------------------------------------------------------------------

package cc.squirreljme.runtime.cldc.util;

import java.util.AbstractSet;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;

/**
 * This is an entry set which is synchronized against a lock, null values
 * are not allowed.
 *
 * @param <K> The entry keys.
 * @param <V> The entry values.
 * @since 2019/05/05
 */
public final class SynchronizedEntrySetNotNull<K, V>
    extends AbstractSet<Map.Entry<K, V>>
{
    /** The locking object. */
    protected final Object lock;
    
    /** The backing set. */
    protected final Set<Map.Entry<K, V>> set;
    
    /**
     * Initializes the synchronized entry set.
     *
     * @param __lock The locking object.
     * @param __set The entry set object.
     * @throws NullPointerException On null arguments.
     * @since 2019/05/05
     */
    public SynchronizedEntrySetNotNull(Object __lock,
        Set<Map.Entry<K, V>> __set)
        throws NullPointerException
    {
        if (__lock == null || __set == null)
            throw new NullPointerException("NARG");
        
        this.lock = __lock;
        this.set = __set;
    }
    
    /**
     * {@inheritDoc}
     * @since 2019/05/05
     */
    @Override
    public final Iterator<Map.Entry<K, V>> iterator()
    {
        Object lock = this.lock;
        synchronized (lock)
        {
            return new SynchronizedEntrySetIteratorNotNull<K, V>(
                lock, this.set.iterator());
        }
    }
    
    /**
     * {@inheritDoc}
     * @since 2019/05/05
     */
    @Override
    public final int size()
    {
        synchronized (this.lock)
        {
            return this.set.size();
        }
    }
}