SetAdapter.java

/*
 * Copyright (c) [2016] [ <ether.camp> ]
 * This file is part of the ethereumJ library.
 *
 * The ethereumJ library 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.
 *
 * The ethereumJ library 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 the ethereumJ library. If not, see <http://www.gnu.org/licenses/>.
 */
package org.ethereum.util;

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

/**
 * Created by Anton Nashatyrev on 06.10.2016.
 */
public class SetAdapter<E> implements Set<E> {
    private static final Object DummyValue = new Object();
    Map<E, Object> delegate;

    public SetAdapter(Map<E, ?> delegate) {
        this.delegate = (Map<E, Object>) delegate;
    }

    @Override
    public int size() {
        return delegate.size();
    }

    @Override
    public boolean isEmpty() {
        return delegate.isEmpty();
    }

    @Override
    public boolean contains(Object o) {
        return delegate.containsKey(o);
    }

    @Override
    public Iterator<E> iterator() {
        return delegate.keySet().iterator();
    }

    @Override
    public Object[] toArray() {
        return delegate.keySet().toArray();
    }

    @Override
    public <T> T[] toArray(T[] a) {
        return delegate.keySet().toArray(a);
    }

    @Override
    public boolean add(E e) {
        return delegate.put(e, DummyValue) == null;
    }

    @Override
    public boolean remove(Object o) {
        return delegate.remove(o) != null;
    }

    @Override
    public boolean containsAll(Collection<?> c) {
        return delegate.keySet().containsAll(c);
    }

    @Override
    public boolean addAll(Collection<? extends E> c) {
        boolean ret = false;
        for (E e : c) {
            ret |= add(e);
        }
        return ret;
    }

    @Override
    public boolean retainAll(Collection<?> c) {
        throw new RuntimeException("Not implemented"); // TODO add later if required
    }

    @Override
    public boolean removeAll(Collection<?> c) {
        boolean ret = false;
        for (Object e : c) {
            ret |= remove(e);
        }
        return ret;
    }

    @Override
    public void clear() {
        delegate.clear();
    }
}