package org.apache.jdbm;


import java.util.AbstractSet;
import java.util.Iterator;

/**
 * Wrapper for HTree to implement java.util.Map interface
 */
class HTreeSet<E> extends AbstractSet<E> {

    final HTree<E, Object> map;

    HTreeSet(HTree map) {
        this.map = map;
    }

    public Iterator<E> iterator() {
        return map.keySet().iterator();
    }

    public int size() {
        return map.size();
    }


    public boolean isEmpty() {
        return map.isEmpty();
    }

    public boolean contains(Object o) {
        return map.containsKey(o);
    }

    public boolean add(E e) {
        return map.put(e, Utils.EMPTY_STRING) == null;
    }

    public boolean remove(Object o) {
        return map.remove(o) == Utils.EMPTY_STRING;
    }

    public void clear() {
        map.clear();
    }

}