ChronicleMapEntrySet.java

/*
 *      Copyright (C) 2012, 2016  higherfrequencytrading.com
 *      Copyright (C) 2016 Roman Leventov
 *
 *      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.
 *
 *      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, see <http://www.gnu.org/licenses/>.
 */

package net.openhft.chronicle.map;

import org.jetbrains.annotations.NotNull;

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

class ChronicleMapEntrySet<K, V> extends AbstractSet<Map.Entry<K, V>> {

    private final AbstractChronicleMap<K, V> map;

    public ChronicleMapEntrySet(AbstractChronicleMap<K, V> map) {
        this.map = map;
    }

    @NotNull
    public Iterator<Map.Entry<K, V>> iterator() {
        return new ChronicleMapIterator.OfEntries<>(map);
    }

    public final boolean contains(Object o) {
        if (!(o instanceof Map.Entry))
            return false;
        Map.Entry<?, ?> e = (Map.Entry<?, ?>) o;
        try {
            V v = map.get(e.getKey());
            return v != null && v.equals(e.getValue());
        } catch (ClassCastException ex) {
            return false;
        } catch (NullPointerException ex) {
            return false;
        }
    }

    public final boolean remove(Object o) {
        if (!(o instanceof Map.Entry))
            return false;
        Map.Entry<?, ?> e = (Map.Entry<?, ?>) o;
        try {
            Object key = e.getKey();
            Object value = e.getValue();
            return map.remove(key, value);
        } catch (ClassCastException ex) {
            return false;
        } catch (NullPointerException ex) {
            return false;
        }
    }

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

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

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