shade.io.netty.util.internal.shaded.org.jctools.maps.NonBlockingHashSet Maven / Gradle / Ivy
/*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package io.netty.util.internal.shaded.org.jctools.maps;
import java.io.Serializable;
import java.util.AbstractSet;
import java.util.Iterator;
import java.util.Set;
/**
* A simple wrapper around {@link NonBlockingHashMap} making it implement the
* {@link Set} interface. All operations are Non-Blocking and multi-thread safe.
*
* @since 1.5
* @author Cliff Click
*/
public class NonBlockingHashSet extends AbstractSet implements Serializable {
private static final Object V = "";
private final NonBlockingHashMap _map;
/** Make a new empty {@link NonBlockingHashSet}. */
public NonBlockingHashSet() { super(); _map = new NonBlockingHashMap(); }
/** Add {@code o} to the set.
* @return true if {@code o} was added to the set, false
* if {@code o} was already in the set. */
public boolean add( final E o ) { return _map.putIfAbsent(o,V) == null; }
/** @return true if {@code o} is in the set. */
public boolean contains ( final Object o ) { return _map.containsKey(o); }
/** @return Returns the match for {@code o} if {@code o} is in the set. */
public E get( final E o ) { return _map.getk(o); }
/** Remove {@code o} from the set.
* @return true if {@code o} was removed to the set, false
* if {@code o} was not in the set.
*/
public boolean remove( final Object o ) { return _map.remove(o) == V; }
/** Current count of elements in the set. Due to concurrent racing updates,
* the size is only ever approximate. Updates due to the calling thread are
* immediately visible to calling thread.
* @return count of elements. */
public int size( ) { return _map.size(); }
/** Empty the set. */
public void clear( ) { _map.clear(); }
public Iteratoriterator( ) { return _map.keySet().iterator(); }
}