forgot to add the actual ConcurrentHashSet

src/main/java/com/corundumstudio/socketio/utils/ConcurrentHashSet.java

@@ -0,0 +1,98 @@
+/**
+ * Copyright 2012 Nikita Koksharov
+ *
+ * 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 com.corundumstudio.socketio.utils;
+
+import java.util.AbstractSet;
+import java.util.Collection;
+import java.util.Iterator;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+
+/**
+ * Adapter for ConcurrentHashMap, a-la jdk 1.6+ Collections.newSetFromMap(new ConcurrentHashMap....) idiom
+ * @author radu.cirstoiu@gmail.com
+ */
+public class ConcurrentHashSet<E> extends AbstractSet<E> implements Set<E> {
+	private final Map<E, Boolean> backingMap;
+	private final Set<E> backingMapSet;
+
+	public ConcurrentHashSet() {
+		backingMap = (new ConcurrentHashMap<E, Boolean>());
+		backingMapSet = backingMap.keySet();
+	}
+
+	public int size() {
+		return backingMap.size();
+	}
+
+	public boolean isEmpty() {
+		return backingMap.isEmpty();
+	}
+
+	public boolean contains(Object o) {
+		return backingMap.containsKey(o);
+	}
+
+	public Iterator<E> iterator() {
+		return backingMapSet.iterator();
+	}
+
+	public void clear() {
+		backingMap.clear();
+	}
+
+	public Object[] toArray() {
+		return backingMapSet.toArray();
+	}
+
+	public <T> T[] toArray(T[] a) {
+		return backingMapSet.toArray(a);
+	}
+
+	public boolean add(E e) {
+		return backingMap.put(e, Boolean.TRUE) == null;
+	}
+
+	public boolean remove(Object o) {
+		return backingMap.remove(o) != null;
+	}
+
+	public boolean containsAll(Collection<?> c) {
+		return backingMapSet.containsAll(c);
+	}
+
+	public boolean removeAll(Collection<?> c) {
+		return backingMapSet.removeAll(c);
+	}
+
+	public boolean retainAll(Collection<?> c) {
+		return backingMapSet.retainAll(c);
+	}
+
+	public String toString() {
+		return backingMapSet.toString();
+	}
+
+	public int hashCode() {
+		return backingMapSet.hashCode();
+	}
+
+	public boolean equals(Object o) {
+		return o == this || backingMapSet.equals(o);
+	}
+
+}