| /* |
| * Copyright (c) OSGi Alliance (2017). All Rights Reserved. |
| * |
| * 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 org.osgi.util.converter; |
| |
| import java.lang.reflect.Array; |
| import java.util.Arrays; |
| import java.util.Collection; |
| import java.util.Collections; |
| import java.util.HashSet; |
| import java.util.Iterator; |
| import java.util.List; |
| import java.util.Set; |
| |
| /** |
| * @author $Id$ |
| */ |
| class SetDelegate<T> implements Set<T> { |
| private volatile Set<T> delegate; |
| private volatile boolean cloned; |
| private final ConvertingImpl convertingImpl; |
| |
| static <T> Set<T> forCollection(Collection<T> collection, |
| ConvertingImpl converting) { |
| if (collection instanceof Set) { |
| return new SetDelegate<T>((Set<T>) collection, converting); |
| } |
| return new SetDelegate<T>(new CollectionSetDelegate<>(collection), |
| converting); |
| } |
| |
| SetDelegate(Set<T> collection, ConvertingImpl converting) { |
| delegate = collection; |
| convertingImpl = converting; |
| } |
| |
| // Whenever a modification is made, the delegate is cloned and detached. |
| private void cloneDelegate() { |
| if (cloned) { |
| return; |
| } else { |
| cloned = true; |
| delegate = new HashSet<>(delegate); |
| } |
| } |
| |
| @Override |
| public int size() { |
| return delegate.size(); |
| } |
| |
| @Override |
| public boolean isEmpty() { |
| return delegate.isEmpty(); |
| } |
| |
| @Override |
| public boolean contains(Object o) { |
| return containsAll(Collections.singletonList(o)); |
| } |
| |
| @Override |
| public Iterator<T> iterator() { |
| return new SetDelegateIterator(); |
| } |
| |
| @Override |
| public Object[] toArray() { |
| return toArray(new Object[size()]); |
| } |
| |
| @SuppressWarnings("unchecked") |
| @Override |
| public <X> X[] toArray(X[] a) { |
| int mySize = size(); |
| if (Array.getLength(a) < size()) { |
| a = (X[]) Array.newInstance(a.getClass().getComponentType(), |
| mySize); |
| } |
| |
| Iterator<T> it = iterator(); |
| for (int i = 0; i < a.length; i++) { |
| if (mySize > i && it.hasNext()) { |
| a[i] = (X) it.next(); |
| } else { |
| a[i] = null; |
| } |
| } |
| return a; |
| } |
| |
| @Override |
| public boolean add(T e) { |
| cloneDelegate(); |
| |
| return delegate.add(e); |
| } |
| |
| @Override |
| public boolean remove(Object o) { |
| cloneDelegate(); |
| |
| return delegate.remove(o); |
| } |
| |
| @Override |
| public boolean containsAll(Collection< ? > c) { |
| List<Object> l = Arrays.asList(toArray()); |
| for (Object o : c) { |
| if (!l.contains(o)) |
| return false; |
| } |
| |
| return true; |
| } |
| |
| @Override |
| public boolean addAll(Collection< ? extends T> c) { |
| cloneDelegate(); |
| |
| return delegate.addAll(c); |
| } |
| |
| @Override |
| public boolean retainAll(Collection< ? > c) { |
| cloneDelegate(); |
| |
| return delegate.retainAll(c); |
| } |
| |
| @Override |
| public boolean removeAll(Collection< ? > c) { |
| cloneDelegate(); |
| |
| return delegate.removeAll(c); |
| } |
| |
| @Override |
| public int hashCode() { |
| return delegate.hashCode(); |
| } |
| |
| @Override |
| public boolean equals(Object obj) { |
| if (obj == this) |
| return true; |
| if (!(obj instanceof Set)) |
| return false; |
| |
| Set< ? > s1 = new HashSet<>(this); |
| Set< ? > s2 = new HashSet<>((Set< ? >) obj); |
| return s1.equals(s2); |
| // cannot call delegate.equals() because they are of different types |
| } |
| |
| @Override |
| public String toString() { |
| return delegate.toString(); |
| } |
| |
| @Override |
| public void clear() { |
| cloned = true; |
| delegate = new HashSet<>(); |
| } |
| |
| private class SetDelegateIterator implements Iterator<T> { |
| final Iterator< ? > delegateIterator; |
| |
| @SuppressWarnings("synthetic-access") |
| SetDelegateIterator() { |
| delegateIterator = delegate.iterator(); |
| } |
| |
| @Override |
| public boolean hasNext() { |
| return delegateIterator.hasNext(); |
| } |
| |
| @SuppressWarnings({ |
| "unchecked", "synthetic-access" |
| }) |
| @Override |
| public T next() { |
| Object obj = delegateIterator.next(); |
| return (T) convertingImpl.convertCollectionValue(obj); |
| } |
| |
| @Override |
| public void remove() { |
| throw new UnsupportedOperationException("remove"); |
| } |
| } |
| } |