package it.unimi.dsi.fastutil.objects;
import java.util.Collection;
import it.unimi.dsi.fastutil.objects.ObjectArrays;
public final class ReferenceCollections {
private ReferenceCollections() {
}
public abstract static class EmptyCollection<K> extends AbstractReferenceCollection<K> {
protected EmptyCollection() {
}
@Override
public boolean contains(Object k) {
return false;
}
@Override
public Object[] toArray() {
return ObjectArrays.EMPTY_ARRAY;
}
@Override
@SuppressWarnings("unchecked")
public ObjectBidirectionalIterator<K> iterator() {
return ObjectIterators.EMPTY_ITERATOR;
}
@Override
public int size() {
return 0;
}
@Override
public void clear() {
}
@Override
public int hashCode() {
return 0;
}
@Override
public boolean equals(Object o) {
if (o == this)
return true;
if (!(o instanceof Collection))
return false;
return ((Collection<?>) o).isEmpty();
}
@Override
public boolean addAll(final Collection<? extends K> c) {
throw new UnsupportedOperationException();
}
@Override
public boolean removeAll(final Collection<?> c) {
throw new UnsupportedOperationException();
}
@Override
public boolean retainAll(final Collection<?> c) {
throw new UnsupportedOperationException();
}
}
public static class SynchronizedCollection<K> implements ReferenceCollection<K>, java.io.Serializable {
private static final long serialVersionUID = -7046029254386353129L;
protected final ReferenceCollection<K> collection;
protected final Object sync;
protected SynchronizedCollection(final ReferenceCollection<K> c, final Object sync) {
if (c == null)
throw new NullPointerException();
this.collection = c;
this.sync = sync;
}
protected SynchronizedCollection(final ReferenceCollection<K> c) {
if (c == null)
throw new NullPointerException();
this.collection = c;
this.sync = this;
}
@Override
public boolean add(final K k) {
synchronized (sync) {
return collection.add(k);
}
}
@Override
public boolean contains(final Object k) {
synchronized (sync) {
return collection.contains(k);
}
}
@Override
public boolean remove(final Object k) {
synchronized (sync) {
return collection.remove(k);
}
}
@Override
public int size() {
synchronized (sync) {
return collection.size();
}
}
@Override
public boolean isEmpty() {
synchronized (sync) {
return collection.isEmpty();
}
}
@Override
public Object[] toArray() {
synchronized (sync) {
return collection.toArray();
}
}
@Override
public <T> T[] toArray(final T[] a) {
synchronized (sync) {
return collection.toArray(a);
}
}
@Override
public ObjectIterator<K> iterator() {
return collection.iterator();
}
@Override
public boolean addAll(final Collection<? extends K> c) {
synchronized (sync) {
return collection.addAll(c);
}
}
@Override
public boolean containsAll(final Collection<?> c) {
synchronized (sync) {
return collection.containsAll(c);
}
}
@Override
public boolean removeAll(final Collection<?> c) {
synchronized (sync) {
return collection.removeAll(c);
}
}
@Override
public boolean retainAll(final Collection<?> c) {
synchronized (sync) {
return collection.retainAll(c);
}
}
@Override
public void clear() {
synchronized (sync) {
collection.clear();
}
}
@Override
public String toString() {
synchronized (sync) {
return collection.toString();
}
}
@Override
public int hashCode() {
synchronized (sync) {
return collection.hashCode();
}
}
@Override
public boolean equals(final Object o) {
if (o == this)
return true;
synchronized (sync) {
return collection.equals(o);
}
}
private void writeObject(java.io.ObjectOutputStream s) throws java.io.IOException {
synchronized (sync) {
s.defaultWriteObject();
}
}
}
public static <K> ReferenceCollection<K> synchronize(final ReferenceCollection<K> c) {
return new SynchronizedCollection<>(c);
}
public static <K> ReferenceCollection<K> synchronize(final ReferenceCollection<K> c, final Object sync) {
return new SynchronizedCollection<>(c, sync);
}
public static class UnmodifiableCollection<K> implements ReferenceCollection<K>, java.io.Serializable {
private static final long serialVersionUID = -7046029254386353129L;
protected final ReferenceCollection<K> collection;
protected UnmodifiableCollection(final ReferenceCollection<K> c) {
if (c == null)
throw new NullPointerException();
this.collection = c;
}
@Override
public boolean add(final K k) {
throw new UnsupportedOperationException();
}
@Override
public boolean remove(final Object k) {
throw new UnsupportedOperationException();
}
@Override
public int size() {
return collection.size();
}
@Override
public boolean isEmpty() {
return collection.isEmpty();
}
@Override
public boolean contains(final Object o) {
return collection.contains(o);
}
@Override
public ObjectIterator<K> iterator() {
return ObjectIterators.unmodifiable(collection.iterator());
}
@Override
public void clear() {
throw new UnsupportedOperationException();
}
@Override
public <T> T[] toArray(final T[] a) {
return collection.toArray(a);
}
@Override
public Object[] toArray() {
return collection.toArray();
}
@Override
public boolean containsAll(Collection<?> c) {
return collection.containsAll(c);
}
@Override
public boolean addAll(Collection<? extends K> c) {
throw new UnsupportedOperationException();
}
@Override
public boolean removeAll(Collection<?> c) {
throw new UnsupportedOperationException();
}
@Override
public boolean retainAll(Collection<?> c) {
throw new UnsupportedOperationException();
}
@Override
public String toString() {
return collection.toString();
}
@Override
public int hashCode() {
return collection.hashCode();
}
@Override
public boolean equals(final Object o) {
if (o == this)
return true;
return collection.equals(o);
}
}
public static <K> ReferenceCollection<K> unmodifiable(final ReferenceCollection<K> c) {
return new UnmodifiableCollection<>(c);
}
public static class IterableCollection<K> extends AbstractReferenceCollection<K> implements java.io.Serializable {
private static final long serialVersionUID = -7046029254386353129L;
protected final ObjectIterable<K> iterable;
protected IterableCollection(final ObjectIterable<K> iterable) {
if (iterable == null)
throw new NullPointerException();
this.iterable = iterable;
}
@Override
public int size() {
int c = 0;
final ObjectIterator<K> iterator = iterator();
while (iterator.hasNext()) {
iterator.next();
c++;
}
return c;
}
@Override
public boolean isEmpty() {
return !iterable.iterator().hasNext();
}
@Override
public ObjectIterator<K> iterator() {
return iterable.iterator();
}
}
public static <K> ReferenceCollection<K> asCollection(final ObjectIterable<K> iterable) {
if (iterable instanceof ReferenceCollection)
return (ReferenceCollection<K>) iterable;
return new IterableCollection<>(iterable);
}
}