com.google.common.collect.ImmutableEnumSet Maven / Gradle / Ivy
/*
* Copyright (C) 2009 The Guava Authors
*
* 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.google.common.collect;
import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.J2ktIncompatible;
import com.google.errorprone.annotations.concurrent.LazyInit;
import java.io.InvalidObjectException;
import java.io.ObjectInputStream;
import java.io.Serializable;
import java.util.Collection;
import java.util.EnumSet;
import java.util.Spliterator;
import java.util.function.Consumer;
import javax.annotation.CheckForNull;
/**
* Implementation of {@link ImmutableSet} backed by a non-empty {@link java.util.EnumSet}.
*
* @author Jared Levy
*/
@GwtCompatible(serializable = true, emulated = true)
@SuppressWarnings("serial") // we're overriding default serialization
@ElementTypesAreNonnullByDefault
final class ImmutableEnumSet> extends ImmutableSet {
static > ImmutableSet asImmutable(EnumSet set) {
switch (set.size()) {
case 0:
return ImmutableSet.of();
case 1:
return ImmutableSet.of(Iterables.getOnlyElement(set));
default:
return new ImmutableEnumSet(set);
}
}
/*
* Notes on EnumSet and >:
*
* This class isn't an arbitrary ForwardingImmutableSet because we need to
* know that calling {@code clone()} during deserialization will return an
* object that no one else has a reference to, allowing us to guarantee
* immutability. Hence, we support only {@link EnumSet}.
*/
private final transient EnumSet delegate;
private ImmutableEnumSet(EnumSet delegate) {
this.delegate = delegate;
}
@Override
boolean isPartialView() {
return false;
}
@Override
public UnmodifiableIterator iterator() {
return Iterators.unmodifiableIterator(delegate.iterator());
}
@Override
public Spliterator spliterator() {
return delegate.spliterator();
}
@Override
public void forEach(Consumer super E> action) {
delegate.forEach(action);
}
@Override
public int size() {
return delegate.size();
}
@Override
public boolean contains(@CheckForNull Object object) {
return delegate.contains(object);
}
@Override
public boolean containsAll(Collection> collection) {
if (collection instanceof ImmutableEnumSet>) {
collection = ((ImmutableEnumSet>) collection).delegate;
}
return delegate.containsAll(collection);
}
@Override
public boolean isEmpty() {
return delegate.isEmpty();
}
@Override
public boolean equals(@CheckForNull Object object) {
if (object == this) {
return true;
}
if (object instanceof ImmutableEnumSet) {
object = ((ImmutableEnumSet>) object).delegate;
}
return delegate.equals(object);
}
@Override
boolean isHashCodeFast() {
return true;
}
@LazyInit private transient int hashCode;
@Override
public int hashCode() {
int result = hashCode;
return (result == 0) ? hashCode = delegate.hashCode() : result;
}
@Override
public String toString() {
return delegate.toString();
}
// All callers of the constructor are restricted to >.
@Override
@J2ktIncompatible // serialization
Object writeReplace() {
return new EnumSerializedForm(delegate);
}
@J2ktIncompatible // serialization
private void readObject(ObjectInputStream stream) throws InvalidObjectException {
throw new InvalidObjectException("Use SerializedForm");
}
/*
* This class is used to serialize ImmutableEnumSet instances.
*/
@J2ktIncompatible // serialization
private static class EnumSerializedForm> implements Serializable {
final EnumSet delegate;
EnumSerializedForm(EnumSet delegate) {
this.delegate = delegate;
}
Object readResolve() {
// EJ2 #76: Write readObject() methods defensively.
return new ImmutableEnumSet(delegate.clone());
}
private static final long serialVersionUID = 0;
}
}