| /* |
| * 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.errorprone.annotations.concurrent.LazyInit; |
| import java.io.Serializable; |
| import java.util.Collection; |
| import java.util.EnumSet; |
| |
| /** |
| * 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 |
| final class ImmutableEnumSet<E extends Enum<E>> extends ImmutableSet<E> { |
| @SuppressWarnings("rawtypes") // necessary to compile against Java 8 |
| 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 <E extends Enum<E>>: |
| * |
| * 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<E> delegate; |
| |
| private ImmutableEnumSet(EnumSet<E> delegate) { |
| this.delegate = delegate; |
| } |
| |
| @Override |
| boolean isPartialView() { |
| return false; |
| } |
| |
| @Override |
| public UnmodifiableIterator<E> iterator() { |
| return Iterators.unmodifiableIterator(delegate.iterator()); |
| } |
| |
| @Override |
| public int size() { |
| return delegate.size(); |
| } |
| |
| @Override |
| public boolean contains(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(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 <E extends Enum<E>>. |
| @Override |
| Object writeReplace() { |
| return new EnumSerializedForm<E>(delegate); |
| } |
| |
| /* |
| * This class is used to serialize ImmutableEnumSet instances. |
| */ |
| private static class EnumSerializedForm<E extends Enum<E>> implements Serializable { |
| final EnumSet<E> delegate; |
| |
| EnumSerializedForm(EnumSet<E> delegate) { |
| this.delegate = delegate; |
| } |
| |
| Object readResolve() { |
| // EJ2 #76: Write readObject() methods defensively. |
| return new ImmutableEnumSet<E>(delegate.clone()); |
| } |
| |
| private static final long serialVersionUID = 0; |
| } |
| } |