Coverage Summary for Class: ImmutableEnumMap (com.google.common.collect)

1 /*
2  * Copyright (C) 2012 The Guava Authors
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  * http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package com.google.common.collect;
18 
19 import static com.google.common.base.Preconditions.checkArgument;
20 
21 import com.google.common.annotations.GwtCompatible;
22 import com.google.common.collect.ImmutableMap.IteratorBasedImmutableMap;
23 import java.io.Serializable;
24 import java.util.EnumMap;
25 import java.util.Spliterator;
26 import java.util.function.BiConsumer;
27 import org.checkerframework.checker.nullness.qual.Nullable;
28 
29 /**
30  * Implementation of {@link ImmutableMap} backed by a non-empty {@link java.util.EnumMap}.
31  *
32  * @author Louis Wasserman
33  */
34 @GwtCompatible(serializable = true, emulated = true)
35 @SuppressWarnings("serial") // we're overriding default serialization
36 final class ImmutableEnumMap<K extends Enum<K>, V> extends IteratorBasedImmutableMap<K, V> {
37   static <K extends Enum<K>, V> ImmutableMap<K, V> asImmutable(EnumMap<K, V> map) {
38     switch (map.size()) {
39       case 0:
40         return ImmutableMap.of();
41       case 1:
42         Entry<K, V> entry = Iterables.getOnlyElement(map.entrySet());
43         return ImmutableMap.of(entry.getKey(), entry.getValue());
44       default:
45         return new ImmutableEnumMap<>(map);
46     }
47   }
48 
49   private final transient EnumMap<K, V> delegate;
50 
51   private ImmutableEnumMap(EnumMap<K, V> delegate) {
52     this.delegate = delegate;
53     checkArgument(!delegate.isEmpty());
54   }
55 
56   @Override
57   UnmodifiableIterator<K> keyIterator() {
58     return Iterators.unmodifiableIterator(delegate.keySet().iterator());
59   }
60 
61   @Override
62   Spliterator<K> keySpliterator() {
63     return delegate.keySet().spliterator();
64   }
65 
66   @Override
67   public int size() {
68     return delegate.size();
69   }
70 
71   @Override
72   public boolean containsKey(@Nullable Object key) {
73     return delegate.containsKey(key);
74   }
75 
76   @Override
77   public V get(Object key) {
78     return delegate.get(key);
79   }
80 
81   @Override
82   public boolean equals(Object object) {
83     if (object == this) {
84       return true;
85     }
86     if (object instanceof ImmutableEnumMap) {
87       object = ((ImmutableEnumMap<?, ?>) object).delegate;
88     }
89     return delegate.equals(object);
90   }
91 
92   @Override
93   UnmodifiableIterator<Entry<K, V>> entryIterator() {
94     return Maps.unmodifiableEntryIterator(delegate.entrySet().iterator());
95   }
96 
97   @Override
98   Spliterator<Entry<K, V>> entrySpliterator() {
99     return CollectSpliterators.map(delegate.entrySet().spliterator(), Maps::unmodifiableEntry);
100   }
101 
102   @Override
103   public void forEach(BiConsumer<? super K, ? super V> action) {
104     delegate.forEach(action);
105   }
106 
107   @Override
108   boolean isPartialView() {
109     return false;
110   }
111 
112   // All callers of the constructor are restricted to <K extends Enum<K>>.
113   @Override
114   Object writeReplace() {
115     return new EnumSerializedForm<>(delegate);
116   }
117 
118   /*
119    * This class is used to serialize ImmutableEnumMap instances.
120    */
121   private static class EnumSerializedForm<K extends Enum<K>, V> implements Serializable {
122     final EnumMap<K, V> delegate;
123 
124     EnumSerializedForm(EnumMap<K, V> delegate) {
125       this.delegate = delegate;
126     }
127 
128     Object readResolve() {
129       return new ImmutableEnumMap<>(delegate);
130     }
131 
132     private static final long serialVersionUID = 0;
133   }
134 }