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

1 /*
2  * Copyright (C) 2009 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 com.google.common.annotations.GwtCompatible;
20 import com.google.common.annotations.VisibleForTesting;
21 import java.util.Spliterator;
22 import java.util.Spliterators;
23 import org.checkerframework.checker.nullness.qual.Nullable;
24 
25 /**
26  * Implementation of {@link ImmutableList} backed by a simple array.
27  *
28  * @author Kevin Bourrillion
29  */
30 @GwtCompatible(serializable = true, emulated = true)
31 @SuppressWarnings("serial") // uses writeReplace(), not default serialization
32 @ElementTypesAreNonnullByDefault
33 class RegularImmutableList<E> extends ImmutableList<E> {
34   static final ImmutableList<Object> EMPTY = new RegularImmutableList<>(new Object[0]);
35 
36   @VisibleForTesting final transient Object[] array;
37 
38   RegularImmutableList(Object[] array) {
39     this.array = array;
40   }
41 
42   @Override
43   public int size() {
44     return array.length;
45   }
46 
47   @Override
48   boolean isPartialView() {
49     return false;
50   }
51 
52   @Override
53   Object[] internalArray() {
54     return array;
55   }
56 
57   @Override
58   int internalArrayStart() {
59     return 0;
60   }
61 
62   @Override
63   int internalArrayEnd() {
64     return array.length;
65   }
66 
67   @Override
68   int copyIntoArray(@Nullable Object[] dst, int dstOff) {
69     System.arraycopy(array, 0, dst, dstOff, array.length);
70     return dstOff + array.length;
71   }
72 
73   // The fake cast to E is safe because the creation methods only allow E's
74   @Override
75   @SuppressWarnings("unchecked")
76   public E get(int index) {
77     return (E) array[index];
78   }
79 
80   @SuppressWarnings("unchecked")
81   @Override
82   public UnmodifiableListIterator<E> listIterator(int index) {
83     // for performance
84     // The fake cast to E is safe because the creation methods only allow E's
85     return (UnmodifiableListIterator<E>) Iterators.forArray(array, 0, array.length, index);
86   }
87 
88   @Override
89   public Spliterator<E> spliterator() {
90     return Spliterators.spliterator(array, SPLITERATOR_CHARACTERISTICS);
91   }
92 
93   // TODO(lowasser): benchmark optimizations for equals() and see if they're worthwhile
94 }