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1.1 |
/* |
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jsr166 |
1.33 |
* Copyright (c) 1997, 2016, Oracle and/or its affiliates. All rights reserved. |
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jsr166 |
1.24 |
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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1.1 |
* |
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jsr166 |
1.24 |
* This code is free software; you can redistribute it and/or modify it |
6 |
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* under the terms of the GNU General Public License version 2 only, as |
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jsr166 |
1.33 |
* published by the Free Software Foundation. Oracle designates this |
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jsr166 |
1.24 |
* particular file as subject to the "Classpath" exception as provided |
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jsr166 |
1.33 |
* by Oracle in the LICENSE file that accompanied this code. |
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jsr166 |
1.24 |
* |
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* This code is distributed in the hope that it will be useful, but WITHOUT |
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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* version 2 for more details (a copy is included in the LICENSE file that |
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* accompanied this code). |
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* |
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* You should have received a copy of the GNU General Public License version |
18 |
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* 2 along with this work; if not, write to the Free Software Foundation, |
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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* |
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jsr166 |
1.30 |
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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* or visit www.oracle.com if you need additional information or have any |
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* questions. |
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1.1 |
*/ |
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package java.util; |
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import java.util.function.Consumer; |
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import java.util.function.Predicate; |
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import java.util.function.UnaryOperator; |
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/** |
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* Resizable-array implementation of the {@code List} interface. Implements |
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* all optional list operations, and permits all elements, including |
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* {@code null}. In addition to implementing the {@code List} interface, |
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* this class provides methods to manipulate the size of the array that is |
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* used internally to store the list. (This class is roughly equivalent to |
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* {@code Vector}, except that it is unsynchronized.) |
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* |
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* <p>The {@code size}, {@code isEmpty}, {@code get}, {@code set}, |
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* {@code iterator}, and {@code listIterator} operations run in constant |
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* time. The {@code add} operation runs in <i>amortized constant time</i>, |
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* that is, adding n elements requires O(n) time. All of the other operations |
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* run in linear time (roughly speaking). The constant factor is low compared |
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1.33 |
* to that for the {@code LinkedList} implementation. |
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* |
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1.33 |
* <p>Each {@code ArrayList} instance has a <i>capacity</i>. The capacity is |
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* the size of the array used to store the elements in the list. It is always |
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* at least as large as the list size. As elements are added to an ArrayList, |
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* its capacity grows automatically. The details of the growth policy are not |
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* specified beyond the fact that adding an element has constant amortized |
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* time cost. |
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* |
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* <p>An application can increase the capacity of an {@code ArrayList} instance |
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* before adding a large number of elements using the {@code ensureCapacity} |
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1.1 |
* operation. This may reduce the amount of incremental reallocation. |
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* |
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* <p><strong>Note that this implementation is not synchronized.</strong> |
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* If multiple threads access an {@code ArrayList} instance concurrently, |
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* and at least one of the threads modifies the list structurally, it |
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* <i>must</i> be synchronized externally. (A structural modification is |
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* any operation that adds or deletes one or more elements, or explicitly |
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* resizes the backing array; merely setting the value of an element is not |
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* a structural modification.) This is typically accomplished by |
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* synchronizing on some object that naturally encapsulates the list. |
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* |
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* If no such object exists, the list should be "wrapped" using the |
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* {@link Collections#synchronizedList Collections.synchronizedList} |
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* method. This is best done at creation time, to prevent accidental |
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* unsynchronized access to the list:<pre> |
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* List list = Collections.synchronizedList(new ArrayList(...));</pre> |
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* |
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* <p id="fail-fast"> |
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* The iterators returned by this class's {@link #iterator() iterator} and |
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* {@link #listIterator(int) listIterator} methods are <em>fail-fast</em>: |
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* if the list is structurally modified at any time after the iterator is |
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* created, in any way except through the iterator's own |
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* {@link ListIterator#remove() remove} or |
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* {@link ListIterator#add(Object) add} methods, the iterator will throw a |
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* {@link ConcurrentModificationException}. Thus, in the face of |
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* concurrent modification, the iterator fails quickly and cleanly, rather |
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* than risking arbitrary, non-deterministic behavior at an undetermined |
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* time in the future. |
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1.1 |
* |
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1.25 |
* <p>Note that the fail-fast behavior of an iterator cannot be guaranteed |
86 |
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1.1 |
* as it is, generally speaking, impossible to make any hard guarantees in the |
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* presence of unsynchronized concurrent modification. Fail-fast iterators |
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jsr166 |
1.25 |
* throw {@code ConcurrentModificationException} on a best-effort basis. |
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1.1 |
* Therefore, it would be wrong to write a program that depended on this |
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1.25 |
* exception for its correctness: <i>the fail-fast behavior of iterators |
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* should be used only to detect bugs.</i> |
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1.1 |
* |
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1.25 |
* <p>This class is a member of the |
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1.21 |
* <a href="{@docRoot}/../technotes/guides/collections/index.html"> |
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1.1 |
* Java Collections Framework</a>. |
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* |
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jsr166 |
1.33 |
* @param <E> the type of elements in this list |
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* |
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1.1 |
* @author Josh Bloch |
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* @author Neal Gafter |
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jsr166 |
1.26 |
* @see Collection |
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* @see List |
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* @see LinkedList |
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* @see Vector |
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1.1 |
* @since 1.2 |
106 |
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*/ |
107 |
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public class ArrayList<E> extends AbstractList<E> |
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implements List<E>, RandomAccess, Cloneable, java.io.Serializable |
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{ |
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private static final long serialVersionUID = 8683452581122892189L; |
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/** |
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jsr166 |
1.33 |
* Default initial capacity. |
114 |
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*/ |
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private static final int DEFAULT_CAPACITY = 10; |
116 |
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/** |
118 |
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* Shared empty array instance used for empty instances. |
119 |
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*/ |
120 |
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private static final Object[] EMPTY_ELEMENTDATA = {}; |
121 |
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122 |
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/** |
123 |
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* Shared empty array instance used for default sized empty instances. We |
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* distinguish this from EMPTY_ELEMENTDATA to know how much to inflate when |
125 |
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* first element is added. |
126 |
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*/ |
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private static final Object[] DEFAULTCAPACITY_EMPTY_ELEMENTDATA = {}; |
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129 |
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/** |
130 |
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1.1 |
* The array buffer into which the elements of the ArrayList are stored. |
131 |
jsr166 |
1.33 |
* The capacity of the ArrayList is the length of this array buffer. Any |
132 |
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* empty ArrayList with elementData == DEFAULTCAPACITY_EMPTY_ELEMENTDATA |
133 |
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* will be expanded to DEFAULT_CAPACITY when the first element is added. |
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dl |
1.1 |
*/ |
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jsr166 |
1.33 |
transient Object[] elementData; // non-private to simplify nested class access |
136 |
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1.1 |
|
137 |
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/** |
138 |
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* The size of the ArrayList (the number of elements it contains). |
139 |
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* |
140 |
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* @serial |
141 |
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*/ |
142 |
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private int size; |
143 |
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144 |
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/** |
145 |
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* Constructs an empty list with the specified initial capacity. |
146 |
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* |
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jsr166 |
1.31 |
* @param initialCapacity the initial capacity of the list |
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* @throws IllegalArgumentException if the specified initial capacity |
149 |
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* is negative |
150 |
dl |
1.1 |
*/ |
151 |
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public ArrayList(int initialCapacity) { |
152 |
jsr166 |
1.33 |
if (initialCapacity > 0) { |
153 |
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this.elementData = new Object[initialCapacity]; |
154 |
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} else if (initialCapacity == 0) { |
155 |
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this.elementData = EMPTY_ELEMENTDATA; |
156 |
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} else { |
157 |
dl |
1.1 |
throw new IllegalArgumentException("Illegal Capacity: "+ |
158 |
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initialCapacity); |
159 |
jsr166 |
1.33 |
} |
160 |
dl |
1.1 |
} |
161 |
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162 |
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/** |
163 |
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* Constructs an empty list with an initial capacity of ten. |
164 |
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*/ |
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public ArrayList() { |
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jsr166 |
1.33 |
this.elementData = DEFAULTCAPACITY_EMPTY_ELEMENTDATA; |
167 |
dl |
1.1 |
} |
168 |
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169 |
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/** |
170 |
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* Constructs a list containing the elements of the specified |
171 |
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* collection, in the order they are returned by the collection's |
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jsr166 |
1.17 |
* iterator. |
173 |
dl |
1.1 |
* |
174 |
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* @param c the collection whose elements are to be placed into this list |
175 |
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* @throws NullPointerException if the specified collection is null |
176 |
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*/ |
177 |
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public ArrayList(Collection<? extends E> c) { |
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jsr166 |
1.26 |
elementData = c.toArray(); |
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jsr166 |
1.33 |
if ((size = elementData.length) != 0) { |
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// defend against c.toArray (incorrectly) not returning Object[] |
181 |
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// (see e.g. https://bugs.openjdk.java.net/browse/JDK-6260652) |
182 |
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if (elementData.getClass() != Object[].class) |
183 |
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elementData = Arrays.copyOf(elementData, size, Object[].class); |
184 |
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} else { |
185 |
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// replace with empty array. |
186 |
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this.elementData = EMPTY_ELEMENTDATA; |
187 |
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} |
188 |
dl |
1.2 |
} |
189 |
jsr166 |
1.4 |
|
190 |
dl |
1.1 |
/** |
191 |
jsr166 |
1.33 |
* Trims the capacity of this {@code ArrayList} instance to be the |
192 |
dl |
1.1 |
* list's current size. An application can use this operation to minimize |
193 |
jsr166 |
1.33 |
* the storage of an {@code ArrayList} instance. |
194 |
dl |
1.1 |
*/ |
195 |
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public void trimToSize() { |
196 |
jsr166 |
1.26 |
modCount++; |
197 |
jsr166 |
1.33 |
if (size < elementData.length) { |
198 |
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elementData = (size == 0) |
199 |
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? EMPTY_ELEMENTDATA |
200 |
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: Arrays.copyOf(elementData, size); |
201 |
jsr166 |
1.26 |
} |
202 |
dl |
1.1 |
} |
203 |
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204 |
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/** |
205 |
jsr166 |
1.33 |
* Increases the capacity of this {@code ArrayList} instance, if |
206 |
dl |
1.1 |
* necessary, to ensure that it can hold at least the number of elements |
207 |
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* specified by the minimum capacity argument. |
208 |
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* |
209 |
jsr166 |
1.33 |
* @param minCapacity the desired minimum capacity |
210 |
dl |
1.1 |
*/ |
211 |
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public void ensureCapacity(int minCapacity) { |
212 |
jsr166 |
1.33 |
if (minCapacity > elementData.length |
213 |
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&& !(elementData == DEFAULTCAPACITY_EMPTY_ELEMENTDATA |
214 |
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&& minCapacity <= DEFAULT_CAPACITY)) { |
215 |
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modCount++; |
216 |
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grow(minCapacity); |
217 |
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} |
218 |
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} |
219 |
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|
220 |
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/** |
221 |
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* The maximum size of array to allocate (unless necessary). |
222 |
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* Some VMs reserve some header words in an array. |
223 |
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* Attempts to allocate larger arrays may result in |
224 |
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* OutOfMemoryError: Requested array size exceeds VM limit |
225 |
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*/ |
226 |
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private static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8; |
227 |
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|
228 |
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/** |
229 |
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* Increases the capacity to ensure that it can hold at least the |
230 |
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* number of elements specified by the minimum capacity argument. |
231 |
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* |
232 |
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* @param minCapacity the desired minimum capacity |
233 |
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* @throws OutOfMemoryError if minCapacity is less than zero |
234 |
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*/ |
235 |
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private Object[] grow(int minCapacity) { |
236 |
|
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return elementData = Arrays.copyOf(elementData, |
237 |
|
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newCapacity(minCapacity)); |
238 |
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} |
239 |
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|
240 |
|
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private Object[] grow() { |
241 |
|
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return grow(size + 1); |
242 |
|
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} |
243 |
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|
244 |
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/** |
245 |
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* Returns a capacity at least as large as the given minimum capacity. |
246 |
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* Returns the current capacity increased by 50% if that suffices. |
247 |
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* Will not return a capacity greater than MAX_ARRAY_SIZE unless |
248 |
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* the given minimum capacity is greater than MAX_ARRAY_SIZE. |
249 |
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* |
250 |
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* @param minCapacity the desired minimum capacity |
251 |
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* @throws OutOfMemoryError if minCapacity is less than zero |
252 |
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*/ |
253 |
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private int newCapacity(int minCapacity) { |
254 |
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// overflow-conscious code |
255 |
jsr166 |
1.26 |
int oldCapacity = elementData.length; |
256 |
jsr166 |
1.33 |
int newCapacity = oldCapacity + (oldCapacity >> 1); |
257 |
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if (newCapacity - minCapacity <= 0) { |
258 |
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if (elementData == DEFAULTCAPACITY_EMPTY_ELEMENTDATA) |
259 |
|
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return Math.max(DEFAULT_CAPACITY, minCapacity); |
260 |
|
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if (minCapacity < 0) // overflow |
261 |
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throw new OutOfMemoryError(); |
262 |
|
|
return minCapacity; |
263 |
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|
} |
264 |
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return (newCapacity - MAX_ARRAY_SIZE <= 0) |
265 |
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? newCapacity |
266 |
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|
: hugeCapacity(minCapacity); |
267 |
|
|
} |
268 |
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|
269 |
|
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private static int hugeCapacity(int minCapacity) { |
270 |
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if (minCapacity < 0) // overflow |
271 |
|
|
throw new OutOfMemoryError(); |
272 |
|
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return (minCapacity > MAX_ARRAY_SIZE) |
273 |
|
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? Integer.MAX_VALUE |
274 |
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: MAX_ARRAY_SIZE; |
275 |
dl |
1.1 |
} |
276 |
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|
277 |
|
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/** |
278 |
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* Returns the number of elements in this list. |
279 |
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* |
280 |
|
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* @return the number of elements in this list |
281 |
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*/ |
282 |
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public int size() { |
283 |
jsr166 |
1.26 |
return size; |
284 |
dl |
1.1 |
} |
285 |
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|
286 |
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/** |
287 |
jsr166 |
1.33 |
* Returns {@code true} if this list contains no elements. |
288 |
dl |
1.1 |
* |
289 |
jsr166 |
1.33 |
* @return {@code true} if this list contains no elements |
290 |
dl |
1.1 |
*/ |
291 |
|
|
public boolean isEmpty() { |
292 |
jsr166 |
1.26 |
return size == 0; |
293 |
dl |
1.1 |
} |
294 |
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|
295 |
|
|
/** |
296 |
jsr166 |
1.33 |
* Returns {@code true} if this list contains the specified element. |
297 |
|
|
* More formally, returns {@code true} if and only if this list contains |
298 |
|
|
* at least one element {@code e} such that |
299 |
|
|
* {@code Objects.equals(o, e)}. |
300 |
dl |
1.1 |
* |
301 |
|
|
* @param o element whose presence in this list is to be tested |
302 |
jsr166 |
1.33 |
* @return {@code true} if this list contains the specified element |
303 |
dl |
1.1 |
*/ |
304 |
|
|
public boolean contains(Object o) { |
305 |
jsr166 |
1.26 |
return indexOf(o) >= 0; |
306 |
dl |
1.1 |
} |
307 |
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|
308 |
|
|
/** |
309 |
|
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* Returns the index of the first occurrence of the specified element |
310 |
|
|
* in this list, or -1 if this list does not contain the element. |
311 |
jsr166 |
1.33 |
* More formally, returns the lowest index {@code i} such that |
312 |
|
|
* {@code Objects.equals(o, get(i))}, |
313 |
dl |
1.1 |
* or -1 if there is no such index. |
314 |
|
|
*/ |
315 |
|
|
public int indexOf(Object o) { |
316 |
jsr166 |
1.26 |
if (o == null) { |
317 |
|
|
for (int i = 0; i < size; i++) |
318 |
|
|
if (elementData[i]==null) |
319 |
|
|
return i; |
320 |
|
|
} else { |
321 |
|
|
for (int i = 0; i < size; i++) |
322 |
|
|
if (o.equals(elementData[i])) |
323 |
|
|
return i; |
324 |
|
|
} |
325 |
|
|
return -1; |
326 |
dl |
1.1 |
} |
327 |
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|
|
328 |
|
|
/** |
329 |
|
|
* Returns the index of the last occurrence of the specified element |
330 |
|
|
* in this list, or -1 if this list does not contain the element. |
331 |
jsr166 |
1.33 |
* More formally, returns the highest index {@code i} such that |
332 |
|
|
* {@code Objects.equals(o, get(i))}, |
333 |
dl |
1.1 |
* or -1 if there is no such index. |
334 |
|
|
*/ |
335 |
|
|
public int lastIndexOf(Object o) { |
336 |
jsr166 |
1.26 |
if (o == null) { |
337 |
|
|
for (int i = size-1; i >= 0; i--) |
338 |
|
|
if (elementData[i]==null) |
339 |
|
|
return i; |
340 |
|
|
} else { |
341 |
|
|
for (int i = size-1; i >= 0; i--) |
342 |
|
|
if (o.equals(elementData[i])) |
343 |
|
|
return i; |
344 |
|
|
} |
345 |
|
|
return -1; |
346 |
dl |
1.1 |
} |
347 |
|
|
|
348 |
|
|
/** |
349 |
jsr166 |
1.33 |
* Returns a shallow copy of this {@code ArrayList} instance. (The |
350 |
dl |
1.1 |
* elements themselves are not copied.) |
351 |
|
|
* |
352 |
jsr166 |
1.33 |
* @return a clone of this {@code ArrayList} instance |
353 |
dl |
1.1 |
*/ |
354 |
|
|
public Object clone() { |
355 |
jsr166 |
1.26 |
try { |
356 |
jsr166 |
1.33 |
ArrayList<?> v = (ArrayList<?>) super.clone(); |
357 |
jsr166 |
1.26 |
v.elementData = Arrays.copyOf(elementData, size); |
358 |
|
|
v.modCount = 0; |
359 |
|
|
return v; |
360 |
|
|
} catch (CloneNotSupportedException e) { |
361 |
|
|
// this shouldn't happen, since we are Cloneable |
362 |
jsr166 |
1.33 |
throw new InternalError(e); |
363 |
jsr166 |
1.26 |
} |
364 |
dl |
1.1 |
} |
365 |
|
|
|
366 |
|
|
/** |
367 |
|
|
* Returns an array containing all of the elements in this list |
368 |
|
|
* in proper sequence (from first to last element). |
369 |
|
|
* |
370 |
|
|
* <p>The returned array will be "safe" in that no references to it are |
371 |
|
|
* maintained by this list. (In other words, this method must allocate |
372 |
|
|
* a new array). The caller is thus free to modify the returned array. |
373 |
|
|
* |
374 |
|
|
* <p>This method acts as bridge between array-based and collection-based |
375 |
|
|
* APIs. |
376 |
|
|
* |
377 |
|
|
* @return an array containing all of the elements in this list in |
378 |
|
|
* proper sequence |
379 |
|
|
*/ |
380 |
|
|
public Object[] toArray() { |
381 |
|
|
return Arrays.copyOf(elementData, size); |
382 |
|
|
} |
383 |
|
|
|
384 |
|
|
/** |
385 |
|
|
* Returns an array containing all of the elements in this list in proper |
386 |
|
|
* sequence (from first to last element); the runtime type of the returned |
387 |
|
|
* array is that of the specified array. If the list fits in the |
388 |
|
|
* specified array, it is returned therein. Otherwise, a new array is |
389 |
|
|
* allocated with the runtime type of the specified array and the size of |
390 |
|
|
* this list. |
391 |
|
|
* |
392 |
|
|
* <p>If the list fits in the specified array with room to spare |
393 |
|
|
* (i.e., the array has more elements than the list), the element in |
394 |
|
|
* the array immediately following the end of the collection is set to |
395 |
jsr166 |
1.33 |
* {@code null}. (This is useful in determining the length of the |
396 |
dl |
1.1 |
* list <i>only</i> if the caller knows that the list does not contain |
397 |
|
|
* any null elements.) |
398 |
|
|
* |
399 |
|
|
* @param a the array into which the elements of the list are to |
400 |
|
|
* be stored, if it is big enough; otherwise, a new array of the |
401 |
|
|
* same runtime type is allocated for this purpose. |
402 |
|
|
* @return an array containing the elements of the list |
403 |
|
|
* @throws ArrayStoreException if the runtime type of the specified array |
404 |
|
|
* is not a supertype of the runtime type of every element in |
405 |
|
|
* this list |
406 |
|
|
* @throws NullPointerException if the specified array is null |
407 |
|
|
*/ |
408 |
jsr166 |
1.25 |
@SuppressWarnings("unchecked") |
409 |
dl |
1.1 |
public <T> T[] toArray(T[] a) { |
410 |
|
|
if (a.length < size) |
411 |
|
|
// Make a new array of a's runtime type, but my contents: |
412 |
|
|
return (T[]) Arrays.copyOf(elementData, size, a.getClass()); |
413 |
jsr166 |
1.26 |
System.arraycopy(elementData, 0, a, 0, size); |
414 |
dl |
1.1 |
if (a.length > size) |
415 |
|
|
a[size] = null; |
416 |
|
|
return a; |
417 |
|
|
} |
418 |
|
|
|
419 |
|
|
// Positional Access Operations |
420 |
|
|
|
421 |
jsr166 |
1.25 |
@SuppressWarnings("unchecked") |
422 |
|
|
E elementData(int index) { |
423 |
jsr166 |
1.26 |
return (E) elementData[index]; |
424 |
dl |
1.1 |
} |
425 |
|
|
|
426 |
jsr166 |
1.39 |
@SuppressWarnings("unchecked") |
427 |
|
|
static <E> E elementAt(Object[] es, int index) { |
428 |
|
|
return (E) es[index]; |
429 |
|
|
} |
430 |
|
|
|
431 |
dl |
1.1 |
/** |
432 |
|
|
* Returns the element at the specified position in this list. |
433 |
|
|
* |
434 |
|
|
* @param index index of the element to return |
435 |
|
|
* @return the element at the specified position in this list |
436 |
|
|
* @throws IndexOutOfBoundsException {@inheritDoc} |
437 |
|
|
*/ |
438 |
|
|
public E get(int index) { |
439 |
jsr166 |
1.33 |
Objects.checkIndex(index, size); |
440 |
jsr166 |
1.26 |
return elementData(index); |
441 |
dl |
1.1 |
} |
442 |
|
|
|
443 |
|
|
/** |
444 |
|
|
* Replaces the element at the specified position in this list with |
445 |
|
|
* the specified element. |
446 |
|
|
* |
447 |
|
|
* @param index index of the element to replace |
448 |
|
|
* @param element element to be stored at the specified position |
449 |
|
|
* @return the element previously at the specified position |
450 |
|
|
* @throws IndexOutOfBoundsException {@inheritDoc} |
451 |
|
|
*/ |
452 |
|
|
public E set(int index, E element) { |
453 |
jsr166 |
1.33 |
Objects.checkIndex(index, size); |
454 |
jsr166 |
1.26 |
E oldValue = elementData(index); |
455 |
|
|
elementData[index] = element; |
456 |
|
|
return oldValue; |
457 |
dl |
1.1 |
} |
458 |
|
|
|
459 |
|
|
/** |
460 |
jsr166 |
1.33 |
* This helper method split out from add(E) to keep method |
461 |
|
|
* bytecode size under 35 (the -XX:MaxInlineSize default value), |
462 |
|
|
* which helps when add(E) is called in a C1-compiled loop. |
463 |
|
|
*/ |
464 |
|
|
private void add(E e, Object[] elementData, int s) { |
465 |
|
|
if (s == elementData.length) |
466 |
|
|
elementData = grow(); |
467 |
|
|
elementData[s] = e; |
468 |
|
|
size = s + 1; |
469 |
|
|
} |
470 |
|
|
|
471 |
|
|
/** |
472 |
dl |
1.1 |
* Appends the specified element to the end of this list. |
473 |
|
|
* |
474 |
|
|
* @param e element to be appended to this list |
475 |
jsr166 |
1.33 |
* @return {@code true} (as specified by {@link Collection#add}) |
476 |
dl |
1.1 |
*/ |
477 |
|
|
public boolean add(E e) { |
478 |
jsr166 |
1.33 |
modCount++; |
479 |
|
|
add(e, elementData, size); |
480 |
jsr166 |
1.26 |
return true; |
481 |
dl |
1.1 |
} |
482 |
|
|
|
483 |
|
|
/** |
484 |
|
|
* Inserts the specified element at the specified position in this |
485 |
|
|
* list. Shifts the element currently at that position (if any) and |
486 |
|
|
* any subsequent elements to the right (adds one to their indices). |
487 |
|
|
* |
488 |
|
|
* @param index index at which the specified element is to be inserted |
489 |
|
|
* @param element element to be inserted |
490 |
|
|
* @throws IndexOutOfBoundsException {@inheritDoc} |
491 |
|
|
*/ |
492 |
|
|
public void add(int index, E element) { |
493 |
jsr166 |
1.26 |
rangeCheckForAdd(index); |
494 |
jsr166 |
1.33 |
modCount++; |
495 |
|
|
final int s; |
496 |
|
|
Object[] elementData; |
497 |
|
|
if ((s = size) == (elementData = this.elementData).length) |
498 |
|
|
elementData = grow(); |
499 |
|
|
System.arraycopy(elementData, index, |
500 |
|
|
elementData, index + 1, |
501 |
|
|
s - index); |
502 |
jsr166 |
1.26 |
elementData[index] = element; |
503 |
jsr166 |
1.33 |
size = s + 1; |
504 |
jsr166 |
1.41 |
// checkInvariants(); |
505 |
dl |
1.1 |
} |
506 |
|
|
|
507 |
|
|
/** |
508 |
|
|
* Removes the element at the specified position in this list. |
509 |
|
|
* Shifts any subsequent elements to the left (subtracts one from their |
510 |
|
|
* indices). |
511 |
|
|
* |
512 |
|
|
* @param index the index of the element to be removed |
513 |
|
|
* @return the element that was removed from the list |
514 |
|
|
* @throws IndexOutOfBoundsException {@inheritDoc} |
515 |
|
|
*/ |
516 |
|
|
public E remove(int index) { |
517 |
jsr166 |
1.33 |
Objects.checkIndex(index, size); |
518 |
jsr166 |
1.25 |
|
519 |
jsr166 |
1.26 |
modCount++; |
520 |
|
|
E oldValue = elementData(index); |
521 |
jsr166 |
1.25 |
|
522 |
jsr166 |
1.26 |
int numMoved = size - index - 1; |
523 |
|
|
if (numMoved > 0) |
524 |
|
|
System.arraycopy(elementData, index+1, elementData, index, |
525 |
|
|
numMoved); |
526 |
jsr166 |
1.33 |
elementData[--size] = null; // clear to let GC do its work |
527 |
jsr166 |
1.25 |
|
528 |
jsr166 |
1.41 |
// checkInvariants(); |
529 |
jsr166 |
1.26 |
return oldValue; |
530 |
dl |
1.1 |
} |
531 |
|
|
|
532 |
|
|
/** |
533 |
|
|
* Removes the first occurrence of the specified element from this list, |
534 |
|
|
* if it is present. If the list does not contain the element, it is |
535 |
|
|
* unchanged. More formally, removes the element with the lowest index |
536 |
jsr166 |
1.33 |
* {@code i} such that |
537 |
|
|
* {@code Objects.equals(o, get(i))} |
538 |
|
|
* (if such an element exists). Returns {@code true} if this list |
539 |
dl |
1.1 |
* contained the specified element (or equivalently, if this list |
540 |
|
|
* changed as a result of the call). |
541 |
|
|
* |
542 |
|
|
* @param o element to be removed from this list, if present |
543 |
jsr166 |
1.33 |
* @return {@code true} if this list contained the specified element |
544 |
dl |
1.1 |
*/ |
545 |
|
|
public boolean remove(Object o) { |
546 |
jsr166 |
1.26 |
if (o == null) { |
547 |
|
|
for (int index = 0; index < size; index++) |
548 |
|
|
if (elementData[index] == null) { |
549 |
|
|
fastRemove(index); |
550 |
|
|
return true; |
551 |
|
|
} |
552 |
|
|
} else { |
553 |
dl |
1.1 |
for (int index = 0; index < size; index++) |
554 |
jsr166 |
1.26 |
if (o.equals(elementData[index])) { |
555 |
|
|
fastRemove(index); |
556 |
|
|
return true; |
557 |
|
|
} |
558 |
dl |
1.1 |
} |
559 |
jsr166 |
1.26 |
return false; |
560 |
dl |
1.1 |
} |
561 |
|
|
|
562 |
jsr166 |
1.41 |
/** |
563 |
dl |
1.1 |
* Private remove method that skips bounds checking and does not |
564 |
|
|
* return the value removed. |
565 |
|
|
*/ |
566 |
|
|
private void fastRemove(int index) { |
567 |
|
|
modCount++; |
568 |
|
|
int numMoved = size - index - 1; |
569 |
|
|
if (numMoved > 0) |
570 |
|
|
System.arraycopy(elementData, index+1, elementData, index, |
571 |
|
|
numMoved); |
572 |
jsr166 |
1.33 |
elementData[--size] = null; // clear to let GC do its work |
573 |
dl |
1.1 |
} |
574 |
|
|
|
575 |
|
|
/** |
576 |
|
|
* Removes all of the elements from this list. The list will |
577 |
|
|
* be empty after this call returns. |
578 |
|
|
*/ |
579 |
|
|
public void clear() { |
580 |
jsr166 |
1.26 |
modCount++; |
581 |
jsr166 |
1.47 |
final Object[] es = elementData; |
582 |
|
|
for (int to = size, i = size = 0; i < to; i++) |
583 |
|
|
es[i] = null; |
584 |
dl |
1.1 |
} |
585 |
|
|
|
586 |
|
|
/** |
587 |
|
|
* Appends all of the elements in the specified collection to the end of |
588 |
|
|
* this list, in the order that they are returned by the |
589 |
|
|
* specified collection's Iterator. The behavior of this operation is |
590 |
|
|
* undefined if the specified collection is modified while the operation |
591 |
|
|
* is in progress. (This implies that the behavior of this call is |
592 |
|
|
* undefined if the specified collection is this list, and this |
593 |
|
|
* list is nonempty.) |
594 |
|
|
* |
595 |
|
|
* @param c collection containing elements to be added to this list |
596 |
jsr166 |
1.33 |
* @return {@code true} if this list changed as a result of the call |
597 |
dl |
1.1 |
* @throws NullPointerException if the specified collection is null |
598 |
|
|
*/ |
599 |
|
|
public boolean addAll(Collection<? extends E> c) { |
600 |
jsr166 |
1.26 |
Object[] a = c.toArray(); |
601 |
jsr166 |
1.33 |
modCount++; |
602 |
dl |
1.1 |
int numNew = a.length; |
603 |
jsr166 |
1.33 |
if (numNew == 0) |
604 |
|
|
return false; |
605 |
|
|
Object[] elementData; |
606 |
|
|
final int s; |
607 |
|
|
if (numNew > (elementData = this.elementData).length - (s = size)) |
608 |
|
|
elementData = grow(s + numNew); |
609 |
|
|
System.arraycopy(a, 0, elementData, s, numNew); |
610 |
|
|
size = s + numNew; |
611 |
jsr166 |
1.41 |
// checkInvariants(); |
612 |
jsr166 |
1.33 |
return true; |
613 |
dl |
1.1 |
} |
614 |
|
|
|
615 |
|
|
/** |
616 |
|
|
* Inserts all of the elements in the specified collection into this |
617 |
|
|
* list, starting at the specified position. Shifts the element |
618 |
|
|
* currently at that position (if any) and any subsequent elements to |
619 |
|
|
* the right (increases their indices). The new elements will appear |
620 |
|
|
* in the list in the order that they are returned by the |
621 |
|
|
* specified collection's iterator. |
622 |
|
|
* |
623 |
|
|
* @param index index at which to insert the first element from the |
624 |
|
|
* specified collection |
625 |
|
|
* @param c collection containing elements to be added to this list |
626 |
jsr166 |
1.33 |
* @return {@code true} if this list changed as a result of the call |
627 |
dl |
1.1 |
* @throws IndexOutOfBoundsException {@inheritDoc} |
628 |
|
|
* @throws NullPointerException if the specified collection is null |
629 |
|
|
*/ |
630 |
|
|
public boolean addAll(int index, Collection<? extends E> c) { |
631 |
jsr166 |
1.26 |
rangeCheckForAdd(index); |
632 |
dl |
1.1 |
|
633 |
jsr166 |
1.26 |
Object[] a = c.toArray(); |
634 |
jsr166 |
1.33 |
modCount++; |
635 |
jsr166 |
1.26 |
int numNew = a.length; |
636 |
jsr166 |
1.33 |
if (numNew == 0) |
637 |
|
|
return false; |
638 |
|
|
Object[] elementData; |
639 |
|
|
final int s; |
640 |
|
|
if (numNew > (elementData = this.elementData).length - (s = size)) |
641 |
|
|
elementData = grow(s + numNew); |
642 |
jsr166 |
1.26 |
|
643 |
jsr166 |
1.33 |
int numMoved = s - index; |
644 |
jsr166 |
1.26 |
if (numMoved > 0) |
645 |
jsr166 |
1.33 |
System.arraycopy(elementData, index, |
646 |
|
|
elementData, index + numNew, |
647 |
jsr166 |
1.26 |
numMoved); |
648 |
dl |
1.1 |
System.arraycopy(a, 0, elementData, index, numNew); |
649 |
jsr166 |
1.33 |
size = s + numNew; |
650 |
jsr166 |
1.41 |
// checkInvariants(); |
651 |
jsr166 |
1.33 |
return true; |
652 |
dl |
1.1 |
} |
653 |
|
|
|
654 |
|
|
/** |
655 |
|
|
* Removes from this list all of the elements whose index is between |
656 |
jsr166 |
1.25 |
* {@code fromIndex}, inclusive, and {@code toIndex}, exclusive. |
657 |
dl |
1.1 |
* Shifts any succeeding elements to the left (reduces their index). |
658 |
jsr166 |
1.25 |
* This call shortens the list by {@code (toIndex - fromIndex)} elements. |
659 |
|
|
* (If {@code toIndex==fromIndex}, this operation has no effect.) |
660 |
dl |
1.1 |
* |
661 |
jsr166 |
1.25 |
* @throws IndexOutOfBoundsException if {@code fromIndex} or |
662 |
|
|
* {@code toIndex} is out of range |
663 |
|
|
* ({@code fromIndex < 0 || |
664 |
|
|
* toIndex > size() || |
665 |
|
|
* toIndex < fromIndex}) |
666 |
dl |
1.1 |
*/ |
667 |
|
|
protected void removeRange(int fromIndex, int toIndex) { |
668 |
jsr166 |
1.33 |
if (fromIndex > toIndex) { |
669 |
|
|
throw new IndexOutOfBoundsException( |
670 |
|
|
outOfBoundsMsg(fromIndex, toIndex)); |
671 |
|
|
} |
672 |
jsr166 |
1.26 |
modCount++; |
673 |
jsr166 |
1.47 |
shiftTailOverGap(elementData, fromIndex, toIndex); |
674 |
jsr166 |
1.41 |
// checkInvariants(); |
675 |
jsr166 |
1.25 |
} |
676 |
|
|
|
677 |
jsr166 |
1.47 |
/** Erases the gap from lo to hi, by sliding down following elements. */ |
678 |
|
|
private void shiftTailOverGap(Object[] es, int lo, int hi) { |
679 |
|
|
System.arraycopy(es, hi, es, lo, size - hi); |
680 |
|
|
for (int to = size, i = (size -= hi - lo); i < to; i++) |
681 |
|
|
es[i] = null; |
682 |
|
|
} |
683 |
|
|
|
684 |
jsr166 |
1.25 |
/** |
685 |
|
|
* A version of rangeCheck used by add and addAll. |
686 |
|
|
*/ |
687 |
|
|
private void rangeCheckForAdd(int index) { |
688 |
jsr166 |
1.26 |
if (index > size || index < 0) |
689 |
|
|
throw new IndexOutOfBoundsException(outOfBoundsMsg(index)); |
690 |
jsr166 |
1.25 |
} |
691 |
|
|
|
692 |
|
|
/** |
693 |
|
|
* Constructs an IndexOutOfBoundsException detail message. |
694 |
|
|
* Of the many possible refactorings of the error handling code, |
695 |
|
|
* this "outlining" performs best with both server and client VMs. |
696 |
|
|
*/ |
697 |
|
|
private String outOfBoundsMsg(int index) { |
698 |
jsr166 |
1.26 |
return "Index: "+index+", Size: "+size; |
699 |
jsr166 |
1.25 |
} |
700 |
|
|
|
701 |
|
|
/** |
702 |
jsr166 |
1.33 |
* A version used in checking (fromIndex > toIndex) condition |
703 |
|
|
*/ |
704 |
|
|
private static String outOfBoundsMsg(int fromIndex, int toIndex) { |
705 |
|
|
return "From Index: " + fromIndex + " > To Index: " + toIndex; |
706 |
|
|
} |
707 |
|
|
|
708 |
|
|
/** |
709 |
jsr166 |
1.25 |
* Removes from this list all of its elements that are contained in the |
710 |
|
|
* specified collection. |
711 |
|
|
* |
712 |
|
|
* @param c collection containing elements to be removed from this list |
713 |
|
|
* @return {@code true} if this list changed as a result of the call |
714 |
|
|
* @throws ClassCastException if the class of an element of this list |
715 |
jsr166 |
1.33 |
* is incompatible with the specified collection |
716 |
|
|
* (<a href="Collection.html#optional-restrictions">optional</a>) |
717 |
jsr166 |
1.25 |
* @throws NullPointerException if this list contains a null element and the |
718 |
jsr166 |
1.33 |
* specified collection does not permit null elements |
719 |
|
|
* (<a href="Collection.html#optional-restrictions">optional</a>), |
720 |
jsr166 |
1.25 |
* or if the specified collection is null |
721 |
|
|
* @see Collection#contains(Object) |
722 |
|
|
*/ |
723 |
|
|
public boolean removeAll(Collection<?> c) { |
724 |
jsr166 |
1.40 |
return batchRemove(c, false, 0, size); |
725 |
jsr166 |
1.25 |
} |
726 |
|
|
|
727 |
|
|
/** |
728 |
|
|
* Retains only the elements in this list that are contained in the |
729 |
|
|
* specified collection. In other words, removes from this list all |
730 |
|
|
* of its elements that are not contained in the specified collection. |
731 |
|
|
* |
732 |
|
|
* @param c collection containing elements to be retained in this list |
733 |
|
|
* @return {@code true} if this list changed as a result of the call |
734 |
|
|
* @throws ClassCastException if the class of an element of this list |
735 |
jsr166 |
1.33 |
* is incompatible with the specified collection |
736 |
|
|
* (<a href="Collection.html#optional-restrictions">optional</a>) |
737 |
jsr166 |
1.25 |
* @throws NullPointerException if this list contains a null element and the |
738 |
jsr166 |
1.33 |
* specified collection does not permit null elements |
739 |
|
|
* (<a href="Collection.html#optional-restrictions">optional</a>), |
740 |
jsr166 |
1.25 |
* or if the specified collection is null |
741 |
|
|
* @see Collection#contains(Object) |
742 |
|
|
*/ |
743 |
|
|
public boolean retainAll(Collection<?> c) { |
744 |
jsr166 |
1.40 |
return batchRemove(c, true, 0, size); |
745 |
jsr166 |
1.25 |
} |
746 |
|
|
|
747 |
jsr166 |
1.40 |
boolean batchRemove(Collection<?> c, boolean complement, |
748 |
|
|
final int from, final int end) { |
749 |
jsr166 |
1.37 |
Objects.requireNonNull(c); |
750 |
|
|
final Object[] es = elementData; |
751 |
|
|
final boolean modified; |
752 |
|
|
int r; |
753 |
|
|
// Optimize for initial run of survivors |
754 |
jsr166 |
1.40 |
for (r = from; r < end && c.contains(es[r]) == complement; r++) |
755 |
jsr166 |
1.38 |
; |
756 |
jsr166 |
1.39 |
if (modified = (r < end)) { |
757 |
jsr166 |
1.37 |
int w = r++; |
758 |
|
|
try { |
759 |
jsr166 |
1.39 |
for (Object e; r < end; r++) |
760 |
jsr166 |
1.37 |
if (c.contains(e = es[r]) == complement) |
761 |
|
|
es[w++] = e; |
762 |
|
|
} catch (Throwable ex) { |
763 |
|
|
// Preserve behavioral compatibility with AbstractCollection, |
764 |
|
|
// even if c.contains() throws. |
765 |
jsr166 |
1.39 |
System.arraycopy(es, r, es, w, end - r); |
766 |
|
|
w += end - r; |
767 |
jsr166 |
1.37 |
throw ex; |
768 |
|
|
} finally { |
769 |
jsr166 |
1.47 |
modCount += end - w; |
770 |
|
|
shiftTailOverGap(es, w, end); |
771 |
jsr166 |
1.26 |
} |
772 |
|
|
} |
773 |
jsr166 |
1.41 |
// checkInvariants(); |
774 |
jsr166 |
1.26 |
return modified; |
775 |
jsr166 |
1.25 |
} |
776 |
|
|
|
777 |
|
|
/** |
778 |
jsr166 |
1.46 |
* Saves the state of the {@code ArrayList} instance to a stream |
779 |
|
|
* (that is, serializes it). |
780 |
dl |
1.1 |
* |
781 |
jsr166 |
1.46 |
* @param s the stream |
782 |
|
|
* @throws java.io.IOException if an I/O error occurs |
783 |
jsr166 |
1.33 |
* @serialData The length of the array backing the {@code ArrayList} |
784 |
dl |
1.1 |
* instance is emitted (int), followed by all of its elements |
785 |
jsr166 |
1.33 |
* (each an {@code Object}) in the proper order. |
786 |
dl |
1.1 |
*/ |
787 |
|
|
private void writeObject(java.io.ObjectOutputStream s) |
788 |
jsr166 |
1.46 |
throws java.io.IOException { |
789 |
jsr166 |
1.26 |
// Write out element count, and any hidden stuff |
790 |
|
|
int expectedModCount = modCount; |
791 |
|
|
s.defaultWriteObject(); |
792 |
dl |
1.1 |
|
793 |
jsr166 |
1.33 |
// Write out size as capacity for behavioural compatibility with clone() |
794 |
|
|
s.writeInt(size); |
795 |
dl |
1.1 |
|
796 |
jsr166 |
1.26 |
// Write out all elements in the proper order. |
797 |
jsr166 |
1.33 |
for (int i=0; i<size; i++) { |
798 |
dl |
1.1 |
s.writeObject(elementData[i]); |
799 |
jsr166 |
1.33 |
} |
800 |
dl |
1.1 |
|
801 |
jsr166 |
1.26 |
if (modCount != expectedModCount) { |
802 |
dl |
1.1 |
throw new ConcurrentModificationException(); |
803 |
|
|
} |
804 |
|
|
} |
805 |
|
|
|
806 |
|
|
/** |
807 |
jsr166 |
1.46 |
* Reconstitutes the {@code ArrayList} instance from a stream (that is, |
808 |
|
|
* deserializes it). |
809 |
|
|
* @param s the stream |
810 |
|
|
* @throws ClassNotFoundException if the class of a serialized object |
811 |
|
|
* could not be found |
812 |
|
|
* @throws java.io.IOException if an I/O error occurs |
813 |
dl |
1.1 |
*/ |
814 |
|
|
private void readObject(java.io.ObjectInputStream s) |
815 |
|
|
throws java.io.IOException, ClassNotFoundException { |
816 |
jsr166 |
1.33 |
|
817 |
jsr166 |
1.26 |
// Read in size, and any hidden stuff |
818 |
|
|
s.defaultReadObject(); |
819 |
dl |
1.1 |
|
820 |
jsr166 |
1.33 |
// Read in capacity |
821 |
|
|
s.readInt(); // ignored |
822 |
|
|
|
823 |
|
|
if (size > 0) { |
824 |
|
|
// like clone(), allocate array based upon size not capacity |
825 |
|
|
Object[] elements = new Object[size]; |
826 |
|
|
|
827 |
|
|
// Read in all elements in the proper order. |
828 |
|
|
for (int i = 0; i < size; i++) { |
829 |
|
|
elements[i] = s.readObject(); |
830 |
|
|
} |
831 |
|
|
|
832 |
|
|
elementData = elements; |
833 |
|
|
} else if (size == 0) { |
834 |
|
|
elementData = EMPTY_ELEMENTDATA; |
835 |
|
|
} else { |
836 |
|
|
throw new java.io.InvalidObjectException("Invalid size: " + size); |
837 |
|
|
} |
838 |
dl |
1.1 |
} |
839 |
jsr166 |
1.25 |
|
840 |
|
|
/** |
841 |
|
|
* Returns a list iterator over the elements in this list (in proper |
842 |
|
|
* sequence), starting at the specified position in the list. |
843 |
|
|
* The specified index indicates the first element that would be |
844 |
|
|
* returned by an initial call to {@link ListIterator#next next}. |
845 |
|
|
* An initial call to {@link ListIterator#previous previous} would |
846 |
|
|
* return the element with the specified index minus one. |
847 |
|
|
* |
848 |
|
|
* <p>The returned list iterator is <a href="#fail-fast"><i>fail-fast</i></a>. |
849 |
|
|
* |
850 |
|
|
* @throws IndexOutOfBoundsException {@inheritDoc} |
851 |
|
|
*/ |
852 |
|
|
public ListIterator<E> listIterator(int index) { |
853 |
jsr166 |
1.33 |
rangeCheckForAdd(index); |
854 |
jsr166 |
1.26 |
return new ListItr(index); |
855 |
jsr166 |
1.25 |
} |
856 |
|
|
|
857 |
|
|
/** |
858 |
|
|
* Returns a list iterator over the elements in this list (in proper |
859 |
|
|
* sequence). |
860 |
|
|
* |
861 |
|
|
* <p>The returned list iterator is <a href="#fail-fast"><i>fail-fast</i></a>. |
862 |
|
|
* |
863 |
|
|
* @see #listIterator(int) |
864 |
|
|
*/ |
865 |
|
|
public ListIterator<E> listIterator() { |
866 |
jsr166 |
1.26 |
return new ListItr(0); |
867 |
jsr166 |
1.25 |
} |
868 |
|
|
|
869 |
|
|
/** |
870 |
|
|
* Returns an iterator over the elements in this list in proper sequence. |
871 |
|
|
* |
872 |
|
|
* <p>The returned iterator is <a href="#fail-fast"><i>fail-fast</i></a>. |
873 |
|
|
* |
874 |
|
|
* @return an iterator over the elements in this list in proper sequence |
875 |
|
|
*/ |
876 |
|
|
public Iterator<E> iterator() { |
877 |
jsr166 |
1.26 |
return new Itr(); |
878 |
jsr166 |
1.25 |
} |
879 |
|
|
|
880 |
|
|
/** |
881 |
|
|
* An optimized version of AbstractList.Itr |
882 |
|
|
*/ |
883 |
|
|
private class Itr implements Iterator<E> { |
884 |
jsr166 |
1.26 |
int cursor; // index of next element to return |
885 |
|
|
int lastRet = -1; // index of last element returned; -1 if no such |
886 |
|
|
int expectedModCount = modCount; |
887 |
jsr166 |
1.25 |
|
888 |
jsr166 |
1.33 |
// prevent creating a synthetic constructor |
889 |
|
|
Itr() {} |
890 |
|
|
|
891 |
jsr166 |
1.26 |
public boolean hasNext() { |
892 |
jsr166 |
1.25 |
return cursor != size; |
893 |
jsr166 |
1.26 |
} |
894 |
|
|
|
895 |
|
|
@SuppressWarnings("unchecked") |
896 |
|
|
public E next() { |
897 |
|
|
checkForComodification(); |
898 |
|
|
int i = cursor; |
899 |
|
|
if (i >= size) |
900 |
|
|
throw new NoSuchElementException(); |
901 |
|
|
Object[] elementData = ArrayList.this.elementData; |
902 |
|
|
if (i >= elementData.length) |
903 |
|
|
throw new ConcurrentModificationException(); |
904 |
|
|
cursor = i + 1; |
905 |
|
|
return (E) elementData[lastRet = i]; |
906 |
|
|
} |
907 |
jsr166 |
1.25 |
|
908 |
jsr166 |
1.26 |
public void remove() { |
909 |
|
|
if (lastRet < 0) |
910 |
|
|
throw new IllegalStateException(); |
911 |
jsr166 |
1.25 |
checkForComodification(); |
912 |
jsr166 |
1.26 |
|
913 |
|
|
try { |
914 |
|
|
ArrayList.this.remove(lastRet); |
915 |
|
|
cursor = lastRet; |
916 |
|
|
lastRet = -1; |
917 |
|
|
expectedModCount = modCount; |
918 |
|
|
} catch (IndexOutOfBoundsException ex) { |
919 |
|
|
throw new ConcurrentModificationException(); |
920 |
|
|
} |
921 |
|
|
} |
922 |
|
|
|
923 |
jsr166 |
1.33 |
@Override |
924 |
jsr166 |
1.44 |
public void forEachRemaining(Consumer<? super E> action) { |
925 |
|
|
Objects.requireNonNull(action); |
926 |
jsr166 |
1.33 |
final int size = ArrayList.this.size; |
927 |
|
|
int i = cursor; |
928 |
jsr166 |
1.44 |
if (i < size) { |
929 |
|
|
final Object[] es = elementData; |
930 |
|
|
if (i >= es.length) |
931 |
|
|
throw new ConcurrentModificationException(); |
932 |
|
|
for (; i < size && modCount == expectedModCount; i++) |
933 |
|
|
action.accept(elementAt(es, i)); |
934 |
|
|
// update once at end to reduce heap write traffic |
935 |
|
|
cursor = i; |
936 |
|
|
lastRet = i - 1; |
937 |
|
|
checkForComodification(); |
938 |
jsr166 |
1.33 |
} |
939 |
|
|
} |
940 |
|
|
|
941 |
jsr166 |
1.26 |
final void checkForComodification() { |
942 |
|
|
if (modCount != expectedModCount) |
943 |
|
|
throw new ConcurrentModificationException(); |
944 |
|
|
} |
945 |
jsr166 |
1.25 |
} |
946 |
|
|
|
947 |
|
|
/** |
948 |
|
|
* An optimized version of AbstractList.ListItr |
949 |
|
|
*/ |
950 |
|
|
private class ListItr extends Itr implements ListIterator<E> { |
951 |
jsr166 |
1.26 |
ListItr(int index) { |
952 |
|
|
super(); |
953 |
|
|
cursor = index; |
954 |
|
|
} |
955 |
|
|
|
956 |
|
|
public boolean hasPrevious() { |
957 |
|
|
return cursor != 0; |
958 |
|
|
} |
959 |
jsr166 |
1.25 |
|
960 |
jsr166 |
1.26 |
public int nextIndex() { |
961 |
|
|
return cursor; |
962 |
|
|
} |
963 |
|
|
|
964 |
|
|
public int previousIndex() { |
965 |
|
|
return cursor - 1; |
966 |
|
|
} |
967 |
|
|
|
968 |
|
|
@SuppressWarnings("unchecked") |
969 |
jsr166 |
1.25 |
public E previous() { |
970 |
jsr166 |
1.26 |
checkForComodification(); |
971 |
|
|
int i = cursor - 1; |
972 |
|
|
if (i < 0) |
973 |
|
|
throw new NoSuchElementException(); |
974 |
|
|
Object[] elementData = ArrayList.this.elementData; |
975 |
|
|
if (i >= elementData.length) |
976 |
|
|
throw new ConcurrentModificationException(); |
977 |
|
|
cursor = i; |
978 |
|
|
return (E) elementData[lastRet = i]; |
979 |
|
|
} |
980 |
|
|
|
981 |
|
|
public void set(E e) { |
982 |
|
|
if (lastRet < 0) |
983 |
|
|
throw new IllegalStateException(); |
984 |
|
|
checkForComodification(); |
985 |
|
|
|
986 |
|
|
try { |
987 |
|
|
ArrayList.this.set(lastRet, e); |
988 |
|
|
} catch (IndexOutOfBoundsException ex) { |
989 |
|
|
throw new ConcurrentModificationException(); |
990 |
|
|
} |
991 |
|
|
} |
992 |
|
|
|
993 |
|
|
public void add(E e) { |
994 |
|
|
checkForComodification(); |
995 |
|
|
|
996 |
|
|
try { |
997 |
|
|
int i = cursor; |
998 |
|
|
ArrayList.this.add(i, e); |
999 |
|
|
cursor = i + 1; |
1000 |
|
|
lastRet = -1; |
1001 |
|
|
expectedModCount = modCount; |
1002 |
|
|
} catch (IndexOutOfBoundsException ex) { |
1003 |
|
|
throw new ConcurrentModificationException(); |
1004 |
|
|
} |
1005 |
|
|
} |
1006 |
jsr166 |
1.25 |
} |
1007 |
|
|
|
1008 |
|
|
/** |
1009 |
|
|
* Returns a view of the portion of this list between the specified |
1010 |
|
|
* {@code fromIndex}, inclusive, and {@code toIndex}, exclusive. (If |
1011 |
|
|
* {@code fromIndex} and {@code toIndex} are equal, the returned list is |
1012 |
|
|
* empty.) The returned list is backed by this list, so non-structural |
1013 |
|
|
* changes in the returned list are reflected in this list, and vice-versa. |
1014 |
|
|
* The returned list supports all of the optional list operations. |
1015 |
|
|
* |
1016 |
|
|
* <p>This method eliminates the need for explicit range operations (of |
1017 |
|
|
* the sort that commonly exist for arrays). Any operation that expects |
1018 |
|
|
* a list can be used as a range operation by passing a subList view |
1019 |
|
|
* instead of a whole list. For example, the following idiom |
1020 |
|
|
* removes a range of elements from a list: |
1021 |
|
|
* <pre> |
1022 |
|
|
* list.subList(from, to).clear(); |
1023 |
|
|
* </pre> |
1024 |
|
|
* Similar idioms may be constructed for {@link #indexOf(Object)} and |
1025 |
|
|
* {@link #lastIndexOf(Object)}, and all of the algorithms in the |
1026 |
|
|
* {@link Collections} class can be applied to a subList. |
1027 |
|
|
* |
1028 |
|
|
* <p>The semantics of the list returned by this method become undefined if |
1029 |
|
|
* the backing list (i.e., this list) is <i>structurally modified</i> in |
1030 |
|
|
* any way other than via the returned list. (Structural modifications are |
1031 |
|
|
* those that change the size of this list, or otherwise perturb it in such |
1032 |
|
|
* a fashion that iterations in progress may yield incorrect results.) |
1033 |
|
|
* |
1034 |
|
|
* @throws IndexOutOfBoundsException {@inheritDoc} |
1035 |
|
|
* @throws IllegalArgumentException {@inheritDoc} |
1036 |
|
|
*/ |
1037 |
|
|
public List<E> subList(int fromIndex, int toIndex) { |
1038 |
jsr166 |
1.26 |
subListRangeCheck(fromIndex, toIndex, size); |
1039 |
jsr166 |
1.33 |
return new SubList<>(this, fromIndex, toIndex); |
1040 |
jsr166 |
1.25 |
} |
1041 |
|
|
|
1042 |
jsr166 |
1.33 |
private static class SubList<E> extends AbstractList<E> implements RandomAccess { |
1043 |
|
|
private final ArrayList<E> root; |
1044 |
|
|
private final SubList<E> parent; |
1045 |
jsr166 |
1.26 |
private final int offset; |
1046 |
jsr166 |
1.33 |
private int size; |
1047 |
jsr166 |
1.26 |
|
1048 |
jsr166 |
1.33 |
/** |
1049 |
|
|
* Constructs a sublist of an arbitrary ArrayList. |
1050 |
|
|
*/ |
1051 |
|
|
public SubList(ArrayList<E> root, int fromIndex, int toIndex) { |
1052 |
|
|
this.root = root; |
1053 |
|
|
this.parent = null; |
1054 |
|
|
this.offset = fromIndex; |
1055 |
|
|
this.size = toIndex - fromIndex; |
1056 |
|
|
this.modCount = root.modCount; |
1057 |
|
|
} |
1058 |
|
|
|
1059 |
|
|
/** |
1060 |
|
|
* Constructs a sublist of another SubList. |
1061 |
|
|
*/ |
1062 |
|
|
private SubList(SubList<E> parent, int fromIndex, int toIndex) { |
1063 |
|
|
this.root = parent.root; |
1064 |
jsr166 |
1.26 |
this.parent = parent; |
1065 |
jsr166 |
1.33 |
this.offset = parent.offset + fromIndex; |
1066 |
jsr166 |
1.26 |
this.size = toIndex - fromIndex; |
1067 |
jsr166 |
1.33 |
this.modCount = root.modCount; |
1068 |
jsr166 |
1.26 |
} |
1069 |
|
|
|
1070 |
jsr166 |
1.33 |
public E set(int index, E element) { |
1071 |
|
|
Objects.checkIndex(index, size); |
1072 |
jsr166 |
1.26 |
checkForComodification(); |
1073 |
jsr166 |
1.33 |
E oldValue = root.elementData(offset + index); |
1074 |
|
|
root.elementData[offset + index] = element; |
1075 |
jsr166 |
1.26 |
return oldValue; |
1076 |
|
|
} |
1077 |
|
|
|
1078 |
|
|
public E get(int index) { |
1079 |
jsr166 |
1.33 |
Objects.checkIndex(index, size); |
1080 |
jsr166 |
1.26 |
checkForComodification(); |
1081 |
jsr166 |
1.33 |
return root.elementData(offset + index); |
1082 |
jsr166 |
1.26 |
} |
1083 |
|
|
|
1084 |
|
|
public int size() { |
1085 |
|
|
checkForComodification(); |
1086 |
jsr166 |
1.33 |
return size; |
1087 |
jsr166 |
1.26 |
} |
1088 |
|
|
|
1089 |
jsr166 |
1.33 |
public void add(int index, E element) { |
1090 |
jsr166 |
1.26 |
rangeCheckForAdd(index); |
1091 |
|
|
checkForComodification(); |
1092 |
jsr166 |
1.33 |
root.add(offset + index, element); |
1093 |
|
|
updateSizeAndModCount(1); |
1094 |
jsr166 |
1.26 |
} |
1095 |
|
|
|
1096 |
|
|
public E remove(int index) { |
1097 |
jsr166 |
1.33 |
Objects.checkIndex(index, size); |
1098 |
jsr166 |
1.26 |
checkForComodification(); |
1099 |
jsr166 |
1.33 |
E result = root.remove(offset + index); |
1100 |
|
|
updateSizeAndModCount(-1); |
1101 |
jsr166 |
1.26 |
return result; |
1102 |
|
|
} |
1103 |
|
|
|
1104 |
|
|
protected void removeRange(int fromIndex, int toIndex) { |
1105 |
|
|
checkForComodification(); |
1106 |
jsr166 |
1.33 |
root.removeRange(offset + fromIndex, offset + toIndex); |
1107 |
|
|
updateSizeAndModCount(fromIndex - toIndex); |
1108 |
jsr166 |
1.26 |
} |
1109 |
|
|
|
1110 |
|
|
public boolean addAll(Collection<? extends E> c) { |
1111 |
|
|
return addAll(this.size, c); |
1112 |
|
|
} |
1113 |
|
|
|
1114 |
|
|
public boolean addAll(int index, Collection<? extends E> c) { |
1115 |
|
|
rangeCheckForAdd(index); |
1116 |
|
|
int cSize = c.size(); |
1117 |
|
|
if (cSize==0) |
1118 |
|
|
return false; |
1119 |
|
|
checkForComodification(); |
1120 |
jsr166 |
1.33 |
root.addAll(offset + index, c); |
1121 |
|
|
updateSizeAndModCount(cSize); |
1122 |
jsr166 |
1.26 |
return true; |
1123 |
|
|
} |
1124 |
|
|
|
1125 |
jsr166 |
1.40 |
public boolean removeAll(Collection<?> c) { |
1126 |
|
|
return batchRemove(c, false); |
1127 |
|
|
} |
1128 |
jsr166 |
1.41 |
|
1129 |
jsr166 |
1.40 |
public boolean retainAll(Collection<?> c) { |
1130 |
|
|
return batchRemove(c, true); |
1131 |
|
|
} |
1132 |
|
|
|
1133 |
|
|
private boolean batchRemove(Collection<?> c, boolean complement) { |
1134 |
|
|
checkForComodification(); |
1135 |
|
|
int oldSize = root.size; |
1136 |
|
|
boolean modified = |
1137 |
|
|
root.batchRemove(c, complement, offset, offset + size); |
1138 |
|
|
if (modified) |
1139 |
|
|
updateSizeAndModCount(root.size - oldSize); |
1140 |
|
|
return modified; |
1141 |
|
|
} |
1142 |
|
|
|
1143 |
|
|
public boolean removeIf(Predicate<? super E> filter) { |
1144 |
|
|
checkForComodification(); |
1145 |
|
|
int oldSize = root.size; |
1146 |
|
|
boolean modified = root.removeIf(filter, offset, offset + size); |
1147 |
|
|
if (modified) |
1148 |
|
|
updateSizeAndModCount(root.size - oldSize); |
1149 |
|
|
return modified; |
1150 |
|
|
} |
1151 |
|
|
|
1152 |
jsr166 |
1.26 |
public Iterator<E> iterator() { |
1153 |
|
|
return listIterator(); |
1154 |
|
|
} |
1155 |
|
|
|
1156 |
jsr166 |
1.33 |
public ListIterator<E> listIterator(int index) { |
1157 |
jsr166 |
1.26 |
checkForComodification(); |
1158 |
|
|
rangeCheckForAdd(index); |
1159 |
|
|
|
1160 |
|
|
return new ListIterator<E>() { |
1161 |
|
|
int cursor = index; |
1162 |
|
|
int lastRet = -1; |
1163 |
jsr166 |
1.33 |
int expectedModCount = root.modCount; |
1164 |
jsr166 |
1.26 |
|
1165 |
|
|
public boolean hasNext() { |
1166 |
|
|
return cursor != SubList.this.size; |
1167 |
|
|
} |
1168 |
|
|
|
1169 |
|
|
@SuppressWarnings("unchecked") |
1170 |
|
|
public E next() { |
1171 |
|
|
checkForComodification(); |
1172 |
|
|
int i = cursor; |
1173 |
|
|
if (i >= SubList.this.size) |
1174 |
|
|
throw new NoSuchElementException(); |
1175 |
jsr166 |
1.33 |
Object[] elementData = root.elementData; |
1176 |
jsr166 |
1.26 |
if (offset + i >= elementData.length) |
1177 |
|
|
throw new ConcurrentModificationException(); |
1178 |
|
|
cursor = i + 1; |
1179 |
|
|
return (E) elementData[offset + (lastRet = i)]; |
1180 |
|
|
} |
1181 |
|
|
|
1182 |
|
|
public boolean hasPrevious() { |
1183 |
|
|
return cursor != 0; |
1184 |
|
|
} |
1185 |
|
|
|
1186 |
|
|
@SuppressWarnings("unchecked") |
1187 |
|
|
public E previous() { |
1188 |
|
|
checkForComodification(); |
1189 |
|
|
int i = cursor - 1; |
1190 |
|
|
if (i < 0) |
1191 |
|
|
throw new NoSuchElementException(); |
1192 |
jsr166 |
1.33 |
Object[] elementData = root.elementData; |
1193 |
jsr166 |
1.26 |
if (offset + i >= elementData.length) |
1194 |
|
|
throw new ConcurrentModificationException(); |
1195 |
|
|
cursor = i; |
1196 |
|
|
return (E) elementData[offset + (lastRet = i)]; |
1197 |
|
|
} |
1198 |
|
|
|
1199 |
jsr166 |
1.44 |
public void forEachRemaining(Consumer<? super E> action) { |
1200 |
|
|
Objects.requireNonNull(action); |
1201 |
jsr166 |
1.33 |
final int size = SubList.this.size; |
1202 |
|
|
int i = cursor; |
1203 |
jsr166 |
1.44 |
if (i < size) { |
1204 |
|
|
final Object[] es = root.elementData; |
1205 |
|
|
if (offset + i >= es.length) |
1206 |
|
|
throw new ConcurrentModificationException(); |
1207 |
|
|
for (; i < size && modCount == expectedModCount; i++) |
1208 |
|
|
action.accept(elementAt(es, offset + i)); |
1209 |
|
|
// update once at end to reduce heap write traffic |
1210 |
|
|
cursor = i; |
1211 |
|
|
lastRet = i - 1; |
1212 |
|
|
checkForComodification(); |
1213 |
jsr166 |
1.33 |
} |
1214 |
|
|
} |
1215 |
|
|
|
1216 |
jsr166 |
1.26 |
public int nextIndex() { |
1217 |
|
|
return cursor; |
1218 |
|
|
} |
1219 |
|
|
|
1220 |
|
|
public int previousIndex() { |
1221 |
|
|
return cursor - 1; |
1222 |
|
|
} |
1223 |
|
|
|
1224 |
|
|
public void remove() { |
1225 |
|
|
if (lastRet < 0) |
1226 |
|
|
throw new IllegalStateException(); |
1227 |
|
|
checkForComodification(); |
1228 |
|
|
|
1229 |
|
|
try { |
1230 |
|
|
SubList.this.remove(lastRet); |
1231 |
|
|
cursor = lastRet; |
1232 |
|
|
lastRet = -1; |
1233 |
jsr166 |
1.33 |
expectedModCount = root.modCount; |
1234 |
jsr166 |
1.26 |
} catch (IndexOutOfBoundsException ex) { |
1235 |
|
|
throw new ConcurrentModificationException(); |
1236 |
|
|
} |
1237 |
|
|
} |
1238 |
|
|
|
1239 |
|
|
public void set(E e) { |
1240 |
|
|
if (lastRet < 0) |
1241 |
|
|
throw new IllegalStateException(); |
1242 |
|
|
checkForComodification(); |
1243 |
|
|
|
1244 |
|
|
try { |
1245 |
jsr166 |
1.33 |
root.set(offset + lastRet, e); |
1246 |
jsr166 |
1.26 |
} catch (IndexOutOfBoundsException ex) { |
1247 |
|
|
throw new ConcurrentModificationException(); |
1248 |
|
|
} |
1249 |
|
|
} |
1250 |
|
|
|
1251 |
|
|
public void add(E e) { |
1252 |
|
|
checkForComodification(); |
1253 |
|
|
|
1254 |
|
|
try { |
1255 |
|
|
int i = cursor; |
1256 |
|
|
SubList.this.add(i, e); |
1257 |
|
|
cursor = i + 1; |
1258 |
|
|
lastRet = -1; |
1259 |
jsr166 |
1.33 |
expectedModCount = root.modCount; |
1260 |
jsr166 |
1.26 |
} catch (IndexOutOfBoundsException ex) { |
1261 |
|
|
throw new ConcurrentModificationException(); |
1262 |
|
|
} |
1263 |
|
|
} |
1264 |
|
|
|
1265 |
|
|
final void checkForComodification() { |
1266 |
jsr166 |
1.33 |
if (root.modCount != expectedModCount) |
1267 |
jsr166 |
1.26 |
throw new ConcurrentModificationException(); |
1268 |
|
|
} |
1269 |
|
|
}; |
1270 |
|
|
} |
1271 |
|
|
|
1272 |
|
|
public List<E> subList(int fromIndex, int toIndex) { |
1273 |
|
|
subListRangeCheck(fromIndex, toIndex, size); |
1274 |
jsr166 |
1.33 |
return new SubList<>(this, fromIndex, toIndex); |
1275 |
jsr166 |
1.26 |
} |
1276 |
|
|
|
1277 |
|
|
private void rangeCheckForAdd(int index) { |
1278 |
|
|
if (index < 0 || index > this.size) |
1279 |
|
|
throw new IndexOutOfBoundsException(outOfBoundsMsg(index)); |
1280 |
|
|
} |
1281 |
|
|
|
1282 |
|
|
private String outOfBoundsMsg(int index) { |
1283 |
|
|
return "Index: "+index+", Size: "+this.size; |
1284 |
|
|
} |
1285 |
|
|
|
1286 |
|
|
private void checkForComodification() { |
1287 |
jsr166 |
1.33 |
if (root.modCount != modCount) |
1288 |
jsr166 |
1.26 |
throw new ConcurrentModificationException(); |
1289 |
|
|
} |
1290 |
jsr166 |
1.33 |
|
1291 |
|
|
private void updateSizeAndModCount(int sizeChange) { |
1292 |
|
|
SubList<E> slist = this; |
1293 |
|
|
do { |
1294 |
|
|
slist.size += sizeChange; |
1295 |
|
|
slist.modCount = root.modCount; |
1296 |
|
|
slist = slist.parent; |
1297 |
|
|
} while (slist != null); |
1298 |
|
|
} |
1299 |
|
|
|
1300 |
|
|
public Spliterator<E> spliterator() { |
1301 |
|
|
checkForComodification(); |
1302 |
|
|
|
1303 |
jsr166 |
1.45 |
// ArrayListSpliterator not used here due to late-binding |
1304 |
|
|
return new Spliterator<E>() { |
1305 |
jsr166 |
1.33 |
private int index = offset; // current index, modified on advance/split |
1306 |
|
|
private int fence = -1; // -1 until used; then one past last index |
1307 |
|
|
private int expectedModCount; // initialized when fence set |
1308 |
|
|
|
1309 |
|
|
private int getFence() { // initialize fence to size on first use |
1310 |
|
|
int hi; // (a specialized variant appears in method forEach) |
1311 |
|
|
if ((hi = fence) < 0) { |
1312 |
|
|
expectedModCount = modCount; |
1313 |
|
|
hi = fence = offset + size; |
1314 |
|
|
} |
1315 |
|
|
return hi; |
1316 |
|
|
} |
1317 |
|
|
|
1318 |
jsr166 |
1.45 |
public ArrayList<E>.ArrayListSpliterator trySplit() { |
1319 |
jsr166 |
1.33 |
int hi = getFence(), lo = index, mid = (lo + hi) >>> 1; |
1320 |
jsr166 |
1.45 |
// ArrayListSpliterator can be used here as the source is already bound |
1321 |
jsr166 |
1.33 |
return (lo >= mid) ? null : // divide range in half unless too small |
1322 |
jsr166 |
1.45 |
root.new ArrayListSpliterator(lo, index = mid, expectedModCount); |
1323 |
jsr166 |
1.33 |
} |
1324 |
|
|
|
1325 |
|
|
public boolean tryAdvance(Consumer<? super E> action) { |
1326 |
|
|
Objects.requireNonNull(action); |
1327 |
|
|
int hi = getFence(), i = index; |
1328 |
|
|
if (i < hi) { |
1329 |
|
|
index = i + 1; |
1330 |
|
|
@SuppressWarnings("unchecked") E e = (E)root.elementData[i]; |
1331 |
|
|
action.accept(e); |
1332 |
|
|
if (root.modCount != expectedModCount) |
1333 |
|
|
throw new ConcurrentModificationException(); |
1334 |
|
|
return true; |
1335 |
|
|
} |
1336 |
|
|
return false; |
1337 |
|
|
} |
1338 |
|
|
|
1339 |
|
|
public void forEachRemaining(Consumer<? super E> action) { |
1340 |
|
|
Objects.requireNonNull(action); |
1341 |
|
|
int i, hi, mc; // hoist accesses and checks from loop |
1342 |
|
|
ArrayList<E> lst = root; |
1343 |
|
|
Object[] a; |
1344 |
|
|
if ((a = lst.elementData) != null) { |
1345 |
|
|
if ((hi = fence) < 0) { |
1346 |
|
|
mc = modCount; |
1347 |
|
|
hi = offset + size; |
1348 |
|
|
} |
1349 |
|
|
else |
1350 |
|
|
mc = expectedModCount; |
1351 |
|
|
if ((i = index) >= 0 && (index = hi) <= a.length) { |
1352 |
|
|
for (; i < hi; ++i) { |
1353 |
|
|
@SuppressWarnings("unchecked") E e = (E) a[i]; |
1354 |
|
|
action.accept(e); |
1355 |
|
|
} |
1356 |
|
|
if (lst.modCount == mc) |
1357 |
|
|
return; |
1358 |
|
|
} |
1359 |
|
|
} |
1360 |
|
|
throw new ConcurrentModificationException(); |
1361 |
|
|
} |
1362 |
|
|
|
1363 |
|
|
public long estimateSize() { |
1364 |
jsr166 |
1.45 |
return getFence() - index; |
1365 |
jsr166 |
1.33 |
} |
1366 |
|
|
|
1367 |
|
|
public int characteristics() { |
1368 |
|
|
return Spliterator.ORDERED | Spliterator.SIZED | Spliterator.SUBSIZED; |
1369 |
|
|
} |
1370 |
|
|
}; |
1371 |
|
|
} |
1372 |
|
|
} |
1373 |
|
|
|
1374 |
jsr166 |
1.48 |
/** |
1375 |
|
|
* @throws NullPointerException {@inheritDoc} |
1376 |
|
|
*/ |
1377 |
jsr166 |
1.33 |
@Override |
1378 |
|
|
public void forEach(Consumer<? super E> action) { |
1379 |
|
|
Objects.requireNonNull(action); |
1380 |
|
|
final int expectedModCount = modCount; |
1381 |
jsr166 |
1.39 |
final Object[] es = elementData; |
1382 |
jsr166 |
1.33 |
final int size = this.size; |
1383 |
jsr166 |
1.41 |
for (int i = 0; modCount == expectedModCount && i < size; i++) |
1384 |
jsr166 |
1.39 |
action.accept(elementAt(es, i)); |
1385 |
jsr166 |
1.41 |
if (modCount != expectedModCount) |
1386 |
jsr166 |
1.33 |
throw new ConcurrentModificationException(); |
1387 |
|
|
} |
1388 |
|
|
|
1389 |
|
|
/** |
1390 |
|
|
* Creates a <em><a href="Spliterator.html#binding">late-binding</a></em> |
1391 |
|
|
* and <em>fail-fast</em> {@link Spliterator} over the elements in this |
1392 |
|
|
* list. |
1393 |
|
|
* |
1394 |
|
|
* <p>The {@code Spliterator} reports {@link Spliterator#SIZED}, |
1395 |
|
|
* {@link Spliterator#SUBSIZED}, and {@link Spliterator#ORDERED}. |
1396 |
|
|
* Overriding implementations should document the reporting of additional |
1397 |
|
|
* characteristic values. |
1398 |
|
|
* |
1399 |
|
|
* @return a {@code Spliterator} over the elements in this list |
1400 |
|
|
* @since 1.8 |
1401 |
|
|
*/ |
1402 |
|
|
@Override |
1403 |
|
|
public Spliterator<E> spliterator() { |
1404 |
jsr166 |
1.45 |
return new ArrayListSpliterator(0, -1, 0); |
1405 |
jsr166 |
1.33 |
} |
1406 |
|
|
|
1407 |
|
|
/** Index-based split-by-two, lazily initialized Spliterator */ |
1408 |
jsr166 |
1.45 |
final class ArrayListSpliterator implements Spliterator<E> { |
1409 |
jsr166 |
1.33 |
|
1410 |
|
|
/* |
1411 |
|
|
* If ArrayLists were immutable, or structurally immutable (no |
1412 |
|
|
* adds, removes, etc), we could implement their spliterators |
1413 |
|
|
* with Arrays.spliterator. Instead we detect as much |
1414 |
|
|
* interference during traversal as practical without |
1415 |
|
|
* sacrificing much performance. We rely primarily on |
1416 |
|
|
* modCounts. These are not guaranteed to detect concurrency |
1417 |
|
|
* violations, and are sometimes overly conservative about |
1418 |
|
|
* within-thread interference, but detect enough problems to |
1419 |
|
|
* be worthwhile in practice. To carry this out, we (1) lazily |
1420 |
|
|
* initialize fence and expectedModCount until the latest |
1421 |
|
|
* point that we need to commit to the state we are checking |
1422 |
|
|
* against; thus improving precision. (This doesn't apply to |
1423 |
|
|
* SubLists, that create spliterators with current non-lazy |
1424 |
|
|
* values). (2) We perform only a single |
1425 |
|
|
* ConcurrentModificationException check at the end of forEach |
1426 |
|
|
* (the most performance-sensitive method). When using forEach |
1427 |
|
|
* (as opposed to iterators), we can normally only detect |
1428 |
|
|
* interference after actions, not before. Further |
1429 |
|
|
* CME-triggering checks apply to all other possible |
1430 |
|
|
* violations of assumptions for example null or too-small |
1431 |
|
|
* elementData array given its size(), that could only have |
1432 |
|
|
* occurred due to interference. This allows the inner loop |
1433 |
|
|
* of forEach to run without any further checks, and |
1434 |
|
|
* simplifies lambda-resolution. While this does entail a |
1435 |
|
|
* number of checks, note that in the common case of |
1436 |
|
|
* list.stream().forEach(a), no checks or other computation |
1437 |
|
|
* occur anywhere other than inside forEach itself. The other |
1438 |
|
|
* less-often-used methods cannot take advantage of most of |
1439 |
|
|
* these streamlinings. |
1440 |
|
|
*/ |
1441 |
|
|
|
1442 |
|
|
private int index; // current index, modified on advance/split |
1443 |
|
|
private int fence; // -1 until used; then one past last index |
1444 |
|
|
private int expectedModCount; // initialized when fence set |
1445 |
|
|
|
1446 |
jsr166 |
1.49 |
/** Creates new spliterator covering the given range. */ |
1447 |
jsr166 |
1.45 |
ArrayListSpliterator(int origin, int fence, int expectedModCount) { |
1448 |
jsr166 |
1.33 |
this.index = origin; |
1449 |
|
|
this.fence = fence; |
1450 |
|
|
this.expectedModCount = expectedModCount; |
1451 |
|
|
} |
1452 |
|
|
|
1453 |
|
|
private int getFence() { // initialize fence to size on first use |
1454 |
|
|
int hi; // (a specialized variant appears in method forEach) |
1455 |
|
|
if ((hi = fence) < 0) { |
1456 |
jsr166 |
1.45 |
expectedModCount = modCount; |
1457 |
|
|
hi = fence = size; |
1458 |
jsr166 |
1.33 |
} |
1459 |
|
|
return hi; |
1460 |
|
|
} |
1461 |
|
|
|
1462 |
jsr166 |
1.45 |
public ArrayListSpliterator trySplit() { |
1463 |
jsr166 |
1.33 |
int hi = getFence(), lo = index, mid = (lo + hi) >>> 1; |
1464 |
|
|
return (lo >= mid) ? null : // divide range in half unless too small |
1465 |
jsr166 |
1.45 |
new ArrayListSpliterator(lo, index = mid, expectedModCount); |
1466 |
jsr166 |
1.33 |
} |
1467 |
|
|
|
1468 |
|
|
public boolean tryAdvance(Consumer<? super E> action) { |
1469 |
|
|
if (action == null) |
1470 |
|
|
throw new NullPointerException(); |
1471 |
|
|
int hi = getFence(), i = index; |
1472 |
|
|
if (i < hi) { |
1473 |
|
|
index = i + 1; |
1474 |
jsr166 |
1.45 |
@SuppressWarnings("unchecked") E e = (E)elementData[i]; |
1475 |
jsr166 |
1.33 |
action.accept(e); |
1476 |
jsr166 |
1.45 |
if (modCount != expectedModCount) |
1477 |
jsr166 |
1.33 |
throw new ConcurrentModificationException(); |
1478 |
|
|
return true; |
1479 |
|
|
} |
1480 |
|
|
return false; |
1481 |
|
|
} |
1482 |
|
|
|
1483 |
|
|
public void forEachRemaining(Consumer<? super E> action) { |
1484 |
|
|
int i, hi, mc; // hoist accesses and checks from loop |
1485 |
jsr166 |
1.45 |
Object[] a; |
1486 |
jsr166 |
1.33 |
if (action == null) |
1487 |
|
|
throw new NullPointerException(); |
1488 |
jsr166 |
1.45 |
if ((a = elementData) != null) { |
1489 |
jsr166 |
1.33 |
if ((hi = fence) < 0) { |
1490 |
jsr166 |
1.45 |
mc = modCount; |
1491 |
|
|
hi = size; |
1492 |
jsr166 |
1.33 |
} |
1493 |
|
|
else |
1494 |
|
|
mc = expectedModCount; |
1495 |
|
|
if ((i = index) >= 0 && (index = hi) <= a.length) { |
1496 |
|
|
for (; i < hi; ++i) { |
1497 |
|
|
@SuppressWarnings("unchecked") E e = (E) a[i]; |
1498 |
|
|
action.accept(e); |
1499 |
|
|
} |
1500 |
jsr166 |
1.45 |
if (modCount == mc) |
1501 |
jsr166 |
1.33 |
return; |
1502 |
|
|
} |
1503 |
|
|
} |
1504 |
|
|
throw new ConcurrentModificationException(); |
1505 |
|
|
} |
1506 |
|
|
|
1507 |
|
|
public long estimateSize() { |
1508 |
jsr166 |
1.45 |
return getFence() - index; |
1509 |
jsr166 |
1.33 |
} |
1510 |
|
|
|
1511 |
|
|
public int characteristics() { |
1512 |
|
|
return Spliterator.ORDERED | Spliterator.SIZED | Spliterator.SUBSIZED; |
1513 |
|
|
} |
1514 |
|
|
} |
1515 |
|
|
|
1516 |
jsr166 |
1.39 |
// A tiny bit set implementation |
1517 |
|
|
|
1518 |
|
|
private static long[] nBits(int n) { |
1519 |
|
|
return new long[((n - 1) >> 6) + 1]; |
1520 |
|
|
} |
1521 |
|
|
private static void setBit(long[] bits, int i) { |
1522 |
|
|
bits[i >> 6] |= 1L << i; |
1523 |
|
|
} |
1524 |
|
|
private static boolean isClear(long[] bits, int i) { |
1525 |
|
|
return (bits[i >> 6] & (1L << i)) == 0; |
1526 |
|
|
} |
1527 |
|
|
|
1528 |
jsr166 |
1.48 |
/** |
1529 |
|
|
* @throws NullPointerException {@inheritDoc} |
1530 |
|
|
*/ |
1531 |
jsr166 |
1.33 |
@Override |
1532 |
jsr166 |
1.40 |
public boolean removeIf(Predicate<? super E> filter) { |
1533 |
|
|
return removeIf(filter, 0, size); |
1534 |
|
|
} |
1535 |
|
|
|
1536 |
jsr166 |
1.43 |
/** |
1537 |
|
|
* Removes all elements satisfying the given predicate, from index |
1538 |
|
|
* i (inclusive) to index end (exclusive). |
1539 |
|
|
*/ |
1540 |
|
|
boolean removeIf(Predicate<? super E> filter, int i, final int end) { |
1541 |
jsr166 |
1.33 |
Objects.requireNonNull(filter); |
1542 |
jsr166 |
1.36 |
int expectedModCount = modCount; |
1543 |
|
|
final Object[] es = elementData; |
1544 |
jsr166 |
1.37 |
// Optimize for initial run of survivors |
1545 |
jsr166 |
1.43 |
for (; i < end && !filter.test(elementAt(es, i)); i++) |
1546 |
jsr166 |
1.38 |
; |
1547 |
jsr166 |
1.39 |
// Tolerate predicates that reentrantly access the collection for |
1548 |
|
|
// read (but writers still get CME), so traverse once to find |
1549 |
|
|
// elements to delete, a second pass to physically expunge. |
1550 |
jsr166 |
1.43 |
if (i < end) { |
1551 |
jsr166 |
1.39 |
final int beg = i; |
1552 |
|
|
final long[] deathRow = nBits(end - beg); |
1553 |
|
|
deathRow[0] = 1L; // set bit 0 |
1554 |
|
|
for (i = beg + 1; i < end; i++) |
1555 |
|
|
if (filter.test(elementAt(es, i))) |
1556 |
|
|
setBit(deathRow, i - beg); |
1557 |
jsr166 |
1.40 |
if (modCount != expectedModCount) |
1558 |
|
|
throw new ConcurrentModificationException(); |
1559 |
jsr166 |
1.43 |
expectedModCount++; |
1560 |
|
|
modCount++; |
1561 |
jsr166 |
1.39 |
int w = beg; |
1562 |
|
|
for (i = beg; i < end; i++) |
1563 |
|
|
if (isClear(deathRow, i - beg)) |
1564 |
|
|
es[w++] = es[i]; |
1565 |
jsr166 |
1.47 |
shiftTailOverGap(es, w, end); |
1566 |
jsr166 |
1.43 |
// checkInvariants(); |
1567 |
|
|
return true; |
1568 |
|
|
} else { |
1569 |
|
|
if (modCount != expectedModCount) |
1570 |
|
|
throw new ConcurrentModificationException(); |
1571 |
|
|
// checkInvariants(); |
1572 |
|
|
return false; |
1573 |
jsr166 |
1.33 |
} |
1574 |
|
|
} |
1575 |
|
|
|
1576 |
|
|
@Override |
1577 |
|
|
public void replaceAll(UnaryOperator<E> operator) { |
1578 |
|
|
Objects.requireNonNull(operator); |
1579 |
|
|
final int expectedModCount = modCount; |
1580 |
jsr166 |
1.39 |
final Object[] es = elementData; |
1581 |
jsr166 |
1.33 |
final int size = this.size; |
1582 |
jsr166 |
1.41 |
for (int i = 0; modCount == expectedModCount && i < size; i++) |
1583 |
jsr166 |
1.39 |
es[i] = operator.apply(elementAt(es, i)); |
1584 |
jsr166 |
1.41 |
if (modCount != expectedModCount) |
1585 |
jsr166 |
1.33 |
throw new ConcurrentModificationException(); |
1586 |
|
|
modCount++; |
1587 |
jsr166 |
1.41 |
// checkInvariants(); |
1588 |
jsr166 |
1.33 |
} |
1589 |
|
|
|
1590 |
|
|
@Override |
1591 |
|
|
@SuppressWarnings("unchecked") |
1592 |
|
|
public void sort(Comparator<? super E> c) { |
1593 |
|
|
final int expectedModCount = modCount; |
1594 |
|
|
Arrays.sort((E[]) elementData, 0, size, c); |
1595 |
jsr166 |
1.41 |
if (modCount != expectedModCount) |
1596 |
jsr166 |
1.33 |
throw new ConcurrentModificationException(); |
1597 |
|
|
modCount++; |
1598 |
jsr166 |
1.41 |
// checkInvariants(); |
1599 |
|
|
} |
1600 |
|
|
|
1601 |
|
|
void checkInvariants() { |
1602 |
|
|
// assert size >= 0; |
1603 |
|
|
// assert size == elementData.length || elementData[size] == null; |
1604 |
jsr166 |
1.25 |
} |
1605 |
dl |
1.1 |
} |