1 |
dl |
1.2 |
/* |
2 |
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* Written by Doug Lea with assistance from members of JCP JSR-166 |
3 |
dl |
1.17 |
* Expert Group. Adapted and released, under explicit permission, |
4 |
dl |
1.15 |
* from JDK ArrayList.java which carries the following copyright: |
5 |
dl |
1.3 |
* |
6 |
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* Copyright 1997 by Sun Microsystems, Inc., |
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* 901 San Antonio Road, Palo Alto, California, 94303, U.S.A. |
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* All rights reserved. |
9 |
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* |
10 |
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* This software is the confidential and proprietary information |
11 |
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* of Sun Microsystems, Inc. ("Confidential Information"). You |
12 |
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* shall not disclose such Confidential Information and shall use |
13 |
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* it only in accordance with the terms of the license agreement |
14 |
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* you entered into with Sun. |
15 |
dl |
1.2 |
*/ |
16 |
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|
17 |
tim |
1.1 |
package java.util.concurrent; |
18 |
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import java.util.*; |
19 |
dl |
1.42 |
import java.util.concurrent.locks.*; |
20 |
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import sun.misc.*; |
21 |
tim |
1.1 |
|
22 |
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/** |
23 |
dl |
1.28 |
* A thread-safe variant of {@link java.util.ArrayList} in which all mutative |
24 |
jsr166 |
1.35 |
* operations (<tt>add</tt>, <tt>set</tt>, and so on) are implemented by |
25 |
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* making a fresh copy of the underlying array. |
26 |
tim |
1.1 |
* |
27 |
dl |
1.26 |
* <p> This is ordinarily too costly, but may be <em>more</em> efficient |
28 |
dl |
1.12 |
* than alternatives when traversal operations vastly outnumber |
29 |
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* mutations, and is useful when you cannot or don't want to |
30 |
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* synchronize traversals, yet need to preclude interference among |
31 |
dl |
1.15 |
* concurrent threads. The "snapshot" style iterator method uses a |
32 |
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* reference to the state of the array at the point that the iterator |
33 |
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* was created. This array never changes during the lifetime of the |
34 |
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* iterator, so interference is impossible and the iterator is |
35 |
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* guaranteed not to throw <tt>ConcurrentModificationException</tt>. |
36 |
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* The iterator will not reflect additions, removals, or changes to |
37 |
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* the list since the iterator was created. Element-changing |
38 |
jsr166 |
1.35 |
* operations on iterators themselves (<tt>remove</tt>, <tt>set</tt>, and |
39 |
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* <tt>add</tt>) are not supported. These methods throw |
40 |
dl |
1.15 |
* <tt>UnsupportedOperationException</tt>. |
41 |
dl |
1.24 |
* |
42 |
jsr166 |
1.35 |
* <p>All elements are permitted, including <tt>null</tt>. |
43 |
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* |
44 |
dl |
1.24 |
* <p>This class is a member of the |
45 |
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* <a href="{@docRoot}/../guide/collections/index.html"> |
46 |
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* Java Collections Framework</a>. |
47 |
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* |
48 |
dl |
1.6 |
* @since 1.5 |
49 |
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* @author Doug Lea |
50 |
dl |
1.19 |
* @param <E> the type of elements held in this collection |
51 |
dl |
1.6 |
*/ |
52 |
tim |
1.1 |
public class CopyOnWriteArrayList<E> |
53 |
dl |
1.40 |
implements List<E>, RandomAccess, Cloneable, java.io.Serializable { |
54 |
dl |
1.11 |
private static final long serialVersionUID = 8673264195747942595L; |
55 |
tim |
1.1 |
|
56 |
dl |
1.42 |
/** The lock protecting all mutators */ |
57 |
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transient final ReentrantLock lock = new ReentrantLock(); |
58 |
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59 |
dl |
1.40 |
/** The array, accessed only via getArray/setArray. */ |
60 |
dl |
1.41 |
private volatile transient Object[] array; |
61 |
tim |
1.1 |
|
62 |
dl |
1.42 |
Object[] getArray() { return array; } |
63 |
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void setArray(Object[] a) { array = a; } |
64 |
tim |
1.1 |
|
65 |
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/** |
66 |
dl |
1.15 |
* Creates an empty list. |
67 |
tim |
1.1 |
*/ |
68 |
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public CopyOnWriteArrayList() { |
69 |
dl |
1.41 |
setArray(new Object[0]); |
70 |
tim |
1.1 |
} |
71 |
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72 |
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/** |
73 |
dl |
1.15 |
* Creates a list containing the elements of the specified |
74 |
jsr166 |
1.32 |
* collection, in the order they are returned by the collection's |
75 |
tim |
1.1 |
* iterator. |
76 |
jsr166 |
1.32 |
* |
77 |
dl |
1.6 |
* @param c the collection of initially held elements |
78 |
jsr166 |
1.35 |
* @throws NullPointerException if the specified collection is null |
79 |
tim |
1.1 |
*/ |
80 |
tim |
1.22 |
public CopyOnWriteArrayList(Collection<? extends E> c) { |
81 |
dl |
1.41 |
Object[] elements = new Object[c.size()]; |
82 |
tim |
1.1 |
int size = 0; |
83 |
dl |
1.41 |
for (E e : c) |
84 |
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elements[size++] = e; |
85 |
dl |
1.40 |
setArray(elements); |
86 |
tim |
1.1 |
} |
87 |
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|
88 |
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/** |
89 |
jsr166 |
1.35 |
* Creates a list holding a copy of the given array. |
90 |
tim |
1.9 |
* |
91 |
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* @param toCopyIn the array (a copy of this array is used as the |
92 |
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* internal array) |
93 |
jsr166 |
1.38 |
* @throws NullPointerException if the specified array is null |
94 |
jsr166 |
1.30 |
*/ |
95 |
tim |
1.1 |
public CopyOnWriteArrayList(E[] toCopyIn) { |
96 |
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copyIn(toCopyIn, 0, toCopyIn.length); |
97 |
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} |
98 |
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99 |
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/** |
100 |
jsr166 |
1.30 |
* Replaces the held array with a copy of the <tt>n</tt> elements |
101 |
dl |
1.25 |
* of the provided array, starting at position <tt>first</tt>. To |
102 |
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* copy an entire array, call with arguments (array, 0, |
103 |
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* array.length). |
104 |
tim |
1.1 |
* @param toCopyIn the array. A copy of the indicated elements of |
105 |
dl |
1.25 |
* this array is used as the internal array. |
106 |
tim |
1.1 |
* @param first The index of first position of the array to |
107 |
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* start copying from. |
108 |
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* @param n the number of elements to copy. This will be the new size of |
109 |
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* the list. |
110 |
jsr166 |
1.30 |
*/ |
111 |
dl |
1.42 |
private void copyIn(E[] toCopyIn, int first, int n) { |
112 |
dl |
1.40 |
int limit = first + n; |
113 |
dl |
1.41 |
if (limit > toCopyIn.length) |
114 |
dl |
1.40 |
throw new IndexOutOfBoundsException(); |
115 |
dl |
1.42 |
Object[] newElements = copyOfRange(toCopyIn, first, limit, |
116 |
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Object[].class); |
117 |
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final ReentrantLock lock = this.lock; |
118 |
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lock.lock(); |
119 |
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try { setArray(newElements); } |
120 |
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finally { lock.unlock(); } |
121 |
tim |
1.1 |
} |
122 |
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123 |
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/** |
124 |
dl |
1.15 |
* Returns the number of elements in this list. |
125 |
tim |
1.1 |
* |
126 |
jsr166 |
1.35 |
* @return the number of elements in this list |
127 |
tim |
1.1 |
*/ |
128 |
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public int size() { |
129 |
dl |
1.40 |
return getArray().length; |
130 |
tim |
1.1 |
} |
131 |
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132 |
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/** |
133 |
jsr166 |
1.35 |
* Returns <tt>true</tt> if this list contains no elements. |
134 |
tim |
1.1 |
* |
135 |
jsr166 |
1.35 |
* @return <tt>true</tt> if this list contains no elements |
136 |
tim |
1.1 |
*/ |
137 |
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public boolean isEmpty() { |
138 |
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return size() == 0; |
139 |
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} |
140 |
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|
141 |
dl |
1.43 |
|
142 |
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/** |
143 |
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* Test for equality, coping with nulls. |
144 |
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*/ |
145 |
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private static boolean eq(Object o1, Object o2) { |
146 |
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return (o1 == null ? o2 == null : o1.equals(o2)); |
147 |
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} |
148 |
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|
149 |
dl |
1.41 |
/** |
150 |
dl |
1.40 |
* static version of indexOf, to allow repeated calls without |
151 |
dl |
1.41 |
* needing to re-acquire array each time. |
152 |
dl |
1.40 |
* @param o element to search for |
153 |
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* @param elements the array |
154 |
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* @param index first index to search |
155 |
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* @param fence one past last index to search |
156 |
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* @return index of element, or -1 if absent |
157 |
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*/ |
158 |
dl |
1.41 |
private static int indexOf(Object o, Object[] elements, |
159 |
dl |
1.40 |
int index, int fence) { |
160 |
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if (o == null) { |
161 |
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for (int i = index; i < fence; i++) |
162 |
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if (elements[i] == null) |
163 |
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return i; |
164 |
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} else { |
165 |
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for (int i = index; i < fence; i++) |
166 |
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if (o.equals(elements[i])) |
167 |
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return i; |
168 |
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} |
169 |
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return -1; |
170 |
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} |
171 |
dl |
1.41 |
|
172 |
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/** |
173 |
dl |
1.40 |
* static version of lastIndexOf. |
174 |
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* @param o element to search for |
175 |
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* @param elements the array |
176 |
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* @param index first index to search |
177 |
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* @return index of element, or -1 if absent |
178 |
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*/ |
179 |
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private static int lastIndexOf(Object o, Object[] elements, int index) { |
180 |
|
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if (o == null) { |
181 |
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for (int i = index; i >= 0; i--) |
182 |
|
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if (elements[i] == null) |
183 |
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return i; |
184 |
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} else { |
185 |
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for (int i = index; i >= 0; i--) |
186 |
|
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if (o.equals(elements[i])) |
187 |
|
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return i; |
188 |
|
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} |
189 |
|
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return -1; |
190 |
|
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} |
191 |
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|
192 |
tim |
1.1 |
/** |
193 |
dl |
1.15 |
* Returns <tt>true</tt> if this list contains the specified element. |
194 |
jsr166 |
1.35 |
* More formally, returns <tt>true</tt> if and only if this list contains |
195 |
|
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* at least one element <tt>e</tt> such that |
196 |
|
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* <tt>(o==null ? e==null : o.equals(e))</tt>. |
197 |
tim |
1.1 |
* |
198 |
jsr166 |
1.35 |
* @param o element whose presence in this list is to be tested |
199 |
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* @return <tt>true</tt> if this list contains the specified element |
200 |
tim |
1.1 |
*/ |
201 |
jsr166 |
1.35 |
public boolean contains(Object o) { |
202 |
dl |
1.41 |
Object[] elements = getArray(); |
203 |
dl |
1.40 |
return indexOf(o, elements, 0, elements.length) >= 0; |
204 |
tim |
1.1 |
} |
205 |
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|
206 |
|
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/** |
207 |
jsr166 |
1.35 |
* {@inheritDoc} |
208 |
tim |
1.1 |
*/ |
209 |
jsr166 |
1.35 |
public int indexOf(Object o) { |
210 |
dl |
1.41 |
Object[] elements = getArray(); |
211 |
dl |
1.40 |
return indexOf(o, elements, 0, elements.length); |
212 |
tim |
1.1 |
} |
213 |
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|
214 |
|
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|
215 |
|
|
/** |
216 |
jsr166 |
1.35 |
* Returns the index of the first occurrence of the specified element in |
217 |
|
|
* this list, searching forwards from <tt>index</tt>, or returns -1 if |
218 |
|
|
* the element is not found. |
219 |
|
|
* More formally, returns the lowest index <tt>i</tt> such that |
220 |
|
|
* <tt>(i >= index && (e==null ? get(i)==null : e.equals(get(i))))</tt>, |
221 |
|
|
* or -1 if there is no such index. |
222 |
|
|
* |
223 |
|
|
* @param e element to search for |
224 |
|
|
* @param index index to start searching from |
225 |
|
|
* @return the index of the first occurrence of the element in |
226 |
|
|
* this list at position <tt>index</tt> or later in the list; |
227 |
|
|
* <tt>-1</tt> if the element is not found. |
228 |
|
|
* @throws IndexOutOfBoundsException if the specified index is negative |
229 |
tim |
1.1 |
*/ |
230 |
jsr166 |
1.35 |
public int indexOf(E e, int index) { |
231 |
dl |
1.41 |
Object[] elements = getArray(); |
232 |
dl |
1.40 |
return indexOf(e, elements, index, elements.length); |
233 |
tim |
1.1 |
} |
234 |
|
|
|
235 |
|
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/** |
236 |
jsr166 |
1.35 |
* {@inheritDoc} |
237 |
tim |
1.1 |
*/ |
238 |
jsr166 |
1.35 |
public int lastIndexOf(Object o) { |
239 |
dl |
1.41 |
Object[] elements = getArray(); |
240 |
dl |
1.40 |
return lastIndexOf(o, elements, elements.length - 1); |
241 |
tim |
1.1 |
} |
242 |
|
|
|
243 |
|
|
/** |
244 |
jsr166 |
1.35 |
* Returns the index of the last occurrence of the specified element in |
245 |
|
|
* this list, searching backwards from <tt>index</tt>, or returns -1 if |
246 |
|
|
* the element is not found. |
247 |
|
|
* More formally, returns the highest index <tt>i</tt> such that |
248 |
|
|
* <tt>(i <= index && (e==null ? get(i)==null : e.equals(get(i))))</tt>, |
249 |
|
|
* or -1 if there is no such index. |
250 |
|
|
* |
251 |
|
|
* @param e element to search for |
252 |
|
|
* @param index index to start searching backwards from |
253 |
|
|
* @return the index of the last occurrence of the element at position |
254 |
|
|
* less than or equal to <tt>index</tt> in this list; |
255 |
|
|
* -1 if the element is not found. |
256 |
|
|
* @throws IndexOutOfBoundsException if the specified index is greater |
257 |
|
|
* than or equal to the current size of this list |
258 |
tim |
1.1 |
*/ |
259 |
jsr166 |
1.35 |
public int lastIndexOf(E e, int index) { |
260 |
dl |
1.41 |
Object[] elements = getArray(); |
261 |
dl |
1.40 |
return lastIndexOf(e, elements, index); |
262 |
tim |
1.1 |
} |
263 |
|
|
|
264 |
|
|
/** |
265 |
|
|
* Returns a shallow copy of this list. (The elements themselves |
266 |
|
|
* are not copied.) |
267 |
|
|
* |
268 |
jsr166 |
1.35 |
* @return a clone of this list |
269 |
tim |
1.1 |
*/ |
270 |
|
|
public Object clone() { |
271 |
|
|
try { |
272 |
dl |
1.41 |
return super.clone(); |
273 |
tim |
1.1 |
} catch (CloneNotSupportedException e) { |
274 |
|
|
// this shouldn't happen, since we are Cloneable |
275 |
|
|
throw new InternalError(); |
276 |
|
|
} |
277 |
|
|
} |
278 |
|
|
|
279 |
|
|
/** |
280 |
|
|
* Returns an array containing all of the elements in this list |
281 |
jsr166 |
1.35 |
* in proper sequence (from first to last element). |
282 |
|
|
* |
283 |
|
|
* <p>The returned array will be "safe" in that no references to it are |
284 |
|
|
* maintained by this list. (In other words, this method must allocate |
285 |
|
|
* a new array). The caller is thus free to modify the returned array. |
286 |
jsr166 |
1.36 |
* |
287 |
jsr166 |
1.35 |
* <p>This method acts as bridge between array-based and collection-based |
288 |
|
|
* APIs. |
289 |
|
|
* |
290 |
|
|
* @return an array containing all the elements in this list |
291 |
tim |
1.1 |
*/ |
292 |
|
|
public Object[] toArray() { |
293 |
dl |
1.40 |
Object[] elements = getArray(); |
294 |
dl |
1.42 |
return copyOf(elements, elements.length); |
295 |
tim |
1.1 |
} |
296 |
|
|
|
297 |
|
|
/** |
298 |
jsr166 |
1.35 |
* Returns an array containing all of the elements in this list in |
299 |
|
|
* proper sequence (from first to last element); the runtime type of |
300 |
|
|
* the returned array is that of the specified array. If the list fits |
301 |
|
|
* in the specified array, it is returned therein. Otherwise, a new |
302 |
|
|
* array is allocated with the runtime type of the specified array and |
303 |
|
|
* the size of this list. |
304 |
jsr166 |
1.32 |
* |
305 |
|
|
* <p>If this list fits in the specified array with room to spare |
306 |
jsr166 |
1.35 |
* (i.e., the array has more elements than this list), the element in |
307 |
|
|
* the array immediately following the end of the list is set to |
308 |
|
|
* <tt>null</tt>. (This is useful in determining the length of this |
309 |
|
|
* list <i>only</i> if the caller knows that this list does not contain |
310 |
|
|
* any null elements.) |
311 |
|
|
* |
312 |
|
|
* <p>Like the {@link #toArray()} method, this method acts as bridge between |
313 |
|
|
* array-based and collection-based APIs. Further, this method allows |
314 |
|
|
* precise control over the runtime type of the output array, and may, |
315 |
|
|
* under certain circumstances, be used to save allocation costs. |
316 |
|
|
* |
317 |
|
|
* <p>Suppose <tt>x</tt> is a list known to contain only strings. |
318 |
|
|
* The following code can be used to dump the list into a newly |
319 |
|
|
* allocated array of <tt>String</tt>: |
320 |
|
|
* |
321 |
|
|
* <pre> |
322 |
|
|
* String[] y = x.toArray(new String[0]);</pre> |
323 |
|
|
* |
324 |
|
|
* Note that <tt>toArray(new Object[0])</tt> is identical in function to |
325 |
|
|
* <tt>toArray()</tt>. |
326 |
tim |
1.1 |
* |
327 |
|
|
* @param a the array into which the elements of the list are to |
328 |
jsr166 |
1.35 |
* be stored, if it is big enough; otherwise, a new array of the |
329 |
|
|
* same runtime type is allocated for this purpose. |
330 |
|
|
* @return an array containing all the elements in this list |
331 |
|
|
* @throws ArrayStoreException if the runtime type of the specified array |
332 |
|
|
* is not a supertype of the runtime type of every element in |
333 |
|
|
* this list |
334 |
|
|
* @throws NullPointerException if the specified array is null |
335 |
tim |
1.1 |
*/ |
336 |
|
|
public <T> T[] toArray(T a[]) { |
337 |
dl |
1.41 |
Object[] elements = getArray(); |
338 |
dl |
1.40 |
int len = elements.length; |
339 |
|
|
if (a.length < len) |
340 |
dl |
1.42 |
return (T[]) copyOf(elements, len, a.getClass()); |
341 |
dl |
1.40 |
else { |
342 |
|
|
System.arraycopy(elements, 0, a, 0, len); |
343 |
|
|
if (a.length > len) |
344 |
|
|
a[len] = null; |
345 |
|
|
return a; |
346 |
|
|
} |
347 |
tim |
1.1 |
} |
348 |
|
|
|
349 |
|
|
// Positional Access Operations |
350 |
|
|
|
351 |
|
|
/** |
352 |
jsr166 |
1.35 |
* {@inheritDoc} |
353 |
tim |
1.1 |
* |
354 |
jsr166 |
1.35 |
* @throws IndexOutOfBoundsException {@inheritDoc} |
355 |
tim |
1.1 |
*/ |
356 |
|
|
public E get(int index) { |
357 |
dl |
1.41 |
return (E)(getArray()[index]); |
358 |
tim |
1.1 |
} |
359 |
|
|
|
360 |
|
|
/** |
361 |
jsr166 |
1.35 |
* Replaces the element at the specified position in this list with the |
362 |
|
|
* specified element. |
363 |
tim |
1.1 |
* |
364 |
jsr166 |
1.35 |
* @throws IndexOutOfBoundsException {@inheritDoc} |
365 |
tim |
1.1 |
*/ |
366 |
dl |
1.42 |
public E set(int index, E element) { |
367 |
|
|
final ReentrantLock lock = this.lock; |
368 |
|
|
lock.lock(); |
369 |
|
|
try { |
370 |
|
|
Object[] elements = getArray(); |
371 |
|
|
int len = elements.length; |
372 |
|
|
Object oldValue = elements[index]; |
373 |
dl |
1.40 |
|
374 |
dl |
1.43 |
if (oldValue != element) { |
375 |
dl |
1.42 |
Object[] newElements = copyOf(elements, len); |
376 |
|
|
newElements[index] = element; |
377 |
|
|
setArray(newElements); |
378 |
|
|
} |
379 |
|
|
return (E)oldValue; |
380 |
|
|
} finally { |
381 |
|
|
lock.unlock(); |
382 |
tim |
1.1 |
} |
383 |
|
|
} |
384 |
|
|
|
385 |
|
|
/** |
386 |
|
|
* Appends the specified element to the end of this list. |
387 |
|
|
* |
388 |
dl |
1.40 |
* @param e element to be appended to this list |
389 |
jsr166 |
1.35 |
* @return <tt>true</tt> (as per the spec for {@link Collection#add}) |
390 |
tim |
1.1 |
*/ |
391 |
dl |
1.42 |
public boolean add(E e) { |
392 |
|
|
final ReentrantLock lock = this.lock; |
393 |
|
|
lock.lock(); |
394 |
|
|
try { |
395 |
|
|
Object[] elements = getArray(); |
396 |
|
|
int len = elements.length; |
397 |
|
|
Object[] newElements = copyOf(elements, len + 1); |
398 |
|
|
newElements[len] = e; |
399 |
|
|
setArray(newElements); |
400 |
|
|
} finally { |
401 |
|
|
lock.unlock(); |
402 |
|
|
} |
403 |
tim |
1.1 |
return true; |
404 |
|
|
} |
405 |
|
|
|
406 |
|
|
/** |
407 |
|
|
* Inserts the specified element at the specified position in this |
408 |
|
|
* list. Shifts the element currently at that position (if any) and |
409 |
|
|
* any subsequent elements to the right (adds one to their indices). |
410 |
|
|
* |
411 |
jsr166 |
1.35 |
* @throws IndexOutOfBoundsException {@inheritDoc} |
412 |
tim |
1.1 |
*/ |
413 |
dl |
1.42 |
public void add(int index, E element) { |
414 |
|
|
final ReentrantLock lock = this.lock; |
415 |
|
|
lock.lock(); |
416 |
|
|
try { |
417 |
|
|
Object[] elements = getArray(); |
418 |
|
|
int len = elements.length; |
419 |
|
|
if (index > len || index < 0) |
420 |
|
|
throw new IndexOutOfBoundsException("Index: " + index+ |
421 |
|
|
", Size: " + len); |
422 |
|
|
Object[] newElements; |
423 |
|
|
int numMoved = len - index; |
424 |
|
|
if (numMoved == 0) |
425 |
|
|
newElements = copyOf(elements, len + 1); |
426 |
|
|
else { |
427 |
|
|
newElements = new Object[len + 1]; |
428 |
|
|
System.arraycopy(elements, 0, newElements, 0, index); |
429 |
|
|
System.arraycopy(elements, index, newElements, index + 1, |
430 |
|
|
numMoved); |
431 |
|
|
} |
432 |
|
|
newElements[index] = element; |
433 |
|
|
setArray(newElements); |
434 |
|
|
} finally { |
435 |
|
|
lock.unlock(); |
436 |
dl |
1.40 |
} |
437 |
tim |
1.1 |
} |
438 |
|
|
|
439 |
|
|
/** |
440 |
|
|
* Removes the element at the specified position in this list. |
441 |
|
|
* Shifts any subsequent elements to the left (subtracts one from their |
442 |
jsr166 |
1.35 |
* indices). Returns the element that was removed from the list. |
443 |
tim |
1.1 |
* |
444 |
jsr166 |
1.35 |
* @throws IndexOutOfBoundsException {@inheritDoc} |
445 |
tim |
1.1 |
*/ |
446 |
dl |
1.42 |
public E remove(int index) { |
447 |
|
|
Object oldValue; |
448 |
|
|
final ReentrantLock lock = this.lock; |
449 |
|
|
lock.lock(); |
450 |
|
|
try { |
451 |
|
|
Object[] elements = getArray(); |
452 |
|
|
int len = elements.length; |
453 |
|
|
oldValue = elements[index]; |
454 |
|
|
int numMoved = len - index - 1; |
455 |
|
|
if (numMoved == 0) |
456 |
|
|
setArray(copyOf(elements, len - 1)); |
457 |
|
|
else { |
458 |
|
|
Object[] newElements = new Object[len - 1]; |
459 |
|
|
System.arraycopy(elements, 0, newElements, 0, index); |
460 |
|
|
System.arraycopy(elements, index + 1, newElements, index, |
461 |
|
|
numMoved); |
462 |
|
|
setArray(newElements); |
463 |
|
|
} |
464 |
|
|
} finally { |
465 |
|
|
lock.unlock(); |
466 |
dl |
1.40 |
} |
467 |
dl |
1.41 |
return (E)oldValue; |
468 |
tim |
1.1 |
} |
469 |
|
|
|
470 |
|
|
/** |
471 |
jsr166 |
1.35 |
* Removes the first occurrence of the specified element from this list, |
472 |
|
|
* if it is present. If this list does not contain the element, it is |
473 |
|
|
* unchanged. More formally, removes the element with the lowest index |
474 |
|
|
* <tt>i</tt> such that |
475 |
|
|
* <tt>(o==null ? get(i)==null : o.equals(get(i)))</tt> |
476 |
|
|
* (if such an element exists). Returns <tt>true</tt> if this list |
477 |
|
|
* contained the specified element (or equivalently, if this list |
478 |
|
|
* changed as a result of the call). |
479 |
tim |
1.1 |
* |
480 |
jsr166 |
1.35 |
* @param o element to be removed from this list, if present |
481 |
|
|
* @return <tt>true</tt> if this list contained the specified element |
482 |
tim |
1.1 |
*/ |
483 |
dl |
1.42 |
public boolean remove(Object o) { |
484 |
|
|
final ReentrantLock lock = this.lock; |
485 |
|
|
lock.lock(); |
486 |
|
|
try { |
487 |
|
|
Object[] elements = getArray(); |
488 |
|
|
int len = elements.length; |
489 |
|
|
if (len != 0) { |
490 |
|
|
// Copy while searching for element to remove |
491 |
|
|
// This wins in the normal case of element being present |
492 |
|
|
int newlen = len - 1; |
493 |
|
|
Object[] newElements = new Object[newlen]; |
494 |
|
|
|
495 |
|
|
for (int i = 0; i < newlen; ++i) { |
496 |
dl |
1.43 |
if (eq(o, elements[i])) { |
497 |
dl |
1.42 |
// found one; copy remaining and exit |
498 |
|
|
for (int k = i + 1; k < len; ++k) |
499 |
|
|
newElements[k - 1] = elements[k]; |
500 |
|
|
setArray(newElements); |
501 |
|
|
return true; |
502 |
|
|
} else |
503 |
|
|
newElements[i] = elements[i]; |
504 |
|
|
} |
505 |
|
|
|
506 |
|
|
// special handling for last cell |
507 |
dl |
1.43 |
if (eq(o, elements[newlen])) { |
508 |
dl |
1.40 |
setArray(newElements); |
509 |
|
|
return true; |
510 |
dl |
1.42 |
} |
511 |
dl |
1.40 |
} |
512 |
dl |
1.42 |
return false; |
513 |
|
|
} finally { |
514 |
|
|
lock.unlock(); |
515 |
tim |
1.1 |
} |
516 |
|
|
} |
517 |
|
|
|
518 |
|
|
/** |
519 |
jsr166 |
1.35 |
* Removes from this list all of the elements whose index is between |
520 |
|
|
* <tt>fromIndex</tt>, inclusive, and <tt>toIndex</tt>, exclusive. |
521 |
|
|
* Shifts any succeeding elements to the left (reduces their index). |
522 |
dl |
1.15 |
* This call shortens the list by <tt>(toIndex - fromIndex)</tt> elements. |
523 |
|
|
* (If <tt>toIndex==fromIndex</tt>, this operation has no effect.) |
524 |
tim |
1.1 |
* |
525 |
jsr166 |
1.35 |
* @param fromIndex index of first element to be removed |
526 |
|
|
* @param toIndex index after last element to be removed |
527 |
dl |
1.29 |
* @throws IndexOutOfBoundsException if fromIndex or toIndex out of |
528 |
tim |
1.1 |
* range (fromIndex < 0 || fromIndex >= size() || toIndex |
529 |
jsr166 |
1.35 |
* > size() || toIndex < fromIndex) |
530 |
tim |
1.1 |
*/ |
531 |
dl |
1.42 |
private void removeRange(int fromIndex, int toIndex) { |
532 |
|
|
final ReentrantLock lock = this.lock; |
533 |
|
|
lock.lock(); |
534 |
|
|
try { |
535 |
|
|
Object[] elements = getArray(); |
536 |
|
|
int len = elements.length; |
537 |
tim |
1.1 |
|
538 |
dl |
1.42 |
if (fromIndex < 0 || fromIndex >= len || |
539 |
|
|
toIndex > len || toIndex < fromIndex) |
540 |
|
|
throw new IndexOutOfBoundsException(); |
541 |
|
|
int newlen = len - (toIndex - fromIndex); |
542 |
|
|
int numMoved = len - toIndex; |
543 |
|
|
if (numMoved == 0) |
544 |
|
|
setArray(copyOf(elements, newlen)); |
545 |
|
|
else { |
546 |
|
|
Object[] newElements = new Object[newlen]; |
547 |
|
|
System.arraycopy(elements, 0, newElements, 0, fromIndex); |
548 |
|
|
System.arraycopy(elements, toIndex, newElements, |
549 |
|
|
fromIndex, numMoved); |
550 |
|
|
setArray(newElements); |
551 |
|
|
} |
552 |
|
|
} finally { |
553 |
|
|
lock.unlock(); |
554 |
dl |
1.40 |
} |
555 |
tim |
1.1 |
} |
556 |
|
|
|
557 |
|
|
/** |
558 |
|
|
* Append the element if not present. |
559 |
jsr166 |
1.38 |
* |
560 |
dl |
1.40 |
* @param e element to be added to this list, if absent |
561 |
jsr166 |
1.38 |
* @return <tt>true</tt> if the element was added |
562 |
jsr166 |
1.30 |
*/ |
563 |
dl |
1.42 |
public boolean addIfAbsent(E e) { |
564 |
|
|
final ReentrantLock lock = this.lock; |
565 |
|
|
lock.lock(); |
566 |
|
|
try { |
567 |
|
|
// Copy while checking if already present. |
568 |
|
|
// This wins in the most common case where it is not present |
569 |
|
|
Object[] elements = getArray(); |
570 |
|
|
int len = elements.length; |
571 |
|
|
Object[] newElements = new Object[len + 1]; |
572 |
|
|
for (int i = 0; i < len; ++i) { |
573 |
dl |
1.43 |
if (eq(e, elements[i])) |
574 |
dl |
1.42 |
return false; // exit, throwing away copy |
575 |
|
|
else |
576 |
|
|
newElements[i] = elements[i]; |
577 |
|
|
} |
578 |
|
|
newElements[len] = e; |
579 |
|
|
setArray(newElements); |
580 |
|
|
return true; |
581 |
|
|
} finally { |
582 |
|
|
lock.unlock(); |
583 |
tim |
1.1 |
} |
584 |
|
|
} |
585 |
|
|
|
586 |
|
|
/** |
587 |
jsr166 |
1.35 |
* Returns <tt>true</tt> if this list contains all of the elements of the |
588 |
jsr166 |
1.32 |
* specified collection. |
589 |
jsr166 |
1.34 |
* |
590 |
jsr166 |
1.36 |
* @param c collection to be checked for containment in this list |
591 |
jsr166 |
1.35 |
* @return <tt>true</tt> if this list contains all of the elements of the |
592 |
|
|
* specified collection |
593 |
|
|
* @throws NullPointerException if the specified collection is null |
594 |
jsr166 |
1.38 |
* @see #contains(Object) |
595 |
tim |
1.1 |
*/ |
596 |
tim |
1.7 |
public boolean containsAll(Collection<?> c) { |
597 |
dl |
1.41 |
Object[] elements = getArray(); |
598 |
dl |
1.40 |
int len = elements.length; |
599 |
dl |
1.41 |
for (Object e : c) { |
600 |
|
|
if (indexOf(e, elements, 0, len) < 0) |
601 |
tim |
1.1 |
return false; |
602 |
dl |
1.40 |
} |
603 |
tim |
1.1 |
return true; |
604 |
|
|
} |
605 |
|
|
|
606 |
|
|
/** |
607 |
jsr166 |
1.32 |
* Removes from this list all of its elements that are contained in |
608 |
|
|
* the specified collection. This is a particularly expensive operation |
609 |
tim |
1.1 |
* in this class because of the need for an internal temporary array. |
610 |
|
|
* |
611 |
jsr166 |
1.35 |
* @param c collection containing elements to be removed from this list |
612 |
|
|
* @return <tt>true</tt> if this list changed as a result of the call |
613 |
jsr166 |
1.38 |
* @throws ClassCastException if the class of an element of this list |
614 |
|
|
* is incompatible with the specified collection (optional) |
615 |
|
|
* @throws NullPointerException if this list contains a null element and the |
616 |
|
|
* specified collection does not permit null elements (optional), |
617 |
|
|
* or if the specified collection is null |
618 |
|
|
* @see #remove(Object) |
619 |
tim |
1.1 |
*/ |
620 |
dl |
1.42 |
public boolean removeAll(Collection<?> c) { |
621 |
|
|
final ReentrantLock lock = this.lock; |
622 |
|
|
lock.lock(); |
623 |
|
|
try { |
624 |
|
|
Object[] elements = getArray(); |
625 |
|
|
int len = elements.length; |
626 |
|
|
if (len != 0) { |
627 |
|
|
// temp array holds those elements we know we want to keep |
628 |
|
|
int newlen = 0; |
629 |
|
|
Object[] temp = new Object[len]; |
630 |
|
|
for (int i = 0; i < len; ++i) { |
631 |
|
|
Object element = elements[i]; |
632 |
|
|
if (!c.contains(element)) |
633 |
|
|
temp[newlen++] = element; |
634 |
|
|
} |
635 |
|
|
if (newlen != len) { |
636 |
|
|
setArray(copyOfRange(temp, 0, newlen, Object[].class)); |
637 |
|
|
return true; |
638 |
|
|
} |
639 |
tim |
1.1 |
} |
640 |
dl |
1.42 |
return false; |
641 |
|
|
} finally { |
642 |
|
|
lock.unlock(); |
643 |
tim |
1.1 |
} |
644 |
|
|
} |
645 |
|
|
|
646 |
|
|
/** |
647 |
jsr166 |
1.32 |
* Retains only the elements in this list that are contained in the |
648 |
jsr166 |
1.35 |
* specified collection. In other words, removes from this list all of |
649 |
|
|
* its elements that are not contained in the specified collection. |
650 |
jsr166 |
1.32 |
* |
651 |
jsr166 |
1.35 |
* @param c collection containing elements to be retained in this list |
652 |
|
|
* @return <tt>true</tt> if this list changed as a result of the call |
653 |
jsr166 |
1.38 |
* @throws ClassCastException if the class of an element of this list |
654 |
|
|
* is incompatible with the specified collection (optional) |
655 |
|
|
* @throws NullPointerException if this list contains a null element and the |
656 |
|
|
* specified collection does not permit null elements (optional), |
657 |
|
|
* or if the specified collection is null |
658 |
|
|
* @see #remove(Object) |
659 |
tim |
1.1 |
*/ |
660 |
dl |
1.42 |
public boolean retainAll(Collection<?> c) { |
661 |
|
|
final ReentrantLock lock = this.lock; |
662 |
|
|
lock.lock(); |
663 |
|
|
try { |
664 |
|
|
Object[] elements = getArray(); |
665 |
|
|
int len = elements.length; |
666 |
|
|
if (len != 0) { |
667 |
|
|
int newlen = 0; |
668 |
|
|
Object[] temp = new Object[len]; |
669 |
|
|
for (int i = 0; i < len; ++i) { |
670 |
|
|
Object element = elements[i]; |
671 |
|
|
if (c.contains(element)) |
672 |
|
|
temp[newlen++] = element; |
673 |
|
|
} |
674 |
|
|
if (newlen != len) { |
675 |
|
|
setArray(copyOfRange(temp, 0, newlen, Object[].class)); |
676 |
|
|
return true; |
677 |
|
|
} |
678 |
tim |
1.1 |
} |
679 |
dl |
1.42 |
return false; |
680 |
|
|
} finally { |
681 |
|
|
lock.unlock(); |
682 |
tim |
1.1 |
} |
683 |
|
|
} |
684 |
|
|
|
685 |
|
|
/** |
686 |
jsr166 |
1.32 |
* Appends all of the elements in the specified collection that |
687 |
tim |
1.1 |
* are not already contained in this list, to the end of |
688 |
|
|
* this list, in the order that they are returned by the |
689 |
jsr166 |
1.32 |
* specified collection's iterator. |
690 |
tim |
1.1 |
* |
691 |
jsr166 |
1.36 |
* @param c collection containing elements to be added to this list |
692 |
tim |
1.1 |
* @return the number of elements added |
693 |
jsr166 |
1.35 |
* @throws NullPointerException if the specified collection is null |
694 |
jsr166 |
1.38 |
* @see #addIfAbsent(Object) |
695 |
tim |
1.1 |
*/ |
696 |
dl |
1.42 |
public int addAllAbsent(Collection<? extends E> c) { |
697 |
dl |
1.40 |
int added = 0; |
698 |
dl |
1.42 |
final ReentrantLock lock = this.lock; |
699 |
|
|
lock.lock(); |
700 |
|
|
try { |
701 |
|
|
int numNew = c.size(); |
702 |
|
|
if (numNew != 0) { |
703 |
|
|
Object[] elements = getArray(); |
704 |
|
|
int len = elements.length; |
705 |
|
|
|
706 |
|
|
Object[] temp = new Object[numNew]; |
707 |
|
|
for (E e : c) { |
708 |
|
|
if (indexOf(e, elements, 0, len) < 0 && |
709 |
|
|
indexOf(e, temp, 0, added) < 0) |
710 |
|
|
temp[added++] = e; |
711 |
|
|
} |
712 |
|
|
if (added != 0) { |
713 |
|
|
Object[] newElements = new Object[len + added]; |
714 |
|
|
System.arraycopy(elements, 0, newElements, 0, len); |
715 |
|
|
System.arraycopy(temp, 0, newElements, len, added); |
716 |
|
|
setArray(newElements); |
717 |
|
|
} |
718 |
tim |
1.1 |
} |
719 |
dl |
1.42 |
} finally { |
720 |
|
|
lock.unlock(); |
721 |
tim |
1.1 |
} |
722 |
|
|
return added; |
723 |
|
|
} |
724 |
|
|
|
725 |
|
|
/** |
726 |
|
|
* Removes all of the elements from this list. |
727 |
jsr166 |
1.38 |
* The list will be empty after this call returns. |
728 |
tim |
1.1 |
*/ |
729 |
dl |
1.42 |
public void clear() { |
730 |
|
|
final ReentrantLock lock = this.lock; |
731 |
|
|
lock.lock(); |
732 |
|
|
try { setArray(new Object[0]); } |
733 |
|
|
finally { lock.unlock(); } |
734 |
tim |
1.1 |
} |
735 |
|
|
|
736 |
|
|
/** |
737 |
jsr166 |
1.32 |
* Appends all of the elements in the specified collection to the end |
738 |
|
|
* of this list, in the order that they are returned by the specified |
739 |
|
|
* collection's iterator. |
740 |
tim |
1.1 |
* |
741 |
jsr166 |
1.36 |
* @param c collection containing elements to be added to this list |
742 |
jsr166 |
1.38 |
* @return <tt>true</tt> if this list changed as a result of the call |
743 |
jsr166 |
1.35 |
* @throws NullPointerException if the specified collection is null |
744 |
jsr166 |
1.38 |
* @see #add(Object) |
745 |
tim |
1.1 |
*/ |
746 |
dl |
1.42 |
public boolean addAll(Collection<? extends E> c) { |
747 |
tim |
1.1 |
int numNew = c.size(); |
748 |
dl |
1.41 |
if (numNew == 0) |
749 |
dl |
1.40 |
return false; |
750 |
dl |
1.42 |
final ReentrantLock lock = this.lock; |
751 |
|
|
lock.lock(); |
752 |
|
|
try { |
753 |
|
|
Object[] elements = getArray(); |
754 |
|
|
int len = elements.length; |
755 |
|
|
Object[] newElements = new Object[len + numNew]; |
756 |
|
|
System.arraycopy(elements, 0, newElements, 0, len); |
757 |
|
|
for (E e : c) |
758 |
|
|
newElements[len++] = e; |
759 |
|
|
setArray(newElements); |
760 |
|
|
} finally { |
761 |
|
|
lock.unlock(); |
762 |
|
|
} |
763 |
tim |
1.1 |
return true; |
764 |
|
|
} |
765 |
|
|
|
766 |
|
|
/** |
767 |
jsr166 |
1.35 |
* Inserts all of the elements in the specified collection into this |
768 |
tim |
1.1 |
* list, starting at the specified position. Shifts the element |
769 |
|
|
* currently at that position (if any) and any subsequent elements to |
770 |
|
|
* the right (increases their indices). The new elements will appear |
771 |
jsr166 |
1.38 |
* in this list in the order that they are returned by the |
772 |
|
|
* specified collection's iterator. |
773 |
tim |
1.1 |
* |
774 |
jsr166 |
1.35 |
* @param index index at which to insert the first element |
775 |
|
|
* from the specified collection |
776 |
jsr166 |
1.36 |
* @param c collection containing elements to be added to this list |
777 |
jsr166 |
1.35 |
* @return <tt>true</tt> if this list changed as a result of the call |
778 |
|
|
* @throws IndexOutOfBoundsException {@inheritDoc} |
779 |
|
|
* @throws NullPointerException if the specified collection is null |
780 |
jsr166 |
1.38 |
* @see #add(int,Object) |
781 |
tim |
1.1 |
*/ |
782 |
dl |
1.42 |
public boolean addAll(int index, Collection<? extends E> c) { |
783 |
tim |
1.1 |
int numNew = c.size(); |
784 |
dl |
1.42 |
final ReentrantLock lock = this.lock; |
785 |
|
|
lock.lock(); |
786 |
|
|
try { |
787 |
|
|
Object[] elements = getArray(); |
788 |
|
|
int len = elements.length; |
789 |
|
|
if (index > len || index < 0) |
790 |
|
|
throw new IndexOutOfBoundsException("Index: " + index + |
791 |
|
|
", Size: "+ len); |
792 |
|
|
if (numNew != 0) { |
793 |
|
|
int numMoved = len - index; |
794 |
|
|
Object[] newElements; |
795 |
|
|
if (numMoved == 0) |
796 |
|
|
newElements = copyOf(elements, len + numNew); |
797 |
|
|
else { |
798 |
|
|
newElements = new Object[len + numNew]; |
799 |
|
|
System.arraycopy(elements, index, newElements, |
800 |
|
|
index + numNew, numMoved); |
801 |
|
|
System.arraycopy(elements, index, newElements, |
802 |
|
|
index + numNew, numMoved); |
803 |
|
|
} |
804 |
|
|
for (E e : c) |
805 |
|
|
newElements[index++] = e; |
806 |
|
|
setArray(newElements); |
807 |
|
|
} |
808 |
|
|
} finally { |
809 |
|
|
lock.unlock(); |
810 |
dl |
1.40 |
} |
811 |
dl |
1.42 |
return numNew != 0; |
812 |
tim |
1.1 |
} |
813 |
|
|
|
814 |
|
|
/** |
815 |
|
|
* Save the state of the list to a stream (i.e., serialize it). |
816 |
|
|
* |
817 |
|
|
* @serialData The length of the array backing the list is emitted |
818 |
|
|
* (int), followed by all of its elements (each an Object) |
819 |
|
|
* in the proper order. |
820 |
dl |
1.6 |
* @param s the stream |
821 |
tim |
1.1 |
*/ |
822 |
|
|
private void writeObject(java.io.ObjectOutputStream s) |
823 |
|
|
throws java.io.IOException{ |
824 |
|
|
|
825 |
|
|
// Write out element count, and any hidden stuff |
826 |
|
|
s.defaultWriteObject(); |
827 |
|
|
|
828 |
dl |
1.41 |
Object[] elements = getArray(); |
829 |
dl |
1.40 |
int len = elements.length; |
830 |
tim |
1.1 |
// Write out array length |
831 |
dl |
1.40 |
s.writeInt(len); |
832 |
tim |
1.1 |
|
833 |
|
|
// Write out all elements in the proper order. |
834 |
dl |
1.40 |
for (int i = 0; i < len; i++) |
835 |
|
|
s.writeObject(elements[i]); |
836 |
tim |
1.1 |
} |
837 |
|
|
|
838 |
|
|
/** |
839 |
|
|
* Reconstitute the list from a stream (i.e., deserialize it). |
840 |
dl |
1.6 |
* @param s the stream |
841 |
tim |
1.1 |
*/ |
842 |
dl |
1.12 |
private void readObject(java.io.ObjectInputStream s) |
843 |
tim |
1.1 |
throws java.io.IOException, ClassNotFoundException { |
844 |
|
|
|
845 |
|
|
// Read in size, and any hidden stuff |
846 |
|
|
s.defaultReadObject(); |
847 |
|
|
|
848 |
dl |
1.42 |
// bind to new lock |
849 |
|
|
resetLock(); |
850 |
|
|
|
851 |
tim |
1.1 |
// Read in array length and allocate array |
852 |
dl |
1.40 |
int len = s.readInt(); |
853 |
dl |
1.41 |
Object[] elements = new Object[len]; |
854 |
tim |
1.1 |
|
855 |
|
|
// Read in all elements in the proper order. |
856 |
dl |
1.40 |
for (int i = 0; i < len; i++) |
857 |
dl |
1.41 |
elements[i] = s.readObject(); |
858 |
dl |
1.40 |
setArray(elements); |
859 |
dl |
1.42 |
|
860 |
tim |
1.1 |
} |
861 |
|
|
|
862 |
|
|
/** |
863 |
jsr166 |
1.32 |
* Returns a string representation of this list, containing |
864 |
tim |
1.1 |
* the String representation of each element. |
865 |
|
|
*/ |
866 |
|
|
public String toString() { |
867 |
dl |
1.41 |
Object[] elements = getArray(); |
868 |
dl |
1.40 |
int maxIndex = elements.length - 1; |
869 |
dl |
1.43 |
StringBuilder sb = new StringBuilder(); |
870 |
|
|
sb.append("["); |
871 |
tim |
1.1 |
for (int i = 0; i <= maxIndex; i++) { |
872 |
dl |
1.43 |
sb.append(String.valueOf(elements[i])); |
873 |
tim |
1.1 |
if (i < maxIndex) |
874 |
dl |
1.43 |
sb.append(", "); |
875 |
tim |
1.1 |
} |
876 |
dl |
1.43 |
sb.append("]"); |
877 |
|
|
return sb.toString(); |
878 |
tim |
1.1 |
} |
879 |
|
|
|
880 |
|
|
/** |
881 |
jsr166 |
1.35 |
* Compares the specified object with this list for equality. |
882 |
|
|
* Returns true if and only if the specified object is also a {@link |
883 |
|
|
* List}, both lists have the same size, and all corresponding pairs |
884 |
|
|
* of elements in the two lists are <em>equal</em>. (Two elements |
885 |
|
|
* <tt>e1</tt> and <tt>e2</tt> are <em>equal</em> if <tt>(e1==null ? |
886 |
|
|
* e2==null : e1.equals(e2))</tt>.) In other words, two lists are |
887 |
|
|
* defined to be equal if they contain the same elements in the same |
888 |
|
|
* order. |
889 |
tim |
1.1 |
* |
890 |
jsr166 |
1.35 |
* @param o the object to be compared for equality with this list |
891 |
|
|
* @return <tt>true</tt> if the specified object is equal to this list |
892 |
tim |
1.1 |
*/ |
893 |
|
|
public boolean equals(Object o) { |
894 |
|
|
if (o == this) |
895 |
|
|
return true; |
896 |
|
|
if (!(o instanceof List)) |
897 |
|
|
return false; |
898 |
|
|
|
899 |
dl |
1.43 |
List<?> l2 = (List<?>)(o); |
900 |
tim |
1.1 |
if (size() != l2.size()) |
901 |
|
|
return false; |
902 |
|
|
|
903 |
dl |
1.41 |
ListIterator<?> e1 = listIterator(); |
904 |
|
|
ListIterator<?> e2 = l2.listIterator(); |
905 |
jsr166 |
1.35 |
while (e1.hasNext()) { |
906 |
dl |
1.43 |
if (!eq(e1.next(), e2.next())) |
907 |
tim |
1.1 |
return false; |
908 |
|
|
} |
909 |
|
|
return true; |
910 |
|
|
} |
911 |
|
|
|
912 |
|
|
/** |
913 |
jsr166 |
1.35 |
* Returns the hash code value for this list. |
914 |
dl |
1.26 |
* |
915 |
|
|
* <p> This implementation uses the definition in {@link |
916 |
|
|
* List#hashCode}. |
917 |
dl |
1.15 |
* @return the hash code |
918 |
tim |
1.1 |
*/ |
919 |
|
|
public int hashCode() { |
920 |
|
|
int hashCode = 1; |
921 |
dl |
1.41 |
Object[] elements = getArray(); |
922 |
dl |
1.40 |
int len = elements.length; |
923 |
|
|
for (int i = 0; i < len; ++i) { |
924 |
dl |
1.41 |
Object obj = elements[i]; |
925 |
dl |
1.40 |
hashCode = 31 * hashCode + (obj == null ? 0 : obj.hashCode()); |
926 |
tim |
1.1 |
} |
927 |
|
|
return hashCode; |
928 |
|
|
} |
929 |
|
|
|
930 |
|
|
/** |
931 |
jsr166 |
1.35 |
* Returns an iterator over the elements in this list in proper sequence. |
932 |
|
|
* |
933 |
|
|
* <p>The returned iterator provides a snapshot of the state of the list |
934 |
|
|
* when the iterator was constructed. No synchronization is needed while |
935 |
|
|
* traversing the iterator. The iterator does <em>NOT</em> support the |
936 |
|
|
* <tt>remove</tt> method. |
937 |
|
|
* |
938 |
|
|
* @return an iterator over the elements in this list in proper sequence |
939 |
tim |
1.1 |
*/ |
940 |
|
|
public Iterator<E> iterator() { |
941 |
dl |
1.40 |
return new COWIterator<E>(getArray(), 0); |
942 |
tim |
1.1 |
} |
943 |
|
|
|
944 |
|
|
/** |
945 |
jsr166 |
1.35 |
* {@inheritDoc} |
946 |
tim |
1.1 |
* |
947 |
jsr166 |
1.35 |
* <p>The returned iterator provides a snapshot of the state of the list |
948 |
|
|
* when the iterator was constructed. No synchronization is needed while |
949 |
|
|
* traversing the iterator. The iterator does <em>NOT</em> support the |
950 |
|
|
* <tt>remove</tt>, <tt>set</tt> or <tt>add</tt> methods. |
951 |
tim |
1.1 |
*/ |
952 |
|
|
public ListIterator<E> listIterator() { |
953 |
dl |
1.40 |
return new COWIterator<E>(getArray(), 0); |
954 |
tim |
1.1 |
} |
955 |
|
|
|
956 |
|
|
/** |
957 |
jsr166 |
1.35 |
* {@inheritDoc} |
958 |
|
|
* |
959 |
|
|
* <p>The list iterator returned by this implementation will throw an |
960 |
|
|
* <tt>UnsupportedOperationException</tt> in its <tt>remove</tt>, |
961 |
|
|
* <tt>set</tt> and <tt>add</tt> methods. |
962 |
|
|
* |
963 |
|
|
* @throws IndexOutOfBoundsException {@inheritDoc} |
964 |
tim |
1.1 |
*/ |
965 |
|
|
public ListIterator<E> listIterator(final int index) { |
966 |
dl |
1.41 |
Object[] elements = getArray(); |
967 |
dl |
1.40 |
int len = elements.length; |
968 |
|
|
if (index < 0 || index > len) |
969 |
|
|
throw new IndexOutOfBoundsException("Index: " + index); |
970 |
tim |
1.1 |
|
971 |
dl |
1.40 |
return new COWIterator<E>(getArray(), index); |
972 |
tim |
1.1 |
} |
973 |
|
|
|
974 |
|
|
private static class COWIterator<E> implements ListIterator<E> { |
975 |
|
|
/** Snapshot of the array **/ |
976 |
dl |
1.41 |
private final Object[] snapshot; |
977 |
dl |
1.40 |
/** Index of element to be returned by subsequent call to next. */ |
978 |
tim |
1.1 |
private int cursor; |
979 |
|
|
|
980 |
dl |
1.41 |
private COWIterator(Object[] elements, int initialCursor) { |
981 |
tim |
1.1 |
cursor = initialCursor; |
982 |
dl |
1.40 |
snapshot = elements; |
983 |
tim |
1.1 |
} |
984 |
|
|
|
985 |
|
|
public boolean hasNext() { |
986 |
dl |
1.40 |
return cursor < snapshot.length; |
987 |
tim |
1.1 |
} |
988 |
|
|
|
989 |
|
|
public boolean hasPrevious() { |
990 |
|
|
return cursor > 0; |
991 |
|
|
} |
992 |
|
|
|
993 |
|
|
public E next() { |
994 |
|
|
try { |
995 |
dl |
1.41 |
return (E)(snapshot[cursor++]); |
996 |
tim |
1.10 |
} catch (IndexOutOfBoundsException ex) { |
997 |
tim |
1.1 |
throw new NoSuchElementException(); |
998 |
|
|
} |
999 |
|
|
} |
1000 |
|
|
|
1001 |
|
|
public E previous() { |
1002 |
|
|
try { |
1003 |
dl |
1.41 |
return (E)(snapshot[--cursor]); |
1004 |
jsr166 |
1.30 |
} catch (IndexOutOfBoundsException e) { |
1005 |
tim |
1.1 |
throw new NoSuchElementException(); |
1006 |
|
|
} |
1007 |
|
|
} |
1008 |
|
|
|
1009 |
|
|
public int nextIndex() { |
1010 |
|
|
return cursor; |
1011 |
|
|
} |
1012 |
|
|
|
1013 |
|
|
public int previousIndex() { |
1014 |
dl |
1.40 |
return cursor - 1; |
1015 |
tim |
1.1 |
} |
1016 |
|
|
|
1017 |
|
|
/** |
1018 |
|
|
* Not supported. Always throws UnsupportedOperationException. |
1019 |
jsr166 |
1.32 |
* @throws UnsupportedOperationException always; <tt>remove</tt> |
1020 |
|
|
* is not supported by this iterator. |
1021 |
tim |
1.1 |
*/ |
1022 |
|
|
public void remove() { |
1023 |
|
|
throw new UnsupportedOperationException(); |
1024 |
|
|
} |
1025 |
|
|
|
1026 |
|
|
/** |
1027 |
|
|
* Not supported. Always throws UnsupportedOperationException. |
1028 |
jsr166 |
1.32 |
* @throws UnsupportedOperationException always; <tt>set</tt> |
1029 |
|
|
* is not supported by this iterator. |
1030 |
tim |
1.1 |
*/ |
1031 |
jsr166 |
1.33 |
public void set(E e) { |
1032 |
tim |
1.1 |
throw new UnsupportedOperationException(); |
1033 |
|
|
} |
1034 |
|
|
|
1035 |
|
|
/** |
1036 |
|
|
* Not supported. Always throws UnsupportedOperationException. |
1037 |
jsr166 |
1.32 |
* @throws UnsupportedOperationException always; <tt>add</tt> |
1038 |
|
|
* is not supported by this iterator. |
1039 |
tim |
1.1 |
*/ |
1040 |
jsr166 |
1.33 |
public void add(E e) { |
1041 |
tim |
1.1 |
throw new UnsupportedOperationException(); |
1042 |
|
|
} |
1043 |
|
|
} |
1044 |
|
|
|
1045 |
|
|
/** |
1046 |
dl |
1.40 |
* Returns a view of the portion of this list between |
1047 |
|
|
* <tt>fromIndex</tt>, inclusive, and <tt>toIndex</tt>, exclusive. |
1048 |
|
|
* The returned list is backed by this list, so changes in the |
1049 |
|
|
* returned list are reflected in this list, and vice-versa. |
1050 |
|
|
* While mutative operations are supported, they are probably not |
1051 |
|
|
* very useful for CopyOnWriteArrayLists. |
1052 |
|
|
* |
1053 |
|
|
* <p>The semantics of the list returned by this method become |
1054 |
|
|
* undefined if the backing list (i.e., this list) is |
1055 |
|
|
* <i>structurally modified</i> in any way other than via the |
1056 |
|
|
* returned list. (Structural modifications are those that change |
1057 |
|
|
* the size of the list, or otherwise perturb it in such a fashion |
1058 |
|
|
* that iterations in progress may yield incorrect results.) |
1059 |
tim |
1.1 |
* |
1060 |
jsr166 |
1.35 |
* @param fromIndex low endpoint (inclusive) of the subList |
1061 |
|
|
* @param toIndex high endpoint (exclusive) of the subList |
1062 |
|
|
* @return a view of the specified range within this list |
1063 |
|
|
* @throws IndexOutOfBoundsException {@inheritDoc} |
1064 |
tim |
1.1 |
*/ |
1065 |
dl |
1.42 |
public List<E> subList(int fromIndex, int toIndex) { |
1066 |
|
|
final ReentrantLock lock = this.lock; |
1067 |
|
|
lock.lock(); |
1068 |
|
|
try { |
1069 |
|
|
Object[] elements = getArray(); |
1070 |
|
|
int len = elements.length; |
1071 |
|
|
if (fromIndex < 0 || toIndex > len || fromIndex > toIndex) |
1072 |
|
|
throw new IndexOutOfBoundsException(); |
1073 |
|
|
return new COWSubList<E>(this, fromIndex, toIndex); |
1074 |
|
|
} finally { |
1075 |
|
|
lock.unlock(); |
1076 |
|
|
} |
1077 |
tim |
1.1 |
} |
1078 |
|
|
|
1079 |
dl |
1.42 |
|
1080 |
|
|
/** |
1081 |
|
|
* Sublist for CopyOnWriteArrayList. |
1082 |
|
|
* This class extends AbstractList merely for convenience, to |
1083 |
|
|
* avoid having to define addAll, etc. This doesn't hurt, but |
1084 |
|
|
* is wasteful. This class does not need or use modCount |
1085 |
|
|
* mechanics in AbstractList, but does need to check for |
1086 |
|
|
* concurrent modification using similar mechanics. On each |
1087 |
|
|
* operation, the array that we expect the backing list to use |
1088 |
|
|
* is checked and updated. Since we do this for all of the |
1089 |
|
|
* base operations invoked by those defined in AbstractList, |
1090 |
|
|
* all is well. While inefficient, this is not worth |
1091 |
|
|
* improving. The kinds of list operations inherited from |
1092 |
|
|
* AbstractList are already so slow on COW sublists that |
1093 |
|
|
* adding a bit more space/time doesn't seem even noticeable. |
1094 |
|
|
*/ |
1095 |
tim |
1.1 |
private static class COWSubList<E> extends AbstractList<E> { |
1096 |
|
|
private final CopyOnWriteArrayList<E> l; |
1097 |
|
|
private final int offset; |
1098 |
|
|
private int size; |
1099 |
dl |
1.41 |
private Object[] expectedArray; |
1100 |
tim |
1.1 |
|
1101 |
|
|
private COWSubList(CopyOnWriteArrayList<E> list, |
1102 |
dl |
1.40 |
int fromIndex, int toIndex) { |
1103 |
tim |
1.1 |
l = list; |
1104 |
dl |
1.40 |
expectedArray = l.getArray(); |
1105 |
tim |
1.1 |
offset = fromIndex; |
1106 |
|
|
size = toIndex - fromIndex; |
1107 |
|
|
} |
1108 |
|
|
|
1109 |
|
|
// only call this holding l's lock |
1110 |
|
|
private void checkForComodification() { |
1111 |
dl |
1.40 |
if (l.getArray() != expectedArray) |
1112 |
tim |
1.1 |
throw new ConcurrentModificationException(); |
1113 |
|
|
} |
1114 |
|
|
|
1115 |
|
|
// only call this holding l's lock |
1116 |
|
|
private void rangeCheck(int index) { |
1117 |
dl |
1.40 |
if (index < 0 || index >= size) |
1118 |
|
|
throw new IndexOutOfBoundsException("Index: " + index + |
1119 |
|
|
",Size: " + size); |
1120 |
tim |
1.1 |
} |
1121 |
|
|
|
1122 |
|
|
public E set(int index, E element) { |
1123 |
dl |
1.42 |
ReentrantLock lock = l.lock; |
1124 |
|
|
lock.lock(); |
1125 |
|
|
try { |
1126 |
tim |
1.1 |
rangeCheck(index); |
1127 |
|
|
checkForComodification(); |
1128 |
dl |
1.40 |
E x = l.set(index + offset, element); |
1129 |
|
|
expectedArray = l.getArray(); |
1130 |
tim |
1.1 |
return x; |
1131 |
dl |
1.42 |
} finally { |
1132 |
|
|
lock.unlock(); |
1133 |
tim |
1.1 |
} |
1134 |
|
|
} |
1135 |
|
|
|
1136 |
|
|
public E get(int index) { |
1137 |
dl |
1.42 |
ReentrantLock lock = l.lock; |
1138 |
|
|
lock.lock(); |
1139 |
|
|
try { |
1140 |
tim |
1.1 |
rangeCheck(index); |
1141 |
|
|
checkForComodification(); |
1142 |
dl |
1.40 |
return l.get(index + offset); |
1143 |
dl |
1.42 |
} finally { |
1144 |
|
|
lock.unlock(); |
1145 |
tim |
1.1 |
} |
1146 |
|
|
} |
1147 |
|
|
|
1148 |
|
|
public int size() { |
1149 |
dl |
1.42 |
ReentrantLock lock = l.lock; |
1150 |
|
|
lock.lock(); |
1151 |
|
|
try { |
1152 |
tim |
1.1 |
checkForComodification(); |
1153 |
|
|
return size; |
1154 |
dl |
1.42 |
} finally { |
1155 |
|
|
lock.unlock(); |
1156 |
tim |
1.1 |
} |
1157 |
|
|
} |
1158 |
|
|
|
1159 |
|
|
public void add(int index, E element) { |
1160 |
dl |
1.42 |
ReentrantLock lock = l.lock; |
1161 |
|
|
lock.lock(); |
1162 |
|
|
try { |
1163 |
tim |
1.1 |
checkForComodification(); |
1164 |
|
|
if (index<0 || index>size) |
1165 |
|
|
throw new IndexOutOfBoundsException(); |
1166 |
dl |
1.40 |
l.add(index + offset, element); |
1167 |
|
|
expectedArray = l.getArray(); |
1168 |
tim |
1.1 |
size++; |
1169 |
dl |
1.42 |
} finally { |
1170 |
|
|
lock.unlock(); |
1171 |
tim |
1.1 |
} |
1172 |
|
|
} |
1173 |
|
|
|
1174 |
dl |
1.13 |
public void clear() { |
1175 |
dl |
1.42 |
ReentrantLock lock = l.lock; |
1176 |
|
|
lock.lock(); |
1177 |
|
|
try { |
1178 |
dl |
1.13 |
checkForComodification(); |
1179 |
|
|
l.removeRange(offset, offset+size); |
1180 |
dl |
1.40 |
expectedArray = l.getArray(); |
1181 |
dl |
1.13 |
size = 0; |
1182 |
dl |
1.42 |
} finally { |
1183 |
|
|
lock.unlock(); |
1184 |
dl |
1.13 |
} |
1185 |
|
|
} |
1186 |
|
|
|
1187 |
tim |
1.1 |
public E remove(int index) { |
1188 |
dl |
1.42 |
ReentrantLock lock = l.lock; |
1189 |
|
|
lock.lock(); |
1190 |
|
|
try { |
1191 |
tim |
1.1 |
rangeCheck(index); |
1192 |
|
|
checkForComodification(); |
1193 |
dl |
1.40 |
E result = l.remove(index + offset); |
1194 |
|
|
expectedArray = l.getArray(); |
1195 |
tim |
1.1 |
size--; |
1196 |
|
|
return result; |
1197 |
dl |
1.42 |
} finally { |
1198 |
|
|
lock.unlock(); |
1199 |
tim |
1.1 |
} |
1200 |
|
|
} |
1201 |
|
|
|
1202 |
|
|
public Iterator<E> iterator() { |
1203 |
dl |
1.42 |
ReentrantLock lock = l.lock; |
1204 |
|
|
lock.lock(); |
1205 |
|
|
try { |
1206 |
tim |
1.1 |
checkForComodification(); |
1207 |
tim |
1.8 |
return new COWSubListIterator<E>(l, 0, offset, size); |
1208 |
dl |
1.42 |
} finally { |
1209 |
|
|
lock.unlock(); |
1210 |
tim |
1.1 |
} |
1211 |
|
|
} |
1212 |
|
|
|
1213 |
|
|
public ListIterator<E> listIterator(final int index) { |
1214 |
dl |
1.42 |
ReentrantLock lock = l.lock; |
1215 |
|
|
lock.lock(); |
1216 |
|
|
try { |
1217 |
tim |
1.1 |
checkForComodification(); |
1218 |
|
|
if (index<0 || index>size) |
1219 |
dl |
1.40 |
throw new IndexOutOfBoundsException("Index: "+index+ |
1220 |
|
|
", Size: "+size); |
1221 |
tim |
1.8 |
return new COWSubListIterator<E>(l, index, offset, size); |
1222 |
dl |
1.42 |
} finally { |
1223 |
|
|
lock.unlock(); |
1224 |
tim |
1.1 |
} |
1225 |
|
|
} |
1226 |
|
|
|
1227 |
tim |
1.7 |
public List<E> subList(int fromIndex, int toIndex) { |
1228 |
dl |
1.42 |
ReentrantLock lock = l.lock; |
1229 |
|
|
lock.lock(); |
1230 |
|
|
try { |
1231 |
tim |
1.7 |
checkForComodification(); |
1232 |
|
|
if (fromIndex<0 || toIndex>size) |
1233 |
|
|
throw new IndexOutOfBoundsException(); |
1234 |
dl |
1.41 |
return new COWSubList<E>(l, fromIndex + offset, |
1235 |
dl |
1.40 |
toIndex + offset); |
1236 |
dl |
1.42 |
} finally { |
1237 |
|
|
lock.unlock(); |
1238 |
tim |
1.1 |
} |
1239 |
tim |
1.7 |
} |
1240 |
tim |
1.1 |
|
1241 |
tim |
1.7 |
} |
1242 |
tim |
1.1 |
|
1243 |
|
|
|
1244 |
tim |
1.7 |
private static class COWSubListIterator<E> implements ListIterator<E> { |
1245 |
|
|
private final ListIterator<E> i; |
1246 |
|
|
private final int index; |
1247 |
|
|
private final int offset; |
1248 |
|
|
private final int size; |
1249 |
dl |
1.41 |
private COWSubListIterator(List<E> l, int index, int offset, |
1250 |
dl |
1.40 |
int size) { |
1251 |
tim |
1.7 |
this.index = index; |
1252 |
|
|
this.offset = offset; |
1253 |
|
|
this.size = size; |
1254 |
dl |
1.40 |
i = l.listIterator(index + offset); |
1255 |
tim |
1.7 |
} |
1256 |
tim |
1.1 |
|
1257 |
tim |
1.7 |
public boolean hasNext() { |
1258 |
|
|
return nextIndex() < size; |
1259 |
|
|
} |
1260 |
tim |
1.1 |
|
1261 |
tim |
1.7 |
public E next() { |
1262 |
|
|
if (hasNext()) |
1263 |
|
|
return i.next(); |
1264 |
|
|
else |
1265 |
|
|
throw new NoSuchElementException(); |
1266 |
|
|
} |
1267 |
tim |
1.1 |
|
1268 |
tim |
1.7 |
public boolean hasPrevious() { |
1269 |
|
|
return previousIndex() >= 0; |
1270 |
|
|
} |
1271 |
tim |
1.1 |
|
1272 |
tim |
1.7 |
public E previous() { |
1273 |
|
|
if (hasPrevious()) |
1274 |
|
|
return i.previous(); |
1275 |
|
|
else |
1276 |
|
|
throw new NoSuchElementException(); |
1277 |
|
|
} |
1278 |
tim |
1.1 |
|
1279 |
tim |
1.7 |
public int nextIndex() { |
1280 |
|
|
return i.nextIndex() - offset; |
1281 |
|
|
} |
1282 |
tim |
1.1 |
|
1283 |
tim |
1.7 |
public int previousIndex() { |
1284 |
|
|
return i.previousIndex() - offset; |
1285 |
tim |
1.1 |
} |
1286 |
|
|
|
1287 |
tim |
1.7 |
public void remove() { |
1288 |
|
|
throw new UnsupportedOperationException(); |
1289 |
|
|
} |
1290 |
tim |
1.1 |
|
1291 |
jsr166 |
1.33 |
public void set(E e) { |
1292 |
tim |
1.7 |
throw new UnsupportedOperationException(); |
1293 |
tim |
1.1 |
} |
1294 |
|
|
|
1295 |
jsr166 |
1.33 |
public void add(E e) { |
1296 |
tim |
1.7 |
throw new UnsupportedOperationException(); |
1297 |
|
|
} |
1298 |
tim |
1.1 |
} |
1299 |
|
|
|
1300 |
dl |
1.42 |
// Support for resetting lock while deserializing |
1301 |
|
|
private static final Unsafe unsafe = Unsafe.getUnsafe(); |
1302 |
|
|
private static final long lockOffset; |
1303 |
|
|
static { |
1304 |
|
|
try { |
1305 |
|
|
lockOffset = unsafe.objectFieldOffset |
1306 |
|
|
(CopyOnWriteArrayList.class.getDeclaredField("lock")); |
1307 |
|
|
} catch (Exception ex) { throw new Error(ex); } |
1308 |
|
|
} |
1309 |
|
|
private void resetLock() { |
1310 |
|
|
unsafe.putObjectVolatile(this, lockOffset, new ReentrantLock()); |
1311 |
|
|
} |
1312 |
|
|
|
1313 |
|
|
|
1314 |
dl |
1.40 |
// Temporary emulations of anticipated new j.u.Arrays functions |
1315 |
|
|
|
1316 |
dl |
1.42 |
private static <T,U> T[] copyOfRange(U[] original, int from, int to, |
1317 |
dl |
1.40 |
Class<? extends T[]> newType) { |
1318 |
|
|
int newLength = to - from; |
1319 |
|
|
if (newLength < 0) |
1320 |
|
|
throw new IllegalArgumentException(from + " > " + to); |
1321 |
|
|
T[] copy = (T[]) java.lang.reflect.Array.newInstance |
1322 |
|
|
(newType.getComponentType(), newLength); |
1323 |
|
|
System.arraycopy(original, from, copy, 0, |
1324 |
|
|
Math.min(original.length - from, newLength)); |
1325 |
|
|
return copy; |
1326 |
|
|
} |
1327 |
dl |
1.41 |
|
1328 |
dl |
1.42 |
private static <T,U> T[] copyOf(U[] original, int newLength, |
1329 |
dl |
1.40 |
Class<? extends T[]> newType) { |
1330 |
|
|
T[] copy = (T[]) java.lang.reflect.Array.newInstance |
1331 |
|
|
(newType.getComponentType(), newLength); |
1332 |
|
|
System.arraycopy(original, 0, copy, 0, |
1333 |
|
|
Math.min(original.length, newLength)); |
1334 |
|
|
return copy; |
1335 |
|
|
} |
1336 |
|
|
|
1337 |
dl |
1.42 |
private static <T> T[] copyOf(T[] original, int newLength) { |
1338 |
|
|
return (T[]) copyOf(original, newLength, original.getClass()); |
1339 |
dl |
1.40 |
} |
1340 |
tim |
1.1 |
} |