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1.2 |
/* |
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* Written by Doug Lea with assistance from members of JCP JSR-166 |
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1.3 |
* Expert Group. Adapted and released under explicit permission |
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* from JDK1.2 ArrayList.java which carries the following copyright: |
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* |
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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. |
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* |
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* This software is the confidential and proprietary information |
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* of Sun Microsystems, Inc. ("Confidential Information"). You |
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* shall not disclose such Confidential Information and shall use |
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* it only in accordance with the terms of the license agreement |
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* you entered into with Sun. |
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dl |
1.2 |
*/ |
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tim |
1.1 |
package java.util.concurrent; |
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import java.util.*; |
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/** |
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* CopyOnWriteArrayList is a variant of java.util.ArrayList in which all |
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* mutative operations (add, set, and so on) are implemented by making |
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* a fresh copy of the underlying array. <p> |
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* |
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* This is ordinarily too costly, but it becomes attractive when |
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* traversal operations vastly overwhelm mutations, and, especially, |
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* when you cannot or don't want to synchronize traversals, yet need |
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* to preclude interference among concurrent threads. The iterator |
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* method uses a reference to the state of the array at the point that |
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* the iterator was created. This array never changes during the |
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* lifetime of the iterator, so interference is impossible. (The |
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* iterator will not traverse elements added or changed since the |
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* iterator was created, but usually this is a desirable feature.) |
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* <p> |
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* |
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* Because of the copy-on-write policy, some one-by-one mutative |
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* operations in the java.util.Arrays and java.util.Collections |
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dl |
1.2 |
* classes are so time/space intensive as to never be worth calling. |
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* <p> |
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1.1 |
* |
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* Due to their strict read-only nature, element-changing operations |
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* on iterators (remove, set, and add) are not supported. These are |
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* the only methods throwing UnsupportedOperationException. <p> |
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**/ |
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public class CopyOnWriteArrayList<E> |
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implements List<E>, RandomAccess, Cloneable, java.io.Serializable { |
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/** |
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* The held array. Directly access only within synchronized |
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* methods |
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*/ |
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1.2 |
private volatile transient E[] array_; |
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1.1 |
|
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/** |
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* Accessor to the array intended to be called from |
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* within unsynchronized read-only methods |
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**/ |
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1.2 |
private E[] array() { return array_; } |
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1.1 |
|
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/** |
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* Constructs an empty list |
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* |
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*/ |
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public CopyOnWriteArrayList() { |
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array_ = new E[0]; |
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} |
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/** |
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* Constructs an list containing the elements of the specified |
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* Collection, in the order they are returned by the Collection's |
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* iterator. |
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*/ |
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public CopyOnWriteArrayList(Collection<E> c) { |
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array_ = new E[c.size()]; |
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Iterator<E> i = c.iterator(); |
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int size = 0; |
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while (i.hasNext()) |
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array_[size++] = i.next(); |
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} |
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/** |
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* Create a new CopyOnWriteArrayList holding a copy of given array |
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* @param toCopyIn the array. A copy of this array is used as the |
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* internal array. |
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**/ |
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public CopyOnWriteArrayList(E[] toCopyIn) { |
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copyIn(toCopyIn, 0, toCopyIn.length); |
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} |
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/** |
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* Replace the held array with a copy of the <code>n</code> |
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* elements of the provided array, starting at position <code>first</code>. |
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* To copy an entire array, call with arguments (array, 0, array.length). |
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* @param toCopyIn the array. A copy of the indicated elements of |
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* this array is used as the |
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* internal array. |
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* @param first The index of first position of the array to |
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* start copying from. |
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* @param n the number of elements to copy. This will be the new size of |
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* the list. |
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**/ |
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private synchronized void copyIn(E[] toCopyIn, int first, int n) { |
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array_ = new E[n]; |
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System.arraycopy(toCopyIn, first, array_, 0, n); |
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} |
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/** |
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* Returns the number of components in this list. |
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* |
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* @return the number of components in this list. |
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*/ |
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public int size() { |
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return array().length; |
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} |
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/** |
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* Tests if this list has no components. |
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* |
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* @return <code>true</code> if this list has no components; |
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* <code>false</code> otherwise. |
121 |
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*/ |
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public boolean isEmpty() { |
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return size() == 0; |
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} |
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/** |
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* Returns true if this list contains the specified element. |
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* |
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* @param o element whose presence in this List is to be tested. |
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*/ |
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public boolean contains(Object elem) { |
132 |
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E[] elementData = array(); |
133 |
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int len = elementData.length; |
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return indexOf(elem, elementData, len) >= 0; |
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} |
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/** |
138 |
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* Searches for the first occurence of the given argument, testing |
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* for equality using the <code>equals</code> method. |
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* |
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* @param elem an object. |
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* @return the index of the first occurrence of the argument in this |
143 |
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* list; returns <code>-1</code> if the object is not found. |
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* @see Object#equals(Object) |
145 |
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*/ |
146 |
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public int indexOf(Object elem) { |
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E[] elementData = array(); |
148 |
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int len = elementData.length; |
149 |
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return indexOf(elem, elementData, len); |
150 |
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} |
151 |
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152 |
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153 |
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/** |
154 |
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* static version allows repeated call without needed |
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* to grab lock for array each time |
156 |
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**/ |
157 |
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private static int indexOf(Object elem, Object[] elementData, int len) { |
158 |
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if (elem == null) { |
159 |
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for (int i = 0; i < len; i++) |
160 |
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if (elementData[i]==null) |
161 |
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return i; |
162 |
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} else { |
163 |
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for (int i = 0; i < len; i++) |
164 |
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if (elem.equals(elementData[i])) |
165 |
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return i; |
166 |
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} |
167 |
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return -1; |
168 |
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} |
169 |
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170 |
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/** |
171 |
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* Searches for the first occurence of the given argument, beginning |
172 |
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* the search at <code>index</code>, and testing for equality using |
173 |
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* the <code>equals</code> method. |
174 |
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* |
175 |
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* @param elem an object. |
176 |
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* @param index the index to start searching from. |
177 |
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* @return the index of the first occurrence of the object argument in |
178 |
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* this List at position <code>index</code> or later in the |
179 |
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* List; returns <code>-1</code> if the object is not found. |
180 |
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* @see Object#equals(Object) |
181 |
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*/ |
182 |
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public int indexOf(E elem, int index) { |
183 |
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E[] elementData = array(); |
184 |
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int elementCount = elementData.length; |
185 |
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186 |
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if (elem == null) { |
187 |
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for (int i = index ; i < elementCount ; i++) |
188 |
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if (elementData[i]==null) |
189 |
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return i; |
190 |
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} else { |
191 |
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for (int i = index ; i < elementCount ; i++) |
192 |
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if (elem.equals(elementData[i])) |
193 |
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return i; |
194 |
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} |
195 |
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return -1; |
196 |
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} |
197 |
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198 |
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/** |
199 |
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* Returns the index of the last occurrence of the specified object in |
200 |
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* this list. |
201 |
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* |
202 |
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* @param elem the desired component. |
203 |
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* @return the index of the last occurrence of the specified object in |
204 |
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* this list; returns -1 if the object is not found. |
205 |
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*/ |
206 |
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public int lastIndexOf(Object elem) { |
207 |
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E[] elementData = array(); |
208 |
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int len = elementData.length; |
209 |
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return lastIndexOf(elem, elementData, len); |
210 |
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} |
211 |
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212 |
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private static int lastIndexOf(Object elem, Object[] elementData, int len) { |
213 |
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if (elem == null) { |
214 |
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for (int i = len-1; i >= 0; i--) |
215 |
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if (elementData[i]==null) |
216 |
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return i; |
217 |
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} else { |
218 |
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for (int i = len-1; i >= 0; i--) |
219 |
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if (elem.equals(elementData[i])) |
220 |
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return i; |
221 |
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} |
222 |
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return -1; |
223 |
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} |
224 |
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225 |
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/** |
226 |
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* Searches backwards for the specified object, starting from the |
227 |
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* specified index, and returns an index to it. |
228 |
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* |
229 |
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* @param elem the desired component. |
230 |
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* @param index the index to start searching from. |
231 |
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* @return the index of the last occurrence of the specified object in this |
232 |
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* List at position less than index in the List; |
233 |
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* -1 if the object is not found. |
234 |
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*/ |
235 |
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public int lastIndexOf(E elem, int index) { |
236 |
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// needed in order to compile on 1.2b3 |
237 |
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E[] elementData = array(); |
238 |
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if (elem == null) { |
239 |
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for (int i = index; i >= 0; i--) |
240 |
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if (elementData[i]==null) |
241 |
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return i; |
242 |
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} else { |
243 |
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for (int i = index; i >= 0; i--) |
244 |
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if (elem.equals(elementData[i])) |
245 |
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return i; |
246 |
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} |
247 |
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return -1; |
248 |
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} |
249 |
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250 |
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/** |
251 |
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* Returns a shallow copy of this list. (The elements themselves |
252 |
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* are not copied.) |
253 |
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* |
254 |
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* @return a clone of this list. |
255 |
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*/ |
256 |
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public Object clone() { |
257 |
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try { |
258 |
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E[] elementData = array(); |
259 |
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CopyOnWriteArrayList<E> v = (CopyOnWriteArrayList)super.clone(); |
260 |
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v.array_ = new E[elementData.length]; |
261 |
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System.arraycopy(elementData, 0, v.array_, 0, elementData.length); |
262 |
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return v; |
263 |
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} catch (CloneNotSupportedException e) { |
264 |
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// this shouldn't happen, since we are Cloneable |
265 |
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throw new InternalError(); |
266 |
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} |
267 |
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} |
268 |
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269 |
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/** |
270 |
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* Returns an array containing all of the elements in this list |
271 |
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* in the correct order. |
272 |
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*/ |
273 |
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public Object[] toArray() { |
274 |
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Object[] elementData = array(); |
275 |
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Object[] result = new Object[elementData.length]; |
276 |
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System.arraycopy(elementData, 0, result, 0, elementData.length); |
277 |
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return result; |
278 |
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} |
279 |
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280 |
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/** |
281 |
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* Returns an array containing all of the elements in this list in the |
282 |
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* correct order. The runtime type of the returned array is that of the |
283 |
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* specified array. If the list fits in the specified array, it is |
284 |
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* returned therein. Otherwise, a new array is allocated with the runtime |
285 |
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* type of the specified array and the size of this list. |
286 |
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* <p> |
287 |
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* If the list fits in the specified array with room to spare |
288 |
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* (i.e., the array has more elements than the list), |
289 |
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* the element in the array immediately following the end of the |
290 |
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* collection is set to null. This is useful in determining the length |
291 |
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* of the list <em>only</em> if the caller knows that the list |
292 |
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* does not contain any null elements. |
293 |
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* |
294 |
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* @param a the array into which the elements of the list are to |
295 |
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* be stored, if it is big enough; otherwise, a new array of the |
296 |
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* same runtime type is allocated for this purpose. |
297 |
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* @return an array containing the elements of the list. |
298 |
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* @exception ArrayStoreException the runtime type of a is not a supertype |
299 |
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* of the runtime type of every element in this list. |
300 |
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*/ |
301 |
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public <T> T[] toArray(T a[]) { |
302 |
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E[] elementData = array(); |
303 |
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304 |
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if (a.length < elementData.length) |
305 |
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a = (T[]) |
306 |
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java.lang.reflect.Array.newInstance(a.getClass().getComponentType(), |
307 |
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elementData.length); |
308 |
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309 |
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System.arraycopy(elementData, 0, a, 0, elementData.length); |
310 |
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311 |
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if (a.length > elementData.length) |
312 |
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a[elementData.length] = null; |
313 |
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314 |
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return a; |
315 |
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} |
316 |
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|
317 |
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// Positional Access Operations |
318 |
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|
319 |
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/** |
320 |
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* Returns the element at the specified position in this list. |
321 |
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* |
322 |
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* @param index index of element to return. |
323 |
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* @exception IndexOutOfBoundsException index is out of range (index |
324 |
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* < 0 || index >= size()). |
325 |
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*/ |
326 |
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public E get(int index) { |
327 |
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E[] elementData = array(); |
328 |
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rangeCheck(index, elementData.length); |
329 |
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return elementData[index]; |
330 |
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} |
331 |
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|
332 |
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/** |
333 |
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* Replaces the element at the specified position in this list with |
334 |
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* the specified element. |
335 |
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* |
336 |
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* @param index index of element to replace. |
337 |
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* @param element element to be stored at the specified position. |
338 |
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* @return the element previously at the specified position. |
339 |
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* @exception IndexOutOfBoundsException index out of range |
340 |
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* (index < 0 || index >= size()). |
341 |
|
|
*/ |
342 |
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public synchronized E set(int index, E element) { |
343 |
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int len = array_.length; |
344 |
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rangeCheck(index, len); |
345 |
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E oldValue = array_[index]; |
346 |
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347 |
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boolean same = (oldValue == element || |
348 |
|
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(element != null && element.equals(oldValue))); |
349 |
|
|
if (!same) { |
350 |
|
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E[] newArray = new E[len]; |
351 |
|
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System.arraycopy(array_, 0, newArray, 0, len); |
352 |
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newArray[index] = element; |
353 |
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array_ = newArray; |
354 |
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} |
355 |
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|
return oldValue; |
356 |
|
|
} |
357 |
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|
358 |
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/** |
359 |
|
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* Appends the specified element to the end of this list. |
360 |
|
|
* |
361 |
|
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* @param element element to be appended to this list. |
362 |
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* @return true (as per the general contract of Collection.add). |
363 |
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|
*/ |
364 |
|
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public synchronized boolean add(E element) { |
365 |
|
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int len = array_.length; |
366 |
|
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E[] newArray = new E[len+1]; |
367 |
|
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System.arraycopy(array_, 0, newArray, 0, len); |
368 |
|
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newArray[len] = element; |
369 |
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array_ = newArray; |
370 |
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return true; |
371 |
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|
} |
372 |
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|
373 |
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/** |
374 |
|
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* Inserts the specified element at the specified position in this |
375 |
|
|
* list. Shifts the element currently at that position (if any) and |
376 |
|
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* any subsequent elements to the right (adds one to their indices). |
377 |
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* |
378 |
|
|
* @param index index at which the specified element is to be inserted. |
379 |
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|
* @param element element to be inserted. |
380 |
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|
* @exception IndexOutOfBoundsException index is out of range |
381 |
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|
* (index < 0 || index > size()). |
382 |
|
|
*/ |
383 |
|
|
public synchronized void add(int index, E element) { |
384 |
|
|
int len = array_.length; |
385 |
|
|
if (index > len || index < 0) |
386 |
|
|
throw new IndexOutOfBoundsException("Index: "+index+", Size: "+len); |
387 |
|
|
|
388 |
|
|
E[] newArray = new E[len+1]; |
389 |
|
|
System.arraycopy(array_, 0, newArray, 0, index); |
390 |
|
|
newArray[index] = element; |
391 |
|
|
System.arraycopy(array_, index, newArray, index+1, len - index); |
392 |
|
|
array_ = newArray; |
393 |
|
|
} |
394 |
|
|
|
395 |
|
|
/** |
396 |
|
|
* Removes the element at the specified position in this list. |
397 |
|
|
* Shifts any subsequent elements to the left (subtracts one from their |
398 |
|
|
* indices). Returns the element that was removed from the list. |
399 |
|
|
* |
400 |
|
|
* @exception IndexOutOfBoundsException index out of range (index |
401 |
|
|
* < 0 || index >= size()). |
402 |
|
|
* @param index the index of the element to removed. |
403 |
|
|
*/ |
404 |
|
|
public synchronized E remove(int index) { |
405 |
|
|
int len = array_.length; |
406 |
|
|
rangeCheck(index, len); |
407 |
|
|
E oldValue = array_[index]; |
408 |
|
|
E[] newArray = new E[len-1]; |
409 |
|
|
System.arraycopy(array_, 0, newArray, 0, index); |
410 |
|
|
int numMoved = len - index - 1; |
411 |
|
|
if (numMoved > 0) |
412 |
|
|
System.arraycopy(array_, index+1, newArray, index, numMoved); |
413 |
|
|
array_ = newArray; |
414 |
|
|
return oldValue; |
415 |
|
|
} |
416 |
|
|
|
417 |
|
|
/** |
418 |
|
|
* Removes a single instance of the specified element from this Collection, |
419 |
|
|
* if it is present (optional operation). More formally, removes an |
420 |
|
|
* element <code>e</code> such that <code>(o==null ? e==null : |
421 |
|
|
* o.equals(e))</code>, if the Collection contains one or more such |
422 |
|
|
* elements. Returns true if the Collection contained the specified |
423 |
|
|
* element (or equivalently, if the Collection changed as a result of the |
424 |
|
|
* call). |
425 |
|
|
* |
426 |
|
|
* @param element element to be removed from this Collection, if present. |
427 |
|
|
* @return true if the Collection changed as a result of the call. |
428 |
|
|
*/ |
429 |
|
|
public synchronized boolean remove(Object element) { |
430 |
|
|
int len = array_.length; |
431 |
|
|
if (len == 0) return false; |
432 |
|
|
|
433 |
|
|
// Copy while searching for element to remove |
434 |
|
|
// This wins in the normal case of element being present |
435 |
|
|
|
436 |
|
|
int newlen = len-1; |
437 |
|
|
E[] newArray = new E[newlen]; |
438 |
|
|
|
439 |
|
|
for (int i = 0; i < newlen; ++i) { |
440 |
|
|
if (element == array_[i] || |
441 |
|
|
(element != null && element.equals(array_[i]))) { |
442 |
|
|
// found one; copy remaining and exit |
443 |
|
|
for (int k = i + 1; k < len; ++k) newArray[k-1] = array_[k]; |
444 |
|
|
array_ = newArray; |
445 |
|
|
return true; |
446 |
|
|
} |
447 |
|
|
else |
448 |
|
|
newArray[i] = array_[i]; |
449 |
|
|
} |
450 |
|
|
// special handling for last cell |
451 |
|
|
|
452 |
|
|
if (element == array_[newlen] || |
453 |
|
|
(element != null && element.equals(array_[newlen]))) { |
454 |
|
|
array_ = newArray; |
455 |
|
|
return true; |
456 |
|
|
} |
457 |
|
|
else |
458 |
|
|
return false; // throw away copy |
459 |
|
|
|
460 |
|
|
} |
461 |
|
|
|
462 |
|
|
|
463 |
|
|
/** |
464 |
|
|
* Removes from this List all of the elements whose index is between |
465 |
|
|
* fromIndex, inclusive and toIndex, exclusive. Shifts any succeeding |
466 |
|
|
* elements to the left (reduces their index). |
467 |
|
|
* This call shortens the List by (toIndex - fromIndex) elements. (If |
468 |
|
|
* toIndex==fromIndex, this operation has no effect.) |
469 |
|
|
* |
470 |
|
|
* @param fromIndex index of first element to be removed. |
471 |
|
|
* @param fromIndex index after last element to be removed. |
472 |
|
|
* @exception IndexOutOfBoundsException fromIndex or toIndex out of |
473 |
|
|
* range (fromIndex < 0 || fromIndex >= size() || toIndex |
474 |
|
|
* > size() || toIndex < fromIndex). |
475 |
|
|
*/ |
476 |
|
|
private synchronized void removeRange(int fromIndex, int toIndex) { |
477 |
|
|
int len = array_.length; |
478 |
|
|
|
479 |
|
|
if (fromIndex < 0 || fromIndex >= len || |
480 |
|
|
toIndex > len || toIndex < fromIndex) |
481 |
|
|
throw new IndexOutOfBoundsException(); |
482 |
|
|
|
483 |
|
|
int numMoved = len - toIndex; |
484 |
|
|
int newlen = len - (toIndex-fromIndex); |
485 |
|
|
E[] newArray = new E[newlen]; |
486 |
|
|
System.arraycopy(array_, 0, newArray, 0, fromIndex); |
487 |
|
|
System.arraycopy(array_, toIndex, newArray, fromIndex, numMoved); |
488 |
|
|
array_ = newArray; |
489 |
|
|
} |
490 |
|
|
|
491 |
|
|
|
492 |
|
|
/** |
493 |
|
|
* Append the element if not present. |
494 |
|
|
* This operation can be used to obtain Set semantics |
495 |
|
|
* for lists. |
496 |
|
|
* @param element element to be added to this Collection, if absent. |
497 |
|
|
* @return true if added |
498 |
|
|
**/ |
499 |
|
|
public synchronized boolean addIfAbsent(E element) { |
500 |
|
|
// Copy while checking if already present. |
501 |
|
|
// This wins in the most common case where it is not present |
502 |
|
|
int len = array_.length; |
503 |
|
|
E[] newArray = new E[len + 1]; |
504 |
|
|
for (int i = 0; i < len; ++i) { |
505 |
|
|
if (element == array_[i] || |
506 |
|
|
(element != null && element.equals(array_[i]))) |
507 |
|
|
return false; // exit, throwing away copy |
508 |
|
|
else |
509 |
|
|
newArray[i] = array_[i]; |
510 |
|
|
} |
511 |
|
|
newArray[len] = element; |
512 |
|
|
array_ = newArray; |
513 |
|
|
return true; |
514 |
|
|
} |
515 |
|
|
|
516 |
|
|
/** |
517 |
|
|
* Returns true if this Collection contains all of the elements in the |
518 |
|
|
* specified Collection. |
519 |
|
|
* <p> |
520 |
|
|
* This implementation iterates over the specified Collection, checking |
521 |
|
|
* each element returned by the Iterator in turn to see if it's |
522 |
|
|
* contained in this Collection. If all elements are so contained |
523 |
|
|
* true is returned, otherwise false. |
524 |
|
|
* |
525 |
|
|
*/ |
526 |
|
|
public <T> boolean containsAll(Collection<T> c) { |
527 |
|
|
E[] elementData = array(); |
528 |
|
|
int len = elementData.length; |
529 |
|
|
Iterator<T> e = c.iterator(); |
530 |
|
|
while (e.hasNext()) |
531 |
|
|
if(indexOf(e.next(), elementData, len) < 0) |
532 |
|
|
return false; |
533 |
|
|
|
534 |
|
|
return true; |
535 |
|
|
} |
536 |
|
|
|
537 |
|
|
|
538 |
|
|
/** |
539 |
|
|
* Removes from this Collection all of its elements that are contained in |
540 |
|
|
* the specified Collection. This is a particularly expensive operation |
541 |
|
|
* in this class because of the need for an internal temporary array. |
542 |
|
|
* <p> |
543 |
|
|
* |
544 |
|
|
* @return true if this Collection changed as a result of the call. |
545 |
|
|
*/ |
546 |
|
|
public synchronized <T> boolean removeAll(Collection<T> c) { |
547 |
|
|
E[] elementData = array_; |
548 |
|
|
int len = elementData.length; |
549 |
|
|
if (len == 0) return false; |
550 |
|
|
|
551 |
|
|
// temp array holds those elements we know we want to keep |
552 |
|
|
E[] temp = new E[len]; |
553 |
|
|
int newlen = 0; |
554 |
|
|
for (int i = 0; i < len; ++i) { |
555 |
|
|
E element = elementData[i]; |
556 |
|
|
if (!c.contains(element)) { |
557 |
|
|
temp[newlen++] = element; |
558 |
|
|
} |
559 |
|
|
} |
560 |
|
|
|
561 |
|
|
if (newlen == len) return false; |
562 |
|
|
|
563 |
|
|
// copy temp as new array |
564 |
|
|
E[] newArray = new E[newlen]; |
565 |
|
|
System.arraycopy(temp, 0, newArray, 0, newlen); |
566 |
|
|
array_ = newArray; |
567 |
|
|
return true; |
568 |
|
|
} |
569 |
|
|
|
570 |
|
|
/** |
571 |
|
|
* Retains only the elements in this Collection that are contained in the |
572 |
|
|
* specified Collection (optional operation). In other words, removes from |
573 |
|
|
* this Collection all of its elements that are not contained in the |
574 |
|
|
* specified Collection. |
575 |
|
|
* @return true if this Collection changed as a result of the call. |
576 |
|
|
*/ |
577 |
|
|
public synchronized <T> boolean retainAll(Collection<T> c) { |
578 |
|
|
E[] elementData = array_; |
579 |
|
|
int len = elementData.length; |
580 |
|
|
if (len == 0) return false; |
581 |
|
|
|
582 |
|
|
E[] temp = new E[len]; |
583 |
|
|
int newlen = 0; |
584 |
|
|
for (int i = 0; i < len; ++i) { |
585 |
|
|
E element = elementData[i]; |
586 |
|
|
if (c.contains(element)) { |
587 |
|
|
temp[newlen++] = element; |
588 |
|
|
} |
589 |
|
|
} |
590 |
|
|
|
591 |
|
|
if (newlen == len) return false; |
592 |
|
|
|
593 |
|
|
E[] newArray = new E[newlen]; |
594 |
|
|
System.arraycopy(temp, 0, newArray, 0, newlen); |
595 |
|
|
array_ = newArray; |
596 |
|
|
return true; |
597 |
|
|
} |
598 |
|
|
|
599 |
|
|
/** |
600 |
|
|
* Appends all of the elements in the specified Collection that |
601 |
|
|
* are not already contained in this list, to the end of |
602 |
|
|
* this list, in the order that they are returned by the |
603 |
|
|
* specified Collection's Iterator. |
604 |
|
|
* |
605 |
|
|
* @param c elements to be added into this list. |
606 |
|
|
* @return the number of elements added |
607 |
|
|
*/ |
608 |
|
|
public synchronized <T extends E> int addAllAbsent(Collection<T> c) { |
609 |
|
|
int numNew = c.size(); |
610 |
|
|
if (numNew == 0) return 0; |
611 |
|
|
|
612 |
|
|
E[] elementData = array_; |
613 |
|
|
int len = elementData.length; |
614 |
|
|
|
615 |
|
|
E[] temp = new E[numNew]; |
616 |
|
|
int added = 0; |
617 |
|
|
Iterator<T> e = c.iterator(); |
618 |
|
|
while (e.hasNext()) { |
619 |
|
|
E element = e.next(); |
620 |
|
|
if (indexOf(element, elementData, len) < 0) { |
621 |
|
|
if (indexOf(element, temp, added) < 0) { |
622 |
|
|
temp[added++] = element; |
623 |
|
|
} |
624 |
|
|
} |
625 |
|
|
} |
626 |
|
|
|
627 |
|
|
if (added == 0) return 0; |
628 |
|
|
|
629 |
|
|
E[] newArray = new E[len+added]; |
630 |
|
|
System.arraycopy(elementData, 0, newArray, 0, len); |
631 |
|
|
System.arraycopy(temp, 0, newArray, len, added); |
632 |
|
|
array_ = newArray; |
633 |
|
|
return added; |
634 |
|
|
} |
635 |
|
|
|
636 |
|
|
/** |
637 |
|
|
* Removes all of the elements from this list. |
638 |
|
|
* |
639 |
|
|
*/ |
640 |
|
|
public synchronized void clear() { |
641 |
|
|
array_ = new E[0]; |
642 |
|
|
} |
643 |
|
|
|
644 |
|
|
/** |
645 |
|
|
* Appends all of the elements in the specified Collection to the end of |
646 |
|
|
* this list, in the order that they are returned by the |
647 |
|
|
* specified Collection's Iterator. |
648 |
|
|
* |
649 |
|
|
* @param c elements to be inserted into this list. |
650 |
|
|
*/ |
651 |
|
|
public synchronized <T extends E> boolean addAll(Collection<T> c) { |
652 |
|
|
int numNew = c.size(); |
653 |
|
|
if (numNew == 0) return false; |
654 |
|
|
|
655 |
|
|
int len = array_.length; |
656 |
|
|
E[] newArray = new E[len+numNew]; |
657 |
|
|
System.arraycopy(array_, 0, newArray, 0, len); |
658 |
|
|
Iterator<T> e = c.iterator(); |
659 |
|
|
for (int i=0; i<numNew; i++) |
660 |
|
|
newArray[len++] = e.next(); |
661 |
|
|
array_ = newArray; |
662 |
|
|
|
663 |
|
|
return true; |
664 |
|
|
} |
665 |
|
|
|
666 |
|
|
/** |
667 |
|
|
* Inserts all of the elements in the specified Collection into this |
668 |
|
|
* list, starting at the specified position. Shifts the element |
669 |
|
|
* currently at that position (if any) and any subsequent elements to |
670 |
|
|
* the right (increases their indices). The new elements will appear |
671 |
|
|
* in the list in the order that they are returned by the |
672 |
|
|
* specified Collection's iterator. |
673 |
|
|
* |
674 |
|
|
* @param index index at which to insert first element |
675 |
|
|
* from the specified collection. |
676 |
|
|
* @param c elements to be inserted into this list. |
677 |
|
|
* @exception IndexOutOfBoundsException index out of range (index |
678 |
|
|
* < 0 || index > size()). |
679 |
|
|
*/ |
680 |
|
|
public synchronized <T extends E> boolean addAll(int index, Collection<T> c) { |
681 |
|
|
int len = array_.length; |
682 |
|
|
if (index > len || index < 0) |
683 |
|
|
throw new IndexOutOfBoundsException("Index: "+index+", Size: "+len); |
684 |
|
|
|
685 |
|
|
int numNew = c.size(); |
686 |
|
|
if (numNew == 0) return false; |
687 |
|
|
|
688 |
|
|
E[] newArray = new E[len+numNew]; |
689 |
|
|
System.arraycopy(array_, 0, newArray, 0, len); |
690 |
|
|
int numMoved = len - index; |
691 |
|
|
if (numMoved > 0) |
692 |
|
|
System.arraycopy(array_, index, newArray, index + numNew, numMoved); |
693 |
|
|
Iterator<T> e = c.iterator(); |
694 |
|
|
for (int i=0; i<numNew; i++) |
695 |
|
|
newArray[index++] = e.next(); |
696 |
|
|
array_ = newArray; |
697 |
|
|
|
698 |
|
|
return true; |
699 |
|
|
} |
700 |
|
|
|
701 |
|
|
/** |
702 |
|
|
* Check if the given index is in range. If not, throw an appropriate |
703 |
|
|
* runtime exception. |
704 |
|
|
*/ |
705 |
|
|
private void rangeCheck(int index, int length) { |
706 |
|
|
if (index >= length || index < 0) |
707 |
|
|
throw new IndexOutOfBoundsException("Index: "+index+", Size: "+ length); |
708 |
|
|
} |
709 |
|
|
|
710 |
|
|
/** |
711 |
|
|
* Save the state of the list to a stream (i.e., serialize it). |
712 |
|
|
* |
713 |
|
|
* @serialData The length of the array backing the list is emitted |
714 |
|
|
* (int), followed by all of its elements (each an Object) |
715 |
|
|
* in the proper order. |
716 |
|
|
*/ |
717 |
|
|
private void writeObject(java.io.ObjectOutputStream s) |
718 |
|
|
throws java.io.IOException{ |
719 |
|
|
|
720 |
|
|
// Write out element count, and any hidden stuff |
721 |
|
|
s.defaultWriteObject(); |
722 |
|
|
|
723 |
|
|
E[] elementData = array(); |
724 |
|
|
// Write out array length |
725 |
|
|
s.writeInt(elementData.length); |
726 |
|
|
|
727 |
|
|
// Write out all elements in the proper order. |
728 |
|
|
for (int i=0; i<elementData.length; i++) |
729 |
|
|
s.writeObject(elementData[i]); |
730 |
|
|
} |
731 |
|
|
|
732 |
|
|
/** |
733 |
|
|
* Reconstitute the list from a stream (i.e., deserialize it). |
734 |
|
|
*/ |
735 |
|
|
private synchronized void readObject(java.io.ObjectInputStream s) |
736 |
|
|
throws java.io.IOException, ClassNotFoundException { |
737 |
|
|
|
738 |
|
|
// Read in size, and any hidden stuff |
739 |
|
|
s.defaultReadObject(); |
740 |
|
|
|
741 |
|
|
// Read in array length and allocate array |
742 |
|
|
int arrayLength = s.readInt(); |
743 |
|
|
E[] elementData = new E[arrayLength]; |
744 |
|
|
|
745 |
|
|
// Read in all elements in the proper order. |
746 |
|
|
for (int i=0; i<elementData.length; i++) |
747 |
|
|
elementData[i] = (E) s.readObject(); |
748 |
|
|
array_ = elementData; |
749 |
|
|
} |
750 |
|
|
|
751 |
|
|
/** |
752 |
|
|
* Returns a string representation of this Collection, containing |
753 |
|
|
* the String representation of each element. |
754 |
|
|
*/ |
755 |
|
|
public String toString() { |
756 |
|
|
StringBuffer buf = new StringBuffer(); |
757 |
|
|
Iterator e = iterator(); |
758 |
|
|
buf.append("["); |
759 |
|
|
int maxIndex = size() - 1; |
760 |
|
|
for (int i = 0; i <= maxIndex; i++) { |
761 |
|
|
buf.append(String.valueOf(e.next())); |
762 |
|
|
if (i < maxIndex) |
763 |
|
|
buf.append(", "); |
764 |
|
|
} |
765 |
|
|
buf.append("]"); |
766 |
|
|
return buf.toString(); |
767 |
|
|
} |
768 |
|
|
|
769 |
|
|
|
770 |
|
|
/** |
771 |
|
|
* Compares the specified Object with this List for equality. Returns true |
772 |
|
|
* if and only if the specified Object is also a List, both Lists have the |
773 |
|
|
* same size, and all corresponding pairs of elements in the two Lists are |
774 |
|
|
* <em>equal</em>. (Two elements <code>e1</code> and <code>e2</code> are |
775 |
|
|
* <em>equal</em> if <code>(e1==null ? e2==null : e1.equals(e2))</code>.) |
776 |
|
|
* In other words, two Lists are defined to be equal if they contain the |
777 |
|
|
* same elements in the same order. |
778 |
|
|
* <p> |
779 |
|
|
* This implementation first checks if the specified object is this |
780 |
|
|
* List. If so, it returns true; if not, it checks if the specified |
781 |
|
|
* object is a List. If not, it returns false; if so, it iterates over |
782 |
|
|
* both lists, comparing corresponding pairs of elements. If any |
783 |
|
|
* comparison returns false, this method returns false. If either |
784 |
|
|
* Iterator runs out of elements before before the other it returns false |
785 |
|
|
* (as the Lists are of unequal length); otherwise it returns true when |
786 |
|
|
* the iterations complete. |
787 |
|
|
* |
788 |
|
|
* @param o the Object to be compared for equality with this List. |
789 |
|
|
* @return true if the specified Object is equal to this List. |
790 |
|
|
*/ |
791 |
|
|
public boolean equals(Object o) { |
792 |
|
|
if (o == this) |
793 |
|
|
return true; |
794 |
|
|
if (!(o instanceof List)) |
795 |
|
|
return false; |
796 |
|
|
|
797 |
|
|
List<E> l2 = (List)(o); |
798 |
|
|
if (size() != l2.size()) |
799 |
|
|
return false; |
800 |
|
|
|
801 |
|
|
ListIterator<E> e1 = listIterator(); |
802 |
|
|
ListIterator<E> e2 = l2.listIterator(); |
803 |
|
|
while(e1.hasNext()) { |
804 |
|
|
E o1 = e1.next(); |
805 |
|
|
E o2 = e2.next(); |
806 |
|
|
if (!(o1==null ? o2==null : o1.equals(o2))) |
807 |
|
|
return false; |
808 |
|
|
} |
809 |
|
|
return true; |
810 |
|
|
} |
811 |
|
|
|
812 |
|
|
/** |
813 |
|
|
* Returns the hash code value for this List. |
814 |
|
|
* <p> |
815 |
|
|
* This implementation uses exactly the code that is used to define |
816 |
|
|
* the List hash function in the documentation for List.hashCode. |
817 |
|
|
*/ |
818 |
|
|
public int hashCode() { |
819 |
|
|
int hashCode = 1; |
820 |
|
|
Iterator<E> i = iterator(); |
821 |
|
|
while (i.hasNext()) { |
822 |
|
|
E obj = i.next(); |
823 |
|
|
hashCode = 31*hashCode + (obj==null ? 0 : obj.hashCode()); |
824 |
|
|
} |
825 |
|
|
return hashCode; |
826 |
|
|
} |
827 |
|
|
|
828 |
|
|
/** |
829 |
|
|
* Returns an Iterator over the elements contained in this collection. |
830 |
|
|
* The iterator provides a snapshot of the state of the list |
831 |
|
|
* when the iterator was constructed. No synchronization is |
832 |
|
|
* needed while traversing the iterator. The iterator does |
833 |
|
|
* <em>NOT</em> support the <code>remove</code> method. |
834 |
|
|
*/ |
835 |
|
|
public Iterator<E> iterator() { |
836 |
|
|
return new COWIterator<E>(array(), 0); |
837 |
|
|
} |
838 |
|
|
|
839 |
|
|
/** |
840 |
|
|
* Returns an Iterator of the elements in this List (in proper sequence). |
841 |
|
|
* The iterator provides a snapshot of the state of the list |
842 |
|
|
* when the iterator was constructed. No synchronization is |
843 |
|
|
* needed while traversing the iterator. The iterator does |
844 |
|
|
* <em>NOT</em> support the <code>remove</code>, <code>set</code>, |
845 |
|
|
* or <code>add</code> methods. |
846 |
|
|
* |
847 |
|
|
*/ |
848 |
|
|
public ListIterator<E> listIterator() { |
849 |
|
|
return new COWIterator<E>(array(), 0); |
850 |
|
|
} |
851 |
|
|
|
852 |
|
|
/** |
853 |
|
|
* Returns a ListIterator of the elements in this List (in proper |
854 |
|
|
* sequence), starting at the specified position in the List. The |
855 |
|
|
* specified index indicates the first element that would be returned by |
856 |
|
|
* an initial call to nextElement. An initial call to previousElement |
857 |
|
|
* would return the element with the specified index minus one. |
858 |
|
|
* The ListIterator returned by this implementation will throw |
859 |
|
|
* an UnsupportedOperationException in its remove, set and |
860 |
|
|
* add methods. |
861 |
|
|
* |
862 |
|
|
* @param index index of first element to be returned from the |
863 |
|
|
* ListIterator (by a call to getNext). |
864 |
|
|
* @exception IndexOutOfBoundsException index is out of range |
865 |
|
|
* (index < 0 || index > size()). |
866 |
|
|
*/ |
867 |
|
|
public ListIterator<E> listIterator(final int index) { |
868 |
|
|
E[] elementData = array(); |
869 |
|
|
int len = elementData.length; |
870 |
|
|
if (index<0 || index>len) |
871 |
|
|
throw new IndexOutOfBoundsException("Index: "+index); |
872 |
|
|
|
873 |
|
|
return new COWIterator<E>(array(), index); |
874 |
|
|
} |
875 |
|
|
|
876 |
|
|
private static class COWIterator<E> implements ListIterator<E> { |
877 |
|
|
|
878 |
|
|
/** Snapshot of the array **/ |
879 |
|
|
private final E[] array; |
880 |
|
|
|
881 |
|
|
/** |
882 |
|
|
* Index of element to be returned by subsequent call to next. |
883 |
|
|
*/ |
884 |
|
|
private int cursor; |
885 |
|
|
|
886 |
|
|
private COWIterator(E[] elementArray, int initialCursor) { |
887 |
|
|
array = elementArray; |
888 |
|
|
cursor = initialCursor; |
889 |
|
|
} |
890 |
|
|
|
891 |
|
|
public boolean hasNext() { |
892 |
|
|
return cursor < array.length; |
893 |
|
|
} |
894 |
|
|
|
895 |
|
|
public boolean hasPrevious() { |
896 |
|
|
return cursor > 0; |
897 |
|
|
} |
898 |
|
|
|
899 |
|
|
public E next() { |
900 |
|
|
try { |
901 |
|
|
return array[cursor++]; |
902 |
|
|
} |
903 |
|
|
catch (IndexOutOfBoundsException ex) { |
904 |
|
|
throw new NoSuchElementException(); |
905 |
|
|
} |
906 |
|
|
} |
907 |
|
|
|
908 |
|
|
public E previous() { |
909 |
|
|
try { |
910 |
|
|
return array[--cursor]; |
911 |
|
|
} catch(IndexOutOfBoundsException e) { |
912 |
|
|
throw new NoSuchElementException(); |
913 |
|
|
} |
914 |
|
|
} |
915 |
|
|
|
916 |
|
|
public int nextIndex() { |
917 |
|
|
return cursor; |
918 |
|
|
} |
919 |
|
|
|
920 |
|
|
public int previousIndex() { |
921 |
|
|
return cursor-1; |
922 |
|
|
} |
923 |
|
|
|
924 |
|
|
/** |
925 |
|
|
* Not supported. Always throws UnsupportedOperationException. |
926 |
|
|
* @exception UnsupportedOperationException remove is not supported |
927 |
|
|
* by this Iterator. |
928 |
|
|
*/ |
929 |
|
|
|
930 |
|
|
public void remove() { |
931 |
|
|
throw new UnsupportedOperationException(); |
932 |
|
|
} |
933 |
|
|
|
934 |
|
|
/** |
935 |
|
|
* Not supported. Always throws UnsupportedOperationException. |
936 |
|
|
* @exception UnsupportedOperationException set is not supported |
937 |
|
|
* by this Iterator. |
938 |
|
|
*/ |
939 |
|
|
public void set(E o) { |
940 |
|
|
throw new UnsupportedOperationException(); |
941 |
|
|
} |
942 |
|
|
|
943 |
|
|
/** |
944 |
|
|
* Not supported. Always throws UnsupportedOperationException. |
945 |
|
|
* @exception UnsupportedOperationException add is not supported |
946 |
|
|
* by this Iterator. |
947 |
|
|
*/ |
948 |
|
|
public void add(E o) { |
949 |
|
|
throw new UnsupportedOperationException(); |
950 |
|
|
} |
951 |
|
|
} |
952 |
|
|
|
953 |
|
|
|
954 |
|
|
/** |
955 |
|
|
* Returns a view of the portion of this List between fromIndex, |
956 |
|
|
* inclusive, and toIndex, exclusive. The returned List is backed by this |
957 |
|
|
* List, so changes in the returned List are reflected in this List, and |
958 |
|
|
* vice-versa. While mutative operations are supported, they are |
959 |
|
|
* probably not very useful for CopyOnWriteArrays. |
960 |
|
|
* </p> |
961 |
|
|
* The semantics of the List returned by this method become undefined if |
962 |
|
|
* the backing list (i.e., this List) is <i>structurally modified</i> in |
963 |
|
|
* any way other than via the returned List. (Structural modifications are |
964 |
|
|
* those that change the size of the List, or otherwise perturb it in such |
965 |
|
|
* a fashion that iterations in progress may yield incorrect results.) |
966 |
|
|
* |
967 |
|
|
* @param fromIndex low endpoint (inclusive) of the subList. |
968 |
|
|
* @param toKey high endpoint (exclusive) of the subList. |
969 |
|
|
* @return a view of the specified range within this List. |
970 |
|
|
* @exception IndexOutOfBoundsException Illegal endpoint index value |
971 |
|
|
* (fromIndex < 0 || toIndex > size || fromIndex > toIndex). |
972 |
|
|
*/ |
973 |
|
|
public synchronized List<E> subList(int fromIndex, int toIndex) { |
974 |
|
|
// synchronized since sublist ctor depends on it. |
975 |
|
|
int len = array_.length; |
976 |
|
|
if (fromIndex<0 || toIndex>len || fromIndex>toIndex) |
977 |
|
|
throw new IndexOutOfBoundsException(); |
978 |
|
|
return new COWSubList<E>(this, fromIndex, toIndex); |
979 |
|
|
} |
980 |
|
|
|
981 |
|
|
private static class COWSubList<E> extends AbstractList<E> { |
982 |
|
|
|
983 |
|
|
/* |
984 |
dl |
1.2 |
This class extends AbstractList merely for convenience, to |
985 |
|
|
avoid having to define addAll, etc. This doesn't hurt, but |
986 |
|
|
is wasteful. This class does not need or use modCount |
987 |
|
|
mechanics in AbstractList, but does need to check for |
988 |
|
|
concurrent modification using similar mechanics. On each |
989 |
|
|
operation, the array that we expect the backing list to use |
990 |
|
|
is checked and updated. Since we do this for all of the |
991 |
|
|
base operations invoked by those defined in AbstractList, |
992 |
|
|
all is well. While inefficient, this is not worth |
993 |
|
|
improving. The kinds of list operations inherited from |
994 |
|
|
AbstractList are are already so slow on COW sublists that |
995 |
|
|
adding a bit more space/time doesn't seem even noticeable. |
996 |
tim |
1.1 |
*/ |
997 |
|
|
|
998 |
|
|
private final CopyOnWriteArrayList<E> l; |
999 |
|
|
private final int offset; |
1000 |
|
|
private int size; |
1001 |
|
|
private E[] expectedArray; |
1002 |
|
|
|
1003 |
|
|
private COWSubList(CopyOnWriteArrayList<E> list, |
1004 |
|
|
int fromIndex, int toIndex) { |
1005 |
|
|
l = list; |
1006 |
|
|
expectedArray = l.array(); |
1007 |
|
|
offset = fromIndex; |
1008 |
|
|
size = toIndex - fromIndex; |
1009 |
|
|
} |
1010 |
|
|
|
1011 |
|
|
// only call this holding l's lock |
1012 |
|
|
private void checkForComodification() { |
1013 |
|
|
if (l.array_ != expectedArray) |
1014 |
|
|
throw new ConcurrentModificationException(); |
1015 |
|
|
} |
1016 |
|
|
|
1017 |
|
|
// only call this holding l's lock |
1018 |
|
|
private void rangeCheck(int index) { |
1019 |
|
|
if (index<0 || index>=size) |
1020 |
|
|
throw new IndexOutOfBoundsException("Index: "+index+ ",Size: "+size); |
1021 |
|
|
} |
1022 |
|
|
|
1023 |
|
|
|
1024 |
|
|
public E set(int index, E element) { |
1025 |
|
|
synchronized(l) { |
1026 |
|
|
rangeCheck(index); |
1027 |
|
|
checkForComodification(); |
1028 |
|
|
E x = l.set(index+offset, element); |
1029 |
|
|
expectedArray = l.array_; |
1030 |
|
|
return x; |
1031 |
|
|
} |
1032 |
|
|
} |
1033 |
|
|
|
1034 |
|
|
public E get(int index) { |
1035 |
|
|
synchronized(l) { |
1036 |
|
|
rangeCheck(index); |
1037 |
|
|
checkForComodification(); |
1038 |
|
|
return l.get(index+offset); |
1039 |
|
|
} |
1040 |
|
|
} |
1041 |
|
|
|
1042 |
|
|
public int size() { |
1043 |
|
|
synchronized(l) { |
1044 |
|
|
checkForComodification(); |
1045 |
|
|
return size; |
1046 |
|
|
} |
1047 |
|
|
} |
1048 |
|
|
|
1049 |
|
|
public void add(int index, E element) { |
1050 |
|
|
synchronized(l) { |
1051 |
|
|
checkForComodification(); |
1052 |
|
|
if (index<0 || index>size) |
1053 |
|
|
throw new IndexOutOfBoundsException(); |
1054 |
|
|
l.add(index+offset, element); |
1055 |
|
|
expectedArray = l.array_; |
1056 |
|
|
size++; |
1057 |
|
|
} |
1058 |
|
|
} |
1059 |
|
|
|
1060 |
|
|
public E remove(int index) { |
1061 |
|
|
synchronized(l) { |
1062 |
|
|
rangeCheck(index); |
1063 |
|
|
checkForComodification(); |
1064 |
|
|
E result = l.remove(index+offset); |
1065 |
|
|
expectedArray = l.array_; |
1066 |
|
|
size--; |
1067 |
|
|
return result; |
1068 |
|
|
} |
1069 |
|
|
} |
1070 |
|
|
|
1071 |
|
|
public Iterator<E> iterator() { |
1072 |
|
|
synchronized(l) { |
1073 |
|
|
checkForComodification(); |
1074 |
|
|
return new COWSubListIterator(0); |
1075 |
|
|
} |
1076 |
|
|
} |
1077 |
|
|
|
1078 |
|
|
public ListIterator<E> listIterator(final int index) { |
1079 |
|
|
synchronized(l) { |
1080 |
|
|
checkForComodification(); |
1081 |
|
|
if (index<0 || index>size) |
1082 |
|
|
throw new IndexOutOfBoundsException("Index: "+index+", Size: "+size); |
1083 |
|
|
return new COWSubListIterator(index); |
1084 |
|
|
} |
1085 |
|
|
} |
1086 |
|
|
|
1087 |
|
|
private class COWSubListIterator implements ListIterator<E> { |
1088 |
|
|
private final ListIterator<E> i; |
1089 |
|
|
private final int index; |
1090 |
|
|
private COWSubListIterator(int index) { |
1091 |
|
|
this.index = index; |
1092 |
|
|
i = l.listIterator(index+offset); |
1093 |
|
|
} |
1094 |
|
|
|
1095 |
|
|
public boolean hasNext() { |
1096 |
|
|
return nextIndex() < size; |
1097 |
|
|
} |
1098 |
|
|
|
1099 |
|
|
public E next() { |
1100 |
|
|
if (hasNext()) |
1101 |
|
|
return i.next(); |
1102 |
|
|
else |
1103 |
|
|
throw new NoSuchElementException(); |
1104 |
|
|
} |
1105 |
|
|
|
1106 |
|
|
public boolean hasPrevious() { |
1107 |
|
|
return previousIndex() >= 0; |
1108 |
|
|
} |
1109 |
|
|
|
1110 |
|
|
public E previous() { |
1111 |
|
|
if (hasPrevious()) |
1112 |
|
|
return i.previous(); |
1113 |
|
|
else |
1114 |
|
|
throw new NoSuchElementException(); |
1115 |
|
|
} |
1116 |
|
|
|
1117 |
|
|
public int nextIndex() { |
1118 |
|
|
return i.nextIndex() - offset; |
1119 |
|
|
} |
1120 |
|
|
|
1121 |
|
|
public int previousIndex() { |
1122 |
|
|
return i.previousIndex() - offset; |
1123 |
|
|
} |
1124 |
|
|
|
1125 |
|
|
public void remove() { |
1126 |
|
|
throw new UnsupportedOperationException(); |
1127 |
|
|
} |
1128 |
|
|
|
1129 |
|
|
public void set(E o) { |
1130 |
|
|
throw new UnsupportedOperationException(); |
1131 |
|
|
} |
1132 |
|
|
|
1133 |
|
|
public void add(E o) { |
1134 |
|
|
throw new UnsupportedOperationException(); |
1135 |
|
|
} |
1136 |
|
|
} |
1137 |
|
|
|
1138 |
|
|
|
1139 |
|
|
public List<E> subList(int fromIndex, int toIndex) { |
1140 |
|
|
synchronized(l) { |
1141 |
|
|
checkForComodification(); |
1142 |
|
|
if (fromIndex<0 || toIndex>size) |
1143 |
|
|
throw new IndexOutOfBoundsException(); |
1144 |
|
|
return new COWSubList<E>(l, fromIndex+offset, toIndex+offset); |
1145 |
|
|
} |
1146 |
|
|
} |
1147 |
|
|
|
1148 |
|
|
} |
1149 |
|
|
|
1150 |
|
|
} |