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My first initial commit with all of mine experimental changes.

Dmitry Kabak (userdima committed 13 years ago

Commit d37b88d1 parent 3f5b46618352 files · +2598093 −-8690Browse files

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1+/*
2+ * Copyright (c) 2007, Oracle and/or its affiliates. All rights reserved.
3+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4+ *
5+ * This code is free software; you can redistribute it and/or modify it
6+ * under the terms of the GNU General Public License version 2 only, as
7+ * published by the Free Software Foundation. Oracle designates this
8+ * particular file as subject to the "Classpath" exception as provided
9+ * by Oracle in the LICENSE file that accompanied this code.
10+ *
11+ * This code is distributed in the hope that it will be useful, but WITHOUT
12+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14+ * version 2 for more details (a copy is included in the LICENSE file that
15+ * accompanied this code).
16+ *
17+ * You should have received a copy of the GNU General Public License version
18+ * 2 along with this work; if not, write to the Free Software Foundation,
19+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20+ *
21+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22+ * or visit www.oracle.com if you need additional information or have any
23+ * questions.
24+ */
25+
26+package sun.awt.util;
27+
28+import java.util.AbstractList;
29+import java.util.Arrays;
30+import java.util.Collection;
31+import java.util.ConcurrentModificationException;
32+import java.util.List;
33+import java.util.RandomAccess;
34+
35+/**
36+ * Resizable-array implementation of the <tt>List</tt> interface. Implements
37+ * all optional list operations, and permits all elements, including
38+ * <tt>null</tt>. In addition to implementing the <tt>List</tt> interface,
39+ * this class provides methods to manipulate the size of the array that is
40+ * used internally to store the list. (This class is roughly equivalent to
41+ * <tt>Vector</tt>, except that it is unsynchronized.)<p>
42+ *
43+ * The <tt>size</tt>, <tt>isEmpty</tt>, <tt>get</tt>, <tt>set</tt>,
44+ * <tt>iterator</tt>, and <tt>listIterator</tt> operations run in constant
45+ * time. The <tt>add</tt> operation runs in <i>amortized constant time</i>,
46+ * that is, adding n elements requires O(n) time. All of the other operations
47+ * run in linear time (roughly speaking). The constant factor is low compared
48+ * to that for the <tt>LinkedList</tt> implementation.<p>
49+ *
50+ * Each <tt>IdentityArrayList</tt> instance has a <i>capacity</i>. The capacity is
51+ * the size of the array used to store the elements in the list. It is always
52+ * at least as large as the list size. As elements are added to an IdentityArrayList,
53+ * its capacity grows automatically. The details of the growth policy are not
54+ * specified beyond the fact that adding an element has constant amortized
55+ * time cost.<p>
56+ *
57+ * An application can increase the capacity of an <tt>IdentityArrayList</tt> instance
58+ * before adding a large number of elements using the <tt>ensureCapacity</tt>
59+ * operation. This may reduce the amount of incremental reallocation.
60+ *
61+ * <p><strong>Note that this implementation is not synchronized.</strong>
62+ * If multiple threads access an <tt>IdentityArrayList</tt> instance concurrently,
63+ * and at least one of the threads modifies the list structurally, it
64+ * <i>must</i> be synchronized externally. (A structural modification is
65+ * any operation that adds or deletes one or more elements, or explicitly
66+ * resizes the backing array; merely setting the value of an element is not
67+ * a structural modification.) This is typically accomplished by
68+ * synchronizing on some object that naturally encapsulates the list.
69+ *
70+ * If no such object exists, the list should be "wrapped" using the
71+ * {@link Collections#synchronizedList Collections.synchronizedList}
72+ * method. This is best done at creation time, to prevent accidental
73+ * unsynchronized access to the list:<pre>
74+ * List list = Collections.synchronizedList(new IdentityArrayList(...));</pre>
75+ *
76+ * <p>The iterators returned by this class's <tt>iterator</tt> and
77+ * <tt>listIterator</tt> methods are <i>fail-fast</i>: if the list is
78+ * structurally modified at any time after the iterator is created, in any way
79+ * except through the iterator's own <tt>remove</tt> or <tt>add</tt> methods,
80+ * the iterator will throw a {@link ConcurrentModificationException}. Thus, in
81+ * the face of concurrent modification, the iterator fails quickly and cleanly,
82+ * rather than risking arbitrary, non-deterministic behavior at an undetermined
83+ * time in the future.<p>
84+ *
85+ * Note that the fail-fast behavior of an iterator cannot be guaranteed
86+ * as it is, generally speaking, impossible to make any hard guarantees in the
87+ * presence of unsynchronized concurrent modification. Fail-fast iterators
88+ * throw <tt>ConcurrentModificationException</tt> on a best-effort basis.
89+ * Therefore, it would be wrong to write a program that depended on this
90+ * exception for its correctness: <i>the fail-fast behavior of iterators
91+ * should be used only to detect bugs.</i><p>
92+ *
93+ */
94+
95+public class IdentityArrayList<E> extends AbstractList<E>
96+ implements List<E>, RandomAccess
97+{
98+
99+ /**
100+ * The array buffer into which the elements of the IdentityArrayList are stored.
101+ * The capacity of the IdentityArrayList is the length of this array buffer.
102+ */
103+ private transient Object[] elementData;
104+
105+ /**
106+ * The size of the IdentityArrayList (the number of elements it contains).
107+ *
108+ * @serial
109+ */
110+ private int size;
111+
112+ /**
113+ * Constructs an empty list with the specified initial capacity.
114+ *
115+ * @param initialCapacity the initial capacity of the list
116+ * @exception IllegalArgumentException if the specified initial capacity
117+ * is negative
118+ */
119+ public IdentityArrayList(int initialCapacity) {
120+ super();
121+ if (initialCapacity < 0)
122+ throw new IllegalArgumentException("Illegal Capacity: "+
123+ initialCapacity);
124+ this.elementData = new Object[initialCapacity];
125+ }
126+
127+ /**
128+ * Constructs an empty list with an initial capacity of ten.
129+ */
130+ public IdentityArrayList() {
131+ this(10);
132+ }
133+
134+ /**
135+ * Constructs a list containing the elements of the specified
136+ * collection, in the order they are returned by the collection's
137+ * iterator.
138+ *
139+ * @param c the collection whose elements are to be placed into this list
140+ * @throws NullPointerException if the specified collection is null
141+ */
142+ public IdentityArrayList(Collection<? extends E> c) {
143+ elementData = c.toArray();
144+ size = elementData.length;
145+ // c.toArray might (incorrectly) not return Object[] (see 6260652)
146+ if (elementData.getClass() != Object[].class)
147+ elementData = Arrays.copyOf(elementData, size, Object[].class);
148+ }
149+
150+ /**
151+ * Trims the capacity of this <tt>IdentityArrayList</tt> instance to be the
152+ * list's current size. An application can use this operation to minimize
153+ * the storage of an <tt>IdentityArrayList</tt> instance.
154+ */
155+ public void trimToSize() {
156+ modCount++;
157+ int oldCapacity = elementData.length;
158+ if (size < oldCapacity) {
159+ elementData = Arrays.copyOf(elementData, size);
160+ }
161+ }
162+
163+ /**
164+ * Increases the capacity of this <tt>IdentityArrayList</tt> instance, if
165+ * necessary, to ensure that it can hold at least the number of elements
166+ * specified by the minimum capacity argument.
167+ *
168+ * @param minCapacity the desired minimum capacity
169+ */
170+ public void ensureCapacity(int minCapacity) {
171+ modCount++;
172+ int oldCapacity = elementData.length;
173+ if (minCapacity > oldCapacity) {
174+ Object oldData[] = elementData;
175+ int newCapacity = (oldCapacity * 3)/2 + 1;
176+ if (newCapacity < minCapacity)
177+ newCapacity = minCapacity;
178+ // minCapacity is usually close to size, so this is a win:
179+ elementData = Arrays.copyOf(elementData, newCapacity);
180+ }
181+ }
182+
183+ /**
184+ * Returns the number of elements in this list.
185+ *
186+ * @return the number of elements in this list
187+ */
188+ public int size() {
189+ return size;
190+ }
191+
192+ /**
193+ * Returns <tt>true</tt> if this list contains no elements.
194+ *
195+ * @return <tt>true</tt> if this list contains no elements
196+ */
197+ public boolean isEmpty() {
198+ return size == 0;
199+ }
200+
201+ /**
202+ * Returns <tt>true</tt> if this list contains the specified element.
203+ * More formally, returns <tt>true</tt> if and only if this list contains
204+ * at least one element <tt>e</tt> such that
205+ * <tt>(o==null&nbsp;?&nbsp;e==null&nbsp;:&nbsp;o == e)</tt>.
206+ *
207+ * @param o element whose presence in this list is to be tested
208+ * @return <tt>true</tt> if this list contains the specified element
209+ */
210+ public boolean contains(Object o) {
211+ return indexOf(o) >= 0;
212+ }
213+
214+ /**
215+ * Returns the index of the first occurrence of the specified element
216+ * in this list, or -1 if this list does not contain the element.
217+ * More formally, returns the lowest index <tt>i</tt> such that
218+ * <tt>(o==null&nbsp;?&nbsp;get(i)==null&nbsp;:&nbsp;o == get(i))</tt>,
219+ * or -1 if there is no such index.
220+ */
221+ public int indexOf(Object o) {
222+ for (int i = 0; i < size; i++) {
223+ if (o == elementData[i]) {
224+ return i;
225+ }
226+ }
227+ return -1;
228+ }
229+
230+ /**
231+ * Returns the index of the last occurrence of the specified element
232+ * in this list, or -1 if this list does not contain the element.
233+ * More formally, returns the highest index <tt>i</tt> such that
234+ * <tt>(o==null&nbsp;?&nbsp;get(i)==null&nbsp;:&nbsp;o == get(i))</tt>,
235+ * or -1 if there is no such index.
236+ */
237+ public int lastIndexOf(Object o) {
238+ for (int i = size-1; i >= 0; i--) {
239+ if (o == elementData[i]) {
240+ return i;
241+ }
242+ }
243+ return -1;
244+ }
245+
246+ /**
247+ * Returns an array containing all of the elements in this list
248+ * in proper sequence (from first to last element).
249+ *
250+ * <p>The returned array will be "safe" in that no references to it are
251+ * maintained by this list. (In other words, this method must allocate
252+ * a new array). The caller is thus free to modify the returned array.
253+ *
254+ * <p>This method acts as bridge between array-based and collection-based
255+ * APIs.
256+ *
257+ * @return an array containing all of the elements in this list in
258+ * proper sequence
259+ */
260+ public Object[] toArray() {
261+ return Arrays.copyOf(elementData, size);
262+ }
263+
264+ /**
265+ * Returns an array containing all of the elements in this list in proper
266+ * sequence (from first to last element); the runtime type of the returned
267+ * array is that of the specified array. If the list fits in the
268+ * specified array, it is returned therein. Otherwise, a new array is
269+ * allocated with the runtime type of the specified array and the size of
270+ * this list.
271+ *
272+ * <p>If the list fits in the specified array with room to spare
273+ * (i.e., the array has more elements than the list), the element in
274+ * the array immediately following the end of the collection is set to
275+ * <tt>null</tt>. (This is useful in determining the length of the
276+ * list <i>only</i> if the caller knows that the list does not contain
277+ * any null elements.)
278+ *
279+ * @param a the array into which the elements of the list are to
280+ * be stored, if it is big enough; otherwise, a new array of the
281+ * same runtime type is allocated for this purpose.
282+ * @return an array containing the elements of the list
283+ * @throws ArrayStoreException if the runtime type of the specified array
284+ * is not a supertype of the runtime type of every element in
285+ * this list
286+ * @throws NullPointerException if the specified array is null
287+ */
288+ public <T> T[] toArray(T[] a) {
289+ if (a.length < size)
290+ // Make a new array of a's runtime type, but my contents:
291+ return (T[]) Arrays.copyOf(elementData, size, a.getClass());
292+ System.arraycopy(elementData, 0, a, 0, size);
293+ if (a.length > size)
294+ a[size] = null;
295+ return a;
296+ }
297+
298+ // Positional Access Operations
299+
300+ /**
301+ * Returns the element at the specified position in this list.
302+ *
303+ * @param index index of the element to return
304+ * @return the element at the specified position in this list
305+ * @throws IndexOutOfBoundsException {@inheritDoc}
306+ */
307+ public E get(int index) {
308+ rangeCheck(index);
309+
310+ return (E) elementData[index];
311+ }
312+
313+ /**
314+ * Replaces the element at the specified position in this list with
315+ * the specified element.
316+ *
317+ * @param index index of the element to replace
318+ * @param element element to be stored at the specified position
319+ * @return the element previously at the specified position
320+ * @throws IndexOutOfBoundsException {@inheritDoc}
321+ */
322+ public E set(int index, E element) {
323+ rangeCheck(index);
324+
325+ E oldValue = (E) elementData[index];
326+ elementData[index] = element;
327+ return oldValue;
328+ }
329+
330+ /**
331+ * Appends the specified element to the end of this list.
332+ *
333+ * @param e element to be appended to this list
334+ * @return <tt>true</tt> (as specified by {@link Collection#add})
335+ */
336+ public boolean add(E e) {
337+ ensureCapacity(size + 1); // Increments modCount!!
338+ elementData[size++] = e;
339+ return true;
340+ }
341+
342+ /**
343+ * Inserts the specified element at the specified position in this
344+ * list. Shifts the element currently at that position (if any) and
345+ * any subsequent elements to the right (adds one to their indices).
346+ *
347+ * @param index index at which the specified element is to be inserted
348+ * @param element element to be inserted
349+ * @throws IndexOutOfBoundsException {@inheritDoc}
350+ */
351+ public void add(int index, E element) {
352+ rangeCheckForAdd(index);
353+
354+ ensureCapacity(size+1); // Increments modCount!!
355+ System.arraycopy(elementData, index, elementData, index + 1,
356+ size - index);
357+ elementData[index] = element;
358+ size++;
359+ }
360+
361+ /**
362+ * Removes the element at the specified position in this list.
363+ * Shifts any subsequent elements to the left (subtracts one from their
364+ * indices).
365+ *
366+ * @param index the index of the element to be removed
367+ * @return the element that was removed from the list
368+ * @throws IndexOutOfBoundsException {@inheritDoc}
369+ */
370+ public E remove(int index) {
371+ rangeCheck(index);
372+
373+ modCount++;
374+ E oldValue = (E) elementData[index];
375+
376+ int numMoved = size - index - 1;
377+ if (numMoved > 0)
378+ System.arraycopy(elementData, index+1, elementData, index,
379+ numMoved);
380+ elementData[--size] = null; // Let gc do its work
381+
382+ return oldValue;
383+ }
384+
385+ /**
386+ * Removes the first occurrence of the specified element from this list,
387+ * if it is present. If the list does not contain the element, it is
388+ * unchanged. More formally, removes the element with the lowest index
389+ * <tt>i</tt> such that
390+ * <tt>(o==null&nbsp;?&nbsp;get(i)==null&nbsp;:&nbsp;o == get(i))</tt>
391+ * (if such an element exists). Returns <tt>true</tt> if this list
392+ * contained the specified element (or equivalently, if this list
393+ * changed as a result of the call).
394+ *
395+ * @param o element to be removed from this list, if present
396+ * @return <tt>true</tt> if this list contained the specified element
397+ */
398+ public boolean remove(Object o) {
399+ for (int index = 0; index < size; index++) {
400+ if (o == elementData[index]) {
401+ fastRemove(index);
402+ return true;
403+ }
404+ }
405+ return false;
406+ }
407+
408+ /*
409+ * Private remove method that skips bounds checking and does not
410+ * return the value removed.
411+ */
412+ private void fastRemove(int index) {
413+ modCount++;
414+ int numMoved = size - index - 1;
415+ if (numMoved > 0)
416+ System.arraycopy(elementData, index+1, elementData, index,
417+ numMoved);
418+ elementData[--size] = null; // Let gc do its work
419+ }
420+
421+ /**
422+ * Removes all of the elements from this list. The list will
423+ * be empty after this call returns.
424+ */
425+ public void clear() {
426+ modCount++;
427+
428+ // Let gc do its work
429+ for (int i = 0; i < size; i++)
430+ elementData[i] = null;
431+
432+ size = 0;
433+ }
434+
435+ /**
436+ * Appends all of the elements in the specified collection to the end of
437+ * this list, in the order that they are returned by the
438+ * specified collection's Iterator. The behavior of this operation is
439+ * undefined if the specified collection is modified while the operation
440+ * is in progress. (This implies that the behavior of this call is
441+ * undefined if the specified collection is this list, and this
442+ * list is nonempty.)
443+ *
444+ * @param c collection containing elements to be added to this list
445+ * @return <tt>true</tt> if this list changed as a result of the call
446+ * @throws NullPointerException if the specified collection is null
447+ */
448+ public boolean addAll(Collection<? extends E> c) {
449+ Object[] a = c.toArray();
450+ int numNew = a.length;
451+ ensureCapacity(size + numNew); // Increments modCount
452+ System.arraycopy(a, 0, elementData, size, numNew);
453+ size += numNew;
454+ return numNew != 0;
455+ }
456+
457+ /**
458+ * Inserts all of the elements in the specified collection into this
459+ * list, starting at the specified position. Shifts the element
460+ * currently at that position (if any) and any subsequent elements to
461+ * the right (increases their indices). The new elements will appear
462+ * in the list in the order that they are returned by the
463+ * specified collection's iterator.
464+ *
465+ * @param index index at which to insert the first element from the
466+ * specified collection
467+ * @param c collection containing elements to be added to this list
468+ * @return <tt>true</tt> if this list changed as a result of the call
469+ * @throws IndexOutOfBoundsException {@inheritDoc}
470+ * @throws NullPointerException if the specified collection is null
471+ */
472+ public boolean addAll(int index, Collection<? extends E> c) {
473+ rangeCheckForAdd(index);
474+
475+ Object[] a = c.toArray();
476+ int numNew = a.length;
477+ ensureCapacity(size + numNew); // Increments modCount
478+
479+ int numMoved = size - index;
480+ if (numMoved > 0) {
481+ System.arraycopy(elementData, index, elementData, index + numNew, numMoved);
482+ }
483+
484+ System.arraycopy(a, 0, elementData, index, numNew);
485+ size += numNew;
486+ return numNew != 0;
487+ }
488+
489+ /**
490+ * Removes from this list all of the elements whose index is between
491+ * <tt>fromIndex</tt>, inclusive, and <tt>toIndex</tt>, exclusive.
492+ * Shifts any succeeding elements to the left (reduces their index).
493+ * This call shortens the list by <tt>(toIndex - fromIndex)</tt> elements.
494+ * (If <tt>toIndex==fromIndex</tt>, this operation has no effect.)
495+ *
496+ * @param fromIndex index of first element to be removed
497+ * @param toIndex index after last element to be removed
498+ * @throws IndexOutOfBoundsException if fromIndex or toIndex out of
499+ * range (fromIndex &lt; 0 || fromIndex &gt;= size() || toIndex
500+ * &gt; size() || toIndex &lt; fromIndex)
501+ */
502+ protected void removeRange(int fromIndex, int toIndex) {
503+ modCount++;
504+ int numMoved = size - toIndex;
505+ System.arraycopy(elementData, toIndex, elementData, fromIndex,
506+ numMoved);
507+
508+ // Let gc do its work
509+ int newSize = size - (toIndex-fromIndex);
510+ while (size != newSize)
511+ elementData[--size] = null;
512+ }
513+
514+ /**
515+ * Checks if the given index is in range. If not, throws an appropriate
516+ * runtime exception. This method does *not* check if the index is
517+ * negative: It is always used immediately prior to an array access,
518+ * which throws an ArrayIndexOutOfBoundsException if index is negative.
519+ */
520+ private void rangeCheck(int index) {
521+ if (index >= size)
522+ throw new IndexOutOfBoundsException(outOfBoundsMsg(index));
523+ }
524+
525+ /**
526+ * A version of rangeCheck used by add and addAll.
527+ */
528+ private void rangeCheckForAdd(int index) {
529+ if (index > size || index < 0)
530+ throw new IndexOutOfBoundsException(outOfBoundsMsg(index));
531+ }
532+
533+ /**
534+ * Constructs an IndexOutOfBoundsException detail message.
535+ * Of the many possible refactorings of the error handling code,
536+ * this "outlining" performs best with both server and client VMs.
537+ */
538+ private String outOfBoundsMsg(int index) {
539+ return "Index: "+index+", Size: "+size;
540+ }
541+}