1 /*
2 * Copyright (c) 2003, 2012, 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 java.util;
27
28 /**
29 * Private implementation class for EnumSet, for "jumbo" enum types
30 * (i.e., those with more than 64 elements).
31 *
32 * @author Josh Bloch
33 * @since 1.5
34 * @serial exclude
35 */
36 class JumboEnumSet<E extends Enum<E>> extends EnumSet<E> {
37 private static final long serialVersionUID = 334349849919042784L;
38
39 /**
40 * Bit vector representation of this set. The ith bit of the jth
41 * element of this array represents the presence of universe[64*j +i]
42 * in this set.
43 */
44 private long[] elements;
45
46 // Redundant - maintained for performance
47 private int size = 0;
48
49 JumboEnumSet(Class<E>elementType, Enum<?>[] universe) {
50 super(elementType, universe);
51 elements = new long[(universe.length + 63) >>> 6];
52 }
53
54 void addRange(E from, E to) {
55 int fromIndex = from.ordinal() >>> 6;
56 int toIndex = to.ordinal() >>> 6;
57
58 if (fromIndex == toIndex) {
59 elements[fromIndex] = (-1L >>> (from.ordinal() - to.ordinal() - 1))
60 << from.ordinal();
61 } else {
62 elements[fromIndex] = (-1L << from.ordinal());
63 for (int i = fromIndex + 1; i < toIndex; i++)
64 elements[i] = -1;
65 elements[toIndex] = -1L >>> (63 - to.ordinal());
66 }
67 size = to.ordinal() - from.ordinal() + 1;
68 }
69
70 void addAll() {
71 for (int i = 0; i < elements.length; i++)
72 elements[i] = -1;
73 elements[elements.length - 1] >>>= -universe.length;
74 size = universe.length;
75 }
76
77 void complement() {
78 for (int i = 0; i < elements.length; i++)
79 elements[i] = ~elements[i];
80 elements[elements.length - 1] &= (-1L >>> -universe.length);
81 size = universe.length - size;
82 }
83
84 /**
85 * Returns an iterator over the elements contained in this set. The
86 * iterator traverses the elements in their <i>natural order</i> (which is
87 * the order in which the enum constants are declared). The returned
88 * Iterator is a "weakly consistent" iterator that will never throw {@link
89 * ConcurrentModificationException}.
90 *
91 * @return an iterator over the elements contained in this set
92 */
93 public Iterator<E> iterator() {
94 return new EnumSetIterator<>();
95 }
96
97 private class EnumSetIterator<E extends Enum<E>> implements Iterator<E> {
98 /**
99 * A bit vector representing the elements in the current "word"
100 * of the set not yet returned by this iterator.
101 */
102 long unseen;
103
104 /**
105 * The index corresponding to unseen in the elements array.
106 */
107 int unseenIndex = 0;
108
109 /**
110 * The bit representing the last element returned by this iterator
111 * but not removed, or zero if no such element exists.
112 */
113 long lastReturned = 0;
114
115 /**
116 * The index corresponding to lastReturned in the elements array.
117 */
118 int lastReturnedIndex = 0;
119
120 EnumSetIterator() {
121 unseen = elements[0];
122 }
123
124 @Override
125 public boolean hasNext() {
126 while (unseen == 0 && unseenIndex < elements.length - 1)
127 unseen = elements[++unseenIndex];
128 return unseen != 0;
129 }
130
131 @Override
132 @SuppressWarnings("unchecked")
133 public E next() {
134 if (!hasNext())
135 throw new NoSuchElementException();
136 lastReturned = unseen & -unseen;
137 lastReturnedIndex = unseenIndex;
138 unseen -= lastReturned;
139 return (E) universe[(lastReturnedIndex << 6)
140 + Long.numberOfTrailingZeros(lastReturned)];
141 }
142
143 @Override
144 public void remove() {
145 if (lastReturned == 0)
146 throw new IllegalStateException();
147 final long oldElements = elements[lastReturnedIndex];
148 elements[lastReturnedIndex] &= ~lastReturned;
149 if (oldElements != elements[lastReturnedIndex]) {
150 size--;
151 }
152 lastReturned = 0;
153 }
154 }
155
156 /**
157 * Returns the number of elements in this set.
158 *
159 * @return the number of elements in this set
160 */
161 public int size() {
162 return size;
163 }
164
165 /**
166 * Returns {@code true} if this set contains no elements.
167 *
168 * @return {@code true} if this set contains no elements
169 */
170 public boolean isEmpty() {
171 return size == 0;
172 }
173
174 /**
175 * Returns {@code true} if this set contains the specified element.
176 *
177 * @param e element to be checked for containment in this collection
178 * @return {@code true} if this set contains the specified element
179 */
180 public boolean contains(Object e) {
181 if (e == null)
182 return false;
183 Class<?> eClass = e.getClass();
184 if (eClass != elementType && eClass.getSuperclass() != elementType)
185 return false;
186
187 int eOrdinal = ((Enum<?>)e).ordinal();
188 return (elements[eOrdinal >>> 6] & (1L << eOrdinal)) != 0;
189 }
190
191 // Modification Operations
192
193 /**
194 * Adds the specified element to this set if it is not already present.
195 *
196 * @param e element to be added to this set
197 * @return {@code true} if the set changed as a result of the call
198 *
199 * @throws NullPointerException if {@code e} is null
200 */
201 public boolean add(E e) {
202 typeCheck(e);
203
204 int eOrdinal = e.ordinal();
205 int eWordNum = eOrdinal >>> 6;
206
207 long oldElements = elements[eWordNum];
208 elements[eWordNum] |= (1L << eOrdinal);
209 boolean result = (elements[eWordNum] != oldElements);
210 if (result)
211 size++;
212 return result;
213 }
214
215 /**
216 * Removes the specified element from this set if it is present.
217 *
218 * @param e element to be removed from this set, if present
219 * @return {@code true} if the set contained the specified element
220 */
221 public boolean remove(Object e) {
222 if (e == null)
223 return false;
224 Class<?> eClass = e.getClass();
225 if (eClass != elementType && eClass.getSuperclass() != elementType)
226 return false;
227 int eOrdinal = ((Enum<?>)e).ordinal();
228 int eWordNum = eOrdinal >>> 6;
229
230 long oldElements = elements[eWordNum];
231 elements[eWordNum] &= ~(1L << eOrdinal);
232 boolean result = (elements[eWordNum] != oldElements);
233 if (result)
234 size--;
235 return result;
236 }
237
238 // Bulk Operations
239
240 /**
241 * Returns {@code true} if this set contains all of the elements
242 * in the specified collection.
243 *
244 * @param c collection to be checked for containment in this set
245 * @return {@code true} if this set contains all of the elements
246 * in the specified collection
247 * @throws NullPointerException if the specified collection is null
248 */
249 public boolean containsAll(Collection<?> c) {
250 if (!(c instanceof JumboEnumSet))
251 return super.containsAll(c);
252
253 JumboEnumSet<?> es = (JumboEnumSet<?>)c;
254 if (es.elementType != elementType)
255 return es.isEmpty();
256
257 for (int i = 0; i < elements.length; i++)
258 if ((es.elements[i] & ~elements[i]) != 0)
259 return false;
260 return true;
261 }
262
263 /**
264 * Adds all of the elements in the specified collection to this set.
265 *
266 * @param c collection whose elements are to be added to this set
267 * @return {@code true} if this set changed as a result of the call
268 * @throws NullPointerException if the specified collection or any of
269 * its elements are null
270 */
271 public boolean addAll(Collection<? extends E> c) {
272 if (!(c instanceof JumboEnumSet))
273 return super.addAll(c);
274
275 JumboEnumSet<?> es = (JumboEnumSet<?>)c;
276 if (es.elementType != elementType) {
277 if (es.isEmpty())
278 return false;
279 else
280 throw new ClassCastException(
281 es.elementType + " != " + elementType);
282 }
283
284 for (int i = 0; i < elements.length; i++)
285 elements[i] |= es.elements[i];
286 return recalculateSize();
287 }
288
289 /**
290 * Removes from this set all of its elements that are contained in
291 * the specified collection.
292 *
293 * @param c elements to be removed from this set
294 * @return {@code true} if this set changed as a result of the call
295 * @throws NullPointerException if the specified collection is null
296 */
297 public boolean removeAll(Collection<?> c) {
298 if (!(c instanceof JumboEnumSet))
299 return super.removeAll(c);
300
301 JumboEnumSet<?> es = (JumboEnumSet<?>)c;
302 if (es.elementType != elementType)
303 return false;
304
305 for (int i = 0; i < elements.length; i++)
306 elements[i] &= ~es.elements[i];
307 return recalculateSize();
308 }
309
310 /**
311 * Retains only the elements in this set that are contained in the
312 * specified collection.
313 *
314 * @param c elements to be retained in this set
315 * @return {@code true} if this set changed as a result of the call
316 * @throws NullPointerException if the specified collection is null
317 */
318 public boolean retainAll(Collection<?> c) {
319 if (!(c instanceof JumboEnumSet))
320 return super.retainAll(c);
321
322 JumboEnumSet<?> es = (JumboEnumSet<?>)c;
323 if (es.elementType != elementType) {
324 boolean changed = (size != 0);
325 clear();
326 return changed;
327 }
328
329 for (int i = 0; i < elements.length; i++)
330 elements[i] &= es.elements[i];
331 return recalculateSize();
332 }
333
334 /**
335 * Removes all of the elements from this set.
336 */
337 public void clear() {
338 Arrays.fill(elements, 0);
339 size = 0;
340 }
341
342 /**
343 * Compares the specified object with this set for equality. Returns
344 * {@code true} if the given object is also a set, the two sets have
345 * the same size, and every member of the given set is contained in
346 * this set.
347 *
348 * @param o object to be compared for equality with this set
349 * @return {@code true} if the specified object is equal to this set
350 */
351 public boolean equals(Object o) {
352 if (!(o instanceof JumboEnumSet))
353 return super.equals(o);
354
355 JumboEnumSet<?> es = (JumboEnumSet<?>)o;
356 if (es.elementType != elementType)
357 return size == 0 && es.size == 0;
358
359 return Arrays.equals(es.elements, elements);
360 }
361
362 /**
363 * Recalculates the size of the set. Returns true if it's changed.
364 */
365 private boolean recalculateSize() {
366 int oldSize = size;
367 size = 0;
368 for (long elt : elements)
369 size += Long.bitCount(elt);
370
371 return size != oldSize;
372 }
373
374 public EnumSet<E> clone() {
375 JumboEnumSet<E> result = (JumboEnumSet<E>) super.clone();
376 result.elements = result.elements.clone();
377 return result;
378 }
379 }