1 /*
2 * Copyright 2003-2006 Sun Microsystems, Inc. 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. Sun designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22 * CA 95054 USA or visit www.sun.com if you need additional information or
23 * have any 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 /**
38 * Bit vector representation of this set. The ith bit of the jth
39 * element of this array represents the presence of universe[64*j +i]
40 * in this set.
41 */
42 private long elements[];
43
44 // Redundant - maintained for performance
45 private int size = 0;
46
47 JumboEnumSet(Class<E>elementType, Enum[] universe) {
48 super(elementType, universe);
49 elements = new long[(universe.length + 63) >>> 6];
50 }
51
52 void addRange(E from, E to) {
53 int fromIndex = from.ordinal() >>> 6;
54 int toIndex = to.ordinal() >>> 6;
55
56 if (fromIndex == toIndex) {
57 elements[fromIndex] = (-1L >>> (from.ordinal() - to.ordinal() - 1))
58 << from.ordinal();
59 } else {
60 elements[fromIndex] = (-1L << from.ordinal());
61 for (int i = fromIndex + 1; i < toIndex; i++)
62 elements[i] = -1;
63 elements[toIndex] = -1L >>> (63 - to.ordinal());
64 }
65 size = to.ordinal() - from.ordinal() + 1;
66 }
67
68 void addAll() {
69 for (int i = 0; i < elements.length; i++)
70 elements[i] = -1;
71 elements[elements.length - 1] >>>= -universe.length;
72 size = universe.length;
73 }
74
75 void complement() {
76 for (int i = 0; i < elements.length; i++)
77 elements[i] = ~elements[i];
78 elements[elements.length - 1] &= (-1L >>> -universe.length);
79 size = universe.length - size;
80 }
81
82 /**
83 * Returns an iterator over the elements contained in this set. The
84 * iterator traverses the elements in their <i>natural order</i> (which is
85 * the order in which the enum constants are declared). The returned
86 * Iterator is a "weakly consistent" iterator that will never throw {@link
87 * ConcurrentModificationException}.
88 *
89 * @return an iterator over the elements contained in this set
90 */
91 public Iterator<E> iterator() {
92 return new EnumSetIterator<E>();
93 }
94
95 private class EnumSetIterator<E extends Enum<E>> implements Iterator<E> {
96 /**
97 * A bit vector representing the elements in the current "word"
98 * of the set not yet returned by this iterator.
99 */
100 long unseen;
101
102 /**
103 * The index corresponding to unseen in the elements array.
104 */
105 int unseenIndex = 0;
106
107 /**
108 * The bit representing the last element returned by this iterator
109 * but not removed, or zero if no such element exists.
110 */
111 long lastReturned = 0;
112
113 /**
114 * The index corresponding to lastReturned in the elements array.
115 */
116 int lastReturnedIndex = 0;
117
118 EnumSetIterator() {
119 unseen = elements[0];
120 }
121
122 public boolean hasNext() {
123 while (unseen == 0 && unseenIndex < elements.length - 1)
124 unseen = elements[++unseenIndex];
125 return unseen != 0;
126 }
127
128 public E next() {
129 if (!hasNext())
130 throw new NoSuchElementException();
131 lastReturned = unseen & -unseen;
132 lastReturnedIndex = unseenIndex;
133 unseen -= lastReturned;
134 return (E) universe[(lastReturnedIndex << 6)
135 + Long.numberOfTrailingZeros(lastReturned)];
136 }
137
138 public void remove() {
139 if (lastReturned == 0)
140 throw new IllegalStateException();
141 elements[lastReturnedIndex] -= lastReturned;
142 size--;
143 lastReturned = 0;
144 }
145 }
146
147 /**
148 * Returns the number of elements in this set.
149 *
150 * @return the number of elements in this set
151 */
152 public int size() {
153 return size;
154 }
155
156 /**
157 * Returns <tt>true</tt> if this set contains no elements.
158 *
159 * @return <tt>true</tt> if this set contains no elements
160 */
161 public boolean isEmpty() {
162 return size == 0;
163 }
164
165 /**
166 * Returns <tt>true</tt> if this set contains the specified element.
167 *
168 * @param e element to be checked for containment in this collection
169 * @return <tt>true</tt> if this set contains the specified element
170 */
171 public boolean contains(Object e) {
172 if (e == null)
173 return false;
174 Class eClass = e.getClass();
175 if (eClass != elementType && eClass.getSuperclass() != elementType)
176 return false;
177
178 int eOrdinal = ((Enum)e).ordinal();
179 return (elements[eOrdinal >>> 6] & (1L << eOrdinal)) != 0;
180 }
181
182 // Modification Operations
183
184 /**
185 * Adds the specified element to this set if it is not already present.
186 *
187 * @param e element to be added to this set
188 * @return <tt>true</tt> if the set changed as a result of the call
189 *
190 * @throws NullPointerException if <tt>e</tt> is null
191 */
192 public boolean add(E e) {
193 typeCheck(e);
194
195 int eOrdinal = e.ordinal();
196 int eWordNum = eOrdinal >>> 6;
197
198 long oldElements = elements[eWordNum];
199 elements[eWordNum] |= (1L << eOrdinal);
200 boolean result = (elements[eWordNum] != oldElements);
201 if (result)
202 size++;
203 return result;
204 }
205
206 /**
207 * Removes the specified element from this set if it is present.
208 *
209 * @param e element to be removed from this set, if present
210 * @return <tt>true</tt> if the set contained the specified element
211 */
212 public boolean remove(Object e) {
213 if (e == null)
214 return false;
215 Class eClass = e.getClass();
216 if (eClass != elementType && eClass.getSuperclass() != elementType)
217 return false;
218 int eOrdinal = ((Enum)e).ordinal();
219 int eWordNum = eOrdinal >>> 6;
220
221 long oldElements = elements[eWordNum];
222 elements[eWordNum] &= ~(1L << eOrdinal);
223 boolean result = (elements[eWordNum] != oldElements);
224 if (result)
225 size--;
226 return result;
227 }
228
229 // Bulk Operations
230
231 /**
232 * Returns <tt>true</tt> if this set contains all of the elements
233 * in the specified collection.
234 *
235 * @param c collection to be checked for containment in this set
236 * @return <tt>true</tt> if this set contains all of the elements
237 * in the specified collection
238 * @throws NullPointerException if the specified collection is null
239 */
240 public boolean containsAll(Collection<?> c) {
241 if (!(c instanceof JumboEnumSet))
242 return super.containsAll(c);
243
244 JumboEnumSet es = (JumboEnumSet)c;
245 if (es.elementType != elementType)
246 return es.isEmpty();
247
248 for (int i = 0; i < elements.length; i++)
249 if ((es.elements[i] & ~elements[i]) != 0)
250 return false;
251 return true;
252 }
253
254 /**
255 * Adds all of the elements in the specified collection to this set.
256 *
257 * @param c collection whose elements are to be added to this set
258 * @return <tt>true</tt> if this set changed as a result of the call
259 * @throws NullPointerException if the specified collection or any of
260 * its elements are null
261 */
262 public boolean addAll(Collection<? extends E> c) {
263 if (!(c instanceof JumboEnumSet))
264 return super.addAll(c);
265
266 JumboEnumSet es = (JumboEnumSet)c;
267 if (es.elementType != elementType) {
268 if (es.isEmpty())
269 return false;
270 else
271 throw new ClassCastException(
272 es.elementType + " != " + elementType);
273 }
274
275 for (int i = 0; i < elements.length; i++)
276 elements[i] |= es.elements[i];
277 return recalculateSize();
278 }
279
280 /**
281 * Removes from this set all of its elements that are contained in
282 * the specified collection.
283 *
284 * @param c elements to be removed from this set
285 * @return <tt>true</tt> if this set changed as a result of the call
286 * @throws NullPointerException if the specified collection is null
287 */
288 public boolean removeAll(Collection<?> c) {
289 if (!(c instanceof JumboEnumSet))
290 return super.removeAll(c);
291
292 JumboEnumSet es = (JumboEnumSet)c;
293 if (es.elementType != elementType)
294 return false;
295
296 for (int i = 0; i < elements.length; i++)
297 elements[i] &= ~es.elements[i];
298 return recalculateSize();
299 }
300
301 /**
302 * Retains only the elements in this set that are contained in the
303 * specified collection.
304 *
305 * @param c elements to be retained in this set
306 * @return <tt>true</tt> if this set changed as a result of the call
307 * @throws NullPointerException if the specified collection is null
308 */
309 public boolean retainAll(Collection<?> c) {
310 if (!(c instanceof JumboEnumSet))
311 return super.retainAll(c);
312
313 JumboEnumSet<?> es = (JumboEnumSet<?>)c;
314 if (es.elementType != elementType) {
315 boolean changed = (size != 0);
316 clear();
317 return changed;
318 }
319
320 for (int i = 0; i < elements.length; i++)
321 elements[i] &= es.elements[i];
322 return recalculateSize();
323 }
324
325 /**
326 * Removes all of the elements from this set.
327 */
328 public void clear() {
329 Arrays.fill(elements, 0);
330 size = 0;
331 }
332
333 /**
334 * Compares the specified object with this set for equality. Returns
335 * <tt>true</tt> if the given object is also a set, the two sets have
336 * the same size, and every member of the given set is contained in
337 * this set.
338 *
339 * @param e object to be compared for equality with this set
340 * @return <tt>true</tt> if the specified object is equal to this set
341 */
342 public boolean equals(Object o) {
343 if (!(o instanceof JumboEnumSet))
344 return super.equals(o);
345
346 JumboEnumSet es = (JumboEnumSet)o;
347 if (es.elementType != elementType)
348 return size == 0 && es.size == 0;
349
350 return Arrays.equals(es.elements, elements);
351 }
352
353 /**
354 * Recalculates the size of the set. Returns true if it's changed.
355 */
356 private boolean recalculateSize() {
357 int oldSize = size;
358 size = 0;
359 for (long elt : elements)
360 size += Long.bitCount(elt);
361
362 return size != oldSize;
363 }
364
365 public EnumSet<E> clone() {
366 JumboEnumSet<E> result = (JumboEnumSet<E>) super.clone();
367 result.elements = result.elements.clone();
368 return result;
369 }
370 }
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