001 /*
002 * Copyright 2003-2006 Sun Microsystems, Inc. All Rights Reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation. Sun designates this
008 * particular file as subject to the "Classpath" exception as provided
009 * by Sun in the LICENSE file that accompanied this code.
010 *
011 * This code is distributed in the hope that it will be useful, but WITHOUT
012 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
013 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
014 * version 2 for more details (a copy is included in the LICENSE file that
015 * accompanied this code).
016 *
017 * You should have received a copy of the GNU General Public License version
018 * 2 along with this work; if not, write to the Free Software Foundation,
019 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
020 *
021 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
022 * CA 95054 USA or visit www.sun.com if you need additional information or
023 * have any questions.
024 */
025
026 package java.util;
027
028 /**
029 * Private implementation class for EnumSet, for "jumbo" enum types
030 * (i.e., those with more than 64 elements).
031 *
032 * @author Josh Bloch
033 * @since 1.5
034 * @serial exclude
035 */
036 class JumboEnumSet<E extends Enum<E>> extends EnumSet<E> {
037 /**
038 * Bit vector representation of this set. The ith bit of the jth
039 * element of this array represents the presence of universe[64*j +i]
040 * in this set.
041 */
042 private long elements[];
043
044 // Redundant - maintained for performance
045 private int size = 0;
046
047 JumboEnumSet(Class<E> elementType, Enum[] universe) {
048 super (elementType, universe);
049 elements = new long[(universe.length + 63) >>> 6];
050 }
051
052 void addRange(E from, E to) {
053 int fromIndex = from.ordinal() >>> 6;
054 int toIndex = to.ordinal() >>> 6;
055
056 if (fromIndex == toIndex) {
057 elements[fromIndex] = (-1L >>> (from.ordinal()
058 - to.ordinal() - 1)) << from.ordinal();
059 } else {
060 elements[fromIndex] = (-1L << from.ordinal());
061 for (int i = fromIndex + 1; i < toIndex; i++)
062 elements[i] = -1;
063 elements[toIndex] = -1L >>> (63 - to.ordinal());
064 }
065 size = to.ordinal() - from.ordinal() + 1;
066 }
067
068 void addAll() {
069 for (int i = 0; i < elements.length; i++)
070 elements[i] = -1;
071 elements[elements.length - 1] >>>= -universe.length;
072 size = universe.length;
073 }
074
075 void complement() {
076 for (int i = 0; i < elements.length; i++)
077 elements[i] = ~elements[i];
078 elements[elements.length - 1] &= (-1L >>> -universe.length);
079 size = universe.length - size;
080 }
081
082 /**
083 * Returns an iterator over the elements contained in this set. The
084 * iterator traverses the elements in their <i>natural order</i> (which is
085 * the order in which the enum constants are declared). The returned
086 * Iterator is a "weakly consistent" iterator that will never throw {@link
087 * ConcurrentModificationException}.
088 *
089 * @return an iterator over the elements contained in this set
090 */
091 public Iterator<E> iterator() {
092 return new EnumSetIterator<E>();
093 }
094
095 private class EnumSetIterator<E extends Enum<E>> implements
096 Iterator<E> {
097 /**
098 * A bit vector representing the elements in the current "word"
099 * of the set not yet returned by this iterator.
100 */
101 long unseen;
102
103 /**
104 * The index corresponding to unseen in the elements array.
105 */
106 int unseenIndex = 0;
107
108 /**
109 * The bit representing the last element returned by this iterator
110 * but not removed, or zero if no such element exists.
111 */
112 long lastReturned = 0;
113
114 /**
115 * The index corresponding to lastReturned in the elements array.
116 */
117 int lastReturnedIndex = 0;
118
119 EnumSetIterator() {
120 unseen = elements[0];
121 }
122
123 public boolean hasNext() {
124 while (unseen == 0 && unseenIndex < elements.length - 1)
125 unseen = elements[++unseenIndex];
126 return unseen != 0;
127 }
128
129 public E next() {
130 if (!hasNext())
131 throw new NoSuchElementException();
132 lastReturned = unseen & -unseen;
133 lastReturnedIndex = unseenIndex;
134 unseen -= lastReturned;
135 return (E) universe[(lastReturnedIndex << 6)
136 + Long.numberOfTrailingZeros(lastReturned)];
137 }
138
139 public void remove() {
140 if (lastReturned == 0)
141 throw new IllegalStateException();
142 elements[lastReturnedIndex] -= lastReturned;
143 size--;
144 lastReturned = 0;
145 }
146 }
147
148 /**
149 * Returns the number of elements in this set.
150 *
151 * @return the number of elements in this set
152 */
153 public int size() {
154 return size;
155 }
156
157 /**
158 * Returns <tt>true</tt> if this set contains no elements.
159 *
160 * @return <tt>true</tt> if this set contains no elements
161 */
162 public boolean isEmpty() {
163 return size == 0;
164 }
165
166 /**
167 * Returns <tt>true</tt> if this set contains the specified element.
168 *
169 * @param e element to be checked for containment in this collection
170 * @return <tt>true</tt> if this set contains the specified element
171 */
172 public boolean contains(Object e) {
173 if (e == null)
174 return false;
175 Class eClass = e.getClass();
176 if (eClass != elementType
177 && eClass.getSuperclass() != elementType)
178 return false;
179
180 int eOrdinal = ((Enum) e).ordinal();
181 return (elements[eOrdinal >>> 6] & (1L << eOrdinal)) != 0;
182 }
183
184 // Modification Operations
185
186 /**
187 * Adds the specified element to this set if it is not already present.
188 *
189 * @param e element to be added to this set
190 * @return <tt>true</tt> if the set changed as a result of the call
191 *
192 * @throws NullPointerException if <tt>e</tt> is null
193 */
194 public boolean add(E e) {
195 typeCheck(e);
196
197 int eOrdinal = e.ordinal();
198 int eWordNum = eOrdinal >>> 6;
199
200 long oldElements = elements[eWordNum];
201 elements[eWordNum] |= (1L << eOrdinal);
202 boolean result = (elements[eWordNum] != oldElements);
203 if (result)
204 size++;
205 return result;
206 }
207
208 /**
209 * Removes the specified element from this set if it is present.
210 *
211 * @param e element to be removed from this set, if present
212 * @return <tt>true</tt> if the set contained the specified element
213 */
214 public boolean remove(Object e) {
215 if (e == null)
216 return false;
217 Class eClass = e.getClass();
218 if (eClass != elementType
219 && eClass.getSuperclass() != elementType)
220 return false;
221 int eOrdinal = ((Enum) e).ordinal();
222 int eWordNum = eOrdinal >>> 6;
223
224 long oldElements = elements[eWordNum];
225 elements[eWordNum] &= ~(1L << eOrdinal);
226 boolean result = (elements[eWordNum] != oldElements);
227 if (result)
228 size--;
229 return result;
230 }
231
232 // Bulk Operations
233
234 /**
235 * Returns <tt>true</tt> if this set contains all of the elements
236 * in the specified collection.
237 *
238 * @param c collection to be checked for containment in this set
239 * @return <tt>true</tt> if this set contains all of the elements
240 * in the specified collection
241 * @throws NullPointerException if the specified collection is null
242 */
243 public boolean containsAll(Collection<?> c) {
244 if (!(c instanceof JumboEnumSet))
245 return super .containsAll(c);
246
247 JumboEnumSet es = (JumboEnumSet) c;
248 if (es.elementType != elementType)
249 return es.isEmpty();
250
251 for (int i = 0; i < elements.length; i++)
252 if ((es.elements[i] & ~elements[i]) != 0)
253 return false;
254 return true;
255 }
256
257 /**
258 * Adds all of the elements in the specified collection to this set.
259 *
260 * @param c collection whose elements are to be added to this set
261 * @return <tt>true</tt> if this set changed as a result of the call
262 * @throws NullPointerException if the specified collection or any of
263 * its elements are null
264 */
265 public boolean addAll(Collection<? extends E> c) {
266 if (!(c instanceof JumboEnumSet))
267 return super .addAll(c);
268
269 JumboEnumSet es = (JumboEnumSet) c;
270 if (es.elementType != elementType) {
271 if (es.isEmpty())
272 return false;
273 else
274 throw new ClassCastException(es.elementType + " != "
275 + elementType);
276 }
277
278 for (int i = 0; i < elements.length; i++)
279 elements[i] |= es.elements[i];
280 return recalculateSize();
281 }
282
283 /**
284 * Removes from this set all of its elements that are contained in
285 * the specified collection.
286 *
287 * @param c elements to be removed from this set
288 * @return <tt>true</tt> if this set changed as a result of the call
289 * @throws NullPointerException if the specified collection is null
290 */
291 public boolean removeAll(Collection<?> c) {
292 if (!(c instanceof JumboEnumSet))
293 return super .removeAll(c);
294
295 JumboEnumSet es = (JumboEnumSet) c;
296 if (es.elementType != elementType)
297 return false;
298
299 for (int i = 0; i < elements.length; i++)
300 elements[i] &= ~es.elements[i];
301 return recalculateSize();
302 }
303
304 /**
305 * Retains only the elements in this set that are contained in the
306 * specified collection.
307 *
308 * @param c elements to be retained in this set
309 * @return <tt>true</tt> if this set changed as a result of the call
310 * @throws NullPointerException if the specified collection is null
311 */
312 public boolean retainAll(Collection<?> c) {
313 if (!(c instanceof JumboEnumSet))
314 return super .retainAll(c);
315
316 JumboEnumSet<?> es = (JumboEnumSet<?>) c;
317 if (es.elementType != elementType) {
318 boolean changed = (size != 0);
319 clear();
320 return changed;
321 }
322
323 for (int i = 0; i < elements.length; i++)
324 elements[i] &= es.elements[i];
325 return recalculateSize();
326 }
327
328 /**
329 * Removes all of the elements from this set.
330 */
331 public void clear() {
332 Arrays.fill(elements, 0);
333 size = 0;
334 }
335
336 /**
337 * Compares the specified object with this set for equality. Returns
338 * <tt>true</tt> if the given object is also a set, the two sets have
339 * the same size, and every member of the given set is contained in
340 * this set.
341 *
342 * @param e object to be compared for equality with this set
343 * @return <tt>true</tt> if the specified object is equal to this set
344 */
345 public boolean equals(Object o) {
346 if (!(o instanceof JumboEnumSet))
347 return super .equals(o);
348
349 JumboEnumSet es = (JumboEnumSet) o;
350 if (es.elementType != elementType)
351 return size == 0 && es.size == 0;
352
353 return Arrays.equals(es.elements, elements);
354 }
355
356 /**
357 * Recalculates the size of the set. Returns true if it's changed.
358 */
359 private boolean recalculateSize() {
360 int oldSize = size;
361 size = 0;
362 for (long elt : elements)
363 size += Long.bitCount(elt);
364
365 return size != oldSize;
366 }
367
368 public EnumSet<E> clone() {
369 JumboEnumSet<E> result = (JumboEnumSet<E>) super .clone();
370 result.elements = (long[]) result.elements.clone();
371 return result;
372 }
373 }
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