J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 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 = (long[]) result.elements.clone(); |
| 368 | return result; |
| 369 | } |
| 370 | } |