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| 1 | /* | ||
| 2 | * Copyright (c) 2003, 2011, 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 | import sun.misc.SharedSecrets; | ||
| 29 | |||
| 30 | /** | ||
| 31 | * A specialized {@link Set} implementation for use with enum types. All of | ||
| 32 | * the elements in an enum set must come from a single enum type that is | ||
| 33 | * specified, explicitly or implicitly, when the set is created. Enum sets | ||
| 34 | * are represented internally as bit vectors. This representation is | ||
| 35 | * extremely compact and efficient. The space and time performance of this | ||
| 36 | * class should be good enough to allow its use as a high-quality, typesafe | ||
| 37 | * alternative to traditional <tt>int</tt>-based "bit flags." Even bulk | ||
| 38 | * operations (such as <tt>containsAll</tt> and <tt>retainAll</tt>) should | ||
| 39 | * run very quickly if their argument is also an enum set. | ||
| 40 | * | ||
| 41 | * <p>The iterator returned by the <tt>iterator</tt> method traverses the | ||
| 42 | * elements in their <i>natural order</i> (the order in which the enum | ||
| 43 | * constants are declared). The returned iterator is <i>weakly | ||
| 44 | * consistent</i>: it will never throw {@link ConcurrentModificationException} | ||
| 45 | * and it may or may not show the effects of any modifications to the set that | ||
| 46 | * occur while the iteration is in progress. | ||
| 47 | * | ||
| 48 | * <p>Null elements are not permitted. Attempts to insert a null element | ||
| 49 | * will throw {@link NullPointerException}. Attempts to test for the | ||
| 50 | * presence of a null element or to remove one will, however, function | ||
| 51 | * properly. | ||
| 52 | * | ||
| 53 | * <P>Like most collection implementations, <tt>EnumSet</tt> is not | ||
| 54 | * synchronized. If multiple threads access an enum set concurrently, and at | ||
| 55 | * least one of the threads modifies the set, it should be synchronized | ||
| 56 | * externally. This is typically accomplished by synchronizing on some | ||
| 57 | * object that naturally encapsulates the enum set. If no such object exists, | ||
| 58 | * the set should be "wrapped" using the {@link Collections#synchronizedSet} | ||
| 59 | * method. This is best done at creation time, to prevent accidental | ||
| 60 | * unsynchronized access: | ||
| 61 | * | ||
| 62 | * <pre> | ||
| 63 | * Set<MyEnum> s = Collections.synchronizedSet(EnumSet.noneOf(MyEnum.class)); | ||
| 64 | * </pre> | ||
| 65 | * | ||
| 66 | * <p>Implementation note: All basic operations execute in constant time. | ||
| 67 | * They are likely (though not guaranteed) to be much faster than their | ||
| 68 | * {@link HashSet} counterparts. Even bulk operations execute in | ||
| 69 | * constant time if their argument is also an enum set. | ||
| 70 | * | ||
| 71 | * <p>This class is a member of the | ||
| 72 | * <a href="{@docRoot}/../technotes/guides/collections/index.html"> | ||
| 73 | * Java Collections Framework</a>. | ||
| 74 | * | ||
| 75 | * @author Josh Bloch | ||
| 76 | * @since 1.5 | ||
| 77 | * @see EnumMap | ||
| 78 | * @serial exclude | ||
| 79 | */ | ||
| 80 | public abstract class EnumSet<E extends Enum<E>> extends AbstractSet<E> | ||
| 81 | implements Cloneable, java.io.Serializable | ||
| 82 | { | ||
| 83 | /** | ||
| 84 | * The class of all the elements of this set. | ||
| 85 | */ | ||
| 86 | final Class<E> elementType; | ||
| 87 | |||
| 88 | /** | ||
| 89 | * All of the values comprising T. (Cached for performance.) | ||
| 90 | */ | ||
| 91 | final Enum[] universe; | ||
| 92 | |||
| 93 | private static Enum[] ZERO_LENGTH_ENUM_ARRAY = new Enum[0]; | ||
| 94 | |||
| 95 | EnumSet(Class<E>elementType, Enum[] universe) { | ||
| 96 | this.elementType = elementType; | ||
| 97 | this.universe = universe; | ||
| 98 | } | ||
| 99 | |||
| 100 | /** | ||
| 101 | * Creates an empty enum set with the specified element type. | ||
| 102 | * | ||
| 103 | * @param elementType the class object of the element type for this enum | ||
| 104 | * set | ||
| 105 | * @throws NullPointerException if <tt>elementType</tt> is null | ||
| 106 | */ | ||
| 107 | public static <E extends Enum<E>> EnumSet<E> noneOf(Class<E> elementType) { | ||
| 108 | Enum[] universe = getUniverse(elementType); | ||
| 109 | if (universe == null) | ||
| 110 | throw new ClassCastException(elementType + " not an enum"); | ||
| 111 | |||
| 112 | if (universe.length <= 64) | ||
| 113 | return new RegularEnumSet<>(elementType, universe); | ||
| 114 | else | ||
| 115 | return new JumboEnumSet<>(elementType, universe); | ||
| 116 | } | ||
| 117 | |||
| 118 | /** | ||
| 119 | * Creates an enum set containing all of the elements in the specified | ||
| 120 | * element type. | ||
| 121 | * | ||
| 122 | * @param elementType the class object of the element type for this enum | ||
| 123 | * set | ||
| 124 | * @throws NullPointerException if <tt>elementType</tt> is null | ||
| 125 | */ | ||
| 126 | public static <E extends Enum<E>> EnumSet<E> allOf(Class<E> elementType) { | ||
| 127 | EnumSet<E> result = noneOf(elementType); | ||
| 128 | result.addAll(); | ||
| 129 | return result; | ||
| 130 | } | ||
| 131 | |||
| 132 | /** | ||
| 133 | * Adds all of the elements from the appropriate enum type to this enum | ||
| 134 | * set, which is empty prior to the call. | ||
| 135 | */ | ||
| 136 | abstract void addAll(); | ||
| 137 | |||
| 138 | /** | ||
| 139 | * Creates an enum set with the same element type as the specified enum | ||
| 140 | * set, initially containing the same elements (if any). | ||
| 141 | * | ||
| 142 | * @param s the enum set from which to initialize this enum set | ||
| 143 | * @throws NullPointerException if <tt>s</tt> is null | ||
| 144 | */ | ||
| 145 | public static <E extends Enum<E>> EnumSet<E> copyOf(EnumSet<E> s) { | ||
| 146 | return s.clone(); | ||
| 147 | } | ||
| 148 | |||
| 149 | /** | ||
| 150 | * Creates an enum set initialized from the specified collection. If | ||
| 151 | * the specified collection is an <tt>EnumSet</tt> instance, this static | ||
| 152 | * factory method behaves identically to {@link #copyOf(EnumSet)}. | ||
| 153 | * Otherwise, the specified collection must contain at least one element | ||
| 154 | * (in order to determine the new enum set's element type). | ||
| 155 | * | ||
| 156 | * @param c the collection from which to initialize this enum set | ||
| 157 | * @throws IllegalArgumentException if <tt>c</tt> is not an | ||
| 158 | * <tt>EnumSet</tt> instance and contains no elements | ||
| 159 | * @throws NullPointerException if <tt>c</tt> is null | ||
| 160 | */ | ||
| 161 | public static <E extends Enum<E>> EnumSet<E> copyOf(Collection<E> c) { | ||
| 162 | if (c instanceof EnumSet) { | ||
| 163 | return ((EnumSet<E>)c).clone(); | ||
| 164 | } else { | ||
| 165 | if (c.isEmpty()) | ||
| 166 | throw new IllegalArgumentException("Collection is empty"); | ||
| 167 | Iterator<E> i = c.iterator(); | ||
| 168 | E first = i.next(); | ||
| 169 | EnumSet<E> result = EnumSet.of(first); | ||
| 170 | while (i.hasNext()) | ||
| 171 | result.add(i.next()); | ||
| 172 | return result; | ||
| 173 | } | ||
| 174 | } | ||
| 175 | |||
| 176 | /** | ||
| 177 | * Creates an enum set with the same element type as the specified enum | ||
| 178 | * set, initially containing all the elements of this type that are | ||
| 179 | * <i>not</i> contained in the specified set. | ||
| 180 | * | ||
| 181 | * @param s the enum set from whose complement to initialize this enum set | ||
| 182 | * @throws NullPointerException if <tt>s</tt> is null | ||
| 183 | */ | ||
| 184 | public static <E extends Enum<E>> EnumSet<E> complementOf(EnumSet<E> s) { | ||
| 185 | EnumSet<E> result = copyOf(s); | ||
| 186 | result.complement(); | ||
| 187 | return result; | ||
| 188 | } | ||
| 189 | |||
| 190 | /** | ||
| 191 | * Creates an enum set initially containing the specified element. | ||
| 192 | * | ||
| 193 | * Overloadings of this method exist to initialize an enum set with | ||
| 194 | * one through five elements. A sixth overloading is provided that | ||
| 195 | * uses the varargs feature. This overloading may be used to create | ||
| 196 | * an enum set initially containing an arbitrary number of elements, but | ||
| 197 | * is likely to run slower than the overloadings that do not use varargs. | ||
| 198 | * | ||
| 199 | * @param e the element that this set is to contain initially | ||
| 200 | * @throws NullPointerException if <tt>e</tt> is null | ||
| 201 | * @return an enum set initially containing the specified element | ||
| 202 | */ | ||
| 203 | public static <E extends Enum<E>> EnumSet<E> of(E e) { | ||
| 204 | EnumSet<E> result = noneOf(e.getDeclaringClass()); | ||
| 205 | result.add(e); | ||
| 206 | return result; | ||
| 207 | } | ||
| 208 | |||
| 209 | /** | ||
| 210 | * Creates an enum set initially containing the specified elements. | ||
| 211 | * | ||
| 212 | * Overloadings of this method exist to initialize an enum set with | ||
| 213 | * one through five elements. A sixth overloading is provided that | ||
| 214 | * uses the varargs feature. This overloading may be used to create | ||
| 215 | * an enum set initially containing an arbitrary number of elements, but | ||
| 216 | * is likely to run slower than the overloadings that do not use varargs. | ||
| 217 | * | ||
| 218 | * @param e1 an element that this set is to contain initially | ||
| 219 | * @param e2 another element that this set is to contain initially | ||
| 220 | * @throws NullPointerException if any parameters are null | ||
| 221 | * @return an enum set initially containing the specified elements | ||
| 222 | */ | ||
| 223 | public static <E extends Enum<E>> EnumSet<E> of(E e1, E e2) { | ||
| 224 | EnumSet<E> result = noneOf(e1.getDeclaringClass()); | ||
| 225 | result.add(e1); | ||
| 226 | result.add(e2); | ||
| 227 | return result; | ||
| 228 | } | ||
| 229 | |||
| 230 | /** | ||
| 231 | * Creates an enum set initially containing the specified elements. | ||
| 232 | * | ||
| 233 | * Overloadings of this method exist to initialize an enum set with | ||
| 234 | * one through five elements. A sixth overloading is provided that | ||
| 235 | * uses the varargs feature. This overloading may be used to create | ||
| 236 | * an enum set initially containing an arbitrary number of elements, but | ||
| 237 | * is likely to run slower than the overloadings that do not use varargs. | ||
| 238 | * | ||
| 239 | * @param e1 an element that this set is to contain initially | ||
| 240 | * @param e2 another element that this set is to contain initially | ||
| 241 | * @param e3 another element that this set is to contain initially | ||
| 242 | * @throws NullPointerException if any parameters are null | ||
| 243 | * @return an enum set initially containing the specified elements | ||
| 244 | */ | ||
| 245 | public static <E extends Enum<E>> EnumSet<E> of(E e1, E e2, E e3) { | ||
| 246 | EnumSet<E> result = noneOf(e1.getDeclaringClass()); | ||
| 247 | result.add(e1); | ||
| 248 | result.add(e2); | ||
| 249 | result.add(e3); | ||
| 250 | return result; | ||
| 251 | } | ||
| 252 | |||
| 253 | /** | ||
| 254 | * Creates an enum set initially containing the specified elements. | ||
| 255 | * | ||
| 256 | * Overloadings of this method exist to initialize an enum set with | ||
| 257 | * one through five elements. A sixth overloading is provided that | ||
| 258 | * uses the varargs feature. This overloading may be used to create | ||
| 259 | * an enum set initially containing an arbitrary number of elements, but | ||
| 260 | * is likely to run slower than the overloadings that do not use varargs. | ||
| 261 | * | ||
| 262 | * @param e1 an element that this set is to contain initially | ||
| 263 | * @param e2 another element that this set is to contain initially | ||
| 264 | * @param e3 another element that this set is to contain initially | ||
| 265 | * @param e4 another element that this set is to contain initially | ||
| 266 | * @throws NullPointerException if any parameters are null | ||
| 267 | * @return an enum set initially containing the specified elements | ||
| 268 | */ | ||
| 269 | public static <E extends Enum<E>> EnumSet<E> of(E e1, E e2, E e3, E e4) { | ||
| 270 | EnumSet<E> result = noneOf(e1.getDeclaringClass()); | ||
| 271 | result.add(e1); | ||
| 272 | result.add(e2); | ||
| 273 | result.add(e3); | ||
| 274 | result.add(e4); | ||
| 275 | return result; | ||
| 276 | } | ||
| 277 | |||
| 278 | /** | ||
| 279 | * Creates an enum set initially containing the specified elements. | ||
| 280 | * | ||
| 281 | * Overloadings of this method exist to initialize an enum set with | ||
| 282 | * one through five elements. A sixth overloading is provided that | ||
| 283 | * uses the varargs feature. This overloading may be used to create | ||
| 284 | * an enum set initially containing an arbitrary number of elements, but | ||
| 285 | * is likely to run slower than the overloadings that do not use varargs. | ||
| 286 | * | ||
| 287 | * @param e1 an element that this set is to contain initially | ||
| 288 | * @param e2 another element that this set is to contain initially | ||
| 289 | * @param e3 another element that this set is to contain initially | ||
| 290 | * @param e4 another element that this set is to contain initially | ||
| 291 | * @param e5 another element that this set is to contain initially | ||
| 292 | * @throws NullPointerException if any parameters are null | ||
| 293 | * @return an enum set initially containing the specified elements | ||
| 294 | */ | ||
| 295 | public static <E extends Enum<E>> EnumSet<E> of(E e1, E e2, E e3, E e4, | ||
| 296 | E e5) | ||
| 297 | { | ||
| 298 | EnumSet<E> result = noneOf(e1.getDeclaringClass()); | ||
| 299 | result.add(e1); | ||
| 300 | result.add(e2); | ||
| 301 | result.add(e3); | ||
| 302 | result.add(e4); | ||
| 303 | result.add(e5); | ||
| 304 | return result; | ||
| 305 | } | ||
| 306 | |||
| 307 | /** | ||
| 308 | * Creates an enum set initially containing the specified elements. | ||
| 309 | * This factory, whose parameter list uses the varargs feature, may | ||
| 310 | * be used to create an enum set initially containing an arbitrary | ||
| 311 | * number of elements, but it is likely to run slower than the overloadings | ||
| 312 | * that do not use varargs. | ||
| 313 | * | ||
| 314 | * @param first an element that the set is to contain initially | ||
| 315 | * @param rest the remaining elements the set is to contain initially | ||
| 316 | * @throws NullPointerException if any of the specified elements are null, | ||
| 317 | * or if <tt>rest</tt> is null | ||
| 318 | * @return an enum set initially containing the specified elements | ||
| 319 | */ | ||
| 320 | @SafeVarargs | ||
| 321 | public static <E extends Enum<E>> EnumSet<E> of(E first, E... rest) { | ||
| 322 | EnumSet<E> result = noneOf(first.getDeclaringClass()); | ||
| 323 | result.add(first); | ||
| 324 | for (E e : rest) | ||
| 325 | result.add(e); | ||
| 326 | return result; | ||
| 327 | } | ||
| 328 | |||
| 329 | /** | ||
| 330 | * Creates an enum set initially containing all of the elements in the | ||
| 331 | * range defined by the two specified endpoints. The returned set will | ||
| 332 | * contain the endpoints themselves, which may be identical but must not | ||
| 333 | * be out of order. | ||
| 334 | * | ||
| 335 | * @param from the first element in the range | ||
| 336 | * @param to the last element in the range | ||
| 337 | * @throws NullPointerException if {@code from} or {@code to} are null | ||
| 338 | * @throws IllegalArgumentException if {@code from.compareTo(to) > 0} | ||
| 339 | * @return an enum set initially containing all of the elements in the | ||
| 340 | * range defined by the two specified endpoints | ||
| 341 | */ | ||
| 342 | public static <E extends Enum<E>> EnumSet<E> range(E from, E to) { | ||
| 343 | if (from.compareTo(to) > 0) | ||
| 344 | throw new IllegalArgumentException(from + " > " + to); | ||
| 345 | EnumSet<E> result = noneOf(from.getDeclaringClass()); | ||
| 346 | result.addRange(from, to); | ||
| 347 | return result; | ||
| 348 | } | ||
| 349 | |||
| 350 | /** | ||
| 351 | * Adds the specified range to this enum set, which is empty prior | ||
| 352 | * to the call. | ||
| 353 | */ | ||
| 354 | abstract void addRange(E from, E to); | ||
| 355 | |||
| 356 | /** | ||
| 357 | * Returns a copy of this set. | ||
| 358 | * | ||
| 359 | * @return a copy of this set | ||
| 360 | */ | ||
| 361 | public EnumSet<E> clone() { | ||
| 362 | try { | ||
| 363 | return (EnumSet<E>) super.clone(); | ||
| 364 | } catch(CloneNotSupportedException e) { | ||
| 365 | throw new AssertionError(e); | ||
| 366 | } | ||
| 367 | } | ||
| 368 | |||
| 369 | /** | ||
| 370 | * Complements the contents of this enum set. | ||
| 371 | */ | ||
| 372 | abstract void complement(); | ||
| 373 | |||
| 374 | /** | ||
| 375 | * Throws an exception if e is not of the correct type for this enum set. | ||
| 376 | */ | ||
| 377 | final void typeCheck(E e) { | ||
| 378 | Class eClass = e.getClass(); | ||
| 379 | if (eClass != elementType && eClass.getSuperclass() != elementType) | ||
| 380 | throw new ClassCastException(eClass + " != " + elementType); | ||
| 381 | } | ||
| 382 | |||
| 383 | /** | ||
| 384 | * Returns all of the values comprising E. | ||
| 385 | * The result is uncloned, cached, and shared by all callers. | ||
| 386 | */ | ||
| 387 | private static <E extends Enum<E>> E[] getUniverse(Class<E> elementType) { | ||
| 388 | return SharedSecrets.getJavaLangAccess() | ||
| 389 | .getEnumConstantsShared(elementType); | ||
| 390 | } | ||
| 391 | |||
| 392 | /** | ||
| 393 | * This class is used to serialize all EnumSet instances, regardless of | ||
| 394 | * implementation type. It captures their "logical contents" and they | ||
| 395 | * are reconstructed using public static factories. This is necessary | ||
| 396 | * to ensure that the existence of a particular implementation type is | ||
| 397 | * an implementation detail. | ||
| 398 | * | ||
| 399 | * @serial include | ||
| 400 | */ | ||
| 401 | private static class SerializationProxy <E extends Enum<E>> | ||
| 402 | implements java.io.Serializable | ||
| 403 | { | ||
| 404 | /** | ||
| 405 | * The element type of this enum set. | ||
| 406 | * | ||
| 407 | * @serial | ||
| 408 | */ | ||
| 409 | private final Class<E> elementType; | ||
| 410 | |||
| 411 | /** | ||
| 412 | * The elements contained in this enum set. | ||
| 413 | * | ||
| 414 | * @serial | ||
| 415 | */ | ||
| 416 | private final Enum[] elements; | ||
| 417 | |||
| 418 | SerializationProxy(EnumSet<E> set) { | ||
| 419 | elementType = set.elementType; | ||
| 420 | elements = set.toArray(ZERO_LENGTH_ENUM_ARRAY); | ||
| 421 | } | ||
| 422 | |||
| 423 | private Object readResolve() { | ||
| 424 | EnumSet<E> result = EnumSet.noneOf(elementType); | ||
| 425 | for (Enum e : elements) | ||
| 426 | result.add((E)e); | ||
| 427 | return result; | ||
| 428 | } | ||
| 429 | |||
| 430 | private static final long serialVersionUID = 362491234563181265L; | ||
| 431 | } | ||
| 432 | |||
| 433 | Object writeReplace() { | ||
| 434 | return new SerializationProxy<>(this); | ||
| 435 | } | ||
| 436 | |||
| 437 | // readObject method for the serialization proxy pattern | ||
| 438 | // See Effective Java, Second Ed., Item 78. | ||
| 439 | private void readObject(java.io.ObjectInputStream stream) | ||
| 440 | throws java.io.InvalidObjectException { | ||
| 441 | throw new java.io.InvalidObjectException("Proxy required"); | ||
| 442 | } | ||
| 443 | } | ||