1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 | /* * Copyright (c) 1997, 2023, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package Torello.Java.ReadOnly; import Torello.Java.Additional.RemoveUnsupportedIterator; import java.util.*; import java.util.function.Predicate; /** * A Copy of Java's {@code HashSet} class; used for building a {@link ReadOnlyHashSet}. Maintains * <I>an internal and inaccessible {@code HashSet<E>} instance</I>. * * <EMBED CLASS=globalDefs DATA-JDK=HashSet> * <EMBED CLASS='external-html' DATA-A_AN=a DATA-FILE-ID=BUILDERS> * * @param <E> the type of elements maintained by this set * @see ReadOnlyHashSet */ @Torello.JavaDoc.JDHeaderBackgroundImg(EmbedTagFileID="JDHBI_BUILDER") public final class ROHashSetBuilder<E> extends HashSet<E> implements Cloneable, java.io.Serializable { // ******************************************************************************************** // ******************************************************************************************** // Fields & Builder // ******************************************************************************************** // ******************************************************************************************** /** <EMBED CLASS='external-html' DATA-FILE-ID=SVUID> */ protected static final long serialVersionUID = 1; // Exception messages need this private static final String ROHS = "HashSet"; private boolean built = false; // Mimics the C++ Concept of "Friend Class". This badge is utilized by the "build()" method // directly below this inner-class declaration. It is the only place where this declaration is // actually used anywhere. This prohibits access to the constructor that is used to anybody // else static class AccessBadge { private AccessBadge() { } } private static final AccessBadge friendClassBadge = new AccessBadge(); /** * Simply transfers {@code 'this'} instance' internal {@code HashSet} to the * {@code ReadOnlyHashSet} Wrapper-Class. * * @return a newly constructed {@code ReadOnlyHashSet} "Wrapper-Class", shielding the * internal {@code 'hashSet'} private-field from any modification. */ public ReadOnlyHashSet<E> build() { this.built = true; return (size() == 0) ? ReadOnlyHashSet.emptyROHS() : new ReadOnlyHashSet<E>(this, friendClassBadge); } // ******************************************************************************************** // ******************************************************************************************** // Modified Constructors // ******************************************************************************************** // ******************************************************************************************** /** * Constructs a new, empty {@code ROHashSetBuilder}, the underlying {@code HashMap} instance * has default initial capacity (16) and load factor (0.75). */ public ROHashSetBuilder() { super(); } /** * Constructs a new {@code ROHashSetBuilder} containing the elements in the specified * collection. The underlying {@code HashMap} is created with default load factor (0.75) and * an initial capacity sufficient to contain the elements in the specified collection. * * @param c the collection whose elements are to be placed into this set * @throws NullPointerException if the specified collection is null */ public ROHashSetBuilder(Collection<? extends E> c) { super(c); } /** * Constructs a new, empty {@code ROHashSetBuilder}; the backing {@code HashMap} instance has * the specified initial capacity and the specified load factor. * * <BR /><BR />To create a {@code ROHashSetBuilder} with an initial capacity that accommodates * an expected number of elements, use {@link #newROHashSetBuilder(int) newROHashSetBuilder}. * * @param initialCapacity the initial capacity of the hash map * @param loadFactor the load factor of the hash map * * @throws IllegalArgumentException if the initial capacity is less than zero, or if the load * factor is nonpositive */ public ROHashSetBuilder(int initialCapacity, float loadFactor) { super(initialCapacity, loadFactor); } /** * Constructs a new, empty {@code ROHashSetBuilder}; the backing {@code HashMap} instance has * the specified initial capacity and default load factor (0.75). * * <BR /><BR />To create a {@code ReadOnlyHashSet} with an initial capacity that accommodates * an expected number of elements, use {@link #newROHashSetBuilder(int) newROHashSetBuilder}. * * @param initialCapacity the initial capacity of the hash table * @throws IllegalArgumentException if the initial capacity is less than zero */ public ROHashSetBuilder(int initialCapacity) { super(initialCapacity); } /** * Creates a new, empty {@code ROHashSetBuilder} suitable for the expected number of elements. * The returned set uses the default load factor of 0.75, and its initial capacity is generally * large enough so that the expected number of elements can be added without resizing the set. * * @param <T> the type of elements maintained by the new set builder * @param numElements the expected number of elements * @return the newly created builder * @throws IllegalArgumentException if numElements is negative */ public static <T> ROHashSetBuilder<T> newROHashSetBuilder(int numElements) { if (numElements < 0) throw new IllegalArgumentException("Negative number of elements: " + numElements); return new ROHashSetBuilder<>(calculateHashMapCapacity(numElements)); } // Copied from JDK-21, java.util.HashMap // Calculate initial capacity for HashMap based classes, from expected size and default load // factor (0.75). private static int calculateHashMapCapacity(int numMappings) { return (int) Math.ceil(numMappings / (double) /* DEFAULT_LOAD_FACTOR */ 0.75f); } // ******************************************************************************************** // ******************************************************************************************** // Original JDK Methods // ******************************************************************************************** // ******************************************************************************************** public RemoveUnsupportedIterator<E> iterator() { return new RemoveUnsupportedIterator<>(super.iterator()); } /** * Adds the specified element to this set if it is not already present. More formally, adds * the specified element {@code e} to this set if this set contains no element {@code e2} such * that {@code Objects.equals(e, e2)}. If this set already contains the element, the call * leaves the set unchanged and returns {@code FALSE}. * * <EMBED DATA-TYPE=HashSet CLASS='external-html' DATA-FILE-ID=MUTATOR> * * @param e element to be added to this set * @return {@code TRUE} if this set did not already contain the specified element */ public boolean add(E e) { if (this.built) throw new AttemptedModificationException(ROHS); return super.add(e); } /** * Removes the specified element from this set if it is present. More formally, removes an * element {@code e} such that {@code Objects.equals(o, e)}, if this set contains such an * element. Returns {@code TRUE} if this set contained the element (or equivalently, if this * set changed as a result of the call). (This set will not contain the element once the call * returns.) * * <EMBED DATA-TYPE=HashSet CLASS='external-html' DATA-FILE-ID=MUTATOR> * * @param o object to be removed from this set, if present * @return {@code TRUE} if the set contained the specified element */ public boolean remove(Object o) { if (this.built) throw new AttemptedModificationException(ROHS); return super.remove(o); } /** * Removes all of the elements from this set. The set will be empty after this call returns. * <EMBED DATA-TYPE=HashSet CLASS='external-html' DATA-FILE-ID=MUTATOR> */ public void clear() { if (this.built) throw new AttemptedModificationException(ROHS); super.clear(); } // ******************************************************************************************** // ******************************************************************************************** // Methods inherited from class java.util.HashSet // ******************************************************************************************** // ******************************************************************************************** // contains, isEmpty, size, spliterator // // Introspection Only: contains, isEmpty, size, spliterator // Mutator or Potential Mutator Methods: NONE // // *** OTHER INHERITED METHODS *** // // Methods inherited from class java.util.AbstractSet: // hashCode, removeAll // // Methods inherited from class java.util.AbstractCollection: // addAll, containsAll, retainAll, toArray, toArray, toString // // Methods inherited from interface java.util.Collection: // parallelStream, removeIf, stream, toArray // // Methods inherited from interface java.lang.Iterable: // forEach // // Methods inherited from interface java.util.Set: // addAll, containsAll, hashCode, removeAll, retainAll, toArray, toArray @Override public boolean removeAll(Collection<?> c) { if (this.built) throw new AttemptedModificationException(ROHS); return super.removeAll(c); } @Override public boolean addAll(Collection<? extends E> c) { if (this.built) throw new AttemptedModificationException(ROHS); return super.addAll(c); } @Override public boolean retainAll(Collection<?> c) { if (this.built) throw new AttemptedModificationException(ROHS); return super.retainAll(c); } @Override public boolean removeIf(Predicate<? super E> filter) { if (this.built) throw new AttemptedModificationException(ROHS); return super.removeIf(filter); } // ******************************************************************************************** // ******************************************************************************************** // java.lang.Object & Cloneable // ******************************************************************************************** // ******************************************************************************************** /** * Compares the specified Object with this Builder for equality, as per the definition in the * original class {@code java.util.HashSet}. Ignores the private field {@code 'built'}. If * {@code 'this'} has not been built, but {@code 'o'} has been, that fact is ignored during the * equality-comparison. * * @param o object to be compared for equality with this {@code ROHashSetBuilder} instance * @return true if the specified Object is equal to this Builder */ public boolean equals(Object o) { if (this == o) return true; if (! (o instanceof ROHashSetBuilder)) return false; return super.equals((HashSet) o); } /** * Clones this instance' of {@code ROHashSetBuilder}. * * <BR /><BR />The clone that's returned has had it's internal {@code 'built'} boolean-flag set * {@code FALSE} * * @return a clone of this builder */ public synchronized ROHashSetBuilder<E> clone() { return new ROHashSetBuilder<>(this); } private ROHashSetBuilder(ROHashSetBuilder<E> rohsb) { super(rohsb); this.built=false; } } |