Shuyi Chen | d7955ce | 2013-05-22 14:51:55 -0700 | [diff] [blame] | 1 | // GenericsNote: Converted -- However, null keys will now be represented in the internal structures, a big change. |
| 2 | /* |
| 3 | * Copyright 2003-2004 The Apache Software Foundation |
| 4 | * |
| 5 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 6 | * you may not use this file except in compliance with the License. |
| 7 | * You may obtain a copy of the License at |
| 8 | * |
| 9 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 10 | * |
| 11 | * Unless required by applicable law or agreed to in writing, software |
| 12 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 13 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 14 | * See the License for the specific language governing permissions and |
| 15 | * limitations under the License. |
| 16 | */ |
| 17 | package org.jivesoftware.smack.util.collections; |
| 18 | |
| 19 | import java.io.IOException; |
| 20 | import java.io.ObjectInputStream; |
| 21 | import java.io.ObjectOutputStream; |
| 22 | import java.util.*; |
| 23 | |
| 24 | /** |
| 25 | * An abstract implementation of a hash-based map which provides numerous points for |
| 26 | * subclasses to override. |
| 27 | * <p/> |
| 28 | * This class implements all the features necessary for a subclass hash-based map. |
| 29 | * Key-value entries are stored in instances of the <code>HashEntry</code> class, |
| 30 | * which can be overridden and replaced. The iterators can similarly be replaced, |
| 31 | * without the need to replace the KeySet, EntrySet and Values view classes. |
| 32 | * <p/> |
| 33 | * Overridable methods are provided to change the default hashing behaviour, and |
| 34 | * to change how entries are added to and removed from the map. Hopefully, all you |
| 35 | * need for unusual subclasses is here. |
| 36 | * <p/> |
| 37 | * NOTE: From Commons Collections 3.1 this class extends AbstractMap. |
| 38 | * This is to provide backwards compatibility for ReferenceMap between v3.0 and v3.1. |
| 39 | * This extends clause will be removed in v4.0. |
| 40 | * |
| 41 | * @author java util HashMap |
| 42 | * @author Matt Hall, John Watkinson, Stephen Colebourne |
| 43 | * @version $Revision: 1.1 $ $Date: 2005/10/11 17:05:32 $ |
| 44 | * @since Commons Collections 3.0 |
| 45 | */ |
| 46 | public class AbstractHashedMap <K,V> extends AbstractMap<K, V> implements IterableMap<K, V> { |
| 47 | |
| 48 | protected static final String NO_NEXT_ENTRY = "No next() entry in the iteration"; |
| 49 | protected static final String NO_PREVIOUS_ENTRY = "No previous() entry in the iteration"; |
| 50 | protected static final String REMOVE_INVALID = "remove() can only be called once after next()"; |
| 51 | protected static final String GETKEY_INVALID = "getKey() can only be called after next() and before remove()"; |
| 52 | protected static final String GETVALUE_INVALID = "getValue() can only be called after next() and before remove()"; |
| 53 | protected static final String SETVALUE_INVALID = "setValue() can only be called after next() and before remove()"; |
| 54 | |
| 55 | /** |
| 56 | * The default capacity to use |
| 57 | */ |
| 58 | protected static final int DEFAULT_CAPACITY = 16; |
| 59 | /** |
| 60 | * The default threshold to use |
| 61 | */ |
| 62 | protected static final int DEFAULT_THRESHOLD = 12; |
| 63 | /** |
| 64 | * The default load factor to use |
| 65 | */ |
| 66 | protected static final float DEFAULT_LOAD_FACTOR = 0.75f; |
| 67 | /** |
| 68 | * The maximum capacity allowed |
| 69 | */ |
| 70 | protected static final int MAXIMUM_CAPACITY = 1 << 30; |
| 71 | /** |
| 72 | * An object for masking null |
| 73 | */ |
| 74 | protected static final Object NULL = new Object(); |
| 75 | |
| 76 | /** |
| 77 | * Load factor, normally 0.75 |
| 78 | */ |
| 79 | protected transient float loadFactor; |
| 80 | /** |
| 81 | * The size of the map |
| 82 | */ |
| 83 | protected transient int size; |
| 84 | /** |
| 85 | * Map entries |
| 86 | */ |
| 87 | protected transient HashEntry<K, V>[] data; |
| 88 | /** |
| 89 | * Size at which to rehash |
| 90 | */ |
| 91 | protected transient int threshold; |
| 92 | /** |
| 93 | * Modification count for iterators |
| 94 | */ |
| 95 | protected transient int modCount; |
| 96 | /** |
| 97 | * Entry set |
| 98 | */ |
| 99 | protected transient EntrySet<K, V> entrySet; |
| 100 | /** |
| 101 | * Key set |
| 102 | */ |
| 103 | protected transient KeySet<K, V> keySet; |
| 104 | /** |
| 105 | * Values |
| 106 | */ |
| 107 | protected transient Values<K, V> values; |
| 108 | |
| 109 | /** |
| 110 | * Constructor only used in deserialization, do not use otherwise. |
| 111 | */ |
| 112 | protected AbstractHashedMap() { |
| 113 | super(); |
| 114 | } |
| 115 | |
| 116 | /** |
| 117 | * Constructor which performs no validation on the passed in parameters. |
| 118 | * |
| 119 | * @param initialCapacity the initial capacity, must be a power of two |
| 120 | * @param loadFactor the load factor, must be > 0.0f and generally < 1.0f |
| 121 | * @param threshold the threshold, must be sensible |
| 122 | */ |
| 123 | protected AbstractHashedMap(int initialCapacity, float loadFactor, int threshold) { |
| 124 | super(); |
| 125 | this.loadFactor = loadFactor; |
| 126 | this.data = new HashEntry[initialCapacity]; |
| 127 | this.threshold = threshold; |
| 128 | init(); |
| 129 | } |
| 130 | |
| 131 | /** |
| 132 | * Constructs a new, empty map with the specified initial capacity and |
| 133 | * default load factor. |
| 134 | * |
| 135 | * @param initialCapacity the initial capacity |
| 136 | * @throws IllegalArgumentException if the initial capacity is less than one |
| 137 | */ |
| 138 | protected AbstractHashedMap(int initialCapacity) { |
| 139 | this(initialCapacity, DEFAULT_LOAD_FACTOR); |
| 140 | } |
| 141 | |
| 142 | /** |
| 143 | * Constructs a new, empty map with the specified initial capacity and |
| 144 | * load factor. |
| 145 | * |
| 146 | * @param initialCapacity the initial capacity |
| 147 | * @param loadFactor the load factor |
| 148 | * @throws IllegalArgumentException if the initial capacity is less than one |
| 149 | * @throws IllegalArgumentException if the load factor is less than or equal to zero |
| 150 | */ |
| 151 | protected AbstractHashedMap(int initialCapacity, float loadFactor) { |
| 152 | super(); |
| 153 | if (initialCapacity < 1) { |
| 154 | throw new IllegalArgumentException("Initial capacity must be greater than 0"); |
| 155 | } |
| 156 | if (loadFactor <= 0.0f || Float.isNaN(loadFactor)) { |
| 157 | throw new IllegalArgumentException("Load factor must be greater than 0"); |
| 158 | } |
| 159 | this.loadFactor = loadFactor; |
| 160 | this.threshold = calculateThreshold(initialCapacity, loadFactor); |
| 161 | initialCapacity = calculateNewCapacity(initialCapacity); |
| 162 | this.data = new HashEntry[initialCapacity]; |
| 163 | init(); |
| 164 | } |
| 165 | |
| 166 | /** |
| 167 | * Constructor copying elements from another map. |
| 168 | * |
| 169 | * @param map the map to copy |
| 170 | * @throws NullPointerException if the map is null |
| 171 | */ |
| 172 | protected AbstractHashedMap(Map<? extends K, ? extends V> map) { |
| 173 | this(Math.max(2 * map.size(), DEFAULT_CAPACITY), DEFAULT_LOAD_FACTOR); |
| 174 | putAll(map); |
| 175 | } |
| 176 | |
| 177 | /** |
| 178 | * Initialise subclasses during construction, cloning or deserialization. |
| 179 | */ |
| 180 | protected void init() { |
| 181 | } |
| 182 | |
| 183 | //----------------------------------------------------------------------- |
| 184 | /** |
| 185 | * Gets the value mapped to the key specified. |
| 186 | * |
| 187 | * @param key the key |
| 188 | * @return the mapped value, null if no match |
| 189 | */ |
| 190 | public V get(Object key) { |
| 191 | int hashCode = hash((key == null) ? NULL : key); |
| 192 | HashEntry<K, V> entry = data[hashIndex(hashCode, data.length)]; // no local for hash index |
| 193 | while (entry != null) { |
| 194 | if (entry.hashCode == hashCode && isEqualKey(key, entry.key)) { |
| 195 | return entry.getValue(); |
| 196 | } |
| 197 | entry = entry.next; |
| 198 | } |
| 199 | return null; |
| 200 | } |
| 201 | |
| 202 | /** |
| 203 | * Gets the size of the map. |
| 204 | * |
| 205 | * @return the size |
| 206 | */ |
| 207 | public int size() { |
| 208 | return size; |
| 209 | } |
| 210 | |
| 211 | /** |
| 212 | * Checks whether the map is currently empty. |
| 213 | * |
| 214 | * @return true if the map is currently size zero |
| 215 | */ |
| 216 | public boolean isEmpty() { |
| 217 | return (size == 0); |
| 218 | } |
| 219 | |
| 220 | //----------------------------------------------------------------------- |
| 221 | /** |
| 222 | * Checks whether the map contains the specified key. |
| 223 | * |
| 224 | * @param key the key to search for |
| 225 | * @return true if the map contains the key |
| 226 | */ |
| 227 | public boolean containsKey(Object key) { |
| 228 | int hashCode = hash((key == null) ? NULL : key); |
| 229 | HashEntry entry = data[hashIndex(hashCode, data.length)]; // no local for hash index |
| 230 | while (entry != null) { |
| 231 | if (entry.hashCode == hashCode && isEqualKey(key, entry.getKey())) { |
| 232 | return true; |
| 233 | } |
| 234 | entry = entry.next; |
| 235 | } |
| 236 | return false; |
| 237 | } |
| 238 | |
| 239 | /** |
| 240 | * Checks whether the map contains the specified value. |
| 241 | * |
| 242 | * @param value the value to search for |
| 243 | * @return true if the map contains the value |
| 244 | */ |
| 245 | public boolean containsValue(Object value) { |
| 246 | if (value == null) { |
| 247 | for (int i = 0, isize = data.length; i < isize; i++) { |
| 248 | HashEntry entry = data[i]; |
| 249 | while (entry != null) { |
| 250 | if (entry.getValue() == null) { |
| 251 | return true; |
| 252 | } |
| 253 | entry = entry.next; |
| 254 | } |
| 255 | } |
| 256 | } else { |
| 257 | for (int i = 0, isize = data.length; i < isize; i++) { |
| 258 | HashEntry entry = data[i]; |
| 259 | while (entry != null) { |
| 260 | if (isEqualValue(value, entry.getValue())) { |
| 261 | return true; |
| 262 | } |
| 263 | entry = entry.next; |
| 264 | } |
| 265 | } |
| 266 | } |
| 267 | return false; |
| 268 | } |
| 269 | |
| 270 | //----------------------------------------------------------------------- |
| 271 | /** |
| 272 | * Puts a key-value mapping into this map. |
| 273 | * |
| 274 | * @param key the key to add |
| 275 | * @param value the value to add |
| 276 | * @return the value previously mapped to this key, null if none |
| 277 | */ |
| 278 | public V put(K key, V value) { |
| 279 | int hashCode = hash((key == null) ? NULL : key); |
| 280 | int index = hashIndex(hashCode, data.length); |
| 281 | HashEntry<K, V> entry = data[index]; |
| 282 | while (entry != null) { |
| 283 | if (entry.hashCode == hashCode && isEqualKey(key, entry.getKey())) { |
| 284 | V oldValue = entry.getValue(); |
| 285 | updateEntry(entry, value); |
| 286 | return oldValue; |
| 287 | } |
| 288 | entry = entry.next; |
| 289 | } |
| 290 | addMapping(index, hashCode, key, value); |
| 291 | return null; |
| 292 | } |
| 293 | |
| 294 | /** |
| 295 | * Puts all the values from the specified map into this map. |
| 296 | * <p/> |
| 297 | * This implementation iterates around the specified map and |
| 298 | * uses {@link #put(Object, Object)}. |
| 299 | * |
| 300 | * @param map the map to add |
| 301 | * @throws NullPointerException if the map is null |
| 302 | */ |
| 303 | public void putAll(Map<? extends K, ? extends V> map) { |
| 304 | int mapSize = map.size(); |
| 305 | if (mapSize == 0) { |
| 306 | return; |
| 307 | } |
| 308 | int newSize = (int) ((size + mapSize) / loadFactor + 1); |
| 309 | ensureCapacity(calculateNewCapacity(newSize)); |
| 310 | // Have to cast here because of compiler inference problems. |
| 311 | for (Iterator it = map.entrySet().iterator(); it.hasNext();) { |
| 312 | Map.Entry<? extends K, ? extends V> entry = (Map.Entry<? extends K, ? extends V>) it.next(); |
| 313 | put(entry.getKey(), entry.getValue()); |
| 314 | } |
| 315 | } |
| 316 | |
| 317 | /** |
| 318 | * Removes the specified mapping from this map. |
| 319 | * |
| 320 | * @param key the mapping to remove |
| 321 | * @return the value mapped to the removed key, null if key not in map |
| 322 | */ |
| 323 | public V remove(Object key) { |
| 324 | int hashCode = hash((key == null) ? NULL : key); |
| 325 | int index = hashIndex(hashCode, data.length); |
| 326 | HashEntry<K, V> entry = data[index]; |
| 327 | HashEntry<K, V> previous = null; |
| 328 | while (entry != null) { |
| 329 | if (entry.hashCode == hashCode && isEqualKey(key, entry.getKey())) { |
| 330 | V oldValue = entry.getValue(); |
| 331 | removeMapping(entry, index, previous); |
| 332 | return oldValue; |
| 333 | } |
| 334 | previous = entry; |
| 335 | entry = entry.next; |
| 336 | } |
| 337 | return null; |
| 338 | } |
| 339 | |
| 340 | /** |
| 341 | * Clears the map, resetting the size to zero and nullifying references |
| 342 | * to avoid garbage collection issues. |
| 343 | */ |
| 344 | public void clear() { |
| 345 | modCount++; |
| 346 | HashEntry[] data = this.data; |
| 347 | for (int i = data.length - 1; i >= 0; i--) { |
| 348 | data[i] = null; |
| 349 | } |
| 350 | size = 0; |
| 351 | } |
| 352 | |
| 353 | /** |
| 354 | * Gets the hash code for the key specified. |
| 355 | * This implementation uses the additional hashing routine from JDK1.4. |
| 356 | * Subclasses can override this to return alternate hash codes. |
| 357 | * |
| 358 | * @param key the key to get a hash code for |
| 359 | * @return the hash code |
| 360 | */ |
| 361 | protected int hash(Object key) { |
| 362 | // same as JDK 1.4 |
| 363 | int h = key.hashCode(); |
| 364 | h += ~(h << 9); |
| 365 | h ^= (h >>> 14); |
| 366 | h += (h << 4); |
| 367 | h ^= (h >>> 10); |
| 368 | return h; |
| 369 | } |
| 370 | |
| 371 | /** |
| 372 | * Compares two keys, in internal converted form, to see if they are equal. |
| 373 | * This implementation uses the equals method. |
| 374 | * Subclasses can override this to match differently. |
| 375 | * |
| 376 | * @param key1 the first key to compare passed in from outside |
| 377 | * @param key2 the second key extracted from the entry via <code>entry.key</code> |
| 378 | * @return true if equal |
| 379 | */ |
| 380 | protected boolean isEqualKey(Object key1, Object key2) { |
| 381 | return (key1 == key2 || ((key1 != null) && key1.equals(key2))); |
| 382 | } |
| 383 | |
| 384 | /** |
| 385 | * Compares two values, in external form, to see if they are equal. |
| 386 | * This implementation uses the equals method and assumes neither value is null. |
| 387 | * Subclasses can override this to match differently. |
| 388 | * |
| 389 | * @param value1 the first value to compare passed in from outside |
| 390 | * @param value2 the second value extracted from the entry via <code>getValue()</code> |
| 391 | * @return true if equal |
| 392 | */ |
| 393 | protected boolean isEqualValue(Object value1, Object value2) { |
| 394 | return (value1 == value2 || value1.equals(value2)); |
| 395 | } |
| 396 | |
| 397 | /** |
| 398 | * Gets the index into the data storage for the hashCode specified. |
| 399 | * This implementation uses the least significant bits of the hashCode. |
| 400 | * Subclasses can override this to return alternate bucketing. |
| 401 | * |
| 402 | * @param hashCode the hash code to use |
| 403 | * @param dataSize the size of the data to pick a bucket from |
| 404 | * @return the bucket index |
| 405 | */ |
| 406 | protected int hashIndex(int hashCode, int dataSize) { |
| 407 | return hashCode & (dataSize - 1); |
| 408 | } |
| 409 | |
| 410 | //----------------------------------------------------------------------- |
| 411 | /** |
| 412 | * Gets the entry mapped to the key specified. |
| 413 | * <p/> |
| 414 | * This method exists for subclasses that may need to perform a multi-step |
| 415 | * process accessing the entry. The public methods in this class don't use this |
| 416 | * method to gain a small performance boost. |
| 417 | * |
| 418 | * @param key the key |
| 419 | * @return the entry, null if no match |
| 420 | */ |
| 421 | protected HashEntry<K, V> getEntry(Object key) { |
| 422 | int hashCode = hash((key == null) ? NULL : key); |
| 423 | HashEntry<K, V> entry = data[hashIndex(hashCode, data.length)]; // no local for hash index |
| 424 | while (entry != null) { |
| 425 | if (entry.hashCode == hashCode && isEqualKey(key, entry.getKey())) { |
| 426 | return entry; |
| 427 | } |
| 428 | entry = entry.next; |
| 429 | } |
| 430 | return null; |
| 431 | } |
| 432 | |
| 433 | //----------------------------------------------------------------------- |
| 434 | /** |
| 435 | * Updates an existing key-value mapping to change the value. |
| 436 | * <p/> |
| 437 | * This implementation calls <code>setValue()</code> on the entry. |
| 438 | * Subclasses could override to handle changes to the map. |
| 439 | * |
| 440 | * @param entry the entry to update |
| 441 | * @param newValue the new value to store |
| 442 | */ |
| 443 | protected void updateEntry(HashEntry<K, V> entry, V newValue) { |
| 444 | entry.setValue(newValue); |
| 445 | } |
| 446 | |
| 447 | /** |
| 448 | * Reuses an existing key-value mapping, storing completely new data. |
| 449 | * <p/> |
| 450 | * This implementation sets all the data fields on the entry. |
| 451 | * Subclasses could populate additional entry fields. |
| 452 | * |
| 453 | * @param entry the entry to update, not null |
| 454 | * @param hashIndex the index in the data array |
| 455 | * @param hashCode the hash code of the key to add |
| 456 | * @param key the key to add |
| 457 | * @param value the value to add |
| 458 | */ |
| 459 | protected void reuseEntry(HashEntry<K, V> entry, int hashIndex, int hashCode, K key, V value) { |
| 460 | entry.next = data[hashIndex]; |
| 461 | entry.hashCode = hashCode; |
| 462 | entry.key = key; |
| 463 | entry.value = value; |
| 464 | } |
| 465 | |
| 466 | //----------------------------------------------------------------------- |
| 467 | /** |
| 468 | * Adds a new key-value mapping into this map. |
| 469 | * <p/> |
| 470 | * This implementation calls <code>createEntry()</code>, <code>addEntry()</code> |
| 471 | * and <code>checkCapacity()</code>. |
| 472 | * It also handles changes to <code>modCount</code> and <code>size</code>. |
| 473 | * Subclasses could override to fully control adds to the map. |
| 474 | * |
| 475 | * @param hashIndex the index into the data array to store at |
| 476 | * @param hashCode the hash code of the key to add |
| 477 | * @param key the key to add |
| 478 | * @param value the value to add |
| 479 | */ |
| 480 | protected void addMapping(int hashIndex, int hashCode, K key, V value) { |
| 481 | modCount++; |
| 482 | HashEntry<K, V> entry = createEntry(data[hashIndex], hashCode, key, value); |
| 483 | addEntry(entry, hashIndex); |
| 484 | size++; |
| 485 | checkCapacity(); |
| 486 | } |
| 487 | |
| 488 | /** |
| 489 | * Creates an entry to store the key-value data. |
| 490 | * <p/> |
| 491 | * This implementation creates a new HashEntry instance. |
| 492 | * Subclasses can override this to return a different storage class, |
| 493 | * or implement caching. |
| 494 | * |
| 495 | * @param next the next entry in sequence |
| 496 | * @param hashCode the hash code to use |
| 497 | * @param key the key to store |
| 498 | * @param value the value to store |
| 499 | * @return the newly created entry |
| 500 | */ |
| 501 | protected HashEntry<K, V> createEntry(HashEntry<K, V> next, int hashCode, K key, V value) { |
| 502 | return new HashEntry<K, V>(next, hashCode, key, value); |
| 503 | } |
| 504 | |
| 505 | /** |
| 506 | * Adds an entry into this map. |
| 507 | * <p/> |
| 508 | * This implementation adds the entry to the data storage table. |
| 509 | * Subclasses could override to handle changes to the map. |
| 510 | * |
| 511 | * @param entry the entry to add |
| 512 | * @param hashIndex the index into the data array to store at |
| 513 | */ |
| 514 | protected void addEntry(HashEntry<K, V> entry, int hashIndex) { |
| 515 | data[hashIndex] = entry; |
| 516 | } |
| 517 | |
| 518 | //----------------------------------------------------------------------- |
| 519 | /** |
| 520 | * Removes a mapping from the map. |
| 521 | * <p/> |
| 522 | * This implementation calls <code>removeEntry()</code> and <code>destroyEntry()</code>. |
| 523 | * It also handles changes to <code>modCount</code> and <code>size</code>. |
| 524 | * Subclasses could override to fully control removals from the map. |
| 525 | * |
| 526 | * @param entry the entry to remove |
| 527 | * @param hashIndex the index into the data structure |
| 528 | * @param previous the previous entry in the chain |
| 529 | */ |
| 530 | protected void removeMapping(HashEntry<K, V> entry, int hashIndex, HashEntry<K, V> previous) { |
| 531 | modCount++; |
| 532 | removeEntry(entry, hashIndex, previous); |
| 533 | size--; |
| 534 | destroyEntry(entry); |
| 535 | } |
| 536 | |
| 537 | /** |
| 538 | * Removes an entry from the chain stored in a particular index. |
| 539 | * <p/> |
| 540 | * This implementation removes the entry from the data storage table. |
| 541 | * The size is not updated. |
| 542 | * Subclasses could override to handle changes to the map. |
| 543 | * |
| 544 | * @param entry the entry to remove |
| 545 | * @param hashIndex the index into the data structure |
| 546 | * @param previous the previous entry in the chain |
| 547 | */ |
| 548 | protected void removeEntry(HashEntry<K, V> entry, int hashIndex, HashEntry<K, V> previous) { |
| 549 | if (previous == null) { |
| 550 | data[hashIndex] = entry.next; |
| 551 | } else { |
| 552 | previous.next = entry.next; |
| 553 | } |
| 554 | } |
| 555 | |
| 556 | /** |
| 557 | * Kills an entry ready for the garbage collector. |
| 558 | * <p/> |
| 559 | * This implementation prepares the HashEntry for garbage collection. |
| 560 | * Subclasses can override this to implement caching (override clear as well). |
| 561 | * |
| 562 | * @param entry the entry to destroy |
| 563 | */ |
| 564 | protected void destroyEntry(HashEntry<K, V> entry) { |
| 565 | entry.next = null; |
| 566 | entry.key = null; |
| 567 | entry.value = null; |
| 568 | } |
| 569 | |
| 570 | //----------------------------------------------------------------------- |
| 571 | /** |
| 572 | * Checks the capacity of the map and enlarges it if necessary. |
| 573 | * <p/> |
| 574 | * This implementation uses the threshold to check if the map needs enlarging |
| 575 | */ |
| 576 | protected void checkCapacity() { |
| 577 | if (size >= threshold) { |
| 578 | int newCapacity = data.length * 2; |
| 579 | if (newCapacity <= MAXIMUM_CAPACITY) { |
| 580 | ensureCapacity(newCapacity); |
| 581 | } |
| 582 | } |
| 583 | } |
| 584 | |
| 585 | /** |
| 586 | * Changes the size of the data structure to the capacity proposed. |
| 587 | * |
| 588 | * @param newCapacity the new capacity of the array (a power of two, less or equal to max) |
| 589 | */ |
| 590 | protected void ensureCapacity(int newCapacity) { |
| 591 | int oldCapacity = data.length; |
| 592 | if (newCapacity <= oldCapacity) { |
| 593 | return; |
| 594 | } |
| 595 | if (size == 0) { |
| 596 | threshold = calculateThreshold(newCapacity, loadFactor); |
| 597 | data = new HashEntry[newCapacity]; |
| 598 | } else { |
| 599 | HashEntry<K, V> oldEntries[] = data; |
| 600 | HashEntry<K, V> newEntries[] = new HashEntry[newCapacity]; |
| 601 | |
| 602 | modCount++; |
| 603 | for (int i = oldCapacity - 1; i >= 0; i--) { |
| 604 | HashEntry<K, V> entry = oldEntries[i]; |
| 605 | if (entry != null) { |
| 606 | oldEntries[i] = null; // gc |
| 607 | do { |
| 608 | HashEntry<K, V> next = entry.next; |
| 609 | int index = hashIndex(entry.hashCode, newCapacity); |
| 610 | entry.next = newEntries[index]; |
| 611 | newEntries[index] = entry; |
| 612 | entry = next; |
| 613 | } while (entry != null); |
| 614 | } |
| 615 | } |
| 616 | threshold = calculateThreshold(newCapacity, loadFactor); |
| 617 | data = newEntries; |
| 618 | } |
| 619 | } |
| 620 | |
| 621 | /** |
| 622 | * Calculates the new capacity of the map. |
| 623 | * This implementation normalizes the capacity to a power of two. |
| 624 | * |
| 625 | * @param proposedCapacity the proposed capacity |
| 626 | * @return the normalized new capacity |
| 627 | */ |
| 628 | protected int calculateNewCapacity(int proposedCapacity) { |
| 629 | int newCapacity = 1; |
| 630 | if (proposedCapacity > MAXIMUM_CAPACITY) { |
| 631 | newCapacity = MAXIMUM_CAPACITY; |
| 632 | } else { |
| 633 | while (newCapacity < proposedCapacity) { |
| 634 | newCapacity <<= 1; // multiply by two |
| 635 | } |
| 636 | if (newCapacity > MAXIMUM_CAPACITY) { |
| 637 | newCapacity = MAXIMUM_CAPACITY; |
| 638 | } |
| 639 | } |
| 640 | return newCapacity; |
| 641 | } |
| 642 | |
| 643 | /** |
| 644 | * Calculates the new threshold of the map, where it will be resized. |
| 645 | * This implementation uses the load factor. |
| 646 | * |
| 647 | * @param newCapacity the new capacity |
| 648 | * @param factor the load factor |
| 649 | * @return the new resize threshold |
| 650 | */ |
| 651 | protected int calculateThreshold(int newCapacity, float factor) { |
| 652 | return (int) (newCapacity * factor); |
| 653 | } |
| 654 | |
| 655 | //----------------------------------------------------------------------- |
| 656 | /** |
| 657 | * Gets the <code>next</code> field from a <code>HashEntry</code>. |
| 658 | * Used in subclasses that have no visibility of the field. |
| 659 | * |
| 660 | * @param entry the entry to query, must not be null |
| 661 | * @return the <code>next</code> field of the entry |
| 662 | * @throws NullPointerException if the entry is null |
| 663 | * @since Commons Collections 3.1 |
| 664 | */ |
| 665 | protected HashEntry<K, V> entryNext(HashEntry<K, V> entry) { |
| 666 | return entry.next; |
| 667 | } |
| 668 | |
| 669 | /** |
| 670 | * Gets the <code>hashCode</code> field from a <code>HashEntry</code>. |
| 671 | * Used in subclasses that have no visibility of the field. |
| 672 | * |
| 673 | * @param entry the entry to query, must not be null |
| 674 | * @return the <code>hashCode</code> field of the entry |
| 675 | * @throws NullPointerException if the entry is null |
| 676 | * @since Commons Collections 3.1 |
| 677 | */ |
| 678 | protected int entryHashCode(HashEntry<K, V> entry) { |
| 679 | return entry.hashCode; |
| 680 | } |
| 681 | |
| 682 | /** |
| 683 | * Gets the <code>key</code> field from a <code>HashEntry</code>. |
| 684 | * Used in subclasses that have no visibility of the field. |
| 685 | * |
| 686 | * @param entry the entry to query, must not be null |
| 687 | * @return the <code>key</code> field of the entry |
| 688 | * @throws NullPointerException if the entry is null |
| 689 | * @since Commons Collections 3.1 |
| 690 | */ |
| 691 | protected K entryKey(HashEntry<K, V> entry) { |
| 692 | return entry.key; |
| 693 | } |
| 694 | |
| 695 | /** |
| 696 | * Gets the <code>value</code> field from a <code>HashEntry</code>. |
| 697 | * Used in subclasses that have no visibility of the field. |
| 698 | * |
| 699 | * @param entry the entry to query, must not be null |
| 700 | * @return the <code>value</code> field of the entry |
| 701 | * @throws NullPointerException if the entry is null |
| 702 | * @since Commons Collections 3.1 |
| 703 | */ |
| 704 | protected V entryValue(HashEntry<K, V> entry) { |
| 705 | return entry.value; |
| 706 | } |
| 707 | |
| 708 | //----------------------------------------------------------------------- |
| 709 | /** |
| 710 | * Gets an iterator over the map. |
| 711 | * Changes made to the iterator affect this map. |
| 712 | * <p/> |
| 713 | * A MapIterator returns the keys in the map. It also provides convenient |
| 714 | * methods to get the key and value, and set the value. |
| 715 | * It avoids the need to create an entrySet/keySet/values object. |
| 716 | * It also avoids creating the Map.Entry object. |
| 717 | * |
| 718 | * @return the map iterator |
| 719 | */ |
| 720 | public MapIterator<K, V> mapIterator() { |
| 721 | if (size == 0) { |
| 722 | return EmptyMapIterator.INSTANCE; |
| 723 | } |
| 724 | return new HashMapIterator<K, V>(this); |
| 725 | } |
| 726 | |
| 727 | /** |
| 728 | * MapIterator implementation. |
| 729 | */ |
| 730 | protected static class HashMapIterator <K,V> extends HashIterator<K, V> implements MapIterator<K, V> { |
| 731 | |
| 732 | protected HashMapIterator(AbstractHashedMap<K, V> parent) { |
| 733 | super(parent); |
| 734 | } |
| 735 | |
| 736 | public K next() { |
| 737 | return super.nextEntry().getKey(); |
| 738 | } |
| 739 | |
| 740 | public K getKey() { |
| 741 | HashEntry<K, V> current = currentEntry(); |
| 742 | if (current == null) { |
| 743 | throw new IllegalStateException(AbstractHashedMap.GETKEY_INVALID); |
| 744 | } |
| 745 | return current.getKey(); |
| 746 | } |
| 747 | |
| 748 | public V getValue() { |
| 749 | HashEntry<K, V> current = currentEntry(); |
| 750 | if (current == null) { |
| 751 | throw new IllegalStateException(AbstractHashedMap.GETVALUE_INVALID); |
| 752 | } |
| 753 | return current.getValue(); |
| 754 | } |
| 755 | |
| 756 | public V setValue(V value) { |
| 757 | HashEntry<K, V> current = currentEntry(); |
| 758 | if (current == null) { |
| 759 | throw new IllegalStateException(AbstractHashedMap.SETVALUE_INVALID); |
| 760 | } |
| 761 | return current.setValue(value); |
| 762 | } |
| 763 | } |
| 764 | |
| 765 | //----------------------------------------------------------------------- |
| 766 | /** |
| 767 | * Gets the entrySet view of the map. |
| 768 | * Changes made to the view affect this map. |
| 769 | * To simply iterate through the entries, use {@link #mapIterator()}. |
| 770 | * |
| 771 | * @return the entrySet view |
| 772 | */ |
| 773 | public Set<Map.Entry<K, V>> entrySet() { |
| 774 | if (entrySet == null) { |
| 775 | entrySet = new EntrySet<K, V>(this); |
| 776 | } |
| 777 | return entrySet; |
| 778 | } |
| 779 | |
| 780 | /** |
| 781 | * Creates an entry set iterator. |
| 782 | * Subclasses can override this to return iterators with different properties. |
| 783 | * |
| 784 | * @return the entrySet iterator |
| 785 | */ |
| 786 | protected Iterator<Map.Entry<K, V>> createEntrySetIterator() { |
| 787 | if (size() == 0) { |
| 788 | return EmptyIterator.INSTANCE; |
| 789 | } |
| 790 | return new EntrySetIterator<K, V>(this); |
| 791 | } |
| 792 | |
| 793 | /** |
| 794 | * EntrySet implementation. |
| 795 | */ |
| 796 | protected static class EntrySet <K,V> extends AbstractSet<Map.Entry<K, V>> { |
| 797 | /** |
| 798 | * The parent map |
| 799 | */ |
| 800 | protected final AbstractHashedMap<K, V> parent; |
| 801 | |
| 802 | protected EntrySet(AbstractHashedMap<K, V> parent) { |
| 803 | super(); |
| 804 | this.parent = parent; |
| 805 | } |
| 806 | |
| 807 | public int size() { |
| 808 | return parent.size(); |
| 809 | } |
| 810 | |
| 811 | public void clear() { |
| 812 | parent.clear(); |
| 813 | } |
| 814 | |
| 815 | public boolean contains(Map.Entry<K, V> entry) { |
| 816 | Map.Entry<K, V> e = entry; |
| 817 | Entry<K, V> match = parent.getEntry(e.getKey()); |
| 818 | return (match != null && match.equals(e)); |
| 819 | } |
| 820 | |
| 821 | public boolean remove(Object obj) { |
| 822 | if (obj instanceof Map.Entry == false) { |
| 823 | return false; |
| 824 | } |
| 825 | if (contains(obj) == false) { |
| 826 | return false; |
| 827 | } |
| 828 | Map.Entry<K, V> entry = (Map.Entry<K, V>) obj; |
| 829 | K key = entry.getKey(); |
| 830 | parent.remove(key); |
| 831 | return true; |
| 832 | } |
| 833 | |
| 834 | public Iterator<Map.Entry<K, V>> iterator() { |
| 835 | return parent.createEntrySetIterator(); |
| 836 | } |
| 837 | } |
| 838 | |
| 839 | /** |
| 840 | * EntrySet iterator. |
| 841 | */ |
| 842 | protected static class EntrySetIterator <K,V> extends HashIterator<K, V> implements Iterator<Map.Entry<K, V>> { |
| 843 | |
| 844 | protected EntrySetIterator(AbstractHashedMap<K, V> parent) { |
| 845 | super(parent); |
| 846 | } |
| 847 | |
| 848 | public HashEntry<K, V> next() { |
| 849 | return super.nextEntry(); |
| 850 | } |
| 851 | } |
| 852 | |
| 853 | //----------------------------------------------------------------------- |
| 854 | /** |
| 855 | * Gets the keySet view of the map. |
| 856 | * Changes made to the view affect this map. |
| 857 | * To simply iterate through the keys, use {@link #mapIterator()}. |
| 858 | * |
| 859 | * @return the keySet view |
| 860 | */ |
| 861 | public Set<K> keySet() { |
| 862 | if (keySet == null) { |
| 863 | keySet = new KeySet<K, V>(this); |
| 864 | } |
| 865 | return keySet; |
| 866 | } |
| 867 | |
| 868 | /** |
| 869 | * Creates a key set iterator. |
| 870 | * Subclasses can override this to return iterators with different properties. |
| 871 | * |
| 872 | * @return the keySet iterator |
| 873 | */ |
| 874 | protected Iterator<K> createKeySetIterator() { |
| 875 | if (size() == 0) { |
| 876 | return EmptyIterator.INSTANCE; |
| 877 | } |
| 878 | return new KeySetIterator<K, V>(this); |
| 879 | } |
| 880 | |
| 881 | /** |
| 882 | * KeySet implementation. |
| 883 | */ |
| 884 | protected static class KeySet <K,V> extends AbstractSet<K> { |
| 885 | /** |
| 886 | * The parent map |
| 887 | */ |
| 888 | protected final AbstractHashedMap<K, V> parent; |
| 889 | |
| 890 | protected KeySet(AbstractHashedMap<K, V> parent) { |
| 891 | super(); |
| 892 | this.parent = parent; |
| 893 | } |
| 894 | |
| 895 | public int size() { |
| 896 | return parent.size(); |
| 897 | } |
| 898 | |
| 899 | public void clear() { |
| 900 | parent.clear(); |
| 901 | } |
| 902 | |
| 903 | public boolean contains(Object key) { |
| 904 | return parent.containsKey(key); |
| 905 | } |
| 906 | |
| 907 | public boolean remove(Object key) { |
| 908 | boolean result = parent.containsKey(key); |
| 909 | parent.remove(key); |
| 910 | return result; |
| 911 | } |
| 912 | |
| 913 | public Iterator<K> iterator() { |
| 914 | return parent.createKeySetIterator(); |
| 915 | } |
| 916 | } |
| 917 | |
| 918 | /** |
| 919 | * KeySet iterator. |
| 920 | */ |
| 921 | protected static class KeySetIterator <K,V> extends HashIterator<K, V> implements Iterator<K> { |
| 922 | |
| 923 | protected KeySetIterator(AbstractHashedMap<K, V> parent) { |
| 924 | super(parent); |
| 925 | } |
| 926 | |
| 927 | public K next() { |
| 928 | return super.nextEntry().getKey(); |
| 929 | } |
| 930 | } |
| 931 | |
| 932 | //----------------------------------------------------------------------- |
| 933 | /** |
| 934 | * Gets the values view of the map. |
| 935 | * Changes made to the view affect this map. |
| 936 | * To simply iterate through the values, use {@link #mapIterator()}. |
| 937 | * |
| 938 | * @return the values view |
| 939 | */ |
| 940 | public Collection<V> values() { |
| 941 | if (values == null) { |
| 942 | values = new Values(this); |
| 943 | } |
| 944 | return values; |
| 945 | } |
| 946 | |
| 947 | /** |
| 948 | * Creates a values iterator. |
| 949 | * Subclasses can override this to return iterators with different properties. |
| 950 | * |
| 951 | * @return the values iterator |
| 952 | */ |
| 953 | protected Iterator<V> createValuesIterator() { |
| 954 | if (size() == 0) { |
| 955 | return EmptyIterator.INSTANCE; |
| 956 | } |
| 957 | return new ValuesIterator<K, V>(this); |
| 958 | } |
| 959 | |
| 960 | /** |
| 961 | * Values implementation. |
| 962 | */ |
| 963 | protected static class Values <K,V> extends AbstractCollection<V> { |
| 964 | /** |
| 965 | * The parent map |
| 966 | */ |
| 967 | protected final AbstractHashedMap<K, V> parent; |
| 968 | |
| 969 | protected Values(AbstractHashedMap<K, V> parent) { |
| 970 | super(); |
| 971 | this.parent = parent; |
| 972 | } |
| 973 | |
| 974 | public int size() { |
| 975 | return parent.size(); |
| 976 | } |
| 977 | |
| 978 | public void clear() { |
| 979 | parent.clear(); |
| 980 | } |
| 981 | |
| 982 | public boolean contains(Object value) { |
| 983 | return parent.containsValue(value); |
| 984 | } |
| 985 | |
| 986 | public Iterator<V> iterator() { |
| 987 | return parent.createValuesIterator(); |
| 988 | } |
| 989 | } |
| 990 | |
| 991 | /** |
| 992 | * Values iterator. |
| 993 | */ |
| 994 | protected static class ValuesIterator <K,V> extends HashIterator<K, V> implements Iterator<V> { |
| 995 | |
| 996 | protected ValuesIterator(AbstractHashedMap<K, V> parent) { |
| 997 | super(parent); |
| 998 | } |
| 999 | |
| 1000 | public V next() { |
| 1001 | return super.nextEntry().getValue(); |
| 1002 | } |
| 1003 | } |
| 1004 | |
| 1005 | //----------------------------------------------------------------------- |
| 1006 | /** |
| 1007 | * HashEntry used to store the data. |
| 1008 | * <p/> |
| 1009 | * If you subclass <code>AbstractHashedMap</code> but not <code>HashEntry</code> |
| 1010 | * then you will not be able to access the protected fields. |
| 1011 | * The <code>entryXxx()</code> methods on <code>AbstractHashedMap</code> exist |
| 1012 | * to provide the necessary access. |
| 1013 | */ |
| 1014 | protected static class HashEntry <K,V> implements Map.Entry<K, V>, KeyValue<K, V> { |
| 1015 | /** |
| 1016 | * The next entry in the hash chain |
| 1017 | */ |
| 1018 | protected HashEntry<K, V> next; |
| 1019 | /** |
| 1020 | * The hash code of the key |
| 1021 | */ |
| 1022 | protected int hashCode; |
| 1023 | /** |
| 1024 | * The key |
| 1025 | */ |
| 1026 | private K key; |
| 1027 | /** |
| 1028 | * The value |
| 1029 | */ |
| 1030 | private V value; |
| 1031 | |
| 1032 | protected HashEntry(HashEntry<K, V> next, int hashCode, K key, V value) { |
| 1033 | super(); |
| 1034 | this.next = next; |
| 1035 | this.hashCode = hashCode; |
| 1036 | this.key = key; |
| 1037 | this.value = value; |
| 1038 | } |
| 1039 | |
| 1040 | public K getKey() { |
| 1041 | return key; |
| 1042 | } |
| 1043 | |
| 1044 | public void setKey(K key) { |
| 1045 | this.key = key; |
| 1046 | } |
| 1047 | |
| 1048 | public V getValue() { |
| 1049 | return value; |
| 1050 | } |
| 1051 | |
| 1052 | public V setValue(V value) { |
| 1053 | V old = this.value; |
| 1054 | this.value = value; |
| 1055 | return old; |
| 1056 | } |
| 1057 | |
| 1058 | public boolean equals(Object obj) { |
| 1059 | if (obj == this) { |
| 1060 | return true; |
| 1061 | } |
| 1062 | if (obj instanceof Map.Entry == false) { |
| 1063 | return false; |
| 1064 | } |
| 1065 | Map.Entry other = (Map.Entry) obj; |
| 1066 | return (getKey() == null ? other.getKey() == null : getKey().equals(other.getKey())) && (getValue() == null ? other.getValue() == null : getValue().equals(other.getValue())); |
| 1067 | } |
| 1068 | |
| 1069 | public int hashCode() { |
| 1070 | return (getKey() == null ? 0 : getKey().hashCode()) ^ (getValue() == null ? 0 : getValue().hashCode()); |
| 1071 | } |
| 1072 | |
| 1073 | public String toString() { |
| 1074 | return new StringBuilder().append(getKey()).append('=').append(getValue()).toString(); |
| 1075 | } |
| 1076 | } |
| 1077 | |
| 1078 | /** |
| 1079 | * Base Iterator |
| 1080 | */ |
| 1081 | protected static abstract class HashIterator <K,V> { |
| 1082 | |
| 1083 | /** |
| 1084 | * The parent map |
| 1085 | */ |
| 1086 | protected final AbstractHashedMap parent; |
| 1087 | /** |
| 1088 | * The current index into the array of buckets |
| 1089 | */ |
| 1090 | protected int hashIndex; |
| 1091 | /** |
| 1092 | * The last returned entry |
| 1093 | */ |
| 1094 | protected HashEntry<K, V> last; |
| 1095 | /** |
| 1096 | * The next entry |
| 1097 | */ |
| 1098 | protected HashEntry<K, V> next; |
| 1099 | /** |
| 1100 | * The modification count expected |
| 1101 | */ |
| 1102 | protected int expectedModCount; |
| 1103 | |
| 1104 | protected HashIterator(AbstractHashedMap<K, V> parent) { |
| 1105 | super(); |
| 1106 | this.parent = parent; |
| 1107 | HashEntry<K, V>[] data = parent.data; |
| 1108 | int i = data.length; |
| 1109 | HashEntry<K, V> next = null; |
| 1110 | while (i > 0 && next == null) { |
| 1111 | next = data[--i]; |
| 1112 | } |
| 1113 | this.next = next; |
| 1114 | this.hashIndex = i; |
| 1115 | this.expectedModCount = parent.modCount; |
| 1116 | } |
| 1117 | |
| 1118 | public boolean hasNext() { |
| 1119 | return (next != null); |
| 1120 | } |
| 1121 | |
| 1122 | protected HashEntry<K, V> nextEntry() { |
| 1123 | if (parent.modCount != expectedModCount) { |
| 1124 | throw new ConcurrentModificationException(); |
| 1125 | } |
| 1126 | HashEntry<K, V> newCurrent = next; |
| 1127 | if (newCurrent == null) { |
| 1128 | throw new NoSuchElementException(AbstractHashedMap.NO_NEXT_ENTRY); |
| 1129 | } |
| 1130 | HashEntry<K, V>[] data = parent.data; |
| 1131 | int i = hashIndex; |
| 1132 | HashEntry<K, V> n = newCurrent.next; |
| 1133 | while (n == null && i > 0) { |
| 1134 | n = data[--i]; |
| 1135 | } |
| 1136 | next = n; |
| 1137 | hashIndex = i; |
| 1138 | last = newCurrent; |
| 1139 | return newCurrent; |
| 1140 | } |
| 1141 | |
| 1142 | protected HashEntry<K, V> currentEntry() { |
| 1143 | return last; |
| 1144 | } |
| 1145 | |
| 1146 | public void remove() { |
| 1147 | if (last == null) { |
| 1148 | throw new IllegalStateException(AbstractHashedMap.REMOVE_INVALID); |
| 1149 | } |
| 1150 | if (parent.modCount != expectedModCount) { |
| 1151 | throw new ConcurrentModificationException(); |
| 1152 | } |
| 1153 | parent.remove(last.getKey()); |
| 1154 | last = null; |
| 1155 | expectedModCount = parent.modCount; |
| 1156 | } |
| 1157 | |
| 1158 | public String toString() { |
| 1159 | if (last != null) { |
| 1160 | return "Iterator[" + last.getKey() + "=" + last.getValue() + "]"; |
| 1161 | } else { |
| 1162 | return "Iterator[]"; |
| 1163 | } |
| 1164 | } |
| 1165 | } |
| 1166 | |
| 1167 | //----------------------------------------------------------------------- |
| 1168 | /** |
| 1169 | * Writes the map data to the stream. This method must be overridden if a |
| 1170 | * subclass must be setup before <code>put()</code> is used. |
| 1171 | * <p/> |
| 1172 | * Serialization is not one of the JDK's nicest topics. Normal serialization will |
| 1173 | * initialise the superclass before the subclass. Sometimes however, this isn't |
| 1174 | * what you want, as in this case the <code>put()</code> method on read can be |
| 1175 | * affected by subclass state. |
| 1176 | * <p/> |
| 1177 | * The solution adopted here is to serialize the state data of this class in |
| 1178 | * this protected method. This method must be called by the |
| 1179 | * <code>writeObject()</code> of the first serializable subclass. |
| 1180 | * <p/> |
| 1181 | * Subclasses may override if they have a specific field that must be present |
| 1182 | * on read before this implementation will work. Generally, the read determines |
| 1183 | * what must be serialized here, if anything. |
| 1184 | * |
| 1185 | * @param out the output stream |
| 1186 | */ |
| 1187 | protected void doWriteObject(ObjectOutputStream out) throws IOException { |
| 1188 | out.writeFloat(loadFactor); |
| 1189 | out.writeInt(data.length); |
| 1190 | out.writeInt(size); |
| 1191 | for (MapIterator it = mapIterator(); it.hasNext();) { |
| 1192 | out.writeObject(it.next()); |
| 1193 | out.writeObject(it.getValue()); |
| 1194 | } |
| 1195 | } |
| 1196 | |
| 1197 | /** |
| 1198 | * Reads the map data from the stream. This method must be overridden if a |
| 1199 | * subclass must be setup before <code>put()</code> is used. |
| 1200 | * <p/> |
| 1201 | * Serialization is not one of the JDK's nicest topics. Normal serialization will |
| 1202 | * initialise the superclass before the subclass. Sometimes however, this isn't |
| 1203 | * what you want, as in this case the <code>put()</code> method on read can be |
| 1204 | * affected by subclass state. |
| 1205 | * <p/> |
| 1206 | * The solution adopted here is to deserialize the state data of this class in |
| 1207 | * this protected method. This method must be called by the |
| 1208 | * <code>readObject()</code> of the first serializable subclass. |
| 1209 | * <p/> |
| 1210 | * Subclasses may override if the subclass has a specific field that must be present |
| 1211 | * before <code>put()</code> or <code>calculateThreshold()</code> will work correctly. |
| 1212 | * |
| 1213 | * @param in the input stream |
| 1214 | */ |
| 1215 | protected void doReadObject(ObjectInputStream in) throws IOException, ClassNotFoundException { |
| 1216 | loadFactor = in.readFloat(); |
| 1217 | int capacity = in.readInt(); |
| 1218 | int size = in.readInt(); |
| 1219 | init(); |
| 1220 | data = new HashEntry[capacity]; |
| 1221 | for (int i = 0; i < size; i++) { |
| 1222 | K key = (K) in.readObject(); |
| 1223 | V value = (V) in.readObject(); |
| 1224 | put(key, value); |
| 1225 | } |
| 1226 | threshold = calculateThreshold(data.length, loadFactor); |
| 1227 | } |
| 1228 | |
| 1229 | //----------------------------------------------------------------------- |
| 1230 | /** |
| 1231 | * Clones the map without cloning the keys or values. |
| 1232 | * <p/> |
| 1233 | * To implement <code>clone()</code>, a subclass must implement the |
| 1234 | * <code>Cloneable</code> interface and make this method public. |
| 1235 | * |
| 1236 | * @return a shallow clone |
| 1237 | */ |
| 1238 | protected Object clone() { |
| 1239 | try { |
| 1240 | AbstractHashedMap cloned = (AbstractHashedMap) super.clone(); |
| 1241 | cloned.data = new HashEntry[data.length]; |
| 1242 | cloned.entrySet = null; |
| 1243 | cloned.keySet = null; |
| 1244 | cloned.values = null; |
| 1245 | cloned.modCount = 0; |
| 1246 | cloned.size = 0; |
| 1247 | cloned.init(); |
| 1248 | cloned.putAll(this); |
| 1249 | return cloned; |
| 1250 | |
| 1251 | } catch (CloneNotSupportedException ex) { |
| 1252 | return null; // should never happen |
| 1253 | } |
| 1254 | } |
| 1255 | |
| 1256 | /** |
| 1257 | * Compares this map with another. |
| 1258 | * |
| 1259 | * @param obj the object to compare to |
| 1260 | * @return true if equal |
| 1261 | */ |
| 1262 | public boolean equals(Object obj) { |
| 1263 | if (obj == this) { |
| 1264 | return true; |
| 1265 | } |
| 1266 | if (obj instanceof Map == false) { |
| 1267 | return false; |
| 1268 | } |
| 1269 | Map map = (Map) obj; |
| 1270 | if (map.size() != size()) { |
| 1271 | return false; |
| 1272 | } |
| 1273 | MapIterator it = mapIterator(); |
| 1274 | try { |
| 1275 | while (it.hasNext()) { |
| 1276 | Object key = it.next(); |
| 1277 | Object value = it.getValue(); |
| 1278 | if (value == null) { |
| 1279 | if (map.get(key) != null || map.containsKey(key) == false) { |
| 1280 | return false; |
| 1281 | } |
| 1282 | } else { |
| 1283 | if (value.equals(map.get(key)) == false) { |
| 1284 | return false; |
| 1285 | } |
| 1286 | } |
| 1287 | } |
| 1288 | } catch (ClassCastException ignored) { |
| 1289 | return false; |
| 1290 | } catch (NullPointerException ignored) { |
| 1291 | return false; |
| 1292 | } |
| 1293 | return true; |
| 1294 | } |
| 1295 | |
| 1296 | /** |
| 1297 | * Gets the standard Map hashCode. |
| 1298 | * |
| 1299 | * @return the hash code defined in the Map interface |
| 1300 | */ |
| 1301 | public int hashCode() { |
| 1302 | int total = 0; |
| 1303 | Iterator it = createEntrySetIterator(); |
| 1304 | while (it.hasNext()) { |
| 1305 | total += it.next().hashCode(); |
| 1306 | } |
| 1307 | return total; |
| 1308 | } |
| 1309 | |
| 1310 | /** |
| 1311 | * Gets the map as a String. |
| 1312 | * |
| 1313 | * @return a string version of the map |
| 1314 | */ |
| 1315 | public String toString() { |
| 1316 | if (size() == 0) { |
| 1317 | return "{}"; |
| 1318 | } |
| 1319 | StringBuilder buf = new StringBuilder(32 * size()); |
| 1320 | buf.append('{'); |
| 1321 | |
| 1322 | MapIterator it = mapIterator(); |
| 1323 | boolean hasNext = it.hasNext(); |
| 1324 | while (hasNext) { |
| 1325 | Object key = it.next(); |
| 1326 | Object value = it.getValue(); |
| 1327 | buf.append(key == this ? "(this Map)" : key).append('=').append(value == this ? "(this Map)" : value); |
| 1328 | |
| 1329 | hasNext = it.hasNext(); |
| 1330 | if (hasNext) { |
| 1331 | buf.append(',').append(' '); |
| 1332 | } |
| 1333 | } |
| 1334 | |
| 1335 | buf.append('}'); |
| 1336 | return buf.toString(); |
| 1337 | } |
| 1338 | } |