TreeMap.java revision 4c89023ef86f29fa9add7db2574f2169fe842577
1/* 2 * Copyright (C) 2014 The Android Open Source Project 3 * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved. 4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 5 * 6 * This code is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License version 2 only, as 8 * published by the Free Software Foundation. Oracle designates this 9 * particular file as subject to the "Classpath" exception as provided 10 * by Oracle in the LICENSE file that accompanied this code. 11 * 12 * This code is distributed in the hope that it will be useful, but WITHOUT 13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 15 * version 2 for more details (a copy is included in the LICENSE file that 16 * accompanied this code). 17 * 18 * You should have received a copy of the GNU General Public License version 19 * 2 along with this work; if not, write to the Free Software Foundation, 20 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 21 * 22 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 23 * or visit www.oracle.com if you need additional information or have any 24 * questions. 25 */ 26 27package java.util; 28 29import java.io.Serializable; 30import java.util.function.BiConsumer; 31import java.util.function.BiFunction; 32import java.util.function.Consumer; 33 34/** 35 * A Red-Black tree based {@link NavigableMap} implementation. 36 * The map is sorted according to the {@linkplain Comparable natural 37 * ordering} of its keys, or by a {@link Comparator} provided at map 38 * creation time, depending on which constructor is used. 39 * 40 * <p>This implementation provides guaranteed log(n) time cost for the 41 * {@code containsKey}, {@code get}, {@code put} and {@code remove} 42 * operations. Algorithms are adaptations of those in Cormen, Leiserson, and 43 * Rivest's <em>Introduction to Algorithms</em>. 44 * 45 * <p>Note that the ordering maintained by a tree map, like any sorted map, and 46 * whether or not an explicit comparator is provided, must be <em>consistent 47 * with {@code equals}</em> if this sorted map is to correctly implement the 48 * {@code Map} interface. (See {@code Comparable} or {@code Comparator} for a 49 * precise definition of <em>consistent with equals</em>.) This is so because 50 * the {@code Map} interface is defined in terms of the {@code equals} 51 * operation, but a sorted map performs all key comparisons using its {@code 52 * compareTo} (or {@code compare}) method, so two keys that are deemed equal by 53 * this method are, from the standpoint of the sorted map, equal. The behavior 54 * of a sorted map <em>is</em> well-defined even if its ordering is 55 * inconsistent with {@code equals}; it just fails to obey the general contract 56 * of the {@code Map} interface. 57 * 58 * <p><strong>Note that this implementation is not synchronized.</strong> 59 * If multiple threads access a map concurrently, and at least one of the 60 * threads modifies the map structurally, it <em>must</em> be synchronized 61 * externally. (A structural modification is any operation that adds or 62 * deletes one or more mappings; merely changing the value associated 63 * with an existing key is not a structural modification.) This is 64 * typically accomplished by synchronizing on some object that naturally 65 * encapsulates the map. 66 * If no such object exists, the map should be "wrapped" using the 67 * {@link Collections#synchronizedSortedMap Collections.synchronizedSortedMap} 68 * method. This is best done at creation time, to prevent accidental 69 * unsynchronized access to the map: <pre> 70 * SortedMap m = Collections.synchronizedSortedMap(new TreeMap(...));</pre> 71 * 72 * <p>The iterators returned by the {@code iterator} method of the collections 73 * returned by all of this class's "collection view methods" are 74 * <em>fail-fast</em>: if the map is structurally modified at any time after 75 * the iterator is created, in any way except through the iterator's own 76 * {@code remove} method, the iterator will throw a {@link 77 * ConcurrentModificationException}. Thus, in the face of concurrent 78 * modification, the iterator fails quickly and cleanly, rather than risking 79 * arbitrary, non-deterministic behavior at an undetermined time in the future. 80 * 81 * <p>Note that the fail-fast behavior of an iterator cannot be guaranteed 82 * as it is, generally speaking, impossible to make any hard guarantees in the 83 * presence of unsynchronized concurrent modification. Fail-fast iterators 84 * throw {@code ConcurrentModificationException} on a best-effort basis. 85 * Therefore, it would be wrong to write a program that depended on this 86 * exception for its correctness: <em>the fail-fast behavior of iterators 87 * should be used only to detect bugs.</em> 88 * 89 * <p>All {@code Map.Entry} pairs returned by methods in this class 90 * and its views represent snapshots of mappings at the time they were 91 * produced. They do <strong>not</strong> support the {@code Entry.setValue} 92 * method. (Note however that it is possible to change mappings in the 93 * associated map using {@code put}.) 94 * 95 * <p>This class is a member of the 96 * <a href="{@docRoot}/../technotes/guides/collections/index.html"> 97 * Java Collections Framework</a>. 98 * 99 * @param <K> the type of keys maintained by this map 100 * @param <V> the type of mapped values 101 * 102 * @author Josh Bloch and Doug Lea 103 * @see Map 104 * @see HashMap 105 * @see Hashtable 106 * @see Comparable 107 * @see Comparator 108 * @see Collection 109 * @since 1.2 110 */ 111 112public class TreeMap<K,V> 113 extends AbstractMap<K,V> 114 implements NavigableMap<K,V>, Cloneable, java.io.Serializable 115{ 116 /** 117 * The comparator used to maintain order in this tree map, or 118 * null if it uses the natural ordering of its keys. 119 * 120 * @serial 121 */ 122 private final Comparator<? super K> comparator; 123 124 private transient TreeMapEntry<K,V> root = null; 125 126 /** 127 * The number of entries in the tree 128 */ 129 private transient int size = 0; 130 131 /** 132 * The number of structural modifications to the tree. 133 */ 134 private transient int modCount = 0; 135 136 /** 137 * Constructs a new, empty tree map, using the natural ordering of its 138 * keys. All keys inserted into the map must implement the {@link 139 * Comparable} interface. Furthermore, all such keys must be 140 * <em>mutually comparable</em>: {@code k1.compareTo(k2)} must not throw 141 * a {@code ClassCastException} for any keys {@code k1} and 142 * {@code k2} in the map. If the user attempts to put a key into the 143 * map that violates this constraint (for example, the user attempts to 144 * put a string key into a map whose keys are integers), the 145 * {@code put(Object key, Object value)} call will throw a 146 * {@code ClassCastException}. 147 */ 148 public TreeMap() { 149 comparator = null; 150 } 151 152 /** 153 * Constructs a new, empty tree map, ordered according to the given 154 * comparator. All keys inserted into the map must be <em>mutually 155 * comparable</em> by the given comparator: {@code comparator.compare(k1, 156 * k2)} must not throw a {@code ClassCastException} for any keys 157 * {@code k1} and {@code k2} in the map. If the user attempts to put 158 * a key into the map that violates this constraint, the {@code put(Object 159 * key, Object value)} call will throw a 160 * {@code ClassCastException}. 161 * 162 * @param comparator the comparator that will be used to order this map. 163 * If {@code null}, the {@linkplain Comparable natural 164 * ordering} of the keys will be used. 165 */ 166 public TreeMap(Comparator<? super K> comparator) { 167 this.comparator = comparator; 168 } 169 170 /** 171 * Constructs a new tree map containing the same mappings as the given 172 * map, ordered according to the <em>natural ordering</em> of its keys. 173 * All keys inserted into the new map must implement the {@link 174 * Comparable} interface. Furthermore, all such keys must be 175 * <em>mutually comparable</em>: {@code k1.compareTo(k2)} must not throw 176 * a {@code ClassCastException} for any keys {@code k1} and 177 * {@code k2} in the map. This method runs in n*log(n) time. 178 * 179 * @param m the map whose mappings are to be placed in this map 180 * @throws ClassCastException if the keys in m are not {@link Comparable}, 181 * or are not mutually comparable 182 * @throws NullPointerException if the specified map is null 183 */ 184 public TreeMap(Map<? extends K, ? extends V> m) { 185 comparator = null; 186 putAll(m); 187 } 188 189 /** 190 * Constructs a new tree map containing the same mappings and 191 * using the same ordering as the specified sorted map. This 192 * method runs in linear time. 193 * 194 * @param m the sorted map whose mappings are to be placed in this map, 195 * and whose comparator is to be used to sort this map 196 * @throws NullPointerException if the specified map is null 197 */ 198 public TreeMap(SortedMap<K, ? extends V> m) { 199 comparator = m.comparator(); 200 try { 201 buildFromSorted(m.size(), m.entrySet().iterator(), null, null); 202 } catch (java.io.IOException cannotHappen) { 203 } catch (ClassNotFoundException cannotHappen) { 204 } 205 } 206 207 208 // Query Operations 209 210 /** 211 * Returns the number of key-value mappings in this map. 212 * 213 * @return the number of key-value mappings in this map 214 */ 215 public int size() { 216 return size; 217 } 218 219 /** 220 * Returns {@code true} if this map contains a mapping for the specified 221 * key. 222 * 223 * @param key key whose presence in this map is to be tested 224 * @return {@code true} if this map contains a mapping for the 225 * specified key 226 * @throws ClassCastException if the specified key cannot be compared 227 * with the keys currently in the map 228 * @throws NullPointerException if the specified key is null 229 * and this map uses natural ordering, or its comparator 230 * does not permit null keys 231 */ 232 public boolean containsKey(Object key) { 233 return getEntry(key) != null; 234 } 235 236 /** 237 * Returns {@code true} if this map maps one or more keys to the 238 * specified value. More formally, returns {@code true} if and only if 239 * this map contains at least one mapping to a value {@code v} such 240 * that {@code (value==null ? v==null : value.equals(v))}. This 241 * operation will probably require time linear in the map size for 242 * most implementations. 243 * 244 * @param value value whose presence in this map is to be tested 245 * @return {@code true} if a mapping to {@code value} exists; 246 * {@code false} otherwise 247 * @since 1.2 248 */ 249 public boolean containsValue(Object value) { 250 for (TreeMapEntry<K,V> e = getFirstEntry(); e != null; e = successor(e)) 251 if (valEquals(value, e.value)) 252 return true; 253 return false; 254 } 255 256 /** 257 * Returns the value to which the specified key is mapped, 258 * or {@code null} if this map contains no mapping for the key. 259 * 260 * <p>More formally, if this map contains a mapping from a key 261 * {@code k} to a value {@code v} such that {@code key} compares 262 * equal to {@code k} according to the map's ordering, then this 263 * method returns {@code v}; otherwise it returns {@code null}. 264 * (There can be at most one such mapping.) 265 * 266 * <p>A return value of {@code null} does not <em>necessarily</em> 267 * indicate that the map contains no mapping for the key; it's also 268 * possible that the map explicitly maps the key to {@code null}. 269 * The {@link #containsKey containsKey} operation may be used to 270 * distinguish these two cases. 271 * 272 * @throws ClassCastException if the specified key cannot be compared 273 * with the keys currently in the map 274 * @throws NullPointerException if the specified key is null 275 * and this map uses natural ordering, or its comparator 276 * does not permit null keys 277 */ 278 public V get(Object key) { 279 TreeMapEntry<K,V> p = getEntry(key); 280 return (p==null ? null : p.value); 281 } 282 283 public Comparator<? super K> comparator() { 284 return comparator; 285 } 286 287 /** 288 * @throws NoSuchElementException {@inheritDoc} 289 */ 290 public K firstKey() { 291 return key(getFirstEntry()); 292 } 293 294 /** 295 * @throws NoSuchElementException {@inheritDoc} 296 */ 297 public K lastKey() { 298 return key(getLastEntry()); 299 } 300 301 /** 302 * Copies all of the mappings from the specified map to this map. 303 * These mappings replace any mappings that this map had for any 304 * of the keys currently in the specified map. 305 * 306 * @param map mappings to be stored in this map 307 * @throws ClassCastException if the class of a key or value in 308 * the specified map prevents it from being stored in this map 309 * @throws NullPointerException if the specified map is null or 310 * the specified map contains a null key and this map does not 311 * permit null keys 312 */ 313 public void putAll(Map<? extends K, ? extends V> map) { 314 int mapSize = map.size(); 315 if (size==0 && mapSize!=0 && map instanceof SortedMap) { 316 Comparator<?> c = ((SortedMap<?,?>)map).comparator(); 317 if (c == comparator || (c != null && c.equals(comparator))) { 318 ++modCount; 319 try { 320 buildFromSorted(mapSize, map.entrySet().iterator(), 321 null, null); 322 } catch (java.io.IOException cannotHappen) { 323 } catch (ClassNotFoundException cannotHappen) { 324 } 325 return; 326 } 327 } 328 super.putAll(map); 329 } 330 331 /** 332 * Returns this map's entry for the given key, or {@code null} if the map 333 * does not contain an entry for the key. 334 * 335 * @return this map's entry for the given key, or {@code null} if the map 336 * does not contain an entry for the key 337 * @throws ClassCastException if the specified key cannot be compared 338 * with the keys currently in the map 339 * @throws NullPointerException if the specified key is null 340 * and this map uses natural ordering, or its comparator 341 * does not permit null keys 342 */ 343 final TreeMapEntry<K,V> getEntry(Object key) { 344 // Offload comparator-based version for sake of performance 345 if (comparator != null) 346 return getEntryUsingComparator(key); 347 if (key == null) 348 throw new NullPointerException(); 349 @SuppressWarnings("unchecked") 350 Comparable<? super K> k = (Comparable<? super K>) key; 351 TreeMapEntry<K,V> p = root; 352 while (p != null) { 353 int cmp = k.compareTo(p.key); 354 if (cmp < 0) 355 p = p.left; 356 else if (cmp > 0) 357 p = p.right; 358 else 359 return p; 360 } 361 return null; 362 } 363 364 /** 365 * Version of getEntry using comparator. Split off from getEntry 366 * for performance. (This is not worth doing for most methods, 367 * that are less dependent on comparator performance, but is 368 * worthwhile here.) 369 */ 370 final TreeMapEntry<K,V> getEntryUsingComparator(Object key) { 371 @SuppressWarnings("unchecked") 372 K k = (K) key; 373 Comparator<? super K> cpr = comparator; 374 if (cpr != null) { 375 TreeMapEntry<K,V> p = root; 376 while (p != null) { 377 int cmp = cpr.compare(k, p.key); 378 if (cmp < 0) 379 p = p.left; 380 else if (cmp > 0) 381 p = p.right; 382 else 383 return p; 384 } 385 } 386 return null; 387 } 388 389 /** 390 * Gets the entry corresponding to the specified key; if no such entry 391 * exists, returns the entry for the least key greater than the specified 392 * key; if no such entry exists (i.e., the greatest key in the Tree is less 393 * than the specified key), returns {@code null}. 394 */ 395 final TreeMapEntry<K,V> getCeilingEntry(K key) { 396 TreeMapEntry<K,V> p = root; 397 while (p != null) { 398 int cmp = compare(key, p.key); 399 if (cmp < 0) { 400 if (p.left != null) 401 p = p.left; 402 else 403 return p; 404 } else if (cmp > 0) { 405 if (p.right != null) { 406 p = p.right; 407 } else { 408 TreeMapEntry<K,V> parent = p.parent; 409 TreeMapEntry<K,V> ch = p; 410 while (parent != null && ch == parent.right) { 411 ch = parent; 412 parent = parent.parent; 413 } 414 return parent; 415 } 416 } else 417 return p; 418 } 419 return null; 420 } 421 422 /** 423 * Gets the entry corresponding to the specified key; if no such entry 424 * exists, returns the entry for the greatest key less than the specified 425 * key; if no such entry exists, returns {@code null}. 426 */ 427 final TreeMapEntry<K,V> getFloorEntry(K key) { 428 TreeMapEntry<K,V> p = root; 429 while (p != null) { 430 int cmp = compare(key, p.key); 431 if (cmp > 0) { 432 if (p.right != null) 433 p = p.right; 434 else 435 return p; 436 } else if (cmp < 0) { 437 if (p.left != null) { 438 p = p.left; 439 } else { 440 TreeMapEntry<K,V> parent = p.parent; 441 TreeMapEntry<K,V> ch = p; 442 while (parent != null && ch == parent.left) { 443 ch = parent; 444 parent = parent.parent; 445 } 446 return parent; 447 } 448 } else 449 return p; 450 451 } 452 return null; 453 } 454 455 /** 456 * Gets the entry for the least key greater than the specified 457 * key; if no such entry exists, returns the entry for the least 458 * key greater than the specified key; if no such entry exists 459 * returns {@code null}. 460 */ 461 final TreeMapEntry<K,V> getHigherEntry(K key) { 462 TreeMapEntry<K,V> p = root; 463 while (p != null) { 464 int cmp = compare(key, p.key); 465 if (cmp < 0) { 466 if (p.left != null) 467 p = p.left; 468 else 469 return p; 470 } else { 471 if (p.right != null) { 472 p = p.right; 473 } else { 474 TreeMapEntry<K,V> parent = p.parent; 475 TreeMapEntry<K,V> ch = p; 476 while (parent != null && ch == parent.right) { 477 ch = parent; 478 parent = parent.parent; 479 } 480 return parent; 481 } 482 } 483 } 484 return null; 485 } 486 487 /** 488 * Returns the entry for the greatest key less than the specified key; if 489 * no such entry exists (i.e., the least key in the Tree is greater than 490 * the specified key), returns {@code null}. 491 */ 492 final TreeMapEntry<K,V> getLowerEntry(K key) { 493 TreeMapEntry<K,V> p = root; 494 while (p != null) { 495 int cmp = compare(key, p.key); 496 if (cmp > 0) { 497 if (p.right != null) 498 p = p.right; 499 else 500 return p; 501 } else { 502 if (p.left != null) { 503 p = p.left; 504 } else { 505 TreeMapEntry<K,V> parent = p.parent; 506 TreeMapEntry<K,V> ch = p; 507 while (parent != null && ch == parent.left) { 508 ch = parent; 509 parent = parent.parent; 510 } 511 return parent; 512 } 513 } 514 } 515 return null; 516 } 517 518 /** 519 * Associates the specified value with the specified key in this map. 520 * If the map previously contained a mapping for the key, the old 521 * value is replaced. 522 * 523 * @param key key with which the specified value is to be associated 524 * @param value value to be associated with the specified key 525 * 526 * @return the previous value associated with {@code key}, or 527 * {@code null} if there was no mapping for {@code key}. 528 * (A {@code null} return can also indicate that the map 529 * previously associated {@code null} with {@code key}.) 530 * @throws ClassCastException if the specified key cannot be compared 531 * with the keys currently in the map 532 * @throws NullPointerException if the specified key is null 533 * and this map uses natural ordering, or its comparator 534 * does not permit null keys 535 */ 536 public V put(K key, V value) { 537 TreeMapEntry<K,V> t = root; 538 if (t == null) { 539 // We could just call compare(key, key) for its side effect of checking the type and 540 // nullness of the input key. However, several applications seem to have written comparators 541 // that only expect to be called on elements that aren't equal to each other (after 542 // making assumptions about the domain of the map). Clearly, such comparators are bogus 543 // because get() would never work, but TreeSets are frequently used for sorting a set 544 // of distinct elements. 545 // 546 // As a temporary work around, we perform the null & instanceof checks by hand so that 547 // we can guarantee that elements are never compared against themselves. 548 // 549 // compare(key, key); 550 // 551 // **** THIS CHANGE WILL BE REVERTED IN A FUTURE ANDROID RELEASE **** 552 if (comparator != null) { 553 if (key == null) { 554 comparator.compare(key, key); 555 } 556 } else { 557 if (key == null) { 558 throw new NullPointerException("key == null"); 559 } else if (!(key instanceof Comparable)) { 560 throw new ClassCastException( 561 "Cannot cast" + key.getClass().getName() + " to Comparable."); 562 } 563 } 564 565 root = new TreeMapEntry<>(key, value, null); 566 size = 1; 567 modCount++; 568 return null; 569 } 570 int cmp; 571 TreeMapEntry<K,V> parent; 572 // split comparator and comparable paths 573 Comparator<? super K> cpr = comparator; 574 if (cpr != null) { 575 do { 576 parent = t; 577 cmp = cpr.compare(key, t.key); 578 if (cmp < 0) 579 t = t.left; 580 else if (cmp > 0) 581 t = t.right; 582 else 583 return t.setValue(value); 584 } while (t != null); 585 } 586 else { 587 if (key == null) 588 throw new NullPointerException(); 589 @SuppressWarnings("unchecked") 590 Comparable<? super K> k = (Comparable<? super K>) key; 591 do { 592 parent = t; 593 cmp = k.compareTo(t.key); 594 if (cmp < 0) 595 t = t.left; 596 else if (cmp > 0) 597 t = t.right; 598 else 599 return t.setValue(value); 600 } while (t != null); 601 } 602 TreeMapEntry<K,V> e = new TreeMapEntry<>(key, value, parent); 603 if (cmp < 0) 604 parent.left = e; 605 else 606 parent.right = e; 607 fixAfterInsertion(e); 608 size++; 609 modCount++; 610 return null; 611 } 612 613 /** 614 * Removes the mapping for this key from this TreeMap if present. 615 * 616 * @param key key for which mapping should be removed 617 * @return the previous value associated with {@code key}, or 618 * {@code null} if there was no mapping for {@code key}. 619 * (A {@code null} return can also indicate that the map 620 * previously associated {@code null} with {@code key}.) 621 * @throws ClassCastException if the specified key cannot be compared 622 * with the keys currently in the map 623 * @throws NullPointerException if the specified key is null 624 * and this map uses natural ordering, or its comparator 625 * does not permit null keys 626 */ 627 public V remove(Object key) { 628 TreeMapEntry<K,V> p = getEntry(key); 629 if (p == null) 630 return null; 631 632 V oldValue = p.value; 633 deleteEntry(p); 634 return oldValue; 635 } 636 637 /** 638 * Removes all of the mappings from this map. 639 * The map will be empty after this call returns. 640 */ 641 public void clear() { 642 modCount++; 643 size = 0; 644 root = null; 645 } 646 647 /** 648 * Returns a shallow copy of this {@code TreeMap} instance. (The keys and 649 * values themselves are not cloned.) 650 * 651 * @return a shallow copy of this map 652 */ 653 public Object clone() { 654 TreeMap<?,?> clone; 655 try { 656 clone = (TreeMap<?,?>) super.clone(); 657 } catch (CloneNotSupportedException e) { 658 throw new InternalError(e); 659 } 660 661 // Put clone into "virgin" state (except for comparator) 662 clone.root = null; 663 clone.size = 0; 664 clone.modCount = 0; 665 clone.entrySet = null; 666 clone.navigableKeySet = null; 667 clone.descendingMap = null; 668 669 // Initialize clone with our mappings 670 try { 671 clone.buildFromSorted(size, entrySet().iterator(), null, null); 672 } catch (java.io.IOException cannotHappen) { 673 } catch (ClassNotFoundException cannotHappen) { 674 } 675 676 return clone; 677 } 678 679 // NavigableMap API methods 680 681 /** 682 * @since 1.6 683 */ 684 public Map.Entry<K,V> firstEntry() { 685 return exportEntry(getFirstEntry()); 686 } 687 688 /** 689 * @since 1.6 690 */ 691 public Map.Entry<K,V> lastEntry() { 692 return exportEntry(getLastEntry()); 693 } 694 695 /** 696 * @since 1.6 697 */ 698 public Map.Entry<K,V> pollFirstEntry() { 699 TreeMapEntry<K,V> p = getFirstEntry(); 700 Map.Entry<K,V> result = exportEntry(p); 701 if (p != null) 702 deleteEntry(p); 703 return result; 704 } 705 706 /** 707 * @since 1.6 708 */ 709 public Map.Entry<K,V> pollLastEntry() { 710 TreeMapEntry<K,V> p = getLastEntry(); 711 Map.Entry<K,V> result = exportEntry(p); 712 if (p != null) 713 deleteEntry(p); 714 return result; 715 } 716 717 /** 718 * @throws ClassCastException {@inheritDoc} 719 * @throws NullPointerException if the specified key is null 720 * and this map uses natural ordering, or its comparator 721 * does not permit null keys 722 * @since 1.6 723 */ 724 public Map.Entry<K,V> lowerEntry(K key) { 725 return exportEntry(getLowerEntry(key)); 726 } 727 728 /** 729 * @throws ClassCastException {@inheritDoc} 730 * @throws NullPointerException if the specified key is null 731 * and this map uses natural ordering, or its comparator 732 * does not permit null keys 733 * @since 1.6 734 */ 735 public K lowerKey(K key) { 736 return keyOrNull(getLowerEntry(key)); 737 } 738 739 /** 740 * @throws ClassCastException {@inheritDoc} 741 * @throws NullPointerException if the specified key is null 742 * and this map uses natural ordering, or its comparator 743 * does not permit null keys 744 * @since 1.6 745 */ 746 public Map.Entry<K,V> floorEntry(K key) { 747 return exportEntry(getFloorEntry(key)); 748 } 749 750 /** 751 * @throws ClassCastException {@inheritDoc} 752 * @throws NullPointerException if the specified key is null 753 * and this map uses natural ordering, or its comparator 754 * does not permit null keys 755 * @since 1.6 756 */ 757 public K floorKey(K key) { 758 return keyOrNull(getFloorEntry(key)); 759 } 760 761 /** 762 * @throws ClassCastException {@inheritDoc} 763 * @throws NullPointerException if the specified key is null 764 * and this map uses natural ordering, or its comparator 765 * does not permit null keys 766 * @since 1.6 767 */ 768 public Map.Entry<K,V> ceilingEntry(K key) { 769 return exportEntry(getCeilingEntry(key)); 770 } 771 772 /** 773 * @throws ClassCastException {@inheritDoc} 774 * @throws NullPointerException if the specified key is null 775 * and this map uses natural ordering, or its comparator 776 * does not permit null keys 777 * @since 1.6 778 */ 779 public K ceilingKey(K key) { 780 return keyOrNull(getCeilingEntry(key)); 781 } 782 783 /** 784 * @throws ClassCastException {@inheritDoc} 785 * @throws NullPointerException if the specified key is null 786 * and this map uses natural ordering, or its comparator 787 * does not permit null keys 788 * @since 1.6 789 */ 790 public Map.Entry<K,V> higherEntry(K key) { 791 return exportEntry(getHigherEntry(key)); 792 } 793 794 /** 795 * @throws ClassCastException {@inheritDoc} 796 * @throws NullPointerException if the specified key is null 797 * and this map uses natural ordering, or its comparator 798 * does not permit null keys 799 * @since 1.6 800 */ 801 public K higherKey(K key) { 802 return keyOrNull(getHigherEntry(key)); 803 } 804 805 // Views 806 807 /** 808 * Fields initialized to contain an instance of the entry set view 809 * the first time this view is requested. Views are stateless, so 810 * there's no reason to create more than one. 811 */ 812 private transient EntrySet entrySet = null; 813 private transient KeySet<K> navigableKeySet = null; 814 private transient NavigableMap<K,V> descendingMap = null; 815 816 /** 817 * Returns a {@link Set} view of the keys contained in this map. 818 * 819 * <p>The set's iterator returns the keys in ascending order. 820 * The set's spliterator is 821 * <em><a href="Spliterator.html#binding">late-binding</a></em>, 822 * <em>fail-fast</em>, and additionally reports {@link Spliterator#SORTED} 823 * and {@link Spliterator#ORDERED} with an encounter order that is ascending 824 * key order. The spliterator's comparator (see 825 * {@link java.util.Spliterator#getComparator()}) is {@code null} if 826 * the tree map's comparator (see {@link #comparator()}) is {@code null}. 827 * Otherwise, the spliterator's comparator is the same as or imposes the 828 * same total ordering as the tree map's comparator. 829 * 830 * <p>The set is backed by the map, so changes to the map are 831 * reflected in the set, and vice-versa. If the map is modified 832 * while an iteration over the set is in progress (except through 833 * the iterator's own {@code remove} operation), the results of 834 * the iteration are undefined. The set supports element removal, 835 * which removes the corresponding mapping from the map, via the 836 * {@code Iterator.remove}, {@code Set.remove}, 837 * {@code removeAll}, {@code retainAll}, and {@code clear} 838 * operations. It does not support the {@code add} or {@code addAll} 839 * operations. 840 */ 841 public Set<K> keySet() { 842 return navigableKeySet(); 843 } 844 845 /** 846 * @since 1.6 847 */ 848 public NavigableSet<K> navigableKeySet() { 849 KeySet<K> nks = navigableKeySet; 850 return (nks != null) ? nks : (navigableKeySet = new KeySet<>(this)); 851 } 852 853 /** 854 * @since 1.6 855 */ 856 public NavigableSet<K> descendingKeySet() { 857 return descendingMap().navigableKeySet(); 858 } 859 860 /** 861 * Returns a {@link Collection} view of the values contained in this map. 862 * 863 * <p>The collection's iterator returns the values in ascending order 864 * of the corresponding keys. The collection's spliterator is 865 * <em><a href="Spliterator.html#binding">late-binding</a></em>, 866 * <em>fail-fast</em>, and additionally reports {@link Spliterator#ORDERED} 867 * with an encounter order that is ascending order of the corresponding 868 * keys. 869 * 870 * <p>The collection is backed by the map, so changes to the map are 871 * reflected in the collection, and vice-versa. If the map is 872 * modified while an iteration over the collection is in progress 873 * (except through the iterator's own {@code remove} operation), 874 * the results of the iteration are undefined. The collection 875 * supports element removal, which removes the corresponding 876 * mapping from the map, via the {@code Iterator.remove}, 877 * {@code Collection.remove}, {@code removeAll}, 878 * {@code retainAll} and {@code clear} operations. It does not 879 * support the {@code add} or {@code addAll} operations. 880 */ 881 public Collection<V> values() { 882 Collection<V> vs = values; 883 return (vs != null) ? vs : (values = new Values()); 884 } 885 886 /** 887 * Returns a {@link Set} view of the mappings contained in this map. 888 * 889 * <p>The set's iterator returns the entries in ascending key order. The 890 * sets's spliterator is 891 * <em><a href="Spliterator.html#binding">late-binding</a></em>, 892 * <em>fail-fast</em>, and additionally reports {@link Spliterator#SORTED} and 893 * {@link Spliterator#ORDERED} with an encounter order that is ascending key 894 * order. 895 * 896 * <p>The set is backed by the map, so changes to the map are 897 * reflected in the set, and vice-versa. If the map is modified 898 * while an iteration over the set is in progress (except through 899 * the iterator's own {@code remove} operation, or through the 900 * {@code setValue} operation on a map entry returned by the 901 * iterator) the results of the iteration are undefined. The set 902 * supports element removal, which removes the corresponding 903 * mapping from the map, via the {@code Iterator.remove}, 904 * {@code Set.remove}, {@code removeAll}, {@code retainAll} and 905 * {@code clear} operations. It does not support the 906 * {@code add} or {@code addAll} operations. 907 */ 908 public Set<Map.Entry<K,V>> entrySet() { 909 EntrySet es = entrySet; 910 return (es != null) ? es : (entrySet = new EntrySet()); 911 } 912 913 /** 914 * @since 1.6 915 */ 916 public NavigableMap<K, V> descendingMap() { 917 NavigableMap<K, V> km = descendingMap; 918 return (km != null) ? km : 919 (descendingMap = new DescendingSubMap<>(this, 920 true, null, true, 921 true, null, true)); 922 } 923 924 /** 925 * @throws ClassCastException {@inheritDoc} 926 * @throws NullPointerException if {@code fromKey} or {@code toKey} is 927 * null and this map uses natural ordering, or its comparator 928 * does not permit null keys 929 * @throws IllegalArgumentException {@inheritDoc} 930 * @since 1.6 931 */ 932 public NavigableMap<K,V> subMap(K fromKey, boolean fromInclusive, 933 K toKey, boolean toInclusive) { 934 return new AscendingSubMap<>(this, 935 false, fromKey, fromInclusive, 936 false, toKey, toInclusive); 937 } 938 939 /** 940 * @throws ClassCastException {@inheritDoc} 941 * @throws NullPointerException if {@code toKey} is null 942 * and this map uses natural ordering, or its comparator 943 * does not permit null keys 944 * @throws IllegalArgumentException {@inheritDoc} 945 * @since 1.6 946 */ 947 public NavigableMap<K,V> headMap(K toKey, boolean inclusive) { 948 return new AscendingSubMap<>(this, 949 true, null, true, 950 false, toKey, inclusive); 951 } 952 953 /** 954 * @throws ClassCastException {@inheritDoc} 955 * @throws NullPointerException if {@code fromKey} is null 956 * and this map uses natural ordering, or its comparator 957 * does not permit null keys 958 * @throws IllegalArgumentException {@inheritDoc} 959 * @since 1.6 960 */ 961 public NavigableMap<K,V> tailMap(K fromKey, boolean inclusive) { 962 return new AscendingSubMap<>(this, 963 false, fromKey, inclusive, 964 true, null, true); 965 } 966 967 /** 968 * @throws ClassCastException {@inheritDoc} 969 * @throws NullPointerException if {@code fromKey} or {@code toKey} is 970 * null and this map uses natural ordering, or its comparator 971 * does not permit null keys 972 * @throws IllegalArgumentException {@inheritDoc} 973 */ 974 public SortedMap<K,V> subMap(K fromKey, K toKey) { 975 return subMap(fromKey, true, toKey, false); 976 } 977 978 /** 979 * @throws ClassCastException {@inheritDoc} 980 * @throws NullPointerException if {@code toKey} is null 981 * and this map uses natural ordering, or its comparator 982 * does not permit null keys 983 * @throws IllegalArgumentException {@inheritDoc} 984 */ 985 public SortedMap<K,V> headMap(K toKey) { 986 return headMap(toKey, false); 987 } 988 989 /** 990 * @throws ClassCastException {@inheritDoc} 991 * @throws NullPointerException if {@code fromKey} is null 992 * and this map uses natural ordering, or its comparator 993 * does not permit null keys 994 * @throws IllegalArgumentException {@inheritDoc} 995 */ 996 public SortedMap<K,V> tailMap(K fromKey) { 997 return tailMap(fromKey, true); 998 } 999 1000 @Override 1001 public void forEach(BiConsumer<? super K, ? super V> action) { 1002 Objects.requireNonNull(action); 1003 int expectedModCount = modCount; 1004 for (TreeMapEntry<K, V> e = getFirstEntry(); e != null; e = successor(e)) { 1005 action.accept(e.key, e.value); 1006 1007 if (expectedModCount != modCount) { 1008 throw new ConcurrentModificationException(); 1009 } 1010 } 1011 } 1012 1013 // View class support 1014 1015 class Values extends AbstractCollection<V> { 1016 public Iterator<V> iterator() { 1017 return new ValueIterator(getFirstEntry()); 1018 } 1019 1020 public int size() { 1021 return TreeMap.this.size(); 1022 } 1023 1024 public boolean contains(Object o) { 1025 return TreeMap.this.containsValue(o); 1026 } 1027 1028 public boolean remove(Object o) { 1029 for (TreeMapEntry<K,V> e = getFirstEntry(); e != null; e = successor(e)) { 1030 if (valEquals(e.getValue(), o)) { 1031 deleteEntry(e); 1032 return true; 1033 } 1034 } 1035 return false; 1036 } 1037 1038 public void clear() { 1039 TreeMap.this.clear(); 1040 } 1041 1042 public Spliterator<V> spliterator() { 1043 return new ValueSpliterator<K,V>(TreeMap.this, null, null, 0, -1, 0); 1044 } 1045 } 1046 1047 class EntrySet extends AbstractSet<Map.Entry<K,V>> { 1048 public Iterator<Map.Entry<K,V>> iterator() { 1049 return new EntryIterator(getFirstEntry()); 1050 } 1051 1052 public boolean contains(Object o) { 1053 if (!(o instanceof Map.Entry)) 1054 return false; 1055 Map.Entry<K,V> entry = (Map.Entry<K,V>) o; 1056 V value = entry.getValue(); 1057 TreeMapEntry<K,V> p = getEntry(entry.getKey()); 1058 return p != null && valEquals(p.getValue(), value); 1059 } 1060 1061 public boolean remove(Object o) { 1062 if (!(o instanceof Map.Entry)) 1063 return false; 1064 Map.Entry<K,V> entry = (Map.Entry<K,V>) o; 1065 V value = entry.getValue(); 1066 TreeMapEntry<K,V> p = getEntry(entry.getKey()); 1067 if (p != null && valEquals(p.getValue(), value)) { 1068 deleteEntry(p); 1069 return true; 1070 } 1071 return false; 1072 } 1073 1074 public int size() { 1075 return TreeMap.this.size(); 1076 } 1077 1078 public void clear() { 1079 TreeMap.this.clear(); 1080 } 1081 1082 public Spliterator<Map.Entry<K,V>> spliterator() { 1083 return new EntrySpliterator<K,V>(TreeMap.this, null, null, 0, -1, 0); 1084 } 1085 } 1086 1087 /* 1088 * Unlike Values and EntrySet, the KeySet class is static, 1089 * delegating to a NavigableMap to allow use by SubMaps, which 1090 * outweighs the ugliness of needing type-tests for the following 1091 * Iterator methods that are defined appropriately in main versus 1092 * submap classes. 1093 */ 1094 1095 Iterator<K> keyIterator() { 1096 return new KeyIterator(getFirstEntry()); 1097 } 1098 1099 Iterator<K> descendingKeyIterator() { 1100 return new DescendingKeyIterator(getLastEntry()); 1101 } 1102 1103 static final class KeySet<E> extends AbstractSet<E> implements NavigableSet<E> { 1104 private final NavigableMap<E, ?> m; 1105 KeySet(NavigableMap<E,?> map) { m = map; } 1106 1107 public Iterator<E> iterator() { 1108 if (m instanceof TreeMap) 1109 return ((TreeMap<E,?>)m).keyIterator(); 1110 else 1111 return ((TreeMap.NavigableSubMap<E,?>)m).keyIterator(); 1112 } 1113 1114 public Iterator<E> descendingIterator() { 1115 if (m instanceof TreeMap) 1116 return ((TreeMap<E,?>)m).descendingKeyIterator(); 1117 else 1118 return ((TreeMap.NavigableSubMap<E,?>)m).descendingKeyIterator(); 1119 } 1120 1121 public int size() { return m.size(); } 1122 public boolean isEmpty() { return m.isEmpty(); } 1123 public boolean contains(Object o) { return m.containsKey(o); } 1124 public void clear() { m.clear(); } 1125 public E lower(E e) { return m.lowerKey(e); } 1126 public E floor(E e) { return m.floorKey(e); } 1127 public E ceiling(E e) { return m.ceilingKey(e); } 1128 public E higher(E e) { return m.higherKey(e); } 1129 public E first() { return m.firstKey(); } 1130 public E last() { return m.lastKey(); } 1131 public Comparator<? super E> comparator() { return m.comparator(); } 1132 public E pollFirst() { 1133 Map.Entry<E,?> e = m.pollFirstEntry(); 1134 return (e == null) ? null : e.getKey(); 1135 } 1136 public E pollLast() { 1137 Map.Entry<E,?> e = m.pollLastEntry(); 1138 return (e == null) ? null : e.getKey(); 1139 } 1140 public boolean remove(Object o) { 1141 int oldSize = size(); 1142 m.remove(o); 1143 return size() != oldSize; 1144 } 1145 public NavigableSet<E> subSet(E fromElement, boolean fromInclusive, 1146 E toElement, boolean toInclusive) { 1147 return new KeySet<>(m.subMap(fromElement, fromInclusive, 1148 toElement, toInclusive)); 1149 } 1150 public NavigableSet<E> headSet(E toElement, boolean inclusive) { 1151 return new KeySet<>(m.headMap(toElement, inclusive)); 1152 } 1153 public NavigableSet<E> tailSet(E fromElement, boolean inclusive) { 1154 return new KeySet<>(m.tailMap(fromElement, inclusive)); 1155 } 1156 public SortedSet<E> subSet(E fromElement, E toElement) { 1157 return subSet(fromElement, true, toElement, false); 1158 } 1159 public SortedSet<E> headSet(E toElement) { 1160 return headSet(toElement, false); 1161 } 1162 public SortedSet<E> tailSet(E fromElement) { 1163 return tailSet(fromElement, true); 1164 } 1165 public NavigableSet<E> descendingSet() { 1166 return new KeySet<>(m.descendingMap()); 1167 } 1168 1169 public Spliterator<E> spliterator() { 1170 return keySpliteratorFor(m); 1171 } 1172 } 1173 1174 /** 1175 * Base class for TreeMap Iterators 1176 */ 1177 abstract class PrivateEntryIterator<T> implements Iterator<T> { 1178 TreeMapEntry<K,V> next; 1179 TreeMapEntry<K,V> lastReturned; 1180 int expectedModCount; 1181 1182 PrivateEntryIterator(TreeMapEntry<K,V> first) { 1183 expectedModCount = modCount; 1184 lastReturned = null; 1185 next = first; 1186 } 1187 1188 public final boolean hasNext() { 1189 return next != null; 1190 } 1191 1192 final TreeMapEntry<K,V> nextEntry() { 1193 TreeMapEntry<K,V> e = next; 1194 if (e == null) 1195 throw new NoSuchElementException(); 1196 if (modCount != expectedModCount) 1197 throw new ConcurrentModificationException(); 1198 next = successor(e); 1199 lastReturned = e; 1200 return e; 1201 } 1202 1203 final TreeMapEntry<K,V> prevEntry() { 1204 TreeMapEntry<K,V> e = next; 1205 if (e == null) 1206 throw new NoSuchElementException(); 1207 if (modCount != expectedModCount) 1208 throw new ConcurrentModificationException(); 1209 next = predecessor(e); 1210 lastReturned = e; 1211 return e; 1212 } 1213 1214 public void remove() { 1215 if (lastReturned == null) 1216 throw new IllegalStateException(); 1217 if (modCount != expectedModCount) 1218 throw new ConcurrentModificationException(); 1219 // deleted entries are replaced by their successors 1220 if (lastReturned.left != null && lastReturned.right != null) 1221 next = lastReturned; 1222 deleteEntry(lastReturned); 1223 expectedModCount = modCount; 1224 lastReturned = null; 1225 } 1226 } 1227 1228 final class EntryIterator extends PrivateEntryIterator<Map.Entry<K,V>> { 1229 EntryIterator(TreeMapEntry<K,V> first) { 1230 super(first); 1231 } 1232 public Map.Entry<K,V> next() { 1233 return nextEntry(); 1234 } 1235 } 1236 1237 final class ValueIterator extends PrivateEntryIterator<V> { 1238 ValueIterator(TreeMapEntry<K,V> first) { 1239 super(first); 1240 } 1241 public V next() { 1242 return nextEntry().value; 1243 } 1244 } 1245 1246 final class KeyIterator extends PrivateEntryIterator<K> { 1247 KeyIterator(TreeMapEntry<K,V> first) { 1248 super(first); 1249 } 1250 public K next() { 1251 return nextEntry().key; 1252 } 1253 } 1254 1255 final class DescendingKeyIterator extends PrivateEntryIterator<K> { 1256 DescendingKeyIterator(TreeMapEntry<K,V> first) { 1257 super(first); 1258 } 1259 public K next() { 1260 return prevEntry().key; 1261 } 1262 public void remove() { 1263 if (lastReturned == null) 1264 throw new IllegalStateException(); 1265 if (modCount != expectedModCount) 1266 throw new ConcurrentModificationException(); 1267 deleteEntry(lastReturned); 1268 lastReturned = null; 1269 expectedModCount = modCount; 1270 } 1271 } 1272 1273 // Little utilities 1274 1275 /** 1276 * Compares two keys using the correct comparison method for this TreeMap. 1277 */ 1278 @SuppressWarnings("unchecked") 1279 final int compare(Object k1, Object k2) { 1280 return comparator==null ? ((Comparable<? super K>)k1).compareTo((K)k2) 1281 : comparator.compare((K)k1, (K)k2); 1282 } 1283 1284 /** 1285 * Test two values for equality. Differs from o1.equals(o2) only in 1286 * that it copes with {@code null} o1 properly. 1287 */ 1288 static final boolean valEquals(Object o1, Object o2) { 1289 return (o1==null ? o2==null : o1.equals(o2)); 1290 } 1291 1292 /** 1293 * Return SimpleImmutableEntry for entry, or null if null 1294 */ 1295 static <K,V> Map.Entry<K,V> exportEntry(TreeMapEntry<K,V> e) { 1296 return (e == null) ? null : 1297 new AbstractMap.SimpleImmutableEntry<>(e); 1298 } 1299 1300 /** 1301 * Return key for entry, or null if null 1302 */ 1303 static <K,V> K keyOrNull(TreeMapEntry<K,V> e) { 1304 return (e == null) ? null : e.key; 1305 } 1306 1307 /** 1308 * Returns the key corresponding to the specified Entry. 1309 * @throws NoSuchElementException if the Entry is null 1310 */ 1311 static <K> K key(TreeMapEntry<K,?> e) { 1312 if (e==null) 1313 throw new NoSuchElementException(); 1314 return e.key; 1315 } 1316 1317 1318 // SubMaps 1319 1320 /** 1321 * Dummy value serving as unmatchable fence key for unbounded 1322 * SubMapIterators 1323 */ 1324 private static final Object UNBOUNDED = new Object(); 1325 1326 /** 1327 * @serial include 1328 */ 1329 abstract static class NavigableSubMap<K,V> extends AbstractMap<K,V> 1330 implements NavigableMap<K,V>, java.io.Serializable { 1331 /** 1332 * The backing map. 1333 */ 1334 final TreeMap<K,V> m; 1335 1336 /** 1337 * Endpoints are represented as triples (fromStart, lo, 1338 * loInclusive) and (toEnd, hi, hiInclusive). If fromStart is 1339 * true, then the low (absolute) bound is the start of the 1340 * backing map, and the other values are ignored. Otherwise, 1341 * if loInclusive is true, lo is the inclusive bound, else lo 1342 * is the exclusive bound. Similarly for the upper bound. 1343 */ 1344 final K lo, hi; 1345 final boolean fromStart, toEnd; 1346 final boolean loInclusive, hiInclusive; 1347 1348 NavigableSubMap(TreeMap<K,V> m, 1349 boolean fromStart, K lo, boolean loInclusive, 1350 boolean toEnd, K hi, boolean hiInclusive) { 1351 if (!fromStart && !toEnd) { 1352 if (m.compare(lo, hi) > 0) 1353 throw new IllegalArgumentException("fromKey > toKey"); 1354 } else { 1355 if (!fromStart) // type check 1356 m.compare(lo, lo); 1357 if (!toEnd) 1358 m.compare(hi, hi); 1359 } 1360 1361 this.m = m; 1362 this.fromStart = fromStart; 1363 this.lo = lo; 1364 this.loInclusive = loInclusive; 1365 this.toEnd = toEnd; 1366 this.hi = hi; 1367 this.hiInclusive = hiInclusive; 1368 } 1369 1370 // internal utilities 1371 1372 final boolean tooLow(Object key) { 1373 if (!fromStart) { 1374 int c = m.compare(key, lo); 1375 if (c < 0 || (c == 0 && !loInclusive)) 1376 return true; 1377 } 1378 return false; 1379 } 1380 1381 final boolean tooHigh(Object key) { 1382 if (!toEnd) { 1383 int c = m.compare(key, hi); 1384 if (c > 0 || (c == 0 && !hiInclusive)) 1385 return true; 1386 } 1387 return false; 1388 } 1389 1390 final boolean inRange(Object key) { 1391 return !tooLow(key) && !tooHigh(key); 1392 } 1393 1394 final boolean inClosedRange(Object key) { 1395 return (fromStart || m.compare(key, lo) >= 0) 1396 && (toEnd || m.compare(hi, key) >= 0); 1397 } 1398 1399 final boolean inRange(Object key, boolean inclusive) { 1400 return inclusive ? inRange(key) : inClosedRange(key); 1401 } 1402 1403 /* 1404 * Absolute versions of relation operations. 1405 * Subclasses map to these using like-named "sub" 1406 * versions that invert senses for descending maps 1407 */ 1408 1409 final TreeMapEntry<K,V> absLowest() { 1410 TreeMapEntry<K,V> e = 1411 (fromStart ? m.getFirstEntry() : 1412 (loInclusive ? m.getCeilingEntry(lo) : 1413 m.getHigherEntry(lo))); 1414 return (e == null || tooHigh(e.key)) ? null : e; 1415 } 1416 1417 final TreeMapEntry<K,V> absHighest() { 1418 TreeMapEntry<K,V> e = 1419 (toEnd ? m.getLastEntry() : 1420 (hiInclusive ? m.getFloorEntry(hi) : 1421 m.getLowerEntry(hi))); 1422 return (e == null || tooLow(e.key)) ? null : e; 1423 } 1424 1425 final TreeMapEntry<K,V> absCeiling(K key) { 1426 if (tooLow(key)) 1427 return absLowest(); 1428 TreeMapEntry<K,V> e = m.getCeilingEntry(key); 1429 return (e == null || tooHigh(e.key)) ? null : e; 1430 } 1431 1432 final TreeMapEntry<K,V> absHigher(K key) { 1433 if (tooLow(key)) 1434 return absLowest(); 1435 TreeMapEntry<K,V> e = m.getHigherEntry(key); 1436 return (e == null || tooHigh(e.key)) ? null : e; 1437 } 1438 1439 final TreeMapEntry<K,V> absFloor(K key) { 1440 if (tooHigh(key)) 1441 return absHighest(); 1442 TreeMapEntry<K,V> e = m.getFloorEntry(key); 1443 return (e == null || tooLow(e.key)) ? null : e; 1444 } 1445 1446 final TreeMapEntry<K,V> absLower(K key) { 1447 if (tooHigh(key)) 1448 return absHighest(); 1449 TreeMapEntry<K,V> e = m.getLowerEntry(key); 1450 return (e == null || tooLow(e.key)) ? null : e; 1451 } 1452 1453 /** Returns the absolute high fence for ascending traversal */ 1454 final TreeMapEntry<K,V> absHighFence() { 1455 return (toEnd ? null : (hiInclusive ? 1456 m.getHigherEntry(hi) : 1457 m.getCeilingEntry(hi))); 1458 } 1459 1460 /** Return the absolute low fence for descending traversal */ 1461 final TreeMapEntry<K,V> absLowFence() { 1462 return (fromStart ? null : (loInclusive ? 1463 m.getLowerEntry(lo) : 1464 m.getFloorEntry(lo))); 1465 } 1466 1467 // Abstract methods defined in ascending vs descending classes 1468 // These relay to the appropriate absolute versions 1469 1470 abstract TreeMapEntry<K,V> subLowest(); 1471 abstract TreeMapEntry<K,V> subHighest(); 1472 abstract TreeMapEntry<K,V> subCeiling(K key); 1473 abstract TreeMapEntry<K,V> subHigher(K key); 1474 abstract TreeMapEntry<K,V> subFloor(K key); 1475 abstract TreeMapEntry<K,V> subLower(K key); 1476 1477 /** Returns ascending iterator from the perspective of this submap */ 1478 abstract Iterator<K> keyIterator(); 1479 1480 abstract Spliterator<K> keySpliterator(); 1481 1482 /** Returns descending iterator from the perspective of this submap */ 1483 abstract Iterator<K> descendingKeyIterator(); 1484 1485 // public methods 1486 1487 public boolean isEmpty() { 1488 return (fromStart && toEnd) ? m.isEmpty() : entrySet().isEmpty(); 1489 } 1490 1491 public int size() { 1492 return (fromStart && toEnd) ? m.size() : entrySet().size(); 1493 } 1494 1495 public final boolean containsKey(Object key) { 1496 return inRange(key) && m.containsKey(key); 1497 } 1498 1499 public final V put(K key, V value) { 1500 if (!inRange(key)) 1501 throw new IllegalArgumentException("key out of range"); 1502 return m.put(key, value); 1503 } 1504 1505 public final V get(Object key) { 1506 return !inRange(key) ? null : m.get(key); 1507 } 1508 1509 public final V remove(Object key) { 1510 return !inRange(key) ? null : m.remove(key); 1511 } 1512 1513 public final Map.Entry<K,V> ceilingEntry(K key) { 1514 return exportEntry(subCeiling(key)); 1515 } 1516 1517 public final K ceilingKey(K key) { 1518 return keyOrNull(subCeiling(key)); 1519 } 1520 1521 public final Map.Entry<K,V> higherEntry(K key) { 1522 return exportEntry(subHigher(key)); 1523 } 1524 1525 public final K higherKey(K key) { 1526 return keyOrNull(subHigher(key)); 1527 } 1528 1529 public final Map.Entry<K,V> floorEntry(K key) { 1530 return exportEntry(subFloor(key)); 1531 } 1532 1533 public final K floorKey(K key) { 1534 return keyOrNull(subFloor(key)); 1535 } 1536 1537 public final Map.Entry<K,V> lowerEntry(K key) { 1538 return exportEntry(subLower(key)); 1539 } 1540 1541 public final K lowerKey(K key) { 1542 return keyOrNull(subLower(key)); 1543 } 1544 1545 public final K firstKey() { 1546 return key(subLowest()); 1547 } 1548 1549 public final K lastKey() { 1550 return key(subHighest()); 1551 } 1552 1553 public final Map.Entry<K,V> firstEntry() { 1554 return exportEntry(subLowest()); 1555 } 1556 1557 public final Map.Entry<K,V> lastEntry() { 1558 return exportEntry(subHighest()); 1559 } 1560 1561 public final Map.Entry<K,V> pollFirstEntry() { 1562 TreeMapEntry<K,V> e = subLowest(); 1563 Map.Entry<K,V> result = exportEntry(e); 1564 if (e != null) 1565 m.deleteEntry(e); 1566 return result; 1567 } 1568 1569 public final Map.Entry<K,V> pollLastEntry() { 1570 TreeMapEntry<K,V> e = subHighest(); 1571 Map.Entry<K,V> result = exportEntry(e); 1572 if (e != null) 1573 m.deleteEntry(e); 1574 return result; 1575 } 1576 1577 // Views 1578 transient NavigableMap<K,V> descendingMapView = null; 1579 transient EntrySetView entrySetView = null; 1580 transient KeySet<K> navigableKeySetView = null; 1581 1582 public final NavigableSet<K> navigableKeySet() { 1583 KeySet<K> nksv = navigableKeySetView; 1584 return (nksv != null) ? nksv : 1585 (navigableKeySetView = new TreeMap.KeySet<>(this)); 1586 } 1587 1588 public final Set<K> keySet() { 1589 return navigableKeySet(); 1590 } 1591 1592 public NavigableSet<K> descendingKeySet() { 1593 return descendingMap().navigableKeySet(); 1594 } 1595 1596 public final SortedMap<K,V> subMap(K fromKey, K toKey) { 1597 return subMap(fromKey, true, toKey, false); 1598 } 1599 1600 public final SortedMap<K,V> headMap(K toKey) { 1601 return headMap(toKey, false); 1602 } 1603 1604 public final SortedMap<K,V> tailMap(K fromKey) { 1605 return tailMap(fromKey, true); 1606 } 1607 1608 // View classes 1609 1610 abstract class EntrySetView extends AbstractSet<Map.Entry<K,V>> { 1611 private transient int size = -1, sizeModCount; 1612 1613 public int size() { 1614 if (fromStart && toEnd) 1615 return m.size(); 1616 if (size == -1 || sizeModCount != m.modCount) { 1617 sizeModCount = m.modCount; 1618 size = 0; 1619 Iterator<?> i = iterator(); 1620 while (i.hasNext()) { 1621 size++; 1622 i.next(); 1623 } 1624 } 1625 return size; 1626 } 1627 1628 public boolean isEmpty() { 1629 TreeMapEntry<K,V> n = absLowest(); 1630 return n == null || tooHigh(n.key); 1631 } 1632 1633 public boolean contains(Object o) { 1634 if (!(o instanceof Map.Entry)) 1635 return false; 1636 Map.Entry<?,?> entry = (Map.Entry<?,?>) o; 1637 Object key = entry.getKey(); 1638 if (!inRange(key)) 1639 return false; 1640 TreeMapEntry<?, ?> node = m.getEntry(key); 1641 return node != null && 1642 valEquals(node.getValue(), entry.getValue()); 1643 } 1644 1645 public boolean remove(Object o) { 1646 if (!(o instanceof Map.Entry)) 1647 return false; 1648 Map.Entry<?,?> entry = (Map.Entry<?,?>) o; 1649 Object key = entry.getKey(); 1650 if (!inRange(key)) 1651 return false; 1652 TreeMapEntry<K,V> node = m.getEntry(key); 1653 if (node!=null && valEquals(node.getValue(), 1654 entry.getValue())) { 1655 m.deleteEntry(node); 1656 return true; 1657 } 1658 return false; 1659 } 1660 } 1661 1662 /** 1663 * Iterators for SubMaps 1664 */ 1665 abstract class SubMapIterator<T> implements Iterator<T> { 1666 TreeMapEntry<K,V> lastReturned; 1667 TreeMapEntry<K,V> next; 1668 final Object fenceKey; 1669 int expectedModCount; 1670 1671 SubMapIterator(TreeMapEntry<K,V> first, 1672 TreeMapEntry<K,V> fence) { 1673 expectedModCount = m.modCount; 1674 lastReturned = null; 1675 next = first; 1676 fenceKey = fence == null ? UNBOUNDED : fence.key; 1677 } 1678 1679 public final boolean hasNext() { 1680 return next != null && next.key != fenceKey; 1681 } 1682 1683 final TreeMapEntry<K,V> nextEntry() { 1684 TreeMapEntry<K,V> e = next; 1685 if (e == null || e.key == fenceKey) 1686 throw new NoSuchElementException(); 1687 if (m.modCount != expectedModCount) 1688 throw new ConcurrentModificationException(); 1689 next = successor(e); 1690 lastReturned = e; 1691 return e; 1692 } 1693 1694 final TreeMapEntry<K,V> prevEntry() { 1695 TreeMapEntry<K,V> e = next; 1696 if (e == null || e.key == fenceKey) 1697 throw new NoSuchElementException(); 1698 if (m.modCount != expectedModCount) 1699 throw new ConcurrentModificationException(); 1700 next = predecessor(e); 1701 lastReturned = e; 1702 return e; 1703 } 1704 1705 final void removeAscending() { 1706 if (lastReturned == null) 1707 throw new IllegalStateException(); 1708 if (m.modCount != expectedModCount) 1709 throw new ConcurrentModificationException(); 1710 // deleted entries are replaced by their successors 1711 if (lastReturned.left != null && lastReturned.right != null) 1712 next = lastReturned; 1713 m.deleteEntry(lastReturned); 1714 lastReturned = null; 1715 expectedModCount = m.modCount; 1716 } 1717 1718 final void removeDescending() { 1719 if (lastReturned == null) 1720 throw new IllegalStateException(); 1721 if (m.modCount != expectedModCount) 1722 throw new ConcurrentModificationException(); 1723 m.deleteEntry(lastReturned); 1724 lastReturned = null; 1725 expectedModCount = m.modCount; 1726 } 1727 1728 } 1729 1730 final class SubMapEntryIterator extends SubMapIterator<Map.Entry<K,V>> { 1731 SubMapEntryIterator(TreeMapEntry<K,V> first, 1732 TreeMapEntry<K,V> fence) { 1733 super(first, fence); 1734 } 1735 public Map.Entry<K,V> next() { 1736 return nextEntry(); 1737 } 1738 public void remove() { 1739 removeAscending(); 1740 } 1741 } 1742 1743 final class DescendingSubMapEntryIterator extends SubMapIterator<Map.Entry<K,V>> { 1744 DescendingSubMapEntryIterator(TreeMapEntry<K,V> last, 1745 TreeMapEntry<K,V> fence) { 1746 super(last, fence); 1747 } 1748 1749 public Map.Entry<K,V> next() { 1750 return prevEntry(); 1751 } 1752 public void remove() { 1753 removeDescending(); 1754 } 1755 } 1756 1757 // Implement minimal Spliterator as KeySpliterator backup 1758 final class SubMapKeyIterator extends SubMapIterator<K> 1759 implements Spliterator<K> { 1760 SubMapKeyIterator(TreeMapEntry<K,V> first, 1761 TreeMapEntry<K,V> fence) { 1762 super(first, fence); 1763 } 1764 public K next() { 1765 return nextEntry().key; 1766 } 1767 public void remove() { 1768 removeAscending(); 1769 } 1770 public Spliterator<K> trySplit() { 1771 return null; 1772 } 1773 public void forEachRemaining(Consumer<? super K> action) { 1774 while (hasNext()) 1775 action.accept(next()); 1776 } 1777 public boolean tryAdvance(Consumer<? super K> action) { 1778 if (hasNext()) { 1779 action.accept(next()); 1780 return true; 1781 } 1782 return false; 1783 } 1784 public long estimateSize() { 1785 return Long.MAX_VALUE; 1786 } 1787 public int characteristics() { 1788 return Spliterator.DISTINCT | Spliterator.ORDERED | 1789 Spliterator.SORTED; 1790 } 1791 public final Comparator<? super K> getComparator() { 1792 return NavigableSubMap.this.comparator(); 1793 } 1794 } 1795 1796 final class DescendingSubMapKeyIterator extends SubMapIterator<K> 1797 implements Spliterator<K> { 1798 DescendingSubMapKeyIterator(TreeMapEntry<K,V> last, 1799 TreeMapEntry<K,V> fence) { 1800 super(last, fence); 1801 } 1802 public K next() { 1803 return prevEntry().key; 1804 } 1805 public void remove() { 1806 removeDescending(); 1807 } 1808 public Spliterator<K> trySplit() { 1809 return null; 1810 } 1811 public void forEachRemaining(Consumer<? super K> action) { 1812 while (hasNext()) 1813 action.accept(next()); 1814 } 1815 public boolean tryAdvance(Consumer<? super K> action) { 1816 if (hasNext()) { 1817 action.accept(next()); 1818 return true; 1819 } 1820 return false; 1821 } 1822 public long estimateSize() { 1823 return Long.MAX_VALUE; 1824 } 1825 public int characteristics() { 1826 return Spliterator.DISTINCT | Spliterator.ORDERED; 1827 } 1828 } 1829 } 1830 1831 /** 1832 * @serial include 1833 */ 1834 static final class AscendingSubMap<K,V> extends NavigableSubMap<K,V> { 1835 private static final long serialVersionUID = 912986545866124060L; 1836 1837 AscendingSubMap(TreeMap<K,V> m, 1838 boolean fromStart, K lo, boolean loInclusive, 1839 boolean toEnd, K hi, boolean hiInclusive) { 1840 super(m, fromStart, lo, loInclusive, toEnd, hi, hiInclusive); 1841 } 1842 1843 public Comparator<? super K> comparator() { 1844 return m.comparator(); 1845 } 1846 1847 public NavigableMap<K,V> subMap(K fromKey, boolean fromInclusive, 1848 K toKey, boolean toInclusive) { 1849 if (!inRange(fromKey, fromInclusive)) 1850 throw new IllegalArgumentException("fromKey out of range"); 1851 if (!inRange(toKey, toInclusive)) 1852 throw new IllegalArgumentException("toKey out of range"); 1853 return new AscendingSubMap<>(m, 1854 false, fromKey, fromInclusive, 1855 false, toKey, toInclusive); 1856 } 1857 1858 public NavigableMap<K,V> headMap(K toKey, boolean inclusive) { 1859 /* ----- BEGIN android ----- 1860 Fix for edge cases 1861 if (!inRange(toKey, inclusive)) */ 1862 if (!inRange(toKey) && !(!toEnd && m.compare(toKey, hi) == 0 && 1863 !hiInclusive && !inclusive)) 1864 // ----- END android ----- 1865 throw new IllegalArgumentException("toKey out of range"); 1866 return new AscendingSubMap<>(m, 1867 fromStart, lo, loInclusive, 1868 false, toKey, inclusive); 1869 } 1870 1871 public NavigableMap<K,V> tailMap(K fromKey, boolean inclusive) { 1872 /* ----- BEGIN android ----- 1873 Fix for edge cases 1874 if (!inRange(fromKey, inclusive)) */ 1875 if (!inRange(fromKey) && !(!fromStart && m.compare(fromKey, lo) == 0 && 1876 !loInclusive && !inclusive)) 1877 // ----- END android ----- 1878 throw new IllegalArgumentException("fromKey out of range"); 1879 return new AscendingSubMap<>(m, 1880 false, fromKey, inclusive, 1881 toEnd, hi, hiInclusive); 1882 } 1883 1884 public NavigableMap<K,V> descendingMap() { 1885 NavigableMap<K,V> mv = descendingMapView; 1886 return (mv != null) ? mv : 1887 (descendingMapView = 1888 new DescendingSubMap<>(m, 1889 fromStart, lo, loInclusive, 1890 toEnd, hi, hiInclusive)); 1891 } 1892 1893 Iterator<K> keyIterator() { 1894 return new SubMapKeyIterator(absLowest(), absHighFence()); 1895 } 1896 1897 Spliterator<K> keySpliterator() { 1898 return new SubMapKeyIterator(absLowest(), absHighFence()); 1899 } 1900 1901 Iterator<K> descendingKeyIterator() { 1902 return new DescendingSubMapKeyIterator(absHighest(), absLowFence()); 1903 } 1904 1905 final class AscendingEntrySetView extends EntrySetView { 1906 public Iterator<Map.Entry<K,V>> iterator() { 1907 return new SubMapEntryIterator(absLowest(), absHighFence()); 1908 } 1909 } 1910 1911 public Set<Map.Entry<K,V>> entrySet() { 1912 EntrySetView es = entrySetView; 1913 return (es != null) ? es : new AscendingEntrySetView(); 1914 } 1915 1916 TreeMapEntry<K,V> subLowest() { return absLowest(); } 1917 TreeMapEntry<K,V> subHighest() { return absHighest(); } 1918 TreeMapEntry<K,V> subCeiling(K key) { return absCeiling(key); } 1919 TreeMapEntry<K,V> subHigher(K key) { return absHigher(key); } 1920 TreeMapEntry<K,V> subFloor(K key) { return absFloor(key); } 1921 TreeMapEntry<K,V> subLower(K key) { return absLower(key); } 1922 } 1923 1924 /** 1925 * @serial include 1926 */ 1927 static final class DescendingSubMap<K,V> extends NavigableSubMap<K,V> { 1928 private static final long serialVersionUID = 912986545866120460L; 1929 DescendingSubMap(TreeMap<K,V> m, 1930 boolean fromStart, K lo, boolean loInclusive, 1931 boolean toEnd, K hi, boolean hiInclusive) { 1932 super(m, fromStart, lo, loInclusive, toEnd, hi, hiInclusive); 1933 } 1934 1935 private final Comparator<? super K> reverseComparator = 1936 Collections.reverseOrder(m.comparator); 1937 1938 public Comparator<? super K> comparator() { 1939 return reverseComparator; 1940 } 1941 1942 public NavigableMap<K,V> subMap(K fromKey, boolean fromInclusive, 1943 K toKey, boolean toInclusive) { 1944 if (!inRange(fromKey, fromInclusive)) 1945 throw new IllegalArgumentException("fromKey out of range"); 1946 if (!inRange(toKey, toInclusive)) 1947 throw new IllegalArgumentException("toKey out of range"); 1948 return new DescendingSubMap<>(m, 1949 false, toKey, toInclusive, 1950 false, fromKey, fromInclusive); 1951 } 1952 1953 public NavigableMap<K,V> headMap(K toKey, boolean inclusive) { 1954 /* ----- BEGIN android ----- 1955 Fix for edge cases 1956 if (!inRange(toKey, inclusive)) */ 1957 if (!inRange(toKey) && !(!fromStart && m.compare(toKey, lo) == 0 && 1958 !loInclusive && !inclusive)) 1959 // ----- END android ----- 1960 throw new IllegalArgumentException("toKey out of range"); 1961 return new DescendingSubMap<>(m, 1962 false, toKey, inclusive, 1963 toEnd, hi, hiInclusive); 1964 } 1965 1966 public NavigableMap<K,V> tailMap(K fromKey, boolean inclusive) { 1967 /* ----- BEGIN android ----- 1968 Fix for edge cases 1969 if (!inRange(fromKey, inclusive)) */ 1970 if (!inRange(fromKey) && !(!toEnd && m.compare(fromKey, hi) == 0 && 1971 !hiInclusive && !inclusive)) 1972 // ----- END android ----- 1973 throw new IllegalArgumentException("fromKey out of range"); 1974 return new DescendingSubMap<>(m, 1975 fromStart, lo, loInclusive, 1976 false, fromKey, inclusive); 1977 } 1978 1979 public NavigableMap<K,V> descendingMap() { 1980 NavigableMap<K,V> mv = descendingMapView; 1981 return (mv != null) ? mv : 1982 (descendingMapView = 1983 new AscendingSubMap<>(m, 1984 fromStart, lo, loInclusive, 1985 toEnd, hi, hiInclusive)); 1986 } 1987 1988 Iterator<K> keyIterator() { 1989 return new DescendingSubMapKeyIterator(absHighest(), absLowFence()); 1990 } 1991 1992 Spliterator<K> keySpliterator() { 1993 return new DescendingSubMapKeyIterator(absHighest(), absLowFence()); 1994 } 1995 1996 Iterator<K> descendingKeyIterator() { 1997 return new SubMapKeyIterator(absLowest(), absHighFence()); 1998 } 1999 2000 final class DescendingEntrySetView extends EntrySetView { 2001 public Iterator<Map.Entry<K,V>> iterator() { 2002 return new DescendingSubMapEntryIterator(absHighest(), absLowFence()); 2003 } 2004 } 2005 2006 public Set<Map.Entry<K,V>> entrySet() { 2007 EntrySetView es = entrySetView; 2008 return (es != null) ? es : (entrySetView = new DescendingEntrySetView()); 2009 } 2010 2011 TreeMapEntry<K,V> subLowest() { return absHighest(); } 2012 TreeMapEntry<K,V> subHighest() { return absLowest(); } 2013 TreeMapEntry<K,V> subCeiling(K key) { return absFloor(key); } 2014 TreeMapEntry<K,V> subHigher(K key) { return absLower(key); } 2015 TreeMapEntry<K,V> subFloor(K key) { return absCeiling(key); } 2016 TreeMapEntry<K,V> subLower(K key) { return absHigher(key); } 2017 } 2018 2019 /** 2020 * This class exists solely for the sake of serialization 2021 * compatibility with previous releases of TreeMap that did not 2022 * support NavigableMap. It translates an old-version SubMap into 2023 * a new-version AscendingSubMap. This class is never otherwise 2024 * used. 2025 * 2026 * @serial include 2027 */ 2028 private class SubMap extends AbstractMap<K,V> 2029 implements SortedMap<K,V>, java.io.Serializable { 2030 private static final long serialVersionUID = -6520786458950516097L; 2031 private boolean fromStart = false, toEnd = false; 2032 private K fromKey, toKey; 2033 private Object readResolve() { 2034 return new AscendingSubMap<>(TreeMap.this, 2035 fromStart, fromKey, true, 2036 toEnd, toKey, false); 2037 } 2038 public Set<Map.Entry<K,V>> entrySet() { throw new InternalError(); } 2039 public K lastKey() { throw new InternalError(); } 2040 public K firstKey() { throw new InternalError(); } 2041 public SortedMap<K,V> subMap(K fromKey, K toKey) { throw new InternalError(); } 2042 public SortedMap<K,V> headMap(K toKey) { throw new InternalError(); } 2043 public SortedMap<K,V> tailMap(K fromKey) { throw new InternalError(); } 2044 public Comparator<? super K> comparator() { throw new InternalError(); } 2045 } 2046 2047 2048 // Red-black mechanics 2049 2050 private static final boolean RED = false; 2051 private static final boolean BLACK = true; 2052 2053 /** 2054 * Node in the Tree. Doubles as a means to pass key-value pairs back to 2055 * user (see Map.Entry). 2056 */ 2057 2058 static final class TreeMapEntry<K,V> implements Map.Entry<K,V> { 2059 K key; 2060 V value; 2061 TreeMapEntry<K,V> left = null; 2062 TreeMapEntry<K,V> right = null; 2063 TreeMapEntry<K,V> parent; 2064 boolean color = BLACK; 2065 2066 /** 2067 * Make a new cell with given key, value, and parent, and with 2068 * {@code null} child links, and BLACK color. 2069 */ 2070 TreeMapEntry(K key, V value, TreeMapEntry<K,V> parent) { 2071 this.key = key; 2072 this.value = value; 2073 this.parent = parent; 2074 } 2075 2076 /** 2077 * Returns the key. 2078 * 2079 * @return the key 2080 */ 2081 public K getKey() { 2082 return key; 2083 } 2084 2085 /** 2086 * Returns the value associated with the key. 2087 * 2088 * @return the value associated with the key 2089 */ 2090 public V getValue() { 2091 return value; 2092 } 2093 2094 /** 2095 * Replaces the value currently associated with the key with the given 2096 * value. 2097 * 2098 * @return the value associated with the key before this method was 2099 * called 2100 */ 2101 public V setValue(V value) { 2102 V oldValue = this.value; 2103 this.value = value; 2104 return oldValue; 2105 } 2106 2107 public boolean equals(Object o) { 2108 if (!(o instanceof Map.Entry)) 2109 return false; 2110 Map.Entry<?,?> e = (Map.Entry<?,?>)o; 2111 2112 return valEquals(key,e.getKey()) && valEquals(value,e.getValue()); 2113 } 2114 2115 public int hashCode() { 2116 int keyHash = (key==null ? 0 : key.hashCode()); 2117 int valueHash = (value==null ? 0 : value.hashCode()); 2118 return keyHash ^ valueHash; 2119 } 2120 2121 public String toString() { 2122 return key + "=" + value; 2123 } 2124 } 2125 2126 /** 2127 * Returns the first Entry in the TreeMap (according to the TreeMap's 2128 * key-sort function). Returns null if the TreeMap is empty. 2129 */ 2130 final TreeMapEntry<K,V> getFirstEntry() { 2131 TreeMapEntry<K,V> p = root; 2132 if (p != null) 2133 while (p.left != null) 2134 p = p.left; 2135 return p; 2136 } 2137 2138 /** 2139 * Returns the last Entry in the TreeMap (according to the TreeMap's 2140 * key-sort function). Returns null if the TreeMap is empty. 2141 */ 2142 final TreeMapEntry<K,V> getLastEntry() { 2143 TreeMapEntry<K,V> p = root; 2144 if (p != null) 2145 while (p.right != null) 2146 p = p.right; 2147 return p; 2148 } 2149 2150 /** 2151 * Returns the successor of the specified Entry, or null if no such. 2152 */ 2153 static <K,V> TreeMapEntry<K,V> successor(TreeMapEntry<K,V> t) { 2154 if (t == null) 2155 return null; 2156 else if (t.right != null) { 2157 TreeMapEntry<K,V> p = t.right; 2158 while (p.left != null) 2159 p = p.left; 2160 return p; 2161 } else { 2162 TreeMapEntry<K,V> p = t.parent; 2163 TreeMapEntry<K,V> ch = t; 2164 while (p != null && ch == p.right) { 2165 ch = p; 2166 p = p.parent; 2167 } 2168 return p; 2169 } 2170 } 2171 2172 /** 2173 * Returns the predecessor of the specified Entry, or null if no such. 2174 */ 2175 static <K,V> TreeMapEntry<K,V> predecessor(TreeMapEntry<K,V> t) { 2176 if (t == null) 2177 return null; 2178 else if (t.left != null) { 2179 TreeMapEntry<K,V> p = t.left; 2180 while (p.right != null) 2181 p = p.right; 2182 return p; 2183 } else { 2184 TreeMapEntry<K,V> p = t.parent; 2185 TreeMapEntry<K,V> ch = t; 2186 while (p != null && ch == p.left) { 2187 ch = p; 2188 p = p.parent; 2189 } 2190 return p; 2191 } 2192 } 2193 2194 /** 2195 * Balancing operations. 2196 * 2197 * Implementations of rebalancings during insertion and deletion are 2198 * slightly different than the CLR version. Rather than using dummy 2199 * nilnodes, we use a set of accessors that deal properly with null. They 2200 * are used to avoid messiness surrounding nullness checks in the main 2201 * algorithms. 2202 */ 2203 2204 private static <K,V> boolean colorOf(TreeMapEntry<K,V> p) { 2205 return (p == null ? BLACK : p.color); 2206 } 2207 2208 private static <K,V> TreeMapEntry<K,V> parentOf(TreeMapEntry<K,V> p) { 2209 return (p == null ? null: p.parent); 2210 } 2211 2212 private static <K,V> void setColor(TreeMapEntry<K,V> p, boolean c) { 2213 if (p != null) 2214 p.color = c; 2215 } 2216 2217 private static <K,V> TreeMapEntry<K,V> leftOf(TreeMapEntry<K,V> p) { 2218 return (p == null) ? null: p.left; 2219 } 2220 2221 private static <K,V> TreeMapEntry<K,V> rightOf(TreeMapEntry<K,V> p) { 2222 return (p == null) ? null: p.right; 2223 } 2224 2225 /** From CLR */ 2226 private void rotateLeft(TreeMapEntry<K,V> p) { 2227 if (p != null) { 2228 TreeMapEntry<K,V> r = p.right; 2229 p.right = r.left; 2230 if (r.left != null) 2231 r.left.parent = p; 2232 r.parent = p.parent; 2233 if (p.parent == null) 2234 root = r; 2235 else if (p.parent.left == p) 2236 p.parent.left = r; 2237 else 2238 p.parent.right = r; 2239 r.left = p; 2240 p.parent = r; 2241 } 2242 } 2243 2244 /** From CLR */ 2245 private void rotateRight(TreeMapEntry<K,V> p) { 2246 if (p != null) { 2247 TreeMapEntry<K,V> l = p.left; 2248 p.left = l.right; 2249 if (l.right != null) l.right.parent = p; 2250 l.parent = p.parent; 2251 if (p.parent == null) 2252 root = l; 2253 else if (p.parent.right == p) 2254 p.parent.right = l; 2255 else p.parent.left = l; 2256 l.right = p; 2257 p.parent = l; 2258 } 2259 } 2260 2261 /** From CLR */ 2262 private void fixAfterInsertion(TreeMapEntry<K,V> x) { 2263 x.color = RED; 2264 2265 while (x != null && x != root && x.parent.color == RED) { 2266 if (parentOf(x) == leftOf(parentOf(parentOf(x)))) { 2267 TreeMapEntry<K,V> y = rightOf(parentOf(parentOf(x))); 2268 if (colorOf(y) == RED) { 2269 setColor(parentOf(x), BLACK); 2270 setColor(y, BLACK); 2271 setColor(parentOf(parentOf(x)), RED); 2272 x = parentOf(parentOf(x)); 2273 } else { 2274 if (x == rightOf(parentOf(x))) { 2275 x = parentOf(x); 2276 rotateLeft(x); 2277 } 2278 setColor(parentOf(x), BLACK); 2279 setColor(parentOf(parentOf(x)), RED); 2280 rotateRight(parentOf(parentOf(x))); 2281 } 2282 } else { 2283 TreeMapEntry<K,V> y = leftOf(parentOf(parentOf(x))); 2284 if (colorOf(y) == RED) { 2285 setColor(parentOf(x), BLACK); 2286 setColor(y, BLACK); 2287 setColor(parentOf(parentOf(x)), RED); 2288 x = parentOf(parentOf(x)); 2289 } else { 2290 if (x == leftOf(parentOf(x))) { 2291 x = parentOf(x); 2292 rotateRight(x); 2293 } 2294 setColor(parentOf(x), BLACK); 2295 setColor(parentOf(parentOf(x)), RED); 2296 rotateLeft(parentOf(parentOf(x))); 2297 } 2298 } 2299 } 2300 root.color = BLACK; 2301 } 2302 2303 /** 2304 * Delete node p, and then rebalance the tree. 2305 */ 2306 private void deleteEntry(TreeMapEntry<K,V> p) { 2307 modCount++; 2308 size--; 2309 2310 // If strictly internal, copy successor's element to p and then make p 2311 // point to successor. 2312 if (p.left != null && p.right != null) { 2313 TreeMapEntry<K,V> s = successor(p); 2314 p.key = s.key; 2315 p.value = s.value; 2316 p = s; 2317 } // p has 2 children 2318 2319 // Start fixup at replacement node, if it exists. 2320 TreeMapEntry<K,V> replacement = (p.left != null ? p.left : p.right); 2321 2322 if (replacement != null) { 2323 // Link replacement to parent 2324 replacement.parent = p.parent; 2325 if (p.parent == null) 2326 root = replacement; 2327 else if (p == p.parent.left) 2328 p.parent.left = replacement; 2329 else 2330 p.parent.right = replacement; 2331 2332 // Null out links so they are OK to use by fixAfterDeletion. 2333 p.left = p.right = p.parent = null; 2334 2335 // Fix replacement 2336 if (p.color == BLACK) 2337 fixAfterDeletion(replacement); 2338 } else if (p.parent == null) { // return if we are the only node. 2339 root = null; 2340 } else { // No children. Use self as phantom replacement and unlink. 2341 if (p.color == BLACK) 2342 fixAfterDeletion(p); 2343 2344 if (p.parent != null) { 2345 if (p == p.parent.left) 2346 p.parent.left = null; 2347 else if (p == p.parent.right) 2348 p.parent.right = null; 2349 p.parent = null; 2350 } 2351 } 2352 } 2353 2354 /** From CLR */ 2355 private void fixAfterDeletion(TreeMapEntry<K,V> x) { 2356 while (x != root && colorOf(x) == BLACK) { 2357 if (x == leftOf(parentOf(x))) { 2358 TreeMapEntry<K,V> sib = rightOf(parentOf(x)); 2359 2360 if (colorOf(sib) == RED) { 2361 setColor(sib, BLACK); 2362 setColor(parentOf(x), RED); 2363 rotateLeft(parentOf(x)); 2364 sib = rightOf(parentOf(x)); 2365 } 2366 2367 if (colorOf(leftOf(sib)) == BLACK && 2368 colorOf(rightOf(sib)) == BLACK) { 2369 setColor(sib, RED); 2370 x = parentOf(x); 2371 } else { 2372 if (colorOf(rightOf(sib)) == BLACK) { 2373 setColor(leftOf(sib), BLACK); 2374 setColor(sib, RED); 2375 rotateRight(sib); 2376 sib = rightOf(parentOf(x)); 2377 } 2378 setColor(sib, colorOf(parentOf(x))); 2379 setColor(parentOf(x), BLACK); 2380 setColor(rightOf(sib), BLACK); 2381 rotateLeft(parentOf(x)); 2382 x = root; 2383 } 2384 } else { // symmetric 2385 TreeMapEntry<K,V> sib = leftOf(parentOf(x)); 2386 2387 if (colorOf(sib) == RED) { 2388 setColor(sib, BLACK); 2389 setColor(parentOf(x), RED); 2390 rotateRight(parentOf(x)); 2391 sib = leftOf(parentOf(x)); 2392 } 2393 2394 if (colorOf(rightOf(sib)) == BLACK && 2395 colorOf(leftOf(sib)) == BLACK) { 2396 setColor(sib, RED); 2397 x = parentOf(x); 2398 } else { 2399 if (colorOf(leftOf(sib)) == BLACK) { 2400 setColor(rightOf(sib), BLACK); 2401 setColor(sib, RED); 2402 rotateLeft(sib); 2403 sib = leftOf(parentOf(x)); 2404 } 2405 setColor(sib, colorOf(parentOf(x))); 2406 setColor(parentOf(x), BLACK); 2407 setColor(leftOf(sib), BLACK); 2408 rotateRight(parentOf(x)); 2409 x = root; 2410 } 2411 } 2412 } 2413 2414 setColor(x, BLACK); 2415 } 2416 2417 private static final long serialVersionUID = 919286545866124006L; 2418 2419 /** 2420 * Save the state of the {@code TreeMap} instance to a stream (i.e., 2421 * serialize it). 2422 * 2423 * @serialData The <em>size</em> of the TreeMap (the number of key-value 2424 * mappings) is emitted (int), followed by the key (Object) 2425 * and value (Object) for each key-value mapping represented 2426 * by the TreeMap. The key-value mappings are emitted in 2427 * key-order (as determined by the TreeMap's Comparator, 2428 * or by the keys' natural ordering if the TreeMap has no 2429 * Comparator). 2430 */ 2431 private void writeObject(java.io.ObjectOutputStream s) 2432 throws java.io.IOException { 2433 // Write out the Comparator and any hidden stuff 2434 s.defaultWriteObject(); 2435 2436 // Write out size (number of Mappings) 2437 s.writeInt(size); 2438 2439 // Write out keys and values (alternating) 2440 for (Iterator<Map.Entry<K,V>> i = entrySet().iterator(); i.hasNext(); ) { 2441 Map.Entry<K,V> e = i.next(); 2442 s.writeObject(e.getKey()); 2443 s.writeObject(e.getValue()); 2444 } 2445 } 2446 2447 /** 2448 * Reconstitute the {@code TreeMap} instance from a stream (i.e., 2449 * deserialize it). 2450 */ 2451 private void readObject(final java.io.ObjectInputStream s) 2452 throws java.io.IOException, ClassNotFoundException { 2453 // Read in the Comparator and any hidden stuff 2454 s.defaultReadObject(); 2455 2456 // Read in size 2457 int size = s.readInt(); 2458 2459 buildFromSorted(size, null, s, null); 2460 } 2461 2462 /** Intended to be called only from TreeSet.readObject */ 2463 void readTreeSet(int size, java.io.ObjectInputStream s, V defaultVal) 2464 throws java.io.IOException, ClassNotFoundException { 2465 buildFromSorted(size, null, s, defaultVal); 2466 } 2467 2468 /** Intended to be called only from TreeSet.addAll */ 2469 void addAllForTreeSet(SortedSet<? extends K> set, V defaultVal) { 2470 try { 2471 buildFromSorted(set.size(), set.iterator(), null, defaultVal); 2472 } catch (java.io.IOException cannotHappen) { 2473 } catch (ClassNotFoundException cannotHappen) { 2474 } 2475 } 2476 2477 2478 /** 2479 * Linear time tree building algorithm from sorted data. Can accept keys 2480 * and/or values from iterator or stream. This leads to too many 2481 * parameters, but seems better than alternatives. The four formats 2482 * that this method accepts are: 2483 * 2484 * 1) An iterator of Map.Entries. (it != null, defaultVal == null). 2485 * 2) An iterator of keys. (it != null, defaultVal != null). 2486 * 3) A stream of alternating serialized keys and values. 2487 * (it == null, defaultVal == null). 2488 * 4) A stream of serialized keys. (it == null, defaultVal != null). 2489 * 2490 * It is assumed that the comparator of the TreeMap is already set prior 2491 * to calling this method. 2492 * 2493 * @param size the number of keys (or key-value pairs) to be read from 2494 * the iterator or stream 2495 * @param it If non-null, new entries are created from entries 2496 * or keys read from this iterator. 2497 * @param str If non-null, new entries are created from keys and 2498 * possibly values read from this stream in serialized form. 2499 * Exactly one of it and str should be non-null. 2500 * @param defaultVal if non-null, this default value is used for 2501 * each value in the map. If null, each value is read from 2502 * iterator or stream, as described above. 2503 * @throws java.io.IOException propagated from stream reads. This cannot 2504 * occur if str is null. 2505 * @throws ClassNotFoundException propagated from readObject. 2506 * This cannot occur if str is null. 2507 */ 2508 private void buildFromSorted(int size, Iterator<?> it, 2509 java.io.ObjectInputStream str, 2510 V defaultVal) 2511 throws java.io.IOException, ClassNotFoundException { 2512 this.size = size; 2513 root = buildFromSorted(0, 0, size-1, computeRedLevel(size), 2514 it, str, defaultVal); 2515 } 2516 2517 /** 2518 * Recursive "helper method" that does the real work of the 2519 * previous method. Identically named parameters have 2520 * identical definitions. Additional parameters are documented below. 2521 * It is assumed that the comparator and size fields of the TreeMap are 2522 * already set prior to calling this method. (It ignores both fields.) 2523 * 2524 * @param level the current level of tree. Initial call should be 0. 2525 * @param lo the first element index of this subtree. Initial should be 0. 2526 * @param hi the last element index of this subtree. Initial should be 2527 * size-1. 2528 * @param redLevel the level at which nodes should be red. 2529 * Must be equal to computeRedLevel for tree of this size. 2530 */ 2531 @SuppressWarnings("unchecked") 2532 private final TreeMapEntry<K,V> buildFromSorted(int level, int lo, int hi, 2533 int redLevel, 2534 Iterator<?> it, 2535 java.io.ObjectInputStream str, 2536 V defaultVal) 2537 throws java.io.IOException, ClassNotFoundException { 2538 /* 2539 * Strategy: The root is the middlemost element. To get to it, we 2540 * have to first recursively construct the entire left subtree, 2541 * so as to grab all of its elements. We can then proceed with right 2542 * subtree. 2543 * 2544 * The lo and hi arguments are the minimum and maximum 2545 * indices to pull out of the iterator or stream for current subtree. 2546 * They are not actually indexed, we just proceed sequentially, 2547 * ensuring that items are extracted in corresponding order. 2548 */ 2549 2550 if (hi < lo) return null; 2551 2552 int mid = (lo + hi) >>> 1; 2553 2554 TreeMapEntry<K,V> left = null; 2555 if (lo < mid) 2556 left = buildFromSorted(level+1, lo, mid - 1, redLevel, 2557 it, str, defaultVal); 2558 2559 // extract key and/or value from iterator or stream 2560 K key; 2561 V value; 2562 if (it != null) { 2563 if (defaultVal==null) { 2564 Map.Entry<K,V> entry = (Map.Entry<K,V>)it.next(); 2565 key = entry.getKey(); 2566 value = entry.getValue(); 2567 } else { 2568 key = (K)it.next(); 2569 value = defaultVal; 2570 } 2571 } else { // use stream 2572 key = (K) str.readObject(); 2573 value = (defaultVal != null ? defaultVal : (V) str.readObject()); 2574 } 2575 2576 TreeMapEntry<K,V> middle = new TreeMapEntry<>(key, value, null); 2577 2578 // color nodes in non-full bottommost level red 2579 if (level == redLevel) 2580 middle.color = RED; 2581 2582 if (left != null) { 2583 middle.left = left; 2584 left.parent = middle; 2585 } 2586 2587 if (mid < hi) { 2588 TreeMapEntry<K,V> right = buildFromSorted(level+1, mid+1, hi, redLevel, 2589 it, str, defaultVal); 2590 middle.right = right; 2591 right.parent = middle; 2592 } 2593 2594 return middle; 2595 } 2596 2597 /** 2598 * Find the level down to which to assign all nodes BLACK. This is the 2599 * last `full' level of the complete binary tree produced by 2600 * buildTree. The remaining nodes are colored RED. (This makes a `nice' 2601 * set of color assignments wrt future insertions.) This level number is 2602 * computed by finding the number of splits needed to reach the zeroeth 2603 * node. (The answer is ~lg(N), but in any case must be computed by same 2604 * quick O(lg(N)) loop.) 2605 */ 2606 private static int computeRedLevel(int sz) { 2607 int level = 0; 2608 for (int m = sz - 1; m >= 0; m = m / 2 - 1) 2609 level++; 2610 return level; 2611 } 2612 2613 /** 2614 * Currently, we support Spliterator-based versions only for the 2615 * full map, in either plain of descending form, otherwise relying 2616 * on defaults because size estimation for submaps would dominate 2617 * costs. The type tests needed to check these for key views are 2618 * not very nice but avoid disrupting existing class 2619 * structures. Callers must use plain default spliterators if this 2620 * returns null. 2621 */ 2622 static <K> Spliterator<K> keySpliteratorFor(NavigableMap<K,?> m) { 2623 if (m instanceof TreeMap) { 2624 @SuppressWarnings("unchecked") TreeMap<K,Object> t = 2625 (TreeMap<K,Object>) m; 2626 return t.keySpliterator(); 2627 } 2628 if (m instanceof DescendingSubMap) { 2629 @SuppressWarnings("unchecked") DescendingSubMap<K,?> dm = 2630 (DescendingSubMap<K,?>) m; 2631 TreeMap<K,?> tm = dm.m; 2632 if (dm == tm.descendingMap) { 2633 @SuppressWarnings("unchecked") TreeMap<K,Object> t = 2634 (TreeMap<K,Object>) tm; 2635 return t.descendingKeySpliterator(); 2636 } 2637 } 2638 @SuppressWarnings("unchecked") NavigableSubMap<K,?> sm = 2639 (NavigableSubMap<K,?>) m; 2640 return sm.keySpliterator(); 2641 } 2642 2643 final Spliterator<K> keySpliterator() { 2644 return new KeySpliterator<K,V>(this, null, null, 0, -1, 0); 2645 } 2646 2647 final Spliterator<K> descendingKeySpliterator() { 2648 return new DescendingKeySpliterator<K,V>(this, null, null, 0, -2, 0); 2649 } 2650 2651 /** 2652 * Base class for spliterators. Iteration starts at a given 2653 * origin and continues up to but not including a given fence (or 2654 * null for end). At top-level, for ascending cases, the first 2655 * split uses the root as left-fence/right-origin. From there, 2656 * right-hand splits replace the current fence with its left 2657 * child, also serving as origin for the split-off spliterator. 2658 * Left-hands are symmetric. Descending versions place the origin 2659 * at the end and invert ascending split rules. This base class 2660 * is non-commital about directionality, or whether the top-level 2661 * spliterator covers the whole tree. This means that the actual 2662 * split mechanics are located in subclasses. Some of the subclass 2663 * trySplit methods are identical (except for return types), but 2664 * not nicely factorable. 2665 * 2666 * Currently, subclass versions exist only for the full map 2667 * (including descending keys via its descendingMap). Others are 2668 * possible but currently not worthwhile because submaps require 2669 * O(n) computations to determine size, which substantially limits 2670 * potential speed-ups of using custom Spliterators versus default 2671 * mechanics. 2672 * 2673 * To boostrap initialization, external constructors use 2674 * negative size estimates: -1 for ascend, -2 for descend. 2675 */ 2676 static class TreeMapSpliterator<K,V> { 2677 final TreeMap<K,V> tree; 2678 TreeMapEntry<K,V> current; // traverser; initially first node in range 2679 TreeMapEntry<K,V> fence; // one past last, or null 2680 int side; // 0: top, -1: is a left split, +1: right 2681 int est; // size estimate (exact only for top-level) 2682 int expectedModCount; // for CME checks 2683 2684 TreeMapSpliterator(TreeMap<K,V> tree, 2685 TreeMapEntry<K,V> origin, TreeMapEntry<K,V> fence, 2686 int side, int est, int expectedModCount) { 2687 this.tree = tree; 2688 this.current = origin; 2689 this.fence = fence; 2690 this.side = side; 2691 this.est = est; 2692 this.expectedModCount = expectedModCount; 2693 } 2694 2695 final int getEstimate() { // force initialization 2696 int s; TreeMap<K,V> t; 2697 if ((s = est) < 0) { 2698 if ((t = tree) != null) { 2699 current = (s == -1) ? t.getFirstEntry() : t.getLastEntry(); 2700 s = est = t.size; 2701 expectedModCount = t.modCount; 2702 } 2703 else 2704 s = est = 0; 2705 } 2706 return s; 2707 } 2708 2709 public final long estimateSize() { 2710 return (long)getEstimate(); 2711 } 2712 } 2713 2714 static final class KeySpliterator<K,V> 2715 extends TreeMapSpliterator<K,V> 2716 implements Spliterator<K> { 2717 KeySpliterator(TreeMap<K,V> tree, 2718 TreeMapEntry<K,V> origin, TreeMapEntry<K,V> fence, 2719 int side, int est, int expectedModCount) { 2720 super(tree, origin, fence, side, est, expectedModCount); 2721 } 2722 2723 public KeySpliterator<K,V> trySplit() { 2724 if (est < 0) 2725 getEstimate(); // force initialization 2726 int d = side; 2727 TreeMapEntry<K,V> e = current, f = fence, 2728 s = ((e == null || e == f) ? null : // empty 2729 (d == 0) ? tree.root : // was top 2730 (d > 0) ? e.right : // was right 2731 (d < 0 && f != null) ? f.left : // was left 2732 null); 2733 if (s != null && s != e && s != f && 2734 tree.compare(e.key, s.key) < 0) { // e not already past s 2735 side = 1; 2736 return new KeySpliterator<> 2737 (tree, e, current = s, -1, est >>>= 1, expectedModCount); 2738 } 2739 return null; 2740 } 2741 2742 public void forEachRemaining(Consumer<? super K> action) { 2743 if (action == null) 2744 throw new NullPointerException(); 2745 if (est < 0) 2746 getEstimate(); // force initialization 2747 TreeMapEntry<K,V> f = fence, e, p, pl; 2748 if ((e = current) != null && e != f) { 2749 current = f; // exhaust 2750 do { 2751 action.accept(e.key); 2752 if ((p = e.right) != null) { 2753 while ((pl = p.left) != null) 2754 p = pl; 2755 } 2756 else { 2757 while ((p = e.parent) != null && e == p.right) 2758 e = p; 2759 } 2760 } while ((e = p) != null && e != f); 2761 if (tree.modCount != expectedModCount) 2762 throw new ConcurrentModificationException(); 2763 } 2764 } 2765 2766 public boolean tryAdvance(Consumer<? super K> action) { 2767 TreeMapEntry<K,V> e; 2768 if (action == null) 2769 throw new NullPointerException(); 2770 if (est < 0) 2771 getEstimate(); // force initialization 2772 if ((e = current) == null || e == fence) 2773 return false; 2774 current = successor(e); 2775 action.accept(e.key); 2776 if (tree.modCount != expectedModCount) 2777 throw new ConcurrentModificationException(); 2778 return true; 2779 } 2780 2781 public int characteristics() { 2782 return (side == 0 ? Spliterator.SIZED : 0) | 2783 Spliterator.DISTINCT | Spliterator.SORTED | Spliterator.ORDERED; 2784 } 2785 2786 public final Comparator<? super K> getComparator() { 2787 return tree.comparator; 2788 } 2789 2790 } 2791 2792 static final class DescendingKeySpliterator<K,V> 2793 extends TreeMapSpliterator<K,V> 2794 implements Spliterator<K> { 2795 DescendingKeySpliterator(TreeMap<K,V> tree, 2796 TreeMapEntry<K,V> origin, TreeMapEntry<K,V> fence, 2797 int side, int est, int expectedModCount) { 2798 super(tree, origin, fence, side, est, expectedModCount); 2799 } 2800 2801 public DescendingKeySpliterator<K,V> trySplit() { 2802 if (est < 0) 2803 getEstimate(); // force initialization 2804 int d = side; 2805 TreeMapEntry<K,V> e = current, f = fence, 2806 s = ((e == null || e == f) ? null : // empty 2807 (d == 0) ? tree.root : // was top 2808 (d < 0) ? e.left : // was left 2809 (d > 0 && f != null) ? f.right : // was right 2810 null); 2811 if (s != null && s != e && s != f && 2812 tree.compare(e.key, s.key) > 0) { // e not already past s 2813 side = 1; 2814 return new DescendingKeySpliterator<> 2815 (tree, e, current = s, -1, est >>>= 1, expectedModCount); 2816 } 2817 return null; 2818 } 2819 2820 public void forEachRemaining(Consumer<? super K> action) { 2821 if (action == null) 2822 throw new NullPointerException(); 2823 if (est < 0) 2824 getEstimate(); // force initialization 2825 TreeMapEntry<K,V> f = fence, e, p, pr; 2826 if ((e = current) != null && e != f) { 2827 current = f; // exhaust 2828 do { 2829 action.accept(e.key); 2830 if ((p = e.left) != null) { 2831 while ((pr = p.right) != null) 2832 p = pr; 2833 } 2834 else { 2835 while ((p = e.parent) != null && e == p.left) 2836 e = p; 2837 } 2838 } while ((e = p) != null && e != f); 2839 if (tree.modCount != expectedModCount) 2840 throw new ConcurrentModificationException(); 2841 } 2842 } 2843 2844 public boolean tryAdvance(Consumer<? super K> action) { 2845 TreeMapEntry<K,V> e; 2846 if (action == null) 2847 throw new NullPointerException(); 2848 if (est < 0) 2849 getEstimate(); // force initialization 2850 if ((e = current) == null || e == fence) 2851 return false; 2852 current = predecessor(e); 2853 action.accept(e.key); 2854 if (tree.modCount != expectedModCount) 2855 throw new ConcurrentModificationException(); 2856 return true; 2857 } 2858 2859 public int characteristics() { 2860 return (side == 0 ? Spliterator.SIZED : 0) | 2861 Spliterator.DISTINCT | Spliterator.ORDERED; 2862 } 2863 } 2864 2865 static final class ValueSpliterator<K,V> 2866 extends TreeMapSpliterator<K,V> 2867 implements Spliterator<V> { 2868 ValueSpliterator(TreeMap<K,V> tree, 2869 TreeMapEntry<K,V> origin, TreeMapEntry<K,V> fence, 2870 int side, int est, int expectedModCount) { 2871 super(tree, origin, fence, side, est, expectedModCount); 2872 } 2873 2874 public ValueSpliterator<K,V> trySplit() { 2875 if (est < 0) 2876 getEstimate(); // force initialization 2877 int d = side; 2878 TreeMapEntry<K,V> e = current, f = fence, 2879 s = ((e == null || e == f) ? null : // empty 2880 (d == 0) ? tree.root : // was top 2881 (d > 0) ? e.right : // was right 2882 (d < 0 && f != null) ? f.left : // was left 2883 null); 2884 if (s != null && s != e && s != f && 2885 tree.compare(e.key, s.key) < 0) { // e not already past s 2886 side = 1; 2887 return new ValueSpliterator<> 2888 (tree, e, current = s, -1, est >>>= 1, expectedModCount); 2889 } 2890 return null; 2891 } 2892 2893 public void forEachRemaining(Consumer<? super V> action) { 2894 if (action == null) 2895 throw new NullPointerException(); 2896 if (est < 0) 2897 getEstimate(); // force initialization 2898 TreeMapEntry<K,V> f = fence, e, p, pl; 2899 if ((e = current) != null && e != f) { 2900 current = f; // exhaust 2901 do { 2902 action.accept(e.value); 2903 if ((p = e.right) != null) { 2904 while ((pl = p.left) != null) 2905 p = pl; 2906 } 2907 else { 2908 while ((p = e.parent) != null && e == p.right) 2909 e = p; 2910 } 2911 } while ((e = p) != null && e != f); 2912 if (tree.modCount != expectedModCount) 2913 throw new ConcurrentModificationException(); 2914 } 2915 } 2916 2917 public boolean tryAdvance(Consumer<? super V> action) { 2918 TreeMapEntry<K,V> e; 2919 if (action == null) 2920 throw new NullPointerException(); 2921 if (est < 0) 2922 getEstimate(); // force initialization 2923 if ((e = current) == null || e == fence) 2924 return false; 2925 current = successor(e); 2926 action.accept(e.value); 2927 if (tree.modCount != expectedModCount) 2928 throw new ConcurrentModificationException(); 2929 return true; 2930 } 2931 2932 public int characteristics() { 2933 return (side == 0 ? Spliterator.SIZED : 0) | Spliterator.ORDERED; 2934 } 2935 } 2936 2937 static final class EntrySpliterator<K,V> 2938 extends TreeMapSpliterator<K,V> 2939 implements Spliterator<Map.Entry<K,V>> { 2940 EntrySpliterator(TreeMap<K,V> tree, 2941 TreeMapEntry<K,V> origin, TreeMapEntry<K,V> fence, 2942 int side, int est, int expectedModCount) { 2943 super(tree, origin, fence, side, est, expectedModCount); 2944 } 2945 2946 public EntrySpliterator<K,V> trySplit() { 2947 if (est < 0) 2948 getEstimate(); // force initialization 2949 int d = side; 2950 TreeMapEntry<K,V> e = current, f = fence, 2951 s = ((e == null || e == f) ? null : // empty 2952 (d == 0) ? tree.root : // was top 2953 (d > 0) ? e.right : // was right 2954 (d < 0 && f != null) ? f.left : // was left 2955 null); 2956 if (s != null && s != e && s != f && 2957 tree.compare(e.key, s.key) < 0) { // e not already past s 2958 side = 1; 2959 return new EntrySpliterator<> 2960 (tree, e, current = s, -1, est >>>= 1, expectedModCount); 2961 } 2962 return null; 2963 } 2964 2965 public void forEachRemaining(Consumer<? super Map.Entry<K, V>> action) { 2966 if (action == null) 2967 throw new NullPointerException(); 2968 if (est < 0) 2969 getEstimate(); // force initialization 2970 TreeMapEntry<K,V> f = fence, e, p, pl; 2971 if ((e = current) != null && e != f) { 2972 current = f; // exhaust 2973 do { 2974 action.accept(e); 2975 if ((p = e.right) != null) { 2976 while ((pl = p.left) != null) 2977 p = pl; 2978 } 2979 else { 2980 while ((p = e.parent) != null && e == p.right) 2981 e = p; 2982 } 2983 } while ((e = p) != null && e != f); 2984 if (tree.modCount != expectedModCount) 2985 throw new ConcurrentModificationException(); 2986 } 2987 } 2988 2989 public boolean tryAdvance(Consumer<? super Map.Entry<K,V>> action) { 2990 TreeMapEntry<K,V> e; 2991 if (action == null) 2992 throw new NullPointerException(); 2993 if (est < 0) 2994 getEstimate(); // force initialization 2995 if ((e = current) == null || e == fence) 2996 return false; 2997 current = successor(e); 2998 action.accept(e); 2999 if (tree.modCount != expectedModCount) 3000 throw new ConcurrentModificationException(); 3001 return true; 3002 } 3003 3004 public int characteristics() { 3005 return (side == 0 ? Spliterator.SIZED : 0) | 3006 Spliterator.DISTINCT | Spliterator.SORTED | Spliterator.ORDERED; 3007 } 3008 3009 @Override 3010 public Comparator<Map.Entry<K, V>> getComparator() { 3011 // Adapt or create a key-based comparator 3012 if (tree.comparator != null) { 3013 return Map.Entry.comparingByKey(tree.comparator); 3014 } 3015 else { 3016 return (Comparator<Map.Entry<K, V>> & Serializable) (e1, e2) -> { 3017 @SuppressWarnings("unchecked") 3018 Comparable<? super K> k1 = (Comparable<? super K>) e1.getKey(); 3019 return k1.compareTo(e2.getKey()); 3020 }; 3021 } 3022 } 3023 } 3024} 3025