1 /*
2 * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.util;
27
28 import java.io.Serializable;
29 import java.util.function.BiConsumer;
30 import java.util.function.BiFunction;
31 import java.util.function.Consumer;
32
33 /**
34 * A Red-Black tree based {@link NavigableMap} implementation.
35 * The map is sorted according to the {@linkplain Comparable natural
36 * ordering} of its keys, or by a {@link Comparator} provided at map
37 * creation time, depending on which constructor is used.
38 *
39 * <p>This implementation provides guaranteed log(n) time cost for the
40 * {@code containsKey}, {@code get}, {@code put} and {@code remove}
41 * operations. Algorithms are adaptations of those in Cormen, Leiserson, and
42 * Rivest's <em>Introduction to Algorithms</em>.
43 *
44 * <p>Note that the ordering maintained by a tree map, like any sorted map, and
45 * whether or not an explicit comparator is provided, must be <em>consistent
46 * with {@code equals}</em> if this sorted map is to correctly implement the
47 * {@code Map} interface. (See {@code Comparable} or {@code Comparator} for a
48 * precise definition of <em>consistent with equals</em>.) This is so because
49 * the {@code Map} interface is defined in terms of the {@code equals}
50 * operation, but a sorted map performs all key comparisons using its {@code
51 * compareTo} (or {@code compare}) method, so two keys that are deemed equal by
52 * this method are, from the standpoint of the sorted map, equal. The behavior
53 * of a sorted map <em>is</em> well-defined even if its ordering is
54 * inconsistent with {@code equals}; it just fails to obey the general contract
55 * of the {@code Map} interface.
56 *
57 * <p><strong>Note that this implementation is not synchronized.</strong>
58 * If multiple threads access a map concurrently, and at least one of the
59 * threads modifies the map structurally, it <em>must</em> be synchronized
60 * externally. (A structural modification is any operation that adds or
61 * deletes one or more mappings; merely changing the value associated
62 * with an existing key is not a structural modification.) This is
63 * typically accomplished by synchronizing on some object that naturally
64 * encapsulates the map.
65 * If no such object exists, the map should be "wrapped" using the
66 * {@link Collections#synchronizedSortedMap Collections.synchronizedSortedMap}
67 * method. This is best done at creation time, to prevent accidental
68 * unsynchronized access to the map: <pre>
69 * SortedMap m = Collections.synchronizedSortedMap(new TreeMap(...));</pre>
70 *
71 * <p>The iterators returned by the {@code iterator} method of the collections
72 * returned by all of this class's "collection view methods" are
73 * <em>fail-fast</em>: if the map is structurally modified at any time after
74 * the iterator is created, in any way except through the iterator's own
75 * {@code remove} method, the iterator will throw a {@link
76 * ConcurrentModificationException}. Thus, in the face of concurrent
77 * modification, the iterator fails quickly and cleanly, rather than risking
78 * arbitrary, non-deterministic behavior at an undetermined time in the future.
79 *
80 * <p>Note that the fail-fast behavior of an iterator cannot be guaranteed
81 * as it is, generally speaking, impossible to make any hard guarantees in the
82 * presence of unsynchronized concurrent modification. Fail-fast iterators
83 * throw {@code ConcurrentModificationException} on a best-effort basis.
84 * Therefore, it would be wrong to write a program that depended on this
85 * exception for its correctness: <em>the fail-fast behavior of iterators
86 * should be used only to detect bugs.</em>
87 *
88 * <p>All {@code Map.Entry} pairs returned by methods in this class
89 * and its views represent snapshots of mappings at the time they were
90 * produced. They do <strong>not</strong> support the {@code Entry.setValue}
91 * method. (Note however that it is possible to change mappings in the
92 * associated map using {@code put}.)
93 *
94 * <p>This class is a member of the
95 * <a href="{@docRoot}/java.base/java/util/package-summary.html#CollectionsFramework">
96 * Java Collections Framework</a>.
97 *
98 * @param <K> the type of keys maintained by this map
99 * @param <V> the type of mapped values
100 *
101 * @author Josh Bloch and Doug Lea
102 * @see Map
103 * @see HashMap
104 * @see Hashtable
105 * @see Comparable
106 * @see Comparator
107 * @see Collection
108 * @since 1.2
109 */
110
111 public class TreeMap<K,V>
112 extends AbstractMap<K,V>
113 implements NavigableMap<K,V>, Cloneable, java.io.Serializable
114 {
115 /**
116 * The comparator used to maintain order in this tree map, or
117 * null if it uses the natural ordering of its keys.
118 *
119 * @serial
120 */
121 private final Comparator<? super K> comparator;
122
123 private transient Entry<K,V> root;
124
125 /**
126 * The number of entries in the tree
127 */
128 private transient int size = 0;
129
130 /**
131 * The number of structural modifications to the tree.
132 */
133 private transient int modCount = 0;
134
135 /**
136 * Constructs a new, empty tree map, using the natural ordering of its
137 * keys. All keys inserted into the map must implement the {@link
138 * Comparable} interface. Furthermore, all such keys must be
139 * <em>mutually comparable</em>: {@code k1.compareTo(k2)} must not throw
140 * a {@code ClassCastException} for any keys {@code k1} and
141 * {@code k2} in the map. If the user attempts to put a key into the
142 * map that violates this constraint (for example, the user attempts to
143 * put a string key into a map whose keys are integers), the
144 * {@code put(Object key, Object value)} call will throw a
145 * {@code ClassCastException}.
146 */
147 public TreeMap() {
148 comparator = null;
149 }
150
151 /**
152 * Constructs a new, empty tree map, ordered according to the given
153 * comparator. All keys inserted into the map must be <em>mutually
154 * comparable</em> by the given comparator: {@code comparator.compare(k1,
155 * k2)} must not throw a {@code ClassCastException} for any keys
156 * {@code k1} and {@code k2} in the map. If the user attempts to put
157 * a key into the map that violates this constraint, the {@code put(Object
158 * key, Object value)} call will throw a
159 * {@code ClassCastException}.
160 *
161 * @param comparator the comparator that will be used to order this map.
162 * If {@code null}, the {@linkplain Comparable natural
163 * ordering} of the keys will be used.
164 */
165 public TreeMap(Comparator<? super K> comparator) {
166 this.comparator = comparator;
167 }
168
169 /**
170 * Constructs a new tree map containing the same mappings as the given
171 * map, ordered according to the <em>natural ordering</em> of its keys.
172 * All keys inserted into the new map must implement the {@link
173 * Comparable} interface. Furthermore, all such keys must be
174 * <em>mutually comparable</em>: {@code k1.compareTo(k2)} must not throw
175 * a {@code ClassCastException} for any keys {@code k1} and
176 * {@code k2} in the map. This method runs in n*log(n) time.
177 *
178 * @param m the map whose mappings are to be placed in this map
179 * @throws ClassCastException if the keys in m are not {@link Comparable},
180 * or are not mutually comparable
181 * @throws NullPointerException if the specified map is null
182 */
183 public TreeMap(Map<? extends K, ? extends V> m) {
184 comparator = null;
185 putAll(m);
186 }
187
188 /**
189 * Constructs a new tree map containing the same mappings and
190 * using the same ordering as the specified sorted map. This
191 * method runs in linear time.
192 *
193 * @param m the sorted map whose mappings are to be placed in this map,
194 * and whose comparator is to be used to sort this map
195 * @throws NullPointerException if the specified map is null
196 */
197 public TreeMap(SortedMap<K, ? extends V> m) {
198 comparator = m.comparator();
199 try {
200 buildFromSorted(m.size(), m.entrySet().iterator(), null, null);
201 } catch (java.io.IOException | ClassNotFoundException cannotHappen) {
202 }
203 }
204
205
206 // Query Operations
207
208 /**
209 * Returns the number of key-value mappings in this map.
210 *
211 * @return the number of key-value mappings in this map
212 */
213 public int size() {
214 return size;
215 }
216
217 /**
218 * Returns {@code true} if this map contains a mapping for the specified
219 * key.
220 *
221 * @param key key whose presence in this map is to be tested
222 * @return {@code true} if this map contains a mapping for the
223 * specified key
224 * @throws ClassCastException if the specified key cannot be compared
225 * with the keys currently in the map
226 * @throws NullPointerException if the specified key is null
227 * and this map uses natural ordering, or its comparator
228 * does not permit null keys
229 */
230 public boolean containsKey(Object key) {
231 return getEntry(key) != null;
232 }
233
234 /**
235 * Returns {@code true} if this map maps one or more keys to the
236 * specified value. More formally, returns {@code true} if and only if
237 * this map contains at least one mapping to a value {@code v} such
238 * that {@code (value==null ? v==null : value.equals(v))}. This
239 * operation will probably require time linear in the map size for
240 * most implementations.
241 *
242 * @param value value whose presence in this map is to be tested
243 * @return {@code true} if a mapping to {@code value} exists;
244 * {@code false} otherwise
245 * @since 1.2
246 */
247 public boolean containsValue(Object value) {
248 for (Entry<K,V> e = getFirstEntry(); e != null; e = successor(e))
249 if (valEquals(value, e.value))
250 return true;
251 return false;
252 }
253
254 /**
255 * Returns the value to which the specified key is mapped,
256 * or {@code null} if this map contains no mapping for the key.
257 *
258 * <p>More formally, if this map contains a mapping from a key
259 * {@code k} to a value {@code v} such that {@code key} compares
260 * equal to {@code k} according to the map's ordering, then this
261 * method returns {@code v}; otherwise it returns {@code null}.
262 * (There can be at most one such mapping.)
263 *
264 * <p>A return value of {@code null} does not <em>necessarily</em>
265 * indicate that the map contains no mapping for the key; it's also
266 * possible that the map explicitly maps the key to {@code null}.
267 * The {@link #containsKey containsKey} operation may be used to
268 * distinguish these two cases.
269 *
270 * @throws ClassCastException if the specified key cannot be compared
271 * with the keys currently in the map
272 * @throws NullPointerException if the specified key is null
273 * and this map uses natural ordering, or its comparator
274 * does not permit null keys
275 */
276 public V get(Object key) {
277 Entry<K,V> p = getEntry(key);
278 return (p==null ? null : p.value);
279 }
280
281 public Comparator<? super K> comparator() {
282 return comparator;
283 }
284
285 /**
286 * @throws NoSuchElementException {@inheritDoc}
287 */
288 public K firstKey() {
289 return key(getFirstEntry());
290 }
291
292 /**
293 * @throws NoSuchElementException {@inheritDoc}
294 */
295 public K lastKey() {
296 return key(getLastEntry());
297 }
298
299 /**
300 * Copies all of the mappings from the specified map to this map.
301 * These mappings replace any mappings that this map had for any
302 * of the keys currently in the specified map.
303 *
304 * @param map mappings to be stored in this map
305 * @throws ClassCastException if the class of a key or value in
306 * the specified map prevents it from being stored in this map
307 * @throws NullPointerException if the specified map is null or
308 * the specified map contains a null key and this map does not
309 * permit null keys
310 */
311 public void putAll(Map<? extends K, ? extends V> map) {
312 int mapSize = map.size();
313 if (size==0 && mapSize!=0 && map instanceof SortedMap) {
314 Comparator<?> c = ((SortedMap<?,?>)map).comparator();
315 if (c == comparator || (c != null && c.equals(comparator))) {
316 ++modCount;
317 try {
318 buildFromSorted(mapSize, map.entrySet().iterator(),
319 null, null);
320 } catch (java.io.IOException | ClassNotFoundException cannotHappen) {
321 }
322 return;
323 }
324 }
325 super.putAll(map);
326 }
327
328 /**
329 * Returns this map's entry for the given key, or {@code null} if the map
330 * does not contain an entry for the key.
331 *
332 * @return this map's entry for the given key, or {@code null} if the map
333 * does not contain an entry for the key
334 * @throws ClassCastException if the specified key cannot be compared
335 * with the keys currently in the map
336 * @throws NullPointerException if the specified key is null
337 * and this map uses natural ordering, or its comparator
338 * does not permit null keys
339 */
340 final Entry<K,V> getEntry(Object key) {
341 // Offload comparator-based version for sake of performance
342 if (comparator != null)
343 return getEntryUsingComparator(key);
344 if (key == null)
345 throw new NullPointerException();
346 @SuppressWarnings("unchecked")
347 Comparable<? super K> k = (Comparable<? super K>) key;
348 Entry<K,V> p = root;
349 while (p != null) {
350 int cmp = k.compareTo(p.key);
351 if (cmp < 0)
352 p = p.left;
353 else if (cmp > 0)
354 p = p.right;
355 else
356 return p;
357 }
358 return null;
359 }
360
361 /**
362 * Version of getEntry using comparator. Split off from getEntry
363 * for performance. (This is not worth doing for most methods,
364 * that are less dependent on comparator performance, but is
365 * worthwhile here.)
366 */
367 final Entry<K,V> getEntryUsingComparator(Object key) {
368 @SuppressWarnings("unchecked")
369 K k = (K) key;
370 Comparator<? super K> cpr = comparator;
371 if (cpr != null) {
372 Entry<K,V> p = root;
373 while (p != null) {
374 int cmp = cpr.compare(k, p.key);
375 if (cmp < 0)
376 p = p.left;
377 else if (cmp > 0)
378 p = p.right;
379 else
380 return p;
381 }
382 }
383 return null;
384 }
385
386 /**
387 * Gets the entry corresponding to the specified key; if no such entry
388 * exists, returns the entry for the least key greater than the specified
389 * key; if no such entry exists (i.e., the greatest key in the Tree is less
390 * than the specified key), returns {@code null}.
391 */
392 final Entry<K,V> getCeilingEntry(K key) {
393 Entry<K,V> p = root;
394 while (p != null) {
395 int cmp = compare(key, p.key);
396 if (cmp < 0) {
397 if (p.left != null)
398 p = p.left;
399 else
400 return p;
401 } else if (cmp > 0) {
402 if (p.right != null) {
403 p = p.right;
404 } else {
405 Entry<K,V> parent = p.parent;
406 Entry<K,V> ch = p;
407 while (parent != null && ch == parent.right) {
408 ch = parent;
409 parent = parent.parent;
410 }
411 return parent;
412 }
413 } else
414 return p;
415 }
416 return null;
417 }
418
419 /**
420 * Gets the entry corresponding to the specified key; if no such entry
421 * exists, returns the entry for the greatest key less than the specified
422 * key; if no such entry exists, returns {@code null}.
423 */
424 final Entry<K,V> getFloorEntry(K key) {
425 Entry<K,V> p = root;
426 while (p != null) {
427 int cmp = compare(key, p.key);
428 if (cmp > 0) {
429 if (p.right != null)
430 p = p.right;
431 else
432 return p;
433 } else if (cmp < 0) {
434 if (p.left != null) {
435 p = p.left;
436 } else {
437 Entry<K,V> parent = p.parent;
438 Entry<K,V> ch = p;
439 while (parent != null && ch == parent.left) {
440 ch = parent;
441 parent = parent.parent;
442 }
443 return parent;
444 }
445 } else
446 return p;
447
448 }
449 return null;
450 }
451
452 /**
453 * Gets the entry for the least key greater than the specified
454 * key; if no such entry exists, returns the entry for the least
455 * key greater than the specified key; if no such entry exists
456 * returns {@code null}.
457 */
458 final Entry<K,V> getHigherEntry(K key) {
459 Entry<K,V> p = root;
460 while (p != null) {
461 int cmp = compare(key, p.key);
462 if (cmp < 0) {
463 if (p.left != null)
464 p = p.left;
465 else
466 return p;
467 } else {
468 if (p.right != null) {
469 p = p.right;
470 } else {
471 Entry<K,V> parent = p.parent;
472 Entry<K,V> ch = p;
473 while (parent != null && ch == parent.right) {
474 ch = parent;
475 parent = parent.parent;
476 }
477 return parent;
478 }
479 }
480 }
481 return null;
482 }
483
484 /**
485 * Returns the entry for the greatest key less than the specified key; if
486 * no such entry exists (i.e., the least key in the Tree is greater than
487 * the specified key), returns {@code null}.
488 */
489 final Entry<K,V> getLowerEntry(K key) {
490 Entry<K,V> p = root;
491 while (p != null) {
492 int cmp = compare(key, p.key);
493 if (cmp > 0) {
494 if (p.right != null)
495 p = p.right;
496 else
497 return p;
498 } else {
499 if (p.left != null) {
500 p = p.left;
501 } else {
502 Entry<K,V> parent = p.parent;
503 Entry<K,V> ch = p;
504 while (parent != null && ch == parent.left) {
505 ch = parent;
506 parent = parent.parent;
507 }
508 return parent;
509 }
510 }
511 }
512 return null;
513 }
514
515 /**
516 * Associates the specified value with the specified key in this map.
517 * If the map previously contained a mapping for the key, the old
518 * value is replaced.
519 *
520 * @param key key with which the specified value is to be associated
521 * @param value value to be associated with the specified key
522 *
523 * @return the previous value associated with {@code key}, or
524 * {@code null} if there was no mapping for {@code key}.
525 * (A {@code null} return can also indicate that the map
526 * previously associated {@code null} with {@code key}.)
527 * @throws ClassCastException if the specified key cannot be compared
528 * with the keys currently in the map
529 * @throws NullPointerException if the specified key is null
530 * and this map uses natural ordering, or its comparator
531 * does not permit null keys
532 */
533 public V put(K key, V value) {
534 Entry<K,V> t = root;
535 if (t == null) {
536 compare(key, key); // type (and possibly null) check
537
538 root = new Entry<>(key, value, null);
539 size = 1;
540 modCount++;
541 return null;
542 }
543 int cmp;
544 Entry<K,V> parent;
545 // split comparator and comparable paths
546 Comparator<? super K> cpr = comparator;
547 if (cpr != null) {
548 do {
549 parent = t;
550 cmp = cpr.compare(key, t.key);
551 if (cmp < 0)
552 t = t.left;
553 else if (cmp > 0)
554 t = t.right;
555 else
556 return t.setValue(value);
557 } while (t != null);
558 }
559 else {
560 if (key == null)
561 throw new NullPointerException();
562 @SuppressWarnings("unchecked")
563 Comparable<? super K> k = (Comparable<? super K>) key;
564 do {
565 parent = t;
566 cmp = k.compareTo(t.key);
567 if (cmp < 0)
568 t = t.left;
569 else if (cmp > 0)
570 t = t.right;
571 else
572 return t.setValue(value);
573 } while (t != null);
574 }
575 Entry<K,V> e = new Entry<>(key, value, parent);
576 if (cmp < 0)
577 parent.left = e;
578 else
579 parent.right = e;
580 fixAfterInsertion(e);
581 size++;
582 modCount++;
583 return null;
584 }
585
586 /**
587 * Removes the mapping for this key from this TreeMap if present.
588 *
589 * @param key key for which mapping should be removed
590 * @return the previous value associated with {@code key}, or
591 * {@code null} if there was no mapping for {@code key}.
592 * (A {@code null} return can also indicate that the map
593 * previously associated {@code null} with {@code key}.)
594 * @throws ClassCastException if the specified key cannot be compared
595 * with the keys currently in the map
596 * @throws NullPointerException if the specified key is null
597 * and this map uses natural ordering, or its comparator
598 * does not permit null keys
599 */
600 public V remove(Object key) {
601 Entry<K,V> p = getEntry(key);
602 if (p == null)
603 return null;
604
605 V oldValue = p.value;
606 deleteEntry(p);
607 return oldValue;
608 }
609
610 /**
611 * Removes all of the mappings from this map.
612 * The map will be empty after this call returns.
613 */
614 public void clear() {
615 modCount++;
616 size = 0;
617 root = null;
618 }
619
620 /**
621 * Returns a shallow copy of this {@code TreeMap} instance. (The keys and
622 * values themselves are not cloned.)
623 *
624 * @return a shallow copy of this map
625 */
626 public Object clone() {
627 TreeMap<?,?> clone;
628 try {
629 clone = (TreeMap<?,?>) super.clone();
630 } catch (CloneNotSupportedException e) {
631 throw new InternalError(e);
632 }
633
634 // Put clone into "virgin" state (except for comparator)
635 clone.root = null;
636 clone.size = 0;
637 clone.modCount = 0;
638 clone.entrySet = null;
639 clone.navigableKeySet = null;
640 clone.descendingMap = null;
641
642 // Initialize clone with our mappings
643 try {
644 clone.buildFromSorted(size, entrySet().iterator(), null, null);
645 } catch (java.io.IOException | ClassNotFoundException cannotHappen) {
646 }
647
648 return clone;
649 }
650
651 // NavigableMap API methods
652
653 /**
654 * @since 1.6
655 */
656 public Map.Entry<K,V> firstEntry() {
657 return exportEntry(getFirstEntry());
658 }
659
660 /**
661 * @since 1.6
662 */
663 public Map.Entry<K,V> lastEntry() {
664 return exportEntry(getLastEntry());
665 }
666
667 /**
668 * @since 1.6
669 */
670 public Map.Entry<K,V> pollFirstEntry() {
671 Entry<K,V> p = getFirstEntry();
672 Map.Entry<K,V> result = exportEntry(p);
673 if (p != null)
674 deleteEntry(p);
675 return result;
676 }
677
678 /**
679 * @since 1.6
680 */
681 public Map.Entry<K,V> pollLastEntry() {
682 Entry<K,V> p = getLastEntry();
683 Map.Entry<K,V> result = exportEntry(p);
684 if (p != null)
685 deleteEntry(p);
686 return result;
687 }
688
689 /**
690 * @throws ClassCastException {@inheritDoc}
691 * @throws NullPointerException if the specified key is null
692 * and this map uses natural ordering, or its comparator
693 * does not permit null keys
694 * @since 1.6
695 */
696 public Map.Entry<K,V> lowerEntry(K key) {
697 return exportEntry(getLowerEntry(key));
698 }
699
700 /**
701 * @throws ClassCastException {@inheritDoc}
702 * @throws NullPointerException if the specified key is null
703 * and this map uses natural ordering, or its comparator
704 * does not permit null keys
705 * @since 1.6
706 */
707 public K lowerKey(K key) {
708 return keyOrNull(getLowerEntry(key));
709 }
710
711 /**
712 * @throws ClassCastException {@inheritDoc}
713 * @throws NullPointerException if the specified key is null
714 * and this map uses natural ordering, or its comparator
715 * does not permit null keys
716 * @since 1.6
717 */
718 public Map.Entry<K,V> floorEntry(K key) {
719 return exportEntry(getFloorEntry(key));
720 }
721
722 /**
723 * @throws ClassCastException {@inheritDoc}
724 * @throws NullPointerException if the specified key is null
725 * and this map uses natural ordering, or its comparator
726 * does not permit null keys
727 * @since 1.6
728 */
729 public K floorKey(K key) {
730 return keyOrNull(getFloorEntry(key));
731 }
732
733 /**
734 * @throws ClassCastException {@inheritDoc}
735 * @throws NullPointerException if the specified key is null
736 * and this map uses natural ordering, or its comparator
737 * does not permit null keys
738 * @since 1.6
739 */
740 public Map.Entry<K,V> ceilingEntry(K key) {
741 return exportEntry(getCeilingEntry(key));
742 }
743
744 /**
745 * @throws ClassCastException {@inheritDoc}
746 * @throws NullPointerException if the specified key is null
747 * and this map uses natural ordering, or its comparator
748 * does not permit null keys
749 * @since 1.6
750 */
751 public K ceilingKey(K key) {
752 return keyOrNull(getCeilingEntry(key));
753 }
754
755 /**
756 * @throws ClassCastException {@inheritDoc}
757 * @throws NullPointerException if the specified key is null
758 * and this map uses natural ordering, or its comparator
759 * does not permit null keys
760 * @since 1.6
761 */
762 public Map.Entry<K,V> higherEntry(K key) {
763 return exportEntry(getHigherEntry(key));
764 }
765
766 /**
767 * @throws ClassCastException {@inheritDoc}
768 * @throws NullPointerException if the specified key is null
769 * and this map uses natural ordering, or its comparator
770 * does not permit null keys
771 * @since 1.6
772 */
773 public K higherKey(K key) {
774 return keyOrNull(getHigherEntry(key));
775 }
776
777 // Views
778
779 /**
780 * Fields initialized to contain an instance of the entry set view
781 * the first time this view is requested. Views are stateless, so
782 * there's no reason to create more than one.
783 */
784 private transient EntrySet entrySet;
785 private transient KeySet<K> navigableKeySet;
786 private transient NavigableMap<K,V> descendingMap;
787
788 /**
789 * Returns a {@link Set} view of the keys contained in this map.
790 *
791 * <p>The set's iterator returns the keys in ascending order.
792 * The set's spliterator is
793 * <em><a href="Spliterator.html#binding">late-binding</a></em>,
794 * <em>fail-fast</em>, and additionally reports {@link Spliterator#SORTED}
795 * and {@link Spliterator#ORDERED} with an encounter order that is ascending
796 * key order. The spliterator's comparator (see
797 * {@link java.util.Spliterator#getComparator()}) is {@code null} if
798 * the tree map's comparator (see {@link #comparator()}) is {@code null}.
799 * Otherwise, the spliterator's comparator is the same as or imposes the
800 * same total ordering as the tree map's comparator.
801 *
802 * <p>The set is backed by the map, so changes to the map are
803 * reflected in the set, and vice-versa. If the map is modified
804 * while an iteration over the set is in progress (except through
805 * the iterator's own {@code remove} operation), the results of
806 * the iteration are undefined. The set supports element removal,
807 * which removes the corresponding mapping from the map, via the
808 * {@code Iterator.remove}, {@code Set.remove},
809 * {@code removeAll}, {@code retainAll}, and {@code clear}
810 * operations. It does not support the {@code add} or {@code addAll}
811 * operations.
812 */
813 public Set<K> keySet() {
814 return navigableKeySet();
815 }
816
817 /**
818 * @since 1.6
819 */
820 public NavigableSet<K> navigableKeySet() {
821 KeySet<K> nks = navigableKeySet;
822 return (nks != null) ? nks : (navigableKeySet = new KeySet<>(this));
823 }
824
825 /**
826 * @since 1.6
827 */
828 public NavigableSet<K> descendingKeySet() {
829 return descendingMap().navigableKeySet();
830 }
831
832 /**
833 * Returns a {@link Collection} view of the values contained in this map.
834 *
835 * <p>The collection's iterator returns the values in ascending order
836 * of the corresponding keys. The collection's spliterator is
837 * <em><a href="Spliterator.html#binding">late-binding</a></em>,
838 * <em>fail-fast</em>, and additionally reports {@link Spliterator#ORDERED}
839 * with an encounter order that is ascending order of the corresponding
840 * keys.
841 *
842 * <p>The collection is backed by the map, so changes to the map are
843 * reflected in the collection, and vice-versa. If the map is
844 * modified while an iteration over the collection is in progress
845 * (except through the iterator's own {@code remove} operation),
846 * the results of the iteration are undefined. The collection
847 * supports element removal, which removes the corresponding
848 * mapping from the map, via the {@code Iterator.remove},
849 * {@code Collection.remove}, {@code removeAll},
850 * {@code retainAll} and {@code clear} operations. It does not
851 * support the {@code add} or {@code addAll} operations.
852 */
853 public Collection<V> values() {
854 Collection<V> vs = values;
855 if (vs == null) {
856 vs = new Values();
857 values = vs;
858 }
859 return vs;
860 }
861
862 /**
863 * Returns a {@link Set} view of the mappings contained in this map.
864 *
865 * <p>The set's iterator returns the entries in ascending key order. The
866 * set's spliterator is
867 * <em><a href="Spliterator.html#binding">late-binding</a></em>,
868 * <em>fail-fast</em>, and additionally reports {@link Spliterator#SORTED} and
869 * {@link Spliterator#ORDERED} with an encounter order that is ascending key
870 * order.
871 *
872 * <p>The set is backed by the map, so changes to the map are
873 * reflected in the set, and vice-versa. If the map is modified
874 * while an iteration over the set is in progress (except through
875 * the iterator's own {@code remove} operation, or through the
876 * {@code setValue} operation on a map entry returned by the
877 * iterator) the results of the iteration are undefined. The set
878 * supports element removal, which removes the corresponding
879 * mapping from the map, via the {@code Iterator.remove},
880 * {@code Set.remove}, {@code removeAll}, {@code retainAll} and
881 * {@code clear} operations. It does not support the
882 * {@code add} or {@code addAll} operations.
883 */
884 public Set<Map.Entry<K,V>> entrySet() {
885 EntrySet es = entrySet;
886 return (es != null) ? es : (entrySet = new EntrySet());
887 }
888
889 /**
890 * @since 1.6
891 */
892 public NavigableMap<K, V> descendingMap() {
893 NavigableMap<K, V> km = descendingMap;
894 return (km != null) ? km :
895 (descendingMap = new DescendingSubMap<>(this,
896 true, null, true,
897 true, null, true));
898 }
899
900 /**
901 * @throws ClassCastException {@inheritDoc}
902 * @throws NullPointerException if {@code fromKey} or {@code toKey} is
903 * null and this map uses natural ordering, or its comparator
904 * does not permit null keys
905 * @throws IllegalArgumentException {@inheritDoc}
906 * @since 1.6
907 */
908 public NavigableMap<K,V> subMap(K fromKey, boolean fromInclusive,
909 K toKey, boolean toInclusive) {
910 return new AscendingSubMap<>(this,
911 false, fromKey, fromInclusive,
912 false, toKey, toInclusive);
913 }
914
915 /**
916 * @throws ClassCastException {@inheritDoc}
917 * @throws NullPointerException if {@code toKey} is null
918 * and this map uses natural ordering, or its comparator
919 * does not permit null keys
920 * @throws IllegalArgumentException {@inheritDoc}
921 * @since 1.6
922 */
923 public NavigableMap<K,V> headMap(K toKey, boolean inclusive) {
924 return new AscendingSubMap<>(this,
925 true, null, true,
926 false, toKey, inclusive);
927 }
928
929 /**
930 * @throws ClassCastException {@inheritDoc}
931 * @throws NullPointerException if {@code fromKey} is null
932 * and this map uses natural ordering, or its comparator
933 * does not permit null keys
934 * @throws IllegalArgumentException {@inheritDoc}
935 * @since 1.6
936 */
937 public NavigableMap<K,V> tailMap(K fromKey, boolean inclusive) {
938 return new AscendingSubMap<>(this,
939 false, fromKey, inclusive,
940 true, null, true);
941 }
942
943 /**
944 * @throws ClassCastException {@inheritDoc}
945 * @throws NullPointerException if {@code fromKey} or {@code toKey} is
946 * null and this map uses natural ordering, or its comparator
947 * does not permit null keys
948 * @throws IllegalArgumentException {@inheritDoc}
949 */
950 public SortedMap<K,V> subMap(K fromKey, K toKey) {
951 return subMap(fromKey, true, toKey, false);
952 }
953
954 /**
955 * @throws ClassCastException {@inheritDoc}
956 * @throws NullPointerException if {@code toKey} is null
957 * and this map uses natural ordering, or its comparator
958 * does not permit null keys
959 * @throws IllegalArgumentException {@inheritDoc}
960 */
961 public SortedMap<K,V> headMap(K toKey) {
962 return headMap(toKey, false);
963 }
964
965 /**
966 * @throws ClassCastException {@inheritDoc}
967 * @throws NullPointerException if {@code fromKey} is null
968 * and this map uses natural ordering, or its comparator
969 * does not permit null keys
970 * @throws IllegalArgumentException {@inheritDoc}
971 */
972 public SortedMap<K,V> tailMap(K fromKey) {
973 return tailMap(fromKey, true);
974 }
975
976 @Override
977 public boolean replace(K key, V oldValue, V newValue) {
978 Entry<K,V> p = getEntry(key);
979 if (p!=null && Objects.equals(oldValue, p.value)) {
980 p.value = newValue;
981 return true;
982 }
983 return false;
984 }
985
986 @Override
987 public V replace(K key, V value) {
988 Entry<K,V> p = getEntry(key);
989 if (p!=null) {
990 V oldValue = p.value;
991 p.value = value;
992 return oldValue;
993 }
994 return null;
995 }
996
997 @Override
998 public void forEach(BiConsumer<? super K, ? super V> action) {
999 Objects.requireNonNull(action);
1000 int expectedModCount = modCount;
1001 for (Entry<K, V> e = getFirstEntry(); e != null; e = successor(e)) {
1002 action.accept(e.key, e.value);
1003
1004 if (expectedModCount != modCount) {
1005 throw new ConcurrentModificationException();
1006 }
1007 }
1008 }
1009
1010 @Override
1011 public void replaceAll(BiFunction<? super K, ? super V, ? extends V> function) {
1012 Objects.requireNonNull(function);
1013 int expectedModCount = modCount;
1014
1015 for (Entry<K, V> e = getFirstEntry(); e != null; e = successor(e)) {
1016 e.value = function.apply(e.key, e.value);
1017
1018 if (expectedModCount != modCount) {
1019 throw new ConcurrentModificationException();
1020 }
1021 }
1022 }
1023
1024 // View class support
1025
1026 class Values extends AbstractCollection<V> {
1027 public Iterator<V> iterator() {
1028 return new ValueIterator(getFirstEntry());
1029 }
1030
1031 public int size() {
1032 return TreeMap.this.size();
1033 }
1034
1035 public boolean contains(Object o) {
1036 return TreeMap.this.containsValue(o);
1037 }
1038
1039 public boolean remove(Object o) {
1040 for (Entry<K,V> e = getFirstEntry(); e != null; e = successor(e)) {
1041 if (valEquals(e.getValue(), o)) {
1042 deleteEntry(e);
1043 return true;
1044 }
1045 }
1046 return false;
1047 }
1048
1049 public void clear() {
1050 TreeMap.this.clear();
1051 }
1052
1053 public Spliterator<V> spliterator() {
1054 return new ValueSpliterator<>(TreeMap.this, null, null, 0, -1, 0);
1055 }
1056 }
1057
1058 class EntrySet extends AbstractSet<Map.Entry<K,V>> {
1059 public Iterator<Map.Entry<K,V>> iterator() {
1060 return new EntryIterator(getFirstEntry());
1061 }
1062
1063 public boolean contains(Object o) {
1064 if (!(o instanceof Map.Entry))
1065 return false;
1066 Map.Entry<?,?> entry = (Map.Entry<?,?>) o;
1067 Object value = entry.getValue();
1068 Entry<K,V> p = getEntry(entry.getKey());
1069 return p != null && valEquals(p.getValue(), value);
1070 }
1071
1072 public boolean remove(Object o) {
1073 if (!(o instanceof Map.Entry))
1074 return false;
1075 Map.Entry<?,?> entry = (Map.Entry<?,?>) o;
1076 Object value = entry.getValue();
1077 Entry<K,V> p = getEntry(entry.getKey());
1078 if (p != null && valEquals(p.getValue(), value)) {
1079 deleteEntry(p);
1080 return true;
1081 }
1082 return false;
1083 }
1084
1085 public int size() {
1086 return TreeMap.this.size();
1087 }
1088
1089 public void clear() {
1090 TreeMap.this.clear();
1091 }
1092
1093 public Spliterator<Map.Entry<K,V>> spliterator() {
1094 return new EntrySpliterator<>(TreeMap.this, null, null, 0, -1, 0);
1095 }
1096 }
1097
1098 /*
1099 * Unlike Values and EntrySet, the KeySet class is static,
1100 * delegating to a NavigableMap to allow use by SubMaps, which
1101 * outweighs the ugliness of needing type-tests for the following
1102 * Iterator methods that are defined appropriately in main versus
1103 * submap classes.
1104 */
1105
1106 Iterator<K> keyIterator() {
1107 return new KeyIterator(getFirstEntry());
1108 }
1109
1110 Iterator<K> descendingKeyIterator() {
1111 return new DescendingKeyIterator(getLastEntry());
1112 }
1113
1114 static final class KeySet<E> extends AbstractSet<E> implements NavigableSet<E> {
1115 private final NavigableMap<E, ?> m;
1116 KeySet(NavigableMap<E,?> map) { m = map; }
1117
1118 public Iterator<E> iterator() {
1119 if (m instanceof TreeMap)
1120 return ((TreeMap<E,?>)m).keyIterator();
1121 else
1122 return ((TreeMap.NavigableSubMap<E,?>)m).keyIterator();
1123 }
1124
1125 public Iterator<E> descendingIterator() {
1126 if (m instanceof TreeMap)
1127 return ((TreeMap<E,?>)m).descendingKeyIterator();
1128 else
1129 return ((TreeMap.NavigableSubMap<E,?>)m).descendingKeyIterator();
1130 }
1131
1132 public int size() { return m.size(); }
1133 public boolean isEmpty() { return m.isEmpty(); }
1134 public boolean contains(Object o) { return m.containsKey(o); }
1135 public void clear() { m.clear(); }
1136 public E lower(E e) { return m.lowerKey(e); }
1137 public E floor(E e) { return m.floorKey(e); }
1138 public E ceiling(E e) { return m.ceilingKey(e); }
1139 public E higher(E e) { return m.higherKey(e); }
1140 public E first() { return m.firstKey(); }
1141 public E last() { return m.lastKey(); }
1142 public Comparator<? super E> comparator() { return m.comparator(); }
1143 public E pollFirst() {
1144 Map.Entry<E,?> e = m.pollFirstEntry();
1145 return (e == null) ? null : e.getKey();
1146 }
1147 public E pollLast() {
1148 Map.Entry<E,?> e = m.pollLastEntry();
1149 return (e == null) ? null : e.getKey();
1150 }
1151 public boolean remove(Object o) {
1152 int oldSize = size();
1153 m.remove(o);
1154 return size() != oldSize;
1155 }
1156 public NavigableSet<E> subSet(E fromElement, boolean fromInclusive,
1157 E toElement, boolean toInclusive) {
1158 return new KeySet<>(m.subMap(fromElement, fromInclusive,
1159 toElement, toInclusive));
1160 }
1161 public NavigableSet<E> headSet(E toElement, boolean inclusive) {
1162 return new KeySet<>(m.headMap(toElement, inclusive));
1163 }
1164 public NavigableSet<E> tailSet(E fromElement, boolean inclusive) {
1165 return new KeySet<>(m.tailMap(fromElement, inclusive));
1166 }
1167 public SortedSet<E> subSet(E fromElement, E toElement) {
1168 return subSet(fromElement, true, toElement, false);
1169 }
1170 public SortedSet<E> headSet(E toElement) {
1171 return headSet(toElement, false);
1172 }
1173 public SortedSet<E> tailSet(E fromElement) {
1174 return tailSet(fromElement, true);
1175 }
1176 public NavigableSet<E> descendingSet() {
1177 return new KeySet<>(m.descendingMap());
1178 }
1179
1180 public Spliterator<E> spliterator() {
1181 return keySpliteratorFor(m);
1182 }
1183 }
1184
1185 /**
1186 * Base class for TreeMap Iterators
1187 */
1188 abstract class PrivateEntryIterator<T> implements Iterator<T> {
1189 Entry<K,V> next;
1190 Entry<K,V> lastReturned;
1191 int expectedModCount;
1192
1193 PrivateEntryIterator(Entry<K,V> first) {
1194 expectedModCount = modCount;
1195 lastReturned = null;
1196 next = first;
1197 }
1198
1199 public final boolean hasNext() {
1200 return next != null;
1201 }
1202
1203 final Entry<K,V> nextEntry() {
1204 Entry<K,V> e = next;
1205 if (e == null)
1206 throw new NoSuchElementException();
1207 if (modCount != expectedModCount)
1208 throw new ConcurrentModificationException();
1209 next = successor(e);
1210 lastReturned = e;
1211 return e;
1212 }
1213
1214 final Entry<K,V> prevEntry() {
1215 Entry<K,V> e = next;
1216 if (e == null)
1217 throw new NoSuchElementException();
1218 if (modCount != expectedModCount)
1219 throw new ConcurrentModificationException();
1220 next = predecessor(e);
1221 lastReturned = e;
1222 return e;
1223 }
1224
1225 public void remove() {
1226 if (lastReturned == null)
1227 throw new IllegalStateException();
1228 if (modCount != expectedModCount)
1229 throw new ConcurrentModificationException();
1230 // deleted entries are replaced by their successors
1231 if (lastReturned.left != null && lastReturned.right != null)
1232 next = lastReturned;
1233 deleteEntry(lastReturned);
1234 expectedModCount = modCount;
1235 lastReturned = null;
1236 }
1237 }
1238
1239 final class EntryIterator extends PrivateEntryIterator<Map.Entry<K,V>> {
1240 EntryIterator(Entry<K,V> first) {
1241 super(first);
1242 }
1243 public Map.Entry<K,V> next() {
1244 return nextEntry();
1245 }
1246 }
1247
1248 final class ValueIterator extends PrivateEntryIterator<V> {
1249 ValueIterator(Entry<K,V> first) {
1250 super(first);
1251 }
1252 public V next() {
1253 return nextEntry().value;
1254 }
1255 }
1256
1257 final class KeyIterator extends PrivateEntryIterator<K> {
1258 KeyIterator(Entry<K,V> first) {
1259 super(first);
1260 }
1261 public K next() {
1262 return nextEntry().key;
1263 }
1264 }
1265
1266 final class DescendingKeyIterator extends PrivateEntryIterator<K> {
1267 DescendingKeyIterator(Entry<K,V> first) {
1268 super(first);
1269 }
1270 public K next() {
1271 return prevEntry().key;
1272 }
1273 public void remove() {
1274 if (lastReturned == null)
1275 throw new IllegalStateException();
1276 if (modCount != expectedModCount)
1277 throw new ConcurrentModificationException();
1278 deleteEntry(lastReturned);
1279 lastReturned = null;
1280 expectedModCount = modCount;
1281 }
1282 }
1283
1284 // Little utilities
1285
1286 /**
1287 * Compares two keys using the correct comparison method for this TreeMap.
1288 */
1289 @SuppressWarnings("unchecked")
1290 final int compare(Object k1, Object k2) {
1291 return comparator==null ? ((Comparable<? super K>)k1).compareTo((K)k2)
1292 : comparator.compare((K)k1, (K)k2);
1293 }
1294
1295 /**
1296 * Test two values for equality. Differs from o1.equals(o2) only in
1297 * that it copes with {@code null} o1 properly.
1298 */
1299 static final boolean valEquals(Object o1, Object o2) {
1300 return (o1==null ? o2==null : o1.equals(o2));
1301 }
1302
1303 /**
1304 * Return SimpleImmutableEntry for entry, or null if null
1305 */
1306 static <K,V> Map.Entry<K,V> exportEntry(TreeMap.Entry<K,V> e) {
1307 return (e == null) ? null :
1308 new AbstractMap.SimpleImmutableEntry<>(e);
1309 }
1310
1311 /**
1312 * Return key for entry, or null if null
1313 */
1314 static <K,V> K keyOrNull(TreeMap.Entry<K,V> e) {
1315 return (e == null) ? null : e.key;
1316 }
1317
1318 /**
1319 * Returns the key corresponding to the specified Entry.
1320 * @throws NoSuchElementException if the Entry is null
1321 */
1322 static <K> K key(Entry<K,?> e) {
1323 if (e==null)
1324 throw new NoSuchElementException();
1325 return e.key;
1326 }
1327
1328
1329 // SubMaps
1330
1331 /**
1332 * Dummy value serving as unmatchable fence key for unbounded
1333 * SubMapIterators
1334 */
1335 private static final Object UNBOUNDED = new Object();
1336
1337 /**
1338 * @serial include
1339 */
1340 abstract static class NavigableSubMap<K,V> extends AbstractMap<K,V>
1341 implements NavigableMap<K,V>, java.io.Serializable {
1342 @java.io.Serial
1343 private static final long serialVersionUID = -2102997345730753016L;
1344 /**
1345 * The backing map.
1346 */
1347 final TreeMap<K,V> m;
1348
1349 /**
1350 * Endpoints are represented as triples (fromStart, lo,
1351 * loInclusive) and (toEnd, hi, hiInclusive). If fromStart is
1352 * true, then the low (absolute) bound is the start of the
1353 * backing map, and the other values are ignored. Otherwise,
1354 * if loInclusive is true, lo is the inclusive bound, else lo
1355 * is the exclusive bound. Similarly for the upper bound.
1356 */
1357 final K lo, hi;
1358 final boolean fromStart, toEnd;
1359 final boolean loInclusive, hiInclusive;
1360
1361 NavigableSubMap(TreeMap<K,V> m,
1362 boolean fromStart, K lo, boolean loInclusive,
1363 boolean toEnd, K hi, boolean hiInclusive) {
1364 if (!fromStart && !toEnd) {
1365 if (m.compare(lo, hi) > 0)
1366 throw new IllegalArgumentException("fromKey > toKey");
1367 } else {
1368 if (!fromStart) // type check
1369 m.compare(lo, lo);
1370 if (!toEnd)
1371 m.compare(hi, hi);
1372 }
1373
1374 this.m = m;
1375 this.fromStart = fromStart;
1376 this.lo = lo;
1377 this.loInclusive = loInclusive;
1378 this.toEnd = toEnd;
1379 this.hi = hi;
1380 this.hiInclusive = hiInclusive;
1381 }
1382
1383 // internal utilities
1384
1385 final boolean tooLow(Object key) {
1386 if (!fromStart) {
1387 int c = m.compare(key, lo);
1388 if (c < 0 || (c == 0 && !loInclusive))
1389 return true;
1390 }
1391 return false;
1392 }
1393
1394 final boolean tooHigh(Object key) {
1395 if (!toEnd) {
1396 int c = m.compare(key, hi);
1397 if (c > 0 || (c == 0 && !hiInclusive))
1398 return true;
1399 }
1400 return false;
1401 }
1402
1403 final boolean inRange(Object key) {
1404 return !tooLow(key) && !tooHigh(key);
1405 }
1406
1407 final boolean inClosedRange(Object key) {
1408 return (fromStart || m.compare(key, lo) >= 0)
1409 && (toEnd || m.compare(hi, key) >= 0);
1410 }
1411
1412 final boolean inRange(Object key, boolean inclusive) {
1413 return inclusive ? inRange(key) : inClosedRange(key);
1414 }
1415
1416 /*
1417 * Absolute versions of relation operations.
1418 * Subclasses map to these using like-named "sub"
1419 * versions that invert senses for descending maps
1420 */
1421
1422 final TreeMap.Entry<K,V> absLowest() {
1423 TreeMap.Entry<K,V> e =
1424 (fromStart ? m.getFirstEntry() :
1425 (loInclusive ? m.getCeilingEntry(lo) :
1426 m.getHigherEntry(lo)));
1427 return (e == null || tooHigh(e.key)) ? null : e;
1428 }
1429
1430 final TreeMap.Entry<K,V> absHighest() {
1431 TreeMap.Entry<K,V> e =
1432 (toEnd ? m.getLastEntry() :
1433 (hiInclusive ? m.getFloorEntry(hi) :
1434 m.getLowerEntry(hi)));
1435 return (e == null || tooLow(e.key)) ? null : e;
1436 }
1437
1438 final TreeMap.Entry<K,V> absCeiling(K key) {
1439 if (tooLow(key))
1440 return absLowest();
1441 TreeMap.Entry<K,V> e = m.getCeilingEntry(key);
1442 return (e == null || tooHigh(e.key)) ? null : e;
1443 }
1444
1445 final TreeMap.Entry<K,V> absHigher(K key) {
1446 if (tooLow(key))
1447 return absLowest();
1448 TreeMap.Entry<K,V> e = m.getHigherEntry(key);
1449 return (e == null || tooHigh(e.key)) ? null : e;
1450 }
1451
1452 final TreeMap.Entry<K,V> absFloor(K key) {
1453 if (tooHigh(key))
1454 return absHighest();
1455 TreeMap.Entry<K,V> e = m.getFloorEntry(key);
1456 return (e == null || tooLow(e.key)) ? null : e;
1457 }
1458
1459 final TreeMap.Entry<K,V> absLower(K key) {
1460 if (tooHigh(key))
1461 return absHighest();
1462 TreeMap.Entry<K,V> e = m.getLowerEntry(key);
1463 return (e == null || tooLow(e.key)) ? null : e;
1464 }
1465
1466 /** Returns the absolute high fence for ascending traversal */
1467 final TreeMap.Entry<K,V> absHighFence() {
1468 return (toEnd ? null : (hiInclusive ?
1469 m.getHigherEntry(hi) :
1470 m.getCeilingEntry(hi)));
1471 }
1472
1473 /** Return the absolute low fence for descending traversal */
1474 final TreeMap.Entry<K,V> absLowFence() {
1475 return (fromStart ? null : (loInclusive ?
1476 m.getLowerEntry(lo) :
1477 m.getFloorEntry(lo)));
1478 }
1479
1480 // Abstract methods defined in ascending vs descending classes
1481 // These relay to the appropriate absolute versions
1482
1483 abstract TreeMap.Entry<K,V> subLowest();
1484 abstract TreeMap.Entry<K,V> subHighest();
1485 abstract TreeMap.Entry<K,V> subCeiling(K key);
1486 abstract TreeMap.Entry<K,V> subHigher(K key);
1487 abstract TreeMap.Entry<K,V> subFloor(K key);
1488 abstract TreeMap.Entry<K,V> subLower(K key);
1489
1490 /** Returns ascending iterator from the perspective of this submap */
1491 abstract Iterator<K> keyIterator();
1492
1493 abstract Spliterator<K> keySpliterator();
1494
1495 /** Returns descending iterator from the perspective of this submap */
1496 abstract Iterator<K> descendingKeyIterator();
1497
1498 // public methods
1499
1500 public boolean isEmpty() {
1501 return (fromStart && toEnd) ? m.isEmpty() : entrySet().isEmpty();
1502 }
1503
1504 public int size() {
1505 return (fromStart && toEnd) ? m.size() : entrySet().size();
1506 }
1507
1508 public final boolean containsKey(Object key) {
1509 return inRange(key) && m.containsKey(key);
1510 }
1511
1512 public final V put(K key, V value) {
1513 if (!inRange(key))
1514 throw new IllegalArgumentException("key out of range");
1515 return m.put(key, value);
1516 }
1517
1518 public final V get(Object key) {
1519 return !inRange(key) ? null : m.get(key);
1520 }
1521
1522 public final V remove(Object key) {
1523 return !inRange(key) ? null : m.remove(key);
1524 }
1525
1526 public final Map.Entry<K,V> ceilingEntry(K key) {
1527 return exportEntry(subCeiling(key));
1528 }
1529
1530 public final K ceilingKey(K key) {
1531 return keyOrNull(subCeiling(key));
1532 }
1533
1534 public final Map.Entry<K,V> higherEntry(K key) {
1535 return exportEntry(subHigher(key));
1536 }
1537
1538 public final K higherKey(K key) {
1539 return keyOrNull(subHigher(key));
1540 }
1541
1542 public final Map.Entry<K,V> floorEntry(K key) {
1543 return exportEntry(subFloor(key));
1544 }
1545
1546 public final K floorKey(K key) {
1547 return keyOrNull(subFloor(key));
1548 }
1549
1550 public final Map.Entry<K,V> lowerEntry(K key) {
1551 return exportEntry(subLower(key));
1552 }
1553
1554 public final K lowerKey(K key) {
1555 return keyOrNull(subLower(key));
1556 }
1557
1558 public final K firstKey() {
1559 return key(subLowest());
1560 }
1561
1562 public final K lastKey() {
1563 return key(subHighest());
1564 }
1565
1566 public final Map.Entry<K,V> firstEntry() {
1567 return exportEntry(subLowest());
1568 }
1569
1570 public final Map.Entry<K,V> lastEntry() {
1571 return exportEntry(subHighest());
1572 }
1573
1574 public final Map.Entry<K,V> pollFirstEntry() {
1575 TreeMap.Entry<K,V> e = subLowest();
1576 Map.Entry<K,V> result = exportEntry(e);
1577 if (e != null)
1578 m.deleteEntry(e);
1579 return result;
1580 }
1581
1582 public final Map.Entry<K,V> pollLastEntry() {
1583 TreeMap.Entry<K,V> e = subHighest();
1584 Map.Entry<K,V> result = exportEntry(e);
1585 if (e != null)
1586 m.deleteEntry(e);
1587 return result;
1588 }
1589
1590 // Views
1591 transient NavigableMap<K,V> descendingMapView;
1592 transient EntrySetView entrySetView;
1593 transient KeySet<K> navigableKeySetView;
1594
1595 public final NavigableSet<K> navigableKeySet() {
1596 KeySet<K> nksv = navigableKeySetView;
1597 return (nksv != null) ? nksv :
1598 (navigableKeySetView = new TreeMap.KeySet<>(this));
1599 }
1600
1601 public final Set<K> keySet() {
1602 return navigableKeySet();
1603 }
1604
1605 public NavigableSet<K> descendingKeySet() {
1606 return descendingMap().navigableKeySet();
1607 }
1608
1609 public final SortedMap<K,V> subMap(K fromKey, K toKey) {
1610 return subMap(fromKey, true, toKey, false);
1611 }
1612
1613 public final SortedMap<K,V> headMap(K toKey) {
1614 return headMap(toKey, false);
1615 }
1616
1617 public final SortedMap<K,V> tailMap(K fromKey) {
1618 return tailMap(fromKey, true);
1619 }
1620
1621 // View classes
1622
1623 abstract class EntrySetView extends AbstractSet<Map.Entry<K,V>> {
1624 private transient int size = -1, sizeModCount;
1625
1626 public int size() {
1627 if (fromStart && toEnd)
1628 return m.size();
1629 if (size == -1 || sizeModCount != m.modCount) {
1630 sizeModCount = m.modCount;
1631 size = 0;
1632 Iterator<?> i = iterator();
1633 while (i.hasNext()) {
1634 size++;
1635 i.next();
1636 }
1637 }
1638 return size;
1639 }
1640
1641 public boolean isEmpty() {
1642 TreeMap.Entry<K,V> n = absLowest();
1643 return n == null || tooHigh(n.key);
1644 }
1645
1646 public boolean contains(Object o) {
1647 if (!(o instanceof Map.Entry))
1648 return false;
1649 Map.Entry<?,?> entry = (Map.Entry<?,?>) o;
1650 Object key = entry.getKey();
1651 if (!inRange(key))
1652 return false;
1653 TreeMap.Entry<?,?> node = m.getEntry(key);
1654 return node != null &&
1655 valEquals(node.getValue(), entry.getValue());
1656 }
1657
1658 public boolean remove(Object o) {
1659 if (!(o instanceof Map.Entry))
1660 return false;
1661 Map.Entry<?,?> entry = (Map.Entry<?,?>) o;
1662 Object key = entry.getKey();
1663 if (!inRange(key))
1664 return false;
1665 TreeMap.Entry<K,V> node = m.getEntry(key);
1666 if (node!=null && valEquals(node.getValue(),
1667 entry.getValue())) {
1668 m.deleteEntry(node);
1669 return true;
1670 }
1671 return false;
1672 }
1673 }
1674
1675 /**
1676 * Iterators for SubMaps
1677 */
1678 abstract class SubMapIterator<T> implements Iterator<T> {
1679 TreeMap.Entry<K,V> lastReturned;
1680 TreeMap.Entry<K,V> next;
1681 final Object fenceKey;
1682 int expectedModCount;
1683
1684 SubMapIterator(TreeMap.Entry<K,V> first,
1685 TreeMap.Entry<K,V> fence) {
1686 expectedModCount = m.modCount;
1687 lastReturned = null;
1688 next = first;
1689 fenceKey = fence == null ? UNBOUNDED : fence.key;
1690 }
1691
1692 public final boolean hasNext() {
1693 return next != null && next.key != fenceKey;
1694 }
1695
1696 final TreeMap.Entry<K,V> nextEntry() {
1697 TreeMap.Entry<K,V> e = next;
1698 if (e == null || e.key == fenceKey)
1699 throw new NoSuchElementException();
1700 if (m.modCount != expectedModCount)
1701 throw new ConcurrentModificationException();
1702 next = successor(e);
1703 lastReturned = e;
1704 return e;
1705 }
1706
1707 final TreeMap.Entry<K,V> prevEntry() {
1708 TreeMap.Entry<K,V> e = next;
1709 if (e == null || e.key == fenceKey)
1710 throw new NoSuchElementException();
1711 if (m.modCount != expectedModCount)
1712 throw new ConcurrentModificationException();
1713 next = predecessor(e);
1714 lastReturned = e;
1715 return e;
1716 }
1717
1718 final void removeAscending() {
1719 if (lastReturned == null)
1720 throw new IllegalStateException();
1721 if (m.modCount != expectedModCount)
1722 throw new ConcurrentModificationException();
1723 // deleted entries are replaced by their successors
1724 if (lastReturned.left != null && lastReturned.right != null)
1725 next = lastReturned;
1726 m.deleteEntry(lastReturned);
1727 lastReturned = null;
1728 expectedModCount = m.modCount;
1729 }
1730
1731 final void removeDescending() {
1732 if (lastReturned == null)
1733 throw new IllegalStateException();
1734 if (m.modCount != expectedModCount)
1735 throw new ConcurrentModificationException();
1736 m.deleteEntry(lastReturned);
1737 lastReturned = null;
1738 expectedModCount = m.modCount;
1739 }
1740
1741 }
1742
1743 final class SubMapEntryIterator extends SubMapIterator<Map.Entry<K,V>> {
1744 SubMapEntryIterator(TreeMap.Entry<K,V> first,
1745 TreeMap.Entry<K,V> fence) {
1746 super(first, fence);
1747 }
1748 public Map.Entry<K,V> next() {
1749 return nextEntry();
1750 }
1751 public void remove() {
1752 removeAscending();
1753 }
1754 }
1755
1756 final class DescendingSubMapEntryIterator extends SubMapIterator<Map.Entry<K,V>> {
1757 DescendingSubMapEntryIterator(TreeMap.Entry<K,V> last,
1758 TreeMap.Entry<K,V> fence) {
1759 super(last, fence);
1760 }
1761
1762 public Map.Entry<K,V> next() {
1763 return prevEntry();
1764 }
1765 public void remove() {
1766 removeDescending();
1767 }
1768 }
1769
1770 // Implement minimal Spliterator as KeySpliterator backup
1771 final class SubMapKeyIterator extends SubMapIterator<K>
1772 implements Spliterator<K> {
1773 SubMapKeyIterator(TreeMap.Entry<K,V> first,
1774 TreeMap.Entry<K,V> fence) {
1775 super(first, fence);
1776 }
1777 public K next() {
1778 return nextEntry().key;
1779 }
1780 public void remove() {
1781 removeAscending();
1782 }
1783 public Spliterator<K> trySplit() {
1784 return null;
1785 }
1786 public void forEachRemaining(Consumer<? super K> action) {
1787 while (hasNext())
1788 action.accept(next());
1789 }
1790 public boolean tryAdvance(Consumer<? super K> action) {
1791 if (hasNext()) {
1792 action.accept(next());
1793 return true;
1794 }
1795 return false;
1796 }
1797 public long estimateSize() {
1798 return Long.MAX_VALUE;
1799 }
1800 public int characteristics() {
1801 return Spliterator.DISTINCT | Spliterator.ORDERED |
1802 Spliterator.SORTED;
1803 }
1804 public final Comparator<? super K> getComparator() {
1805 return NavigableSubMap.this.comparator();
1806 }
1807 }
1808
1809 final class DescendingSubMapKeyIterator extends SubMapIterator<K>
1810 implements Spliterator<K> {
1811 DescendingSubMapKeyIterator(TreeMap.Entry<K,V> last,
1812 TreeMap.Entry<K,V> fence) {
1813 super(last, fence);
1814 }
1815 public K next() {
1816 return prevEntry().key;
1817 }
1818 public void remove() {
1819 removeDescending();
1820 }
1821 public Spliterator<K> trySplit() {
1822 return null;
1823 }
1824 public void forEachRemaining(Consumer<? super K> action) {
1825 while (hasNext())
1826 action.accept(next());
1827 }
1828 public boolean tryAdvance(Consumer<? super K> action) {
1829 if (hasNext()) {
1830 action.accept(next());
1831 return true;
1832 }
1833 return false;
1834 }
1835 public long estimateSize() {
1836 return Long.MAX_VALUE;
1837 }
1838 public int characteristics() {
1839 return Spliterator.DISTINCT | Spliterator.ORDERED;
1840 }
1841 }
1842 }
1843
1844 /**
1845 * @serial include
1846 */
1847 static final class AscendingSubMap<K,V> extends NavigableSubMap<K,V> {
1848 @java.io.Serial
1849 private static final long serialVersionUID = 912986545866124060L;
1850
1851 AscendingSubMap(TreeMap<K,V> m,
1852 boolean fromStart, K lo, boolean loInclusive,
1853 boolean toEnd, K hi, boolean hiInclusive) {
1854 super(m, fromStart, lo, loInclusive, toEnd, hi, hiInclusive);
1855 }
1856
1857 public Comparator<? super K> comparator() {
1858 return m.comparator();
1859 }
1860
1861 public NavigableMap<K,V> subMap(K fromKey, boolean fromInclusive,
1862 K toKey, boolean toInclusive) {
1863 if (!inRange(fromKey, fromInclusive))
1864 throw new IllegalArgumentException("fromKey out of range");
1865 if (!inRange(toKey, toInclusive))
1866 throw new IllegalArgumentException("toKey out of range");
1867 return new AscendingSubMap<>(m,
1868 false, fromKey, fromInclusive,
1869 false, toKey, toInclusive);
1870 }
1871
1872 public NavigableMap<K,V> headMap(K toKey, boolean inclusive) {
1873 if (!inRange(toKey, inclusive))
1874 throw new IllegalArgumentException("toKey out of range");
1875 return new AscendingSubMap<>(m,
1876 fromStart, lo, loInclusive,
1877 false, toKey, inclusive);
1878 }
1879
1880 public NavigableMap<K,V> tailMap(K fromKey, boolean inclusive) {
1881 if (!inRange(fromKey, inclusive))
1882 throw new IllegalArgumentException("fromKey out of range");
1883 return new AscendingSubMap<>(m,
1884 false, fromKey, inclusive,
1885 toEnd, hi, hiInclusive);
1886 }
1887
1888 public NavigableMap<K,V> descendingMap() {
1889 NavigableMap<K,V> mv = descendingMapView;
1890 return (mv != null) ? mv :
1891 (descendingMapView =
1892 new DescendingSubMap<>(m,
1893 fromStart, lo, loInclusive,
1894 toEnd, hi, hiInclusive));
1895 }
1896
1897 Iterator<K> keyIterator() {
1898 return new SubMapKeyIterator(absLowest(), absHighFence());
1899 }
1900
1901 Spliterator<K> keySpliterator() {
1902 return new SubMapKeyIterator(absLowest(), absHighFence());
1903 }
1904
1905 Iterator<K> descendingKeyIterator() {
1906 return new DescendingSubMapKeyIterator(absHighest(), absLowFence());
1907 }
1908
1909 final class AscendingEntrySetView extends EntrySetView {
1910 public Iterator<Map.Entry<K,V>> iterator() {
1911 return new SubMapEntryIterator(absLowest(), absHighFence());
1912 }
1913 }
1914
1915 public Set<Map.Entry<K,V>> entrySet() {
1916 EntrySetView es = entrySetView;
1917 return (es != null) ? es : (entrySetView = new AscendingEntrySetView());
1918 }
1919
1920 TreeMap.Entry<K,V> subLowest() { return absLowest(); }
1921 TreeMap.Entry<K,V> subHighest() { return absHighest(); }
1922 TreeMap.Entry<K,V> subCeiling(K key) { return absCeiling(key); }
1923 TreeMap.Entry<K,V> subHigher(K key) { return absHigher(key); }
1924 TreeMap.Entry<K,V> subFloor(K key) { return absFloor(key); }
1925 TreeMap.Entry<K,V> subLower(K key) { return absLower(key); }
1926 }
1927
1928 /**
1929 * @serial include
1930 */
1931 static final class DescendingSubMap<K,V> extends NavigableSubMap<K,V> {
1932 @java.io.Serial
1933 private static final long serialVersionUID = 912986545866120460L;
1934 DescendingSubMap(TreeMap<K,V> m,
1935 boolean fromStart, K lo, boolean loInclusive,
1936 boolean toEnd, K hi, boolean hiInclusive) {
1937 super(m, fromStart, lo, loInclusive, toEnd, hi, hiInclusive);
1938 }
1939
1940 private final Comparator<? super K> reverseComparator =
1941 Collections.reverseOrder(m.comparator);
1942
1943 public Comparator<? super K> comparator() {
1944 return reverseComparator;
1945 }
1946
1947 public NavigableMap<K,V> subMap(K fromKey, boolean fromInclusive,
1948 K toKey, boolean toInclusive) {
1949 if (!inRange(fromKey, fromInclusive))
1950 throw new IllegalArgumentException("fromKey out of range");
1951 if (!inRange(toKey, toInclusive))
1952 throw new IllegalArgumentException("toKey out of range");
1953 return new DescendingSubMap<>(m,
1954 false, toKey, toInclusive,
1955 false, fromKey, fromInclusive);
1956 }
1957
1958 public NavigableMap<K,V> headMap(K toKey, boolean inclusive) {
1959 if (!inRange(toKey, inclusive))
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 if (!inRange(fromKey, inclusive))
1968 throw new IllegalArgumentException("fromKey out of range");
1969 return new DescendingSubMap<>(m,
1970 fromStart, lo, loInclusive,
1971 false, fromKey, inclusive);
1972 }
1973
1974 public NavigableMap<K,V> descendingMap() {
1975 NavigableMap<K,V> mv = descendingMapView;
1976 return (mv != null) ? mv :
1977 (descendingMapView =
1978 new AscendingSubMap<>(m,
1979 fromStart, lo, loInclusive,
1980 toEnd, hi, hiInclusive));
1981 }
1982
1983 Iterator<K> keyIterator() {
1984 return new DescendingSubMapKeyIterator(absHighest(), absLowFence());
1985 }
1986
1987 Spliterator<K> keySpliterator() {
1988 return new DescendingSubMapKeyIterator(absHighest(), absLowFence());
1989 }
1990
1991 Iterator<K> descendingKeyIterator() {
1992 return new SubMapKeyIterator(absLowest(), absHighFence());
1993 }
1994
1995 final class DescendingEntrySetView extends EntrySetView {
1996 public Iterator<Map.Entry<K,V>> iterator() {
1997 return new DescendingSubMapEntryIterator(absHighest(), absLowFence());
1998 }
1999 }
2000
2001 public Set<Map.Entry<K,V>> entrySet() {
2002 EntrySetView es = entrySetView;
2003 return (es != null) ? es : (entrySetView = new DescendingEntrySetView());
2004 }
2005
2006 TreeMap.Entry<K,V> subLowest() { return absHighest(); }
2007 TreeMap.Entry<K,V> subHighest() { return absLowest(); }
2008 TreeMap.Entry<K,V> subCeiling(K key) { return absFloor(key); }
2009 TreeMap.Entry<K,V> subHigher(K key) { return absLower(key); }
2010 TreeMap.Entry<K,V> subFloor(K key) { return absCeiling(key); }
2011 TreeMap.Entry<K,V> subLower(K key) { return absHigher(key); }
2012 }
2013
2014 /**
2015 * This class exists solely for the sake of serialization
2016 * compatibility with previous releases of TreeMap that did not
2017 * support NavigableMap. It translates an old-version SubMap into
2018 * a new-version AscendingSubMap. This class is never otherwise
2019 * used.
2020 *
2021 * @serial include
2022 */
2023 private class SubMap extends AbstractMap<K,V>
2024 implements SortedMap<K,V>, java.io.Serializable {
2025 @java.io.Serial
2026 private static final long serialVersionUID = -6520786458950516097L;
2027 private boolean fromStart = false, toEnd = false;
2028 private K fromKey, toKey;
2029 @java.io.Serial
2030 private Object readResolve() {
2031 return new AscendingSubMap<>(TreeMap.this,
2032 fromStart, fromKey, true,
2033 toEnd, toKey, false);
2034 }
2035 public Set<Map.Entry<K,V>> entrySet() { throw new InternalError(); }
2036 public K lastKey() { throw new InternalError(); }
2037 public K firstKey() { throw new InternalError(); }
2038 public SortedMap<K,V> subMap(K fromKey, K toKey) { throw new InternalError(); }
2039 public SortedMap<K,V> headMap(K toKey) { throw new InternalError(); }
2040 public SortedMap<K,V> tailMap(K fromKey) { throw new InternalError(); }
2041 public Comparator<? super K> comparator() { throw new InternalError(); }
2042 }
2043
2044
2045 // Red-black mechanics
2046
2047 private static final boolean RED = false;
2048 private static final boolean BLACK = true;
2049
2050 /**
2051 * Node in the Tree. Doubles as a means to pass key-value pairs back to
2052 * user (see Map.Entry).
2053 */
2054
2055 static final class Entry<K,V> implements Map.Entry<K,V> {
2056 K key;
2057 V value;
2058 Entry<K,V> left;
2059 Entry<K,V> right;
2060 Entry<K,V> parent;
2061 boolean color = BLACK;
2062
2063 /**
2064 * Make a new cell with given key, value, and parent, and with
2065 * {@code null} child links, and BLACK color.
2066 */
2067 Entry(K key, V value, Entry<K,V> parent) {
2068 this.key = key;
2069 this.value = value;
2070 this.parent = parent;
2071 }
2072
2073 /**
2074 * Returns the key.
2075 *
2076 * @return the key
2077 */
2078 public K getKey() {
2079 return key;
2080 }
2081
2082 /**
2083 * Returns the value associated with the key.
2084 *
2085 * @return the value associated with the key
2086 */
2087 public V getValue() {
2088 return value;
2089 }
2090
2091 /**
2092 * Replaces the value currently associated with the key with the given
2093 * value.
2094 *
2095 * @return the value associated with the key before this method was
2096 * called
2097 */
2098 public V setValue(V value) {
2099 V oldValue = this.value;
2100 this.value = value;
2101 return oldValue;
2102 }
2103
2104 public boolean equals(Object o) {
2105 if (!(o instanceof Map.Entry))
2106 return false;
2107 Map.Entry<?,?> e = (Map.Entry<?,?>)o;
2108
2109 return valEquals(key,e.getKey()) && valEquals(value,e.getValue());
2110 }
2111
2112 public int hashCode() {
2113 int keyHash = (key==null ? 0 : key.hashCode());
2114 int valueHash = (value==null ? 0 : value.hashCode());
2115 return keyHash ^ valueHash;
2116 }
2117
2118 public String toString() {
2119 return key + "=" + value;
2120 }
2121 }
2122
2123 /**
2124 * Returns the first Entry in the TreeMap (according to the TreeMap's
2125 * key-sort function). Returns null if the TreeMap is empty.
2126 */
2127 final Entry<K,V> getFirstEntry() {
2128 Entry<K,V> p = root;
2129 if (p != null)
2130 while (p.left != null)
2131 p = p.left;
2132 return p;
2133 }
2134
2135 /**
2136 * Returns the last Entry in the TreeMap (according to the TreeMap's
2137 * key-sort function). Returns null if the TreeMap is empty.
2138 */
2139 final Entry<K,V> getLastEntry() {
2140 Entry<K,V> p = root;
2141 if (p != null)
2142 while (p.right != null)
2143 p = p.right;
2144 return p;
2145 }
2146
2147 /**
2148 * Returns the successor of the specified Entry, or null if no such.
2149 */
2150 static <K,V> TreeMap.Entry<K,V> successor(Entry<K,V> t) {
2151 if (t == null)
2152 return null;
2153 else if (t.right != null) {
2154 Entry<K,V> p = t.right;
2155 while (p.left != null)
2156 p = p.left;
2157 return p;
2158 } else {
2159 Entry<K,V> p = t.parent;
2160 Entry<K,V> ch = t;
2161 while (p != null && ch == p.right) {
2162 ch = p;
2163 p = p.parent;
2164 }
2165 return p;
2166 }
2167 }
2168
2169 /**
2170 * Returns the predecessor of the specified Entry, or null if no such.
2171 */
2172 static <K,V> Entry<K,V> predecessor(Entry<K,V> t) {
2173 if (t == null)
2174 return null;
2175 else if (t.left != null) {
2176 Entry<K,V> p = t.left;
2177 while (p.right != null)
2178 p = p.right;
2179 return p;
2180 } else {
2181 Entry<K,V> p = t.parent;
2182 Entry<K,V> ch = t;
2183 while (p != null && ch == p.left) {
2184 ch = p;
2185 p = p.parent;
2186 }
2187 return p;
2188 }
2189 }
2190
2191 /**
2192 * Balancing operations.
2193 *
2194 * Implementations of rebalancings during insertion and deletion are
2195 * slightly different than the CLR version. Rather than using dummy
2196 * nilnodes, we use a set of accessors that deal properly with null. They
2197 * are used to avoid messiness surrounding nullness checks in the main
2198 * algorithms.
2199 */
2200
2201 private static <K,V> boolean colorOf(Entry<K,V> p) {
2202 return (p == null ? BLACK : p.color);
2203 }
2204
2205 private static <K,V> Entry<K,V> parentOf(Entry<K,V> p) {
2206 return (p == null ? null: p.parent);
2207 }
2208
2209 private static <K,V> void setColor(Entry<K,V> p, boolean c) {
2210 if (p != null)
2211 p.color = c;
2212 }
2213
2214 private static <K,V> Entry<K,V> leftOf(Entry<K,V> p) {
2215 return (p == null) ? null: p.left;
2216 }
2217
2218 private static <K,V> Entry<K,V> rightOf(Entry<K,V> p) {
2219 return (p == null) ? null: p.right;
2220 }
2221
2222 /** From CLR */
2223 private void rotateLeft(Entry<K,V> p) {
2224 if (p != null) {
2225 Entry<K,V> r = p.right;
2226 p.right = r.left;
2227 if (r.left != null)
2228 r.left.parent = p;
2229 r.parent = p.parent;
2230 if (p.parent == null)
2231 root = r;
2232 else if (p.parent.left == p)
2233 p.parent.left = r;
2234 else
2235 p.parent.right = r;
2236 r.left = p;
2237 p.parent = r;
2238 }
2239 }
2240
2241 /** From CLR */
2242 private void rotateRight(Entry<K,V> p) {
2243 if (p != null) {
2244 Entry<K,V> l = p.left;
2245 p.left = l.right;
2246 if (l.right != null) l.right.parent = p;
2247 l.parent = p.parent;
2248 if (p.parent == null)
2249 root = l;
2250 else if (p.parent.right == p)
2251 p.parent.right = l;
2252 else p.parent.left = l;
2253 l.right = p;
2254 p.parent = l;
2255 }
2256 }
2257
2258 /** From CLR */
2259 private void fixAfterInsertion(Entry<K,V> x) {
2260 x.color = RED;
2261
2262 while (x != null && x != root && x.parent.color == RED) {
2263 if (parentOf(x) == leftOf(parentOf(parentOf(x)))) {
2264 Entry<K,V> y = rightOf(parentOf(parentOf(x)));
2265 if (colorOf(y) == RED) {
2266 setColor(parentOf(x), BLACK);
2267 setColor(y, BLACK);
2268 setColor(parentOf(parentOf(x)), RED);
2269 x = parentOf(parentOf(x));
2270 } else {
2271 if (x == rightOf(parentOf(x))) {
2272 x = parentOf(x);
2273 rotateLeft(x);
2274 }
2275 setColor(parentOf(x), BLACK);
2276 setColor(parentOf(parentOf(x)), RED);
2277 rotateRight(parentOf(parentOf(x)));
2278 }
2279 } else {
2280 Entry<K,V> y = leftOf(parentOf(parentOf(x)));
2281 if (colorOf(y) == RED) {
2282 setColor(parentOf(x), BLACK);
2283 setColor(y, BLACK);
2284 setColor(parentOf(parentOf(x)), RED);
2285 x = parentOf(parentOf(x));
2286 } else {
2287 if (x == leftOf(parentOf(x))) {
2288 x = parentOf(x);
2289 rotateRight(x);
2290 }
2291 setColor(parentOf(x), BLACK);
2292 setColor(parentOf(parentOf(x)), RED);
2293 rotateLeft(parentOf(parentOf(x)));
2294 }
2295 }
2296 }
2297 root.color = BLACK;
2298 }
2299
2300 /**
2301 * Delete node p, and then rebalance the tree.
2302 */
2303 private void deleteEntry(Entry<K,V> p) {
2304 modCount++;
2305 size--;
2306
2307 // If strictly internal, copy successor's element to p and then make p
2308 // point to successor.
2309 if (p.left != null && p.right != null) {
2310 Entry<K,V> s = successor(p);
2311 p.key = s.key;
2312 p.value = s.value;
2313 p = s;
2314 } // p has 2 children
2315
2316 // Start fixup at replacement node, if it exists.
2317 Entry<K,V> replacement = (p.left != null ? p.left : p.right);
2318
2319 if (replacement != null) {
2320 // Link replacement to parent
2321 replacement.parent = p.parent;
2322 if (p.parent == null)
2323 root = replacement;
2324 else if (p == p.parent.left)
2325 p.parent.left = replacement;
2326 else
2327 p.parent.right = replacement;
2328
2329 // Null out links so they are OK to use by fixAfterDeletion.
2330 p.left = p.right = p.parent = null;
2331
2332 // Fix replacement
2333 if (p.color == BLACK)
2334 fixAfterDeletion(replacement);
2335 } else if (p.parent == null) { // return if we are the only node.
2336 root = null;
2337 } else { // No children. Use self as phantom replacement and unlink.
2338 if (p.color == BLACK)
2339 fixAfterDeletion(p);
2340
2341 if (p.parent != null) {
2342 if (p == p.parent.left)
2343 p.parent.left = null;
2344 else if (p == p.parent.right)
2345 p.parent.right = null;
2346 p.parent = null;
2347 }
2348 }
2349 }
2350
2351 /** From CLR */
2352 private void fixAfterDeletion(Entry<K,V> x) {
2353 while (x != root && colorOf(x) == BLACK) {
2354 if (x == leftOf(parentOf(x))) {
2355 Entry<K,V> sib = rightOf(parentOf(x));
2356
2357 if (colorOf(sib) == RED) {
2358 setColor(sib, BLACK);
2359 setColor(parentOf(x), RED);
2360 rotateLeft(parentOf(x));
2361 sib = rightOf(parentOf(x));
2362 }
2363
2364 if (colorOf(leftOf(sib)) == BLACK &&
2365 colorOf(rightOf(sib)) == BLACK) {
2366 setColor(sib, RED);
2367 x = parentOf(x);
2368 } else {
2369 if (colorOf(rightOf(sib)) == BLACK) {
2370 setColor(leftOf(sib), BLACK);
2371 setColor(sib, RED);
2372 rotateRight(sib);
2373 sib = rightOf(parentOf(x));
2374 }
2375 setColor(sib, colorOf(parentOf(x)));
2376 setColor(parentOf(x), BLACK);
2377 setColor(rightOf(sib), BLACK);
2378 rotateLeft(parentOf(x));
2379 x = root;
2380 }
2381 } else { // symmetric
2382 Entry<K,V> sib = leftOf(parentOf(x));
2383
2384 if (colorOf(sib) == RED) {
2385 setColor(sib, BLACK);
2386 setColor(parentOf(x), RED);
2387 rotateRight(parentOf(x));
2388 sib = leftOf(parentOf(x));
2389 }
2390
2391 if (colorOf(rightOf(sib)) == BLACK &&
2392 colorOf(leftOf(sib)) == BLACK) {
2393 setColor(sib, RED);
2394 x = parentOf(x);
2395 } else {
2396 if (colorOf(leftOf(sib)) == BLACK) {
2397 setColor(rightOf(sib), BLACK);
2398 setColor(sib, RED);
2399 rotateLeft(sib);
2400 sib = leftOf(parentOf(x));
2401 }
2402 setColor(sib, colorOf(parentOf(x)));
2403 setColor(parentOf(x), BLACK);
2404 setColor(leftOf(sib), BLACK);
2405 rotateRight(parentOf(x));
2406 x = root;
2407 }
2408 }
2409 }
2410
2411 setColor(x, BLACK);
2412 }
2413
2414 @java.io.Serial
2415 private static final long serialVersionUID = 919286545866124006L;
2416
2417 /**
2418 * Save the state of the {@code TreeMap} instance to a stream (i.e.,
2419 * serialize it).
2420 *
2421 * @serialData The <em>size</em> of the TreeMap (the number of key-value
2422 * mappings) is emitted (int), followed by the key (Object)
2423 * and value (Object) for each key-value mapping represented
2424 * by the TreeMap. The key-value mappings are emitted in
2425 * key-order (as determined by the TreeMap's Comparator,
2426 * or by the keys' natural ordering if the TreeMap has no
2427 * Comparator).
2428 */
2429 @java.io.Serial
2430 private void writeObject(java.io.ObjectOutputStream s)
2431 throws java.io.IOException {
2432 // Write out the Comparator and any hidden stuff
2433 s.defaultWriteObject();
2434
2435 // Write out size (number of Mappings)
2436 s.writeInt(size);
2437
2438 // Write out keys and values (alternating)
2439 for (Map.Entry<K, V> e : entrySet()) {
2440 s.writeObject(e.getKey());
2441 s.writeObject(e.getValue());
2442 }
2443 }
2444
2445 /**
2446 * Reconstitute the {@code TreeMap} instance from a stream (i.e.,
2447 * deserialize it).
2448 */
2449 @java.io.Serial
2450 private void readObject(final java.io.ObjectInputStream s)
2451 throws java.io.IOException, ClassNotFoundException {
2452 // Read in the Comparator and any hidden stuff
2453 s.defaultReadObject();
2454
2455 // Read in size
2456 int size = s.readInt();
2457
2458 buildFromSorted(size, null, s, null);
2459 }
2460
2461 /** Intended to be called only from TreeSet.readObject */
2462 void readTreeSet(int size, java.io.ObjectInputStream s, V defaultVal)
2463 throws java.io.IOException, ClassNotFoundException {
2464 buildFromSorted(size, null, s, defaultVal);
2465 }
2466
2467 /** Intended to be called only from TreeSet.addAll */
2468 void addAllForTreeSet(SortedSet<? extends K> set, V defaultVal) {
2469 try {
2470 buildFromSorted(set.size(), set.iterator(), null, defaultVal);
2471 } catch (java.io.IOException | ClassNotFoundException cannotHappen) {
2472 }
2473 }
2474
2475
2476 /**
2477 * Linear time tree building algorithm from sorted data. Can accept keys
2478 * and/or values from iterator or stream. This leads to too many
2479 * parameters, but seems better than alternatives. The four formats
2480 * that this method accepts are:
2481 *
2482 * 1) An iterator of Map.Entries. (it != null, defaultVal == null).
2483 * 2) An iterator of keys. (it != null, defaultVal != null).
2484 * 3) A stream of alternating serialized keys and values.
2485 * (it == null, defaultVal == null).
2486 * 4) A stream of serialized keys. (it == null, defaultVal != null).
2487 *
2488 * It is assumed that the comparator of the TreeMap is already set prior
2489 * to calling this method.
2490 *
2491 * @param size the number of keys (or key-value pairs) to be read from
2492 * the iterator or stream
2493 * @param it If non-null, new entries are created from entries
2494 * or keys read from this iterator.
2495 * @param str If non-null, new entries are created from keys and
2496 * possibly values read from this stream in serialized form.
2497 * Exactly one of it and str should be non-null.
2498 * @param defaultVal if non-null, this default value is used for
2499 * each value in the map. If null, each value is read from
2500 * iterator or stream, as described above.
2501 * @throws java.io.IOException propagated from stream reads. This cannot
2502 * occur if str is null.
2503 * @throws ClassNotFoundException propagated from readObject.
2504 * This cannot occur if str is null.
2505 */
2506 private void buildFromSorted(int size, Iterator<?> it,
2507 java.io.ObjectInputStream str,
2508 V defaultVal)
2509 throws java.io.IOException, ClassNotFoundException {
2510 this.size = size;
2511 root = buildFromSorted(0, 0, size-1, computeRedLevel(size),
2512 it, str, defaultVal);
2513 }
2514
2515 /**
2516 * Recursive "helper method" that does the real work of the
2517 * previous method. Identically named parameters have
2518 * identical definitions. Additional parameters are documented below.
2519 * It is assumed that the comparator and size fields of the TreeMap are
2520 * already set prior to calling this method. (It ignores both fields.)
2521 *
2522 * @param level the current level of tree. Initial call should be 0.
2523 * @param lo the first element index of this subtree. Initial should be 0.
2524 * @param hi the last element index of this subtree. Initial should be
2525 * size-1.
2526 * @param redLevel the level at which nodes should be red.
2527 * Must be equal to computeRedLevel for tree of this size.
2528 */
2529 @SuppressWarnings("unchecked")
2530 private final Entry<K,V> buildFromSorted(int level, int lo, int hi,
2531 int redLevel,
2532 Iterator<?> it,
2533 java.io.ObjectInputStream str,
2534 V defaultVal)
2535 throws java.io.IOException, ClassNotFoundException {
2536 /*
2537 * Strategy: The root is the middlemost element. To get to it, we
2538 * have to first recursively construct the entire left subtree,
2539 * so as to grab all of its elements. We can then proceed with right
2540 * subtree.
2541 *
2542 * The lo and hi arguments are the minimum and maximum
2543 * indices to pull out of the iterator or stream for current subtree.
2544 * They are not actually indexed, we just proceed sequentially,
2545 * ensuring that items are extracted in corresponding order.
2546 */
2547
2548 if (hi < lo) return null;
2549
2550 int mid = (lo + hi) >>> 1;
2551
2552 Entry<K,V> left = null;
2553 if (lo < mid)
2554 left = buildFromSorted(level+1, lo, mid - 1, redLevel,
2555 it, str, defaultVal);
2556
2557 // extract key and/or value from iterator or stream
2558 K key;
2559 V value;
2560 if (it != null) {
2561 if (defaultVal==null) {
2562 Map.Entry<?,?> entry = (Map.Entry<?,?>)it.next();
2563 key = (K)entry.getKey();
2564 value = (V)entry.getValue();
2565 } else {
2566 key = (K)it.next();
2567 value = defaultVal;
2568 }
2569 } else { // use stream
2570 key = (K) str.readObject();
2571 value = (defaultVal != null ? defaultVal : (V) str.readObject());
2572 }
2573
2574 Entry<K,V> middle = new Entry<>(key, value, null);
2575
2576 // color nodes in non-full bottommost level red
2577 if (level == redLevel)
2578 middle.color = RED;
2579
2580 if (left != null) {
2581 middle.left = left;
2582 left.parent = middle;
2583 }
2584
2585 if (mid < hi) {
2586 Entry<K,V> right = buildFromSorted(level+1, mid+1, hi, redLevel,
2587 it, str, defaultVal);
2588 middle.right = right;
2589 right.parent = middle;
2590 }
2591
2592 return middle;
2593 }
2594
2595 /**
2596 * Finds the level down to which to assign all nodes BLACK. This is the
2597 * last `full' level of the complete binary tree produced by buildTree.
2598 * The remaining nodes are colored RED. (This makes a `nice' set of
2599 * color assignments wrt future insertions.) This level number is
2600 * computed by finding the number of splits needed to reach the zeroeth
2601 * node.
2602 *
2603 * @param size the (non-negative) number of keys in the tree to be built
2604 */
2605 private static int computeRedLevel(int size) {
2606 return 31 - Integer.numberOfLeadingZeros(size + 1);
2607 }
2608
2609 /**
2610 * Currently, we support Spliterator-based versions only for the
2611 * full map, in either plain of descending form, otherwise relying
2612 * on defaults because size estimation for submaps would dominate
2613 * costs. The type tests needed to check these for key views are
2614 * not very nice but avoid disrupting existing class
2615 * structures. Callers must use plain default spliterators if this
2616 * returns null.
2617 */
2618 static <K> Spliterator<K> keySpliteratorFor(NavigableMap<K,?> m) {
2619 if (m instanceof TreeMap) {
2620 @SuppressWarnings("unchecked") TreeMap<K,Object> t =
2621 (TreeMap<K,Object>) m;
2622 return t.keySpliterator();
2623 }
2624 if (m instanceof DescendingSubMap) {
2625 @SuppressWarnings("unchecked") DescendingSubMap<K,?> dm =
2626 (DescendingSubMap<K,?>) m;
2627 TreeMap<K,?> tm = dm.m;
2628 if (dm == tm.descendingMap) {
2629 @SuppressWarnings("unchecked") TreeMap<K,Object> t =
2630 (TreeMap<K,Object>) tm;
2631 return t.descendingKeySpliterator();
2632 }
2633 }
2634 @SuppressWarnings("unchecked") NavigableSubMap<K,?> sm =
2635 (NavigableSubMap<K,?>) m;
2636 return sm.keySpliterator();
2637 }
2638
2639 final Spliterator<K> keySpliterator() {
2640 return new KeySpliterator<>(this, null, null, 0, -1, 0);
2641 }
2642
2643 final Spliterator<K> descendingKeySpliterator() {
2644 return new DescendingKeySpliterator<>(this, null, null, 0, -2, 0);
2645 }
2646
2647 /**
2648 * Base class for spliterators. Iteration starts at a given
2649 * origin and continues up to but not including a given fence (or
2650 * null for end). At top-level, for ascending cases, the first
2651 * split uses the root as left-fence/right-origin. From there,
2652 * right-hand splits replace the current fence with its left
2653 * child, also serving as origin for the split-off spliterator.
2654 * Left-hands are symmetric. Descending versions place the origin
2655 * at the end and invert ascending split rules. This base class
2656 * is non-committal about directionality, or whether the top-level
2657 * spliterator covers the whole tree. This means that the actual
2658 * split mechanics are located in subclasses. Some of the subclass
2659 * trySplit methods are identical (except for return types), but
2660 * not nicely factorable.
2661 *
2662 * Currently, subclass versions exist only for the full map
2663 * (including descending keys via its descendingMap). Others are
2664 * possible but currently not worthwhile because submaps require
2665 * O(n) computations to determine size, which substantially limits
2666 * potential speed-ups of using custom Spliterators versus default
2667 * mechanics.
2668 *
2669 * To boostrap initialization, external constructors use
2670 * negative size estimates: -1 for ascend, -2 for descend.
2671 */
2672 static class TreeMapSpliterator<K,V> {
2673 final TreeMap<K,V> tree;
2674 TreeMap.Entry<K,V> current; // traverser; initially first node in range
2675 TreeMap.Entry<K,V> fence; // one past last, or null
2676 int side; // 0: top, -1: is a left split, +1: right
2677 int est; // size estimate (exact only for top-level)
2678 int expectedModCount; // for CME checks
2679
2680 TreeMapSpliterator(TreeMap<K,V> tree,
2681 TreeMap.Entry<K,V> origin, TreeMap.Entry<K,V> fence,
2682 int side, int est, int expectedModCount) {
2683 this.tree = tree;
2684 this.current = origin;
2685 this.fence = fence;
2686 this.side = side;
2687 this.est = est;
2688 this.expectedModCount = expectedModCount;
2689 }
2690
2691 final int getEstimate() { // force initialization
2692 int s; TreeMap<K,V> t;
2693 if ((s = est) < 0) {
2694 if ((t = tree) != null) {
2695 current = (s == -1) ? t.getFirstEntry() : t.getLastEntry();
2696 s = est = t.size;
2697 expectedModCount = t.modCount;
2698 }
2699 else
2700 s = est = 0;
2701 }
2702 return s;
2703 }
2704
2705 public final long estimateSize() {
2706 return (long)getEstimate();
2707 }
2708 }
2709
2710 static final class KeySpliterator<K,V>
2711 extends TreeMapSpliterator<K,V>
2712 implements Spliterator<K> {
2713 KeySpliterator(TreeMap<K,V> tree,
2714 TreeMap.Entry<K,V> origin, TreeMap.Entry<K,V> fence,
2715 int side, int est, int expectedModCount) {
2716 super(tree, origin, fence, side, est, expectedModCount);
2717 }
2718
2719 public KeySpliterator<K,V> trySplit() {
2720 if (est < 0)
2721 getEstimate(); // force initialization
2722 int d = side;
2723 TreeMap.Entry<K,V> e = current, f = fence,
2724 s = ((e == null || e == f) ? null : // empty
2725 (d == 0) ? tree.root : // was top
2726 (d > 0) ? e.right : // was right
2727 (d < 0 && f != null) ? f.left : // was left
2728 null);
2729 if (s != null && s != e && s != f &&
2730 tree.compare(e.key, s.key) < 0) { // e not already past s
2731 side = 1;
2732 return new KeySpliterator<>
2733 (tree, e, current = s, -1, est >>>= 1, expectedModCount);
2734 }
2735 return null;
2736 }
2737
2738 public void forEachRemaining(Consumer<? super K> action) {
2739 if (action == null)
2740 throw new NullPointerException();
2741 if (est < 0)
2742 getEstimate(); // force initialization
2743 TreeMap.Entry<K,V> f = fence, e, p, pl;
2744 if ((e = current) != null && e != f) {
2745 current = f; // exhaust
2746 do {
2747 action.accept(e.key);
2748 if ((p = e.right) != null) {
2749 while ((pl = p.left) != null)
2750 p = pl;
2751 }
2752 else {
2753 while ((p = e.parent) != null && e == p.right)
2754 e = p;
2755 }
2756 } while ((e = p) != null && e != f);
2757 if (tree.modCount != expectedModCount)
2758 throw new ConcurrentModificationException();
2759 }
2760 }
2761
2762 public boolean tryAdvance(Consumer<? super K> action) {
2763 TreeMap.Entry<K,V> e;
2764 if (action == null)
2765 throw new NullPointerException();
2766 if (est < 0)
2767 getEstimate(); // force initialization
2768 if ((e = current) == null || e == fence)
2769 return false;
2770 current = successor(e);
2771 action.accept(e.key);
2772 if (tree.modCount != expectedModCount)
2773 throw new ConcurrentModificationException();
2774 return true;
2775 }
2776
2777 public int characteristics() {
2778 return (side == 0 ? Spliterator.SIZED : 0) |
2779 Spliterator.DISTINCT | Spliterator.SORTED | Spliterator.ORDERED;
2780 }
2781
2782 public final Comparator<? super K> getComparator() {
2783 return tree.comparator;
2784 }
2785
2786 }
2787
2788 static final class DescendingKeySpliterator<K,V>
2789 extends TreeMapSpliterator<K,V>
2790 implements Spliterator<K> {
2791 DescendingKeySpliterator(TreeMap<K,V> tree,
2792 TreeMap.Entry<K,V> origin, TreeMap.Entry<K,V> fence,
2793 int side, int est, int expectedModCount) {
2794 super(tree, origin, fence, side, est, expectedModCount);
2795 }
2796
2797 public DescendingKeySpliterator<K,V> trySplit() {
2798 if (est < 0)
2799 getEstimate(); // force initialization
2800 int d = side;
2801 TreeMap.Entry<K,V> e = current, f = fence,
2802 s = ((e == null || e == f) ? null : // empty
2803 (d == 0) ? tree.root : // was top
2804 (d < 0) ? e.left : // was left
2805 (d > 0 && f != null) ? f.right : // was right
2806 null);
2807 if (s != null && s != e && s != f &&
2808 tree.compare(e.key, s.key) > 0) { // e not already past s
2809 side = 1;
2810 return new DescendingKeySpliterator<>
2811 (tree, e, current = s, -1, est >>>= 1, expectedModCount);
2812 }
2813 return null;
2814 }
2815
2816 public void forEachRemaining(Consumer<? super K> action) {
2817 if (action == null)
2818 throw new NullPointerException();
2819 if (est < 0)
2820 getEstimate(); // force initialization
2821 TreeMap.Entry<K,V> f = fence, e, p, pr;
2822 if ((e = current) != null && e != f) {
2823 current = f; // exhaust
2824 do {
2825 action.accept(e.key);
2826 if ((p = e.left) != null) {
2827 while ((pr = p.right) != null)
2828 p = pr;
2829 }
2830 else {
2831 while ((p = e.parent) != null && e == p.left)
2832 e = p;
2833 }
2834 } while ((e = p) != null && e != f);
2835 if (tree.modCount != expectedModCount)
2836 throw new ConcurrentModificationException();
2837 }
2838 }
2839
2840 public boolean tryAdvance(Consumer<? super K> action) {
2841 TreeMap.Entry<K,V> e;
2842 if (action == null)
2843 throw new NullPointerException();
2844 if (est < 0)
2845 getEstimate(); // force initialization
2846 if ((e = current) == null || e == fence)
2847 return false;
2848 current = predecessor(e);
2849 action.accept(e.key);
2850 if (tree.modCount != expectedModCount)
2851 throw new ConcurrentModificationException();
2852 return true;
2853 }
2854
2855 public int characteristics() {
2856 return (side == 0 ? Spliterator.SIZED : 0) |
2857 Spliterator.DISTINCT | Spliterator.ORDERED;
2858 }
2859 }
2860
2861 static final class ValueSpliterator<K,V>
2862 extends TreeMapSpliterator<K,V>
2863 implements Spliterator<V> {
2864 ValueSpliterator(TreeMap<K,V> tree,
2865 TreeMap.Entry<K,V> origin, TreeMap.Entry<K,V> fence,
2866 int side, int est, int expectedModCount) {
2867 super(tree, origin, fence, side, est, expectedModCount);
2868 }
2869
2870 public ValueSpliterator<K,V> trySplit() {
2871 if (est < 0)
2872 getEstimate(); // force initialization
2873 int d = side;
2874 TreeMap.Entry<K,V> e = current, f = fence,
2875 s = ((e == null || e == f) ? null : // empty
2876 (d == 0) ? tree.root : // was top
2877 (d > 0) ? e.right : // was right
2878 (d < 0 && f != null) ? f.left : // was left
2879 null);
2880 if (s != null && s != e && s != f &&
2881 tree.compare(e.key, s.key) < 0) { // e not already past s
2882 side = 1;
2883 return new ValueSpliterator<>
2884 (tree, e, current = s, -1, est >>>= 1, expectedModCount);
2885 }
2886 return null;
2887 }
2888
2889 public void forEachRemaining(Consumer<? super V> action) {
2890 if (action == null)
2891 throw new NullPointerException();
2892 if (est < 0)
2893 getEstimate(); // force initialization
2894 TreeMap.Entry<K,V> f = fence, e, p, pl;
2895 if ((e = current) != null && e != f) {
2896 current = f; // exhaust
2897 do {
2898 action.accept(e.value);
2899 if ((p = e.right) != null) {
2900 while ((pl = p.left) != null)
2901 p = pl;
2902 }
2903 else {
2904 while ((p = e.parent) != null && e == p.right)
2905 e = p;
2906 }
2907 } while ((e = p) != null && e != f);
2908 if (tree.modCount != expectedModCount)
2909 throw new ConcurrentModificationException();
2910 }
2911 }
2912
2913 public boolean tryAdvance(Consumer<? super V> action) {
2914 TreeMap.Entry<K,V> e;
2915 if (action == null)
2916 throw new NullPointerException();
2917 if (est < 0)
2918 getEstimate(); // force initialization
2919 if ((e = current) == null || e == fence)
2920 return false;
2921 current = successor(e);
2922 action.accept(e.value);
2923 if (tree.modCount != expectedModCount)
2924 throw new ConcurrentModificationException();
2925 return true;
2926 }
2927
2928 public int characteristics() {
2929 return (side == 0 ? Spliterator.SIZED : 0) | Spliterator.ORDERED;
2930 }
2931 }
2932
2933 static final class EntrySpliterator<K,V>
2934 extends TreeMapSpliterator<K,V>
2935 implements Spliterator<Map.Entry<K,V>> {
2936 EntrySpliterator(TreeMap<K,V> tree,
2937 TreeMap.Entry<K,V> origin, TreeMap.Entry<K,V> fence,
2938 int side, int est, int expectedModCount) {
2939 super(tree, origin, fence, side, est, expectedModCount);
2940 }
2941
2942 public EntrySpliterator<K,V> trySplit() {
2943 if (est < 0)
2944 getEstimate(); // force initialization
2945 int d = side;
2946 TreeMap.Entry<K,V> e = current, f = fence,
2947 s = ((e == null || e == f) ? null : // empty
2948 (d == 0) ? tree.root : // was top
2949 (d > 0) ? e.right : // was right
2950 (d < 0 && f != null) ? f.left : // was left
2951 null);
2952 if (s != null && s != e && s != f &&
2953 tree.compare(e.key, s.key) < 0) { // e not already past s
2954 side = 1;
2955 return new EntrySpliterator<>
2956 (tree, e, current = s, -1, est >>>= 1, expectedModCount);
2957 }
2958 return null;
2959 }
2960
2961 public void forEachRemaining(Consumer<? super Map.Entry<K, V>> action) {
2962 if (action == null)
2963 throw new NullPointerException();
2964 if (est < 0)
2965 getEstimate(); // force initialization
2966 TreeMap.Entry<K,V> f = fence, e, p, pl;
2967 if ((e = current) != null && e != f) {
2968 current = f; // exhaust
2969 do {
2970 action.accept(e);
2971 if ((p = e.right) != null) {
2972 while ((pl = p.left) != null)
2973 p = pl;
2974 }
2975 else {
2976 while ((p = e.parent) != null && e == p.right)
2977 e = p;
2978 }
2979 } while ((e = p) != null && e != f);
2980 if (tree.modCount != expectedModCount)
2981 throw new ConcurrentModificationException();
2982 }
2983 }
2984
2985 public boolean tryAdvance(Consumer<? super Map.Entry<K,V>> action) {
2986 TreeMap.Entry<K,V> e;
2987 if (action == null)
2988 throw new NullPointerException();
2989 if (est < 0)
2990 getEstimate(); // force initialization
2991 if ((e = current) == null || e == fence)
2992 return false;
2993 current = successor(e);
2994 action.accept(e);
2995 if (tree.modCount != expectedModCount)
2996 throw new ConcurrentModificationException();
2997 return true;
2998 }
2999
3000 public int characteristics() {
3001 return (side == 0 ? Spliterator.SIZED : 0) |
3002 Spliterator.DISTINCT | Spliterator.SORTED | Spliterator.ORDERED;
3003 }
3004
3005 @Override
3006 public Comparator<Map.Entry<K, V>> getComparator() {
3007 // Adapt or create a key-based comparator
3008 if (tree.comparator != null) {
3009 return Map.Entry.comparingByKey(tree.comparator);
3010 }
3011 else {
3012 return (Comparator<Map.Entry<K, V>> & Serializable) (e1, e2) -> {
3013 @SuppressWarnings("unchecked")
3014 Comparable<? super K> k1 = (Comparable<? super K>) e1.getKey();
3015 return k1.compareTo(e2.getKey());
3016 };
3017 }
3018 }
3019 }
3020 }