1 /*
2 * Copyright (c) 1997, 2024, 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 org.openjdk.bench.valhalla.sandbox.corelibs.corelibs.mapprotos;
27
28 import java.io.IOException;
29 import java.io.InvalidObjectException;
30 import java.io.PrintStream;
31 import java.io.Serializable;
32 import java.lang.reflect.InvocationTargetException;
33 import java.lang.reflect.Method;
34 import java.lang.reflect.ParameterizedType;
35 import java.lang.reflect.Type;
36 import java.util.AbstractCollection;
37 //import java.util.AbstractMap;
38 import java.util.AbstractSet;
39 import java.util.Arrays;
40 import java.util.Collection;
41 import java.util.Collections;
42 import java.util.ConcurrentModificationException;
43 import java.util.Hashtable;
44 import java.util.Iterator;
45 import java.util.Map;
46 import java.util.Objects;
47 import java.util.Optional;
48 import java.util.TreeMap;
49 import java.util.NoSuchElementException;
50 import java.util.Set;
51 import java.util.function.BiConsumer;
52 import java.util.function.BiFunction;
53 import java.util.function.Consumer;
54 import java.util.function.Function;
55
56 /**
57 * Hash map implementation that uses inline class entries in the initial table
58 * and maintains a link list of separate Node entries for key/value pairs
59 * that have the same hash value. The handling of the link list is the same
60 * as the original java.util.HashMap.
61 * The primary entry array is larger than in HashMap due to the inline storage
62 * of the entries but since it replaces the separate Node instance for the first
63 * Node, the overall memory usage is less for a reasonably full table.
64 * The TreeNode organization is not yet implemented.
65 * <p>
66 * Hash table based implementation of the {@code Map} interface. This
67 * implementation provides all of the optional map operations, and permits
68 * {@code null} values and the {@code null} key. (The {@code HashMap}
69 * class is roughly equivalent to {@code Hashtable}, except that it is
70 * unsynchronized and permits nulls.) This class makes no guarantees as to
71 * the order of the map; in particular, it does not guarantee that the order
72 * will remain constant over time.
73 *
74 * <p>This implementation provides constant-time performance for the basic
75 * operations ({@code get} and {@code put}), assuming the hash function
76 * disperses the elements properly among the buckets. Iteration over
77 * collection views requires time proportional to the "capacity" of the
78 * {@code HashMap} instance (the number of buckets) plus its size (the number
79 * of key-value mappings). Thus, it's very important not to set the initial
80 * capacity too high (or the load factor too low) if iteration performance is
81 * important.
82 *
83 * <p>An instance of {@code HashMap} has two parameters that affect its
84 * performance: <i>initial capacity</i> and <i>load factor</i>. The
85 * <i>capacity</i> is the number of buckets in the hash table, and the initial
86 * capacity is simply the capacity at the time the hash table is created. The
87 * <i>load factor</i> is a measure of how full the hash table is allowed to
88 * get before its capacity is automatically increased. When the number of
89 * entries in the hash table exceeds the product of the load factor and the
90 * current capacity, the hash table is <i>rehashed</i> (that is, internal data
91 * structures are rebuilt) so that the hash table has approximately twice the
92 * number of buckets.
93 *
94 * <p>As a general rule, the default load factor (.75) offers a good
95 * tradeoff between time and space costs. Higher values decrease the
96 * space overhead but increase the lookup cost (reflected in most of
97 * the operations of the {@code HashMap} class, including
98 * {@code get} and {@code put}). The expected number of entries in
99 * the map and its load factor should be taken into account when
100 * setting its initial capacity, so as to minimize the number of
101 * rehash operations. If the initial capacity is greater than the
102 * maximum number of entries divided by the load factor, no rehash
103 * operations will ever occur.
104 *
105 * <p>If many mappings are to be stored in a {@code HashMap}
106 * instance, creating it with a sufficiently large capacity will allow
107 * the mappings to be stored more efficiently than letting it perform
108 * automatic rehashing as needed to grow the table. Note that using
109 * many keys with the same {@code hashCode()} is a sure way to slow
110 * down performance of any hash table. To ameliorate impact, when keys
111 * are {@link Comparable}, this class may use comparison order among
112 * keys to help break ties.
113 *
114 * <p><strong>Note that this implementation is not synchronized.</strong>
115 * If multiple threads access a hash map concurrently, and at least one of
116 * the threads modifies the map structurally, it <i>must</i> be
117 * synchronized externally. (A structural modification is any operation
118 * that adds or deletes one or more mappings; merely changing the value
119 * associated with a key that an instance already contains is not a
120 * structural modification.) This is typically accomplished by
121 * synchronizing on some object that naturally encapsulates the map.
122 *
123 * If no such object exists, the map should be "wrapped" using the
124 * {@link Collections#synchronizedMap Collections.synchronizedMap}
125 * method. This is best done at creation time, to prevent accidental
126 * unsynchronized access to the map:<pre>
127 * Map m = Collections.synchronizedMap(new HashMap(...));</pre>
128 *
129 * <p>The iterators returned by all of this class's "collection view methods"
130 * are <i>fail-fast</i>: if the map is structurally modified at any time after
131 * the iterator is created, in any way except through the iterator's own
132 * {@code remove} method, the iterator will throw a
133 * {@link ConcurrentModificationException}. Thus, in the face of concurrent
134 * modification, the iterator fails quickly and cleanly, rather than risking
135 * arbitrary, non-deterministic behavior at an undetermined time in the
136 * future.
137 *
138 * <p>Note that the fail-fast behavior of an iterator cannot be guaranteed
139 * as it is, generally speaking, impossible to make any hard guarantees in the
140 * presence of unsynchronized concurrent modification. Fail-fast iterators
141 * throw {@code ConcurrentModificationException} on a best-effort basis.
142 * Therefore, it would be wrong to write a program that depended on this
143 * exception for its correctness: <i>the fail-fast behavior of iterators
144 * should be used only to detect bugs.</i>
145 *
146 * <p>This class is a member of the
147 * <a href="{@docRoot}/java.base/java/util/package-summary.html#CollectionsFramework">
148 * Java Collections Framework</a>.
149 *
150 * @param <K> the type of keys maintained by this map
151 * @param <V> the type of mapped values
152 *
153 * @author Doug Lea
154 * @author Josh Bloch
155 * @author Arthur van Hoff
156 * @author Neal Gafter
157 * @see Object#hashCode()
158 * @see Collection
159 * @see Map
160 * @see TreeMap
161 * @see Hashtable
162 * @since 1.2
163 */
164 public class XHashMap<K,V> extends XAbstractMap<K,V>
165 implements Map<K,V>, Cloneable, Serializable {
166
167 private static final long serialVersionUID = 362498820763181265L;
168
169 /*
170 * Implementation notes.
171 *
172 * This map usually acts as a binned (bucketed) hash table, but
173 * when bins get too large, they are transformed into bins of
174 * TreeNodes, each structured similarly to those in
175 * java.util.TreeMap. Most methods try to use normal bins, but
176 * relay to TreeNode methods when applicable (simply by checking
177 * instanceof a node). Bins of TreeNodes may be traversed and
178 * used like any others, but additionally support faster lookup
179 * when overpopulated. However, since the vast majority of bins in
180 * normal use are not overpopulated, checking for existence of
181 * tree bins may be delayed in the course of table methods.
182 *
183 * Tree bins (i.e., bins whose elements are all TreeNodes) are
184 * ordered primarily by hashCode, but in the case of ties, if two
185 * elements are of the same "class C implements Comparable<C>",
186 * type then their compareTo method is used for ordering. (We
187 * conservatively check generic types via reflection to validate
188 * this -- see method comparableClassFor). The added complexity
189 * of tree bins is worthwhile in providing worst-case O(log n)
190 * operations when keys either have distinct hashes or are
191 * orderable, Thus, performance degrades gracefully under
192 * accidental or malicious usages in which hashCode() methods
193 * return values that are poorly distributed, as well as those in
194 * which many keys share a hashCode, so long as they are also
195 * Comparable. (If neither of these apply, we may waste about a
196 * factor of two in time and space compared to taking no
197 * precautions. But the only known cases stem from poor user
198 * programming practices that are already so slow that this makes
199 * little difference.)
200 *
201 * Because TreeNodes are about twice the size of regular nodes, we
202 * use them only when bins contain enough nodes to warrant use
203 * (see TREEIFY_THRESHOLD). And when they become too small (due to
204 * removal or resizing) they are converted back to plain bins. In
205 * usages with well-distributed user hashCodes, tree bins are
206 * rarely used. Ideally, under random hashCodes, the frequency of
207 * nodes in bins follows a Poisson distribution
208 * (http://en.wikipedia.org/wiki/Poisson_distribution) with a
209 * parameter of about 0.5 on average for the default resizing
210 * threshold of 0.75, although with a large variance because of
211 * resizing granularity. Ignoring variance, the expected
212 * occurrences of list size k are (exp(-0.5) * pow(0.5, k) /
213 * factorial(k)). The first values are:
214 *
215 * 0: 0.60653066
216 * 1: 0.30326533
217 * 2: 0.07581633
218 * 3: 0.01263606
219 * 4: 0.00157952
220 * 5: 0.00015795
221 * 6: 0.00001316
222 * 7: 0.00000094
223 * 8: 0.00000006
224 * more: less than 1 in ten million
225 *
226 * The root of a tree bin is normally its first node. However,
227 * sometimes (currently only upon Iterator.remove), the root might
228 * be elsewhere, but can be recovered following parent links
229 * (method TreeNode.root()).
230 *
231 * All applicable internal methods accept a hash code as an
232 * argument (as normally supplied from a public method), allowing
233 * them to call each other without recomputing user hashCodes.
234 * Most internal methods also accept a "tab" argument, that is
235 * normally the current table, but may be a new or old one when
236 * resizing or converting.
237 *
238 * When bin lists are treeified, split, or untreeified, we keep
239 * them in the same relative access/traversal order (i.e., field
240 * Node.next) to better preserve locality, and to slightly
241 * simplify handling of splits and traversals that invoke
242 * iterator.remove. When using comparators on insertion, to keep a
243 * total ordering (or as close as is required here) across
244 * rebalancings, we compare classes and identityHashCodes as
245 * tie-breakers.
246 *
247 * The use and transitions among plain vs tree modes is
248 * complicated by the existence of subclass LinkedHashMap. See
249 * below for hook methods defined to be invoked upon insertion,
250 * removal and access that allow LinkedHashMap internals to
251 * otherwise remain independent of these mechanics. (This also
252 * requires that a map instance be passed to some utility methods
253 * that may create new nodes.)
254 *
255 * The concurrent-programming-like SSA-based coding style helps
256 * avoid aliasing errors amid all of the twisty pointer operations.
257 */
258
259 /**
260 * The default initial capacity - MUST be a power of two.
261 */
262 static final int DEFAULT_INITIAL_CAPACITY = 1 << 4; // aka 16
263
264 /**
265 * The maximum capacity, used if a higher value is implicitly specified
266 * by either of the constructors with arguments.
267 * MUST be a power of two <= 1<<30.
268 */
269 static final int MAXIMUM_CAPACITY = 1 << 30;
270
271 /**
272 * The load factor used when none specified in constructor.
273 */
274 static final float DEFAULT_LOAD_FACTOR = 0.75f;
275
276 /**
277 * The bin count threshold for using a tree rather than list for a
278 * bin. Bins are converted to trees when adding an element to a
279 * bin with at least this many nodes. The value must be greater
280 * than 2 and should be at least 8 to mesh with assumptions in
281 * tree removal about conversion back to plain bins upon
282 * shrinkage.
283 */
284 static final int TREEIFY_THRESHOLD = 8;
285
286 /**
287 * The bin count threshold for untreeifying a (split) bin during a
288 * resize operation. Should be less than TREEIFY_THRESHOLD, and at
289 * most 6 to mesh with shrinkage detection under removal.
290 */
291 static final int UNTREEIFY_THRESHOLD = 6;
292
293 /**
294 * The smallest table capacity for which bins may be treeified.
295 * (Otherwise the table is resized if too many nodes in a bin.)
296 * Should be at least 4 * TREEIFY_THRESHOLD to avoid conflicts
297 * between resizing and treeification thresholds.
298 */
299 static final int MIN_TREEIFY_CAPACITY = 64;
300
301 private XNode<K,V> emptyXNode() {
302 return new XNode();
303 }
304 /**
305 * Basic hash bin node, used for most entries. (See below for
306 * TreeNode subclass, and in LinkedHashMap for its Entry subclass.)
307 */
308 static value class XNode<K,V> implements Map.Entry<K,V> {
309 final int hash;
310 final K key;
311 V value;
312 Node<K,V> next;
313
314 XNode() {
315 this.hash = 0;
316 this.key = null;
317 this.value = null;
318 this.next = null;
319 }
320
321 XNode(int hash, K key, V value, Node<K,V> next) {
322 this.hash = hash;
323 this.key = key;
324 this.value = value;
325 this.next = next;
326 }
327
328 boolean isEmpty() {
329 return hash == 0 && key == null && value == null;
330 }
331 public final K getKey() { return key; }
332 public final V getValue() { return value; }
333 public final String toString() { return key + "=" + value; }
334
335 public final int hashCode() {
336 return Objects.hashCode(key) ^ Objects.hashCode(value);
337 }
338
339 public final V setValue(V newValue) {
340 throw new IllegalStateException("XNode cannot set a value");
341 // V oldValue = value;
342 // value = newValue;
343 // return oldValue;
344 }
345
346 public final boolean equals(Object o) {
347 if (o instanceof Map.Entry) {
348 Map.Entry<?,?> e = (Map.Entry<?,?>)o;
349 if (Objects.equals(key, e.getKey()) &&
350 Objects.equals(value, e.getValue()))
351 return true;
352 }
353 return false;
354 }
355 }
356
357 /**
358 * Basic hash bin node, used for overflow entries. (See below for
359 * TreeNode subclass, and in LinkedHashMap for its Entry subclass.)
360 */
361 static class Node<K,V> implements Map.Entry<K,V> {
362 final int hash;
363 final K key;
364 V value;
365 Node<K,V> next;
366
367 Node(int hash, K key, V value, Node<K,V> next) {
368 this.hash = hash;
369 this.key = key;
370 this.value = value;
371 this.next = next;
372 }
373
374 public final K getKey() { return key; }
375 public final V getValue() { return value; }
376 public final String toString() { return key + "=" + value; }
377 public final int hashCode() {
378 return Objects.hashCode(key) ^ Objects.hashCode(value);
379 }
380
381 public final V setValue(V newValue) {
382 V oldValue = value;
383 value = newValue;
384 return oldValue;
385 }
386
387 public final boolean equals(Object o) {
388 if (o == this)
389 return true;
390 if (o instanceof Map.Entry) {
391 Map.Entry<?,?> e = (Map.Entry<?,?>)o;
392 if (Objects.equals(key, e.getKey()) &&
393 Objects.equals(value, e.getValue()))
394 return true;
395 }
396 return false;
397 }
398 }
399
400 value class XNodeWrapper implements Map.Entry<K,V> {
401 int index;
402
403 XNodeWrapper(int index) {
404 this.index = index;
405 }
406
407 public K getKey() {
408 XNode<K,V> e = table[index];
409 return e.isEmpty() ? null : e.key;
410 }
411
412 public V getValue() {
413 XNode<K,V> e = table[index];
414 return e.isEmpty() ? null : e.value;
415 }
416
417 /**
418 * Replaces the value corresponding to this entry with the specified
419 * value (optional operation). (Writes through to the map.) The
420 * behavior of this call is undefined if the mapping has already been
421 * removed from the map (by the iterator's {@code remove} operation).
422 *
423 * @param value new value to be stored in this entry
424 * @return old value corresponding to the entry
425 * @throws UnsupportedOperationException if the {@code put} operation
426 * is not supported by the backing map
427 * @throws ClassCastException if the class of the specified value
428 * prevents it from being stored in the backing map
429 * @throws NullPointerException if the backing map does not permit
430 * null values, and the specified value is null
431 * @throws IllegalArgumentException if some property of this value
432 * prevents it from being stored in the backing map
433 * @throws IllegalStateException implementations may, but are not
434 * required to, throw this exception if the entry has been
435 * removed from the backing map.
436 */
437 public V setValue(V value) {
438 XNode<K,V> e = table[index];
439 assert !e.isEmpty();
440 table[index] = new XNode(e.hash, e.key, value, e.next);
441 return e.value;
442 }
443 }
444 /* ---------------- Static utilities -------------- */
445
446 /**
447 * Computes key.hashCode() and spreads (XORs) higher bits of hash
448 * to lower. Because the table uses power-of-two masking, sets of
449 * hashes that vary only in bits above the current mask will
450 * always collide. (Among known examples are sets of Float keys
451 * holding consecutive whole numbers in small tables.) So we
452 * apply a transform that spreads the impact of higher bits
453 * downward. There is a tradeoff between speed, utility, and
454 * quality of bit-spreading. Because many common sets of hashes
455 * are already reasonably distributed (so don't benefit from
456 * spreading), and because we use trees to handle large sets of
457 * collisions in bins, we just XOR some shifted bits in the
458 * cheapest possible way to reduce systematic lossage, as well as
459 * to incorporate impact of the highest bits that would otherwise
460 * never be used in index calculations because of table bounds.
461 */
462 static final int hash(Object key) {
463 int h;
464 return (key == null) ? 0 : (h = key.hashCode()) ^ (h >>> 16);
465 }
466
467 /**
468 * Returns x's Class if it is of the form "class C implements
469 * Comparable<C>", else null.
470 */
471 static Class<?> comparableClassFor(Object x) {
472 if (x instanceof Comparable) {
473 Class<?> c; Type[] ts, as; ParameterizedType p;
474 if ((c = x.getClass()) == String.class) // bypass checks
475 return c;
476 if ((ts = c.getGenericInterfaces()) != null) {
477 for (Type t : ts) {
478 if ((t instanceof ParameterizedType) &&
479 ((p = (ParameterizedType) t).getRawType() ==
480 Comparable.class) &&
481 (as = p.getActualTypeArguments()) != null &&
482 as.length == 1 && as[0] == c) // type arg is c
483 return c;
484 }
485 }
486 }
487 return null;
488 }
489
490 /**
491 * Returns k.compareTo(x) if x matches kc (k's screened comparable
492 * class), else 0.
493 */
494 @SuppressWarnings({"rawtypes","unchecked"}) // for cast to Comparable
495 static int compareComparables(Class<?> kc, Object k, Object x) {
496 return (x == null || x.getClass() != kc ? 0 :
497 ((Comparable)k).compareTo(x));
498 }
499
500 /**
501 * Returns a power of two size for the given target capacity.
502 */
503 static final int tableSizeFor(int cap) {
504 int n = -1 >>> Integer.numberOfLeadingZeros(cap - 1);
505 return (n < 0) ? 1 : (n >= MAXIMUM_CAPACITY) ? MAXIMUM_CAPACITY : n + 1;
506 }
507
508 /* ---------------- Fields -------------- */
509
510 /**
511 * The table, initialized on first use, and resized as
512 * necessary. When allocated, length is always a power of two.
513 * (We also tolerate length zero in some operations to allow
514 * bootstrapping mechanics that are currently not needed.)
515 */
516 transient XNode<K,V>[] table;
517
518 /**
519 * Holds cached entrySet(). Note that AbstractMap fields are used
520 * for keySet() and values().
521 */
522 transient Set<Map.Entry<K,V>> entrySet;
523
524 /**
525 * The number of key-value mappings contained in this map.
526 */
527 transient int size;
528
529 /**
530 * The number of times this HashMap has been structurally modified
531 * Structural modifications are those that change the number of mappings in
532 * the HashMap or otherwise modify its internal structure (e.g.,
533 * rehash). This field is used to make iterators on Collection-views of
534 * the HashMap fail-fast. (See ConcurrentModificationException).
535 */
536 transient int modCount;
537
538 /**
539 * The next size value at which to resize (capacity * load factor).
540 *
541 * @serial
542 */
543 // (The javadoc description is true upon serialization.
544 // Additionally, if the table array has not been allocated, this
545 // field holds the initial array capacity, or zero signifying
546 // DEFAULT_INITIAL_CAPACITY.)
547 int threshold;
548
549 /**
550 * The load factor for the hash table.
551 *
552 * @serial
553 */
554 final float loadFactor;
555
556 /* ---------------- Public operations -------------- */
557
558 /**
559 * Constructs an empty {@code HashMap} with the specified initial
560 * capacity and load factor.
561 *
562 * @param initialCapacity the initial capacity
563 * @param loadFactor the load factor
564 * @throws IllegalArgumentException if the initial capacity is negative
565 * or the load factor is nonpositive
566 */
567 public XHashMap(int initialCapacity, float loadFactor) {
568 if (initialCapacity < 0)
569 throw new IllegalArgumentException("Illegal initial capacity: " +
570 initialCapacity);
571 if (initialCapacity > MAXIMUM_CAPACITY)
572 initialCapacity = MAXIMUM_CAPACITY;
573 if (loadFactor <= 0 || Float.isNaN(loadFactor))
574 throw new IllegalArgumentException("Illegal load factor: " +
575 loadFactor);
576 this.loadFactor = loadFactor;
577 this.threshold = tableSizeFor(initialCapacity);
578 }
579
580 /**
581 * Constructs an empty {@code HashMap} with the specified initial
582 * capacity and the default load factor (0.75).
583 *
584 * @param initialCapacity the initial capacity.
585 * @throws IllegalArgumentException if the initial capacity is negative.
586 */
587 public XHashMap(int initialCapacity) {
588 this(initialCapacity, DEFAULT_LOAD_FACTOR);
589 }
590
591 /**
592 * Constructs an empty {@code HashMap} with the default initial capacity
593 * (16) and the default load factor (0.75).
594 */
595 public XHashMap() {
596 this.loadFactor = DEFAULT_LOAD_FACTOR; // all other fields defaulted
597 }
598
599 /**
600 * Constructs a new {@code HashMap} with the same mappings as the
601 * specified {@code Map}. The {@code HashMap} is created with
602 * default load factor (0.75) and an initial capacity sufficient to
603 * hold the mappings in the specified {@code Map}.
604 *
605 * @param m the map whose mappings are to be placed in this map
606 * @throws NullPointerException if the specified map is null
607 */
608 public XHashMap(Map<? extends K, ? extends V> m) {
609 this.loadFactor = DEFAULT_LOAD_FACTOR;
610 putMapEntries(m, false);
611 }
612
613 /**
614 * Implements Map.putAll and Map constructor.
615 *
616 * @param m the map
617 * @param evict false when initially constructing this map, else true.
618 */
619 final void putMapEntries(Map<? extends K, ? extends V> m, boolean evict) {
620 int s = m.size();
621 if (s > 0) {
622 if (table == null) { // pre-size
623 float ft = ((float)s / loadFactor) + 1.0F;
624 int t = ((ft < (float)MAXIMUM_CAPACITY) ?
625 (int)ft : MAXIMUM_CAPACITY);
626 if (t > threshold)
627 threshold = tableSizeFor(t);
628 } else {
629 // Because of linked-list bucket constraints, we cannot
630 // expand all at once, but can reduce total resize
631 // effort by repeated doubling now vs later
632 while (s > threshold && table.length < MAXIMUM_CAPACITY)
633 resize();
634 }
635
636 for (Map.Entry<? extends K, ? extends V> e : m.entrySet()) {
637 K key = e.getKey();
638 V value = e.getValue();
639 putVal(hash(key), key, value, false, evict);
640 }
641 }
642 }
643
644 /**
645 * Returns the number of key-value mappings in this map.
646 *
647 * @return the number of key-value mappings in this map
648 */
649 public int size() {
650 return size;
651 }
652
653 /**
654 * Returns {@code true} if this map contains no key-value mappings.
655 *
656 * @return {@code true} if this map contains no key-value mappings
657 */
658 public boolean isEmpty() {
659 return size == 0;
660 }
661
662 /**
663 * Returns the value to which the specified key is mapped,
664 * or {@code null} if this map contains no mapping for the key.
665 *
666 * <p>More formally, if this map contains a mapping from a key
667 * {@code k} to a value {@code v} such that {@code (key==null ? k==null :
668 * key.equals(k))}, then this method returns {@code v}; otherwise
669 * it returns {@code null}. (There can be at most one such mapping.)
670 *
671 * <p>A return value of {@code null} does not <i>necessarily</i>
672 * indicate that the map contains no mapping for the key; it's also
673 * possible that the map explicitly maps the key to {@code null}.
674 * The {@link #containsKey containsKey} operation may be used to
675 * distinguish these two cases.
676 *
677 * @see #put(Object, Object)
678 */
679 public V get(Object key) {
680 int hash = hash(key);
681 Node<K,V> e;
682 XNode<K,V> n = getXNode(hash, key);
683 return (!n.isEmpty()) ? n.value
684 : (e = getNode(hash, key)) == null ? null : e.value;
685 }
686
687 /**
688 * Implements Map.get and related methods.
689 *
690 * @param hash hash for key
691 * @param key the key
692 * @return the node, or emptyXNode() if not at top level.
693 */
694 final XNode<K,V> getXNode(int hash, Object key) {
695 XNode<K, V>[] tab;
696 XNode<K, V> first;
697 int n;
698 K k;
699 if ((tab = table) != null && (n = tab.length) > 0 &&
700 !(first = tab[(n - 1) & hash]).isEmpty()) {
701 if (first.hash == hash && // always check first node
702 ((k = first.key) == key || (key != null && key.equals(k))))
703 return first;
704 }
705 return emptyXNode();
706 }
707
708 /**
709 * Implements Map.get and related methods when the key is not found in the primary entry.
710 *
711 * @param hash hash for key
712 * @param key the key
713 * @return the node, or null if none
714 */
715 final Node<K,V> getNode(int hash, Object key) {
716 XNode<K,V>[] tab; XNode<K,V> first; Node<K,V> e; int n; K k;
717 if ((tab = table) != null && (n = tab.length) > 0 &&
718 !(first = tab[(n - 1) & hash]).isEmpty()) {
719 if ((e = first.next) != null) {
720 if (e instanceof TreeNode)
721 return ((TreeNode<K,V>)e).getTreeNode(hash, key);
722 do {
723 if (e.hash == hash &&
724 ((k = e.key) == key || (key != null && key.equals(k))))
725 return e;
726 } while ((e = e.next) != null);
727 }
728 }
729 return null;
730 }
731
732 /**
733 * Returns {@code true} if this map contains a mapping for the
734 * specified key.
735 *
736 * @param key The key whose presence in this map is to be tested
737 * @return {@code true} if this map contains a mapping for the specified
738 * key.
739 */
740 public boolean containsKey(Object key) {
741 int hash = hash(key);
742 Node<K,V> e;
743 XNode<K,V> n = getXNode(hash, key);
744 return !n.isEmpty() || (e = getNode(hash, key)) != null;
745 }
746
747 /**
748 * Associates the specified value with the specified key in this map.
749 * If the map previously contained a mapping for the key, the old
750 * value is replaced.
751 *
752 * @param key key with which the specified value is to be associated
753 * @param value value to be associated with the specified key
754 * @return the previous value associated with {@code key}, or
755 * {@code null} if there was no mapping for {@code key}.
756 * (A {@code null} return can also indicate that the map
757 * previously associated {@code null} with {@code key}.)
758 */
759 public V put(K key, V value) {
760 return putVal(hash(key), key, value, false, true);
761 }
762
763 /**
764 * Implements Map.put and related methods.
765 *
766 * @param hash hash for key
767 * @param key the key
768 * @param value the value to put
769 * @param onlyIfAbsent if true, don't change existing value
770 * @param evict if false, the table is in creation mode.
771 * @return previous value, or null if none
772 */
773 final V putVal(int hash, K key, V value, boolean onlyIfAbsent,
774 boolean evict) {
775 XNode<K,V>[] tab; XNode<K,V> tp; int n, i;
776 if ((tab = table) == null || (n = tab.length) == 0)
777 n = (tab = resize()).length;
778 if ((tp = tab[i = (n - 1) & hash]).isEmpty()) {
779 tab[i] = new XNode(hash, key, value, null);
780 } else {
781 Node<K,V> e; K k;
782 if (tp.hash == hash &&
783 ((k = tp.key) == key || (key != null && key.equals(k)))) {
784 if (!onlyIfAbsent || tp.value == null) {
785 tab[i] = new XNode(hash, k, value, tp.next);
786 }
787 return tp.value;
788 } else if ((e = tp.next) == null) {
789 Node<K,V> x = newNode(hash, key, value, null);
790 tab[i] = new XNode(tp.hash, tp.key, tp.value, x);
791 } else if (e instanceof TreeNode) {
792 e = ((TreeNode<K, V>) e).putTreeVal(this, tab, hash, key, value);
793 } else {
794 for (int binCount = 0; ; ++binCount) {
795 if (e.hash == hash &&
796 ((k = e.key) == key || (key != null && key.equals(k))))
797 break;
798 Node<K,V> p = e;
799 if ((e = p.next) == null) {
800 p.next = newNode(hash, key, value, null);
801 if (binCount >= TREEIFY_THRESHOLD - 1) // -1 for 1st
802 treeifyBin(tab, hash);
803 break;
804 }
805 }
806 }
807 if (e != null) { // existing mapping for key
808 V oldValue = e.value;
809 if (!onlyIfAbsent || oldValue == null)
810 e.value = value;
811 return oldValue;
812 }
813 }
814
815 ++modCount;
816 if (++size > threshold)
817 resize();
818 return null;
819 }
820
821 /**
822 * Initializes or doubles table size. If null, allocates in
823 * accord with initial capacity target held in field threshold.
824 * Otherwise, because we are using power-of-two expansion, the
825 * elements from each bin must either stay at same index, or move
826 * with a power of two offset in the new table.
827 *
828 * @return the table
829 */
830 final XNode<K,V>[] resize() {
831 XNode<K,V>[] oldTab = table;
832 int oldCap = (oldTab == null) ? 0 : oldTab.length;
833 int oldThr = threshold;
834 int newCap, newThr = 0;
835 if (oldCap > 0) {
836 if (oldCap >= MAXIMUM_CAPACITY) {
837 threshold = Integer.MAX_VALUE;
838 return oldTab;
839 }
840 else if ((newCap = oldCap << 1) < MAXIMUM_CAPACITY &&
841 oldCap >= DEFAULT_INITIAL_CAPACITY)
842 newThr = oldThr << 1; // double threshold
843 }
844 else if (oldThr > 0) // initial capacity was placed in threshold
845 newCap = oldThr;
846 else { // zero initial threshold signifies using defaults
847 newCap = DEFAULT_INITIAL_CAPACITY;
848 newThr = (int)(DEFAULT_LOAD_FACTOR * DEFAULT_INITIAL_CAPACITY);
849 }
850 if (newThr == 0) {
851 float ft = (float)newCap * loadFactor;
852 newThr = (newCap < MAXIMUM_CAPACITY && ft < (float)MAXIMUM_CAPACITY ?
853 (int)ft : Integer.MAX_VALUE);
854 }
855 threshold = newThr;
856 @SuppressWarnings({"rawtypes","unchecked"})
857 XNode<K,V>[] newTab = (XNode<K,V>[])new XNode[newCap];
858 table = newTab;
859 if (oldTab != null) {
860 for (int j = 0; j < oldCap; ++j) {
861 XNode<K,V> x;
862 Node<K,V> e;
863 if (!(x = oldTab[j]).isEmpty()) {
864 oldTab[j] = emptyXNode();
865 if ((e = x.next) == null)
866 newTab[x.hash & (newCap - 1)] = new XNode(x.hash, x.key, x.value, null);
867 else if (e instanceof TreeNode)
868 ((TreeNode<K,V>)e).split(this, newTab, j, oldCap);
869 else { // preserve order
870 Node<K,V> loHead = null, loTail = null;
871 Node<K,V> hiHead = null, hiTail = null;
872 Node<K,V> next;
873 do {
874 next = e.next;
875 if ((e.hash & oldCap) == 0) {
876 if (loTail == null)
877 loHead = e;
878 else
879 loTail.next = e;
880 loTail = e;
881 }
882 else {
883 if (hiTail == null)
884 hiHead = e;
885 else
886 hiTail.next = e;
887 hiTail = e;
888 }
889 } while ((e = next) != null);
890 if (loTail != null)
891 loTail.next = null;
892 if (hiTail != null)
893 hiTail.next = null;
894
895 newTab[j] = (j == (x.hash & (newCap - 1)))
896 ? new XNode(x.hash, x.key, x.value, loHead)
897 : ((loHead != null)
898 ? new XNode(loHead.hash, loHead.key, loHead.value, loHead.next) :
899 emptyXNode());
900
901 newTab[j + oldCap] = ((j + oldCap) == (x.hash & (newCap - 1)))
902 ? new XNode(x.hash, x.key, x.value, hiHead)
903 : ((hiHead != null)
904 ? new XNode(hiHead.hash, hiHead.key, hiHead.value, hiHead.next) :
905 emptyXNode());
906 }
907 }
908 }
909 }
910 return newTab;
911 }
912
913 /**
914 * Replaces all linked nodes in bin at index for given hash unless
915 * table is too small, in which case resizes instead.
916 */
917 final void treeifyBin(XNode<K,V>[] tab, int hash) {
918 // int n, index; Node<K,V> e;
919 // if (tab == null || (n = tab.length) < MIN_TREEIFY_CAPACITY)
920 // resize();
921 // else if ((e = tab[index = (n - 1) & hash]) != null) {
922 // TreeNode<K,V> hd = null, tl = null;
923 // do {
924 // TreeNode<K,V> p = replacementTreeNode(e, null);
925 // if (tl == null)
926 // hd = p;
927 // else {
928 // p.prev = tl;
929 // tl.next = p;
930 // }
931 // tl = p;
932 // } while ((e = e.next) != null);
933 // if ((tab[index] = hd) != null)
934 // hd.treeify(tab);
935 // }
936 }
937
938 /**
939 * Copies all of the mappings from the specified map to this map.
940 * These mappings will replace any mappings that this map had for
941 * any of the keys currently in the specified map.
942 *
943 * @param m mappings to be stored in this map
944 * @throws NullPointerException if the specified map is null
945 */
946 public void putAll(Map<? extends K, ? extends V> m) {
947 putMapEntries(m, true);
948 }
949
950 /**
951 * Removes the mapping for the specified key from this map if present.
952 *
953 * @param key key whose mapping is to be removed from the map
954 * @return the previous value associated with {@code key}, or
955 * {@code null} if there was no mapping for {@code key}.
956 * (A {@code null} return can also indicate that the map
957 * previously associated {@code null} with {@code key}.)
958 */
959 public V remove(Object key) {
960 Optional<V> o = removeNode(hash(key), key, null, false, true);
961 return o.orElse(null);
962 }
963
964 /**
965 * Implements Map.remove and related methods.
966 *
967 * @param hash hash for key
968 * @param key the key
969 * @param value the value to match if matchValue, else ignored
970 * @param matchValue if true only remove if value is equal
971 * @param movable if false do not move other nodes while removing
972 * @return the node, or null if none
973 */
974 final Optional<V> removeNode(int hash, Object key, Object value,
975 boolean matchValue, boolean movable) {
976 XNode<K,V>[] tab; XNode<K,V> te; int n, index;
977 if ((tab = table) != null && (n = tab.length) > 0 &&
978 !(te = tab[index = (n - 1) & hash]).isEmpty()) {
979 Node<K,V> node = null, e; K k; V v = null;
980 if (te.hash == hash &&
981 ((k = te.key) == key || (key != null && key.equals(k)))) {
982 if ((!matchValue || (v = te.value) == value ||
983 (value != null && value.equals(v)))) {
984 tab[index] = ((e = te.next) == null)
985 ? emptyXNode()
986 : new XNode(hash, e.key, e.value, e.next);
987 ++modCount;
988 --size;
989 return Optional.ofNullable(v);
990 }
991 } else if ((e = te.next) != null) {
992 Node<K,V> p = null;
993 if (e instanceof TreeNode)
994 node = ((TreeNode<K,V>)e).getTreeNode(hash, key);
995 else {
996 do {
997 if (e.hash == hash &&
998 ((k = e.key) == key ||
999 (key != null && key.equals(k)))) {
1000 node = e;
1001 break;
1002 }
1003 p = e;
1004 } while ((e = e.next) != null);
1005 }
1006
1007 if (node != null && (!matchValue || (v = node.value) == value ||
1008 (value != null && value.equals(v)))) {
1009 if (node instanceof TreeNode)
1010 ((TreeNode<K,V>)node).removeTreeNode(this, tab, movable);
1011 else if (p == null)
1012 tab[index] = new XNode(hash, node.key, node.value, node.next);
1013 else
1014 p.next = node.next;
1015 ++modCount;
1016 --size;
1017 return Optional.of(node.value);
1018 }
1019 }
1020 }
1021 return Optional.empty();
1022 }
1023
1024 /**
1025 * Removes all of the mappings from this map.
1026 * The map will be empty after this call returns.
1027 */
1028 public void clear() {
1029 modCount++;
1030 if (table != null && size > 0) {
1031 size = 0;
1032 table = null;
1033 threshold = 0;
1034 }
1035 }
1036
1037 /**
1038 * Returns {@code true} if this map maps one or more keys to the
1039 * specified value.
1040 *
1041 * @param value value whose presence in this map is to be tested
1042 * @return {@code true} if this map maps one or more keys to the
1043 * specified value
1044 */
1045 public boolean containsValue(Object value) {
1046 XNode<K,V>[] tab; V v;
1047 if ((tab = table) != null && size > 0) {
1048 for (XNode<K,V> te : tab) {
1049 if (!te.isEmpty()) {
1050 if ((v = te.value) == value ||
1051 (value != null && value.equals(v)))
1052 return true;
1053 for (Node<K, V> e = te.next; e != null; e = e.next) {
1054 if ((v = e.value) == value ||
1055 (value != null && value.equals(v)))
1056 return true;
1057 }
1058 }
1059 }
1060 }
1061 return false;
1062 }
1063
1064 /**
1065 * Returns a {@link Set} view of the keys contained in this map.
1066 * The set is backed by the map, so changes to the map are
1067 * reflected in the set, and vice-versa. If the map is modified
1068 * while an iteration over the set is in progress (except through
1069 * the iterator's own {@code remove} operation), the results of
1070 * the iteration are undefined. The set supports element removal,
1071 * which removes the corresponding mapping from the map, via the
1072 * {@code Iterator.remove}, {@code Set.remove},
1073 * {@code removeAll}, {@code retainAll}, and {@code clear}
1074 * operations. It does not support the {@code add} or {@code addAll}
1075 * operations.
1076 *
1077 * @return a set view of the keys contained in this map
1078 */
1079 public Set<K> keySet() {
1080 Set<K> ks = keySet;
1081 if (ks == null) {
1082 ks = new KeySet();
1083 keySet = ks;
1084 }
1085 return ks;
1086 }
1087
1088 /**
1089 * Prepares the array for {@link Collection#toArray(Object[])} implementation.
1090 * If supplied array is smaller than this map size, a new array is allocated.
1091 * If supplied array is bigger than this map size, a null is written at size index.
1092 *
1093 * @param a an original array passed to {@code toArray()} method
1094 * @param <T> type of array elements
1095 * @return an array ready to be filled and returned from {@code toArray()} method.
1096 */
1097 @SuppressWarnings("unchecked")
1098 final <T> T[] prepareArray(T[] a) {
1099 int size = this.size;
1100 if (a.length < size) {
1101 return (T[]) java.lang.reflect.Array
1102 .newInstance(a.getClass().getComponentType(), size);
1103 }
1104 if (a.length > size) {
1105 a[size] = null;
1106 }
1107 return a;
1108 }
1109
1110 /**
1111 * Fills an array with this map keys and returns it. This method assumes
1112 * that input array is big enough to fit all the keys. Use
1113 * {@link #prepareArray(Object[])} to ensure this.
1114 *
1115 * @param a an array to fill
1116 * @param <T> type of array elements
1117 * @return supplied array
1118 */
1119 <T> T[] keysToArray(T[] a) {
1120 Object[] r = a;
1121 XNode<K,V>[] tab;
1122 int idx = 0;
1123 int i = 0;
1124 if (size > 0 && (tab = table) != null) {
1125 for (XNode<K,V> te : tab) {
1126 if (!te.isEmpty()) {
1127 r[idx++] = te.key;
1128 for (Node<K, V> e = te.next; e != null; e = e.next) {
1129 r[idx++] = e.key;
1130 }
1131 }
1132 }
1133 }
1134 return a;
1135 }
1136
1137 /**
1138 * Fills an array with this map values and returns it. This method assumes
1139 * that input array is big enough to fit all the values. Use
1140 * {@link #prepareArray(Object[])} to ensure this.
1141 *
1142 * @param a an array to fill
1143 * @param <T> type of array elements
1144 * @return supplied array
1145 */
1146 <T> T[] valuesToArray(T[] a) {
1147 Object[] r = a;
1148 XNode<K,V>[] tab;
1149 int idx = 0;
1150 if (size > 0 && (tab = table) != null) {
1151 for (XNode<K,V> te : tab) {
1152 if (!te.isEmpty()) {
1153 r[idx++] = te.value;
1154 for (Node<K, V> e = te.next; e != null; e = e.next) {
1155 r[idx++] = e.value;
1156 }
1157 }
1158 }
1159 }
1160 return a;
1161 }
1162
1163 final class KeySet extends AbstractSet<K> {
1164 public final int size() { return size; }
1165 public final void clear() { XHashMap.this.clear(); }
1166 public final Iterator<K> iterator() { return new KeyIterator(); }
1167 public final boolean contains(Object o) { return containsKey(o); }
1168 public final boolean remove(Object key) {
1169 return removeNode(hash(key), key, null, false, true).isPresent();
1170 }
1171
1172 public Object[] toArray() {
1173 return keysToArray(new Object[size]);
1174 }
1175
1176 public <T> T[] toArray(T[] a) {
1177 return keysToArray(prepareArray(a));
1178 }
1179
1180 public final void forEach(Consumer<? super K> action) {
1181 XNode<K,V>[] tab;
1182 if (action == null)
1183 throw new NullPointerException();
1184 if (size > 0 && (tab = table) != null) {
1185 int mc = modCount;
1186 for (XNode<K,V> te : tab) {
1187 if (!te.isEmpty()) {
1188 action.accept(te.key);
1189 for (Node<K, V> e = te.next; e != null; e = e.next)
1190 action.accept(e.key);
1191 }
1192 }
1193 if (modCount != mc)
1194 throw new ConcurrentModificationException();
1195 }
1196 }
1197 }
1198
1199 /**
1200 * Returns a {@link Collection} view of the values contained in this map.
1201 * The collection is backed by the map, so changes to the map are
1202 * reflected in the collection, and vice-versa. If the map is
1203 * modified while an iteration over the collection is in progress
1204 * (except through the iterator's own {@code remove} operation),
1205 * the results of the iteration are undefined. The collection
1206 * supports element removal, which removes the corresponding
1207 * mapping from the map, via the {@code Iterator.remove},
1208 * {@code Collection.remove}, {@code removeAll},
1209 * {@code retainAll} and {@code clear} operations. It does not
1210 * support the {@code add} or {@code addAll} operations.
1211 *
1212 * @return a view of the values contained in this map
1213 */
1214 public Collection<V> values() {
1215 Collection<V> vs = values;
1216 if (vs == null) {
1217 vs = new Values();
1218 values = vs;
1219 }
1220 return vs;
1221 }
1222
1223 final class Values extends AbstractCollection<V> {
1224 public final int size() { return size; }
1225 public final void clear() { XHashMap.this.clear(); }
1226 public final Iterator<V> iterator() { return new ValueIterator(); }
1227 public final boolean contains(Object o) { return containsValue(o); }
1228
1229 public Object[] toArray() {
1230 return valuesToArray(new Object[size]);
1231 }
1232
1233 public <T> T[] toArray(T[] a) {
1234 return valuesToArray(prepareArray(a));
1235 }
1236
1237 public final void forEach(Consumer<? super V> action) {
1238 XNode<K,V>[] tab;
1239 if (action == null)
1240 throw new NullPointerException();
1241 if (size > 0 && (tab = table) != null) {
1242 int mc = modCount;
1243 for (XNode<K,V> te : tab) {
1244 if (!te.isEmpty()) {
1245 action.accept(te.value);
1246 for (Node<K, V> e = te.next; e != null; e = e.next)
1247 action.accept(e.value);
1248 }
1249 }
1250 if (modCount != mc)
1251 throw new ConcurrentModificationException();
1252 }
1253 }
1254 }
1255
1256 /**
1257 * Returns a {@link Set} view of the mappings contained in this map.
1258 * The set is backed by the map, so changes to the map are
1259 * reflected in the set, and vice-versa. If the map is modified
1260 * while an iteration over the set is in progress (except through
1261 * the iterator's own {@code remove} operation, or through the
1262 * {@code setValue} operation on a map entry returned by the
1263 * iterator) the results of the iteration are undefined. The set
1264 * supports element removal, which removes the corresponding
1265 * mapping from the map, via the {@code Iterator.remove},
1266 * {@code Set.remove}, {@code removeAll}, {@code retainAll} and
1267 * {@code clear} operations. It does not support the
1268 * {@code add} or {@code addAll} operations.
1269 *
1270 * @return a set view of the mappings contained in this map
1271 */
1272 public Set<Map.Entry<K,V>> entrySet() {
1273 Set<Map.Entry<K,V>> es;
1274 return (es = entrySet) == null ? (entrySet = new EntrySet()) : es;
1275 }
1276
1277 final class EntrySet extends AbstractSet<Map.Entry<K,V>> {
1278 public final int size() { return size; }
1279 public final void clear() { XHashMap.this.clear(); }
1280 public final Iterator<Map.Entry<K,V>> iterator() {
1281 return new EntryIterator();
1282 }
1283 public final boolean contains(Object o) {
1284 if (!(o instanceof Map.Entry))
1285 return false;
1286 Map.Entry<?,?> e = (Map.Entry<?,?>) o;
1287 Object key = e.getKey();
1288 Node<K,V> candidate = getNode(hash(key), key);
1289 return candidate != null && candidate.equals(e);
1290 }
1291 public final boolean remove(Object o) {
1292 if (o instanceof Map.Entry) {
1293 Map.Entry<?,?> e = (Map.Entry<?,?>) o;
1294 Object key = e.getKey();
1295 Object value = e.getValue();
1296 return removeNode(hash(key), key, value, true, true).isPresent();
1297 }
1298 return false;
1299 }
1300 public final void forEach(Consumer<? super Map.Entry<K,V>> action) {
1301 XNode<K,V>[] tab;
1302 if (action == null)
1303 throw new NullPointerException();
1304 if (size > 0 && (tab = table) != null) {
1305 int mc = modCount;
1306 for (XNode<K,V> te : tab) {
1307 if (!te.isEmpty()) {
1308 action.accept(new XNodeWrapper(te.hash & (tab.length - 1)));
1309 for (Node<K, V> e = te.next; e != null; e = e.next)
1310 action.accept(e);
1311 }
1312 }
1313 if (modCount != mc)
1314 throw new ConcurrentModificationException();
1315 }
1316 }
1317 }
1318
1319 // Overrides of JDK8 Map extension methods
1320
1321 @Override
1322 public V getOrDefault(Object key, V defaultValue) {
1323 Node<K,V> e;
1324 return (e = getNode(hash(key), key)) == null ? defaultValue : e.value;
1325 }
1326
1327 @Override
1328 public V putIfAbsent(K key, V value) {
1329 return putVal(hash(key), key, value, true, true);
1330 }
1331
1332 @Override
1333 public boolean remove(Object key, Object value) {
1334 return removeNode(hash(key), key, value, true, true).isPresent();
1335 }
1336
1337 @Override
1338 public boolean replace(K key, V oldValue, V newValue) {
1339 Node<K,V> e; V v;
1340 if ((e = getNode(hash(key), key)) != null &&
1341 ((v = e.value) == oldValue || (v != null && v.equals(oldValue)))) {
1342 e.value = newValue;
1343 return true;
1344 }
1345 return false;
1346 }
1347
1348 @Override
1349 public V replace(K key, V value) {
1350 Node<K,V> e;
1351 if ((e = getNode(hash(key), key)) != null) {
1352 V oldValue = e.value;
1353 e.value = value;
1354 return oldValue;
1355 }
1356 return null;
1357 }
1358
1359 /**
1360 * {@inheritDoc}
1361 *
1362 * <p>This method will, on a best-effort basis, throw a
1363 * {@link ConcurrentModificationException} if it is detected that the
1364 * mapping function modifies this map during computation.
1365 *
1366 * @throws ConcurrentModificationException if it is detected that the
1367 * mapping function modified this map
1368 */
1369 @Override
1370 public V computeIfAbsent(K key,
1371 Function<? super K, ? extends V> mappingFunction) {
1372 if (mappingFunction == null)
1373 throw new NullPointerException();
1374 int hash = hash(key);
1375 XNode<K,V>[] tab; XNode<K,V> first; int n, i;
1376 int binCount = 0;
1377 TreeNode<K,V> t = null;
1378 Node<K,V> old = null;
1379 if (size > threshold || (tab = table) == null ||
1380 (n = tab.length) == 0)
1381 n = (tab = resize()).length;
1382 if (!(first = tab[i = (n - 1) & hash]).isEmpty()) {
1383 K k;
1384 if (first.hash == hash &&
1385 ((k = first.key) == key || (key != null && key.equals(k)))) {
1386 return first.value;
1387 }
1388 Node<K,V> e = first.next;
1389 if (e instanceof TreeNode)
1390 old = (t = (TreeNode<K,V>)e).getTreeNode(hash, key);
1391 else {
1392 do {
1393 if (e.hash == hash &&
1394 ((k = e.key) == key || (key != null && key.equals(k)))) {
1395 old = e;
1396 break;
1397 }
1398 ++binCount;
1399 } while ((e = e.next) != null);
1400 }
1401
1402 V oldValue;
1403 if (old != null && (oldValue = old.value) != null) {
1404 return oldValue;
1405 }
1406 }
1407 int mc = modCount;
1408 V v = mappingFunction.apply(key);
1409 if (mc != modCount) { throw new ConcurrentModificationException(); }
1410 if (v == null) {
1411 return null;
1412 } else if (old != null) {
1413 old.value = v;
1414 return v;
1415 }
1416 else if (t != null)
1417 t.putTreeVal(this, tab, hash, key, v);
1418 else {
1419 Node<K,V> x = (tab[i].isEmpty()) ? null : newNode(hash, key, v, null);
1420 tab[i] = new XNode(hash, key, v, x);
1421 if (binCount >= TREEIFY_THRESHOLD - 1)
1422 treeifyBin(tab, hash);
1423 }
1424 modCount = mc + 1;
1425 ++size;
1426 return v;
1427 }
1428
1429 /**
1430 * {@inheritDoc}
1431 *
1432 * <p>This method will, on a best-effort basis, throw a
1433 * {@link ConcurrentModificationException} if it is detected that the
1434 * remapping function modifies this map during computation.
1435 *
1436 * @throws ConcurrentModificationException if it is detected that the
1437 * remapping function modified this map
1438 */
1439 @Override
1440 public V computeIfPresent(K key,
1441 BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
1442 if (remappingFunction == null)
1443 throw new NullPointerException();
1444 Node<K,V> e; V oldValue;
1445 int hash = hash(key);
1446 if ((e = getNode(hash, key)) != null &&
1447 (oldValue = e.value) != null) {
1448 int mc = modCount;
1449 V v = remappingFunction.apply(key, oldValue);
1450 if (mc != modCount) { throw new ConcurrentModificationException(); }
1451 if (v != null) {
1452 e.value = v;
1453 return v;
1454 }
1455 else
1456 removeNode(hash, key, null, false, true);
1457 }
1458 return null;
1459 }
1460
1461 /**
1462 * {@inheritDoc}
1463 *
1464 * <p>This method will, on a best-effort basis, throw a
1465 * {@link ConcurrentModificationException} if it is detected that the
1466 * remapping function modifies this map during computation.
1467 *
1468 * @throws ConcurrentModificationException if it is detected that the
1469 * remapping function modified this map
1470 */
1471 @Override
1472 public V compute(K key,
1473 BiFunction<? super K, ? super V, ? extends V> remappingFunction) {
1474 if (remappingFunction == null)
1475 throw new NullPointerException();
1476 int hash = hash(key);
1477 XNode<K,V>[] tab; XNode<K,V> first; int n, i;
1478 int binCount = 0;
1479 TreeNode<K,V> t = null;
1480 Node<K,V> old = null;
1481 if (size > threshold || (tab = table) == null ||
1482 (n = tab.length) == 0)
1483 n = (tab = resize()).length;
1484 if (!(first = tab[i = (n - 1) & hash]).isEmpty()) {
1485 Node<K,V> e = first.next;K k;
1486 if (first.hash == hash &&
1487 ((k = first.key) == key || (key != null && key.equals(k)))) {
1488 V v = remappingFunction.apply(k, first.value);
1489 tab[i] = new XNode(hash, k, v, e);
1490 return v;
1491 }
1492 if (e instanceof TreeNode)
1493 old = (t = (TreeNode<K,V>)e).getTreeNode(hash, key);
1494 else {
1495 do {
1496 if (e.hash == hash &&
1497 ((k = e.key) == key || (key != null && key.equals(k)))) {
1498 old = e;
1499 break;
1500 }
1501 ++binCount;
1502 } while ((e = e.next) != null);
1503 }
1504 }
1505 V oldValue = (old == null) ? null : old.value;
1506 int mc = modCount;
1507 V v = remappingFunction.apply(key, oldValue);
1508 if (mc != modCount) { throw new ConcurrentModificationException(); }
1509 if (old != null) {
1510 if (v != null) {
1511 old.value = v;
1512 }
1513 else
1514 removeNode(hash, key, null, false, true);
1515 }
1516 else if (v != null) {
1517 if (t != null)
1518 t.putTreeVal(this, tab, hash, key, v);
1519 else {
1520 Node<K,V> x = (tab[i].isEmpty()) ? null : newNode(hash, key, v, null);
1521 tab[i] = new XNode(hash, key, v, x);
1522 if (binCount >= TREEIFY_THRESHOLD - 1)
1523 treeifyBin(tab, hash);
1524 }
1525 modCount = mc + 1;
1526 ++size;
1527 }
1528 return v;
1529 }
1530
1531 /**
1532 * {@inheritDoc}
1533 *
1534 * <p>This method will, on a best-effort basis, throw a
1535 * {@link ConcurrentModificationException} if it is detected that the
1536 * remapping function modifies this map during computation.
1537 *
1538 * @throws ConcurrentModificationException if it is detected that the
1539 * remapping function modified this map
1540 */
1541 @Override
1542 public V merge(K key, V value,
1543 BiFunction<? super V, ? super V, ? extends V> remappingFunction) {
1544 if (value == null || remappingFunction == null)
1545 throw new NullPointerException();
1546 int hash = hash(key);
1547 XNode<K,V>[] tab; XNode<K,V> first; int n, i;
1548 int binCount = 0;
1549 TreeNode<K,V> t = null;
1550 Node<K,V> old = null;
1551 if (size > threshold || (tab = table) == null ||
1552 (n = tab.length) == 0)
1553 n = (tab = resize()).length;
1554 if (!(first = tab[i = (n - 1) & hash]).isEmpty()) {
1555 Node<K,V> e = first.next;K k;
1556 if (first.hash == hash &&
1557 ((k = first.key) == key || (key != null && key.equals(k)))) {
1558 V v = remappingFunction.apply(first.value, value);
1559 tab[i] = new XNode(hash, k, v, e);
1560 return v;
1561 }
1562 if (e instanceof TreeNode)
1563 old = (t = (TreeNode<K,V>)e).getTreeNode(hash, key);
1564 else {
1565 do {
1566 if (e.hash == hash &&
1567 ((k = e.key) == key || (key != null && key.equals(k)))) {
1568 old = e;
1569 break;
1570 }
1571 ++binCount;
1572 } while ((e = e.next) != null);
1573 }
1574 }
1575 if (old != null) {
1576 V v;
1577 if (old.value != null) {
1578 int mc = modCount;
1579 v = remappingFunction.apply(old.value, value);
1580 if (mc != modCount) {
1581 throw new ConcurrentModificationException();
1582 }
1583 } else {
1584 v = value;
1585 }
1586 if (v != null) {
1587 old.value = v;
1588 }
1589 else
1590 removeNode(hash, key, null, false, true);
1591 return v;
1592 } else {
1593 if (t != null)
1594 t.putTreeVal(this, tab, hash, key, value);
1595 else {
1596 Node<K,V> x = (tab[i].isEmpty()) ? null
1597 : newNode(hash, tab[i].key, tab[i].value, null);
1598 tab[i] = new XNode(hash, key, value, x);
1599 if (binCount >= TREEIFY_THRESHOLD - 1)
1600 treeifyBin(tab, hash);
1601 }
1602 ++modCount;
1603 ++size;
1604 return value;
1605 }
1606 }
1607
1608 @Override
1609 public void forEach(BiConsumer<? super K, ? super V> action) {
1610 XNode<K,V>[] tab;
1611 if (action == null)
1612 throw new NullPointerException();
1613 if (size > 0 && (tab = table) != null) {
1614 int mc = modCount;
1615 for (XNode<K,V> te : tab) {
1616 if (!te.isEmpty()) {
1617 action.accept(te.key, te.value);
1618 for (Node<K, V> e = te.next; e != null; e = e.next)
1619 action.accept(e.key, e.value);
1620 }
1621 }
1622 if (modCount != mc)
1623 throw new ConcurrentModificationException();
1624 }
1625 }
1626
1627 @Override
1628 public void replaceAll(BiFunction<? super K, ? super V, ? extends V> function) {
1629 XNode<K,V>[] tab;
1630 if (function == null)
1631 throw new NullPointerException();
1632 if (size > 0 && (tab = table) != null) {
1633 int mc = modCount;
1634 for (XNode<K,V> te : tab) {
1635 if (!te.isEmpty()) {
1636 V v = function.apply(te.key, te.value);
1637 tab[te.hash & (tab.length -1)] = new XNode(te.hash, te.key, v, te.next);
1638 for (Node<K, V> e = te.next; e != null; e = e.next)
1639 e.value = function.apply(e.key, e.value);
1640 }
1641 }
1642 if (modCount != mc)
1643 throw new ConcurrentModificationException();
1644 }
1645 }
1646
1647 /* ------------------------------------------------------------ */
1648 // Cloning and serialization
1649
1650 /**
1651 * Returns a shallow copy of this {@code HashMap} instance: the keys and
1652 * values themselves are not cloned.
1653 *
1654 * @return a shallow copy of this map
1655 */
1656 @SuppressWarnings("unchecked")
1657 @Override
1658 public Object clone() {
1659 XHashMap<K,V> result;
1660 try {
1661 result = (XHashMap<K,V>)super.clone();
1662 } catch (CloneNotSupportedException e) {
1663 // this shouldn't happen, since we are Cloneable
1664 throw new InternalError(e);
1665 }
1666 result.reinitialize();
1667 result.putMapEntries(this, false);
1668 return result;
1669 }
1670
1671 // These methods are also used when serializing HashSets
1672 final float loadFactor() { return loadFactor; }
1673 final int capacity() {
1674 return (table != null) ? table.length :
1675 (threshold > 0) ? threshold :
1676 DEFAULT_INITIAL_CAPACITY;
1677 }
1678
1679 /**
1680 * Saves this map to a stream (that is, serializes it).
1681 *
1682 * @param s the stream
1683 * @throws IOException if an I/O error occurs
1684 * @serialData The <i>capacity</i> of the HashMap (the length of the
1685 * bucket array) is emitted (int), followed by the
1686 * <i>size</i> (an int, the number of key-value
1687 * mappings), followed by the key (Object) and value (Object)
1688 * for each key-value mapping. The key-value mappings are
1689 * emitted in no particular order.
1690 */
1691 private void writeObject(java.io.ObjectOutputStream s)
1692 throws IOException {
1693 int buckets = capacity();
1694 // Write out the threshold, loadfactor, and any hidden stuff
1695 s.defaultWriteObject();
1696 s.writeInt(buckets);
1697 s.writeInt(size);
1698 internalWriteEntries(s);
1699 }
1700
1701 /**
1702 * Reconstitutes this map from a stream (that is, deserializes it).
1703 * @param s the stream
1704 * @throws ClassNotFoundException if the class of a serialized object
1705 * could not be found
1706 * @throws IOException if an I/O error occurs
1707 */
1708 private void readObject(java.io.ObjectInputStream s)
1709 throws IOException, ClassNotFoundException {
1710 // Read in the threshold (ignored), loadfactor, and any hidden stuff
1711 s.defaultReadObject();
1712 reinitialize();
1713 if (loadFactor <= 0 || Float.isNaN(loadFactor))
1714 throw new InvalidObjectException("Illegal load factor: " +
1715 loadFactor);
1716 s.readInt(); // Read and ignore number of buckets
1717 int mappings = s.readInt(); // Read number of mappings (size)
1718 if (mappings < 0)
1719 throw new InvalidObjectException("Illegal mappings count: " +
1720 mappings);
1721 else if (mappings > 0) { // (if zero, use defaults)
1722 // Size the table using given load factor only if within
1723 // range of 0.25...4.0
1724 float lf = Math.min(Math.max(0.25f, loadFactor), 4.0f);
1725 float fc = (float)mappings / lf + 1.0f;
1726 int cap = ((fc < DEFAULT_INITIAL_CAPACITY) ?
1727 DEFAULT_INITIAL_CAPACITY :
1728 (fc >= MAXIMUM_CAPACITY) ?
1729 MAXIMUM_CAPACITY :
1730 tableSizeFor((int)fc));
1731 float ft = (float)cap * lf;
1732 threshold = ((cap < MAXIMUM_CAPACITY && ft < MAXIMUM_CAPACITY) ?
1733 (int)ft : Integer.MAX_VALUE);
1734
1735 // Check Map.Entry[].class since it's the nearest public type to
1736 // what we're actually creating.
1737 @SuppressWarnings({"rawtypes","unchecked"})
1738 XNode<K,V>[] tab = (XNode<K,V>[])new XNode[cap];
1739 table = tab;
1740
1741 // Read the keys and values, and put the mappings in the HashMap
1742 for (int i = 0; i < mappings; i++) {
1743 @SuppressWarnings("unchecked")
1744 K key = (K) s.readObject();
1745 @SuppressWarnings("unchecked")
1746 V value = (V) s.readObject();
1747 putVal(hash(key), key, value, false, false);
1748 }
1749 }
1750 }
1751
1752 /* ------------------------------------------------------------ */
1753 // iterators
1754
1755 static final Node<?,?> START_INDEX = new Node(0, null, null, null);
1756
1757 abstract class HashIterator {
1758 Node<K,V> next; // next entry to return
1759 Node<K,V> current; // current entry
1760 int expectedModCount; // for fast-fail
1761 int index; // current slot
1762
1763
1764 HashIterator() {
1765 expectedModCount = modCount;
1766 XNode<K,V>[] t = table;
1767 current = next = null;
1768 index = 0;
1769 if (t != null && size > 0) { // advance to first entry
1770 XNode<K,V> n = emptyXNode();
1771 for (; index < t.length && (n = t[index]).isEmpty(); index++) {
1772 }
1773 next = (Node<K,V>)START_INDEX;
1774 }
1775 }
1776
1777 public final boolean hasNext() {
1778 return next != null;
1779 }
1780
1781 final Entry<K,V> nextNode() {
1782 XNode<K,V>[] t;
1783 Node<K,V> e = next;
1784 if (modCount != expectedModCount)
1785 throw new ConcurrentModificationException();
1786 if (e == null)
1787 throw new NoSuchElementException();
1788 if ((next = (current = e).next) == null && (t = table) != null) {
1789 var ret = (e == START_INDEX) ? new XNodeWrapper(index++) : e;
1790 for (; index < t.length && (t[index]).isEmpty(); index++) { }
1791 next = (index < t.length) ? (Node<K, V>) START_INDEX : null;
1792 return ret;
1793 }
1794 return e;
1795 }
1796
1797 public final void remove() {
1798 Node<K,V> p = current;
1799 if (p == null)
1800 throw new IllegalStateException();
1801 if (modCount != expectedModCount)
1802 throw new ConcurrentModificationException();
1803 current = null;
1804 removeNode(p.hash, p.key, null, false, false);
1805 expectedModCount = modCount;
1806 }
1807 }
1808
1809 final class KeyIterator extends HashIterator
1810 implements Iterator<K> {
1811 public final K next() { return nextNode().getKey(); }
1812 }
1813
1814 final class ValueIterator extends HashIterator
1815 implements Iterator<V> {
1816 public final V next() { return nextNode().getValue(); }
1817 }
1818
1819 final class EntryIterator extends HashIterator
1820 implements Iterator<Map.Entry<K,V>> {
1821 public final Map.Entry<K,V> next() { return nextNode(); }
1822 }
1823
1824 /*
1825 * The following package-protected methods are designed to be
1826 * overridden by LinkedHashMap, but not by any other subclass.
1827 * Nearly all other internal methods are also package-protected
1828 * but are declared final, so can be used by LinkedHashMap, view
1829 * classes, and HashSet.
1830 */
1831
1832 // Create a regular (non-tree) node
1833 Node<K,V> newNode(int hash, K key, V value, Node<K,V> next) {
1834 return new Node<>(hash, key, value, next);
1835 }
1836
1837 // For conversion from TreeNodes to plain nodes
1838 Node<K,V> replacementNode(Node<K,V> p, Node<K,V> next) {
1839 return new Node<>(p.hash, p.key, p.value, next);
1840 }
1841
1842 // Create a tree bin node
1843 TreeNode<K,V> newTreeNode(int hash, K key, V value, Node<K,V> next) {
1844 return new TreeNode<>(hash, key, value, next);
1845 }
1846
1847 // For treeifyBin
1848 TreeNode<K,V> replacementTreeNode(Node<K,V> p, Node<K,V> next) {
1849 return new TreeNode<>(p.hash, p.key, p.value, next);
1850 }
1851
1852 /**
1853 * Reset to initial default state. Called by clone and readObject.
1854 */
1855 void reinitialize() {
1856 table = null;
1857 entrySet = null;
1858 keySet = null;
1859 values = null;
1860 modCount = 0;
1861 threshold = 0;
1862 size = 0;
1863 }
1864
1865 // Called only from writeObject, to ensure compatible ordering.
1866 void internalWriteEntries(java.io.ObjectOutputStream s) throws IOException {
1867 XNode<K,V>[] tab;
1868 if (size > 0 && (tab = table) != null) {
1869 for (XNode<K,V> te : tab) {
1870 if (!te.isEmpty()) {
1871 s.writeObject(te.key);
1872 s.writeObject(te.value);
1873
1874 for (Node<K, V> e = te.next; e != null; e = e.next) {
1875 s.writeObject(e.key);
1876 s.writeObject(e.value);
1877 }
1878 }
1879 }
1880 }
1881 }
1882
1883 /* ------------------------------------------------------------ */
1884 // Tree bins
1885
1886 /**
1887 * Entry for Tree bins. Extends LinkedHashMap.Entry (which in turn
1888 * extends Node) so can be used as extension of either regular or
1889 * linked node.
1890 */
1891 static final class TreeNode<K,V> extends Node<K,V> {
1892 TreeNode<K,V> parent; // red-black tree links
1893 TreeNode<K,V> left;
1894 TreeNode<K,V> right;
1895 TreeNode<K,V> prev; // needed to unlink next upon deletion
1896 boolean red;
1897 TreeNode(int hash, K key, V val, Node<K,V> next) {
1898 super(hash, key, val, next);
1899 }
1900
1901 /**
1902 * Returns root of tree containing this node.
1903 */
1904 final TreeNode<K,V> root() {
1905 for (TreeNode<K,V> r = this, p;;) {
1906 if ((p = r.parent) == null)
1907 return r;
1908 r = p;
1909 }
1910 }
1911
1912 /**
1913 * Ensures that the given root is the first node of its bin.
1914 */
1915 static <K,V> void moveRootToFront(Node<K,V>[] tab, TreeNode<K,V> root) {
1916 int n;
1917 if (root != null && tab != null && (n = tab.length) > 0) {
1918 int index = (n - 1) & root.hash;
1919 TreeNode<K,V> first = (TreeNode<K,V>)tab[index];
1920 if (root != first) {
1921 Node<K,V> rn;
1922 tab[index] = root;
1923 TreeNode<K,V> rp = root.prev;
1924 if ((rn = root.next) != null)
1925 ((TreeNode<K,V>)rn).prev = rp;
1926 if (rp != null)
1927 rp.next = rn;
1928 if (first != null)
1929 first.prev = root;
1930 root.next = first;
1931 root.prev = null;
1932 }
1933 assert checkInvariants(root);
1934 }
1935 }
1936
1937 /**
1938 * Finds the node starting at root p with the given hash and key.
1939 * The kc argument caches comparableClassFor(key) upon first use
1940 * comparing keys.
1941 */
1942 final TreeNode<K,V> find(int h, Object k, Class<?> kc) {
1943 TreeNode<K,V> p = this;
1944 do {
1945 int ph, dir; K pk;
1946 TreeNode<K,V> pl = p.left, pr = p.right, q;
1947 if ((ph = p.hash) > h)
1948 p = pl;
1949 else if (ph < h)
1950 p = pr;
1951 else if ((pk = p.key) == k || (k != null && k.equals(pk)))
1952 return p;
1953 else if (pl == null)
1954 p = pr;
1955 else if (pr == null)
1956 p = pl;
1957 else if ((kc != null ||
1958 (kc = comparableClassFor(k)) != null) &&
1959 (dir = compareComparables(kc, k, pk)) != 0)
1960 p = (dir < 0) ? pl : pr;
1961 else if ((q = pr.find(h, k, kc)) != null)
1962 return q;
1963 else
1964 p = pl;
1965 } while (p != null);
1966 return null;
1967 }
1968
1969 /**
1970 * Calls find for root node.
1971 */
1972 final TreeNode<K,V> getTreeNode(int h, Object k) {
1973 return ((parent != null) ? root() : this).find(h, k, null);
1974 }
1975
1976 /**
1977 * Tie-breaking utility for ordering insertions when equal
1978 * hashCodes and non-comparable. We don't require a total
1979 * order, just a consistent insertion rule to maintain
1980 * equivalence across rebalancings. Tie-breaking further than
1981 * necessary simplifies testing a bit.
1982 */
1983 static int tieBreakOrder(Object a, Object b) {
1984 int d;
1985 if (a == null || b == null ||
1986 (d = a.getClass().getName().
1987 compareTo(b.getClass().getName())) == 0)
1988 d = (System.identityHashCode(a) <= System.identityHashCode(b) ?
1989 -1 : 1);
1990 return d;
1991 }
1992
1993 /**
1994 * Forms tree of the nodes linked from this node.
1995 */
1996 final void treeify(XNode<K,V>[] tab) {
1997 // TreeNode<K,V> root = null;
1998 // for (TreeNode<K,V> x = this, next; x != null; x = next) {
1999 // next = (TreeNode<K,V>)x.next;
2000 // x.left = x.right = null;
2001 // if (root == null) {
2002 // x.parent = null;
2003 // x.red = false;
2004 // root = x;
2005 // }
2006 // else {
2007 // K k = x.key;
2008 // int h = x.hash;
2009 // Class<?> kc = null;
2010 // for (TreeNode<K,V> p = root;;) {
2011 // int dir, ph;
2012 // K pk = p.key;
2013 // if ((ph = p.hash) > h)
2014 // dir = -1;
2015 // else if (ph < h)
2016 // dir = 1;
2017 // else if ((kc == null &&
2018 // (kc = comparableClassFor(k)) == null) ||
2019 // (dir = compareComparables(kc, k, pk)) == 0)
2020 // dir = tieBreakOrder(k, pk);
2021 //
2022 // TreeNode<K,V> xp = p;
2023 // if ((p = (dir <= 0) ? p.left : p.right) == null) {
2024 // x.parent = xp;
2025 // if (dir <= 0)
2026 // xp.left = x;
2027 // else
2028 // xp.right = x;
2029 // root = balanceInsertion(root, x);
2030 // break;
2031 // }
2032 // }
2033 // }
2034 // }
2035 // moveRootToFront(tab, root);
2036 }
2037
2038 /**
2039 * Returns a list of non-TreeNodes replacing those linked from
2040 * this node.
2041 */
2042 final Node<K,V> untreeify(XHashMap<K,V> map) {
2043 Node<K,V> hd = null, tl = null;
2044 for (Node<K,V> q = this; q != null; q = q.next) {
2045 Node<K,V> p = map.replacementNode(q, null);
2046 if (tl == null)
2047 hd = p;
2048 else
2049 tl.next = p;
2050 tl = p;
2051 }
2052 return hd;
2053 }
2054
2055 /**
2056 * Tree version of putVal.
2057 */
2058 final TreeNode<K,V> putTreeVal(XHashMap<K,V> map, XNode<K,V>[] tab,
2059 int h, K k, V v) {
2060 // Class<?> kc = null;
2061 // boolean searched = false;
2062 // TreeNode<K,V> root = (parent != null) ? root() : this;
2063 // for (TreeNode<K,V> p = root;;) {
2064 // int dir, ph; K pk;
2065 // if ((ph = p.hash) > h)
2066 // dir = -1;
2067 // else if (ph < h)
2068 // dir = 1;
2069 // else if ((pk = p.key) == k || (k != null && k.equals(pk)))
2070 // return p;
2071 // else if ((kc == null &&
2072 // (kc = comparableClassFor(k)) == null) ||
2073 // (dir = compareComparables(kc, k, pk)) == 0) {
2074 // if (!searched) {
2075 // TreeNode<K,V> q, ch;
2076 // searched = true;
2077 // if (((ch = p.left) != null &&
2078 // (q = ch.find(h, k, kc)) != null) ||
2079 // ((ch = p.right) != null &&
2080 // (q = ch.find(h, k, kc)) != null))
2081 // return q;
2082 // }
2083 // dir = tieBreakOrder(k, pk);
2084 // }
2085 //
2086 // TreeNode<K,V> xp = p;
2087 // if ((p = (dir <= 0) ? p.left : p.right) == null) {
2088 // Node<K,V> xpn = xp.next;
2089 // TreeNode<K,V> x = map.newTreeNode(h, k, v, xpn);
2090 // if (dir <= 0)
2091 // xp.left = x;
2092 // else
2093 // xp.right = x;
2094 // xp.next = x;
2095 // x.parent = x.prev = xp;
2096 // if (xpn != null)
2097 // ((TreeNode<K,V>)xpn).prev = x;
2098 // moveRootToFront(tab, balanceInsertion(root, x));
2099 // return null;
2100 // }
2101 // }
2102 return null;
2103 }
2104
2105 /**
2106 * Removes the given node, that must be present before this call.
2107 * This is messier than typical red-black deletion code because we
2108 * cannot swap the contents of an interior node with a leaf
2109 * successor that is pinned by "next" pointers that are accessible
2110 * independently during traversal. So instead we swap the tree
2111 * linkages. If the current tree appears to have too few nodes,
2112 * the bin is converted back to a plain bin. (The test triggers
2113 * somewhere between 2 and 6 nodes, depending on tree structure).
2114 */
2115 final void removeTreeNode(XHashMap<K,V> map, XNode<K,V>[] tab,
2116 boolean movable) {
2117 // int n;
2118 // if (tab == null || (n = tab.length) == 0)
2119 // return;
2120 // int index = (n - 1) & hash;
2121 // TreeNode<K,V> first = (TreeNode<K,V>)tab[index], root = first, rl;
2122 // TreeNode<K,V> succ = (TreeNode<K,V>)next, pred = prev;
2123 // if (pred == null)
2124 // tab[index] = first = succ;
2125 // else
2126 // pred.next = succ;
2127 // if (succ != null)
2128 // succ.prev = pred;
2129 // if (first == null)
2130 // return;
2131 // if (root.parent != null)
2132 // root = root.root();
2133 // if (root == null
2134 // || (movable
2135 // && (root.right == null
2136 // || (rl = root.left) == null
2137 // || rl.left == null))) {
2138 // tab[index] = first.untreeify(map); // too small
2139 // return;
2140 // }
2141 // TreeNode<K,V> p = this, pl = left, pr = right, replacement;
2142 // if (pl != null && pr != null) {
2143 // TreeNode<K,V> s = pr, sl;
2144 // while ((sl = s.left) != null) // find successor
2145 // s = sl;
2146 // boolean c = s.red; s.red = p.red; p.red = c; // swap colors
2147 // TreeNode<K,V> sr = s.right;
2148 // TreeNode<K,V> pp = p.parent;
2149 // if (s == pr) { // p was s's direct parent
2150 // p.parent = s;
2151 // s.right = p;
2152 // }
2153 // else {
2154 // TreeNode<K,V> sp = s.parent;
2155 // if ((p.parent = sp) != null) {
2156 // if (s == sp.left)
2157 // sp.left = p;
2158 // else
2159 // sp.right = p;
2160 // }
2161 // if ((s.right = pr) != null)
2162 // pr.parent = s;
2163 // }
2164 // p.left = null;
2165 // if ((p.right = sr) != null)
2166 // sr.parent = p;
2167 // if ((s.left = pl) != null)
2168 // pl.parent = s;
2169 // if ((s.parent = pp) == null)
2170 // root = s;
2171 // else if (p == pp.left)
2172 // pp.left = s;
2173 // else
2174 // pp.right = s;
2175 // if (sr != null)
2176 // replacement = sr;
2177 // else
2178 // replacement = p;
2179 // }
2180 // else if (pl != null)
2181 // replacement = pl;
2182 // else if (pr != null)
2183 // replacement = pr;
2184 // else
2185 // replacement = p;
2186 // if (replacement != p) {
2187 // TreeNode<K,V> pp = replacement.parent = p.parent;
2188 // if (pp == null)
2189 // (root = replacement).red = false;
2190 // else if (p == pp.left)
2191 // pp.left = replacement;
2192 // else
2193 // pp.right = replacement;
2194 // p.left = p.right = p.parent = null;
2195 // }
2196 //
2197 // TreeNode<K,V> r = p.red ? root : balanceDeletion(root, replacement);
2198 //
2199 // if (replacement == p) { // detach
2200 // TreeNode<K,V> pp = p.parent;
2201 // p.parent = null;
2202 // if (pp != null) {
2203 // if (p == pp.left)
2204 // pp.left = null;
2205 // else if (p == pp.right)
2206 // pp.right = null;
2207 // }
2208 // }
2209 // if (movable)
2210 // moveRootToFront(tab, r);
2211 }
2212
2213 /**
2214 * Splits nodes in a tree bin into lower and upper tree bins,
2215 * or untreeifies if now too small. Called only from resize;
2216 * see above discussion about split bits and indices.
2217 *
2218 * @param map the map
2219 * @param tab the table for recording bin heads
2220 * @param index the index of the table being split
2221 * @param bit the bit of hash to split on
2222 */
2223 final void split(XHashMap<K,V> map, XNode<K,V>[] tab, int index, int bit) {
2224 // TreeNode<K,V> b = this;
2225 // // Relink into lo and hi lists, preserving order
2226 // TreeNode<K,V> loHead = null, loTail = null;
2227 // TreeNode<K,V> hiHead = null, hiTail = null;
2228 // int lc = 0, hc = 0;
2229 // for (TreeNode<K,V> e = b, next; e != null; e = next) {
2230 // next = (TreeNode<K,V>)e.next;
2231 // e.next = null;
2232 // if ((e.hash & bit) == 0) {
2233 // if ((e.prev = loTail) == null)
2234 // loHead = e;
2235 // else
2236 // loTail.next = e;
2237 // loTail = e;
2238 // ++lc;
2239 // }
2240 // else {
2241 // if ((e.prev = hiTail) == null)
2242 // hiHead = e;
2243 // else
2244 // hiTail.next = e;
2245 // hiTail = e;
2246 // ++hc;
2247 // }
2248 // }
2249 //
2250 // if (loHead != null) {
2251 // if (lc <= UNTREEIFY_THRESHOLD)
2252 // tab[index] = loHead.untreeify(map);
2253 // else {
2254 // tab[index] = loHead;
2255 // if (hiHead != null) // (else is already treeified)
2256 // loHead.treeify(tab);
2257 // }
2258 // }
2259 // if (hiHead != null) {
2260 // if (hc <= UNTREEIFY_THRESHOLD)
2261 // tab[index + bit] = hiHead.untreeify(map);
2262 // else {
2263 // tab[index + bit] = hiHead;
2264 // if (loHead != null)
2265 // hiHead.treeify(tab);
2266 // }
2267 // }
2268 }
2269
2270 /**
2271 * Recursive invariant check
2272 */
2273 static <K,V> boolean checkInvariants(TreeNode<K,V> t) {
2274 TreeNode<K,V> tp = t.parent, tl = t.left, tr = t.right,
2275 tb = t.prev, tn = (TreeNode<K,V>)t.next;
2276 if (tb != null && tb.next != t)
2277 return false;
2278 if (tn != null && tn.prev != t)
2279 return false;
2280 if (tp != null && t != tp.left && t != tp.right)
2281 return false;
2282 if (tl != null && (tl.parent != t || tl.hash > t.hash))
2283 return false;
2284 if (tr != null && (tr.parent != t || tr.hash < t.hash))
2285 return false;
2286 if (t.red && tl != null && tl.red && tr != null && tr.red)
2287 return false;
2288 if (tl != null && !checkInvariants(tl))
2289 return false;
2290 if (tr != null && !checkInvariants(tr))
2291 return false;
2292 return true;
2293 }
2294 }
2295
2296
2297 public void dumpStats(PrintStream out) {
2298 out.printf("%s instance: size: %d%n", this.getClass().getName(), this.size());
2299 long size = heapSize();
2300 long bytesPer = size / this.size();
2301 out.printf(" heap size: %d(bytes), avg bytes per entry: %d, table len: %d%n",
2302 size, bytesPer, table.length);
2303 long[] types = entryTypes();
2304 out.printf(" values: %d, empty: %d%n", types[0], types[1]);
2305 int[] rehashes = entryRehashes();
2306 out.printf(" hash collision histogram: max: %d, %s%n",
2307 rehashes.length - 1, Arrays.toString(rehashes));
2308 }
2309
2310 private long[] entryTypes() {
2311 long[] counts = new long[3];
2312 for (XNode<K,V> te : table) {
2313 counts[te.isEmpty() ? 1 : 0]++;
2314 }
2315 return counts;
2316 }
2317
2318 // Returns a histogram array of the number of rehashs needed to find each key.
2319 private int[] entryRehashes() {
2320 int[] counts = new int[table.length + 1];
2321 XNode<K,V>[] tab = table;
2322 for (XNode<K,V> te : tab) {
2323 if (!te.isEmpty()) {
2324 int count = 0;
2325 for (Node<K, V> e = te.next; e != null; e = e.next)
2326 count++;
2327 counts[count]++;
2328 }
2329 }
2330
2331 int i;
2332 for (i = counts.length - 1; i >= 0 && counts[i] == 0; i--) {
2333 }
2334 counts = Arrays.copyOf(counts, i + 1);
2335 return counts;
2336 }
2337
2338 private long heapSize() {
2339 long acc = objectSizeMaybe(this);
2340 acc += objectSizeMaybe(table);
2341
2342 XNode<K,V>[] tab = table;
2343 for (XNode<K,V> te : tab) {
2344 if (!te.isEmpty()) {
2345 for (Node<K, V> e = te.next; e != null; e = e.next)
2346 acc += objectSizeMaybe(e);
2347 }
2348 }
2349 return acc;
2350 }
2351
2352 private long objectSizeMaybe(Object o) {
2353 try {
2354 return (mObjectSize != null)
2355 ? (long)mObjectSize.invoke(null, o)
2356 : 0L;
2357 } catch (IllegalAccessException | InvocationTargetException e) {
2358 return 0L;
2359 }
2360 }
2361
2362 private static boolean hasObjectSize = false;
2363 private static Method mObjectSize = getObjectSizeMethod();
2364
2365 private static Method getObjectSizeMethod() {
2366 try {
2367 Method m = Objects.class.getDeclaredMethod("getObjectSize", Object.class);
2368 hasObjectSize = true;
2369 return m;
2370 } catch (NoSuchMethodException nsme) {
2371 return null;
2372 }
2373 }
2374
2375 }