summaryrefslogtreecommitdiffstats
path: root/src/corelib/tools/qhash.h
blob: 6a2d7bdd114d2ed452ec3e4666851f08f20684e2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Copyright (C) 2015 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com, author Marc Mutz <marc.mutz@kdab.com>
** Contact: https://www.qt.io/licensing/
**
** This file is part of the QtCore module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 3 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL3 included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 3 requirements
** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 2.0 or (at your option) the GNU General
** Public license version 3 or any later version approved by the KDE Free
** Qt Foundation. The licenses are as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
** included in the packaging of this file. Please review the following
** information to ensure the GNU General Public License requirements will
** be met: https://www.gnu.org/licenses/gpl-2.0.html and
** https://www.gnu.org/licenses/gpl-3.0.html.
**
** $QT_END_LICENSE$
**
****************************************************************************/

#ifndef QHASH_H
#define QHASH_H

#include <QtCore/qchar.h>
#include <QtCore/qiterator.h>
#include <QtCore/qlist.h>
#include <QtCore/qrefcount.h>
#include <QtCore/qhashfunctions.h>

#ifdef Q_COMPILER_INITIALIZER_LISTS
#include <initializer_list>
#endif

#if defined(Q_CC_MSVC)
#pragma warning( push )
#pragma warning( disable : 4311 ) // disable pointer truncation warning
#pragma warning( disable : 4127 ) // conditional expression is constant
#endif

QT_BEGIN_NAMESPACE

struct Q_CORE_EXPORT QHashData
{
    struct Node {
        Node *next;
        uint h;
    };

    Node *fakeNext;
    Node **buckets;
    QtPrivate::RefCount ref;
    int size;
    int nodeSize;
    short userNumBits;
    short numBits;
    int numBuckets;
    uint seed;
    uint sharable : 1;
    uint strictAlignment : 1;
    uint reserved : 30;

    void *allocateNode(int nodeAlign);
    void freeNode(void *node);
    QHashData *detach_helper(void (*node_duplicate)(Node *, void *), void (*node_delete)(Node *),
                             int nodeSize, int nodeAlign);
    bool willGrow();
    void hasShrunk();
    void rehash(int hint);
    void free_helper(void (*node_delete)(Node *));
    Node *firstNode();
#ifdef QT_QHASH_DEBUG
    void dump();
    void checkSanity();
#endif
    static Node *nextNode(Node *node);
    static Node *previousNode(Node *node);

    static const QHashData shared_null;
};

inline bool QHashData::willGrow()
{
    if (size >= numBuckets) {
        rehash(numBits + 1);
        return true;
    } else {
        return false;
    }
}

inline void QHashData::hasShrunk()
{
    if (size <= (numBuckets >> 3) && numBits > userNumBits) {
        QT_TRY {
            rehash(qMax(int(numBits) - 2, int(userNumBits)));
        } QT_CATCH(const std::bad_alloc &) {
            // ignore bad allocs - shrinking shouldn't throw. rehash is exception safe.
        }
    }
}

inline QHashData::Node *QHashData::firstNode()
{
    Node *e = reinterpret_cast<Node *>(this);
    Node **bucket = buckets;
    int n = numBuckets;
    while (n--) {
        if (*bucket != e)
            return *bucket;
        ++bucket;
    }
    return e;
}

struct QHashDummyValue
{
};

inline bool operator==(const QHashDummyValue & /* v1 */, const QHashDummyValue & /* v2 */)
{
    return true;
}

Q_DECLARE_TYPEINFO(QHashDummyValue, Q_MOVABLE_TYPE | Q_DUMMY_TYPE);

template <class Key, class T>
struct QHashNode
{
    QHashNode *next;
    const uint h;
    const Key key;
    T value;

    inline QHashNode(const Key &key0, const T &value0, uint hash, QHashNode *n)
        : next(n), h(hash), key(key0), value(value0) {}
    inline bool same_key(uint h0, const Key &key0) const { return h0 == h && key0 == key; }

private:
    Q_DISABLE_COPY(QHashNode)
};

// Specialize for QHashDummyValue in order to save some memory
template <class Key>
struct QHashNode<Key, QHashDummyValue>
{
    union {
        QHashNode *next;
        QHashDummyValue value;
    };
    const uint h;
    const Key key;

    inline QHashNode(const Key &key0, const QHashDummyValue &, uint hash, QHashNode *n)
        : next(n), h(hash), key(key0) {}
    inline bool same_key(uint h0, const Key &key0) const { return h0 == h && key0 == key; }

private:
    Q_DISABLE_COPY(QHashNode)
};


#if 0
// ###
// The introduction of the QHash random seed breaks this optimization, as it
// relies on qHash(int i) = i. If the hash value is salted, then the hash
// table becomes corrupted.
//
// A bit more research about whether it makes sense or not to salt integer
// keys (and in general keys whose hash value is easy to invert)
// is needed, or about how keep this optimization and the seed (f.i. by
// specializing QHash for integer values, and re-apply the seed during lookup).
//
// Be aware that such changes can easily be binary incompatible, and therefore
// cannot be made during the Qt 5 lifetime.
#define Q_HASH_DECLARE_INT_NODES(key_type) \
    template <class T> \
    struct QHashDummyNode<key_type, T> { \
        QHashDummyNode *next; \
        union { uint h; key_type key; }; \
\
        inline QHashDummyNode(key_type /* key0 */) {} \
    }; \
\
    template <class T> \
    struct QHashNode<key_type, T> { \
        QHashNode *next; \
        union { uint h; key_type key; }; \
        T value; \
\
        inline QHashNode(key_type /* key0 */) {} \
        inline QHashNode(key_type /* key0 */, const T &value0) : value(value0) {} \
        inline bool same_key(uint h0, key_type) const { return h0 == h; } \
    }

#if defined(Q_BYTE_ORDER) && Q_BYTE_ORDER == Q_LITTLE_ENDIAN
Q_HASH_DECLARE_INT_NODES(short);
Q_HASH_DECLARE_INT_NODES(ushort);
#endif
Q_HASH_DECLARE_INT_NODES(int);
Q_HASH_DECLARE_INT_NODES(uint);
#undef Q_HASH_DECLARE_INT_NODES
#endif // #if 0

template <class Key, class T>
class QHash
{
    typedef QHashNode<Key, T> Node;

    union {
        QHashData *d;
        QHashNode<Key, T> *e;
    };

    static inline Node *concrete(QHashData::Node *node) {
        return reinterpret_cast<Node *>(node);
    }

    static inline int alignOfNode() { return qMax<int>(sizeof(void*), Q_ALIGNOF(Node)); }

public:
    inline QHash() Q_DECL_NOTHROW : d(const_cast<QHashData *>(&QHashData::shared_null)) { }
#ifdef Q_COMPILER_INITIALIZER_LISTS
    inline QHash(std::initializer_list<std::pair<Key,T> > list)
        : d(const_cast<QHashData *>(&QHashData::shared_null))
    {
        reserve(int(list.size()));
        for (typename std::initializer_list<std::pair<Key,T> >::const_iterator it = list.begin(); it != list.end(); ++it)
            insert(it->first, it->second);
    }
#endif
    QHash(const QHash &other) : d(other.d) { d->ref.ref(); if (!d->sharable) detach(); }
    ~QHash() { if (!d->ref.deref()) freeData(d); }

    QHash &operator=(const QHash &other);
#ifdef Q_COMPILER_RVALUE_REFS
    QHash(QHash &&other) Q_DECL_NOTHROW : d(other.d) { other.d = const_cast<QHashData *>(&QHashData::shared_null); }
    QHash &operator=(QHash &&other) Q_DECL_NOTHROW
    { QHash moved(std::move(other)); swap(moved); return *this; }
#endif
    void swap(QHash &other) Q_DECL_NOTHROW { qSwap(d, other.d); }

    bool operator==(const QHash &other) const;
    bool operator!=(const QHash &other) const { return !(*this == other); }

    inline int size() const { return d->size; }

    inline bool isEmpty() const { return d->size == 0; }

    inline int capacity() const { return d->numBuckets; }
    void reserve(int size);
    inline void squeeze() { reserve(1); }

    inline void detach() { if (d->ref.isShared()) detach_helper(); }
    inline bool isDetached() const { return !d->ref.isShared(); }
#if !defined(QT_NO_UNSHARABLE_CONTAINERS)
    inline void setSharable(bool sharable) { if (!sharable) detach(); if (d != &QHashData::shared_null) d->sharable = sharable; }
#endif
    bool isSharedWith(const QHash &other) const { return d == other.d; }

    void clear();

    int remove(const Key &key);
    T take(const Key &key);

    bool contains(const Key &key) const;
    const Key key(const T &value) const;
    const Key key(const T &value, const Key &defaultKey) const;
    const T value(const Key &key) const;
    const T value(const Key &key, const T &defaultValue) const;
    T &operator[](const Key &key);
    const T operator[](const Key &key) const;

    QList<Key> uniqueKeys() const;
    QList<Key> keys() const;
    QList<Key> keys(const T &value) const;
    QList<T> values() const;
    QList<T> values(const Key &key) const;
    int count(const Key &key) const;

    class const_iterator;

    class iterator
    {
        friend class const_iterator;
        friend class QHash<Key, T>;
        friend class QSet<Key>;
        QHashData::Node *i;

    public:
        typedef std::bidirectional_iterator_tag iterator_category;
        typedef qptrdiff difference_type;
        typedef T value_type;
        typedef T *pointer;
        typedef T &reference;

        inline iterator() : i(Q_NULLPTR) { }
        explicit inline iterator(void *node) : i(reinterpret_cast<QHashData::Node *>(node)) { }

        inline const Key &key() const { return concrete(i)->key; }
        inline T &value() const { return concrete(i)->value; }
        inline T &operator*() const { return concrete(i)->value; }
        inline T *operator->() const { return &concrete(i)->value; }
        inline bool operator==(const iterator &o) const { return i == o.i; }
        inline bool operator!=(const iterator &o) const { return i != o.i; }

        inline iterator &operator++() {
            i = QHashData::nextNode(i);
            return *this;
        }
        inline iterator operator++(int) {
            iterator r = *this;
            i = QHashData::nextNode(i);
            return r;
        }
        inline iterator &operator--() {
            i = QHashData::previousNode(i);
            return *this;
        }
        inline iterator operator--(int) {
            iterator r = *this;
            i = QHashData::previousNode(i);
            return r;
        }
        inline iterator operator+(int j) const
        { iterator r = *this; if (j > 0) while (j--) ++r; else while (j++) --r; return r; }
        inline iterator operator-(int j) const { return operator+(-j); }
        inline iterator &operator+=(int j) { return *this = *this + j; }
        inline iterator &operator-=(int j) { return *this = *this - j; }

#ifndef QT_STRICT_ITERATORS
    public:
        inline bool operator==(const const_iterator &o) const
            { return i == o.i; }
        inline bool operator!=(const const_iterator &o) const
            { return i != o.i; }
#endif
    };
    friend class iterator;

    class const_iterator
    {
        friend class iterator;
        friend class QHash<Key, T>;
        friend class QSet<Key>;
        QHashData::Node *i;

    public:
        typedef std::bidirectional_iterator_tag iterator_category;
        typedef qptrdiff difference_type;
        typedef T value_type;
        typedef const T *pointer;
        typedef const T &reference;

        inline const_iterator() : i(Q_NULLPTR) { }
        explicit inline const_iterator(void *node)
            : i(reinterpret_cast<QHashData::Node *>(node)) { }
#ifdef QT_STRICT_ITERATORS
        explicit inline const_iterator(const iterator &o)
#else
        inline const_iterator(const iterator &o)
#endif
        { i = o.i; }

        inline const Key &key() const { return concrete(i)->key; }
        inline const T &value() const { return concrete(i)->value; }
        inline const T &operator*() const { return concrete(i)->value; }
        inline const T *operator->() const { return &concrete(i)->value; }
        inline bool operator==(const const_iterator &o) const { return i == o.i; }
        inline bool operator!=(const const_iterator &o) const { return i != o.i; }

        inline const_iterator &operator++() {
            i = QHashData::nextNode(i);
            return *this;
        }
        inline const_iterator operator++(int) {
            const_iterator r = *this;
            i = QHashData::nextNode(i);
            return r;
        }
        inline const_iterator &operator--() {
            i = QHashData::previousNode(i);
            return *this;
        }
        inline const_iterator operator--(int) {
            const_iterator r = *this;
            i = QHashData::previousNode(i);
            return r;
        }
        inline const_iterator operator+(int j) const
        { const_iterator r = *this; if (j > 0) while (j--) ++r; else while (j++) --r; return r; }
        inline const_iterator operator-(int j) const { return operator+(-j); }
        inline const_iterator &operator+=(int j) { return *this = *this + j; }
        inline const_iterator &operator-=(int j) { return *this = *this - j; }

        // ### Qt 5: not sure this is necessary anymore
#ifdef QT_STRICT_ITERATORS
    private:
        inline bool operator==(const iterator &o) const { return operator==(const_iterator(o)); }
        inline bool operator!=(const iterator &o) const { return operator!=(const_iterator(o)); }
#endif
    };
    friend class const_iterator;

    class key_iterator
    {
        const_iterator i;

    public:
        typedef typename const_iterator::iterator_category iterator_category;
        typedef typename const_iterator::difference_type difference_type;
        typedef Key value_type;
        typedef const Key *pointer;
        typedef const Key &reference;

        explicit key_iterator(const_iterator o) : i(o) { }

        const Key &operator*() const { return i.key(); }
        const Key *operator->() const { return &i.key(); }
        bool operator==(key_iterator o) const { return i == o.i; }
        bool operator!=(key_iterator o) const { return i != o.i; }

        inline key_iterator &operator++() { ++i; return *this; }
        inline key_iterator operator++(int) { return key_iterator(i++);}
        inline key_iterator &operator--() { --i; return *this; }
        inline key_iterator operator--(int) { return key_iterator(i--); }
        const_iterator base() const { return i; }
    };

    // STL style
    inline iterator begin() { detach(); return iterator(d->firstNode()); }
    inline const_iterator begin() const { return const_iterator(d->firstNode()); }
    inline const_iterator cbegin() const { return const_iterator(d->firstNode()); }
    inline const_iterator constBegin() const { return const_iterator(d->firstNode()); }
    inline iterator end() { detach(); return iterator(e); }
    inline const_iterator end() const { return const_iterator(e); }
    inline const_iterator cend() const { return const_iterator(e); }
    inline const_iterator constEnd() const { return const_iterator(e); }
    inline key_iterator keyBegin() const { return key_iterator(begin()); }
    inline key_iterator keyEnd() const { return key_iterator(end()); }

    QPair<iterator, iterator> equal_range(const Key &key);
    QPair<const_iterator, const_iterator> equal_range(const Key &key) const Q_DECL_NOTHROW;
    iterator erase(iterator it) { return erase(const_iterator(it.i)); }
    iterator erase(const_iterator it);

    // more Qt
    typedef iterator Iterator;
    typedef const_iterator ConstIterator;
    inline int count() const { return d->size; }
    iterator find(const Key &key);
    const_iterator find(const Key &key) const;
    const_iterator constFind(const Key &key) const;
    iterator insert(const Key &key, const T &value);
    iterator insertMulti(const Key &key, const T &value);
    QHash &unite(const QHash &other);

    // STL compatibility
    typedef T mapped_type;
    typedef Key key_type;
    typedef qptrdiff difference_type;
    typedef int size_type;

    inline bool empty() const { return isEmpty(); }

#ifdef QT_QHASH_DEBUG
    inline void dump() const { d->dump(); }
    inline void checkSanity() const { d->checkSanity(); }
#endif

private:
    void detach_helper();
    void freeData(QHashData *d);
    Node **findNode(const Key &key, uint *hp = Q_NULLPTR) const;
    Node **findNode(const Key &key, uint h) const;
    Node *createNode(uint h, const Key &key, const T &value, Node **nextNode);
    void deleteNode(Node *node);
    static void deleteNode2(QHashData::Node *node);

    static void duplicateNode(QHashData::Node *originalNode, void *newNode);

    bool isValidIterator(const iterator &it) const Q_DECL_NOTHROW
    { return isValidNode(it.i); }
    bool isValidIterator(const const_iterator &it) const Q_DECL_NOTHROW
    { return isValidNode(it.i); }
    bool isValidNode(QHashData::Node *node) const Q_DECL_NOTHROW
    {
#if defined(QT_DEBUG) && !defined(Q_HASH_NO_ITERATOR_DEBUG)
        while (node->next)
            node = node->next;
        return (static_cast<void *>(node) == d);
#else
        Q_UNUSED(node);
        return true;
#endif
    }
    friend class QSet<Key>;
};


template <class Key, class T>
Q_INLINE_TEMPLATE void QHash<Key, T>::deleteNode(Node *node)
{
    deleteNode2(reinterpret_cast<QHashData::Node*>(node));
    d->freeNode(node);
}

template <class Key, class T>
Q_INLINE_TEMPLATE void QHash<Key, T>::deleteNode2(QHashData::Node *node)
{
#ifdef Q_CC_BOR
    concrete(node)->~QHashNode<Key, T>();
#else
    concrete(node)->~Node();
#endif
}

template <class Key, class T>
Q_INLINE_TEMPLATE void QHash<Key, T>::duplicateNode(QHashData::Node *node, void *newNode)
{
    Node *concreteNode = concrete(node);
    new (newNode) Node(concreteNode->key, concreteNode->value, concreteNode->h, Q_NULLPTR);
}

template <class Key, class T>
Q_INLINE_TEMPLATE typename QHash<Key, T>::Node *
QHash<Key, T>::createNode(uint ah, const Key &akey, const T &avalue, Node **anextNode)
{
    Node *node = new (d->allocateNode(alignOfNode())) Node(akey, avalue, ah, *anextNode);
    *anextNode = node;
    ++d->size;
    return node;
}

template <class Key, class T>
Q_INLINE_TEMPLATE QHash<Key, T> &QHash<Key, T>::unite(const QHash &other)
{
    if (d == &QHashData::shared_null) {
        *this = other;
    } else {
        QHash copy(other);
        const_iterator it = copy.constEnd();
        while (it != copy.constBegin()) {
            --it;
            insertMulti(it.key(), it.value());
        }
    }
    return *this;
}

template <class Key, class T>
Q_OUTOFLINE_TEMPLATE void QHash<Key, T>::freeData(QHashData *x)
{
    x->free_helper(deleteNode2);
}

template <class Key, class T>
Q_INLINE_TEMPLATE void QHash<Key, T>::clear()
{
    *this = QHash();
}

template <class Key, class T>
Q_OUTOFLINE_TEMPLATE void QHash<Key, T>::detach_helper()
{
    QHashData *x = d->detach_helper(duplicateNode, deleteNode2, sizeof(Node), alignOfNode());
    if (!d->ref.deref())
        freeData(d);
    d = x;
}

template <class Key, class T>
Q_INLINE_TEMPLATE QHash<Key, T> &QHash<Key, T>::operator=(const QHash &other)
{
    if (d != other.d) {
        QHashData *o = other.d;
        o->ref.ref();
        if (!d->ref.deref())
            freeData(d);
        d = o;
        if (!d->sharable)
            detach_helper();
    }
    return *this;
}

template <class Key, class T>
Q_INLINE_TEMPLATE const T QHash<Key, T>::value(const Key &akey) const
{
    Node *node;
    if (d->size == 0 || (node = *findNode(akey)) == e) {
        return T();
    } else {
        return node->value;
    }
}

template <class Key, class T>
Q_INLINE_TEMPLATE const T QHash<Key, T>::value(const Key &akey, const T &adefaultValue) const
{
    Node *node;
    if (d->size == 0 || (node = *findNode(akey)) == e) {
        return adefaultValue;
    } else {
        return node->value;
    }
}

template <class Key, class T>
Q_OUTOFLINE_TEMPLATE QList<Key> QHash<Key, T>::uniqueKeys() const
{
    QList<Key> res;
    res.reserve(size()); // May be too much, but assume short lifetime
    const_iterator i = begin();
    if (i != end()) {
        for (;;) {
            const Key &aKey = i.key();
            res.append(aKey);
            do {
                if (++i == end())
                    goto break_out_of_outer_loop;
            } while (aKey == i.key());
        }
    }
break_out_of_outer_loop:
    return res;
}

template <class Key, class T>
Q_OUTOFLINE_TEMPLATE QList<Key> QHash<Key, T>::keys() const
{
    QList<Key> res;
    res.reserve(size());
    const_iterator i = begin();
    while (i != end()) {
        res.append(i.key());
        ++i;
    }
    return res;
}

template <class Key, class T>
Q_OUTOFLINE_TEMPLATE QList<Key> QHash<Key, T>::keys(const T &avalue) const
{
    QList<Key> res;
    const_iterator i = begin();
    while (i != end()) {
        if (i.value() == avalue)
            res.append(i.key());
        ++i;
    }
    return res;
}

template <class Key, class T>
Q_OUTOFLINE_TEMPLATE const Key QHash<Key, T>::key(const T &avalue) const
{
    return key(avalue, Key());
}

template <class Key, class T>
Q_OUTOFLINE_TEMPLATE const Key QHash<Key, T>::key(const T &avalue, const Key &defaultValue) const
{
    const_iterator i = begin();
    while (i != end()) {
        if (i.value() == avalue)
            return i.key();
        ++i;
    }

    return defaultValue;
}

template <class Key, class T>
Q_OUTOFLINE_TEMPLATE QList<T> QHash<Key, T>::values() const
{
    QList<T> res;
    res.reserve(size());
    const_iterator i = begin();
    while (i != end()) {
        res.append(i.value());
        ++i;
    }
    return res;
}

template <class Key, class T>
Q_OUTOFLINE_TEMPLATE QList<T> QHash<Key, T>::values(const Key &akey) const
{
    QList<T> res;
    Node *node = *findNode(akey);
    if (node != e) {
        do {
            res.append(node->value);
        } while ((node = node->next) != e && node->key == akey);
    }
    return res;
}

template <class Key, class T>
Q_OUTOFLINE_TEMPLATE int QHash<Key, T>::count(const Key &akey) const
{
    int cnt = 0;
    Node *node = *findNode(akey);
    if (node != e) {
        do {
            ++cnt;
        } while ((node = node->next) != e && node->key == akey);
    }
    return cnt;
}

template <class Key, class T>
Q_INLINE_TEMPLATE const T QHash<Key, T>::operator[](const Key &akey) const
{
    return value(akey);
}

template <class Key, class T>
Q_INLINE_TEMPLATE T &QHash<Key, T>::operator[](const Key &akey)
{
    detach();

    uint h;
    Node **node = findNode(akey, &h);
    if (*node == e) {
        if (d->willGrow())
            node = findNode(akey, &h);
        return createNode(h, akey, T(), node)->value;
    }
    return (*node)->value;
}

template <class Key, class T>
Q_INLINE_TEMPLATE typename QHash<Key, T>::iterator QHash<Key, T>::insert(const Key &akey,
                                                                         const T &avalue)
{
    detach();

    uint h;
    Node **node = findNode(akey, &h);
    if (*node == e) {
        if (d->willGrow())
            node = findNode(akey, &h);
        return iterator(createNode(h, akey, avalue, node));
    }

    if (!QtPrivate::is_same<T, QHashDummyValue>::value)
        (*node)->value = avalue;
    return iterator(*node);
}

template <class Key, class T>
Q_INLINE_TEMPLATE typename QHash<Key, T>::iterator QHash<Key, T>::insertMulti(const Key &akey,
                                                                              const T &avalue)
{
    detach();
    d->willGrow();

    uint h;
    Node **nextNode = findNode(akey, &h);
    return iterator(createNode(h, akey, avalue, nextNode));
}

template <class Key, class T>
Q_OUTOFLINE_TEMPLATE int QHash<Key, T>::remove(const Key &akey)
{
    if (isEmpty()) // prevents detaching shared null
        return 0;
    detach();

    int oldSize = d->size;
    Node **node = findNode(akey);
    if (*node != e) {
        bool deleteNext = true;
        do {
            Node *next = (*node)->next;
            deleteNext = (next != e && next->key == (*node)->key);
            deleteNode(*node);
            *node = next;
            --d->size;
        } while (deleteNext);
        d->hasShrunk();
    }
    return oldSize - d->size;
}

template <class Key, class T>
Q_OUTOFLINE_TEMPLATE T QHash<Key, T>::take(const Key &akey)
{
    if (isEmpty()) // prevents detaching shared null
        return T();
    detach();

    Node **node = findNode(akey);
    if (*node != e) {
        T t = (*node)->value;
        Node *next = (*node)->next;
        deleteNode(*node);
        *node = next;
        --d->size;
        d->hasShrunk();
        return t;
    }
    return T();
}

template <class Key, class T>
Q_OUTOFLINE_TEMPLATE typename QHash<Key, T>::iterator QHash<Key, T>::erase(const_iterator it)
{
    Q_ASSERT_X(isValidIterator(it), "QHash::erase", "The specified iterator argument 'it' is invalid");

    if (it == const_iterator(e))
        return iterator(it.i);

    if (d->ref.isShared()) {
        // save 'it' across the detach:
        int bucketNum = (it.i->h % d->numBuckets);
        const_iterator bucketIterator(*(d->buckets + bucketNum));
        int stepsFromBucketStartToIte = 0;
        while (bucketIterator != it) {
            ++stepsFromBucketStartToIte;
            ++bucketIterator;
        }
        detach();
        it = const_iterator(*(d->buckets + bucketNum));
        while (stepsFromBucketStartToIte > 0) {
            --stepsFromBucketStartToIte;
            ++it;
        }
    }

    iterator ret(it.i);
    ++ret;

    Node *node = concrete(it.i);
    Node **node_ptr = reinterpret_cast<Node **>(&d->buckets[node->h % d->numBuckets]);
    while (*node_ptr != node)
        node_ptr = &(*node_ptr)->next;
    *node_ptr = node->next;
    deleteNode(node);
    --d->size;
    return ret;
}

template <class Key, class T>
Q_INLINE_TEMPLATE void QHash<Key, T>::reserve(int asize)
{
    detach();
    d->rehash(-qMax(asize, 1));
}

template <class Key, class T>
Q_INLINE_TEMPLATE typename QHash<Key, T>::const_iterator QHash<Key, T>::find(const Key &akey) const
{
    return const_iterator(*findNode(akey));
}

template <class Key, class T>
Q_INLINE_TEMPLATE typename QHash<Key, T>::const_iterator QHash<Key, T>::constFind(const Key &akey) const
{
    return const_iterator(*findNode(akey));
}

template <class Key, class T>
Q_INLINE_TEMPLATE typename QHash<Key, T>::iterator QHash<Key, T>::find(const Key &akey)
{
    detach();
    return iterator(*findNode(akey));
}

template <class Key, class T>
Q_INLINE_TEMPLATE bool QHash<Key, T>::contains(const Key &akey) const
{
    return *findNode(akey) != e;
}

template <class Key, class T>
Q_OUTOFLINE_TEMPLATE typename QHash<Key, T>::Node **QHash<Key, T>::findNode(const Key &akey, uint h) const
{
    Node **node;

    if (d->numBuckets) {
        node = reinterpret_cast<Node **>(&d->buckets[h % d->numBuckets]);
        Q_ASSERT(*node == e || (*node)->next);
        while (*node != e && !(*node)->same_key(h, akey))
            node = &(*node)->next;
    } else {
        node = const_cast<Node **>(reinterpret_cast<const Node * const *>(&e));
    }
    return node;
}

template <class Key, class T>
Q_OUTOFLINE_TEMPLATE typename QHash<Key, T>::Node **QHash<Key, T>::findNode(const Key &akey,
                                                                            uint *ahp) const
{
    uint h = 0;

    if (d->numBuckets || ahp) {
        h = qHash(akey, d->seed);
        if (ahp)
            *ahp = h;
    }
    return findNode(akey, h);
}

template <class Key, class T>
Q_OUTOFLINE_TEMPLATE bool QHash<Key, T>::operator==(const QHash &other) const
{
    if (size() != other.size())
        return false;
    if (d == other.d)
        return true;

    const_iterator it = begin();

    while (it != end()) {
        const Key &akey = it.key();

        const_iterator it2 = other.find(akey);
        do {
            if (it2 == other.end() || !(it2.key() == akey))
                return false;
            if (!(it.value() == it2.value()))
                return false;
            ++it;
            ++it2;
        } while (it != end() && it.key() == akey);
    }
    return true;
}

template <class Key, class T>
QPair<typename QHash<Key, T>::iterator, typename QHash<Key, T>::iterator> QHash<Key, T>::equal_range(const Key &akey)
{
    detach();
    auto pair = qAsConst(*this).equal_range(akey);
    return qMakePair(iterator(pair.first.i), iterator(pair.second.i));
}

template <class Key, class T>
QPair<typename QHash<Key, T>::const_iterator, typename QHash<Key, T>::const_iterator> QHash<Key, T>::equal_range(const Key &akey) const Q_DECL_NOTHROW
{
    uint h;
    Node *node = *findNode(akey, &h);
    const_iterator firstIt = const_iterator(node);

    if (node != e) {
        // equal keys must hash to the same value and so they all
        // end up in the same bucket. So we can use node->next,
        // which only works within a bucket, instead of (out-of-line)
        // QHashData::nextNode()
        while (node->next != e && node->next->key == akey)
            node = node->next;

        // 'node' may be the last node in the bucket. To produce the end iterator, we'd
        // need to enter the next bucket in this case, so we need to use
        // QHashData::nextNode() here, which, unlike node->next above, can move between
        // buckets.
        node = concrete(QHashData::nextNode(reinterpret_cast<QHashData::Node *>(node)));
    }

    return qMakePair(firstIt, const_iterator(node));
}

template <class Key, class T>
class QMultiHash : public QHash<Key, T>
{
public:
    QMultiHash() Q_DECL_NOTHROW {}
#ifdef Q_COMPILER_INITIALIZER_LISTS
    inline QMultiHash(std::initializer_list<std::pair<Key,T> > list)
    {
        this->reserve(int(list.size()));
        for (typename std::initializer_list<std::pair<Key,T> >::const_iterator it = list.begin(); it != list.end(); ++it)
            insert(it->first, it->second);
    }
#endif
    // compiler-generated copy/move ctors/assignment operators are fine!
    // compiler-generated destructor is fine!

    QMultiHash(const QHash<Key, T> &other) : QHash<Key, T>(other) {}
#ifdef Q_COMPILER_RVALUE_REFS
    QMultiHash(QHash<Key, T> &&other) Q_DECL_NOTHROW : QHash<Key, T>(std::move(other)) {}
#endif
    void swap(QMultiHash &other) Q_DECL_NOTHROW { QHash<Key, T>::swap(other); } // prevent QMultiHash<->QHash swaps

    inline typename QHash<Key, T>::iterator replace(const Key &key, const T &value)
    { return QHash<Key, T>::insert(key, value); }

    inline typename QHash<Key, T>::iterator insert(const Key &key, const T &value)
    { return QHash<Key, T>::insertMulti(key, value); }

    inline QMultiHash &operator+=(const QMultiHash &other)
    { this->unite(other); return *this; }
    inline QMultiHash operator+(const QMultiHash &other) const
    { QMultiHash result = *this; result += other; return result; }

    using QHash<Key, T>::contains;
    using QHash<Key, T>::remove;
    using QHash<Key, T>::count;
    using QHash<Key, T>::find;
    using QHash<Key, T>::constFind;

    bool contains(const Key &key, const T &value) const;

    int remove(const Key &key, const T &value);

    int count(const Key &key, const T &value) const;

    typename QHash<Key, T>::iterator find(const Key &key, const T &value) {
        typename QHash<Key, T>::iterator i(find(key));
        typename QHash<Key, T>::iterator end(this->end());
        while (i != end && i.key() == key) {
            if (i.value() == value)
                return i;
            ++i;
        }
        return end;
    }
    typename QHash<Key, T>::const_iterator find(const Key &key, const T &value) const {
        typename QHash<Key, T>::const_iterator i(constFind(key));
        typename QHash<Key, T>::const_iterator end(QHash<Key, T>::constEnd());
        while (i != end && i.key() == key) {
            if (i.value() == value)
                return i;
            ++i;
        }
        return end;
    }
    typename QHash<Key, T>::const_iterator constFind(const Key &key, const T &value) const
        { return find(key, value); }
private:
    T &operator[](const Key &key);
    const T operator[](const Key &key) const;
};

template <class Key, class T>
Q_INLINE_TEMPLATE bool QMultiHash<Key, T>::contains(const Key &key, const T &value) const
{
    return constFind(key, value) != QHash<Key, T>::constEnd();
}

template <class Key, class T>
Q_INLINE_TEMPLATE int QMultiHash<Key, T>::remove(const Key &key, const T &value)
{
    int n = 0;
    typename QHash<Key, T>::iterator i(find(key));
    typename QHash<Key, T>::iterator end(QHash<Key, T>::end());
    while (i != end && i.key() == key) {
        if (i.value() == value) {
            i = this->erase(i);
            ++n;
        } else {
            ++i;
        }
    }
    return n;
}

template <class Key, class T>
Q_INLINE_TEMPLATE int QMultiHash<Key, T>::count(const Key &key, const T &value) const
{
    int n = 0;
    typename QHash<Key, T>::const_iterator i(constFind(key));
    typename QHash<Key, T>::const_iterator end(QHash<Key, T>::constEnd());
    while (i != end && i.key() == key) {
        if (i.value() == value)
            ++n;
        ++i;
    }
    return n;
}

Q_DECLARE_ASSOCIATIVE_ITERATOR(Hash)
Q_DECLARE_MUTABLE_ASSOCIATIVE_ITERATOR(Hash)

template <class Key, class T>
uint qHash(const QHash<Key, T> &key, uint seed = 0)
    Q_DECL_NOEXCEPT_EXPR(noexcept(qHash(std::declval<Key&>())) && noexcept(qHash(std::declval<T&>())))
{
    QtPrivate::QHashCombineCommutative hash;
    for (auto it = key.begin(), end = key.end(); it != end; ++it) {
        const Key &k = it.key();
        const T   &v = it.value();
        seed = hash(seed, std::pair<const Key&, const T&>(k, v));
    }
    return seed;
}

template <class Key, class T>
inline uint qHash(const QMultiHash<Key, T> &key, uint seed = 0)
    Q_DECL_NOEXCEPT_EXPR(noexcept(qHash(std::declval<Key&>())) && noexcept(qHash(std::declval<T&>())))
{
    const QHash<Key, T> &key2 = key;
    return qHash(key2, seed);
}

QT_END_NAMESPACE

#if defined(Q_CC_MSVC)
#pragma warning( pop )
#endif

#endif // QHASH_H