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39 
40 #ifndef QV4SPARSEARRAY_H
41 #define QV4SPARSEARRAY_H
42 
43 //
44 //  W A R N I N G
45 //  -------------
46 //
47 // This file is not part of the Qt API.  It exists purely as an
48 // implementation detail.  This header file may change from version to
49 // version without notice, or even be removed.
50 //
51 // We mean it.
52 //
53 
54 #include "qv4global_p.h"
55 #include "qv4value_p.h"
56 #include <QtCore/qlist.h>
57 
58 //#define Q_MAP_DEBUG
59 #ifdef Q_MAP_DEBUG
60 #include <QtCore/qdebug.h>
61 #endif
62 
63 #include <new>
64 
65 QT_BEGIN_NAMESPACE
66 
67 namespace QV4 {
68 
69 struct SparseArray;
70 
71 struct SparseArrayNode
72 {
73     quintptr p;
74     SparseArrayNode *left;
75     SparseArrayNode *right;
76     uint size_left;
77     uint value;
78 
79     enum Color { Red = 0, Black = 1 };
80     enum { Mask = 3 }; // reserve the second bit as well
81 
82     const SparseArrayNode *nextNode() const;
nextNodeSparseArrayNode83     SparseArrayNode *nextNode() { return const_cast<SparseArrayNode *>(const_cast<const SparseArrayNode *>(this)->nextNode()); }
84     const SparseArrayNode *previousNode() const;
previousNodeSparseArrayNode85     SparseArrayNode *previousNode() { return const_cast<SparseArrayNode *>(const_cast<const SparseArrayNode *>(this)->previousNode()); }
86 
colorSparseArrayNode87     Color color() const { return Color(p & 1); }
setColorSparseArrayNode88     void setColor(Color c) { if (c == Black) p |= Black; else p &= ~Black; }
parentSparseArrayNode89     SparseArrayNode *parent() const { return reinterpret_cast<SparseArrayNode *>(p & ~Mask); }
setParentSparseArrayNode90     void setParent(SparseArrayNode *pp) { p = (p & Mask) | quintptr(pp); }
91 
keySparseArrayNode92     uint key() const {
93         uint k = size_left;
94         const SparseArrayNode *n = this;
95         while (SparseArrayNode *p = n->parent()) {
96             if (p && p->right == n)
97                 k += p->size_left;
98             n = p;
99         }
100         return k;
101     }
102 
103     SparseArrayNode *copy(SparseArray *d) const;
104 
105     SparseArrayNode *lowerBound(uint key);
106     SparseArrayNode *upperBound(uint key);
107 };
108 
109 
lowerBound(uint akey)110 inline SparseArrayNode *SparseArrayNode::lowerBound(uint akey)
111 {
112     SparseArrayNode *n = this;
113     SparseArrayNode *last = nullptr;
114     while (n) {
115         if (akey <= n->size_left) {
116             last = n;
117             n = n->left;
118         } else {
119             akey -= n->size_left;
120             n = n->right;
121         }
122     }
123     return last;
124 }
125 
126 
upperBound(uint akey)127 inline SparseArrayNode *SparseArrayNode::upperBound(uint akey)
128 {
129     SparseArrayNode *n = this;
130     SparseArrayNode *last = nullptr;
131     while (n) {
132         if (akey < n->size_left) {
133             last = n;
134             n = n->left;
135         } else {
136             akey -= n->size_left;
137             n = n->right;
138         }
139     }
140     return last;
141 }
142 
143 
144 
145 struct Q_QML_EXPORT SparseArray
146 {
147     SparseArray();
~SparseArraySparseArray148     ~SparseArray() {
149         if (root())
150             freeTree(header.left, Q_ALIGNOF(SparseArrayNode));
151     }
152 
153     SparseArray(const SparseArray &other);
154 
155     Value freeList;
156 private:
157     SparseArray &operator=(const SparseArray &other);
158 
159     int numEntries;
160     SparseArrayNode header;
161     SparseArrayNode *mostLeftNode;
162 
163     void rotateLeft(SparseArrayNode *x);
164     void rotateRight(SparseArrayNode *x);
165     void rebalance(SparseArrayNode *x);
166     void recalcMostLeftNode();
167 
rootSparseArray168     SparseArrayNode *root() const { return header.left; }
169 
170     void deleteNode(SparseArrayNode *z);
171 
172 
173 public:
174     SparseArrayNode *createNode(uint sl, SparseArrayNode *parent, bool left);
175     void freeTree(SparseArrayNode *root, int alignment);
176 
177     SparseArrayNode *findNode(uint akey) const;
178 
nEntriesSparseArray179     uint nEntries() const { return numEntries; }
180 
181     uint pop_front();
182     void push_front(uint at);
183     uint pop_back(uint len);
184     void push_back(uint at, uint len);
185 
186     QList<int> keys() const;
187 
endSparseArray188     const SparseArrayNode *end() const { return &header; }
endSparseArray189     SparseArrayNode *end() { return &header; }
beginSparseArray190     const SparseArrayNode *begin() const { if (root()) return mostLeftNode; return end(); }
beginSparseArray191     SparseArrayNode *begin() { if (root()) return mostLeftNode; return end(); }
192 
193     SparseArrayNode *erase(SparseArrayNode *n);
194 
195     SparseArrayNode *lowerBound(uint key);
196     const SparseArrayNode *lowerBound(uint key) const;
197     SparseArrayNode *upperBound(uint key);
198     const SparseArrayNode *upperBound(uint key) const;
199     SparseArrayNode *insert(uint akey);
200 
201     // STL compatibility
202     typedef uint key_type;
203     typedef int mapped_type;
204     typedef qptrdiff difference_type;
205     typedef int size_type;
206 
207 #ifdef Q_MAP_DEBUG
208     void dump() const;
209 #endif
210 };
211 
findNode(uint akey)212 inline SparseArrayNode *SparseArray::findNode(uint akey) const
213 {
214     SparseArrayNode *n = root();
215 
216     while (n) {
217         if (akey == n->size_left) {
218             return n;
219         } else if (akey < n->size_left) {
220             n = n->left;
221         } else {
222             akey -= n->size_left;
223             n = n->right;
224         }
225     }
226 
227     return nullptr;
228 }
229 
pop_front()230 inline uint SparseArray::pop_front()
231 {
232     uint idx = UINT_MAX ;
233 
234     SparseArrayNode *n = findNode(0);
235     if (n) {
236         idx = n->value;
237         deleteNode(n);
238         // adjust all size_left indices on the path to leftmost item by 1
239         SparseArrayNode *n = root();
240         while (n) {
241             n->size_left -= 1;
242             n = n->left;
243         }
244     }
245     return idx;
246 }
247 
push_front(uint value)248 inline void SparseArray::push_front(uint value)
249 {
250     // adjust all size_left indices on the path to leftmost item by 1
251     SparseArrayNode *n = root();
252     while (n) {
253         n->size_left += 1;
254         n = n->left;
255     }
256     n = insert(0);
257     n->value = value;
258 }
259 
pop_back(uint len)260 inline uint SparseArray::pop_back(uint len)
261 {
262     uint idx = UINT_MAX;
263     if (!len)
264         return idx;
265 
266     SparseArrayNode *n = findNode(len - 1);
267     if (n) {
268         idx = n->value;
269         deleteNode(n);
270     }
271     return idx;
272 }
273 
push_back(uint index,uint len)274 inline void SparseArray::push_back(uint index, uint len)
275 {
276     SparseArrayNode *n = insert(len);
277     n->value = index;
278 }
279 
280 #ifdef Q_MAP_DEBUG
dump()281 inline void SparseArray::dump() const
282 {
283     const SparseArrayNode *it = begin();
284     qDebug() << "map dump:";
285     while (it != end()) {
286         const SparseArrayNode *n = it;
287         int depth = 0;
288         while (n && n != root()) {
289             ++depth;
290             n = n->parent();
291         }
292         QByteArray space(4*depth, ' ');
293         qDebug() << space << (it->color() == SparseArrayNode::Red ? "Red  " : "Black") << it << it->size_left << it->left << it->right
294                  << it->key() << it->value;
295         it = it->nextNode();
296     }
297     qDebug() << "---------";
298 }
299 #endif
300 
301 
erase(SparseArrayNode * n)302 inline SparseArrayNode *SparseArray::erase(SparseArrayNode *n)
303 {
304     if (n == end())
305         return n;
306 
307     SparseArrayNode *next = n->nextNode();
308     deleteNode(n);
309     return next;
310 }
311 
keys()312 inline QList<int> SparseArray::keys() const
313 {
314     QList<int> res;
315     res.reserve(numEntries);
316     SparseArrayNode *n = mostLeftNode;
317     while (n != end()) {
318         res.append(n->key());
319         n = n->nextNode();
320     }
321     return res;
322 }
323 
lowerBound(uint akey)324 inline const SparseArrayNode *SparseArray::lowerBound(uint akey) const
325 {
326     const SparseArrayNode *lb = root()->lowerBound(akey);
327     if (!lb)
328         lb = end();
329     return lb;
330 }
331 
332 
lowerBound(uint akey)333 inline SparseArrayNode *SparseArray::lowerBound(uint akey)
334 {
335     SparseArrayNode *lb = root()->lowerBound(akey);
336     if (!lb)
337         lb = end();
338     return lb;
339 }
340 
341 
upperBound(uint akey)342 inline const SparseArrayNode *SparseArray::upperBound(uint akey) const
343 {
344     const SparseArrayNode *ub = root()->upperBound(akey);
345     if (!ub)
346         ub = end();
347     return ub;
348 }
349 
350 
upperBound(uint akey)351 inline SparseArrayNode *SparseArray::upperBound(uint akey)
352 {
353     SparseArrayNode *ub = root()->upperBound(akey);
354     if (!ub)
355         ub = end();
356     return ub;
357 }
358 
359 }
360 
361 QT_END_NAMESPACE
362 
363 #endif
364