1 /*
2 * Copyright © 2012,2017 Google, Inc.
3 *
4 * This is part of HarfBuzz, a text shaping library.
5 *
6 * Permission is hereby granted, without written agreement and without
7 * license or royalty fees, to use, copy, modify, and distribute this
8 * software and its documentation for any purpose, provided that the
9 * above copyright notice and the following two paragraphs appear in
10 * all copies of this software.
11 *
12 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
13 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
14 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
15 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
16 * DAMAGE.
17 *
18 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
19 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
20 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
21 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
22 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
23 *
24 * Google Author(s): Behdad Esfahbod
25 */
26
27 #ifndef HB_SET_PRIVATE_HH
28 #define HB_SET_PRIVATE_HH
29
30 #include "hb-private.hh"
31 #include "hb-object-private.hh"
32
33
34 /*
35 * hb_set_t
36 */
37
38 struct hb_set_t
39 {
40 struct page_map_t
41 {
42 inline int cmp (const page_map_t *o) const { return (int) o->major - (int) major; }
43
44 uint32_t major;
45 uint32_t index;
46 };
47
48 struct page_t
49 {
50 inline void init (void) {
51 memset (&v, 0, sizeof (v));
52 }
53
54 inline unsigned int len (void) const
55 { return ARRAY_LENGTH_CONST (v); }
56
57 inline bool is_empty (void) const
58 {
59 for (unsigned int i = 0; i < len (); i++)
60 if (v[i])
61 return false;
62 return true;
63 }
64
65 inline void add (hb_codepoint_t g) { elt (g) |= mask (g); }
66 inline void del (hb_codepoint_t g) { elt (g) &= ~mask (g); }
67 inline bool has (hb_codepoint_t g) const { return !!(elt (g) & mask (g)); }
68
69 inline bool is_equal (const page_t *other) const
70 {
71 return 0 == memcmp (&v, &other->v, sizeof (v));
72 }
73
74 inline unsigned int get_population (void) const
75 {
76 unsigned int pop = 0;
77 for (unsigned int i = 0; i < len (); i++)
78 pop += _hb_popcount (v[i]);
79 return pop;
80 }
81
82 inline bool next (hb_codepoint_t *codepoint) const
83 {
84 unsigned int m = (*codepoint + 1) & MASK;
85 if (!m)
86 {
87 *codepoint = INVALID;
88 return false;
89 }
90 unsigned int i = m / ELT_BITS;
91 unsigned int j = m & ELT_MASK;
92
93 for (; j < ELT_BITS; j++)
94 if (v[i] & (elt_t (1) << j))
95 goto found;
96 for (i++; i < len (); i++)
97 if (v[i])
98 for (j = 0; j < ELT_BITS; j++)
99 if (v[i] & (elt_t (1) << j))
100 goto found;
101
102 *codepoint = INVALID;
103 return false;
104
105 found:
106 *codepoint = i * ELT_BITS + j;
107 return true;
108 }
109 inline hb_codepoint_t get_min (void) const
110 {
111 for (unsigned int i = 0; i < len (); i++)
112 if (v[i])
113 {
114 elt_t e = v[i];
115 for (unsigned int j = 0; j < ELT_BITS; j++)
116 if (e & (elt_t (1) << j))
117 return i * ELT_BITS + j;
118 }
119 return INVALID;
120 }
121 inline hb_codepoint_t get_max (void) const
122 {
123 for (int i = len () - 1; i >= 0; i--)
124 if (v[i])
125 {
126 elt_t e = v[i];
127 for (int j = ELT_BITS - 1; j >= 0; j--)
128 if (e & (elt_t (1) << j))
129 return i * ELT_BITS + j;
130 }
131 return 0;
132 }
133
134 static const unsigned int PAGE_BITS = 512; /* Use to tune. */
135 static_assert ((PAGE_BITS & ((PAGE_BITS) - 1)) == 0, "");
136
137 typedef uint64_t elt_t;
138
139 #if 0 && HAVE_VECTOR_SIZE
140 /* The vectorized version does not work with clang as non-const
141 * elt() errs "non-const reference cannot bind to vector element". */
142 typedef elt_t vector_t __attribute__((vector_size (PAGE_BITS / 8)));
143 #else
144 typedef hb_vector_size_t<elt_t, PAGE_BITS / 8> vector_t;
145 #endif
146
147 vector_t v;
148
149 static const unsigned int ELT_BITS = sizeof (elt_t) * 8;
150 static const unsigned int ELT_MASK = ELT_BITS - 1;
151 static const unsigned int BITS = sizeof (vector_t) * 8;
152 static const unsigned int MASK = BITS - 1;
153 static_assert (PAGE_BITS == BITS, "");
154
155 elt_t &elt (hb_codepoint_t g) { return v[(g & MASK) / ELT_BITS]; }
156 elt_t const &elt (hb_codepoint_t g) const { return v[(g & MASK) / ELT_BITS]; }
157 elt_t mask (hb_codepoint_t g) const { return elt_t (1) << (g & ELT_MASK); }
158 };
159 static_assert (page_t::PAGE_BITS == sizeof (page_t) * 8, "");
160
161 hb_object_header_t header;
162 ASSERT_POD ();
163 bool in_error;
164 hb_prealloced_array_t<page_map_t, 8> page_map;
165 hb_prealloced_array_t<page_t, 8> pages;
166
167 inline bool resize (unsigned int count)
168 {
169 if (unlikely (in_error)) return false;
170 if (!pages.resize (count) || !page_map.resize (count))
171 {
172 pages.resize (page_map.len);
173 in_error = true;
174 return false;
175 }
176 return true;
177 }
178
179 inline void clear (void) {
180 if (unlikely (hb_object_is_inert (this)))
181 return;
182 in_error = false;
183 page_map.resize (0);
184 pages.resize (0);
185 }
186 inline bool is_empty (void) const {
187 unsigned int count = pages.len;
188 for (unsigned int i = 0; i < count; i++)
189 if (!pages[i].is_empty ())
190 return false;
191 return true;
192 }
193
194 inline void add (hb_codepoint_t g)
195 {
196 if (unlikely (in_error)) return;
197 if (unlikely (g == INVALID)) return;
198 page_t *page = page_for_insert (g);
199 if (!page)
200 return;
201 page->add (g);
202 }
203 inline void add_range (hb_codepoint_t a, hb_codepoint_t b)
204 {
205 if (unlikely (in_error)) return;
206 /* TODO Speedup */
207 for (unsigned int i = a; i < b + 1; i++)
208 add (i);
209 }
210 inline void del (hb_codepoint_t g)
211 {
212 if (unlikely (in_error)) return;
213 page_t *p = page_for (g);
214 if (!p)
215 return;
216 p->del (g);
217 }
218 inline void del_range (hb_codepoint_t a, hb_codepoint_t b)
219 {
220 if (unlikely (in_error)) return;
221 for (unsigned int i = a; i < b + 1; i++)
222 del (i);
223 }
224 inline bool has (hb_codepoint_t g) const
225 {
226 const page_t *p = page_for (g);
227 if (!p)
228 return false;
229 return p->has (g);
230 }
231 inline bool intersects (hb_codepoint_t first,
232 hb_codepoint_t last) const
233 {
234 hb_codepoint_t c = first - 1;
235 return next (&c) && c <= last;
236 }
237 inline void set (const hb_set_t *other)
238 {
239 if (unlikely (in_error)) return;
240 unsigned int count = other->pages.len;
241 if (!resize (count))
242 return;
243
244 memcpy (pages.array, other->pages.array, count * sizeof (pages.array[0]));
245 memcpy (page_map.array, other->page_map.array, count * sizeof (page_map.array[0]));
246 }
247
248 inline bool is_equal (const hb_set_t *other) const
249 {
250 unsigned int na = pages.len;
251 unsigned int nb = other->pages.len;
252
253 unsigned int a = 0, b = 0;
254 for (; a < na && b < nb; )
255 {
256 if (page_at (a).is_empty ()) { a++; continue; }
257 if (other->page_at (b).is_empty ()) { b++; continue; }
258 if (page_map[a].major != other->page_map[b].major ||
259 !page_at (a).is_equal (&other->page_at (b)))
260 return false;
261 a++;
262 b++;
263 }
264 for (; a < na; a++)
265 if (!page_at (a).is_empty ()) { return false; }
266 for (; b < nb; b++)
267 if (!other->page_at (b).is_empty ()) { return false; }
268
269 return true;
270 }
271
272 template <class Op>
273 inline void process (const hb_set_t *other)
274 {
275 if (unlikely (in_error)) return;
276
277 unsigned int na = pages.len;
278 unsigned int nb = other->pages.len;
279
280 unsigned int count = 0;
281 unsigned int a = 0, b = 0;
282 for (; a < na && b < nb; )
283 {
284 if (page_map[a].major == other->page_map[b].major)
285 {
286 count++;
287 a++;
288 b++;
289 }
290 else if (page_map[a].major < other->page_map[b].major)
291 {
292 if (Op::passthru_left)
293 count++;
294 a++;
295 }
296 else
297 {
298 if (Op::passthru_right)
299 count++;
300 b++;
301 }
302 }
303 if (Op::passthru_left)
304 count += na - a;
305 if (Op::passthru_right)
306 count += nb - b;
307
308 if (!resize (count))
309 return;
310
311 /* Process in-place backward. */
312 a = na;
313 b = nb;
314 for (; a && b; )
315 {
316 if (page_map[a - 1].major == other->page_map[b - 1].major)
317 {
318 a--;
319 b--;
320 Op::process (page_at (--count).v, page_at (a).v, other->page_at (b).v);
321 }
322 else if (page_map[a - 1].major > other->page_map[b - 1].major)
323 {
324 a--;
325 if (Op::passthru_left)
326 page_at (--count).v = page_at (a).v;
327 }
328 else
329 {
330 b--;
331 if (Op::passthru_right)
332 page_at (--count).v = other->page_at (b).v;
333 }
334 }
335 if (Op::passthru_left)
336 while (a)
337 page_at (--count).v = page_at (--a).v;
338 if (Op::passthru_right)
339 while (b)
340 page_at (--count).v = other->page_at (--b).v;
341 assert (!count);
342 }
343
344 inline void union_ (const hb_set_t *other)
345 {
346 process<HbOpOr> (other);
347 }
348 inline void intersect (const hb_set_t *other)
349 {
350 process<HbOpAnd> (other);
351 }
352 inline void subtract (const hb_set_t *other)
353 {
354 process<HbOpMinus> (other);
355 }
356 inline void symmetric_difference (const hb_set_t *other)
357 {
358 process<HbOpXor> (other);
359 }
360 inline bool next (hb_codepoint_t *codepoint) const
361 {
362 if (unlikely (*codepoint == INVALID)) {
363 *codepoint = get_min ();
364 return *codepoint != INVALID;
365 }
366
367 page_map_t map = {get_major (*codepoint), 0};
368 unsigned int i;
369 page_map.bfind (&map, &i);
370 if (i < page_map.len)
371 {
372 if (pages[page_map[i].index].next (codepoint))
373 {
374 *codepoint += page_map[i].major * page_t::PAGE_BITS;
375 return true;
376 }
377 i++;
378 }
379 for (; i < page_map.len; i++)
380 {
381 hb_codepoint_t m = pages[page_map[i].index].get_min ();
382 if (m != INVALID)
383 {
384 *codepoint = page_map[i].major * page_t::PAGE_BITS + m;
385 return true;
386 }
387 }
388 *codepoint = INVALID;
389 return false;
390 }
391 inline bool next_range (hb_codepoint_t *first, hb_codepoint_t *last) const
392 {
393 hb_codepoint_t i;
394
395 i = *last;
396 if (!next (&i))
397 {
398 *last = *first = INVALID;
399 return false;
400 }
401
402 *last = *first = i;
403 while (next (&i) && i == *last + 1)
404 (*last)++;
405
406 return true;
407 }
408
409 inline unsigned int get_population (void) const
410 {
411 unsigned int pop = 0;
412 unsigned int count = pages.len;
413 for (unsigned int i = 0; i < count; i++)
414 pop += pages[i].get_population ();
415 return pop;
416 }
417 inline hb_codepoint_t get_min (void) const
418 {
419 unsigned int count = pages.len;
420 for (unsigned int i = 0; i < count; i++)
421 if (!page_at (i).is_empty ())
422 return page_map[i].major * page_t::PAGE_BITS + page_at (i).get_min ();
423 return INVALID;
424 }
425 inline hb_codepoint_t get_max (void) const
426 {
427 unsigned int count = pages.len;
428 for (int i = count - 1; i >= 0; i++)
429 if (!page_at (i).is_empty ())
430 return page_map[i].major * page_t::PAGE_BITS + page_at (i).get_max ();
431 return INVALID;
432 }
433
434 static const hb_codepoint_t INVALID = HB_SET_VALUE_INVALID;
435
436 page_t *page_for_insert (hb_codepoint_t g)
437 {
438 page_map_t map = {get_major (g), pages.len};
439 unsigned int i;
440 if (!page_map.bfind (&map, &i))
441 {
442 if (!resize (pages.len + 1))
443 return nullptr;
444
445 pages[map.index].init ();
446 memmove (&page_map[i + 1], &page_map[i], (page_map.len - 1 - i) * sizeof (page_map[0]));
447 page_map[i] = map;
448 }
449 return &pages[page_map[i].index];
450 }
451 page_t *page_for (hb_codepoint_t g)
452 {
453 page_map_t key = {get_major (g)};
454 const page_map_t *found = page_map.bsearch (&key);
455 if (found)
456 return &pages[found->index];
457 return nullptr;
458 }
459 const page_t *page_for (hb_codepoint_t g) const
460 {
461 page_map_t key = {get_major (g)};
462 const page_map_t *found = page_map.bsearch (&key);
463 if (found)
464 return &pages[found->index];
465 return nullptr;
466 }
467 page_t &page_at (unsigned int i) { return pages[page_map[i].index]; }
468 const page_t &page_at (unsigned int i) const { return pages[page_map[i].index]; }
469 unsigned int get_major (hb_codepoint_t g) const { return g / page_t::PAGE_BITS; }
470 };
471
472
473 #endif /* HB_SET_PRIVATE_HH */