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_HH
28#define HB_SET_HH
29
30#include "hb.hh"
31#include "hb-machinery.hh"
32
33
34/*
35 * hb_set_t
36 */
37
38/* TODO Keep a free-list so we can free pages that are completely zeroed. At that
39 * point maybe also use a sentinel value for "all-1" pages? */
40
41struct hb_set_t
42{
43 HB_DELETE_COPY_ASSIGN (hb_set_t);
44 hb_set_t () { init (); }
45 ~hb_set_t () { fini (); }
46
47 struct page_map_t
48 {
49 int cmp (const page_map_t &o) const { return (int) o.major - (int) major; }
50
51 uint32_t major;
52 uint32_t index;
53 };
54
55 struct page_t
56 {
57 void init0 () { v.clear (); }
58 void init1 () { v.clear (0xFF); }
59
60 unsigned int len () const
61 { return ARRAY_LENGTH_CONST (v); }
62
63 bool is_empty () const
64 {
65 for (unsigned int i = 0; i < len (); i++)
66 if (v[i])
67 return false;
68 return true;
69 }
70
71 void add (hb_codepoint_t g) { elt (g) |= mask (g); }
72 void del (hb_codepoint_t g) { elt (g) &= ~mask (g); }
73 bool get (hb_codepoint_t g) const { return elt (g) & mask (g); }
74
75 void add_range (hb_codepoint_t a, hb_codepoint_t b)
76 {
77 elt_t *la = &elt (a);
78 elt_t *lb = &elt (b);
79 if (la == lb)
80 *la |= (mask (b) << 1) - mask(a);
81 else
82 {
83 *la |= ~(mask (a) - 1);
84 la++;
85
86 memset (la, 0xff, (char *) lb - (char *) la);
87
88 *lb |= ((mask (b) << 1) - 1);
89 }
90 }
91
92 void del_range (hb_codepoint_t a, hb_codepoint_t b)
93 {
94 elt_t *la = &elt (a);
95 elt_t *lb = &elt (b);
96 if (la == lb)
97 *la &= ~((mask (b) << 1) - mask(a));
98 else
99 {
100 *la &= mask (a) - 1;
101 la++;
102
103 memset (la, 0, (char *) lb - (char *) la);
104
105 *lb &= ~((mask (b) << 1) - 1);
106 }
107 }
108
109 bool is_equal (const page_t *other) const
110 {
111 return 0 == hb_memcmp (&v, &other->v, sizeof (v));
112 }
113
114 unsigned int get_population () const
115 {
116 unsigned int pop = 0;
117 for (unsigned int i = 0; i < len (); i++)
118 pop += hb_popcount (v[i]);
119 return pop;
120 }
121
122 bool next (hb_codepoint_t *codepoint) const
123 {
124 unsigned int m = (*codepoint + 1) & MASK;
125 if (!m)
126 {
127 *codepoint = INVALID;
128 return false;
129 }
130 unsigned int i = m / ELT_BITS;
131 unsigned int j = m & ELT_MASK;
132
133 const elt_t vv = v[i] & ~((elt_t (1) << j) - 1);
134 for (const elt_t *p = &vv; i < len (); p = &v[++i])
135 if (*p)
136 {
137 *codepoint = i * ELT_BITS + elt_get_min (*p);
138 return true;
139 }
140
141 *codepoint = INVALID;
142 return false;
143 }
144 bool previous (hb_codepoint_t *codepoint) const
145 {
146 unsigned int m = (*codepoint - 1) & MASK;
147 if (m == MASK)
148 {
149 *codepoint = INVALID;
150 return false;
151 }
152 unsigned int i = m / ELT_BITS;
153 unsigned int j = m & ELT_MASK;
154
155 /* Fancy mask to avoid shifting by elt_t bitsize, which is undefined. */
156 const elt_t mask = j < 8 * sizeof (elt_t) - 1 ?
157 ((elt_t (1) << (j + 1)) - 1) :
158 (elt_t) -1;
159 const elt_t vv = v[i] & mask;
160 const elt_t *p = &vv;
161 while (true)
162 {
163 if (*p)
164 {
165 *codepoint = i * ELT_BITS + elt_get_max (*p);
166 return true;
167 }
168 if ((int) i <= 0) break;
169 p = &v[--i];
170 }
171
172 *codepoint = INVALID;
173 return false;
174 }
175 hb_codepoint_t get_min () const
176 {
177 for (unsigned int i = 0; i < len (); i++)
178 if (v[i])
179 return i * ELT_BITS + elt_get_min (v[i]);
180 return INVALID;
181 }
182 hb_codepoint_t get_max () const
183 {
184 for (int i = len () - 1; i >= 0; i--)
185 if (v[i])
186 return i * ELT_BITS + elt_get_max (v[i]);
187 return 0;
188 }
189
190 typedef unsigned long long elt_t;
191 static constexpr unsigned PAGE_BITS = 512;
192 static_assert ((PAGE_BITS & ((PAGE_BITS) - 1)) == 0, "");
193
194 static unsigned int elt_get_min (const elt_t &elt) { return hb_ctz (elt); }
195 static unsigned int elt_get_max (const elt_t &elt) { return hb_bit_storage (elt) - 1; }
196
197 typedef hb_vector_size_t<elt_t, PAGE_BITS / 8> vector_t;
198
199 static constexpr unsigned ELT_BITS = sizeof (elt_t) * 8;
200 static constexpr unsigned ELT_MASK = ELT_BITS - 1;
201 static constexpr unsigned BITS = sizeof (vector_t) * 8;
202 static constexpr unsigned MASK = BITS - 1;
203 static_assert ((unsigned) PAGE_BITS == (unsigned) BITS, "");
204
205 elt_t &elt (hb_codepoint_t g) { return v[(g & MASK) / ELT_BITS]; }
206 elt_t const &elt (hb_codepoint_t g) const { return v[(g & MASK) / ELT_BITS]; }
207 elt_t mask (hb_codepoint_t g) const { return elt_t (1) << (g & ELT_MASK); }
208
209 vector_t v;
210 };
211 static_assert (page_t::PAGE_BITS == sizeof (page_t) * 8, "");
212
213 hb_object_header_t header;
214 bool successful; /* Allocations successful */
215 mutable unsigned int population;
216 hb_sorted_vector_t<page_map_t> page_map;
217 hb_vector_t<page_t> pages;
218
219 void init_shallow ()
220 {
221 successful = true;
222 population = 0;
223 page_map.init ();
224 pages.init ();
225 }
226 void init ()
227 {
228 hb_object_init (this);
229 init_shallow ();
230 }
231 void fini_shallow ()
232 {
233 population = 0;
234 page_map.fini ();
235 pages.fini ();
236 }
237 void fini ()
238 {
239 hb_object_fini (this);
240 fini_shallow ();
241 }
242
243 bool in_error () const { return !successful; }
244
245 bool resize (unsigned int count)
246 {
247 if (unlikely (!successful)) return false;
248 if (!pages.resize (count) || !page_map.resize (count))
249 {
250 pages.resize (page_map.length);
251 successful = false;
252 return false;
253 }
254 return true;
255 }
256
257 void reset ()
258 {
259 if (unlikely (hb_object_is_immutable (this)))
260 return;
261 clear ();
262 successful = true;
263 }
264
265 void clear ()
266 {
267 if (unlikely (hb_object_is_immutable (this)))
268 return;
269 population = 0;
270 page_map.resize (0);
271 pages.resize (0);
272 }
273 bool is_empty () const
274 {
275 unsigned int count = pages.length;
276 for (unsigned int i = 0; i < count; i++)
277 if (!pages[i].is_empty ())
278 return false;
279 return true;
280 }
281
282 void dirty () { population = UINT_MAX; }
283
284 void add (hb_codepoint_t g)
285 {
286 if (unlikely (!successful)) return;
287 if (unlikely (g == INVALID)) return;
288 dirty ();
289 page_t *page = page_for_insert (g); if (unlikely (!page)) return;
290 page->add (g);
291 }
292 bool add_range (hb_codepoint_t a, hb_codepoint_t b)
293 {
294 if (unlikely (!successful)) return true; /* https://github.com/harfbuzz/harfbuzz/issues/657 */
295 if (unlikely (a > b || a == INVALID || b == INVALID)) return false;
296 dirty ();
297 unsigned int ma = get_major (a);
298 unsigned int mb = get_major (b);
299 if (ma == mb)
300 {
301 page_t *page = page_for_insert (a); if (unlikely (!page)) return false;
302 page->add_range (a, b);
303 }
304 else
305 {
306 page_t *page = page_for_insert (a); if (unlikely (!page)) return false;
307 page->add_range (a, major_start (ma + 1) - 1);
308
309 for (unsigned int m = ma + 1; m < mb; m++)
310 {
311 page = page_for_insert (major_start (m)); if (unlikely (!page)) return false;
312 page->init1 ();
313 }
314
315 page = page_for_insert (b); if (unlikely (!page)) return false;
316 page->add_range (major_start (mb), b);
317 }
318 return true;
319 }
320
321 template <typename T>
322 void add_array (const T *array, unsigned int count, unsigned int stride=sizeof(T))
323 {
324 if (unlikely (!successful)) return;
325 if (!count) return;
326 dirty ();
327 hb_codepoint_t g = *array;
328 while (count)
329 {
330 unsigned int m = get_major (g);
331 page_t *page = page_for_insert (g); if (unlikely (!page)) return;
332 unsigned int start = major_start (m);
333 unsigned int end = major_start (m + 1);
334 do
335 {
336 page->add (g);
337
338 array = &StructAtOffsetUnaligned<T> (array, stride);
339 count--;
340 }
341 while (count && (g = *array, start <= g && g < end));
342 }
343 }
344
345 /* Might return false if array looks unsorted.
346 * Used for faster rejection of corrupt data. */
347 template <typename T>
348 bool add_sorted_array (const T *array, unsigned int count, unsigned int stride=sizeof(T))
349 {
350 if (unlikely (!successful)) return true; /* https://github.com/harfbuzz/harfbuzz/issues/657 */
351 if (!count) return true;
352 dirty ();
353 hb_codepoint_t g = *array;
354 hb_codepoint_t last_g = g;
355 while (count)
356 {
357 unsigned int m = get_major (g);
358 page_t *page = page_for_insert (g); if (unlikely (!page)) return false;
359 unsigned int end = major_start (m + 1);
360 do
361 {
362 /* If we try harder we can change the following comparison to <=;
363 * Not sure if it's worth it. */
364 if (g < last_g) return false;
365 last_g = g;
366 page->add (g);
367
368 array = (const T *) ((const char *) array + stride);
369 count--;
370 }
371 while (count && (g = *array, g < end));
372 }
373 return true;
374 }
375
376 void del (hb_codepoint_t g)
377 {
378 /* TODO perform op even if !successful. */
379 if (unlikely (!successful)) return;
380 page_t *page = page_for (g);
381 if (!page)
382 return;
383 dirty ();
384 page->del (g);
385 }
386
387 private:
388 void del_pages (int ds, int de)
389 {
390 if (ds <= de)
391 {
392 unsigned int write_index = 0;
393 for (unsigned int i = 0; i < page_map.length; i++)
394 {
395 int m = (int) page_map[i].major;
396 if (m < ds || de < m)
397 page_map[write_index++] = page_map[i];
398 }
399 compact (write_index);
400 resize (write_index);
401 }
402 }
403
404 public:
405 void del_range (hb_codepoint_t a, hb_codepoint_t b)
406 {
407 /* TODO perform op even if !successful. */
408 if (unlikely (!successful)) return;
409 if (unlikely (a > b || a == INVALID || b == INVALID)) return;
410 dirty ();
411 unsigned int ma = get_major (a);
412 unsigned int mb = get_major (b);
413 /* Delete pages from ds through de if ds <= de. */
414 int ds = (a == major_start (ma))? (int) ma: (int) (ma + 1);
415 int de = (b + 1 == major_start (mb + 1))? (int) mb: ((int) mb - 1);
416 if (ds > de || (int) ma < ds)
417 {
418 page_t *page = page_for (a);
419 if (page)
420 {
421 if (ma == mb)
422 page->del_range (a, b);
423 else
424 page->del_range (a, major_start (ma + 1) - 1);
425 }
426 }
427 if (de < (int) mb && ma != mb)
428 {
429 page_t *page = page_for (b);
430 if (page)
431 page->del_range (major_start (mb), b);
432 }
433 del_pages (ds, de);
434 }
435
436 bool get (hb_codepoint_t g) const
437 {
438 const page_t *page = page_for (g);
439 if (!page)
440 return false;
441 return page->get (g);
442 }
443
444 /* Has interface. */
445 static constexpr bool SENTINEL = false;
446 typedef bool value_t;
447 value_t operator [] (hb_codepoint_t k) const { return get (k); }
448 bool has (hb_codepoint_t k) const { return (*this)[k] != SENTINEL; }
449 /* Predicate. */
450 bool operator () (hb_codepoint_t k) const { return has (k); }
451
452 /* Sink interface. */
453 hb_set_t& operator << (hb_codepoint_t v)
454 { add (v); return *this; }
455 hb_set_t& operator << (const hb_pair_t<hb_codepoint_t, hb_codepoint_t>& range)
456 { add_range (range.first, range.second); return *this; }
457
458 bool intersects (hb_codepoint_t first, hb_codepoint_t last) const
459 {
460 hb_codepoint_t c = first - 1;
461 return next (&c) && c <= last;
462 }
463 void set (const hb_set_t *other)
464 {
465 if (unlikely (!successful)) return;
466 unsigned int count = other->pages.length;
467 if (!resize (count))
468 return;
469 population = other->population;
470 memcpy ((void *) pages, (const void *) other->pages, count * pages.item_size);
471 memcpy ((void *) page_map, (const void *) other->page_map, count * page_map.item_size);
472 }
473
474 bool is_equal (const hb_set_t *other) const
475 {
476 if (get_population () != other->get_population ())
477 return false;
478
479 unsigned int na = pages.length;
480 unsigned int nb = other->pages.length;
481
482 unsigned int a = 0, b = 0;
483 for (; a < na && b < nb; )
484 {
485 if (page_at (a).is_empty ()) { a++; continue; }
486 if (other->page_at (b).is_empty ()) { b++; continue; }
487 if (page_map[a].major != other->page_map[b].major ||
488 !page_at (a).is_equal (&other->page_at (b)))
489 return false;
490 a++;
491 b++;
492 }
493 for (; a < na; a++)
494 if (!page_at (a).is_empty ()) { return false; }
495 for (; b < nb; b++)
496 if (!other->page_at (b).is_empty ()) { return false; }
497
498 return true;
499 }
500
501 bool is_subset (const hb_set_t *larger_set) const
502 {
503 if (get_population () > larger_set->get_population ())
504 return false;
505
506 /* TODO Optimize to use pages. */
507 hb_codepoint_t c = INVALID;
508 while (next (&c))
509 if (!larger_set->has (c))
510 return false;
511
512 return true;
513 }
514
515 void compact (unsigned int length)
516 {
517 hb_vector_t<uint32_t> old_index_to_page_map_index;
518 old_index_to_page_map_index.resize(pages.length);
519 for (uint32_t i = 0; i < old_index_to_page_map_index.length; i++)
520 old_index_to_page_map_index[i] = 0xFFFFFFFF;
521
522 for (uint32_t i = 0; i < length; i++)
523 old_index_to_page_map_index[page_map[i].index] = i;
524
525 compact_pages (old_index_to_page_map_index);
526 }
527
528 void compact_pages (const hb_vector_t<uint32_t>& old_index_to_page_map_index)
529 {
530 unsigned int write_index = 0;
531 for (unsigned int i = 0; i < pages.length; i++)
532 {
533 if (old_index_to_page_map_index[i] == 0xFFFFFFFF) continue;
534
535 if (write_index < i)
536 pages[write_index] = pages[i];
537
538 page_map[old_index_to_page_map_index[i]].index = write_index;
539 write_index++;
540 }
541 }
542
543 template <typename Op>
544 void process (const Op& op, const hb_set_t *other)
545 {
546 if (unlikely (!successful)) return;
547
548 dirty ();
549
550 unsigned int na = pages.length;
551 unsigned int nb = other->pages.length;
552 unsigned int next_page = na;
553
554 unsigned int count = 0, newCount = 0;
555 unsigned int a = 0, b = 0;
556 unsigned int write_index = 0;
557 for (; a < na && b < nb; )
558 {
559 if (page_map[a].major == other->page_map[b].major)
560 {
561 if (!Op::passthru_left)
562 {
563 // Move page_map entries that we're keeping from the left side set
564 // to the front of the page_map vector. This isn't necessary if
565 // passthru_left is set since no left side pages will be removed
566 // in that case.
567 if (write_index < a)
568 page_map[write_index] = page_map[a];
569 write_index++;
570 }
571
572 count++;
573 a++;
574 b++;
575 }
576 else if (page_map[a].major < other->page_map[b].major)
577 {
578 if (Op::passthru_left)
579 count++;
580 a++;
581 }
582 else
583 {
584 if (Op::passthru_right)
585 count++;
586 b++;
587 }
588 }
589 if (Op::passthru_left)
590 count += na - a;
591 if (Op::passthru_right)
592 count += nb - b;
593
594 if (!Op::passthru_left)
595 {
596 na = write_index;
597 next_page = write_index;
598 compact (write_index);
599 }
600
601 if (!resize (count))
602 return;
603
604 newCount = count;
605
606 /* Process in-place backward. */
607 a = na;
608 b = nb;
609 for (; a && b; )
610 {
611 if (page_map[a - 1].major == other->page_map[b - 1].major)
612 {
613 a--;
614 b--;
615 count--;
616 page_map[count] = page_map[a];
617 page_at (count).v = op (page_at (a).v, other->page_at (b).v);
618 }
619 else if (page_map[a - 1].major > other->page_map[b - 1].major)
620 {
621 a--;
622 if (Op::passthru_left)
623 {
624 count--;
625 page_map[count] = page_map[a];
626 }
627 }
628 else
629 {
630 b--;
631 if (Op::passthru_right)
632 {
633 count--;
634 page_map[count].major = other->page_map[b].major;
635 page_map[count].index = next_page++;
636 page_at (count).v = other->page_at (b).v;
637 }
638 }
639 }
640 if (Op::passthru_left)
641 while (a)
642 {
643 a--;
644 count--;
645 page_map[count] = page_map [a];
646 }
647 if (Op::passthru_right)
648 while (b)
649 {
650 b--;
651 count--;
652 page_map[count].major = other->page_map[b].major;
653 page_map[count].index = next_page++;
654 page_at (count).v = other->page_at (b).v;
655 }
656 assert (!count);
657 if (pages.length > newCount)
658 resize (newCount);
659 }
660
661 void union_ (const hb_set_t *other)
662 {
663 process (hb_bitwise_or, other);
664 }
665 void intersect (const hb_set_t *other)
666 {
667 process (hb_bitwise_and, other);
668 }
669 void subtract (const hb_set_t *other)
670 {
671 process (hb_bitwise_sub, other);
672 }
673 void symmetric_difference (const hb_set_t *other)
674 {
675 process (hb_bitwise_xor, other);
676 }
677 bool next (hb_codepoint_t *codepoint) const
678 {
679 if (unlikely (*codepoint == INVALID)) {
680 *codepoint = get_min ();
681 return *codepoint != INVALID;
682 }
683
684 page_map_t map = {get_major (*codepoint), 0};
685 unsigned int i;
686 page_map.bfind (map, &i, HB_BFIND_NOT_FOUND_STORE_CLOSEST);
687 if (i < page_map.length && page_map[i].major == map.major)
688 {
689 if (pages[page_map[i].index].next (codepoint))
690 {
691 *codepoint += page_map[i].major * page_t::PAGE_BITS;
692 return true;
693 }
694 i++;
695 }
696 for (; i < page_map.length; i++)
697 {
698 hb_codepoint_t m = pages[page_map[i].index].get_min ();
699 if (m != INVALID)
700 {
701 *codepoint = page_map[i].major * page_t::PAGE_BITS + m;
702 return true;
703 }
704 }
705 *codepoint = INVALID;
706 return false;
707 }
708 bool previous (hb_codepoint_t *codepoint) const
709 {
710 if (unlikely (*codepoint == INVALID)) {
711 *codepoint = get_max ();
712 return *codepoint != INVALID;
713 }
714
715 page_map_t map = {get_major (*codepoint), 0};
716 unsigned int i;
717 page_map.bfind (map, &i, HB_BFIND_NOT_FOUND_STORE_CLOSEST);
718 if (i < page_map.length && page_map[i].major == map.major)
719 {
720 if (pages[page_map[i].index].previous (codepoint))
721 {
722 *codepoint += page_map[i].major * page_t::PAGE_BITS;
723 return true;
724 }
725 }
726 i--;
727 for (; (int) i >= 0; i--)
728 {
729 hb_codepoint_t m = pages[page_map[i].index].get_max ();
730 if (m != INVALID)
731 {
732 *codepoint = page_map[i].major * page_t::PAGE_BITS + m;
733 return true;
734 }
735 }
736 *codepoint = INVALID;
737 return false;
738 }
739 bool next_range (hb_codepoint_t *first, hb_codepoint_t *last) const
740 {
741 hb_codepoint_t i;
742
743 i = *last;
744 if (!next (&i))
745 {
746 *last = *first = INVALID;
747 return false;
748 }
749
750 /* TODO Speed up. */
751 *last = *first = i;
752 while (next (&i) && i == *last + 1)
753 (*last)++;
754
755 return true;
756 }
757 bool previous_range (hb_codepoint_t *first, hb_codepoint_t *last) const
758 {
759 hb_codepoint_t i;
760
761 i = *first;
762 if (!previous (&i))
763 {
764 *last = *first = INVALID;
765 return false;
766 }
767
768 /* TODO Speed up. */
769 *last = *first = i;
770 while (previous (&i) && i == *first - 1)
771 (*first)--;
772
773 return true;
774 }
775
776 unsigned int get_population () const
777 {
778 if (population != UINT_MAX)
779 return population;
780
781 unsigned int pop = 0;
782 unsigned int count = pages.length;
783 for (unsigned int i = 0; i < count; i++)
784 pop += pages[i].get_population ();
785
786 population = pop;
787 return pop;
788 }
789 hb_codepoint_t get_min () const
790 {
791 unsigned int count = pages.length;
792 for (unsigned int i = 0; i < count; i++)
793 if (!page_at (i).is_empty ())
794 return page_map[i].major * page_t::PAGE_BITS + page_at (i).get_min ();
795 return INVALID;
796 }
797 hb_codepoint_t get_max () const
798 {
799 unsigned int count = pages.length;
800 for (int i = count - 1; i >= 0; i++)
801 if (!page_at (i).is_empty ())
802 return page_map[(unsigned) i].major * page_t::PAGE_BITS + page_at (i).get_max ();
803 return INVALID;
804 }
805
806 static constexpr hb_codepoint_t INVALID = HB_SET_VALUE_INVALID;
807
808 /*
809 * Iterator implementation.
810 */
811 struct iter_t : hb_iter_with_fallback_t<iter_t, hb_codepoint_t>
812 {
813 static constexpr bool is_sorted_iterator = true;
814 iter_t (const hb_set_t &s_ = Null (hb_set_t),
815 bool init = true) : s (&s_), v (INVALID), l(0)
816 {
817 if (init)
818 {
819 l = s->get_population () + 1;
820 __next__ ();
821 }
822 }
823
824 typedef hb_codepoint_t __item_t__;
825 hb_codepoint_t __item__ () const { return v; }
826 bool __more__ () const { return v != INVALID; }
827 void __next__ () { s->next (&v); if (l) l--; }
828 void __prev__ () { s->previous (&v); }
829 unsigned __len__ () const { return l; }
830 iter_t end () const { return iter_t (*s, false); }
831 bool operator != (const iter_t& o) const
832 { return s != o.s || v != o.v; }
833
834 protected:
835 const hb_set_t *s;
836 hb_codepoint_t v;
837 unsigned l;
838 };
839 iter_t iter () const { return iter_t (*this); }
840 operator iter_t () const { return iter (); }
841
842 protected:
843
844 page_t *page_for_insert (hb_codepoint_t g)
845 {
846 page_map_t map = {get_major (g), pages.length};
847 unsigned int i;
848 if (!page_map.bfind (map, &i, HB_BFIND_NOT_FOUND_STORE_CLOSEST))
849 {
850 if (!resize (pages.length + 1))
851 return nullptr;
852
853 pages[map.index].init0 ();
854 memmove (page_map + i + 1,
855 page_map + i,
856 (page_map.length - 1 - i) * page_map.item_size);
857 page_map[i] = map;
858 }
859 return &pages[page_map[i].index];
860 }
861 page_t *page_for (hb_codepoint_t g)
862 {
863 page_map_t key = {get_major (g)};
864 const page_map_t *found = page_map.bsearch (key);
865 if (found)
866 return &pages[found->index];
867 return nullptr;
868 }
869 const page_t *page_for (hb_codepoint_t g) const
870 {
871 page_map_t key = {get_major (g)};
872 const page_map_t *found = page_map.bsearch (key);
873 if (found)
874 return &pages[found->index];
875 return nullptr;
876 }
877 page_t &page_at (unsigned int i) { return pages[page_map[i].index]; }
878 const page_t &page_at (unsigned int i) const { return pages[page_map[i].index]; }
879 unsigned int get_major (hb_codepoint_t g) const { return g / page_t::PAGE_BITS; }
880 hb_codepoint_t major_start (unsigned int major) const { return major * page_t::PAGE_BITS; }
881};
882
883
884#endif /* HB_SET_HH */
885