1/*
2 * Copyright © 2022 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): Garret Rieger
25 */
26
27#ifndef GRAPH_MARKBASEPOS_GRAPH_HH
28#define GRAPH_MARKBASEPOS_GRAPH_HH
29
30#include "split-helpers.hh"
31#include "coverage-graph.hh"
32#include "../OT/Layout/GPOS/MarkBasePos.hh"
33#include "../OT/Layout/GPOS/PosLookupSubTable.hh"
34
35namespace graph {
36
37struct AnchorMatrix : public OT::Layout::GPOS_impl::AnchorMatrix
38{
39 bool sanitize (graph_t::vertex_t& vertex, unsigned class_count) const
40 {
41 int64_t vertex_len = vertex.obj.tail - vertex.obj.head;
42 if (vertex_len < AnchorMatrix::min_size) return false;
43
44 return vertex_len >= AnchorMatrix::min_size +
45 OT::Offset16::static_size * class_count * this->rows;
46 }
47
48 bool shrink (gsubgpos_graph_context_t& c,
49 unsigned this_index,
50 unsigned old_class_count,
51 unsigned new_class_count)
52 {
53 if (new_class_count >= old_class_count) return false;
54 auto& o = c.graph.vertices_[this_index].obj;
55 unsigned base_count = rows;
56 o.tail = o.head +
57 AnchorMatrix::min_size +
58 OT::Offset16::static_size * base_count * new_class_count;
59
60 // Reposition links into the new indexing scheme.
61 for (auto& link : o.real_links.writer ())
62 {
63 unsigned index = (link.position - 2) / 2;
64 unsigned base = index / old_class_count;
65 unsigned klass = index % old_class_count;
66 if (klass >= new_class_count)
67 // should have already been removed
68 return false;
69
70 unsigned new_index = base * new_class_count + klass;
71
72 link.position = (char*) &(this->matrixZ[new_index]) - (char*) this;
73 }
74
75 return true;
76 }
77
78 unsigned clone (gsubgpos_graph_context_t& c,
79 unsigned this_index,
80 unsigned start,
81 unsigned end,
82 unsigned class_count)
83 {
84 unsigned base_count = rows;
85 unsigned new_class_count = end - start;
86 unsigned size = AnchorMatrix::min_size +
87 OT::Offset16::static_size * new_class_count * rows;
88 unsigned prime_id = c.create_node (size);
89 if (prime_id == (unsigned) -1) return -1;
90 AnchorMatrix* prime = (AnchorMatrix*) c.graph.object (prime_id).head;
91 prime->rows = base_count;
92
93 auto& o = c.graph.vertices_[this_index].obj;
94 int num_links = o.real_links.length;
95 for (int i = 0; i < num_links; i++)
96 {
97 const auto& link = o.real_links[i];
98 unsigned old_index = (link.position - 2) / OT::Offset16::static_size;
99 unsigned klass = old_index % class_count;
100 if (klass < start || klass >= end) continue;
101
102 unsigned base = old_index / class_count;
103 unsigned new_klass = klass - start;
104 unsigned new_index = base * new_class_count + new_klass;
105
106
107 unsigned child_idx = link.objidx;
108 c.graph.add_link (&(prime->matrixZ[new_index]),
109 prime_id,
110 child_idx);
111
112 auto& child = c.graph.vertices_[child_idx];
113 child.remove_parent (this_index);
114
115 o.real_links.remove_unordered (i);
116 num_links--;
117 i--;
118 }
119
120 return prime_id;
121 }
122};
123
124struct MarkArray : public OT::Layout::GPOS_impl::MarkArray
125{
126 bool sanitize (graph_t::vertex_t& vertex) const
127 {
128 int64_t vertex_len = vertex.obj.tail - vertex.obj.head;
129 unsigned min_size = MarkArray::min_size;
130 if (vertex_len < min_size) return false;
131
132 return vertex_len >= get_size ();
133 }
134
135 bool shrink (gsubgpos_graph_context_t& c,
136 const hb_hashmap_t<unsigned, unsigned>& mark_array_links,
137 unsigned this_index,
138 unsigned new_class_count)
139 {
140 auto& o = c.graph.vertices_[this_index].obj;
141 for (const auto& link : o.real_links)
142 c.graph.vertices_[link.objidx].remove_parent (this_index);
143 o.real_links.reset ();
144
145 unsigned new_index = 0;
146 for (const auto& record : this->iter ())
147 {
148 unsigned klass = record.klass;
149 if (klass >= new_class_count) continue;
150
151 (*this)[new_index].klass = klass;
152 unsigned position = (char*) &record.markAnchor - (char*) this;
153 unsigned* objidx;
154 if (!mark_array_links.has (position, &objidx))
155 {
156 new_index++;
157 continue;
158 }
159
160 c.graph.add_link (&(*this)[new_index].markAnchor, this_index, *objidx);
161 new_index++;
162 }
163
164 this->len = new_index;
165 o.tail = o.head + MarkArray::min_size +
166 OT::Layout::GPOS_impl::MarkRecord::static_size * new_index;
167 return true;
168 }
169
170 unsigned clone (gsubgpos_graph_context_t& c,
171 unsigned this_index,
172 const hb_hashmap_t<unsigned, unsigned>& pos_to_index,
173 hb_set_t& marks,
174 unsigned start_class)
175 {
176 unsigned size = MarkArray::min_size +
177 OT::Layout::GPOS_impl::MarkRecord::static_size *
178 marks.get_population ();
179 unsigned prime_id = c.create_node (size);
180 if (prime_id == (unsigned) -1) return -1;
181 MarkArray* prime = (MarkArray*) c.graph.object (prime_id).head;
182 prime->len = marks.get_population ();
183
184
185 unsigned i = 0;
186 for (hb_codepoint_t mark : marks)
187 {
188 (*prime)[i].klass = (*this)[mark].klass - start_class;
189 unsigned offset_pos = (char*) &((*this)[mark].markAnchor) - (char*) this;
190 unsigned* anchor_index;
191 if (pos_to_index.has (offset_pos, &anchor_index))
192 c.graph.move_child (this_index,
193 &((*this)[mark].markAnchor),
194 prime_id,
195 &((*prime)[i].markAnchor));
196
197 i++;
198 }
199
200 return prime_id;
201 }
202};
203
204struct MarkBasePosFormat1 : public OT::Layout::GPOS_impl::MarkBasePosFormat1_2<SmallTypes>
205{
206 bool sanitize (graph_t::vertex_t& vertex) const
207 {
208 int64_t vertex_len = vertex.obj.tail - vertex.obj.head;
209 return vertex_len >= MarkBasePosFormat1::static_size;
210 }
211
212 hb_vector_t<unsigned> split_subtables (gsubgpos_graph_context_t& c,
213 unsigned parent_index,
214 unsigned this_index)
215 {
216 hb_set_t visited;
217
218 const unsigned base_coverage_id = c.graph.index_for_offset (this_index, &baseCoverage);
219 const unsigned base_size =
220 OT::Layout::GPOS_impl::PairPosFormat1_3<SmallTypes>::min_size +
221 MarkArray::min_size +
222 AnchorMatrix::min_size +
223 c.graph.vertices_[base_coverage_id].table_size ();
224
225 hb_vector_t<class_info_t> class_to_info = get_class_info (c, this_index);
226
227 unsigned class_count = classCount;
228 auto base_array = c.graph.as_table<AnchorMatrix> (this_index,
229 &baseArray,
230 class_count);
231 if (!base_array) return hb_vector_t<unsigned> ();
232 unsigned base_count = base_array.table->rows;
233
234 unsigned partial_coverage_size = 4;
235 unsigned accumulated = base_size;
236 hb_vector_t<unsigned> split_points;
237
238 for (unsigned klass = 0; klass < class_count; klass++)
239 {
240 class_info_t& info = class_to_info[klass];
241 partial_coverage_size += OT::HBUINT16::static_size * info.marks.get_population ();
242 unsigned accumulated_delta =
243 OT::Layout::GPOS_impl::MarkRecord::static_size * info.marks.get_population () +
244 OT::Offset16::static_size * base_count;
245
246 for (unsigned objidx : info.child_indices)
247 accumulated_delta += c.graph.find_subgraph_size (objidx, visited);
248
249 accumulated += accumulated_delta;
250 unsigned total = accumulated + partial_coverage_size;
251
252 if (total >= (1 << 16))
253 {
254 split_points.push (klass);
255 accumulated = base_size + accumulated_delta;
256 partial_coverage_size = 4 + OT::HBUINT16::static_size * info.marks.get_population ();
257 visited.clear (); // node sharing isn't allowed between splits.
258 }
259 }
260
261
262 const unsigned mark_array_id = c.graph.index_for_offset (this_index, &markArray);
263 split_context_t split_context {
264 c,
265 this,
266 c.graph.duplicate_if_shared (parent_index, this_index),
267 std::move (class_to_info),
268 c.graph.vertices_[mark_array_id].position_to_index_map (),
269 };
270
271 return actuate_subtable_split<split_context_t> (split_context, split_points);
272 }
273
274 private:
275
276 struct class_info_t {
277 hb_set_t marks;
278 hb_vector_t<unsigned> child_indices;
279 };
280
281 struct split_context_t {
282 gsubgpos_graph_context_t& c;
283 MarkBasePosFormat1* thiz;
284 unsigned this_index;
285 hb_vector_t<class_info_t> class_to_info;
286 hb_hashmap_t<unsigned, unsigned> mark_array_links;
287
288 hb_set_t marks_for (unsigned start, unsigned end)
289 {
290 hb_set_t marks;
291 for (unsigned klass = start; klass < end; klass++)
292 {
293 + class_to_info[klass].marks.iter ()
294 | hb_sink (marks)
295 ;
296 }
297 return marks;
298 }
299
300 unsigned original_count ()
301 {
302 return thiz->classCount;
303 }
304
305 unsigned clone_range (unsigned start, unsigned end)
306 {
307 return thiz->clone_range (*this, this->this_index, start, end);
308 }
309
310 bool shrink (unsigned count)
311 {
312 return thiz->shrink (*this, this->this_index, count);
313 }
314 };
315
316 hb_vector_t<class_info_t> get_class_info (gsubgpos_graph_context_t& c,
317 unsigned this_index)
318 {
319 hb_vector_t<class_info_t> class_to_info;
320
321 unsigned class_count= classCount;
322 if (!class_to_info.resize (class_count))
323 return hb_vector_t<class_info_t>();
324
325 auto mark_array = c.graph.as_table<MarkArray> (this_index, &markArray);
326 if (!mark_array) return hb_vector_t<class_info_t> ();
327 unsigned mark_count = mark_array.table->len;
328 for (unsigned mark = 0; mark < mark_count; mark++)
329 {
330 unsigned klass = (*mark_array.table)[mark].get_class ();
331 if (klass >= class_count) continue;
332 class_to_info[klass].marks.add (mark);
333 }
334
335 for (const auto& link : mark_array.vertex->obj.real_links)
336 {
337 unsigned mark = (link.position - 2) /
338 OT::Layout::GPOS_impl::MarkRecord::static_size;
339 unsigned klass = (*mark_array.table)[mark].get_class ();
340 if (klass >= class_count) continue;
341 class_to_info[klass].child_indices.push (link.objidx);
342 }
343
344 unsigned base_array_id =
345 c.graph.index_for_offset (this_index, &baseArray);
346 auto& base_array_v = c.graph.vertices_[base_array_id];
347
348 for (const auto& link : base_array_v.obj.real_links)
349 {
350 unsigned index = (link.position - 2) / OT::Offset16::static_size;
351 unsigned klass = index % class_count;
352 class_to_info[klass].child_indices.push (link.objidx);
353 }
354
355 return class_to_info;
356 }
357
358 bool shrink (split_context_t& sc,
359 unsigned this_index,
360 unsigned count)
361 {
362 DEBUG_MSG (SUBSET_REPACK, nullptr,
363 " Shrinking MarkBasePosFormat1 (%u) to [0, %u).",
364 this_index,
365 count);
366
367 unsigned old_count = classCount;
368 if (count >= old_count)
369 return true;
370
371 classCount = count;
372
373 auto mark_coverage = sc.c.graph.as_mutable_table<Coverage> (this_index,
374 &markCoverage);
375 if (!mark_coverage) return false;
376 hb_set_t marks = sc.marks_for (0, count);
377 auto new_coverage =
378 + hb_enumerate (mark_coverage.table->iter ())
379 | hb_filter (marks, hb_first)
380 | hb_map_retains_sorting (hb_second)
381 ;
382 if (!Coverage::make_coverage (sc.c, + new_coverage,
383 mark_coverage.index,
384 4 + 2 * marks.get_population ()))
385 return false;
386
387
388 auto base_array = sc.c.graph.as_mutable_table<AnchorMatrix> (this_index,
389 &baseArray,
390 old_count);
391 if (!base_array || !base_array.table->shrink (sc.c,
392 base_array.index,
393 old_count,
394 count))
395 return false;
396
397 auto mark_array = sc.c.graph.as_mutable_table<MarkArray> (this_index,
398 &markArray);
399 if (!mark_array || !mark_array.table->shrink (sc.c,
400 sc.mark_array_links,
401 mark_array.index,
402 count))
403 return false;
404
405 return true;
406 }
407
408 // Create a new MarkBasePos that has all of the data for classes from [start, end).
409 unsigned clone_range (split_context_t& sc,
410 unsigned this_index,
411 unsigned start, unsigned end) const
412 {
413 DEBUG_MSG (SUBSET_REPACK, nullptr,
414 " Cloning MarkBasePosFormat1 (%u) range [%u, %u).", this_index, start, end);
415
416 graph_t& graph = sc.c.graph;
417 unsigned prime_size = OT::Layout::GPOS_impl::MarkBasePosFormat1_2<SmallTypes>::static_size;
418
419 unsigned prime_id = sc.c.create_node (prime_size);
420 if (prime_id == (unsigned) -1) return -1;
421
422 MarkBasePosFormat1* prime = (MarkBasePosFormat1*) graph.object (prime_id).head;
423 prime->format = this->format;
424 unsigned new_class_count = end - start;
425 prime->classCount = new_class_count;
426
427 unsigned base_coverage_id =
428 graph.index_for_offset (sc.this_index, &baseCoverage);
429 graph.add_link (&(prime->baseCoverage), prime_id, base_coverage_id);
430 graph.duplicate (prime_id, base_coverage_id);
431
432 auto mark_coverage = sc.c.graph.as_table<Coverage> (this_index,
433 &markCoverage);
434 if (!mark_coverage) return false;
435 hb_set_t marks = sc.marks_for (start, end);
436 auto new_coverage =
437 + hb_enumerate (mark_coverage.table->iter ())
438 | hb_filter (marks, hb_first)
439 | hb_map_retains_sorting (hb_second)
440 ;
441 if (!Coverage::add_coverage (sc.c,
442 prime_id,
443 2,
444 + new_coverage,
445 marks.get_population () * 2 + 4))
446 return -1;
447
448 auto mark_array =
449 graph.as_table <MarkArray> (sc.this_index, &markArray);
450 if (!mark_array) return -1;
451 unsigned new_mark_array =
452 mark_array.table->clone (sc.c,
453 mark_array.index,
454 sc.mark_array_links,
455 marks,
456 start);
457 graph.add_link (&(prime->markArray), prime_id, new_mark_array);
458
459 unsigned class_count = classCount;
460 auto base_array =
461 graph.as_table<AnchorMatrix> (sc.this_index, &baseArray, class_count);
462 if (!base_array) return -1;
463 unsigned new_base_array =
464 base_array.table->clone (sc.c,
465 base_array.index,
466 start, end, this->classCount);
467 graph.add_link (&(prime->baseArray), prime_id, new_base_array);
468
469 return prime_id;
470 }
471};
472
473
474struct MarkBasePos : public OT::Layout::GPOS_impl::MarkBasePos
475{
476 hb_vector_t<unsigned> split_subtables (gsubgpos_graph_context_t& c,
477 unsigned parent_index,
478 unsigned this_index)
479 {
480 switch (u.format) {
481 case 1:
482 return ((MarkBasePosFormat1*)(&u.format1))->split_subtables (c, parent_index, this_index);
483#ifndef HB_NO_BEYOND_64K
484 case 2: HB_FALLTHROUGH;
485 // Don't split 24bit PairPos's.
486#endif
487 default:
488 return hb_vector_t<unsigned> ();
489 }
490 }
491
492 bool sanitize (graph_t::vertex_t& vertex) const
493 {
494 int64_t vertex_len = vertex.obj.tail - vertex.obj.head;
495 if (vertex_len < u.format.get_size ()) return false;
496
497 switch (u.format) {
498 case 1:
499 return ((MarkBasePosFormat1*)(&u.format1))->sanitize (vertex);
500#ifndef HB_NO_BEYOND_64K
501 case 2: HB_FALLTHROUGH;
502#endif
503 default:
504 // We don't handle format 3 and 4 here.
505 return false;
506 }
507 }
508};
509
510
511}
512
513#endif // GRAPH_MARKBASEPOS_GRAPH_HH
514