Use nullptr in a few places.
[pulseview.git] / pv / data / logicsegment.cpp
1 /*
2  * This file is part of the PulseView project.
3  *
4  * Copyright (C) 2012 Joel Holdsworth <joel@airwebreathe.org.uk>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, see <http://www.gnu.org/licenses/>.
18  */
19
20 #include <extdef.h>
21
22 #include <assert.h>
23 #include <string.h>
24 #include <stdlib.h>
25 #include <cmath>
26
27 #include "logic.hpp"
28 #include "logicsegment.hpp"
29
30 #include <libsigrokcxx/libsigrokcxx.hpp>
31
32 using std::lock_guard;
33 using std::recursive_mutex;
34 using std::max;
35 using std::min;
36 using std::pair;
37 using std::shared_ptr;
38
39 using sigrok::Logic;
40
41 namespace pv {
42 namespace data {
43
44 const int LogicSegment::MipMapScalePower = 4;
45 const int LogicSegment::MipMapScaleFactor = 1 << MipMapScalePower;
46 const float LogicSegment::LogMipMapScaleFactor = logf(MipMapScaleFactor);
47 const uint64_t LogicSegment::MipMapDataUnit = 64*1024;  // bytes
48
49 LogicSegment::LogicSegment(pv::data::Logic& owner, shared_ptr<sigrok::Logic> data,
50         uint64_t samplerate) :
51         Segment(samplerate, data->unit_size()),
52         owner_(owner),
53         last_append_sample_(0)
54 {
55         lock_guard<recursive_mutex> lock(mutex_);
56         memset(mip_map_, 0, sizeof(mip_map_));
57         append_payload(data);
58 }
59
60 LogicSegment::~LogicSegment()
61 {
62         lock_guard<recursive_mutex> lock(mutex_);
63         for (MipMapLevel &l : mip_map_)
64                 free(l.data);
65 }
66
67 uint64_t LogicSegment::unpack_sample(const uint8_t *ptr) const
68 {
69 #ifdef HAVE_UNALIGNED_LITTLE_ENDIAN_ACCESS
70         return *(uint64_t*)ptr;
71 #else
72         uint64_t value = 0;
73         switch (unit_size_) {
74         default:
75                 value |= ((uint64_t)ptr[7]) << 56;
76                 /* FALLTHRU */
77         case 7:
78                 value |= ((uint64_t)ptr[6]) << 48;
79                 /* FALLTHRU */
80         case 6:
81                 value |= ((uint64_t)ptr[5]) << 40;
82                 /* FALLTHRU */
83         case 5:
84                 value |= ((uint64_t)ptr[4]) << 32;
85                 /* FALLTHRU */
86         case 4:
87                 value |= ((uint32_t)ptr[3]) << 24;
88                 /* FALLTHRU */
89         case 3:
90                 value |= ((uint32_t)ptr[2]) << 16;
91                 /* FALLTHRU */
92         case 2:
93                 value |= ptr[1] << 8;
94                 /* FALLTHRU */
95         case 1:
96                 value |= ptr[0];
97                 /* FALLTHRU */
98         case 0:
99                 break;
100         }
101         return value;
102 #endif
103 }
104
105 void LogicSegment::pack_sample(uint8_t *ptr, uint64_t value)
106 {
107 #ifdef HAVE_UNALIGNED_LITTLE_ENDIAN_ACCESS
108         *(uint64_t*)ptr = value;
109 #else
110         switch (unit_size_) {
111         default:
112                 ptr[7] = value >> 56;
113                 /* FALLTHRU */
114         case 7:
115                 ptr[6] = value >> 48;
116                 /* FALLTHRU */
117         case 6:
118                 ptr[5] = value >> 40;
119                 /* FALLTHRU */
120         case 5:
121                 ptr[4] = value >> 32;
122                 /* FALLTHRU */
123         case 4:
124                 ptr[3] = value >> 24;
125                 /* FALLTHRU */
126         case 3:
127                 ptr[2] = value >> 16;
128                 /* FALLTHRU */
129         case 2:
130                 ptr[1] = value >> 8;
131                 /* FALLTHRU */
132         case 1:
133                 ptr[0] = value;
134                 /* FALLTHRU */
135         case 0:
136                 break;
137         }
138 #endif
139 }
140
141 void LogicSegment::append_payload(shared_ptr<sigrok::Logic> logic)
142 {
143         assert(unit_size_ == logic->unit_size());
144         assert((logic->data_length() % unit_size_) == 0);
145
146         lock_guard<recursive_mutex> lock(mutex_);
147
148         uint64_t prev_sample_count = sample_count_;
149         uint64_t sample_count = logic->data_length() / unit_size_;
150
151         append_samples(logic->data_pointer(), sample_count);
152
153         // Generate the first mip-map from the data
154         append_payload_to_mipmap();
155
156         if (sample_count > 1)
157                 owner_.notify_samples_added(this, prev_sample_count + 1,
158                         prev_sample_count + 1 + sample_count);
159         else
160                 owner_.notify_samples_added(this, prev_sample_count + 1,
161                         prev_sample_count + 1);
162 }
163
164 const uint8_t* LogicSegment::get_samples(int64_t start_sample,
165         int64_t end_sample) const
166 {
167         assert(start_sample >= 0);
168         assert(start_sample <= (int64_t)sample_count_);
169         assert(end_sample >= 0);
170         assert(end_sample <= (int64_t)sample_count_);
171         assert(start_sample <= end_sample);
172
173         lock_guard<recursive_mutex> lock(mutex_);
174
175         return get_raw_samples(start_sample, (end_sample-start_sample));
176 }
177
178 SegmentLogicDataIterator* LogicSegment::begin_sample_iteration(uint64_t start)
179 {
180         return (SegmentLogicDataIterator*)begin_raw_sample_iteration(start);
181 }
182
183 void LogicSegment::continue_sample_iteration(SegmentLogicDataIterator* it, uint64_t increase)
184 {
185         Segment::continue_raw_sample_iteration((SegmentRawDataIterator*)it, increase);
186 }
187
188 void LogicSegment::end_sample_iteration(SegmentLogicDataIterator* it)
189 {
190         Segment::end_raw_sample_iteration((SegmentRawDataIterator*)it);
191 }
192
193 void LogicSegment::reallocate_mipmap_level(MipMapLevel &m)
194 {
195         lock_guard<recursive_mutex> lock(mutex_);
196
197         const uint64_t new_data_length = ((m.length + MipMapDataUnit - 1) /
198                 MipMapDataUnit) * MipMapDataUnit;
199
200         if (new_data_length > m.data_length) {
201                 m.data_length = new_data_length;
202
203                 // Padding is added to allow for the uint64_t write word
204                 m.data = realloc(m.data, new_data_length * unit_size_ +
205                         sizeof(uint64_t));
206         }
207 }
208
209 void LogicSegment::append_payload_to_mipmap()
210 {
211         MipMapLevel &m0 = mip_map_[0];
212         uint64_t prev_length;
213         uint8_t *dest_ptr;
214         SegmentRawDataIterator* it;
215         uint64_t accumulator;
216         unsigned int diff_counter;
217
218         // Expand the data buffer to fit the new samples
219         prev_length = m0.length;
220         m0.length = sample_count_ / MipMapScaleFactor;
221
222         // Break off if there are no new samples to compute
223         if (m0.length == prev_length)
224                 return;
225
226         reallocate_mipmap_level(m0);
227
228         dest_ptr = (uint8_t*)m0.data + prev_length * unit_size_;
229
230         // Iterate through the samples to populate the first level mipmap
231         uint64_t start_sample = prev_length * MipMapScaleFactor;
232         uint64_t end_sample = m0.length * MipMapScaleFactor;
233
234         it = begin_raw_sample_iteration(start_sample);
235         for (uint64_t i = start_sample; i < end_sample;) {
236                 // Accumulate transitions which have occurred in this sample
237                 accumulator = 0;
238                 diff_counter = MipMapScaleFactor;
239                 while (diff_counter-- > 0) {
240                         const uint64_t sample = unpack_sample(it->value);
241                         accumulator |= last_append_sample_ ^ sample;
242                         last_append_sample_ = sample;
243                         continue_raw_sample_iteration(it, 1);
244                         i++;
245                 }
246
247                 pack_sample(dest_ptr, accumulator);
248                 dest_ptr += unit_size_;
249         }
250         end_raw_sample_iteration(it);
251
252         // Compute higher level mipmaps
253         for (unsigned int level = 1; level < ScaleStepCount; level++) {
254                 MipMapLevel &m = mip_map_[level];
255                 const MipMapLevel &ml = mip_map_[level-1];
256
257                 // Expand the data buffer to fit the new samples
258                 prev_length = m.length;
259                 m.length = ml.length / MipMapScaleFactor;
260
261                 // Break off if there are no more samples to be computed
262                 if (m.length == prev_length)
263                         break;
264
265                 reallocate_mipmap_level(m);
266
267                 // Subsample the lower level
268                 const uint8_t* src_ptr = (uint8_t*)ml.data +
269                         unit_size_ * prev_length * MipMapScaleFactor;
270                 const uint8_t *const end_dest_ptr =
271                         (uint8_t*)m.data + unit_size_ * m.length;
272
273                 for (dest_ptr = (uint8_t*)m.data +
274                                 unit_size_ * prev_length;
275                                 dest_ptr < end_dest_ptr;
276                                 dest_ptr += unit_size_) {
277                         accumulator = 0;
278                         diff_counter = MipMapScaleFactor;
279                         while (diff_counter-- > 0) {
280                                 accumulator |= unpack_sample(src_ptr);
281                                 src_ptr += unit_size_;
282                         }
283
284                         pack_sample(dest_ptr, accumulator);
285                 }
286         }
287 }
288
289 uint64_t LogicSegment::get_unpacked_sample(uint64_t index) const
290 {
291         assert(index < sample_count_);
292
293         const uint8_t* data = get_raw_samples(index, 1);
294         uint64_t sample = unpack_sample(data);
295         delete[] data;
296
297         return sample;
298 }
299
300 void LogicSegment::get_subsampled_edges(
301         std::vector<EdgePair> &edges,
302         uint64_t start, uint64_t end,
303         float min_length, int sig_index)
304 {
305         uint64_t index = start;
306         unsigned int level;
307         bool last_sample;
308         bool fast_forward;
309
310         assert(end <= get_sample_count());
311         assert(start <= end);
312         assert(min_length > 0);
313         assert(sig_index >= 0);
314         assert(sig_index < 64);
315
316         lock_guard<recursive_mutex> lock(mutex_);
317
318         const uint64_t block_length = (uint64_t)max(min_length, 1.0f);
319         const unsigned int min_level = max((int)floorf(logf(min_length) /
320                 LogMipMapScaleFactor) - 1, 0);
321         const uint64_t sig_mask = 1ULL << sig_index;
322
323         // Store the initial state
324         last_sample = (get_unpacked_sample(start) & sig_mask) != 0;
325         edges.push_back(pair<int64_t, bool>(index++, last_sample));
326
327         while (index + block_length <= end) {
328                 //----- Continue to search -----//
329                 level = min_level;
330
331                 // We cannot fast-forward if there is no mip-map data at
332                 // at the minimum level.
333                 fast_forward = (mip_map_[level].data != nullptr);
334
335                 if (min_length < MipMapScaleFactor) {
336                         // Search individual samples up to the beginning of
337                         // the next first level mip map block
338                         const uint64_t final_index = min(end,
339                                 pow2_ceil(index, MipMapScalePower));
340
341                         for (; index < final_index &&
342                                         (index & ~((uint64_t)(~0) << MipMapScalePower)) != 0;
343                                         index++) {
344                                 const bool sample =
345                                         (get_unpacked_sample(index) & sig_mask) != 0;
346
347                                 // If there was a change we cannot fast forward
348                                 if (sample != last_sample) {
349                                         fast_forward = false;
350                                         break;
351                                 }
352                         }
353                 } else {
354                         // If resolution is less than a mip map block,
355                         // round up to the beginning of the mip-map block
356                         // for this level of detail
357                         const int min_level_scale_power =
358                                 (level + 1) * MipMapScalePower;
359                         index = pow2_ceil(index, min_level_scale_power);
360                         if (index >= end)
361                                 break;
362
363                         // We can fast forward only if there was no change
364                         const bool sample =
365                                 (get_unpacked_sample(index) & sig_mask) != 0;
366                         if (last_sample != sample)
367                                 fast_forward = false;
368                 }
369
370                 if (fast_forward) {
371
372                         // Fast forward: This involves zooming out to higher
373                         // levels of the mip map searching for changes, then
374                         // zooming in on them to find the point where the edge
375                         // begins.
376
377                         // Slide right and zoom out at the beginnings of mip-map
378                         // blocks until we encounter a change
379                         while (1) {
380                                 const int level_scale_power =
381                                         (level + 1) * MipMapScalePower;
382                                 const uint64_t offset =
383                                         index >> level_scale_power;
384
385                                 // Check if we reached the last block at this
386                                 // level, or if there was a change in this block
387                                 if (offset >= mip_map_[level].length ||
388                                         (get_subsample(level, offset) &
389                                                 sig_mask))
390                                         break;
391
392                                 if ((offset & ~((uint64_t)(~0) << MipMapScalePower)) == 0) {
393                                         // If we are now at the beginning of a
394                                         // higher level mip-map block ascend one
395                                         // level
396                                         if (level + 1 >= ScaleStepCount ||
397                                                 !mip_map_[level + 1].data)
398                                                 break;
399
400                                         level++;
401                                 } else {
402                                         // Slide right to the beginning of the
403                                         // next mip map block
404                                         index = pow2_ceil(index + 1,
405                                                 level_scale_power);
406                                 }
407                         }
408
409                         // Zoom in, and slide right until we encounter a change,
410                         // and repeat until we reach min_level
411                         while (1) {
412                                 assert(mip_map_[level].data);
413
414                                 const int level_scale_power =
415                                         (level + 1) * MipMapScalePower;
416                                 const uint64_t offset =
417                                         index >> level_scale_power;
418
419                                 // Check if we reached the last block at this
420                                 // level, or if there was a change in this block
421                                 if (offset >= mip_map_[level].length ||
422                                                 (get_subsample(level, offset) &
423                                                 sig_mask)) {
424                                         // Zoom in unless we reached the minimum
425                                         // zoom
426                                         if (level == min_level)
427                                                 break;
428
429                                         level--;
430                                 } else {
431                                         // Slide right to the beginning of the
432                                         // next mip map block
433                                         index = pow2_ceil(index + 1,
434                                                 level_scale_power);
435                                 }
436                         }
437
438                         // If individual samples within the limit of resolution,
439                         // do a linear search for the next transition within the
440                         // block
441                         if (min_length < MipMapScaleFactor) {
442                                 for (; index < end; index++) {
443                                         const bool sample = (get_unpacked_sample(index) &
444                                                 sig_mask) != 0;
445                                         if (sample != last_sample)
446                                                 break;
447                                 }
448                         }
449                 }
450
451                 //----- Store the edge -----//
452
453                 // Take the last sample of the quanization block
454                 const int64_t final_index = index + block_length;
455                 if (index + block_length > end)
456                         break;
457
458                 // Store the final state
459                 const bool final_sample =
460                         (get_unpacked_sample(final_index - 1) & sig_mask) != 0;
461                 edges.push_back(pair<int64_t, bool>(index, final_sample));
462
463                 index = final_index;
464                 last_sample = final_sample;
465         }
466
467         // Add the final state
468         const bool end_sample = get_unpacked_sample(end) & sig_mask;
469         if (last_sample != end_sample)
470                 edges.push_back(pair<int64_t, bool>(end, end_sample));
471         edges.push_back(pair<int64_t, bool>(end + 1, end_sample));
472 }
473
474 uint64_t LogicSegment::get_subsample(int level, uint64_t offset) const
475 {
476         assert(level >= 0);
477         assert(mip_map_[level].data);
478         return unpack_sample((uint8_t*)mip_map_[level].data +
479                 unit_size_ * offset);
480 }
481
482 uint64_t LogicSegment::pow2_ceil(uint64_t x, unsigned int power)
483 {
484         const uint64_t p = 1 << power;
485         return (x + p - 1) / p * p;
486 }
487
488 } // namespace data
489 } // namespace pv