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