1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 // Histogram is an object that aggregates statistics, and can summarize them in 6 // various forms, including ASCII graphical, HTML, and numerically (as a 7 // vector of numbers corresponding to each of the aggregating buckets). 8 // See header file for details and examples. 9 10 #include "base/metrics/histogram.h" 11 12 #include <math.h> 13 14 #include <algorithm> 15 #include <string> 16 17 #include "base/compiler_specific.h" 18 #include "base/debug/alias.h" 19 #include "base/logging.h" 20 #include "base/metrics/sample_vector.h" 21 #include "base/metrics/statistics_recorder.h" 22 #include "base/pickle.h" 23 #include "base/strings/string_util.h" 24 #include "base/strings/stringprintf.h" 25 #include "base/synchronization/lock.h" 26 #include "base/values.h" 27 28 using std::string; 29 using std::vector; 30 31 namespace base { 32 33 namespace { 34 35 bool ReadHistogramArguments(PickleIterator* iter, 36 string* histogram_name, 37 int* flags, 38 int* declared_min, 39 int* declared_max, 40 uint64* bucket_count, 41 uint32* range_checksum) { 42 if (!iter->ReadString(histogram_name) || 43 !iter->ReadInt(flags) || 44 !iter->ReadInt(declared_min) || 45 !iter->ReadInt(declared_max) || 46 !iter->ReadUInt64(bucket_count) || 47 !iter->ReadUInt32(range_checksum)) { 48 DLOG(ERROR) << "Pickle error decoding Histogram: " << *histogram_name; 49 return false; 50 } 51 52 // Since these fields may have come from an untrusted renderer, do additional 53 // checks above and beyond those in Histogram::Initialize() 54 if (*declared_max <= 0 || 55 *declared_min <= 0 || 56 *declared_max < *declared_min || 57 INT_MAX / sizeof(HistogramBase::Count) <= *bucket_count || 58 *bucket_count < 2) { 59 DLOG(ERROR) << "Values error decoding Histogram: " << histogram_name; 60 return false; 61 } 62 63 // We use the arguments to find or create the local version of the histogram 64 // in this process, so we need to clear the IPC flag. 65 DCHECK(*flags & HistogramBase::kIPCSerializationSourceFlag); 66 *flags &= ~HistogramBase::kIPCSerializationSourceFlag; 67 68 return true; 69 } 70 71 bool ValidateRangeChecksum(const HistogramBase& histogram, 72 uint32 range_checksum) { 73 const Histogram& casted_histogram = 74 static_cast<const Histogram&>(histogram); 75 76 return casted_histogram.bucket_ranges()->checksum() == range_checksum; 77 } 78 79 } // namespace 80 81 typedef HistogramBase::Count Count; 82 typedef HistogramBase::Sample Sample; 83 84 // static 85 const size_t Histogram::kBucketCount_MAX = 16384u; 86 87 HistogramBase* Histogram::FactoryGet(const string& name, 88 Sample minimum, 89 Sample maximum, 90 size_t bucket_count, 91 int32 flags) { 92 bool valid_arguments = 93 InspectConstructionArguments(name, &minimum, &maximum, &bucket_count); 94 DCHECK(valid_arguments); 95 96 HistogramBase* histogram = StatisticsRecorder::FindHistogram(name); 97 if (!histogram) { 98 // To avoid racy destruction at shutdown, the following will be leaked. 99 BucketRanges* ranges = new BucketRanges(bucket_count + 1); 100 InitializeBucketRanges(minimum, maximum, ranges); 101 const BucketRanges* registered_ranges = 102 StatisticsRecorder::RegisterOrDeleteDuplicateRanges(ranges); 103 104 Histogram* tentative_histogram = 105 new Histogram(name, minimum, maximum, registered_ranges); 106 107 tentative_histogram->SetFlags(flags); 108 histogram = 109 StatisticsRecorder::RegisterOrDeleteDuplicate(tentative_histogram); 110 } 111 112 DCHECK_EQ(HISTOGRAM, histogram->GetHistogramType()); 113 CHECK(histogram->HasConstructionArguments(minimum, maximum, bucket_count)); 114 return histogram; 115 } 116 117 HistogramBase* Histogram::FactoryTimeGet(const string& name, 118 TimeDelta minimum, 119 TimeDelta maximum, 120 size_t bucket_count, 121 int32 flags) { 122 return FactoryGet(name, minimum.InMilliseconds(), maximum.InMilliseconds(), 123 bucket_count, flags); 124 } 125 126 TimeTicks Histogram::DebugNow() { 127 #ifndef NDEBUG 128 return TimeTicks::Now(); 129 #else 130 return TimeTicks(); 131 #endif 132 } 133 134 // Calculate what range of values are held in each bucket. 135 // We have to be careful that we don't pick a ratio between starting points in 136 // consecutive buckets that is sooo small, that the integer bounds are the same 137 // (effectively making one bucket get no values). We need to avoid: 138 // ranges(i) == ranges(i + 1) 139 // To avoid that, we just do a fine-grained bucket width as far as we need to 140 // until we get a ratio that moves us along at least 2 units at a time. From 141 // that bucket onward we do use the exponential growth of buckets. 142 // 143 // static 144 void Histogram::InitializeBucketRanges(Sample minimum, 145 Sample maximum, 146 BucketRanges* ranges) { 147 double log_max = log(static_cast<double>(maximum)); 148 double log_ratio; 149 double log_next; 150 size_t bucket_index = 1; 151 Sample current = minimum; 152 ranges->set_range(bucket_index, current); 153 size_t bucket_count = ranges->bucket_count(); 154 while (bucket_count > ++bucket_index) { 155 double log_current; 156 log_current = log(static_cast<double>(current)); 157 // Calculate the count'th root of the range. 158 log_ratio = (log_max - log_current) / (bucket_count - bucket_index); 159 // See where the next bucket would start. 160 log_next = log_current + log_ratio; 161 Sample next; 162 next = static_cast<int>(floor(exp(log_next) + 0.5)); 163 if (next > current) 164 current = next; 165 else 166 ++current; // Just do a narrow bucket, and keep trying. 167 ranges->set_range(bucket_index, current); 168 } 169 ranges->set_range(ranges->bucket_count(), HistogramBase::kSampleType_MAX); 170 ranges->ResetChecksum(); 171 } 172 173 // static 174 const int Histogram::kCommonRaceBasedCountMismatch = 5; 175 176 int Histogram::FindCorruption(const HistogramSamples& samples) const { 177 int inconsistencies = NO_INCONSISTENCIES; 178 Sample previous_range = -1; // Bottom range is always 0. 179 for (size_t index = 0; index < bucket_count(); ++index) { 180 int new_range = ranges(index); 181 if (previous_range >= new_range) 182 inconsistencies |= BUCKET_ORDER_ERROR; 183 previous_range = new_range; 184 } 185 186 if (!bucket_ranges()->HasValidChecksum()) 187 inconsistencies |= RANGE_CHECKSUM_ERROR; 188 189 int64 delta64 = samples.redundant_count() - samples.TotalCount(); 190 if (delta64 != 0) { 191 int delta = static_cast<int>(delta64); 192 if (delta != delta64) 193 delta = INT_MAX; // Flag all giant errors as INT_MAX. 194 if (delta > 0) { 195 UMA_HISTOGRAM_COUNTS("Histogram.InconsistentCountHigh", delta); 196 if (delta > kCommonRaceBasedCountMismatch) 197 inconsistencies |= COUNT_HIGH_ERROR; 198 } else { 199 DCHECK_GT(0, delta); 200 UMA_HISTOGRAM_COUNTS("Histogram.InconsistentCountLow", -delta); 201 if (-delta > kCommonRaceBasedCountMismatch) 202 inconsistencies |= COUNT_LOW_ERROR; 203 } 204 } 205 return inconsistencies; 206 } 207 208 Sample Histogram::ranges(size_t i) const { 209 return bucket_ranges_->range(i); 210 } 211 212 size_t Histogram::bucket_count() const { 213 return bucket_ranges_->bucket_count(); 214 } 215 216 // static 217 bool Histogram::InspectConstructionArguments(const string& name, 218 Sample* minimum, 219 Sample* maximum, 220 size_t* bucket_count) { 221 // Defensive code for backward compatibility. 222 if (*minimum < 1) { 223 DVLOG(1) << "Histogram: " << name << " has bad minimum: " << *minimum; 224 *minimum = 1; 225 } 226 if (*maximum >= kSampleType_MAX) { 227 DVLOG(1) << "Histogram: " << name << " has bad maximum: " << *maximum; 228 *maximum = kSampleType_MAX - 1; 229 } 230 if (*bucket_count >= kBucketCount_MAX) { 231 DVLOG(1) << "Histogram: " << name << " has bad bucket_count: " 232 << *bucket_count; 233 *bucket_count = kBucketCount_MAX - 1; 234 } 235 236 if (*minimum >= *maximum) 237 return false; 238 if (*bucket_count < 3) 239 return false; 240 if (*bucket_count > static_cast<size_t>(*maximum - *minimum + 2)) 241 return false; 242 return true; 243 } 244 245 HistogramType Histogram::GetHistogramType() const { 246 return HISTOGRAM; 247 } 248 249 bool Histogram::HasConstructionArguments(Sample expected_minimum, 250 Sample expected_maximum, 251 size_t expected_bucket_count) const { 252 return ((expected_minimum == declared_min_) && 253 (expected_maximum == declared_max_) && 254 (expected_bucket_count == bucket_count())); 255 } 256 257 void Histogram::Add(int value) { 258 DCHECK_EQ(0, ranges(0)); 259 DCHECK_EQ(kSampleType_MAX, ranges(bucket_count())); 260 261 if (value > kSampleType_MAX - 1) 262 value = kSampleType_MAX - 1; 263 if (value < 0) 264 value = 0; 265 samples_->Accumulate(value, 1); 266 } 267 268 scoped_ptr<HistogramSamples> Histogram::SnapshotSamples() const { 269 return SnapshotSampleVector().PassAs<HistogramSamples>(); 270 } 271 272 void Histogram::AddSamples(const HistogramSamples& samples) { 273 samples_->Add(samples); 274 } 275 276 bool Histogram::AddSamplesFromPickle(PickleIterator* iter) { 277 return samples_->AddFromPickle(iter); 278 } 279 280 // The following methods provide a graphical histogram display. 281 void Histogram::WriteHTMLGraph(string* output) const { 282 // TBD(jar) Write a nice HTML bar chart, with divs an mouse-overs etc. 283 output->append("<PRE>"); 284 WriteAsciiImpl(true, "<br>", output); 285 output->append("</PRE>"); 286 } 287 288 void Histogram::WriteAscii(string* output) const { 289 WriteAsciiImpl(true, "\n", output); 290 } 291 292 bool Histogram::SerializeInfoImpl(Pickle* pickle) const { 293 DCHECK(bucket_ranges()->HasValidChecksum()); 294 return pickle->WriteString(histogram_name()) && 295 pickle->WriteInt(flags()) && 296 pickle->WriteInt(declared_min()) && 297 pickle->WriteInt(declared_max()) && 298 pickle->WriteUInt64(bucket_count()) && 299 pickle->WriteUInt32(bucket_ranges()->checksum()); 300 } 301 302 Histogram::Histogram(const string& name, 303 Sample minimum, 304 Sample maximum, 305 const BucketRanges* ranges) 306 : HistogramBase(name), 307 bucket_ranges_(ranges), 308 declared_min_(minimum), 309 declared_max_(maximum) { 310 if (ranges) 311 samples_.reset(new SampleVector(ranges)); 312 } 313 314 Histogram::~Histogram() { 315 } 316 317 bool Histogram::PrintEmptyBucket(size_t index) const { 318 return true; 319 } 320 321 // Use the actual bucket widths (like a linear histogram) until the widths get 322 // over some transition value, and then use that transition width. Exponentials 323 // get so big so fast (and we don't expect to see a lot of entries in the large 324 // buckets), so we need this to make it possible to see what is going on and 325 // not have 0-graphical-height buckets. 326 double Histogram::GetBucketSize(Count current, size_t i) const { 327 DCHECK_GT(ranges(i + 1), ranges(i)); 328 static const double kTransitionWidth = 5; 329 double denominator = ranges(i + 1) - ranges(i); 330 if (denominator > kTransitionWidth) 331 denominator = kTransitionWidth; // Stop trying to normalize. 332 return current/denominator; 333 } 334 335 const string Histogram::GetAsciiBucketRange(size_t i) const { 336 return GetSimpleAsciiBucketRange(ranges(i)); 337 } 338 339 //------------------------------------------------------------------------------ 340 // Private methods 341 342 // static 343 HistogramBase* Histogram::DeserializeInfoImpl(PickleIterator* iter) { 344 string histogram_name; 345 int flags; 346 int declared_min; 347 int declared_max; 348 uint64 bucket_count; 349 uint32 range_checksum; 350 351 if (!ReadHistogramArguments(iter, &histogram_name, &flags, &declared_min, 352 &declared_max, &bucket_count, &range_checksum)) { 353 return NULL; 354 } 355 356 // Find or create the local version of the histogram in this process. 357 HistogramBase* histogram = Histogram::FactoryGet( 358 histogram_name, declared_min, declared_max, bucket_count, flags); 359 360 if (!ValidateRangeChecksum(*histogram, range_checksum)) { 361 // The serialized histogram might be corrupted. 362 return NULL; 363 } 364 return histogram; 365 } 366 367 scoped_ptr<SampleVector> Histogram::SnapshotSampleVector() const { 368 scoped_ptr<SampleVector> samples(new SampleVector(bucket_ranges())); 369 samples->Add(*samples_); 370 return samples.Pass(); 371 } 372 373 void Histogram::WriteAsciiImpl(bool graph_it, 374 const string& newline, 375 string* output) const { 376 // Get local (stack) copies of all effectively volatile class data so that we 377 // are consistent across our output activities. 378 scoped_ptr<SampleVector> snapshot = SnapshotSampleVector(); 379 Count sample_count = snapshot->TotalCount(); 380 381 WriteAsciiHeader(*snapshot, sample_count, output); 382 output->append(newline); 383 384 // Prepare to normalize graphical rendering of bucket contents. 385 double max_size = 0; 386 if (graph_it) 387 max_size = GetPeakBucketSize(*snapshot); 388 389 // Calculate space needed to print bucket range numbers. Leave room to print 390 // nearly the largest bucket range without sliding over the histogram. 391 size_t largest_non_empty_bucket = bucket_count() - 1; 392 while (0 == snapshot->GetCountAtIndex(largest_non_empty_bucket)) { 393 if (0 == largest_non_empty_bucket) 394 break; // All buckets are empty. 395 --largest_non_empty_bucket; 396 } 397 398 // Calculate largest print width needed for any of our bucket range displays. 399 size_t print_width = 1; 400 for (size_t i = 0; i < bucket_count(); ++i) { 401 if (snapshot->GetCountAtIndex(i)) { 402 size_t width = GetAsciiBucketRange(i).size() + 1; 403 if (width > print_width) 404 print_width = width; 405 } 406 } 407 408 int64 remaining = sample_count; 409 int64 past = 0; 410 // Output the actual histogram graph. 411 for (size_t i = 0; i < bucket_count(); ++i) { 412 Count current = snapshot->GetCountAtIndex(i); 413 if (!current && !PrintEmptyBucket(i)) 414 continue; 415 remaining -= current; 416 string range = GetAsciiBucketRange(i); 417 output->append(range); 418 for (size_t j = 0; range.size() + j < print_width + 1; ++j) 419 output->push_back(' '); 420 if (0 == current && i < bucket_count() - 1 && 421 0 == snapshot->GetCountAtIndex(i + 1)) { 422 while (i < bucket_count() - 1 && 423 0 == snapshot->GetCountAtIndex(i + 1)) { 424 ++i; 425 } 426 output->append("... "); 427 output->append(newline); 428 continue; // No reason to plot emptiness. 429 } 430 double current_size = GetBucketSize(current, i); 431 if (graph_it) 432 WriteAsciiBucketGraph(current_size, max_size, output); 433 WriteAsciiBucketContext(past, current, remaining, i, output); 434 output->append(newline); 435 past += current; 436 } 437 DCHECK_EQ(sample_count, past); 438 } 439 440 double Histogram::GetPeakBucketSize(const SampleVector& samples) const { 441 double max = 0; 442 for (size_t i = 0; i < bucket_count() ; ++i) { 443 double current_size = GetBucketSize(samples.GetCountAtIndex(i), i); 444 if (current_size > max) 445 max = current_size; 446 } 447 return max; 448 } 449 450 void Histogram::WriteAsciiHeader(const SampleVector& samples, 451 Count sample_count, 452 string* output) const { 453 StringAppendF(output, 454 "Histogram: %s recorded %d samples", 455 histogram_name().c_str(), 456 sample_count); 457 if (0 == sample_count) { 458 DCHECK_EQ(samples.sum(), 0); 459 } else { 460 double average = static_cast<float>(samples.sum()) / sample_count; 461 462 StringAppendF(output, ", average = %.1f", average); 463 } 464 if (flags() & ~kHexRangePrintingFlag) 465 StringAppendF(output, " (flags = 0x%x)", flags() & ~kHexRangePrintingFlag); 466 } 467 468 void Histogram::WriteAsciiBucketContext(const int64 past, 469 const Count current, 470 const int64 remaining, 471 const size_t i, 472 string* output) const { 473 double scaled_sum = (past + current + remaining) / 100.0; 474 WriteAsciiBucketValue(current, scaled_sum, output); 475 if (0 < i) { 476 double percentage = past / scaled_sum; 477 StringAppendF(output, " {%3.1f%%}", percentage); 478 } 479 } 480 481 void Histogram::GetParameters(DictionaryValue* params) const { 482 params->SetString("type", HistogramTypeToString(GetHistogramType())); 483 params->SetInteger("min", declared_min()); 484 params->SetInteger("max", declared_max()); 485 params->SetInteger("bucket_count", static_cast<int>(bucket_count())); 486 } 487 488 void Histogram::GetCountAndBucketData(Count* count, 489 int64* sum, 490 ListValue* buckets) const { 491 scoped_ptr<SampleVector> snapshot = SnapshotSampleVector(); 492 *count = snapshot->TotalCount(); 493 *sum = snapshot->sum(); 494 size_t index = 0; 495 for (size_t i = 0; i < bucket_count(); ++i) { 496 Sample count = snapshot->GetCountAtIndex(i); 497 if (count > 0) { 498 scoped_ptr<DictionaryValue> bucket_value(new DictionaryValue()); 499 bucket_value->SetInteger("low", ranges(i)); 500 if (i != bucket_count() - 1) 501 bucket_value->SetInteger("high", ranges(i + 1)); 502 bucket_value->SetInteger("count", count); 503 buckets->Set(index, bucket_value.release()); 504 ++index; 505 } 506 } 507 } 508 509 //------------------------------------------------------------------------------ 510 // LinearHistogram: This histogram uses a traditional set of evenly spaced 511 // buckets. 512 //------------------------------------------------------------------------------ 513 514 LinearHistogram::~LinearHistogram() {} 515 516 HistogramBase* LinearHistogram::FactoryGet(const string& name, 517 Sample minimum, 518 Sample maximum, 519 size_t bucket_count, 520 int32 flags) { 521 return FactoryGetWithRangeDescription( 522 name, minimum, maximum, bucket_count, flags, NULL); 523 } 524 525 HistogramBase* LinearHistogram::FactoryTimeGet(const string& name, 526 TimeDelta minimum, 527 TimeDelta maximum, 528 size_t bucket_count, 529 int32 flags) { 530 return FactoryGet(name, minimum.InMilliseconds(), maximum.InMilliseconds(), 531 bucket_count, flags); 532 } 533 534 HistogramBase* LinearHistogram::FactoryGetWithRangeDescription( 535 const std::string& name, 536 Sample minimum, 537 Sample maximum, 538 size_t bucket_count, 539 int32 flags, 540 const DescriptionPair descriptions[]) { 541 bool valid_arguments = Histogram::InspectConstructionArguments( 542 name, &minimum, &maximum, &bucket_count); 543 DCHECK(valid_arguments); 544 545 HistogramBase* histogram = StatisticsRecorder::FindHistogram(name); 546 if (!histogram) { 547 // To avoid racy destruction at shutdown, the following will be leaked. 548 BucketRanges* ranges = new BucketRanges(bucket_count + 1); 549 InitializeBucketRanges(minimum, maximum, ranges); 550 const BucketRanges* registered_ranges = 551 StatisticsRecorder::RegisterOrDeleteDuplicateRanges(ranges); 552 553 LinearHistogram* tentative_histogram = 554 new LinearHistogram(name, minimum, maximum, registered_ranges); 555 556 // Set range descriptions. 557 if (descriptions) { 558 for (int i = 0; descriptions[i].description; ++i) { 559 tentative_histogram->bucket_description_[descriptions[i].sample] = 560 descriptions[i].description; 561 } 562 } 563 564 tentative_histogram->SetFlags(flags); 565 histogram = 566 StatisticsRecorder::RegisterOrDeleteDuplicate(tentative_histogram); 567 } 568 569 DCHECK_EQ(LINEAR_HISTOGRAM, histogram->GetHistogramType()); 570 CHECK(histogram->HasConstructionArguments(minimum, maximum, bucket_count)); 571 return histogram; 572 } 573 574 HistogramType LinearHistogram::GetHistogramType() const { 575 return LINEAR_HISTOGRAM; 576 } 577 578 LinearHistogram::LinearHistogram(const string& name, 579 Sample minimum, 580 Sample maximum, 581 const BucketRanges* ranges) 582 : Histogram(name, minimum, maximum, ranges) { 583 } 584 585 double LinearHistogram::GetBucketSize(Count current, size_t i) const { 586 DCHECK_GT(ranges(i + 1), ranges(i)); 587 // Adjacent buckets with different widths would have "surprisingly" many (few) 588 // samples in a histogram if we didn't normalize this way. 589 double denominator = ranges(i + 1) - ranges(i); 590 return current/denominator; 591 } 592 593 const string LinearHistogram::GetAsciiBucketRange(size_t i) const { 594 int range = ranges(i); 595 BucketDescriptionMap::const_iterator it = bucket_description_.find(range); 596 if (it == bucket_description_.end()) 597 return Histogram::GetAsciiBucketRange(i); 598 return it->second; 599 } 600 601 bool LinearHistogram::PrintEmptyBucket(size_t index) const { 602 return bucket_description_.find(ranges(index)) == bucket_description_.end(); 603 } 604 605 // static 606 void LinearHistogram::InitializeBucketRanges(Sample minimum, 607 Sample maximum, 608 BucketRanges* ranges) { 609 double min = minimum; 610 double max = maximum; 611 size_t bucket_count = ranges->bucket_count(); 612 for (size_t i = 1; i < bucket_count; ++i) { 613 double linear_range = 614 (min * (bucket_count - 1 - i) + max * (i - 1)) / (bucket_count - 2); 615 ranges->set_range(i, static_cast<Sample>(linear_range + 0.5)); 616 } 617 ranges->set_range(ranges->bucket_count(), HistogramBase::kSampleType_MAX); 618 ranges->ResetChecksum(); 619 } 620 621 // static 622 HistogramBase* LinearHistogram::DeserializeInfoImpl(PickleIterator* iter) { 623 string histogram_name; 624 int flags; 625 int declared_min; 626 int declared_max; 627 uint64 bucket_count; 628 uint32 range_checksum; 629 630 if (!ReadHistogramArguments(iter, &histogram_name, &flags, &declared_min, 631 &declared_max, &bucket_count, &range_checksum)) { 632 return NULL; 633 } 634 635 HistogramBase* histogram = LinearHistogram::FactoryGet( 636 histogram_name, declared_min, declared_max, bucket_count, flags); 637 if (!ValidateRangeChecksum(*histogram, range_checksum)) { 638 // The serialized histogram might be corrupted. 639 return NULL; 640 } 641 return histogram; 642 } 643 644 //------------------------------------------------------------------------------ 645 // This section provides implementation for BooleanHistogram. 646 //------------------------------------------------------------------------------ 647 648 HistogramBase* BooleanHistogram::FactoryGet(const string& name, int32 flags) { 649 HistogramBase* histogram = StatisticsRecorder::FindHistogram(name); 650 if (!histogram) { 651 // To avoid racy destruction at shutdown, the following will be leaked. 652 BucketRanges* ranges = new BucketRanges(4); 653 LinearHistogram::InitializeBucketRanges(1, 2, ranges); 654 const BucketRanges* registered_ranges = 655 StatisticsRecorder::RegisterOrDeleteDuplicateRanges(ranges); 656 657 BooleanHistogram* tentative_histogram = 658 new BooleanHistogram(name, registered_ranges); 659 660 tentative_histogram->SetFlags(flags); 661 histogram = 662 StatisticsRecorder::RegisterOrDeleteDuplicate(tentative_histogram); 663 } 664 665 DCHECK_EQ(BOOLEAN_HISTOGRAM, histogram->GetHistogramType()); 666 return histogram; 667 } 668 669 HistogramType BooleanHistogram::GetHistogramType() const { 670 return BOOLEAN_HISTOGRAM; 671 } 672 673 BooleanHistogram::BooleanHistogram(const string& name, 674 const BucketRanges* ranges) 675 : LinearHistogram(name, 1, 2, ranges) {} 676 677 HistogramBase* BooleanHistogram::DeserializeInfoImpl(PickleIterator* iter) { 678 string histogram_name; 679 int flags; 680 int declared_min; 681 int declared_max; 682 uint64 bucket_count; 683 uint32 range_checksum; 684 685 if (!ReadHistogramArguments(iter, &histogram_name, &flags, &declared_min, 686 &declared_max, &bucket_count, &range_checksum)) { 687 return NULL; 688 } 689 690 HistogramBase* histogram = BooleanHistogram::FactoryGet( 691 histogram_name, flags); 692 if (!ValidateRangeChecksum(*histogram, range_checksum)) { 693 // The serialized histogram might be corrupted. 694 return NULL; 695 } 696 return histogram; 697 } 698 699 //------------------------------------------------------------------------------ 700 // CustomHistogram: 701 //------------------------------------------------------------------------------ 702 703 HistogramBase* CustomHistogram::FactoryGet(const string& name, 704 const vector<Sample>& custom_ranges, 705 int32 flags) { 706 CHECK(ValidateCustomRanges(custom_ranges)); 707 708 HistogramBase* histogram = StatisticsRecorder::FindHistogram(name); 709 if (!histogram) { 710 BucketRanges* ranges = CreateBucketRangesFromCustomRanges(custom_ranges); 711 const BucketRanges* registered_ranges = 712 StatisticsRecorder::RegisterOrDeleteDuplicateRanges(ranges); 713 714 // To avoid racy destruction at shutdown, the following will be leaked. 715 CustomHistogram* tentative_histogram = 716 new CustomHistogram(name, registered_ranges); 717 718 tentative_histogram->SetFlags(flags); 719 720 histogram = 721 StatisticsRecorder::RegisterOrDeleteDuplicate(tentative_histogram); 722 } 723 724 DCHECK_EQ(histogram->GetHistogramType(), CUSTOM_HISTOGRAM); 725 return histogram; 726 } 727 728 HistogramType CustomHistogram::GetHistogramType() const { 729 return CUSTOM_HISTOGRAM; 730 } 731 732 // static 733 vector<Sample> CustomHistogram::ArrayToCustomRanges( 734 const Sample* values, size_t num_values) { 735 vector<Sample> all_values; 736 for (size_t i = 0; i < num_values; ++i) { 737 Sample value = values[i]; 738 all_values.push_back(value); 739 740 // Ensure that a guard bucket is added. If we end up with duplicate 741 // values, FactoryGet will take care of removing them. 742 all_values.push_back(value + 1); 743 } 744 return all_values; 745 } 746 747 CustomHistogram::CustomHistogram(const string& name, 748 const BucketRanges* ranges) 749 : Histogram(name, 750 ranges->range(1), 751 ranges->range(ranges->bucket_count() - 1), 752 ranges) {} 753 754 bool CustomHistogram::SerializeInfoImpl(Pickle* pickle) const { 755 if (!Histogram::SerializeInfoImpl(pickle)) 756 return false; 757 758 // Serialize ranges. First and last ranges are alwasy 0 and INT_MAX, so don't 759 // write them. 760 for (size_t i = 1; i < bucket_ranges()->bucket_count(); ++i) { 761 if (!pickle->WriteInt(bucket_ranges()->range(i))) 762 return false; 763 } 764 return true; 765 } 766 767 double CustomHistogram::GetBucketSize(Count current, size_t i) const { 768 return 1; 769 } 770 771 // static 772 HistogramBase* CustomHistogram::DeserializeInfoImpl(PickleIterator* iter) { 773 string histogram_name; 774 int flags; 775 int declared_min; 776 int declared_max; 777 uint64 bucket_count; 778 uint32 range_checksum; 779 780 if (!ReadHistogramArguments(iter, &histogram_name, &flags, &declared_min, 781 &declared_max, &bucket_count, &range_checksum)) { 782 return NULL; 783 } 784 785 // First and last ranges are not serialized. 786 vector<Sample> sample_ranges(bucket_count - 1); 787 788 for (size_t i = 0; i < sample_ranges.size(); ++i) { 789 if (!iter->ReadInt(&sample_ranges[i])) 790 return NULL; 791 } 792 793 HistogramBase* histogram = CustomHistogram::FactoryGet( 794 histogram_name, sample_ranges, flags); 795 if (!ValidateRangeChecksum(*histogram, range_checksum)) { 796 // The serialized histogram might be corrupted. 797 return NULL; 798 } 799 return histogram; 800 } 801 802 // static 803 bool CustomHistogram::ValidateCustomRanges( 804 const vector<Sample>& custom_ranges) { 805 bool has_valid_range = false; 806 for (size_t i = 0; i < custom_ranges.size(); i++) { 807 Sample sample = custom_ranges[i]; 808 if (sample < 0 || sample > HistogramBase::kSampleType_MAX - 1) 809 return false; 810 if (sample != 0) 811 has_valid_range = true; 812 } 813 return has_valid_range; 814 } 815 816 // static 817 BucketRanges* CustomHistogram::CreateBucketRangesFromCustomRanges( 818 const vector<Sample>& custom_ranges) { 819 // Remove the duplicates in the custom ranges array. 820 vector<int> ranges = custom_ranges; 821 ranges.push_back(0); // Ensure we have a zero value. 822 ranges.push_back(HistogramBase::kSampleType_MAX); 823 std::sort(ranges.begin(), ranges.end()); 824 ranges.erase(std::unique(ranges.begin(), ranges.end()), ranges.end()); 825 826 BucketRanges* bucket_ranges = new BucketRanges(ranges.size()); 827 for (size_t i = 0; i < ranges.size(); i++) { 828 bucket_ranges->set_range(i, ranges[i]); 829 } 830 bucket_ranges->ResetChecksum(); 831 return bucket_ranges; 832 } 833 834 } // namespace base 835