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 <inttypes.h> 13 #include <limits.h> 14 #include <math.h> 15 16 #include <algorithm> 17 #include <string> 18 #include <utility> 19 20 #include "base/compiler_specific.h" 21 #include "base/debug/alias.h" 22 #include "base/logging.h" 23 #include "base/memory/ptr_util.h" 24 #include "base/metrics/dummy_histogram.h" 25 #include "base/metrics/histogram_functions.h" 26 #include "base/metrics/metrics_hashes.h" 27 #include "base/metrics/persistent_histogram_allocator.h" 28 #include "base/metrics/persistent_memory_allocator.h" 29 #include "base/metrics/sample_vector.h" 30 #include "base/metrics/statistics_recorder.h" 31 #include "base/pickle.h" 32 #include "base/strings/string_util.h" 33 #include "base/strings/stringprintf.h" 34 #include "base/synchronization/lock.h" 35 #include "base/values.h" 36 #include "build/build_config.h" 37 38 namespace base { 39 40 namespace { 41 42 bool ReadHistogramArguments(PickleIterator* iter, 43 std::string* histogram_name, 44 int* flags, 45 int* declared_min, 46 int* declared_max, 47 uint32_t* bucket_count, 48 uint32_t* range_checksum) { 49 if (!iter->ReadString(histogram_name) || 50 !iter->ReadInt(flags) || 51 !iter->ReadInt(declared_min) || 52 !iter->ReadInt(declared_max) || 53 !iter->ReadUInt32(bucket_count) || 54 !iter->ReadUInt32(range_checksum)) { 55 DLOG(ERROR) << "Pickle error decoding Histogram: " << *histogram_name; 56 return false; 57 } 58 59 // Since these fields may have come from an untrusted renderer, do additional 60 // checks above and beyond those in Histogram::Initialize() 61 if (*declared_max <= 0 || 62 *declared_min <= 0 || 63 *declared_max < *declared_min || 64 INT_MAX / sizeof(HistogramBase::Count) <= *bucket_count || 65 *bucket_count < 2) { 66 DLOG(ERROR) << "Values error decoding Histogram: " << histogram_name; 67 return false; 68 } 69 70 // We use the arguments to find or create the local version of the histogram 71 // in this process, so we need to clear any IPC flag. 72 *flags &= ~HistogramBase::kIPCSerializationSourceFlag; 73 74 return true; 75 } 76 77 bool ValidateRangeChecksum(const HistogramBase& histogram, 78 uint32_t range_checksum) { 79 // Normally, |histogram| should have type HISTOGRAM or be inherited from it. 80 // However, if it's expired, it will actually be a DUMMY_HISTOGRAM. 81 // Skip the checks in that case. 82 if (histogram.GetHistogramType() == DUMMY_HISTOGRAM) 83 return true; 84 const Histogram& casted_histogram = 85 static_cast<const Histogram&>(histogram); 86 87 return casted_histogram.bucket_ranges()->checksum() == range_checksum; 88 } 89 90 } // namespace 91 92 typedef HistogramBase::Count Count; 93 typedef HistogramBase::Sample Sample; 94 95 // static 96 const uint32_t Histogram::kBucketCount_MAX = 16384u; 97 98 class Histogram::Factory { 99 public: 100 Factory(const std::string& name, 101 HistogramBase::Sample minimum, 102 HistogramBase::Sample maximum, 103 uint32_t bucket_count, 104 int32_t flags) 105 : Factory(name, HISTOGRAM, minimum, maximum, bucket_count, flags) {} 106 virtual ~Factory() = default; 107 108 // Create histogram based on construction parameters. Caller takes 109 // ownership of the returned object. 110 HistogramBase* Build(); 111 112 protected: 113 Factory(const std::string& name, 114 HistogramType histogram_type, 115 HistogramBase::Sample minimum, 116 HistogramBase::Sample maximum, 117 uint32_t bucket_count, 118 int32_t flags) 119 : name_(name), 120 histogram_type_(histogram_type), 121 minimum_(minimum), 122 maximum_(maximum), 123 bucket_count_(bucket_count), 124 flags_(flags) {} 125 126 // Create a BucketRanges structure appropriate for this histogram. 127 virtual BucketRanges* CreateRanges() { 128 BucketRanges* ranges = new BucketRanges(bucket_count_ + 1); 129 Histogram::InitializeBucketRanges(minimum_, maximum_, ranges); 130 return ranges; 131 } 132 133 // Allocate the correct Histogram object off the heap (in case persistent 134 // memory is not available). 135 virtual std::unique_ptr<HistogramBase> HeapAlloc(const BucketRanges* ranges) { 136 return WrapUnique( 137 new Histogram(GetPermanentName(name_), minimum_, maximum_, ranges)); 138 } 139 140 // Perform any required datafill on the just-created histogram. If 141 // overridden, be sure to call the "super" version -- this method may not 142 // always remain empty. 143 virtual void FillHistogram(HistogramBase* histogram) {} 144 145 // These values are protected (instead of private) because they need to 146 // be accessible to methods of sub-classes in order to avoid passing 147 // unnecessary parameters everywhere. 148 const std::string& name_; 149 const HistogramType histogram_type_; 150 HistogramBase::Sample minimum_; 151 HistogramBase::Sample maximum_; 152 uint32_t bucket_count_; 153 int32_t flags_; 154 155 private: 156 DISALLOW_COPY_AND_ASSIGN(Factory); 157 }; 158 159 HistogramBase* Histogram::Factory::Build() { 160 HistogramBase* histogram = StatisticsRecorder::FindHistogram(name_); 161 if (!histogram) { 162 // TODO(gayane): |HashMetricName()| is called again in Histogram 163 // constructor. Refactor code to avoid the additional call. 164 bool should_record = 165 StatisticsRecorder::ShouldRecordHistogram(HashMetricName(name_)); 166 if (!should_record) 167 return DummyHistogram::GetInstance(); 168 // To avoid racy destruction at shutdown, the following will be leaked. 169 const BucketRanges* created_ranges = CreateRanges(); 170 const BucketRanges* registered_ranges = 171 StatisticsRecorder::RegisterOrDeleteDuplicateRanges(created_ranges); 172 173 // In most cases, the bucket-count, minimum, and maximum values are known 174 // when the code is written and so are passed in explicitly. In other 175 // cases (such as with a CustomHistogram), they are calculated dynamically 176 // at run-time. In the latter case, those ctor parameters are zero and 177 // the results extracted from the result of CreateRanges(). 178 if (bucket_count_ == 0) { 179 bucket_count_ = static_cast<uint32_t>(registered_ranges->bucket_count()); 180 minimum_ = registered_ranges->range(1); 181 maximum_ = registered_ranges->range(bucket_count_ - 1); 182 } 183 DCHECK_EQ(minimum_, registered_ranges->range(1)); 184 DCHECK_EQ(maximum_, registered_ranges->range(bucket_count_ - 1)); 185 186 // Try to create the histogram using a "persistent" allocator. As of 187 // 2016-02-25, the availability of such is controlled by a base::Feature 188 // that is off by default. If the allocator doesn't exist or if 189 // allocating from it fails, code below will allocate the histogram from 190 // the process heap. 191 PersistentHistogramAllocator::Reference histogram_ref = 0; 192 std::unique_ptr<HistogramBase> tentative_histogram; 193 PersistentHistogramAllocator* allocator = GlobalHistogramAllocator::Get(); 194 if (allocator) { 195 tentative_histogram = allocator->AllocateHistogram( 196 histogram_type_, 197 name_, 198 minimum_, 199 maximum_, 200 registered_ranges, 201 flags_, 202 &histogram_ref); 203 } 204 205 // Handle the case where no persistent allocator is present or the 206 // persistent allocation fails (perhaps because it is full). 207 if (!tentative_histogram) { 208 DCHECK(!histogram_ref); // Should never have been set. 209 DCHECK(!allocator); // Shouldn't have failed. 210 flags_ &= ~HistogramBase::kIsPersistent; 211 tentative_histogram = HeapAlloc(registered_ranges); 212 tentative_histogram->SetFlags(flags_); 213 } 214 215 FillHistogram(tentative_histogram.get()); 216 217 // Register this histogram with the StatisticsRecorder. Keep a copy of 218 // the pointer value to tell later whether the locally created histogram 219 // was registered or deleted. The type is "void" because it could point 220 // to released memory after the following line. 221 const void* tentative_histogram_ptr = tentative_histogram.get(); 222 histogram = StatisticsRecorder::RegisterOrDeleteDuplicate( 223 tentative_histogram.release()); 224 225 // Persistent histograms need some follow-up processing. 226 if (histogram_ref) { 227 allocator->FinalizeHistogram(histogram_ref, 228 histogram == tentative_histogram_ptr); 229 } 230 } 231 232 if (histogram_type_ != histogram->GetHistogramType() || 233 (bucket_count_ != 0 && !histogram->HasConstructionArguments( 234 minimum_, maximum_, bucket_count_))) { 235 // The construction arguments do not match the existing histogram. This can 236 // come about if an extension updates in the middle of a chrome run and has 237 // changed one of them, or simply by bad code within Chrome itself. A NULL 238 // return would cause Chrome to crash; better to just record it for later 239 // analysis. 240 UmaHistogramSparse("Histogram.MismatchedConstructionArguments", 241 static_cast<Sample>(HashMetricName(name_))); 242 DLOG(ERROR) << "Histogram " << name_ 243 << " has mismatched construction arguments"; 244 return DummyHistogram::GetInstance(); 245 } 246 return histogram; 247 } 248 249 HistogramBase* Histogram::FactoryGet(const std::string& name, 250 Sample minimum, 251 Sample maximum, 252 uint32_t bucket_count, 253 int32_t flags) { 254 bool valid_arguments = 255 InspectConstructionArguments(name, &minimum, &maximum, &bucket_count); 256 DCHECK(valid_arguments); 257 258 return Factory(name, minimum, maximum, bucket_count, flags).Build(); 259 } 260 261 HistogramBase* Histogram::FactoryTimeGet(const std::string& name, 262 TimeDelta minimum, 263 TimeDelta maximum, 264 uint32_t bucket_count, 265 int32_t flags) { 266 return FactoryGet(name, static_cast<Sample>(minimum.InMilliseconds()), 267 static_cast<Sample>(maximum.InMilliseconds()), bucket_count, 268 flags); 269 } 270 271 HistogramBase* Histogram::FactoryMicrosecondsTimeGet(const std::string& name, 272 TimeDelta minimum, 273 TimeDelta maximum, 274 uint32_t bucket_count, 275 int32_t flags) { 276 return FactoryGet(name, static_cast<Sample>(minimum.InMicroseconds()), 277 static_cast<Sample>(maximum.InMicroseconds()), bucket_count, 278 flags); 279 } 280 281 HistogramBase* Histogram::FactoryGet(const char* name, 282 Sample minimum, 283 Sample maximum, 284 uint32_t bucket_count, 285 int32_t flags) { 286 return FactoryGet(std::string(name), minimum, maximum, bucket_count, flags); 287 } 288 289 HistogramBase* Histogram::FactoryTimeGet(const char* name, 290 TimeDelta minimum, 291 TimeDelta maximum, 292 uint32_t bucket_count, 293 int32_t flags) { 294 return FactoryTimeGet(std::string(name), minimum, maximum, bucket_count, 295 flags); 296 } 297 298 HistogramBase* Histogram::FactoryMicrosecondsTimeGet(const char* name, 299 TimeDelta minimum, 300 TimeDelta maximum, 301 uint32_t bucket_count, 302 int32_t flags) { 303 return FactoryMicrosecondsTimeGet(std::string(name), minimum, maximum, 304 bucket_count, flags); 305 } 306 307 std::unique_ptr<HistogramBase> Histogram::PersistentCreate( 308 const char* name, 309 Sample minimum, 310 Sample maximum, 311 const BucketRanges* ranges, 312 const DelayedPersistentAllocation& counts, 313 const DelayedPersistentAllocation& logged_counts, 314 HistogramSamples::Metadata* meta, 315 HistogramSamples::Metadata* logged_meta) { 316 return WrapUnique(new Histogram(name, minimum, maximum, ranges, counts, 317 logged_counts, meta, logged_meta)); 318 } 319 320 // Calculate what range of values are held in each bucket. 321 // We have to be careful that we don't pick a ratio between starting points in 322 // consecutive buckets that is sooo small, that the integer bounds are the same 323 // (effectively making one bucket get no values). We need to avoid: 324 // ranges(i) == ranges(i + 1) 325 // To avoid that, we just do a fine-grained bucket width as far as we need to 326 // until we get a ratio that moves us along at least 2 units at a time. From 327 // that bucket onward we do use the exponential growth of buckets. 328 // 329 // static 330 void Histogram::InitializeBucketRanges(Sample minimum, 331 Sample maximum, 332 BucketRanges* ranges) { 333 double log_max = log(static_cast<double>(maximum)); 334 double log_ratio; 335 double log_next; 336 size_t bucket_index = 1; 337 Sample current = minimum; 338 ranges->set_range(bucket_index, current); 339 size_t bucket_count = ranges->bucket_count(); 340 while (bucket_count > ++bucket_index) { 341 double log_current; 342 log_current = log(static_cast<double>(current)); 343 // Calculate the count'th root of the range. 344 log_ratio = (log_max - log_current) / (bucket_count - bucket_index); 345 // See where the next bucket would start. 346 log_next = log_current + log_ratio; 347 Sample next; 348 next = static_cast<int>(std::round(exp(log_next))); 349 if (next > current) 350 current = next; 351 else 352 ++current; // Just do a narrow bucket, and keep trying. 353 ranges->set_range(bucket_index, current); 354 } 355 ranges->set_range(ranges->bucket_count(), HistogramBase::kSampleType_MAX); 356 ranges->ResetChecksum(); 357 } 358 359 // static 360 const int Histogram::kCommonRaceBasedCountMismatch = 5; 361 362 uint32_t Histogram::FindCorruption(const HistogramSamples& samples) const { 363 int inconsistencies = NO_INCONSISTENCIES; 364 Sample previous_range = -1; // Bottom range is always 0. 365 for (uint32_t index = 0; index < bucket_count(); ++index) { 366 int new_range = ranges(index); 367 if (previous_range >= new_range) 368 inconsistencies |= BUCKET_ORDER_ERROR; 369 previous_range = new_range; 370 } 371 372 if (!bucket_ranges()->HasValidChecksum()) 373 inconsistencies |= RANGE_CHECKSUM_ERROR; 374 375 int64_t delta64 = samples.redundant_count() - samples.TotalCount(); 376 if (delta64 != 0) { 377 int delta = static_cast<int>(delta64); 378 if (delta != delta64) 379 delta = INT_MAX; // Flag all giant errors as INT_MAX. 380 if (delta > 0) { 381 if (delta > kCommonRaceBasedCountMismatch) 382 inconsistencies |= COUNT_HIGH_ERROR; 383 } else { 384 DCHECK_GT(0, delta); 385 if (-delta > kCommonRaceBasedCountMismatch) 386 inconsistencies |= COUNT_LOW_ERROR; 387 } 388 } 389 return inconsistencies; 390 } 391 392 const BucketRanges* Histogram::bucket_ranges() const { 393 return unlogged_samples_->bucket_ranges(); 394 } 395 396 Sample Histogram::declared_min() const { 397 const BucketRanges* ranges = bucket_ranges(); 398 if (ranges->bucket_count() < 2) 399 return -1; 400 return ranges->range(1); 401 } 402 403 Sample Histogram::declared_max() const { 404 const BucketRanges* ranges = bucket_ranges(); 405 if (ranges->bucket_count() < 2) 406 return -1; 407 return ranges->range(ranges->bucket_count() - 1); 408 } 409 410 Sample Histogram::ranges(uint32_t i) const { 411 return bucket_ranges()->range(i); 412 } 413 414 uint32_t Histogram::bucket_count() const { 415 return static_cast<uint32_t>(bucket_ranges()->bucket_count()); 416 } 417 418 // static 419 bool Histogram::InspectConstructionArguments(StringPiece name, 420 Sample* minimum, 421 Sample* maximum, 422 uint32_t* bucket_count) { 423 // Defensive code for backward compatibility. 424 if (*minimum < 1) { 425 DVLOG(1) << "Histogram: " << name << " has bad minimum: " << *minimum; 426 *minimum = 1; 427 } 428 if (*maximum >= kSampleType_MAX) { 429 DVLOG(1) << "Histogram: " << name << " has bad maximum: " << *maximum; 430 *maximum = kSampleType_MAX - 1; 431 } 432 if (*bucket_count >= kBucketCount_MAX) { 433 DVLOG(1) << "Histogram: " << name << " has bad bucket_count: " 434 << *bucket_count; 435 *bucket_count = kBucketCount_MAX - 1; 436 } 437 438 bool check_okay = true; 439 440 if (*minimum > *maximum) { 441 check_okay = false; 442 std::swap(*minimum, *maximum); 443 } 444 if (*maximum == *minimum) { 445 check_okay = false; 446 *maximum = *minimum + 1; 447 } 448 if (*bucket_count < 3) { 449 check_okay = false; 450 *bucket_count = 3; 451 } 452 // Very high bucket counts are wasteful. Use a sparse histogram instead. 453 // Value of 10002 equals a user-supplied value of 10k + 2 overflow buckets. 454 constexpr uint32_t kMaxBucketCount = 10002; 455 if (*bucket_count > kMaxBucketCount) { 456 check_okay = false; 457 *bucket_count = kMaxBucketCount; 458 } 459 if (*bucket_count > static_cast<uint32_t>(*maximum - *minimum + 2)) { 460 check_okay = false; 461 *bucket_count = static_cast<uint32_t>(*maximum - *minimum + 2); 462 } 463 464 if (!check_okay) { 465 UmaHistogramSparse("Histogram.BadConstructionArguments", 466 static_cast<Sample>(HashMetricName(name))); 467 } 468 469 return check_okay; 470 } 471 472 uint64_t Histogram::name_hash() const { 473 return unlogged_samples_->id(); 474 } 475 476 HistogramType Histogram::GetHistogramType() const { 477 return HISTOGRAM; 478 } 479 480 bool Histogram::HasConstructionArguments(Sample expected_minimum, 481 Sample expected_maximum, 482 uint32_t expected_bucket_count) const { 483 return (expected_bucket_count == bucket_count() && 484 expected_minimum == declared_min() && 485 expected_maximum == declared_max()); 486 } 487 488 void Histogram::Add(int value) { 489 AddCount(value, 1); 490 } 491 492 void Histogram::AddCount(int value, int count) { 493 DCHECK_EQ(0, ranges(0)); 494 DCHECK_EQ(kSampleType_MAX, ranges(bucket_count())); 495 496 if (value > kSampleType_MAX - 1) 497 value = kSampleType_MAX - 1; 498 if (value < 0) 499 value = 0; 500 if (count <= 0) { 501 NOTREACHED(); 502 return; 503 } 504 unlogged_samples_->Accumulate(value, count); 505 506 FindAndRunCallback(value); 507 } 508 509 std::unique_ptr<HistogramSamples> Histogram::SnapshotSamples() const { 510 return SnapshotAllSamples(); 511 } 512 513 std::unique_ptr<HistogramSamples> Histogram::SnapshotDelta() { 514 #if DCHECK_IS_ON() 515 DCHECK(!final_delta_created_); 516 #endif 517 518 // The code below has subtle thread-safety guarantees! All changes to 519 // the underlying SampleVectors use atomic integer operations, which guarantee 520 // eventual consistency, but do not guarantee full synchronization between 521 // different entries in the SampleVector. In particular, this means that 522 // concurrent updates to the histogram might result in the reported sum not 523 // matching the individual bucket counts; or there being some buckets that are 524 // logically updated "together", but end up being only partially updated when 525 // a snapshot is captured. Note that this is why it's important to subtract 526 // exactly the snapshotted unlogged samples, rather than simply resetting the 527 // vector: this way, the next snapshot will include any concurrent updates 528 // missed by the current snapshot. 529 530 std::unique_ptr<HistogramSamples> snapshot = SnapshotUnloggedSamples(); 531 unlogged_samples_->Subtract(*snapshot); 532 logged_samples_->Add(*snapshot); 533 534 return snapshot; 535 } 536 537 std::unique_ptr<HistogramSamples> Histogram::SnapshotFinalDelta() const { 538 #if DCHECK_IS_ON() 539 DCHECK(!final_delta_created_); 540 final_delta_created_ = true; 541 #endif 542 543 return SnapshotUnloggedSamples(); 544 } 545 546 void Histogram::AddSamples(const HistogramSamples& samples) { 547 unlogged_samples_->Add(samples); 548 } 549 550 bool Histogram::AddSamplesFromPickle(PickleIterator* iter) { 551 return unlogged_samples_->AddFromPickle(iter); 552 } 553 554 // The following methods provide a graphical histogram display. 555 void Histogram::WriteHTMLGraph(std::string* output) const { 556 // TBD(jar) Write a nice HTML bar chart, with divs an mouse-overs etc. 557 output->append("<PRE>"); 558 WriteAsciiImpl(true, "<br>", output); 559 output->append("</PRE>"); 560 } 561 562 void Histogram::WriteAscii(std::string* output) const { 563 WriteAsciiImpl(true, "\n", output); 564 } 565 566 void Histogram::ValidateHistogramContents() const { 567 CHECK(unlogged_samples_); 568 CHECK(unlogged_samples_->bucket_ranges()); 569 CHECK(logged_samples_); 570 CHECK(logged_samples_->bucket_ranges()); 571 CHECK_NE(0U, logged_samples_->id()); 572 } 573 574 void Histogram::SerializeInfoImpl(Pickle* pickle) const { 575 DCHECK(bucket_ranges()->HasValidChecksum()); 576 pickle->WriteString(histogram_name()); 577 pickle->WriteInt(flags()); 578 pickle->WriteInt(declared_min()); 579 pickle->WriteInt(declared_max()); 580 pickle->WriteUInt32(bucket_count()); 581 pickle->WriteUInt32(bucket_ranges()->checksum()); 582 } 583 584 // TODO(bcwhite): Remove minimum/maximum parameters from here and call chain. 585 Histogram::Histogram(const char* name, 586 Sample minimum, 587 Sample maximum, 588 const BucketRanges* ranges) 589 : HistogramBase(name) { 590 DCHECK(ranges) << name << ": " << minimum << "-" << maximum; 591 unlogged_samples_.reset(new SampleVector(HashMetricName(name), ranges)); 592 logged_samples_.reset(new SampleVector(unlogged_samples_->id(), ranges)); 593 } 594 595 Histogram::Histogram(const char* name, 596 Sample minimum, 597 Sample maximum, 598 const BucketRanges* ranges, 599 const DelayedPersistentAllocation& counts, 600 const DelayedPersistentAllocation& logged_counts, 601 HistogramSamples::Metadata* meta, 602 HistogramSamples::Metadata* logged_meta) 603 : HistogramBase(name) { 604 DCHECK(ranges) << name << ": " << minimum << "-" << maximum; 605 unlogged_samples_.reset( 606 new PersistentSampleVector(HashMetricName(name), ranges, meta, counts)); 607 logged_samples_.reset(new PersistentSampleVector( 608 unlogged_samples_->id(), ranges, logged_meta, logged_counts)); 609 } 610 611 Histogram::~Histogram() = default; 612 613 bool Histogram::PrintEmptyBucket(uint32_t index) const { 614 return true; 615 } 616 617 // Use the actual bucket widths (like a linear histogram) until the widths get 618 // over some transition value, and then use that transition width. Exponentials 619 // get so big so fast (and we don't expect to see a lot of entries in the large 620 // buckets), so we need this to make it possible to see what is going on and 621 // not have 0-graphical-height buckets. 622 double Histogram::GetBucketSize(Count current, uint32_t i) const { 623 DCHECK_GT(ranges(i + 1), ranges(i)); 624 static const double kTransitionWidth = 5; 625 double denominator = ranges(i + 1) - ranges(i); 626 if (denominator > kTransitionWidth) 627 denominator = kTransitionWidth; // Stop trying to normalize. 628 return current/denominator; 629 } 630 631 const std::string Histogram::GetAsciiBucketRange(uint32_t i) const { 632 return GetSimpleAsciiBucketRange(ranges(i)); 633 } 634 635 //------------------------------------------------------------------------------ 636 // Private methods 637 638 // static 639 HistogramBase* Histogram::DeserializeInfoImpl(PickleIterator* iter) { 640 std::string histogram_name; 641 int flags; 642 int declared_min; 643 int declared_max; 644 uint32_t bucket_count; 645 uint32_t range_checksum; 646 647 if (!ReadHistogramArguments(iter, &histogram_name, &flags, &declared_min, 648 &declared_max, &bucket_count, &range_checksum)) { 649 return nullptr; 650 } 651 652 // Find or create the local version of the histogram in this process. 653 HistogramBase* histogram = Histogram::FactoryGet( 654 histogram_name, declared_min, declared_max, bucket_count, flags); 655 if (!histogram) 656 return nullptr; 657 658 // The serialized histogram might be corrupted. 659 if (!ValidateRangeChecksum(*histogram, range_checksum)) 660 return nullptr; 661 662 return histogram; 663 } 664 665 std::unique_ptr<SampleVector> Histogram::SnapshotAllSamples() const { 666 std::unique_ptr<SampleVector> samples = SnapshotUnloggedSamples(); 667 samples->Add(*logged_samples_); 668 return samples; 669 } 670 671 std::unique_ptr<SampleVector> Histogram::SnapshotUnloggedSamples() const { 672 std::unique_ptr<SampleVector> samples( 673 new SampleVector(unlogged_samples_->id(), bucket_ranges())); 674 samples->Add(*unlogged_samples_); 675 return samples; 676 } 677 678 void Histogram::WriteAsciiImpl(bool graph_it, 679 const std::string& newline, 680 std::string* output) const { 681 // Get local (stack) copies of all effectively volatile class data so that we 682 // are consistent across our output activities. 683 std::unique_ptr<SampleVector> snapshot = SnapshotAllSamples(); 684 Count sample_count = snapshot->TotalCount(); 685 686 WriteAsciiHeader(*snapshot, sample_count, output); 687 output->append(newline); 688 689 // Prepare to normalize graphical rendering of bucket contents. 690 double max_size = 0; 691 if (graph_it) 692 max_size = GetPeakBucketSize(*snapshot); 693 694 // Calculate space needed to print bucket range numbers. Leave room to print 695 // nearly the largest bucket range without sliding over the histogram. 696 uint32_t largest_non_empty_bucket = bucket_count() - 1; 697 while (0 == snapshot->GetCountAtIndex(largest_non_empty_bucket)) { 698 if (0 == largest_non_empty_bucket) 699 break; // All buckets are empty. 700 --largest_non_empty_bucket; 701 } 702 703 // Calculate largest print width needed for any of our bucket range displays. 704 size_t print_width = 1; 705 for (uint32_t i = 0; i < bucket_count(); ++i) { 706 if (snapshot->GetCountAtIndex(i)) { 707 size_t width = GetAsciiBucketRange(i).size() + 1; 708 if (width > print_width) 709 print_width = width; 710 } 711 } 712 713 int64_t remaining = sample_count; 714 int64_t past = 0; 715 // Output the actual histogram graph. 716 for (uint32_t i = 0; i < bucket_count(); ++i) { 717 Count current = snapshot->GetCountAtIndex(i); 718 if (!current && !PrintEmptyBucket(i)) 719 continue; 720 remaining -= current; 721 std::string range = GetAsciiBucketRange(i); 722 output->append(range); 723 for (size_t j = 0; range.size() + j < print_width + 1; ++j) 724 output->push_back(' '); 725 if (0 == current && i < bucket_count() - 1 && 726 0 == snapshot->GetCountAtIndex(i + 1)) { 727 while (i < bucket_count() - 1 && 728 0 == snapshot->GetCountAtIndex(i + 1)) { 729 ++i; 730 } 731 output->append("... "); 732 output->append(newline); 733 continue; // No reason to plot emptiness. 734 } 735 double current_size = GetBucketSize(current, i); 736 if (graph_it) 737 WriteAsciiBucketGraph(current_size, max_size, output); 738 WriteAsciiBucketContext(past, current, remaining, i, output); 739 output->append(newline); 740 past += current; 741 } 742 DCHECK_EQ(sample_count, past); 743 } 744 745 double Histogram::GetPeakBucketSize(const SampleVectorBase& samples) const { 746 double max = 0; 747 for (uint32_t i = 0; i < bucket_count() ; ++i) { 748 double current_size = GetBucketSize(samples.GetCountAtIndex(i), i); 749 if (current_size > max) 750 max = current_size; 751 } 752 return max; 753 } 754 755 void Histogram::WriteAsciiHeader(const SampleVectorBase& samples, 756 Count sample_count, 757 std::string* output) const { 758 StringAppendF(output, "Histogram: %s recorded %d samples", histogram_name(), 759 sample_count); 760 if (sample_count == 0) { 761 DCHECK_EQ(samples.sum(), 0); 762 } else { 763 double mean = static_cast<float>(samples.sum()) / sample_count; 764 StringAppendF(output, ", mean = %.1f", mean); 765 } 766 if (flags()) 767 StringAppendF(output, " (flags = 0x%x)", flags()); 768 } 769 770 void Histogram::WriteAsciiBucketContext(const int64_t past, 771 const Count current, 772 const int64_t remaining, 773 const uint32_t i, 774 std::string* output) const { 775 double scaled_sum = (past + current + remaining) / 100.0; 776 WriteAsciiBucketValue(current, scaled_sum, output); 777 if (0 < i) { 778 double percentage = past / scaled_sum; 779 StringAppendF(output, " {%3.1f%%}", percentage); 780 } 781 } 782 783 void Histogram::GetParameters(DictionaryValue* params) const { 784 params->SetString("type", HistogramTypeToString(GetHistogramType())); 785 params->SetInteger("min", declared_min()); 786 params->SetInteger("max", declared_max()); 787 params->SetInteger("bucket_count", static_cast<int>(bucket_count())); 788 } 789 790 void Histogram::GetCountAndBucketData(Count* count, 791 int64_t* sum, 792 ListValue* buckets) const { 793 std::unique_ptr<SampleVector> snapshot = SnapshotAllSamples(); 794 *count = snapshot->TotalCount(); 795 *sum = snapshot->sum(); 796 uint32_t index = 0; 797 for (uint32_t i = 0; i < bucket_count(); ++i) { 798 Sample count_at_index = snapshot->GetCountAtIndex(i); 799 if (count_at_index > 0) { 800 std::unique_ptr<DictionaryValue> bucket_value(new DictionaryValue()); 801 bucket_value->SetInteger("low", ranges(i)); 802 if (i != bucket_count() - 1) 803 bucket_value->SetInteger("high", ranges(i + 1)); 804 bucket_value->SetInteger("count", count_at_index); 805 buckets->Set(index, std::move(bucket_value)); 806 ++index; 807 } 808 } 809 } 810 811 //------------------------------------------------------------------------------ 812 // LinearHistogram: This histogram uses a traditional set of evenly spaced 813 // buckets. 814 //------------------------------------------------------------------------------ 815 816 class LinearHistogram::Factory : public Histogram::Factory { 817 public: 818 Factory(const std::string& name, 819 HistogramBase::Sample minimum, 820 HistogramBase::Sample maximum, 821 uint32_t bucket_count, 822 int32_t flags, 823 const DescriptionPair* descriptions) 824 : Histogram::Factory(name, LINEAR_HISTOGRAM, minimum, maximum, 825 bucket_count, flags) { 826 descriptions_ = descriptions; 827 } 828 ~Factory() override = default; 829 830 protected: 831 BucketRanges* CreateRanges() override { 832 BucketRanges* ranges = new BucketRanges(bucket_count_ + 1); 833 LinearHistogram::InitializeBucketRanges(minimum_, maximum_, ranges); 834 return ranges; 835 } 836 837 std::unique_ptr<HistogramBase> HeapAlloc( 838 const BucketRanges* ranges) override { 839 return WrapUnique(new LinearHistogram(GetPermanentName(name_), minimum_, 840 maximum_, ranges)); 841 } 842 843 void FillHistogram(HistogramBase* base_histogram) override { 844 Histogram::Factory::FillHistogram(base_histogram); 845 // Normally, |base_histogram| should have type LINEAR_HISTOGRAM or be 846 // inherited from it. However, if it's expired, it will actually be a 847 // DUMMY_HISTOGRAM. Skip filling in that case. 848 if (base_histogram->GetHistogramType() == DUMMY_HISTOGRAM) 849 return; 850 LinearHistogram* histogram = static_cast<LinearHistogram*>(base_histogram); 851 // Set range descriptions. 852 if (descriptions_) { 853 for (int i = 0; descriptions_[i].description; ++i) { 854 histogram->bucket_description_[descriptions_[i].sample] = 855 descriptions_[i].description; 856 } 857 } 858 } 859 860 private: 861 const DescriptionPair* descriptions_; 862 863 DISALLOW_COPY_AND_ASSIGN(Factory); 864 }; 865 866 LinearHistogram::~LinearHistogram() = default; 867 868 HistogramBase* LinearHistogram::FactoryGet(const std::string& name, 869 Sample minimum, 870 Sample maximum, 871 uint32_t bucket_count, 872 int32_t flags) { 873 return FactoryGetWithRangeDescription(name, minimum, maximum, bucket_count, 874 flags, NULL); 875 } 876 877 HistogramBase* LinearHistogram::FactoryTimeGet(const std::string& name, 878 TimeDelta minimum, 879 TimeDelta maximum, 880 uint32_t bucket_count, 881 int32_t flags) { 882 return FactoryGet(name, static_cast<Sample>(minimum.InMilliseconds()), 883 static_cast<Sample>(maximum.InMilliseconds()), bucket_count, 884 flags); 885 } 886 887 HistogramBase* LinearHistogram::FactoryGet(const char* name, 888 Sample minimum, 889 Sample maximum, 890 uint32_t bucket_count, 891 int32_t flags) { 892 return FactoryGet(std::string(name), minimum, maximum, bucket_count, flags); 893 } 894 895 HistogramBase* LinearHistogram::FactoryTimeGet(const char* name, 896 TimeDelta minimum, 897 TimeDelta maximum, 898 uint32_t bucket_count, 899 int32_t flags) { 900 return FactoryTimeGet(std::string(name), minimum, maximum, bucket_count, 901 flags); 902 } 903 904 std::unique_ptr<HistogramBase> LinearHistogram::PersistentCreate( 905 const char* name, 906 Sample minimum, 907 Sample maximum, 908 const BucketRanges* ranges, 909 const DelayedPersistentAllocation& counts, 910 const DelayedPersistentAllocation& logged_counts, 911 HistogramSamples::Metadata* meta, 912 HistogramSamples::Metadata* logged_meta) { 913 return WrapUnique(new LinearHistogram(name, minimum, maximum, ranges, counts, 914 logged_counts, meta, logged_meta)); 915 } 916 917 HistogramBase* LinearHistogram::FactoryGetWithRangeDescription( 918 const std::string& name, 919 Sample minimum, 920 Sample maximum, 921 uint32_t bucket_count, 922 int32_t flags, 923 const DescriptionPair descriptions[]) { 924 bool valid_arguments = Histogram::InspectConstructionArguments( 925 name, &minimum, &maximum, &bucket_count); 926 DCHECK(valid_arguments); 927 928 return Factory(name, minimum, maximum, bucket_count, flags, descriptions) 929 .Build(); 930 } 931 932 HistogramType LinearHistogram::GetHistogramType() const { 933 return LINEAR_HISTOGRAM; 934 } 935 936 LinearHistogram::LinearHistogram(const char* name, 937 Sample minimum, 938 Sample maximum, 939 const BucketRanges* ranges) 940 : Histogram(name, minimum, maximum, ranges) {} 941 942 LinearHistogram::LinearHistogram( 943 const char* name, 944 Sample minimum, 945 Sample maximum, 946 const BucketRanges* ranges, 947 const DelayedPersistentAllocation& counts, 948 const DelayedPersistentAllocation& logged_counts, 949 HistogramSamples::Metadata* meta, 950 HistogramSamples::Metadata* logged_meta) 951 : Histogram(name, 952 minimum, 953 maximum, 954 ranges, 955 counts, 956 logged_counts, 957 meta, 958 logged_meta) {} 959 960 double LinearHistogram::GetBucketSize(Count current, uint32_t i) const { 961 DCHECK_GT(ranges(i + 1), ranges(i)); 962 // Adjacent buckets with different widths would have "surprisingly" many (few) 963 // samples in a histogram if we didn't normalize this way. 964 double denominator = ranges(i + 1) - ranges(i); 965 return current/denominator; 966 } 967 968 const std::string LinearHistogram::GetAsciiBucketRange(uint32_t i) const { 969 int range = ranges(i); 970 BucketDescriptionMap::const_iterator it = bucket_description_.find(range); 971 if (it == bucket_description_.end()) 972 return Histogram::GetAsciiBucketRange(i); 973 return it->second; 974 } 975 976 bool LinearHistogram::PrintEmptyBucket(uint32_t index) const { 977 return bucket_description_.find(ranges(index)) == bucket_description_.end(); 978 } 979 980 // static 981 void LinearHistogram::InitializeBucketRanges(Sample minimum, 982 Sample maximum, 983 BucketRanges* ranges) { 984 double min = minimum; 985 double max = maximum; 986 size_t bucket_count = ranges->bucket_count(); 987 for (size_t i = 1; i < bucket_count; ++i) { 988 double linear_range = 989 (min * (bucket_count - 1 - i) + max * (i - 1)) / (bucket_count - 2); 990 ranges->set_range(i, static_cast<Sample>(linear_range + 0.5)); 991 } 992 ranges->set_range(ranges->bucket_count(), HistogramBase::kSampleType_MAX); 993 ranges->ResetChecksum(); 994 } 995 996 // static 997 HistogramBase* LinearHistogram::DeserializeInfoImpl(PickleIterator* iter) { 998 std::string histogram_name; 999 int flags; 1000 int declared_min; 1001 int declared_max; 1002 uint32_t bucket_count; 1003 uint32_t range_checksum; 1004 1005 if (!ReadHistogramArguments(iter, &histogram_name, &flags, &declared_min, 1006 &declared_max, &bucket_count, &range_checksum)) { 1007 return nullptr; 1008 } 1009 1010 HistogramBase* histogram = LinearHistogram::FactoryGet( 1011 histogram_name, declared_min, declared_max, bucket_count, flags); 1012 if (!histogram) 1013 return nullptr; 1014 1015 if (!ValidateRangeChecksum(*histogram, range_checksum)) { 1016 // The serialized histogram might be corrupted. 1017 return nullptr; 1018 } 1019 return histogram; 1020 } 1021 1022 //------------------------------------------------------------------------------ 1023 // ScaledLinearHistogram: This is a wrapper around a LinearHistogram that 1024 // scales input counts. 1025 //------------------------------------------------------------------------------ 1026 1027 ScaledLinearHistogram::ScaledLinearHistogram(const char* name, 1028 Sample minimum, 1029 Sample maximum, 1030 uint32_t bucket_count, 1031 int32_t scale, 1032 int32_t flags) 1033 : histogram_(static_cast<LinearHistogram*>( 1034 LinearHistogram::FactoryGet(name, 1035 minimum, 1036 maximum, 1037 bucket_count, 1038 flags))), 1039 scale_(scale) { 1040 DCHECK(histogram_); 1041 DCHECK_LT(1, scale); 1042 DCHECK_EQ(1, minimum); 1043 CHECK_EQ(static_cast<Sample>(bucket_count), maximum - minimum + 2) 1044 << " ScaledLinearHistogram requires buckets of size 1"; 1045 1046 remainders_.resize(histogram_->bucket_count(), 0); 1047 } 1048 1049 ScaledLinearHistogram::~ScaledLinearHistogram() = default; 1050 1051 void ScaledLinearHistogram::AddScaledCount(Sample value, int count) { 1052 if (count == 0) 1053 return; 1054 if (count < 0) { 1055 NOTREACHED(); 1056 return; 1057 } 1058 const int32_t max_value = 1059 static_cast<int32_t>(histogram_->bucket_count() - 1); 1060 if (value > max_value) 1061 value = max_value; 1062 if (value < 0) 1063 value = 0; 1064 1065 int scaled_count = count / scale_; 1066 subtle::Atomic32 remainder = count - scaled_count * scale_; 1067 1068 // ScaledLinearHistogram currently requires 1-to-1 mappings between value 1069 // and bucket which alleviates the need to do a bucket lookup here (something 1070 // that is internal to the HistogramSamples object). 1071 if (remainder > 0) { 1072 remainder = 1073 subtle::NoBarrier_AtomicIncrement(&remainders_[value], remainder); 1074 // If remainder passes 1/2 scale, increment main count (thus rounding up). 1075 // The remainder is decremented by the full scale, though, which will 1076 // cause it to go negative and thus requrire another increase by the full 1077 // scale amount before another bump of the scaled count. 1078 if (remainder >= scale_ / 2) { 1079 scaled_count += 1; 1080 subtle::NoBarrier_AtomicIncrement(&remainders_[value], -scale_); 1081 } 1082 } 1083 1084 if (scaled_count > 0) 1085 histogram_->AddCount(value, scaled_count); 1086 } 1087 1088 //------------------------------------------------------------------------------ 1089 // This section provides implementation for BooleanHistogram. 1090 //------------------------------------------------------------------------------ 1091 1092 class BooleanHistogram::Factory : public Histogram::Factory { 1093 public: 1094 Factory(const std::string& name, int32_t flags) 1095 : Histogram::Factory(name, BOOLEAN_HISTOGRAM, 1, 2, 3, flags) {} 1096 ~Factory() override = default; 1097 1098 protected: 1099 BucketRanges* CreateRanges() override { 1100 BucketRanges* ranges = new BucketRanges(3 + 1); 1101 LinearHistogram::InitializeBucketRanges(1, 2, ranges); 1102 return ranges; 1103 } 1104 1105 std::unique_ptr<HistogramBase> HeapAlloc( 1106 const BucketRanges* ranges) override { 1107 return WrapUnique(new BooleanHistogram(GetPermanentName(name_), ranges)); 1108 } 1109 1110 private: 1111 DISALLOW_COPY_AND_ASSIGN(Factory); 1112 }; 1113 1114 HistogramBase* BooleanHistogram::FactoryGet(const std::string& name, 1115 int32_t flags) { 1116 return Factory(name, flags).Build(); 1117 } 1118 1119 HistogramBase* BooleanHistogram::FactoryGet(const char* name, int32_t flags) { 1120 return FactoryGet(std::string(name), flags); 1121 } 1122 1123 std::unique_ptr<HistogramBase> BooleanHistogram::PersistentCreate( 1124 const char* name, 1125 const BucketRanges* ranges, 1126 const DelayedPersistentAllocation& counts, 1127 const DelayedPersistentAllocation& logged_counts, 1128 HistogramSamples::Metadata* meta, 1129 HistogramSamples::Metadata* logged_meta) { 1130 return WrapUnique(new BooleanHistogram(name, ranges, counts, logged_counts, 1131 meta, logged_meta)); 1132 } 1133 1134 HistogramType BooleanHistogram::GetHistogramType() const { 1135 return BOOLEAN_HISTOGRAM; 1136 } 1137 1138 BooleanHistogram::BooleanHistogram(const char* name, const BucketRanges* ranges) 1139 : LinearHistogram(name, 1, 2, ranges) {} 1140 1141 BooleanHistogram::BooleanHistogram( 1142 const char* name, 1143 const BucketRanges* ranges, 1144 const DelayedPersistentAllocation& counts, 1145 const DelayedPersistentAllocation& logged_counts, 1146 HistogramSamples::Metadata* meta, 1147 HistogramSamples::Metadata* logged_meta) 1148 : LinearHistogram(name, 1149 1, 1150 2, 1151 ranges, 1152 counts, 1153 logged_counts, 1154 meta, 1155 logged_meta) {} 1156 1157 HistogramBase* BooleanHistogram::DeserializeInfoImpl(PickleIterator* iter) { 1158 std::string histogram_name; 1159 int flags; 1160 int declared_min; 1161 int declared_max; 1162 uint32_t bucket_count; 1163 uint32_t range_checksum; 1164 1165 if (!ReadHistogramArguments(iter, &histogram_name, &flags, &declared_min, 1166 &declared_max, &bucket_count, &range_checksum)) { 1167 return nullptr; 1168 } 1169 1170 HistogramBase* histogram = BooleanHistogram::FactoryGet( 1171 histogram_name, flags); 1172 if (!histogram) 1173 return nullptr; 1174 1175 if (!ValidateRangeChecksum(*histogram, range_checksum)) { 1176 // The serialized histogram might be corrupted. 1177 return nullptr; 1178 } 1179 return histogram; 1180 } 1181 1182 //------------------------------------------------------------------------------ 1183 // CustomHistogram: 1184 //------------------------------------------------------------------------------ 1185 1186 class CustomHistogram::Factory : public Histogram::Factory { 1187 public: 1188 Factory(const std::string& name, 1189 const std::vector<Sample>* custom_ranges, 1190 int32_t flags) 1191 : Histogram::Factory(name, CUSTOM_HISTOGRAM, 0, 0, 0, flags) { 1192 custom_ranges_ = custom_ranges; 1193 } 1194 ~Factory() override = default; 1195 1196 protected: 1197 BucketRanges* CreateRanges() override { 1198 // Remove the duplicates in the custom ranges array. 1199 std::vector<int> ranges = *custom_ranges_; 1200 ranges.push_back(0); // Ensure we have a zero value. 1201 ranges.push_back(HistogramBase::kSampleType_MAX); 1202 std::sort(ranges.begin(), ranges.end()); 1203 ranges.erase(std::unique(ranges.begin(), ranges.end()), ranges.end()); 1204 1205 BucketRanges* bucket_ranges = new BucketRanges(ranges.size()); 1206 for (uint32_t i = 0; i < ranges.size(); i++) { 1207 bucket_ranges->set_range(i, ranges[i]); 1208 } 1209 bucket_ranges->ResetChecksum(); 1210 return bucket_ranges; 1211 } 1212 1213 std::unique_ptr<HistogramBase> HeapAlloc( 1214 const BucketRanges* ranges) override { 1215 return WrapUnique(new CustomHistogram(GetPermanentName(name_), ranges)); 1216 } 1217 1218 private: 1219 const std::vector<Sample>* custom_ranges_; 1220 1221 DISALLOW_COPY_AND_ASSIGN(Factory); 1222 }; 1223 1224 HistogramBase* CustomHistogram::FactoryGet( 1225 const std::string& name, 1226 const std::vector<Sample>& custom_ranges, 1227 int32_t flags) { 1228 CHECK(ValidateCustomRanges(custom_ranges)); 1229 1230 return Factory(name, &custom_ranges, flags).Build(); 1231 } 1232 1233 HistogramBase* CustomHistogram::FactoryGet( 1234 const char* name, 1235 const std::vector<Sample>& custom_ranges, 1236 int32_t flags) { 1237 return FactoryGet(std::string(name), custom_ranges, flags); 1238 } 1239 1240 std::unique_ptr<HistogramBase> CustomHistogram::PersistentCreate( 1241 const char* name, 1242 const BucketRanges* ranges, 1243 const DelayedPersistentAllocation& counts, 1244 const DelayedPersistentAllocation& logged_counts, 1245 HistogramSamples::Metadata* meta, 1246 HistogramSamples::Metadata* logged_meta) { 1247 return WrapUnique(new CustomHistogram(name, ranges, counts, logged_counts, 1248 meta, logged_meta)); 1249 } 1250 1251 HistogramType CustomHistogram::GetHistogramType() const { 1252 return CUSTOM_HISTOGRAM; 1253 } 1254 1255 // static 1256 std::vector<Sample> CustomHistogram::ArrayToCustomEnumRanges( 1257 base::span<const Sample> values) { 1258 std::vector<Sample> all_values; 1259 for (Sample value : values) { 1260 all_values.push_back(value); 1261 1262 // Ensure that a guard bucket is added. If we end up with duplicate 1263 // values, FactoryGet will take care of removing them. 1264 all_values.push_back(value + 1); 1265 } 1266 return all_values; 1267 } 1268 1269 CustomHistogram::CustomHistogram(const char* name, const BucketRanges* ranges) 1270 : Histogram(name, 1271 ranges->range(1), 1272 ranges->range(ranges->bucket_count() - 1), 1273 ranges) {} 1274 1275 CustomHistogram::CustomHistogram( 1276 const char* name, 1277 const BucketRanges* ranges, 1278 const DelayedPersistentAllocation& counts, 1279 const DelayedPersistentAllocation& logged_counts, 1280 HistogramSamples::Metadata* meta, 1281 HistogramSamples::Metadata* logged_meta) 1282 : Histogram(name, 1283 ranges->range(1), 1284 ranges->range(ranges->bucket_count() - 1), 1285 ranges, 1286 counts, 1287 logged_counts, 1288 meta, 1289 logged_meta) {} 1290 1291 void CustomHistogram::SerializeInfoImpl(Pickle* pickle) const { 1292 Histogram::SerializeInfoImpl(pickle); 1293 1294 // Serialize ranges. First and last ranges are alwasy 0 and INT_MAX, so don't 1295 // write them. 1296 for (uint32_t i = 1; i < bucket_ranges()->bucket_count(); ++i) 1297 pickle->WriteInt(bucket_ranges()->range(i)); 1298 } 1299 1300 double CustomHistogram::GetBucketSize(Count current, uint32_t i) const { 1301 // If this is a histogram of enum values, normalizing the bucket count 1302 // by the bucket range is not helpful, so just return the bucket count. 1303 return current; 1304 } 1305 1306 // static 1307 HistogramBase* CustomHistogram::DeserializeInfoImpl(PickleIterator* iter) { 1308 std::string histogram_name; 1309 int flags; 1310 int declared_min; 1311 int declared_max; 1312 uint32_t bucket_count; 1313 uint32_t range_checksum; 1314 1315 if (!ReadHistogramArguments(iter, &histogram_name, &flags, &declared_min, 1316 &declared_max, &bucket_count, &range_checksum)) { 1317 return nullptr; 1318 } 1319 1320 // First and last ranges are not serialized. 1321 std::vector<Sample> sample_ranges(bucket_count - 1); 1322 1323 for (uint32_t i = 0; i < sample_ranges.size(); ++i) { 1324 if (!iter->ReadInt(&sample_ranges[i])) 1325 return nullptr; 1326 } 1327 1328 HistogramBase* histogram = CustomHistogram::FactoryGet( 1329 histogram_name, sample_ranges, flags); 1330 if (!histogram) 1331 return nullptr; 1332 1333 if (!ValidateRangeChecksum(*histogram, range_checksum)) { 1334 // The serialized histogram might be corrupted. 1335 return nullptr; 1336 } 1337 return histogram; 1338 } 1339 1340 // static 1341 bool CustomHistogram::ValidateCustomRanges( 1342 const std::vector<Sample>& custom_ranges) { 1343 bool has_valid_range = false; 1344 for (uint32_t i = 0; i < custom_ranges.size(); i++) { 1345 Sample sample = custom_ranges[i]; 1346 if (sample < 0 || sample > HistogramBase::kSampleType_MAX - 1) 1347 return false; 1348 if (sample != 0) 1349 has_valid_range = true; 1350 } 1351 return has_valid_range; 1352 } 1353 1354 } // namespace base 1355
