| // Copyright (c) 2010 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| // Histogram is an object that aggregates statistics, and can summarize them in |
| // various forms, including ASCII graphical, HTML, and numerically (as a |
| // vector of numbers corresponding to each of the aggregating buckets). |
| // See header file for details and examples. |
| |
| #include "base/histogram.h" |
| |
| #include <math.h> |
| |
| #include <algorithm> |
| #include <string> |
| |
| #include "base/lock.h" |
| #include "base/logging.h" |
| #include "base/pickle.h" |
| #include "base/stringprintf.h" |
| |
| using base::TimeDelta; |
| |
| typedef Histogram::Count Count; |
| |
| scoped_refptr<Histogram> Histogram::FactoryGet(const std::string& name, |
| Sample minimum, Sample maximum, size_t bucket_count, Flags flags) { |
| scoped_refptr<Histogram> histogram(NULL); |
| |
| // Defensive code. |
| if (minimum <= 0) |
| minimum = 1; |
| if (maximum >= kSampleType_MAX) |
| maximum = kSampleType_MAX - 1; |
| |
| if (!StatisticsRecorder::FindHistogram(name, &histogram)) { |
| histogram = new Histogram(name, minimum, maximum, bucket_count); |
| StatisticsRecorder::FindHistogram(name, &histogram); |
| } |
| |
| DCHECK(HISTOGRAM == histogram->histogram_type()); |
| DCHECK(histogram->HasConstructorArguments(minimum, maximum, bucket_count)); |
| histogram->SetFlags(flags); |
| return histogram; |
| } |
| |
| scoped_refptr<Histogram> Histogram::FactoryTimeGet(const std::string& name, |
| base::TimeDelta minimum, base::TimeDelta maximum, size_t bucket_count, |
| Flags flags) { |
| return FactoryGet(name, minimum.InMilliseconds(), maximum.InMilliseconds(), |
| bucket_count, flags); |
| } |
| |
| Histogram::Histogram(const std::string& name, Sample minimum, |
| Sample maximum, size_t bucket_count) |
| : histogram_name_(name), |
| declared_min_(minimum), |
| declared_max_(maximum), |
| bucket_count_(bucket_count), |
| flags_(kNoFlags), |
| ranges_(bucket_count + 1, 0), |
| sample_() { |
| Initialize(); |
| } |
| |
| Histogram::Histogram(const std::string& name, TimeDelta minimum, |
| TimeDelta maximum, size_t bucket_count) |
| : histogram_name_(name), |
| declared_min_(static_cast<int> (minimum.InMilliseconds())), |
| declared_max_(static_cast<int> (maximum.InMilliseconds())), |
| bucket_count_(bucket_count), |
| flags_(kNoFlags), |
| ranges_(bucket_count + 1, 0), |
| sample_() { |
| Initialize(); |
| } |
| |
| Histogram::~Histogram() { |
| if (StatisticsRecorder::dump_on_exit()) { |
| std::string output; |
| WriteAscii(true, "\n", &output); |
| LOG(INFO) << output; |
| } |
| |
| // Just to make sure most derived class did this properly... |
| DCHECK(ValidateBucketRanges()); |
| } |
| |
| bool Histogram::PrintEmptyBucket(size_t index) const { |
| return true; |
| } |
| |
| void Histogram::Add(int value) { |
| if (value >= kSampleType_MAX) |
| value = kSampleType_MAX - 1; |
| if (value < 0) |
| value = 0; |
| size_t index = BucketIndex(value); |
| DCHECK(value >= ranges(index)); |
| DCHECK(value < ranges(index + 1)); |
| Accumulate(value, 1, index); |
| } |
| |
| void Histogram::AddBoolean(bool value) { |
| DCHECK(false); |
| } |
| |
| void Histogram::AddSampleSet(const SampleSet& sample) { |
| sample_.Add(sample); |
| } |
| |
| void Histogram::SetRangeDescriptions(const DescriptionPair descriptions[]) { |
| DCHECK(false); |
| } |
| |
| // The following methods provide a graphical histogram display. |
| void Histogram::WriteHTMLGraph(std::string* output) const { |
| // TBD(jar) Write a nice HTML bar chart, with divs an mouse-overs etc. |
| output->append("<PRE>"); |
| WriteAscii(true, "<br>", output); |
| output->append("</PRE>"); |
| } |
| |
| void Histogram::WriteAscii(bool graph_it, const std::string& newline, |
| std::string* output) const { |
| // Get local (stack) copies of all effectively volatile class data so that we |
| // are consistent across our output activities. |
| SampleSet snapshot; |
| SnapshotSample(&snapshot); |
| Count sample_count = snapshot.TotalCount(); |
| |
| WriteAsciiHeader(snapshot, sample_count, output); |
| output->append(newline); |
| |
| // Prepare to normalize graphical rendering of bucket contents. |
| double max_size = 0; |
| if (graph_it) |
| max_size = GetPeakBucketSize(snapshot); |
| |
| // Calculate space needed to print bucket range numbers. Leave room to print |
| // nearly the largest bucket range without sliding over the histogram. |
| size_t largest_non_empty_bucket = bucket_count() - 1; |
| while (0 == snapshot.counts(largest_non_empty_bucket)) { |
| if (0 == largest_non_empty_bucket) |
| break; // All buckets are empty. |
| --largest_non_empty_bucket; |
| } |
| |
| // Calculate largest print width needed for any of our bucket range displays. |
| size_t print_width = 1; |
| for (size_t i = 0; i < bucket_count(); ++i) { |
| if (snapshot.counts(i)) { |
| size_t width = GetAsciiBucketRange(i).size() + 1; |
| if (width > print_width) |
| print_width = width; |
| } |
| } |
| |
| int64 remaining = sample_count; |
| int64 past = 0; |
| // Output the actual histogram graph. |
| for (size_t i = 0; i < bucket_count(); ++i) { |
| Count current = snapshot.counts(i); |
| if (!current && !PrintEmptyBucket(i)) |
| continue; |
| remaining -= current; |
| std::string range = GetAsciiBucketRange(i); |
| output->append(range); |
| for (size_t j = 0; range.size() + j < print_width + 1; ++j) |
| output->push_back(' '); |
| if (0 == current && i < bucket_count() - 1 && 0 == snapshot.counts(i + 1)) { |
| while (i < bucket_count() - 1 && 0 == snapshot.counts(i + 1)) |
| ++i; |
| output->append("... "); |
| output->append(newline); |
| continue; // No reason to plot emptiness. |
| } |
| double current_size = GetBucketSize(current, i); |
| if (graph_it) |
| WriteAsciiBucketGraph(current_size, max_size, output); |
| WriteAsciiBucketContext(past, current, remaining, i, output); |
| output->append(newline); |
| past += current; |
| } |
| DCHECK(past == sample_count); |
| } |
| |
| bool Histogram::ValidateBucketRanges() const { |
| // Standard assertions that all bucket ranges should satisfy. |
| DCHECK(ranges_.size() == bucket_count_ + 1); |
| DCHECK_EQ(ranges_[0], 0); |
| DCHECK(declared_min() == ranges_[1]); |
| DCHECK(declared_max() == ranges_[bucket_count_ - 1]); |
| DCHECK(kSampleType_MAX == ranges_[bucket_count_]); |
| return true; |
| } |
| |
| void Histogram::Initialize() { |
| sample_.Resize(*this); |
| if (declared_min_ <= 0) |
| declared_min_ = 1; |
| if (declared_max_ >= kSampleType_MAX) |
| declared_max_ = kSampleType_MAX - 1; |
| DCHECK(declared_min_ <= declared_max_); |
| DCHECK_GT(bucket_count_, 1u); |
| size_t maximal_bucket_count = declared_max_ - declared_min_ + 2; |
| DCHECK(bucket_count_ <= maximal_bucket_count); |
| DCHECK_EQ(ranges_[0], 0); |
| ranges_[bucket_count_] = kSampleType_MAX; |
| InitializeBucketRange(); |
| DCHECK(ValidateBucketRanges()); |
| StatisticsRecorder::Register(this); |
| } |
| |
| // Calculate what range of values are held in each bucket. |
| // We have to be careful that we don't pick a ratio between starting points in |
| // consecutive buckets that is sooo small, that the integer bounds are the same |
| // (effectively making one bucket get no values). We need to avoid: |
| // (ranges_[i] == ranges_[i + 1] |
| // To avoid that, we just do a fine-grained bucket width as far as we need to |
| // until we get a ratio that moves us along at least 2 units at a time. From |
| // that bucket onward we do use the exponential growth of buckets. |
| void Histogram::InitializeBucketRange() { |
| double log_max = log(static_cast<double>(declared_max())); |
| double log_ratio; |
| double log_next; |
| size_t bucket_index = 1; |
| Sample current = declared_min(); |
| SetBucketRange(bucket_index, current); |
| while (bucket_count() > ++bucket_index) { |
| double log_current; |
| log_current = log(static_cast<double>(current)); |
| // Calculate the count'th root of the range. |
| log_ratio = (log_max - log_current) / (bucket_count() - bucket_index); |
| // See where the next bucket would start. |
| log_next = log_current + log_ratio; |
| int next; |
| next = static_cast<int>(floor(exp(log_next) + 0.5)); |
| if (next > current) |
| current = next; |
| else |
| ++current; // Just do a narrow bucket, and keep trying. |
| SetBucketRange(bucket_index, current); |
| } |
| |
| DCHECK(bucket_count() == bucket_index); |
| } |
| |
| size_t Histogram::BucketIndex(Sample value) const { |
| // Use simple binary search. This is very general, but there are better |
| // approaches if we knew that the buckets were linearly distributed. |
| DCHECK(ranges(0) <= value); |
| DCHECK(ranges(bucket_count()) > value); |
| size_t under = 0; |
| size_t over = bucket_count(); |
| size_t mid; |
| |
| do { |
| DCHECK(over >= under); |
| mid = (over + under)/2; |
| if (mid == under) |
| break; |
| if (ranges(mid) <= value) |
| under = mid; |
| else |
| over = mid; |
| } while (true); |
| |
| DCHECK(ranges(mid) <= value && ranges(mid+1) > value); |
| return mid; |
| } |
| |
| // Use the actual bucket widths (like a linear histogram) until the widths get |
| // over some transition value, and then use that transition width. Exponentials |
| // get so big so fast (and we don't expect to see a lot of entries in the large |
| // buckets), so we need this to make it possible to see what is going on and |
| // not have 0-graphical-height buckets. |
| double Histogram::GetBucketSize(Count current, size_t i) const { |
| DCHECK(ranges(i + 1) > ranges(i)); |
| static const double kTransitionWidth = 5; |
| double denominator = ranges(i + 1) - ranges(i); |
| if (denominator > kTransitionWidth) |
| denominator = kTransitionWidth; // Stop trying to normalize. |
| return current/denominator; |
| } |
| |
| //------------------------------------------------------------------------------ |
| // The following two methods can be overridden to provide a thread safe |
| // version of this class. The cost of locking is low... but an error in each |
| // of these methods has minimal impact. For now, I'll leave this unlocked, |
| // and I don't believe I can loose more than a count or two. |
| // The vectors are NOT reallocated, so there is no risk of them moving around. |
| |
| // Update histogram data with new sample. |
| void Histogram::Accumulate(Sample value, Count count, size_t index) { |
| // Note locking not done in this version!!! |
| sample_.Accumulate(value, count, index); |
| } |
| |
| // Do a safe atomic snapshot of sample data. |
| // This implementation assumes we are on a safe single thread. |
| void Histogram::SnapshotSample(SampleSet* sample) const { |
| // Note locking not done in this version!!! |
| *sample = sample_; |
| } |
| |
| bool Histogram::HasConstructorArguments(Sample minimum, Sample maximum, |
| size_t bucket_count) { |
| return ((minimum == declared_min_) && (maximum == declared_max_) && |
| (bucket_count == bucket_count_)); |
| } |
| |
| bool Histogram::HasConstructorTimeDeltaArguments(base::TimeDelta minimum, |
| base::TimeDelta maximum, |
| size_t bucket_count) { |
| return ((minimum.InMilliseconds() == declared_min_) && |
| (maximum.InMilliseconds() == declared_max_) && |
| (bucket_count == bucket_count_)); |
| } |
| |
| //------------------------------------------------------------------------------ |
| // Accessor methods |
| |
| void Histogram::SetBucketRange(size_t i, Sample value) { |
| DCHECK(bucket_count_ > i); |
| ranges_[i] = value; |
| } |
| |
| //------------------------------------------------------------------------------ |
| // Private methods |
| |
| double Histogram::GetPeakBucketSize(const SampleSet& snapshot) const { |
| double max = 0; |
| for (size_t i = 0; i < bucket_count() ; ++i) { |
| double current_size = GetBucketSize(snapshot.counts(i), i); |
| if (current_size > max) |
| max = current_size; |
| } |
| return max; |
| } |
| |
| void Histogram::WriteAsciiHeader(const SampleSet& snapshot, |
| Count sample_count, |
| std::string* output) const { |
| base::StringAppendF(output, |
| "Histogram: %s recorded %d samples", |
| histogram_name().c_str(), |
| sample_count); |
| if (0 == sample_count) { |
| DCHECK_EQ(snapshot.sum(), 0); |
| } else { |
| double average = static_cast<float>(snapshot.sum()) / sample_count; |
| double variance = static_cast<float>(snapshot.square_sum())/sample_count |
| - average * average; |
| double standard_deviation = sqrt(variance); |
| |
| base::StringAppendF(output, |
| ", average = %.1f, standard deviation = %.1f", |
| average, standard_deviation); |
| } |
| if (flags_ & ~kHexRangePrintingFlag ) |
| base::StringAppendF(output, " (flags = 0x%x)", |
| flags_ & ~kHexRangePrintingFlag); |
| } |
| |
| void Histogram::WriteAsciiBucketContext(const int64 past, |
| const Count current, |
| const int64 remaining, |
| const size_t i, |
| std::string* output) const { |
| double scaled_sum = (past + current + remaining) / 100.0; |
| WriteAsciiBucketValue(current, scaled_sum, output); |
| if (0 < i) { |
| double percentage = past / scaled_sum; |
| base::StringAppendF(output, " {%3.1f%%}", percentage); |
| } |
| } |
| |
| const std::string Histogram::GetAsciiBucketRange(size_t i) const { |
| std::string result; |
| if (kHexRangePrintingFlag & flags_) |
| base::StringAppendF(&result, "%#x", ranges(i)); |
| else |
| base::StringAppendF(&result, "%d", ranges(i)); |
| return result; |
| } |
| |
| void Histogram::WriteAsciiBucketValue(Count current, double scaled_sum, |
| std::string* output) const { |
| base::StringAppendF(output, " (%d = %3.1f%%)", current, current/scaled_sum); |
| } |
| |
| void Histogram::WriteAsciiBucketGraph(double current_size, double max_size, |
| std::string* output) const { |
| const int k_line_length = 72; // Maximal horizontal width of graph. |
| int x_count = static_cast<int>(k_line_length * (current_size / max_size) |
| + 0.5); |
| int x_remainder = k_line_length - x_count; |
| |
| while (0 < x_count--) |
| output->append("-"); |
| output->append("O"); |
| while (0 < x_remainder--) |
| output->append(" "); |
| } |
| |
| // static |
| std::string Histogram::SerializeHistogramInfo(const Histogram& histogram, |
| const SampleSet& snapshot) { |
| DCHECK(histogram.histogram_type() != NOT_VALID_IN_RENDERER); |
| |
| Pickle pickle; |
| pickle.WriteString(histogram.histogram_name()); |
| pickle.WriteInt(histogram.declared_min()); |
| pickle.WriteInt(histogram.declared_max()); |
| pickle.WriteSize(histogram.bucket_count()); |
| pickle.WriteInt(histogram.histogram_type()); |
| pickle.WriteInt(histogram.flags()); |
| |
| snapshot.Serialize(&pickle); |
| return std::string(static_cast<const char*>(pickle.data()), pickle.size()); |
| } |
| |
| // static |
| bool Histogram::DeserializeHistogramInfo(const std::string& histogram_info) { |
| if (histogram_info.empty()) { |
| return false; |
| } |
| |
| Pickle pickle(histogram_info.data(), |
| static_cast<int>(histogram_info.size())); |
| void* iter = NULL; |
| size_t bucket_count; |
| int declared_min; |
| int declared_max; |
| int histogram_type; |
| int pickle_flags; |
| std::string histogram_name; |
| SampleSet sample; |
| |
| if (!pickle.ReadString(&iter, &histogram_name) || |
| !pickle.ReadInt(&iter, &declared_min) || |
| !pickle.ReadInt(&iter, &declared_max) || |
| !pickle.ReadSize(&iter, &bucket_count) || |
| !pickle.ReadInt(&iter, &histogram_type) || |
| !pickle.ReadInt(&iter, &pickle_flags) || |
| !sample.Histogram::SampleSet::Deserialize(&iter, pickle)) { |
| LOG(ERROR) << "Pickle error decoding Histogram: " << histogram_name; |
| return false; |
| } |
| DCHECK(pickle_flags & kIPCSerializationSourceFlag); |
| // Since these fields may have come from an untrusted renderer, do additional |
| // checks above and beyond those in Histogram::Initialize() |
| if (declared_max <= 0 || declared_min <= 0 || declared_max < declared_min || |
| INT_MAX / sizeof(Count) <= bucket_count || bucket_count < 2) { |
| LOG(ERROR) << "Values error decoding Histogram: " << histogram_name; |
| return false; |
| } |
| |
| Flags flags = static_cast<Flags>(pickle_flags & ~kIPCSerializationSourceFlag); |
| |
| DCHECK(histogram_type != NOT_VALID_IN_RENDERER); |
| |
| scoped_refptr<Histogram> render_histogram(NULL); |
| |
| if (histogram_type == HISTOGRAM) { |
| render_histogram = Histogram::FactoryGet( |
| histogram_name, declared_min, declared_max, bucket_count, flags); |
| } else if (histogram_type == LINEAR_HISTOGRAM) { |
| render_histogram = LinearHistogram::FactoryGet( |
| histogram_name, declared_min, declared_max, bucket_count, flags); |
| } else if (histogram_type == BOOLEAN_HISTOGRAM) { |
| render_histogram = BooleanHistogram::FactoryGet(histogram_name, flags); |
| } else { |
| LOG(ERROR) << "Error Deserializing Histogram Unknown histogram_type: " << |
| histogram_type; |
| return false; |
| } |
| |
| DCHECK(declared_min == render_histogram->declared_min()); |
| DCHECK(declared_max == render_histogram->declared_max()); |
| DCHECK(bucket_count == render_histogram->bucket_count()); |
| DCHECK(histogram_type == render_histogram->histogram_type()); |
| |
| if (render_histogram->flags() & kIPCSerializationSourceFlag) { |
| DLOG(INFO) << "Single process mode, histogram observed and not copied: " << |
| histogram_name; |
| } else { |
| DCHECK(flags == (flags & render_histogram->flags())); |
| render_histogram->AddSampleSet(sample); |
| } |
| |
| return true; |
| } |
| |
| //------------------------------------------------------------------------------ |
| // Methods for the Histogram::SampleSet class |
| //------------------------------------------------------------------------------ |
| |
| Histogram::SampleSet::SampleSet() |
| : counts_(), |
| sum_(0), |
| square_sum_(0) { |
| } |
| |
| Histogram::SampleSet::~SampleSet() { |
| } |
| |
| void Histogram::SampleSet::Resize(const Histogram& histogram) { |
| counts_.resize(histogram.bucket_count(), 0); |
| } |
| |
| void Histogram::SampleSet::CheckSize(const Histogram& histogram) const { |
| DCHECK(counts_.size() == histogram.bucket_count()); |
| } |
| |
| |
| void Histogram::SampleSet::Accumulate(Sample value, Count count, |
| size_t index) { |
| DCHECK(count == 1 || count == -1); |
| counts_[index] += count; |
| sum_ += count * value; |
| square_sum_ += (count * value) * static_cast<int64>(value); |
| DCHECK_GE(counts_[index], 0); |
| DCHECK_GE(sum_, 0); |
| DCHECK_GE(square_sum_, 0); |
| } |
| |
| Count Histogram::SampleSet::TotalCount() const { |
| Count total = 0; |
| for (Counts::const_iterator it = counts_.begin(); |
| it != counts_.end(); |
| ++it) { |
| total += *it; |
| } |
| return total; |
| } |
| |
| void Histogram::SampleSet::Add(const SampleSet& other) { |
| DCHECK(counts_.size() == other.counts_.size()); |
| sum_ += other.sum_; |
| square_sum_ += other.square_sum_; |
| for (size_t index = 0; index < counts_.size(); ++index) |
| counts_[index] += other.counts_[index]; |
| } |
| |
| void Histogram::SampleSet::Subtract(const SampleSet& other) { |
| DCHECK(counts_.size() == other.counts_.size()); |
| // Note: Race conditions in snapshotting a sum or square_sum may lead to |
| // (temporary) negative values when snapshots are later combined (and deltas |
| // calculated). As a result, we don't currently CHCEK() for positive values. |
| sum_ -= other.sum_; |
| square_sum_ -= other.square_sum_; |
| for (size_t index = 0; index < counts_.size(); ++index) { |
| counts_[index] -= other.counts_[index]; |
| DCHECK_GE(counts_[index], 0); |
| } |
| } |
| |
| bool Histogram::SampleSet::Serialize(Pickle* pickle) const { |
| pickle->WriteInt64(sum_); |
| pickle->WriteInt64(square_sum_); |
| pickle->WriteSize(counts_.size()); |
| |
| for (size_t index = 0; index < counts_.size(); ++index) { |
| pickle->WriteInt(counts_[index]); |
| } |
| |
| return true; |
| } |
| |
| bool Histogram::SampleSet::Deserialize(void** iter, const Pickle& pickle) { |
| DCHECK_EQ(counts_.size(), 0u); |
| DCHECK_EQ(sum_, 0); |
| DCHECK_EQ(square_sum_, 0); |
| |
| size_t counts_size; |
| |
| if (!pickle.ReadInt64(iter, &sum_) || |
| !pickle.ReadInt64(iter, &square_sum_) || |
| !pickle.ReadSize(iter, &counts_size)) { |
| return false; |
| } |
| |
| if (counts_size == 0) |
| return false; |
| |
| for (size_t index = 0; index < counts_size; ++index) { |
| int i; |
| if (!pickle.ReadInt(iter, &i)) |
| return false; |
| counts_.push_back(i); |
| } |
| |
| return true; |
| } |
| |
| //------------------------------------------------------------------------------ |
| // LinearHistogram: This histogram uses a traditional set of evenly spaced |
| // buckets. |
| //------------------------------------------------------------------------------ |
| |
| scoped_refptr<Histogram> LinearHistogram::FactoryGet( |
| const std::string& name, Sample minimum, Sample maximum, |
| size_t bucket_count, Flags flags) { |
| scoped_refptr<Histogram> histogram(NULL); |
| |
| if (minimum <= 0) |
| minimum = 1; |
| if (maximum >= kSampleType_MAX) |
| maximum = kSampleType_MAX - 1; |
| |
| if (!StatisticsRecorder::FindHistogram(name, &histogram)) { |
| histogram = new LinearHistogram(name, minimum, maximum, bucket_count); |
| StatisticsRecorder::FindHistogram(name, &histogram); |
| } |
| |
| DCHECK(LINEAR_HISTOGRAM == histogram->histogram_type()); |
| DCHECK(histogram->HasConstructorArguments(minimum, maximum, bucket_count)); |
| histogram->SetFlags(flags); |
| return histogram; |
| } |
| |
| scoped_refptr<Histogram> LinearHistogram::FactoryTimeGet( |
| const std::string& name, base::TimeDelta minimum, base::TimeDelta maximum, |
| size_t bucket_count, Flags flags) { |
| return FactoryGet(name, minimum.InMilliseconds(), maximum.InMilliseconds(), |
| bucket_count, flags); |
| } |
| |
| LinearHistogram::~LinearHistogram() { |
| } |
| |
| LinearHistogram::LinearHistogram(const std::string& name, Sample minimum, |
| Sample maximum, size_t bucket_count) |
| : Histogram(name, minimum >= 1 ? minimum : 1, maximum, bucket_count) { |
| InitializeBucketRange(); |
| DCHECK(ValidateBucketRanges()); |
| } |
| |
| LinearHistogram::LinearHistogram(const std::string& name, |
| TimeDelta minimum, TimeDelta maximum, size_t bucket_count) |
| : Histogram(name, minimum >= TimeDelta::FromMilliseconds(1) ? |
| minimum : TimeDelta::FromMilliseconds(1), |
| maximum, bucket_count) { |
| // Do a "better" (different) job at init than a base classes did... |
| InitializeBucketRange(); |
| DCHECK(ValidateBucketRanges()); |
| } |
| |
| Histogram::ClassType LinearHistogram::histogram_type() const { |
| return LINEAR_HISTOGRAM; |
| } |
| |
| void LinearHistogram::SetRangeDescriptions( |
| const DescriptionPair descriptions[]) { |
| for (int i =0; descriptions[i].description; ++i) { |
| bucket_description_[descriptions[i].sample] = descriptions[i].description; |
| } |
| } |
| |
| const std::string LinearHistogram::GetAsciiBucketRange(size_t i) const { |
| int range = ranges(i); |
| BucketDescriptionMap::const_iterator it = bucket_description_.find(range); |
| if (it == bucket_description_.end()) |
| return Histogram::GetAsciiBucketRange(i); |
| return it->second; |
| } |
| |
| bool LinearHistogram::PrintEmptyBucket(size_t index) const { |
| return bucket_description_.find(ranges(index)) == bucket_description_.end(); |
| } |
| |
| |
| void LinearHistogram::InitializeBucketRange() { |
| DCHECK_GT(declared_min(), 0); // 0 is the underflow bucket here. |
| double min = declared_min(); |
| double max = declared_max(); |
| size_t i; |
| for (i = 1; i < bucket_count(); ++i) { |
| double linear_range = (min * (bucket_count() -1 - i) + max * (i - 1)) / |
| (bucket_count() - 2); |
| SetBucketRange(i, static_cast<int> (linear_range + 0.5)); |
| } |
| } |
| |
| double LinearHistogram::GetBucketSize(Count current, size_t i) const { |
| DCHECK(ranges(i + 1) > ranges(i)); |
| // Adjacent buckets with different widths would have "surprisingly" many (few) |
| // samples in a histogram if we didn't normalize this way. |
| double denominator = ranges(i + 1) - ranges(i); |
| return current/denominator; |
| } |
| |
| //------------------------------------------------------------------------------ |
| // This section provides implementation for BooleanHistogram. |
| //------------------------------------------------------------------------------ |
| |
| scoped_refptr<Histogram> BooleanHistogram::FactoryGet(const std::string& name, |
| Flags flags) { |
| scoped_refptr<Histogram> histogram(NULL); |
| |
| if (!StatisticsRecorder::FindHistogram(name, &histogram)) { |
| histogram = new BooleanHistogram(name); |
| StatisticsRecorder::FindHistogram(name, &histogram); |
| } |
| |
| DCHECK(BOOLEAN_HISTOGRAM == histogram->histogram_type()); |
| histogram->SetFlags(flags); |
| return histogram; |
| } |
| |
| Histogram::ClassType BooleanHistogram::histogram_type() const { |
| return BOOLEAN_HISTOGRAM; |
| } |
| |
| void BooleanHistogram::AddBoolean(bool value) { |
| Add(value ? 1 : 0); |
| } |
| |
| BooleanHistogram::BooleanHistogram(const std::string& name) |
| : LinearHistogram(name, 1, 2, 3) { |
| } |
| |
| //------------------------------------------------------------------------------ |
| // CustomHistogram: |
| //------------------------------------------------------------------------------ |
| |
| scoped_refptr<Histogram> CustomHistogram::FactoryGet( |
| const std::string& name, const std::vector<int>& custom_ranges, |
| Flags flags) { |
| scoped_refptr<Histogram> histogram(NULL); |
| |
| // Remove the duplicates in the custom ranges array. |
| std::vector<int> ranges = custom_ranges; |
| ranges.push_back(0); // Ensure we have a zero value. |
| std::sort(ranges.begin(), ranges.end()); |
| ranges.erase(std::unique(ranges.begin(), ranges.end()), ranges.end()); |
| if (ranges.size() <= 1) { |
| DCHECK(false); |
| // Note that we pushed a 0 in above, so for defensive code.... |
| ranges.push_back(1); // Put in some data so we can index to [1]. |
| } |
| |
| DCHECK_LT(ranges.back(), kSampleType_MAX); |
| |
| if (!StatisticsRecorder::FindHistogram(name, &histogram)) { |
| histogram = new CustomHistogram(name, ranges); |
| StatisticsRecorder::FindHistogram(name, &histogram); |
| } |
| |
| DCHECK_EQ(histogram->histogram_type(), CUSTOM_HISTOGRAM); |
| DCHECK(histogram->HasConstructorArguments(ranges[1], ranges.back(), |
| ranges.size())); |
| histogram->SetFlags(flags); |
| return histogram; |
| } |
| |
| Histogram::ClassType CustomHistogram::histogram_type() const { |
| return CUSTOM_HISTOGRAM; |
| } |
| |
| CustomHistogram::CustomHistogram(const std::string& name, |
| const std::vector<int>& custom_ranges) |
| : Histogram(name, custom_ranges[1], custom_ranges.back(), |
| custom_ranges.size()) { |
| DCHECK_GT(custom_ranges.size(), 1u); |
| DCHECK_EQ(custom_ranges[0], 0); |
| ranges_vector_ = &custom_ranges; |
| InitializeBucketRange(); |
| ranges_vector_ = NULL; |
| DCHECK(ValidateBucketRanges()); |
| } |
| |
| void CustomHistogram::InitializeBucketRange() { |
| DCHECK(ranges_vector_->size() <= bucket_count()); |
| for (size_t index = 0; index < ranges_vector_->size(); ++index) { |
| SetBucketRange(index, (*ranges_vector_)[index]); |
| } |
| } |
| |
| double CustomHistogram::GetBucketSize(Count current, size_t i) const { |
| return 1; |
| } |
| |
| //------------------------------------------------------------------------------ |
| // The next section handles global (central) support for all histograms, as well |
| // as startup/teardown of this service. |
| //------------------------------------------------------------------------------ |
| |
| // This singleton instance should be started during the single threaded portion |
| // of main(), and hence it is not thread safe. It initializes globals to |
| // provide support for all future calls. |
| StatisticsRecorder::StatisticsRecorder() { |
| DCHECK(!histograms_); |
| lock_ = new Lock; |
| histograms_ = new HistogramMap; |
| } |
| |
| StatisticsRecorder::~StatisticsRecorder() { |
| DCHECK(histograms_); |
| |
| if (dump_on_exit_) { |
| std::string output; |
| WriteGraph("", &output); |
| LOG(INFO) << output; |
| } |
| // Clean up. |
| delete histograms_; |
| histograms_ = NULL; |
| delete lock_; |
| lock_ = NULL; |
| } |
| |
| // static |
| bool StatisticsRecorder::WasStarted() { |
| return NULL != histograms_; |
| } |
| |
| // Note: We can't accept a ref_ptr to |histogram| because we *might* not keep a |
| // reference, and we are called while in the Histogram constructor. In that |
| // scenario, a ref_ptr would have incremented the ref count when the histogram |
| // was passed to us, decremented it when we returned, and the instance would be |
| // destroyed before assignment (when value was returned by new). |
| // static |
| void StatisticsRecorder::Register(Histogram* histogram) { |
| if (!histograms_) |
| return; |
| const std::string name = histogram->histogram_name(); |
| AutoLock auto_lock(*lock_); |
| // Avoid overwriting a previous registration. |
| if (histograms_->end() == histograms_->find(name)) |
| (*histograms_)[name] = histogram; |
| } |
| |
| // static |
| void StatisticsRecorder::WriteHTMLGraph(const std::string& query, |
| std::string* output) { |
| if (!histograms_) |
| return; |
| output->append("<html><head><title>About Histograms"); |
| if (!query.empty()) |
| output->append(" - " + query); |
| output->append("</title>" |
| // We'd like the following no-cache... but it doesn't work. |
| // "<META HTTP-EQUIV=\"Pragma\" CONTENT=\"no-cache\">" |
| "</head><body>"); |
| |
| Histograms snapshot; |
| GetSnapshot(query, &snapshot); |
| for (Histograms::iterator it = snapshot.begin(); |
| it != snapshot.end(); |
| ++it) { |
| (*it)->WriteHTMLGraph(output); |
| output->append("<br><hr><br>"); |
| } |
| output->append("</body></html>"); |
| } |
| |
| // static |
| void StatisticsRecorder::WriteGraph(const std::string& query, |
| std::string* output) { |
| if (!histograms_) |
| return; |
| if (query.length()) { |
| base::StringAppendF(output, "Collections of histograms for %s\n", |
| query.c_str()); |
| } else { |
| output->append("Collections of all histograms\n"); |
| } |
| |
| Histograms snapshot; |
| GetSnapshot(query, &snapshot); |
| for (Histograms::iterator it = snapshot.begin(); |
| it != snapshot.end(); |
| ++it) { |
| (*it)->WriteAscii(true, "\n", output); |
| output->append("\n"); |
| } |
| } |
| |
| // static |
| void StatisticsRecorder::GetHistograms(Histograms* output) { |
| if (!histograms_) |
| return; |
| AutoLock auto_lock(*lock_); |
| for (HistogramMap::iterator it = histograms_->begin(); |
| histograms_->end() != it; |
| ++it) { |
| DCHECK(it->second->histogram_name() == it->first); |
| output->push_back(it->second); |
| } |
| } |
| |
| bool StatisticsRecorder::FindHistogram(const std::string& name, |
| scoped_refptr<Histogram>* histogram) { |
| if (!histograms_) |
| return false; |
| AutoLock auto_lock(*lock_); |
| HistogramMap::iterator it = histograms_->find(name); |
| if (histograms_->end() == it) |
| return false; |
| *histogram = it->second; |
| return true; |
| } |
| |
| // private static |
| void StatisticsRecorder::GetSnapshot(const std::string& query, |
| Histograms* snapshot) { |
| AutoLock auto_lock(*lock_); |
| for (HistogramMap::iterator it = histograms_->begin(); |
| histograms_->end() != it; |
| ++it) { |
| if (it->first.find(query) != std::string::npos) |
| snapshot->push_back(it->second); |
| } |
| } |
| |
| // static |
| StatisticsRecorder::HistogramMap* StatisticsRecorder::histograms_ = NULL; |
| // static |
| Lock* StatisticsRecorder::lock_ = NULL; |
| // static |
| bool StatisticsRecorder::dump_on_exit_ = false; |