blob: b441afa5bf1aaf7d7275da6c7577bf5049658dfe [file] [log] [blame]
// Copyright (c) 2012 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.
#include "base/metrics/sample_map.h"
#include "base/logging.h"
#include "base/memory/ptr_util.h"
#include "base/numerics/safe_conversions.h"
#include "base/stl_util.h"
namespace base {
typedef HistogramBase::Count Count;
typedef HistogramBase::Sample Sample;
namespace {
// An iterator for going through a SampleMap. The logic here is identical
// to that of PersistentSampleMapIterator but with different data structures.
// Changes here likely need to be duplicated there.
class SampleMapIterator : public SampleCountIterator {
public:
typedef std::map<HistogramBase::Sample, HistogramBase::Count>
SampleToCountMap;
explicit SampleMapIterator(const SampleToCountMap& sample_counts);
~SampleMapIterator() override;
// SampleCountIterator:
bool Done() const override;
void Next() override;
void Get(HistogramBase::Sample* min,
int64_t* max,
HistogramBase::Count* count) const override;
private:
void SkipEmptyBuckets();
SampleToCountMap::const_iterator iter_;
const SampleToCountMap::const_iterator end_;
};
SampleMapIterator::SampleMapIterator(const SampleToCountMap& sample_counts)
: iter_(sample_counts.begin()),
end_(sample_counts.end()) {
SkipEmptyBuckets();
}
SampleMapIterator::~SampleMapIterator() = default;
bool SampleMapIterator::Done() const {
return iter_ == end_;
}
void SampleMapIterator::Next() {
DCHECK(!Done());
++iter_;
SkipEmptyBuckets();
}
void SampleMapIterator::Get(Sample* min, int64_t* max, Count* count) const {
DCHECK(!Done());
if (min)
*min = iter_->first;
if (max)
*max = strict_cast<int64_t>(iter_->first) + 1;
if (count)
*count = iter_->second;
}
void SampleMapIterator::SkipEmptyBuckets() {
while (!Done() && iter_->second == 0) {
++iter_;
}
}
} // namespace
SampleMap::SampleMap() : SampleMap(0) {}
SampleMap::SampleMap(uint64_t id) : HistogramSamples(id, new LocalMetadata()) {}
SampleMap::~SampleMap() {
delete static_cast<LocalMetadata*>(meta());
}
void SampleMap::Accumulate(Sample value, Count count) {
sample_counts_[value] += count;
IncreaseSumAndCount(strict_cast<int64_t>(count) * value, count);
}
Count SampleMap::GetCount(Sample value) const {
auto it = sample_counts_.find(value);
if (it == sample_counts_.end())
return 0;
return it->second;
}
Count SampleMap::TotalCount() const {
Count count = 0;
for (const auto& entry : sample_counts_) {
count += entry.second;
}
return count;
}
std::unique_ptr<SampleCountIterator> SampleMap::Iterator() const {
return WrapUnique(new SampleMapIterator(sample_counts_));
}
bool SampleMap::AddSubtractImpl(SampleCountIterator* iter, Operator op) {
Sample min;
int64_t max;
Count count;
for (; !iter->Done(); iter->Next()) {
iter->Get(&min, &max, &count);
if (strict_cast<int64_t>(min) + 1 != max)
return false; // SparseHistogram only supports bucket with size 1.
sample_counts_[min] += (op == HistogramSamples::ADD) ? count : -count;
}
return true;
}
} // namespace base