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// Copyright 2015 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 "components/rappor/sample.h"
#include <map>
#include <string>
#include "base/logging.h"
#include "base/metrics/metrics_hashes.h"
#include "components/rappor/bloom_filter.h"
#include "components/rappor/byte_vector_utils.h"
#include "components/rappor/proto/rappor_metric.pb.h"
#include "components/rappor/reports.h"
namespace rappor {
Sample::Sample(int32_t cohort_seed, const RapporParameters& parameters)
: parameters_(parameters),
bloom_offset_((cohort_seed % parameters_.num_cohorts) *
parameters_.bloom_filter_hash_function_count) {
// Must use bloom filter size that fits in uint64_t.
DCHECK_LE(parameters_.bloom_filter_size_bytes, 8);
}
Sample::~Sample() {
}
void Sample::SetStringField(const std::string& field_name,
const std::string& value) {
DVLOG(2) << "Recording sample \"" << value
<< "\" for sample metric field \"" << field_name << "\"";
DCHECK_EQ(0u, sizes_[field_name]);
fields_[field_name] = internal::GetBloomBits(
parameters_.bloom_filter_size_bytes,
parameters_.bloom_filter_hash_function_count,
bloom_offset_,
value);
sizes_[field_name] = parameters_.bloom_filter_size_bytes;
}
void Sample::SetFlagsField(const std::string& field_name,
uint64_t flags,
size_t num_flags) {
DVLOG(2) << "Recording flags " << flags
<< " for sample metric field \"" << field_name << "\"";
DCHECK_EQ(0u, sizes_[field_name]);
DCHECK_GT(num_flags, 0u);
DCHECK_LE(num_flags, 64u);
DCHECK(num_flags == 64u || flags >> num_flags == 0);
fields_[field_name] = flags;
sizes_[field_name] = (num_flags + 7) / 8;
}
void Sample::ExportMetrics(const std::string& secret,
const std::string& metric_name,
RapporReports* reports) const {
for (const auto& kv : fields_) {
uint64_t value = kv.second;
const auto it = sizes_.find(kv.first);
DCHECK(it != sizes_.end());
size_t size = it->second;
ByteVector value_bytes(size);
Uint64ToByteVector(value, size, &value_bytes);
ByteVector report_bytes = internal::GenerateReport(
secret,
internal::kNoiseParametersForLevel[parameters_.noise_level],
value_bytes);
RapporReports::Report* report = reports->add_report();
report->set_name_hash(base::HashMetricName(
metric_name + "." + kv.first));
report->set_bits(std::string(report_bytes.begin(), report_bytes.end()));
DVLOG(2) << "Exporting sample " << metric_name << "." << kv.first;
}
}
} // namespace rappor
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