Don't preload rarely seen large images
[chromium-blink-merge.git] / components / rappor / sample.cc
blob1aec6167da59eb037951e3b92536405e66e39048
1 // Copyright 2015 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.
5 #include "components/rappor/sample.h"
7 #include <map>
8 #include <string>
10 #include "base/logging.h"
11 #include "components/metrics/metrics_hashes.h"
12 #include "components/rappor/bloom_filter.h"
13 #include "components/rappor/byte_vector_utils.h"
14 #include "components/rappor/proto/rappor_metric.pb.h"
15 #include "components/rappor/reports.h"
17 namespace rappor {
19 Sample::Sample(int32_t cohort_seed, const RapporParameters& parameters)
20 : parameters_(parameters),
21 bloom_offset_((cohort_seed % parameters_.num_cohorts) *
22 parameters_.bloom_filter_hash_function_count) {
23 // Must use bloom filter size that fits in uint64.
24 DCHECK_LE(parameters_.bloom_filter_size_bytes, 8);
27 Sample::~Sample() {
30 void Sample::SetStringField(const std::string& field_name,
31 const std::string& value) {
32 DCHECK_EQ(0u, sizes_[field_name]);
33 fields_[field_name] = internal::GetBloomBits(
34 parameters_.bloom_filter_size_bytes,
35 parameters_.bloom_filter_hash_function_count,
36 bloom_offset_,
37 value);
38 sizes_[field_name] = parameters_.bloom_filter_size_bytes;
41 void Sample::SetFlagsField(const std::string& field_name,
42 uint64_t flags,
43 size_t num_flags) {
44 DCHECK_EQ(0u, sizes_[field_name]);
45 DCHECK_GT(num_flags, 0u);
46 DCHECK_LE(num_flags, 64u);
47 DCHECK(num_flags == 64u || flags >> num_flags == 0);
48 fields_[field_name] = flags;
49 sizes_[field_name] = (num_flags + 7) / 8;
52 void Sample::ExportMetrics(const std::string& secret,
53 const std::string& metric_name,
54 RapporReports* reports) const {
55 for (const auto& kv : fields_) {
56 uint64_t value = kv.second;
57 const auto it = sizes_.find(kv.first);
58 DCHECK(it != sizes_.end());
59 size_t size = it->second;
60 ByteVector value_bytes(size);
61 Uint64ToByteVector(value, size, &value_bytes);
62 ByteVector report_bytes = internal::GenerateReport(
63 secret, parameters_, value_bytes);
65 RapporReports::Report* report = reports->add_report();
66 report->set_name_hash(metrics::HashMetricName(
67 metric_name + "." + kv.first));
68 report->set_bits(std::string(report_bytes.begin(), report_bytes.end()));
72 } // namespace rappor