// Copyright 2014 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/metrics/histogram_encoder.h" #include #include #include "base/metrics/histogram.h" #include "base/metrics/histogram_samples.h" #include "base/metrics/metrics_hashes.h" using base::SampleCountIterator; namespace metrics { void EncodeHistogramDelta(const std::string& histogram_name, const base::HistogramSamples& snapshot, ChromeUserMetricsExtension* uma_proto) { DCHECK_NE(0, snapshot.TotalCount()); DCHECK(uma_proto); // We will ignore the MAX_INT/infinite value in the last element of range[]. HistogramEventProto* histogram_proto = uma_proto->add_histogram_event(); histogram_proto->set_name_hash(base::HashMetricName(histogram_name)); if (snapshot.sum() != 0) histogram_proto->set_sum(snapshot.sum()); for (std::unique_ptr it = snapshot.Iterator(); !it->Done(); it->Next()) { base::Histogram::Sample min; int64_t max; base::Histogram::Count count; it->Get(&min, &max, &count); HistogramEventProto::Bucket* bucket = histogram_proto->add_bucket(); bucket->set_min(min); bucket->set_max(max); // Note: The default for count is 1 in the proto, so omit it in that case. if (count != 1) bucket->set_count(count); } // Omit fields to save space (see rules in histogram_event.proto comments). for (int i = 0; i < histogram_proto->bucket_size(); ++i) { HistogramEventProto::Bucket* bucket = histogram_proto->mutable_bucket(i); if (i + 1 < histogram_proto->bucket_size() && bucket->max() == histogram_proto->bucket(i + 1).min()) { bucket->clear_max(); } else if (bucket->max() == bucket->min() + 1) { bucket->clear_min(); } } } } // namespace metrics