Create a histogram serialization mechanism in components/metrics

base/metrics/histogram_sample.cc

+// Copyright (c) 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 <string>
+
+#include "base/logging.h"
+
+#include "base/metrics/chromeos_metrics.h"
+#include "base/metrics/histogram_sample.h"
+#include "base/metrics/metric_sample.h"
+
+using std::string;
+
+namespace base {
+
+HistogramSample::HistogramSample(const std::string& histname,
+  int sample, int min, int max, int nbucket):
+  MetricSample(MetricSample::HISTOGRAM) {
+  name_ = histname;
+  sample_ = sample;
+  min_ = min;
+  max_ = max;
+  nbucket_ = nbucket;
+}
+
+std::string HistogramSample::name() {
+  return name_;
+}
+
+int HistogramSample::sample() {
+  return sample_;
+}
+
+int HistogramSample::min() {
+  return min_;
+}
+
+int HistogramSample::max() {
+  return max_;
+}
+
+int HistogramSample::nbucket() {
+  return nbucket_;
+}
+
+HistogramSample* HistogramSample::ReadHistogram(const std::string& hist_repr) {
+  int sample, min, max, nbucket;
+  char name[128];
+  sscanf(hist_repr.c_str(), "%127s %d %d %d %d", name, &sample, &min, &max,
+         &nbucket);
+  return new HistogramSample(name, sample, min, max, nbucket);
+}
+
+HistogramSample::~HistogramSample() {}
+
+int HistogramSample::Write(int buffer_size, char* buffer) {
+  return ChromeOSMetrics::FormatSample(buffer_size, buffer,
+                              "histogram%c%s %d %d %d %d", '\0', name_.c_str(),
+                              sample_, min_, max_, nbucket_);
+}
+}  // namespace base