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 <stdio.h>
+
+#include <string>
+
+#include "base/logging.h"
+#include "base/metrics/chromeos_metrics.h"
+#include "base/metrics/histogram_sample.h"
+#include "base/metrics/metric_sample.h"
+#include "base/strings/stringprintf.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;
+}
+
+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];
+  int result = sscanf(hist_repr.c_str(),
+                      "%127s %d %d %d %d",
+                      name,
+                      &sample,
+                      &min,
+                      &max,
+                      &nbucket);
+  if (result != 5) {
+    return NULL;
+  }
+  return new HistogramSample(name, sample, min, max, nbucket);
+}
+
+HistogramSample::~HistogramSample() {}
+
+string HistogramSample::toString() const {
+  return StringPrintf("histogram%c%s %d %d %d %d%c",
+                      '\0',
+                      name_.c_str(),
+                      sample_,
+                      min_,
+                      max_,
+                      nbucket_,
+                      '\0');
+}
+}  // namespace base