1 files changed, 89 insertions, 0 deletions
diff --git a/chromium/net/disk_cache/stats_histogram.cc b/chromium/net/disk_cache/stats_histogram.cc
new file mode 100644
index 00000000000..33adfeaae49
--- /dev/null
+++ b/chromium/net/disk_cache/stats_histogram.cc
@@ -0,0 +1,89 @@
+// Copyright (c) 2012 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 "net/disk_cache/stats_histogram.h"
+
+#include "base/debug/leak_annotations.h"
+#include "base/logging.h"
+#include "base/metrics/bucket_ranges.h"
+#include "base/metrics/histogram_base.h"
+#include "base/metrics/sample_vector.h"
+#include "base/metrics/statistics_recorder.h"
+#include "net/disk_cache/stats.h"
+
+namespace disk_cache {
+
+using base::BucketRanges;
+using base::Histogram;
+using base::HistogramSamples;
+using base::SampleVector;
+using base::StatisticsRecorder;
+
+StatsHistogram::StatsHistogram(const std::string& name,
+                               Sample minimum,
+                               Sample maximum,
+                               const BucketRanges* ranges,
+                               const Stats* stats)
+    : Histogram(name, minimum, maximum, ranges),
+      stats_(stats) {}
+
+StatsHistogram::~StatsHistogram() {}
+
+// static
+void StatsHistogram::InitializeBucketRanges(const Stats* stats,
+                                            BucketRanges* ranges) {
+  for (size_t i = 0; i < ranges->size(); ++i) {
+    ranges->set_range(i, stats->GetBucketRange(i));
+  }
+  ranges->ResetChecksum();
+}
+
+StatsHistogram* StatsHistogram::FactoryGet(const std::string& name,
+                                           const Stats* stats) {
+  Sample minimum = 1;
+  Sample maximum = disk_cache::Stats::kDataSizesLength - 1;
+  size_t bucket_count = disk_cache::Stats::kDataSizesLength;
+  HistogramBase* histogram = StatisticsRecorder::FindHistogram(name);
+  if (!histogram) {
+    DCHECK(stats);
+
+    // To avoid racy destruction at shutdown, the following will be leaked.
+    BucketRanges* ranges = new BucketRanges(bucket_count + 1);
+    InitializeBucketRanges(stats, ranges);
+    const BucketRanges* registered_ranges =
+        StatisticsRecorder::RegisterOrDeleteDuplicateRanges(ranges);
+
+    // To avoid racy destruction at shutdown, the following will be leaked.
+    StatsHistogram* stats_histogram =
+        new StatsHistogram(name, minimum, maximum, registered_ranges, stats);
+    stats_histogram->SetFlags(kUmaTargetedHistogramFlag);
+    histogram = StatisticsRecorder::RegisterOrDeleteDuplicate(stats_histogram);
+  }
+
+  DCHECK(base::HISTOGRAM == histogram->GetHistogramType());
+  DCHECK(histogram->HasConstructionArguments(minimum, maximum, bucket_count));
+
+  // We're preparing for an otherwise unsafe upcast by ensuring we have the
+  // proper class type.
+  StatsHistogram* return_histogram = static_cast<StatsHistogram*>(histogram);
+  return return_histogram;
+}
+
+scoped_ptr<HistogramSamples> StatsHistogram::SnapshotSamples() const {
+  scoped_ptr<SampleVector> samples(new SampleVector(bucket_ranges()));
+  stats_->Snapshot(samples.get());
+
+  // Only report UMA data once.
+  StatsHistogram* mutable_me = const_cast<StatsHistogram*>(this);
+  mutable_me->ClearFlags(kUmaTargetedHistogramFlag);
+
+  return samples.PassAs<HistogramSamples>();
+}
+
+int StatsHistogram::FindCorruption(const HistogramSamples& samples) const {
+  // This class won't monitor inconsistencies.
+  return HistogramBase::NO_INCONSISTENCIES;
+}
+
+}  // namespace disk_cache