// Copyright (c) 2008 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/logging.h"
#include "net/disk_cache/stats.h"
namespace disk_cache {
// Static.
const Stats* StatsHistogram::stats_ = NULL;
scoped_refptr<StatsHistogram> StatsHistogram::StatsHistogramFactoryGet(
const std::string& name) {
scoped_refptr<Histogram> histogram(NULL);
Sample minimum = 1;
Sample maximum = disk_cache::Stats::kDataSizesLength - 1;
size_t bucket_count = disk_cache::Stats::kDataSizesLength;
if (StatisticsRecorder::FindHistogram(name, &histogram)) {
DCHECK(histogram.get() != NULL);
} else {
histogram = new StatsHistogram(name, minimum, maximum, bucket_count);
scoped_refptr<Histogram> registered_histogram(NULL);
StatisticsRecorder::FindHistogram(name, ®istered_histogram);
if (registered_histogram.get() != NULL &&
registered_histogram.get() != histogram.get())
histogram = registered_histogram;
}
DCHECK(HISTOGRAM == histogram->histogram_type());
DCHECK(histogram->HasConstructorArguments(minimum, maximum, bucket_count));
// We're preparing for an otherwise unsafe upcast by ensuring we have the
// proper class type.
Histogram* temp_histogram = histogram.get();
StatsHistogram* temp_stats_histogram =
static_cast<StatsHistogram*>(temp_histogram);
scoped_refptr<StatsHistogram> return_histogram = temp_stats_histogram;
return return_histogram;
}
bool StatsHistogram::Init(const Stats* stats) {
DCHECK(stats);
if (stats_)
return false;
SetFlags(kUmaTargetedHistogramFlag);
// We support statistics report for only one cache.
init_ = true;
stats_ = stats;
return true;
}
StatsHistogram::~StatsHistogram() {
// Only cleanup what we set.
if (init_)
stats_ = NULL;
}
Histogram::Sample StatsHistogram::ranges(size_t i) const {
DCHECK(stats_);
return stats_->GetBucketRange(i);
}
size_t StatsHistogram::bucket_count() const {
return disk_cache::Stats::kDataSizesLength;
}
void StatsHistogram::SnapshotSample(SampleSet* sample) const {
DCHECK(stats_);
StatsSamples my_sample;
stats_->Snapshot(&my_sample);
*sample = my_sample;
// Only report UMA data once.
StatsHistogram* mutable_me = const_cast<StatsHistogram*>(this);
mutable_me->ClearFlags(kUmaTargetedHistogramFlag);
}
} // namespace disk_cache