blob: 943990a3b4a7ffe8112391604102ad665dc2572b [file] [log] [blame]
// Copyright (c) 2011 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 "net/disk_cache/stats.h"
namespace disk_cache {
using base::Histogram;
using base::StatisticsRecorder;
// Static.
const Stats* StatsHistogram::stats_ = NULL;
StatsHistogram::~StatsHistogram() {
// Only cleanup what we set.
if (init_)
stats_ = NULL;
StatsHistogram* StatsHistogram::FactoryGet(const std::string& name) {
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 != NULL);
} else {
// To avoid racy destruction at shutdown, the following will be leaked.
StatsHistogram* stats_histogram =
new StatsHistogram(name, minimum, maximum, bucket_count);
histogram = StatisticsRecorder::RegisterOrDeleteDuplicate(stats_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.
StatsHistogram* return_histogram = static_cast<StatsHistogram*>(histogram);
// Validate upcast by seeing that we're probably providing the checksum.
return return_histogram;
bool StatsHistogram::Init(const Stats* stats) {
if (stats_)
return false;
// We support statistics report for only one cache.
init_ = true;
stats_ = stats;
return true;
Histogram::Sample StatsHistogram::ranges(size_t i) const {
return stats_->GetBucketRange(i);
size_t StatsHistogram::bucket_count() const {
return disk_cache::Stats::kDataSizesLength;
void StatsHistogram::SnapshotSample(SampleSet* sample) const {
StatsSamples my_sample;
*sample = my_sample;
// Only report UMA data once.
StatsHistogram* mutable_me = const_cast<StatsHistogram*>(this);
Histogram::Inconsistencies StatsHistogram::FindCorruption(
const SampleSet& snapshot) const {
return NO_INCONSISTENCIES; // This class won't monitor inconsistencies.
uint32 StatsHistogram::CalculateRangeChecksum() const {
// We don't calculate checksums, so at least establish a unique constant.
const uint32 kStatsHistogramChecksum = 0x0cecce;
return kStatsHistogramChecksum;
} // namespace disk_cache