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// Copyright 2020 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "chrome/browser/preloading/prefetch/prefetch_service/prefetch_origin_decider.h"
#include <memory>
#include <vector>
#include "base/json/values_util.h"
#include "base/metrics/histogram_macros.h"
#include "base/time/time.h"
#include "chrome/browser/prefetch/pref_names.h"
#include "components/prefs/pref_registry_simple.h"
#include "components/prefs/pref_service.h"
// static
void PrefetchOriginDecider::RegisterPrefs(PrefRegistrySimple* registry) {
// Some loss in this pref (especially following a browser crash) is well
// tolerated and helps ensure the pref service isn't slammed.
registry->RegisterDictionaryPref(prefetch::prefs::kRetryAfterPrefPath,
PrefRegistry::LOSSY_PREF);
}
PrefetchOriginDecider::PrefetchOriginDecider(PrefService* pref_service,
base::Clock* clock)
: pref_service_(pref_service), clock_(clock) {
DCHECK(pref_service);
DCHECK(clock);
LoadFromPrefs();
if (ClearPastEntries()) {
SaveToPrefs();
}
}
PrefetchOriginDecider::~PrefetchOriginDecider() = default;
void PrefetchOriginDecider::OnBrowsingDataCleared() {
origin_retry_afters_.clear();
SaveToPrefs();
}
bool PrefetchOriginDecider::IsOriginOutsideRetryAfterWindow(
const GURL& url) const {
url::Origin origin = url::Origin::Create(url);
auto iter = origin_retry_afters_.find(origin);
if (iter == origin_retry_afters_.end()) {
return true;
}
return iter->second < clock_->Now();
}
void PrefetchOriginDecider::ReportOriginRetryAfter(
const GURL& url,
base::TimeDelta retry_after) {
// Ignore negative times.
if (retry_after.is_negative()) {
return;
}
UMA_HISTOGRAM_CUSTOM_TIMES("PrefetchProxy.Prefetch.Mainframe.RetryAfter",
retry_after, base::Seconds(1), base::Days(7), 100);
origin_retry_afters_.emplace(url::Origin::Create(url),
clock_->Now() + retry_after);
SaveToPrefs();
}
void PrefetchOriginDecider::LoadFromPrefs() {
origin_retry_afters_.clear();
const base::Value::Dict& dictionary =
pref_service_->GetDict(prefetch::prefs::kRetryAfterPrefPath);
for (auto element : dictionary) {
GURL url_origin(element.first);
if (!url_origin.is_valid()) {
// This may happen in the case of corrupted prefs, or otherwise. Handle
// gracefully.
NOTREACHED();
}
std::optional<base::Time> retry_after = base::ValueToTime(element.second);
if (!retry_after) {
// This may happen in the case of corrupted prefs, or otherwise. Handle
// gracefully.
NOTREACHED();
}
url::Origin origin = url::Origin::Create(url_origin);
origin_retry_afters_.emplace(origin, retry_after.value());
}
}
void PrefetchOriginDecider::SaveToPrefs() const {
base::Value::Dict dictionary;
for (const auto& element : origin_retry_afters_) {
std::string key = element.first.GetURL().spec();
base::Value value = base::TimeToValue(element.second);
dictionary.Set(std::move(key), std::move(value));
}
pref_service_->SetDict(prefetch::prefs::kRetryAfterPrefPath,
std::move(dictionary));
}
bool PrefetchOriginDecider::ClearPastEntries() {
std::vector<url::Origin> to_remove;
for (const auto& entry : origin_retry_afters_) {
if (entry.second < clock_->Now()) {
to_remove.push_back(entry.first);
}
}
if (to_remove.empty()) {
return false;
}
for (const auto& rm : to_remove) {
origin_retry_afters_.erase(rm);
}
return true;
}
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