blob: b9101e8334172f00b928fb27e9cd0a6744f739a6 [file] [log] [blame]
// Copyright 2020 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 "components/metrics/date_changed_helper.h"
#include "base/time/time.h"
#include "components/prefs/pref_registry_simple.h"
#include "components/prefs/pref_service.h"
namespace metrics {
namespace {
base::Time GetCurrentDate(base::Time now) {
// Use local midnight to ensure reporting is for calendar days, not UTC, and
// avoid storing extra information about when this was called.
return now.LocalMidnight();
void UpdateStoredDate(PrefService* prefs,
const char* pref_name,
base::Time now) {
prefs->SetTime(pref_name, GetCurrentDate(now));
bool IsStoredDateToday(PrefService* prefs,
const char* pref_name,
base::Time now) {
base::Time stored_date = prefs->GetTime(pref_name);
if (stored_date.is_null()) {
// Consider date unchanged if pref has never been set.
UpdateStoredDate(prefs, pref_name, GetCurrentDate(now));
return true;
// Ignore small changes in midnight such as time zone changes.
return std::abs((stored_date - GetCurrentDate(now)).InHours()) < 12;
} // namespace
namespace date_changed_helper {
bool HasDateChangedSinceLastCall(PrefService* prefs, const char* pref_name) {
base::Time now = base::Time::Now();
if (IsStoredDateToday(prefs, pref_name, now))
return false;
UpdateStoredDate(prefs, pref_name, now);
return true;
void RegisterPref(PrefRegistrySimple* registry, const char* pref_name) {
registry->RegisterTimePref(pref_name, base::Time());
} // namespace date_changed_helper
} // namespace metrics