Create new directory for budget_service

chrome/browser/push_messaging/background_budget_service.cc

-// Copyright 2016 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 "chrome/browser/push_messaging/background_budget_service.h"
-
-#include <stdint.h>
-
-#include "base/callback.h"
-#include "base/memory/ptr_util.h"
-#include "base/metrics/histogram_macros.h"
-#include "base/strings/string_number_conversions.h"
-#include "base/strings/string_split.h"
-#include "base/strings/stringprintf.h"
-#include "base/time/clock.h"
-#include "base/time/default_clock.h"
-#include "base/time/time.h"
-#include "chrome/browser/engagement/site_engagement_score.h"
-#include "chrome/browser/engagement/site_engagement_service.h"
-#include "chrome/browser/profiles/profile.h"
-#include "chrome/common/pref_names.h"
-#include "components/pref_registry/pref_registry_syncable.h"
-#include "components/prefs/pref_service.h"
-#include "components/prefs/scoped_user_pref_update.h"
-
-namespace {
-
-constexpr char kSeparator = '#';
-
-// Calculate the ratio of the different components of a budget with respect
-// to a maximum time period of 10 days = 864000.0 seconds.
-constexpr double kSecondsToAccumulate = 864000.0;
-
-bool GetBudgetDataFromPrefs(Profile* profile,
-                            const GURL& origin,
-                            double* old_budget,
-                            double* old_ses,
-                            double* last_updated) {
-  const base::DictionaryValue* map =
-      profile->GetPrefs()->GetDictionary(prefs::kBackgroundBudgetMap);
-
-  std::string map_string;
-  map->GetStringWithoutPathExpansion(origin.spec(), &map_string);
-
-  // There is no data for the preference, return false and let the caller
-  // deal with that.
-  if (map_string.empty())
-    return false;
-
-  std::vector<base::StringPiece> parts =
-      base::SplitStringPiece(map_string, base::StringPiece(&kSeparator, 1),
-                             base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL);
-  if ((parts.size() != 3) ||
-      (!base::StringToDouble(parts[0].as_string(), last_updated)) ||
-      (!base::StringToDouble(parts[1].as_string(), old_budget)) ||
-      (!base::StringToDouble(parts[2].as_string(), old_ses))) {
-    // Somehow the data stored in the preferences has become corrupted, log an
-    // error and remove the invalid data.
-    LOG(ERROR) << "Preferences data for background budget service is "
-               << "invalid for origin " << origin.possibly_invalid_spec();
-    DictionaryPrefUpdate update(profile->GetPrefs(),
-                                prefs::kBackgroundBudgetMap);
-    base::DictionaryValue* update_map = update.Get();
-    update_map->RemoveWithoutPathExpansion(origin.spec(), nullptr);
-    return false;
-  }
-
-  return true;
-}
-
-// The value stored in prefs is a concatenated string of last updated time, old
-// budget, and old ses.
-void SetBudgetDataInPrefs(Profile* profile,
-                          const GURL& origin,
-                          double last_updated,
-                          double budget,
-                          double ses) {
-  std::string s = base::StringPrintf("%f%c%f%c%f", last_updated, kSeparator,
-                                     budget, kSeparator, ses);
-  DictionaryPrefUpdate update(profile->GetPrefs(), prefs::kBackgroundBudgetMap);
-  base::DictionaryValue* map = update.Get();
-
-  map->SetStringWithoutPathExpansion(origin.spec(), s);
-}
-
-}  // namespace
-
-BackgroundBudgetService::BackgroundBudgetService(Profile* profile)
-    : clock_(base::WrapUnique(new base::DefaultClock)), profile_(profile) {
-  DCHECK(profile);
-}
-
-BackgroundBudgetService::~BackgroundBudgetService() {}
-
-// static
-void BackgroundBudgetService::RegisterProfilePrefs(
-    user_prefs::PrefRegistrySyncable* registry) {
-  registry->RegisterDictionaryPref(prefs::kBackgroundBudgetMap);
-}
-
-// static
-double BackgroundBudgetService::GetCost(CostType type) {
-  switch (type) {
-    case CostType::SILENT_PUSH:
-      return 2.0;
-      // No default case.
-  }
-  NOTREACHED();
-  return SiteEngagementScore::kMaxPoints + 1.0;
-}
-
-double BackgroundBudgetService::GetBudget(const GURL& origin) {
-  DCHECK_EQ(origin, origin.GetOrigin());
-
-  // Get the current SES score, which we'll use to set a new budget.
-  SiteEngagementService* service = SiteEngagementService::Get(profile_);
-  double ses_score = service->GetScore(origin);
-
-  // Get the last used budget data. This is a triple of last calculated time,
-  // budget at that time, and Site Engagement Score (ses) at that time.
-  double old_budget = 0.0, old_ses = 0.0, last_updated_msec = 0.0;
-  if (!GetBudgetDataFromPrefs(profile_, origin, &old_budget, &old_ses,
-                              &last_updated_msec)) {
-    // If there is no stored data or the data can't be parsed, just return the
-    // SES.
-    return ses_score;
-  }
-
-  base::Time now = clock_->Now();
-  base::TimeDelta elapsed = now - base::Time::FromDoubleT(last_updated_msec);
-
-  // The user can set their clock backwards, so if the last updated time is in
-  // the future, don't update the budget based on elapsed time. Eventually the
-  // clock will reach the future, and the budget calculations will catch up.
-  // TODO(harkness): Consider what to do if the clock jumps forward by a
-  // significant amount.
-  if (elapsed.InMicroseconds() < 0)
-    return old_budget;
-
-  // For each time period that elapses, calculate the carryover ratio as the
-  // ratio of time remaining in our max period to the total period.
-  // The carryover component is then the old budget multiplied by the ratio.
-  double carryover_ratio = std::max(
-      0.0,
-      ((kSecondsToAccumulate - elapsed.InSeconds()) / kSecondsToAccumulate));
-  double budget_carryover = old_budget * carryover_ratio;
-
-  // The ses component is an average of the last ses score used for budget
-  // calculation and the current ses score.
-  // The ses average is them multiplied by the ratio of time elapsed to the
-  // total period.
-  double ses_ratio =
-      std::min(1.0, (elapsed.InSeconds() / kSecondsToAccumulate));
-  double ses_component = (old_ses + ses_score) / 2 * ses_ratio;
-
-  // Budget recalculation consists of a budget carryover component, which
-  // rewards sites that don't use all their budgets every day, and a ses
-  // component, which gives extra budget to sites that have a high ses score.
-  double budget = budget_carryover + ses_component;
-  DCHECK_GE(budget, 0.0);
-
-  return budget;
-}
-
-void BackgroundBudgetService::StoreBudget(const GURL& origin, double budget) {
-  DCHECK_EQ(origin, origin.GetOrigin());
-  DCHECK_GE(budget, 0.0);
-  DCHECK_LE(budget, SiteEngagementService::GetMaxPoints());
-
-  // Get the current SES score to write into the prefs with the new budget.
-  SiteEngagementService* service = SiteEngagementService::Get(profile_);
-  double ses_score = service->GetScore(origin);
-
-  base::Time time = clock_->Now();
-  SetBudgetDataInPrefs(profile_, origin, time.ToDoubleT(), budget, ses_score);
-}
-
-// Override the default clock with the specified clock. Only used for testing.
-void BackgroundBudgetService::SetClockForTesting(
-    std::unique_ptr<base::Clock> clock) {
-  clock_ = std::move(clock);
-}