chrome/browser/engagement/site_engagement_eviction_policy.cc

   1 // Copyright 2015 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "base/barrier_closure.h"
   6 #include "chrome/browser/browser_process.h"
   7 #include "chrome/browser/engagement/site_engagement_eviction_policy.h"
   8 #include "chrome/browser/engagement/site_engagement_service.h"
   9 #include "chrome/browser/profiles/profile.h"
  10 #include "chrome/browser/profiles/profile_manager.h"
  11 #include "content/public/browser/browser_thread.h"
  12
  13 namespace {
  14
  15 const int kExpectedEngagementSites = 200;
  16
  17 // Gets the quota that an origin deserves based on its site engagement.
  18 int64 GetSoftQuotaForOrigin(const GURL& origin,
  19                             int score,
  20                             int total_engagement_points,
  21                             int64 global_quota) {
  22   double quota_per_point =
  23       global_quota /
  24       std::max(kExpectedEngagementSites * SiteEngagementScore::kMaxPoints,
  25                static_cast<double>(total_engagement_points));
  26
  27   return score * quota_per_point;
  28 }
  29
  30 GURL DoCalculateEvictionOrigin(
  31     const scoped_refptr<storage::SpecialStoragePolicy>& special_storage_policy,
  32     SiteEngagementScoreProvider* score_provider,
  33     const std::map<GURL, int64>& usage_map,
  34     int64 global_quota) {
  35   // TODO(calamity): Integrate storage access frequency as an input to this
  36   // heuristic.
  37
  38   // This heuristic is intended to optimize for two criteria:
  39   // - evict the site that the user cares about least
  40   // - evict the least number of sites to get under the quota limit
  41   //
  42   // The heuristic for deciding the next eviction origin calculates a soft
  43   // quota for each origin which is the amount the origin should be allowed to
  44   // use based on its engagement and the global quota. The origin that most
  45   // exceeds its soft quota is chosen.
  46   GURL origin_to_evict;
  47   int64 max_overuse = std::numeric_limits<int64>::min();
  48   int total_engagement_points = score_provider->GetTotalEngagementPoints();
  49
  50   for (const auto& usage : usage_map) {
  51     GURL origin = usage.first;
  52     if (special_storage_policy &&
  53         (special_storage_policy->IsStorageUnlimited(origin) ||
  54          special_storage_policy->IsStorageDurable(origin))) {
  55       continue;
  56     }
  57
  58     // |overuse| can be negative if the soft quota exceeds the usage.
  59     int64 overuse = usage.second - GetSoftQuotaForOrigin(
  60                                        origin, score_provider->GetScore(origin),
  61                                        total_engagement_points, global_quota);
  62     if (overuse > max_overuse) {
  63       max_overuse = overuse;
  64       origin_to_evict = origin;
  65     }
  66   }
  67   return origin_to_evict;
  68 }
  69
  70 GURL GetSiteEngagementEvictionOriginOnUIThread(
  71     const scoped_refptr<storage::SpecialStoragePolicy>& special_storage_policy,
  72     content::BrowserContext* browser_context,
  73     const std::map<GURL, int64>& usage_map,
  74     int64 global_quota) {
  75   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
  76   Profile* profile = Profile::FromBrowserContext(browser_context);
  77   SiteEngagementService* service =
  78       g_browser_process->profile_manager()->IsValidProfile(profile)
  79           ? SiteEngagementService::Get(profile)
  80           : nullptr;
  81   if (!service)
  82     return GURL();
  83
  84   return DoCalculateEvictionOrigin(special_storage_policy, service, usage_map,
  85                                    global_quota);
  86 }
  87
  88 }  // namespace
  89
  90 SiteEngagementEvictionPolicy::SiteEngagementEvictionPolicy(
  91     content::BrowserContext* browser_context)
  92     : browser_context_(browser_context) {}
  93
  94 SiteEngagementEvictionPolicy::~SiteEngagementEvictionPolicy() {}
  95
  96 void SiteEngagementEvictionPolicy::GetEvictionOrigin(
  97     const scoped_refptr<storage::SpecialStoragePolicy>& special_storage_policy,
  98     const std::map<GURL, int64>& usage_map,
  99     int64 global_quota,
 100     const storage::GetOriginCallback& callback) {
 101   content::BrowserThread::PostTaskAndReplyWithResult(
 102       content::BrowserThread::UI, FROM_HERE,
 103       base::Bind(&GetSiteEngagementEvictionOriginOnUIThread,
 104                  special_storage_policy, browser_context_, usage_map,
 105                  global_quota),
 106       callback);
 107 }
 108
 109 // static
 110 GURL SiteEngagementEvictionPolicy::CalculateEvictionOrigin(
 111     const scoped_refptr<storage::SpecialStoragePolicy>& special_storage_policy,
 112     SiteEngagementScoreProvider* score_provider,
 113     const std::map<GURL, int64>& usage_map,
 114     int64 global_quota) {
 115   return DoCalculateEvictionOrigin(special_storage_policy, score_provider,
 116                                    usage_map, global_quota);
 117 }