Change how the quota system computes the total poolsize for temporary storage

chrome/browser/engagement/site_engagement_eviction_policy.cc

-// Copyright 2015 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/engagement/site_engagement_eviction_policy.h"
-
-#include "base/command_line.h"
-#include "base/metrics/field_trial.h"
-#include "base/strings/string_util.h"
-#include "chrome/browser/browser_process.h"
-#include "chrome/browser/engagement/site_engagement_service.h"
-#include "chrome/browser/profiles/profile.h"
-#include "chrome/browser/profiles/profile_manager.h"
-#include "chrome/common/chrome_switches.h"
-#include "content/public/browser/browser_thread.h"
-
-namespace {
-
-const int kExpectedEngagementSites = 200;
-
-// Gets the quota that an origin deserves based on its site engagement.
-int64_t GetSoftQuotaForOrigin(const GURL& origin,
-                              int score,
-                              int total_engagement_points,
-                              int64_t global_quota) {
-  double quota_per_point =
-      global_quota /
-      std::max(kExpectedEngagementSites * SiteEngagementService::GetMaxPoints(),
-               static_cast<double>(total_engagement_points));
-
-  return score * quota_per_point;
-}
-
-GURL DoCalculateEvictionOrigin(
-    const scoped_refptr<storage::SpecialStoragePolicy>& special_storage_policy,
-    SiteEngagementScoreProvider* score_provider,
-    const std::set<GURL>& exceptions,
-    const std::map<GURL, int64_t>& usage_map,
-    int64_t global_quota) {
-  // TODO(calamity): Integrate storage access frequency as an input to this
-  // heuristic.
-
-  // This heuristic is intended to optimize for two criteria:
-  // - evict the site that the user cares about least
-  // - evict the least number of sites to get under the quota limit
-  //
-  // The heuristic for deciding the next eviction origin calculates a soft
-  // quota for each origin which is the amount the origin should be allowed to
-  // use based on its engagement and the global quota. The origin that most
-  // exceeds its soft quota is chosen.
-  GURL origin_to_evict;
-  int64_t max_overuse = std::numeric_limits<int64_t>::min();
-  int total_engagement_points = score_provider->GetTotalEngagementPoints();
-
-  for (const auto& usage : usage_map) {
-    GURL origin = usage.first;
-    if (special_storage_policy &&
-        (special_storage_policy->IsStorageUnlimited(origin) ||
-         special_storage_policy->IsStorageDurable(origin))) {
-      continue;
-    }
-
-    // |overuse| can be negative if the soft quota exceeds the usage.
-    int64_t overuse =
-        usage.second -
-        GetSoftQuotaForOrigin(origin, score_provider->GetScore(origin),
-                              total_engagement_points, global_quota);
-    if (overuse > max_overuse && !base::ContainsKey(exceptions, origin)) {
-      max_overuse = overuse;
-      origin_to_evict = origin;
-    }
-  }
-
-  return origin_to_evict;
-}
-
-GURL GetSiteEngagementEvictionOriginOnUIThread(
-    const scoped_refptr<storage::SpecialStoragePolicy>& special_storage_policy,
-    content::BrowserContext* browser_context,
-    const std::set<GURL>& exceptions,
-    const std::map<GURL, int64_t>& usage_map,
-    int64_t global_quota) {
-  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
-
-  Profile* profile = Profile::FromBrowserContext(browser_context);
-  SiteEngagementScoreProvider* score_provider =
-      g_browser_process->profile_manager()->IsValidProfile(profile)
-          ? SiteEngagementService::Get(profile)
-          : nullptr;
-
-  if (!score_provider)
-    return GURL();
-
-  return DoCalculateEvictionOrigin(special_storage_policy, score_provider,
-                                   exceptions, usage_map, global_quota);
-}
-
-}  // namespace
-
-// static
-bool SiteEngagementEvictionPolicy::IsEnabled() {
-  if (base::CommandLine::ForCurrentProcess()->HasSwitch(
-      switches::kEnableSiteEngagementEvictionPolicy)) {
-    return true;
-  }
-
-  const std::string group_name = base::FieldTrialList::FindFullName(
-      SiteEngagementService::kEngagementParams);
-  return base::StartsWith(group_name, "StorageEvictionEnabled",
-                          base::CompareCase::SENSITIVE);
-}
-
-SiteEngagementEvictionPolicy::SiteEngagementEvictionPolicy(
-    content::BrowserContext* browser_context)
-    : browser_context_(browser_context) {}
-
-SiteEngagementEvictionPolicy::~SiteEngagementEvictionPolicy() {}
-
-void SiteEngagementEvictionPolicy::GetEvictionOrigin(
-    const scoped_refptr<storage::SpecialStoragePolicy>& special_storage_policy,
-    const std::set<GURL>& exceptions,
-    const std::map<GURL, int64_t>& usage_map,
-    int64_t global_quota,
-    const storage::GetOriginCallback& callback) {
-  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
-
-  content::BrowserThread::PostTaskAndReplyWithResult(
-      content::BrowserThread::UI, FROM_HERE,
-      base::Bind(&GetSiteEngagementEvictionOriginOnUIThread,
-                 special_storage_policy, browser_context_, exceptions,
-                 usage_map, global_quota),
-      callback);
-}
-
-// static
-GURL SiteEngagementEvictionPolicy::CalculateEvictionOriginForTests(
-    const scoped_refptr<storage::SpecialStoragePolicy>& special_storage_policy,
-    SiteEngagementScoreProvider* score_provider,
-    const std::set<GURL>& exceptions,
-    const std::map<GURL, int64_t>& usage_map,
-    int64_t global_quota) {
-  return DoCalculateEvictionOrigin(special_storage_policy, score_provider,
-                                   exceptions, usage_map, global_quota);
-}