chrome/browser/apps/ephemeral_app_service.cc

   1 // Copyright 2013 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 "chrome/browser/apps/ephemeral_app_service.h"
   6
   7 #include "base/command_line.h"
   8 #include "chrome/browser/apps/ephemeral_app_service_factory.h"
   9 #include "chrome/browser/chrome_notification_types.h"
  10 #include "chrome/browser/extensions/data_deleter.h"
  11 #include "chrome/browser/extensions/extension_service.h"
  12 #include "chrome/browser/extensions/extension_util.h"
  13 #include "chrome/browser/profiles/profile.h"
  14 #include "chrome/common/chrome_switches.h"
  15 #include "content/public/browser/notification_service.h"
  16 #include "content/public/browser/notification_source.h"
  17 #include "content/public/browser/notification_types.h"
  18 #include "extensions/browser/extension_prefs.h"
  19 #include "extensions/browser/extension_registry.h"
  20 #include "extensions/browser/extension_system.h"
  21 #include "extensions/common/extension.h"
  22 #include "extensions/common/extension_set.h"
  23
  24 using extensions::Extension;
  25 using extensions::ExtensionInfo;
  26 using extensions::ExtensionPrefs;
  27 using extensions::ExtensionSet;
  28 using extensions::ExtensionSystem;
  29 using extensions::InstalledExtensionInfo;
  30
  31 namespace {
  32
  33 // The number of seconds after startup before performing garbage collection
  34 // of ephemeral apps.
  35 const int kGarbageCollectAppsStartupDelay = 60;
  36
  37 // The number of seconds after an ephemeral app has been installed before
  38 // performing garbage collection.
  39 const int kGarbageCollectAppsInstallDelay = 15;
  40
  41 // When the number of ephemeral apps reaches this count, trigger garbage
  42 // collection to trim off the least-recently used apps in excess of
  43 // kMaxEphemeralAppsCount.
  44 const int kGarbageCollectAppsTriggerCount = 35;
  45
  46 // The number of seconds after startup before performing garbage collection
  47 // of the data of evicted ephemeral apps.
  48 const int kGarbageCollectDataStartupDelay = 120;
  49
  50 }  // namespace
  51
  52 const int EphemeralAppService::kAppInactiveThreshold = 10;
  53 const int EphemeralAppService::kAppKeepThreshold = 1;
  54 const int EphemeralAppService::kMaxEphemeralAppsCount = 30;
  55 const int EphemeralAppService::kDataInactiveThreshold = 90;
  56
  57 // static
  58 EphemeralAppService* EphemeralAppService::Get(Profile* profile) {
  59   return EphemeralAppServiceFactory::GetForProfile(profile);
  60 }
  61
  62 EphemeralAppService::EphemeralAppService(Profile* profile)
  63     : profile_(profile),
  64       ephemeral_app_count_(-1) {
  65   if (!CommandLine::ForCurrentProcess()->HasSwitch(
  66             switches::kEnableEphemeralApps))
  67     return;
  68
  69   registrar_.Add(this, chrome::NOTIFICATION_EXTENSION_INSTALLED,
  70                  content::Source<Profile>(profile_));
  71   registrar_.Add(this, chrome::NOTIFICATION_EXTENSION_UNINSTALLED,
  72                  content::Source<Profile>(profile_));
  73   registrar_.Add(this, chrome::NOTIFICATION_EXTENSIONS_READY,
  74                  content::Source<Profile>(profile_));
  75   registrar_.Add(this, chrome::NOTIFICATION_PROFILE_DESTROYED,
  76                  content::Source<Profile>(profile_));
  77 }
  78
  79 EphemeralAppService::~EphemeralAppService() {
  80 }
  81
  82 void EphemeralAppService::Observe(
  83     int type,
  84     const content::NotificationSource& source,
  85     const content::NotificationDetails& details) {
  86   switch (type) {
  87     case chrome::NOTIFICATION_EXTENSIONS_READY: {
  88       Init();
  89       break;
  90     }
  91     case chrome::NOTIFICATION_EXTENSION_INSTALLED: {
  92       const Extension* extension =
  93           content::Details<const InstalledExtensionInfo>(details)->extension;
  94       DCHECK(extension);
  95       if (extension->is_ephemeral()) {
  96         ++ephemeral_app_count_;
  97         if (ephemeral_app_count_ >= kGarbageCollectAppsTriggerCount)
  98           TriggerGarbageCollect(
  99               base::TimeDelta::FromSeconds(kGarbageCollectAppsInstallDelay));
 100       }
 101       break;
 102     }
 103     case chrome::NOTIFICATION_EXTENSION_UNINSTALLED: {
 104       const Extension* extension =
 105           content::Details<const Extension>(details).ptr();
 106       DCHECK(extension);
 107       if (extension->is_ephemeral())
 108         --ephemeral_app_count_;
 109       break;
 110     }
 111     case chrome::NOTIFICATION_PROFILE_DESTROYED: {
 112       // Ideally we need to know when the extension system is shutting down.
 113       garbage_collect_apps_timer_.Stop();
 114       break;
 115     }
 116     default:
 117       NOTREACHED();
 118   };
 119 }
 120
 121 void EphemeralAppService::Init() {
 122   InitEphemeralAppCount();
 123   TriggerGarbageCollect(
 124       base::TimeDelta::FromSeconds(kGarbageCollectAppsStartupDelay));
 125
 126   garbage_collect_data_timer_.Start(
 127       FROM_HERE,
 128       base::TimeDelta::FromSeconds(kGarbageCollectDataStartupDelay),
 129       this,
 130       &EphemeralAppService::GarbageCollectData);
 131 }
 132
 133 void EphemeralAppService::InitEphemeralAppCount() {
 134   scoped_ptr<ExtensionSet> extensions =
 135       extensions::ExtensionRegistry::Get(profile_)
 136           ->GenerateInstalledExtensionsSet();
 137
 138   ephemeral_app_count_ = 0;
 139   for (ExtensionSet::const_iterator it = extensions->begin();
 140        it != extensions->end(); ++it) {
 141     const Extension* extension = *it;
 142     if (extension->is_ephemeral())
 143       ++ephemeral_app_count_;
 144   }
 145 }
 146
 147 void EphemeralAppService::TriggerGarbageCollect(const base::TimeDelta& delay) {
 148   if (!garbage_collect_apps_timer_.IsRunning()) {
 149     garbage_collect_apps_timer_.Start(
 150         FROM_HERE,
 151         delay,
 152         this,
 153         &EphemeralAppService::GarbageCollectApps);
 154   }
 155 }
 156
 157 void EphemeralAppService::GarbageCollectApps() {
 158   scoped_ptr<ExtensionSet> extensions =
 159       extensions::ExtensionRegistry::Get(profile_)
 160           ->GenerateInstalledExtensionsSet();
 161   ExtensionPrefs* prefs = ExtensionPrefs::Get(profile_);
 162
 163   int app_count = 0;
 164   LaunchTimeAppMap app_launch_times;
 165   std::set<std::string> remove_app_ids;
 166
 167   // Populate a list of ephemeral apps, ordered by their last launch time.
 168   for (ExtensionSet::const_iterator it = extensions->begin();
 169        it != extensions->end(); ++it) {
 170     const Extension* extension = *it;
 171     if (!extension->is_ephemeral())
 172       continue;
 173
 174     ++app_count;
 175
 176     // Do not remove ephemeral apps that are running.
 177     if (!extensions::util::IsExtensionIdle(extension->id(), profile_))
 178       continue;
 179
 180     base::Time last_launch_time = prefs->GetLastLaunchTime(extension->id());
 181
 182     // If the last launch time is invalid, this may be because it was just
 183     // installed. So use the install time. If this is also null for some reason,
 184     // the app will be removed.
 185     if (last_launch_time.is_null())
 186       last_launch_time = prefs->GetInstallTime(extension->id());
 187
 188     app_launch_times.insert(std::make_pair(last_launch_time, extension->id()));
 189   }
 190
 191   ExtensionService* service =
 192       ExtensionSystem::Get(profile_)->extension_service();
 193   DCHECK(service);
 194   // Execute the replacement policies and remove apps marked for deletion.
 195   if (!app_launch_times.empty()) {
 196     GetAppsToRemove(app_count, app_launch_times, &remove_app_ids);
 197     for (std::set<std::string>::const_iterator id = remove_app_ids.begin();
 198          id != remove_app_ids.end(); ++id) {
 199       if (service->UninstallExtension(*id, false, NULL))
 200         --app_count;
 201     }
 202   }
 203
 204   ephemeral_app_count_ = app_count;
 205 }
 206
 207 // static
 208 void EphemeralAppService::GetAppsToRemove(
 209     int app_count,
 210     const LaunchTimeAppMap& app_launch_times,
 211     std::set<std::string>* remove_app_ids) {
 212   base::Time time_now = base::Time::Now();
 213   const base::Time inactive_threshold =
 214       time_now - base::TimeDelta::FromDays(kAppInactiveThreshold);
 215   const base::Time keep_threshold =
 216       time_now - base::TimeDelta::FromDays(kAppKeepThreshold);
 217
 218   // Visit the apps in order of least recently to most recently launched.
 219   for (LaunchTimeAppMap::const_iterator it = app_launch_times.begin();
 220        it != app_launch_times.end(); ++it) {
 221     // Cannot remove apps that have been launched recently. So break when we
 222     // reach the new apps.
 223     if (it->first > keep_threshold)
 224         break;
 225
 226     // Remove ephemeral apps that have been inactive for a while or if the cache
 227     // is larger than the desired size.
 228     if (it->first < inactive_threshold || app_count > kMaxEphemeralAppsCount) {
 229       remove_app_ids->insert(it->second);
 230       --app_count;
 231     } else {
 232       break;
 233     }
 234   }
 235 }
 236
 237 void EphemeralAppService::GarbageCollectData() {
 238   ExtensionService* service =
 239       ExtensionSystem::Get(profile_)->extension_service();
 240   DCHECK(service);
 241   ExtensionPrefs* prefs = ExtensionPrefs::Get(profile_);
 242   DCHECK(prefs);
 243   scoped_ptr<ExtensionPrefs::ExtensionsInfo> evicted_apps_info(
 244       prefs->GetEvictedEphemeralAppsInfo());
 245
 246   base::Time time_now = base::Time::Now();
 247   const base::Time inactive_threshold =
 248       time_now - base::TimeDelta::FromDays(kDataInactiveThreshold);
 249
 250   for (size_t i = 0; i < evicted_apps_info->size(); ++i) {
 251     ExtensionInfo* info = evicted_apps_info->at(i).get();
 252     base::Time last_launch_time = prefs->GetLastLaunchTime(info->extension_id);
 253     if (last_launch_time > inactive_threshold)
 254       continue;
 255
 256     // Sanity check to ensure the app is not currently installed.
 257     if (service->GetInstalledExtension(info->extension_id)) {
 258       NOTREACHED();
 259       continue;
 260     }
 261
 262     // Ensure the app is not waiting to be installed.
 263     scoped_ptr<ExtensionInfo> delayed_install(
 264         prefs->GetDelayedInstallInfo(info->extension_id));
 265     if (delayed_install.get())
 266       continue;
 267
 268     if (info->extension_manifest.get()) {
 269       std::string error;
 270       scoped_refptr<const Extension> extension(Extension::Create(
 271           info->extension_path,
 272           info->extension_location,
 273           *info->extension_manifest,
 274           prefs->GetCreationFlags(info->extension_id),
 275           info->extension_id,
 276           &error));
 277
 278       if (extension.get())
 279         extensions::DataDeleter::StartDeleting(profile_, extension.get());
 280     }
 281
 282     prefs->RemoveEvictedEphemeralApp(info->extension_id);
 283   }
 284 }