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 "apps/app_lifetime_monitor_factory.h"
   8 #include "base/command_line.h"
   9 #include "base/location.h"
  10 #include "base/single_thread_task_runner.h"
  11 #include "base/thread_task_runner_handle.h"
  12 #include "chrome/browser/apps/ephemeral_app_service_factory.h"
  13 #include "chrome/browser/extensions/extension_service.h"
  14 #include "chrome/browser/extensions/extension_util.h"
  15 #include "chrome/browser/profiles/profile.h"
  16 #include "chrome/common/chrome_switches.h"
  17 #include "extensions/browser/extension_prefs.h"
  18 #include "extensions/browser/extension_registry.h"
  19 #include "extensions/browser/extension_system.h"
  20 #include "extensions/browser/extension_util.h"
  21 #include "extensions/browser/uninstall_reason.h"
  22 #include "extensions/common/extension.h"
  23 #include "extensions/common/extension_set.h"
  24 #include "extensions/common/one_shot_event.h"
  25
  26 using extensions::Extension;
  27 using extensions::ExtensionPrefs;
  28 using extensions::ExtensionRegistry;
  29 using extensions::ExtensionSet;
  30 using extensions::ExtensionSystem;
  31
  32 namespace {
  33
  34 // The number of seconds after startup before performing garbage collection
  35 // of ephemeral apps.
  36 const int kGarbageCollectAppsStartupDelay = 60;
  37
  38 // The number of seconds after an ephemeral app has been installed before
  39 // performing garbage collection.
  40 const int kGarbageCollectAppsInstallDelay = 15;
  41
  42 // When the number of ephemeral apps reaches this count, trigger garbage
  43 // collection to trim off the least-recently used apps in excess of
  44 // kMaxEphemeralAppsCount.
  45 const int kGarbageCollectAppsTriggerCount = 35;
  46
  47 // The number of seconds after an app has stopped running before it will be
  48 // disabled.
  49 const int kDefaultDisableAppDelay = 1;
  50
  51 // The number of seconds after startup before disabling inactive ephemeral apps.
  52 const int kDisableAppsOnStartupDelay = 5;
  53
  54 }  // namespace
  55
  56 const int EphemeralAppService::kAppInactiveThreshold = 10;
  57 const int EphemeralAppService::kAppKeepThreshold = 1;
  58 const int EphemeralAppService::kMaxEphemeralAppsCount = 30;
  59
  60 // static
  61 EphemeralAppService* EphemeralAppService::Get(Profile* profile) {
  62   return EphemeralAppServiceFactory::GetForProfile(profile);
  63 }
  64
  65 EphemeralAppService::EphemeralAppService(Profile* profile)
  66     : profile_(profile),
  67       extension_registry_observer_(this),
  68       app_lifetime_monitor_observer_(this),
  69       ephemeral_app_count_(-1),
  70       disable_idle_app_delay_(kDefaultDisableAppDelay),
  71       weak_ptr_factory_(this) {
  72   ExtensionSystem::Get(profile_)->ready().Post(
  73       FROM_HERE,
  74       base::Bind(&EphemeralAppService::Init, weak_ptr_factory_.GetWeakPtr()));
  75 }
  76
  77 EphemeralAppService::~EphemeralAppService() {
  78 }
  79
  80 void EphemeralAppService::ClearCachedApps() {
  81   // Cancel any pending garbage collects.
  82   garbage_collect_apps_timer_.Stop();
  83
  84   ExtensionRegistry* registry = ExtensionRegistry::Get(profile_);
  85   DCHECK(registry);
  86   ExtensionPrefs* prefs = ExtensionPrefs::Get(profile_);
  87   DCHECK(prefs);
  88   ExtensionService* service =
  89       ExtensionSystem::Get(profile_)->extension_service();
  90   DCHECK(service);
  91
  92   scoped_ptr<ExtensionSet> extensions =
  93       registry->GenerateInstalledExtensionsSet();
  94
  95   for (ExtensionSet::const_iterator it = extensions->begin();
  96        it != extensions->end();
  97        ++it) {
  98     std::string extension_id = (*it)->id();
  99     if (!prefs->IsEphemeralApp(extension_id))
 100       continue;
 101
 102     // Do not remove apps that are running.
 103     if (!extensions::util::IsExtensionIdle(extension_id, profile_))
 104       continue;
 105
 106     DCHECK(registry->GetExtensionById(extension_id,
 107                                       ExtensionRegistry::EVERYTHING));
 108     service->UninstallExtension(
 109         extension_id,
 110         extensions::UNINSTALL_REASON_ORPHANED_EPHEMERAL_EXTENSION,
 111         base::Bind(&base::DoNothing),
 112         NULL);
 113   }
 114 }
 115
 116 void EphemeralAppService::OnExtensionWillBeInstalled(
 117     content::BrowserContext* browser_context,
 118     const extensions::Extension* extension,
 119     bool is_update,
 120     bool from_ephemeral,
 121     const std::string& old_name) {
 122   if (from_ephemeral) {
 123     // An ephemeral app was just promoted to a regular installed app.
 124     --ephemeral_app_count_;
 125     DCHECK_GE(ephemeral_app_count_, 0);
 126     HandleEphemeralAppPromoted(extension);
 127   } else if (!is_update &&
 128              extensions::util::IsEphemeralApp(extension->id(), profile_)) {
 129     // A new ephemeral app was launched.
 130     ++ephemeral_app_count_;
 131     if (ephemeral_app_count_ >= kGarbageCollectAppsTriggerCount) {
 132       TriggerGarbageCollect(
 133           base::TimeDelta::FromSeconds(kGarbageCollectAppsInstallDelay));
 134     }
 135   }
 136 }
 137
 138 void EphemeralAppService::OnExtensionUninstalled(
 139     content::BrowserContext* browser_context,
 140     const extensions::Extension* extension,
 141     extensions::UninstallReason reason) {
 142   if (extensions::util::IsEphemeralApp(extension->id(), profile_)) {
 143     --ephemeral_app_count_;
 144     DCHECK_GE(ephemeral_app_count_, 0);
 145   }
 146 }
 147
 148 void EphemeralAppService::OnAppStop(Profile* profile,
 149                                     const std::string& app_id) {
 150   if (!extensions::util::IsEphemeralApp(app_id, profile_))
 151     return;
 152
 153   base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
 154       FROM_HERE, base::Bind(&EphemeralAppService::DisableEphemeralApp,
 155                             weak_ptr_factory_.GetWeakPtr(), app_id),
 156       base::TimeDelta::FromSeconds(disable_idle_app_delay_));
 157 }
 158
 159 void EphemeralAppService::OnChromeTerminating() {
 160   garbage_collect_apps_timer_.Stop();
 161
 162   extension_registry_observer_.RemoveAll();
 163   app_lifetime_monitor_observer_.RemoveAll();
 164 }
 165
 166 void EphemeralAppService::Init() {
 167   InitEphemeralAppCount();
 168
 169   // Start observing.
 170   extension_registry_observer_.Add(ExtensionRegistry::Get(profile_));
 171   app_lifetime_monitor_observer_.Add(
 172       apps::AppLifetimeMonitorFactory::GetForProfile(profile_));
 173
 174   // Execute startup clean up tasks (except during tests).
 175   if (base::CommandLine::ForCurrentProcess()->HasSwitch(switches::kTestType))
 176     return;
 177
 178   TriggerGarbageCollect(
 179       base::TimeDelta::FromSeconds(kGarbageCollectAppsStartupDelay));
 180
 181   base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
 182       FROM_HERE, base::Bind(&EphemeralAppService::DisableEphemeralAppsOnStartup,
 183                             weak_ptr_factory_.GetWeakPtr()),
 184       base::TimeDelta::FromSeconds(kDisableAppsOnStartupDelay));
 185 }
 186
 187 void EphemeralAppService::InitEphemeralAppCount() {
 188   scoped_ptr<ExtensionSet> extensions =
 189       ExtensionRegistry::Get(profile_)->GenerateInstalledExtensionsSet();
 190   ExtensionPrefs* prefs = ExtensionPrefs::Get(profile_);
 191   DCHECK(prefs);
 192
 193   ephemeral_app_count_ = 0;
 194   for (ExtensionSet::const_iterator it = extensions->begin();
 195        it != extensions->end(); ++it) {
 196     const Extension* extension = it->get();
 197     if (prefs->IsEphemeralApp(extension->id()))
 198       ++ephemeral_app_count_;
 199   }
 200 }
 201
 202 void EphemeralAppService::DisableEphemeralApp(const std::string& app_id) {
 203   if (!extensions::util::IsEphemeralApp(app_id, profile_) ||
 204       !extensions::util::IsExtensionIdle(app_id, profile_)) {
 205     return;
 206   }
 207
 208   // After an ephemeral app has stopped running, unload it from extension
 209   // system and disable it to prevent all background activity.
 210   ExtensionService* service =
 211       ExtensionSystem::Get(profile_)->extension_service();
 212   DCHECK(service);
 213   service->DisableExtension(app_id, Extension::DISABLE_INACTIVE_EPHEMERAL_APP);
 214 }
 215
 216 void EphemeralAppService::DisableEphemeralAppsOnStartup() {
 217   ExtensionPrefs* prefs = ExtensionPrefs::Get(profile_);
 218   DCHECK(prefs);
 219   ExtensionService* service =
 220       ExtensionSystem::Get(profile_)->extension_service();
 221   DCHECK(service);
 222
 223   // Ensure that all inactive ephemeral apps are disabled to prevent all
 224   // background activity. This is done on startup to catch any apps that escaped
 225   // being disabled on shutdown.
 226   scoped_ptr<ExtensionSet> extensions =
 227       ExtensionRegistry::Get(profile_)->GenerateInstalledExtensionsSet();
 228   for (ExtensionSet::const_iterator it = extensions->begin();
 229        it != extensions->end();
 230        ++it) {
 231     const Extension* extension = it->get();
 232     if (!prefs->IsEphemeralApp(extension->id()))
 233       continue;
 234
 235     // Only V2 apps are installed ephemerally. Remove other ephemeral app types
 236     // that were cached before this policy was introduced.
 237     if (!extension->is_platform_app()) {
 238       service->UninstallExtension(
 239           extension->id(),
 240           extensions::UNINSTALL_REASON_ORPHANED_EPHEMERAL_EXTENSION,
 241           base::Bind(&base::DoNothing),
 242           NULL);
 243       continue;
 244     }
 245
 246     if (!prefs->HasDisableReason(extension->id(),
 247                                  Extension::DISABLE_INACTIVE_EPHEMERAL_APP) &&
 248         !prefs->IsExtensionRunning(extension->id()) &&
 249         extensions::util::IsExtensionIdle(extension->id(), profile_)) {
 250       service->DisableExtension(extension->id(),
 251                                 Extension::DISABLE_INACTIVE_EPHEMERAL_APP);
 252     }
 253   }
 254 }
 255
 256 void EphemeralAppService::HandleEphemeralAppPromoted(const Extension* app) {
 257   // When ephemeral apps are promoted to regular install apps, remove the
 258   // DISABLE_INACTIVE_EPHEMERAL_APP reason and enable the app if there are no
 259   // other reasons.
 260   ExtensionPrefs* prefs = ExtensionPrefs::Get(profile_);
 261   DCHECK(prefs);
 262
 263   int disable_reasons = prefs->GetDisableReasons(app->id());
 264   if (disable_reasons & Extension::DISABLE_INACTIVE_EPHEMERAL_APP) {
 265     prefs->RemoveDisableReason(app->id(),
 266                                Extension::DISABLE_INACTIVE_EPHEMERAL_APP);
 267     if (disable_reasons == Extension::DISABLE_INACTIVE_EPHEMERAL_APP)
 268       prefs->SetExtensionState(app->id(), Extension::ENABLED);
 269   }
 270 }
 271
 272 void EphemeralAppService::TriggerGarbageCollect(const base::TimeDelta& delay) {
 273   if (!garbage_collect_apps_timer_.IsRunning()) {
 274     garbage_collect_apps_timer_.Start(
 275         FROM_HERE,
 276         delay,
 277         this,
 278         &EphemeralAppService::GarbageCollectApps);
 279   }
 280 }
 281
 282 void EphemeralAppService::GarbageCollectApps() {
 283   ExtensionRegistry* registry = ExtensionRegistry::Get(profile_);
 284   DCHECK(registry);
 285   ExtensionPrefs* prefs = ExtensionPrefs::Get(profile_);
 286   DCHECK(prefs);
 287
 288   scoped_ptr<ExtensionSet> extensions =
 289       registry->GenerateInstalledExtensionsSet();
 290
 291   int app_count = 0;
 292   LaunchTimeAppMap app_launch_times;
 293   std::set<std::string> remove_app_ids;
 294
 295   // Populate a list of ephemeral apps, ordered by their last launch time.
 296   for (ExtensionSet::const_iterator it = extensions->begin();
 297        it != extensions->end(); ++it) {
 298     const Extension* extension = it->get();
 299     if (!prefs->IsEphemeralApp(extension->id()))
 300       continue;
 301
 302     ++app_count;
 303
 304     // Do not remove ephemeral apps that are running.
 305     if (!extensions::util::IsExtensionIdle(extension->id(), profile_))
 306       continue;
 307
 308     base::Time last_launch_time = prefs->GetLastLaunchTime(extension->id());
 309
 310     // If the last launch time is invalid, this may be because it was just
 311     // installed. So use the install time. If this is also null for some reason,
 312     // the app will be removed.
 313     if (last_launch_time.is_null())
 314       last_launch_time = prefs->GetInstallTime(extension->id());
 315
 316     app_launch_times.insert(std::make_pair(last_launch_time, extension->id()));
 317   }
 318
 319   ExtensionService* service =
 320       ExtensionSystem::Get(profile_)->extension_service();
 321   DCHECK(service);
 322   // Execute the eviction policies and remove apps marked for deletion.
 323   if (!app_launch_times.empty()) {
 324     GetAppsToRemove(app_count, app_launch_times, &remove_app_ids);
 325
 326     for (std::set<std::string>::const_iterator id = remove_app_ids.begin();
 327          id != remove_app_ids.end(); ++id) {
 328       // Protect against cascading uninstalls.
 329       if (!registry->GetExtensionById(*id, ExtensionRegistry::EVERYTHING))
 330         continue;
 331
 332       service->UninstallExtension(
 333           *id,
 334           extensions::UNINSTALL_REASON_ORPHANED_EPHEMERAL_EXTENSION,
 335           base::Bind(&base::DoNothing),
 336           NULL);
 337     }
 338   }
 339 }
 340
 341 // static
 342 void EphemeralAppService::GetAppsToRemove(
 343     int app_count,
 344     const LaunchTimeAppMap& app_launch_times,
 345     std::set<std::string>* remove_app_ids) {
 346   base::Time time_now = base::Time::Now();
 347   const base::Time inactive_threshold =
 348       time_now - base::TimeDelta::FromDays(kAppInactiveThreshold);
 349   const base::Time keep_threshold =
 350       time_now - base::TimeDelta::FromDays(kAppKeepThreshold);
 351
 352   // Visit the apps in order of least recently to most recently launched.
 353   for (LaunchTimeAppMap::const_iterator it = app_launch_times.begin();
 354        it != app_launch_times.end(); ++it) {
 355     // Cannot remove apps that have been launched recently. So break when we
 356     // reach the new apps.
 357     if (it->first > keep_threshold)
 358         break;
 359
 360     // Remove ephemeral apps that have been inactive for a while or if the cache
 361     // is larger than the desired size.
 362     if (it->first < inactive_threshold || app_count > kMaxEphemeralAppsCount) {
 363       remove_app_ids->insert(it->second);
 364       --app_count;
 365     } else {
 366       break;
 367     }
 368   }
 369 }