Show a notification when an ephemeral app consumes excessive disk space

chrome/browser/extensions/extension_storage_monitor.cc

Index: chrome/browser/extensions/extension_storage_monitor.cc
diff --git a/chrome/browser/extensions/extension_storage_monitor.cc b/chrome/browser/extensions/extension_storage_monitor.cc
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index 0000000000000000000000000000000000000000..fbc173432d236acdad56b8e0c292745b6945af33
--- /dev/null
+++ b/chrome/browser/extensions/extension_storage_monitor.cc
@@ -0,0 +1,453 @@
+// Copyright 2014 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/extensions/extension_storage_monitor.h"
+
+#include <map>
+
+#include "base/strings/string_number_conversions.h"
+#include "base/strings/string_util.h"
+#include "base/strings/utf_string_conversions.h"
+#include "chrome/browser/chrome_notification_types.h"
+#include "chrome/browser/extensions/extension_storage_monitor_factory.h"
+#include "chrome/browser/extensions/extension_util.h"
+#include "chrome/browser/extensions/image_loader.h"
+#include "chrome/common/extensions/manifest_handlers/app_launch_info.h"
+#include "chrome/common/extensions/manifest_handlers/icons_handler.h"
+#include "content/public/browser/browser_context.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/browser/notification_details.h"
+#include "content/public/browser/notification_source.h"
+#include "content/public/browser/storage_partition.h"
+#include "extensions/browser/extension_prefs.h"
+#include "extensions/browser/extension_registry.h"
+#include "extensions/common/extension.h"
+#include "grit/generated_resources.h"
+#include "ui/base/l10n/l10n_util.h"
+#include "ui/message_center/message_center.h"
+#include "ui/message_center/notifier_settings.h"
+#include "ui/message_center/views/constants.h"
+#include "webkit/browser/quota/quota_manager.h"
+#include "webkit/browser/quota/storage_observer.h"
+
+using content::BrowserThread;
+
+namespace extensions {
+
+namespace {
+
+// The rate at which we would like to observe storage events.
+const int kStorageEventRateSec = 30;
+
+// The storage type to monitor.
+const quota::StorageType kMonitorStorageType = quota::kStorageTypePersistent;
+
+// Set the thresholds for the first notification. Ephemeral apps have a lower
+// threshold than installed extensions and apps. Once a threshold is exceeded,
+// it will be doubled to throttle notifications.
+const int64 kMBytes = 1024 * 1024;
+const int64 kEphemeralAppInitialThreshold = 250 * kMBytes;
+const int64 kExtensionInitialThreshold = 1000 * kMBytes;
+
+// Notifications have an ID so that we can update them.
+const char kNotificationIdFormat[] = "ExtensionStorageMonitor-$1-$2";
+const char kSystemNotifierId[] = "ExtensionStorageMonitor";
+
+}  // namespace
+
+// StorageEventObserver monitors the storage usage of extensions and lives on
+// the IO thread. When a threshold is exceeded, a message will be posted to the
+// UI thread, which displays the notification.
+class StorageEventObserver
+    : public base::RefCountedThreadSafe<
+          StorageEventObserver,
+          BrowserThread::DeleteOnIOThread>,
+      public quota::StorageObserver {
+ public:
+  explicit StorageEventObserver(
+      base::WeakPtr<ExtensionStorageMonitor> storage_monitor)
+      : storage_monitor_(storage_monitor) {
+  }
+
+  // Register as an observer for the extension's storage events.
+  void StartObservingForExtension(
+      scoped_refptr<quota::QuotaManager> quota_manager,
+      const std::string& extension_id,
+      const GURL& site_url,
+      int64 next_threshold,
+      int rate) {
+    DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+    DCHECK(quota_manager.get());
+
+    GURL origin = site_url.GetOrigin();
+    StorageState& state = origin_state_map_[origin];
+    state.quota_manager = quota_manager;
+    state.extension_id = extension_id;
+    state.next_threshold = next_threshold;
+
+    quota::StorageObserver::MonitorParams params(
+        kMonitorStorageType,
+        origin,
+        base::TimeDelta::FromSeconds(rate),
+        false);
+    quota_manager->AddStorageObserver(this, params);
+  }
+
+  // Deregister as an observer for the extension's storage events.
+  void StopObservingForExtension(const std::string& extension_id) {
+    DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+
+    for (OriginStorageStateMap::iterator it = origin_state_map_.begin();
+         it != origin_state_map_.end(); ) {
+      if (it->second.extension_id == extension_id) {
+        quota::StorageObserver::Filter filter(kMonitorStorageType, it->first);
+        it->second.quota_manager->RemoveStorageObserverForFilter(this, filter);
+        origin_state_map_.erase(it++);
+      } else {
+        ++it;
+      }
+    }
+  }
+
+  // Stop observing all storage events. Called during shutdown.
+  void StopObserving() {
+    DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+
+    for (OriginStorageStateMap::iterator it = origin_state_map_.begin();
+         it != origin_state_map_.end(); ++it) {
+      it->second.quota_manager->RemoveStorageObserver(this);
+    }
+    origin_state_map_.clear();
+  }
+
+ private:
+  friend class base::DeleteHelper<StorageEventObserver>;
+  friend struct content::BrowserThread::DeleteOnThread<
+      content::BrowserThread::IO>;
+
+  struct StorageState {
+    scoped_refptr<quota::QuotaManager> quota_manager;
+    std::string extension_id;
+    int64 next_threshold;
+
+    StorageState() : next_threshold(0) {}
+  };
+  typedef std::map<GURL, StorageState> OriginStorageStateMap;
+
+  virtual ~StorageEventObserver() {
+    DCHECK(origin_state_map_.empty());
+    StopObserving();
+  }
+
+  // quota::StorageObserver implementation.
+  virtual void OnStorageEvent(const Event& event) OVERRIDE {
+    OriginStorageStateMap::iterator state =
+        origin_state_map_.find(event.filter.origin);
+    if (state == origin_state_map_.end())
+      return;
+
+    if (event.usage >= state->second.next_threshold) {
+      while (event.usage >= state->second.next_threshold)
+        state->second.next_threshold *= 2;
+
+      BrowserThread::PostTask(
+          BrowserThread::UI,
+          FROM_HERE,
+          base::Bind(&ExtensionStorageMonitor::OnStorageThresholdExceeded,
+                     storage_monitor_,
+                     state->second.extension_id,
+                     state->second.next_threshold,
+                     event.usage));
+    }
+  }
+
+  OriginStorageStateMap origin_state_map_;
+  base::WeakPtr<ExtensionStorageMonitor> storage_monitor_;
+};
+
+// ExtensionStorageMonitor
+
+// static
+ExtensionStorageMonitor* ExtensionStorageMonitor::Get(
+    content::BrowserContext* context) {
+  return ExtensionStorageMonitorFactory::GetForBrowserContext(context);
+}
+
+ExtensionStorageMonitor::ExtensionStorageMonitor(
+    content::BrowserContext* context)
+    : enable_for_all_extensions_(false),
+      initial_extension_threshold_(kExtensionInitialThreshold),
+      initial_ephemeral_threshold_(kEphemeralAppInitialThreshold),
+      observer_rate_(kStorageEventRateSec),
+      context_(context),
+      weak_ptr_factory_(this) {
+  registrar_.Add(this, chrome::NOTIFICATION_EXTENSION_UNINSTALLED,
+                 content::Source<content::BrowserContext>(context_));
+  registrar_.Add(this, chrome::NOTIFICATION_PROFILE_DESTROYED,
+                 content::Source<content::BrowserContext>(context_));
+
+  ExtensionRegistry* registry = ExtensionRegistry::Get(context_);
+  DCHECK(registry);
+  registry->AddObserver(this);
+}
+
+ExtensionStorageMonitor::~ExtensionStorageMonitor() {}
+
+void ExtensionStorageMonitor::Observe(
+    int type,
+    const content::NotificationSource& source,
+    const content::NotificationDetails& details) {
+  switch (type) {
+    case chrome::NOTIFICATION_EXTENSION_UNINSTALLED: {
+      const Extension* extension =
+          content::Details<const Extension>(details).ptr();
+      RemoveNotificationForExtension(extension->id());
+      break;
+    }
+    case chrome::NOTIFICATION_PROFILE_DESTROYED: {
+      StopMonitoringAll();
+      break;
+    }
+    default:
+      NOTREACHED();
+  };
+}
+
+void ExtensionStorageMonitor::OnExtensionLoaded(
+    content::BrowserContext* browser_context,
+    const Extension* extension) {
+  DCHECK(extension);
+  StartMonitoringStorage(extension);
+}
+
+void ExtensionStorageMonitor::OnExtensionUnloaded(
+    content::BrowserContext* browser_context,
+    const Extension* extension) {
+  DCHECK(extension);
+  StopMonitoringStorage(extension->id());
+}
+
+std::string ExtensionStorageMonitor::GetNotificationId(
+    const std::string& extension_id) {
+  std::vector<std::string> placeholders;
+  placeholders.push_back(context_->GetPath().BaseName().MaybeAsASCII());
+  placeholders.push_back(extension_id);
+
+  return ReplaceStringPlaceholders(kNotificationIdFormat, placeholders, NULL);
+}
+
+void ExtensionStorageMonitor::OnStorageThresholdExceeded(
+    const std::string& extension_id,
+    int64 next_threshold,
+    int64 current_usage) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+
+  const Extension* extension = ExtensionRegistry::Get(context_)->
+      GetExtensionById(extension_id, ExtensionRegistry::EVERYTHING);
+  if (!extension)
+    return;
+
+  ExtensionPrefs* prefs = ExtensionPrefs::Get(context_);
+  DCHECK(prefs);
+  prefs->SetNextStorageThreshold(extension->id(), next_threshold);
+
+  const int kIconSize = message_center::kNotificationIconSize;
+  ExtensionResource resource =  IconsInfo::GetIconResource(
+      extension, kIconSize, ExtensionIconSet::MATCH_BIGGER);
+  ImageLoader::Get(context_)->LoadImageAsync(
+      extension, resource, gfx::Size(kIconSize, kIconSize),
+      base::Bind(&ExtensionStorageMonitor::OnImageLoaded,
+                 weak_ptr_factory_.GetWeakPtr(),
+                 extension_id,
+                 current_usage));
+}
+
+void ExtensionStorageMonitor::OnImageLoaded(
+    const std::string& extension_id,
+    int64 current_usage,
+    const gfx::Image& image) {
+  const Extension* extension = ExtensionRegistry::Get(context_)->
+      GetExtensionById(extension_id, ExtensionRegistry::EVERYTHING);
+  if (!extension)
+    return;
+
+  // Remove any existing notifications to force a new notification to pop up.
+  std::string notification_id(GetNotificationId(extension_id));
+  message_center::MessageCenter::Get()->RemoveNotification(
+      notification_id, false);
+
+  message_center::RichNotificationData notification_data;
+  notification_data.buttons.push_back(message_center::ButtonInfo(
+      l10n_util::GetStringUTF16(extension->is_app() ?
+          IDS_EXTENSION_STORAGE_MONITOR_BUTTON_DISMISS_APP :
+          IDS_EXTENSION_STORAGE_MONITOR_BUTTON_DISMISS_EXTENSION)));
+
+  gfx::Image notification_image(image);
+  if (notification_image.IsEmpty()) {
+    notification_image =
+        extension->is_app() ? gfx::Image(IconsInfo::GetDefaultAppIcon())
+                            : gfx::Image(IconsInfo::GetDefaultExtensionIcon());
+  }
+
+  scoped_ptr<message_center::Notification> notification;
+  notification.reset(new message_center::Notification(
+      message_center::NOTIFICATION_TYPE_SIMPLE,
+      notification_id,
+      l10n_util::GetStringUTF16(IDS_EXTENSION_STORAGE_MONITOR_TITLE),
+      l10n_util::GetStringFUTF16(
+          IDS_EXTENSION_STORAGE_MONITOR_TEXT,
+          base::UTF8ToUTF16(extension->name()),
+          base::IntToString16(current_usage / kMBytes)),
+      notification_image,
+      base::string16() /* display source */,
+      message_center::NotifierId(
+          message_center::NotifierId::SYSTEM_COMPONENT, kSystemNotifierId),
+      notification_data,
+      new message_center::HandleNotificationButtonClickDelegate(base::Bind(
+          &ExtensionStorageMonitor::OnNotificationButtonClick,
+          weak_ptr_factory_.GetWeakPtr(),
+          extension_id))));
+  notification->SetSystemPriority();
+  message_center::MessageCenter::Get()->AddNotification(notification.Pass());
+
+  notified_extension_ids_.insert(extension_id);
+}
+
+void ExtensionStorageMonitor::OnNotificationButtonClick(
+    const std::string& extension_id, int button_index) {
+  switch (button_index) {
+    case BUTTON_DISABLE_NOTIFICATION: {
+      DisableStorageMonitoring(extension_id);
+      break;
+    }
+    default:
+      NOTREACHED();
+  };
+}
+
+void ExtensionStorageMonitor::DisableStorageMonitoring(
+    const std::string& extension_id) {
+  StopMonitoringStorage(extension_id);
+
+  ExtensionPrefs* prefs = ExtensionPrefs::Get(context_);
+  DCHECK(prefs);
+  prefs->SetStorageNotificationEnabled(extension_id, false);
+
+  message_center::MessageCenter::Get()->RemoveNotification(
+      GetNotificationId(extension_id), false);
+}
+
+void ExtensionStorageMonitor::StartMonitoringStorage(
+    const Extension* extension) {
+  if (!extension->HasAPIPermission(APIPermission::kUnlimitedStorage))
+    return;
+
+  // Do not monitor storage for component extensions.
+  if (extension->location() == Manifest::COMPONENT)
+    return;
+
+  // First apply this feature only to experimental ephemeral apps. If it works
+  // well, roll it out to all extensions and apps.
+  if (!extension->is_ephemeral() && !enable_for_all_extensions_)
+    return;
+
+  ExtensionPrefs* prefs = ExtensionPrefs::Get(context_);
+  DCHECK(prefs);
+  if (!prefs->IsStorageNotificationEnabled(extension->id()))
+    return;
+
+  // Lazily create the storage monitor proxy on the IO thread.
+  if (!storage_observer_.get()) {
+    storage_observer_ =
+        new StorageEventObserver(weak_ptr_factory_.GetWeakPtr());
+  }
+
+  GURL site_url =
+      extensions::util::GetSiteForExtensionId(extension->id(), context_);
+  content::StoragePartition* storage_partition =
+      content::BrowserContext::GetStoragePartitionForSite(context_, site_url);
+  DCHECK(storage_partition);
+  scoped_refptr<quota::QuotaManager> quota_manager(
+      storage_partition->GetQuotaManager());
+
+  GURL storage_origin(site_url.GetOrigin());
+  if (extension->is_hosted_app())
+    storage_origin = AppLaunchInfo::GetLaunchWebURL(extension).GetOrigin();
+
+  int next_threshold = prefs->GetNextStorageThreshold(extension->id());
+  if (next_threshold == 0) {
+    // The next threshold is written to the prefs after the initial threshold is
+    // exceeded.
+    next_threshold = extension->is_ephemeral() ? initial_ephemeral_threshold_
+                                               : initial_extension_threshold_;
+  }
+
+  BrowserThread::PostTask(
+      BrowserThread::IO,
+      FROM_HERE,
+      base::Bind(&StorageEventObserver::StartObservingForExtension,
+                 storage_observer_,
+                 quota_manager,
+                 extension->id(),
+                 storage_origin,
+                 next_threshold,
+                 observer_rate_));
+}
+
+void ExtensionStorageMonitor::StopMonitoringStorage(
+    const std::string& extension_id) {
+  if (!storage_observer_.get())
+    return;
+
+  BrowserThread::PostTask(
+      BrowserThread::IO,
+      FROM_HERE,
+      base::Bind(&StorageEventObserver::StopObservingForExtension,
+                 storage_observer_,
+                 extension_id));
+}
+
+void ExtensionStorageMonitor::StopMonitoringAll() {
+  ExtensionRegistry* registry = ExtensionRegistry::Get(context_);
+  DCHECK(registry);
+  registry->RemoveObserver(this);
+
+  RemoveAllNotifications();
+
+  if (!storage_observer_.get())
+    return;
+
+  BrowserThread::PostTask(
+      BrowserThread::IO,
+      FROM_HERE,
+      base::Bind(&StorageEventObserver::StopObserving, storage_observer_));
+  storage_observer_ = NULL;
+}
+
+void ExtensionStorageMonitor::RemoveNotificationForExtension(
+    const std::string& extension_id) {
+  std::set<std::string>::iterator ext_id =
+      notified_extension_ids_.find(extension_id);
+  if (ext_id == notified_extension_ids_.end())
+    return;
+
+  notified_extension_ids_.erase(ext_id);
+  message_center::MessageCenter::Get()->RemoveNotification(
+      GetNotificationId(extension_id), false);
+}
+
+void ExtensionStorageMonitor::RemoveAllNotifications() {
+  if (notified_extension_ids_.empty())
+    return;
+
+  message_center::MessageCenter* center = message_center::MessageCenter::Get();
+  DCHECK(center);
+  for (std::set<std::string>::iterator it = notified_extension_ids_.begin();
+       it != notified_extension_ids_.end(); ++it) {
+    center->RemoveNotification(GetNotificationId(*it), false);
+  }
+  notified_extension_ids_.clear();
+}
+
+}  // namespace extensions