Cache force-installed apps/extensions in device-local accounts

chrome/browser/chromeos/policy/device_local_account_policy_service.h

 // Copyright (c) 2012 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.
 
 #ifndef CHROME_BROWSER_CHROMEOS_POLICY_DEVICE_LOCAL_ACCOUNT_POLICY_SERVICE_H_
 #define CHROME_BROWSER_CHROMEOS_POLICY_DEVICE_LOCAL_ACCOUNT_POLICY_SERVICE_H_
 
 #include <map>
+#include <set>
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
+#include "chrome/browser/chromeos/extensions/device_local_account_external_policy_loader.h"
 #include "chrome/browser/chromeos/settings/cros_settings.h"
-#include "chrome/browser/policy/cloud/cloud_policy_core.h"
 #include "chrome/browser/policy/cloud/cloud_policy_store.h"
 
 namespace base {
 class SequencedTaskRunner;
 }
 
 namespace chromeos {
 class CrosSettings;

[Joao da Silva, 2013/10/17 14:57:54]

already #included

[bartfab (slow), 2013/10/18 12:58:39]

Done.

 class DeviceSettingsService;
 class SessionManagerClient;
 }
 
 namespace policy {
 
-class CloudPolicyClient;
+class CloudPolicyCore;
+struct DeviceLocalAccount;
 class DeviceLocalAccountPolicyStore;
 class DeviceManagementService;
 
 // The main switching central that downloads, caches, refreshes, etc. policy for
 // a single device-local account.
 class DeviceLocalAccountPolicyBroker {
  public:
   // |task_runner| is the runner for policy refresh tasks.
-  explicit DeviceLocalAccountPolicyBroker(
-      const std::string& user_id,
+  DeviceLocalAccountPolicyBroker(
+      const DeviceLocalAccount& account,
       scoped_ptr<DeviceLocalAccountPolicyStore> store,
       const scoped_refptr<base::SequencedTaskRunner>& task_runner);
   ~DeviceLocalAccountPolicyBroker();
 
+  const std::string& account_id() const { return account_id_; }
   const std::string& user_id() const { return user_id_; }

[Joao da Silva, 2013/10/17 14:57:54]

Document these two, it's not clear when each should be used. Or alternatively,
document these fields in DeviceLocalAccount and document here that these fields
refer to those others.

[bartfab (slow), 2013/10/18 12:58:39]

Done.

 
-  CloudPolicyCore* core() { return &core_; }
-  const CloudPolicyCore* core() const { return &core_; }
+  scoped_refptr<chromeos::DeviceLocalAccountExternalPolicyLoader>
+      extension_loader() const { return extension_loader_; }
 
-  // Establish a cloud connection for the service.
-  void Connect(scoped_ptr<CloudPolicyClient> client);
+  CloudPolicyCore* core() { return core_.get(); }
+  const CloudPolicyCore* core() const { return core_.get(); }
+
+  // Fire up the cloud connection for fetching policy for the account from the
+  // cloud if this is an enterprise-managed device.
+  void ConnectIfPossible(
+      chromeos::DeviceSettingsService* device_settings_service,
+      DeviceManagementService* device_management_service);
 
   // Destroy the cloud connection, stopping policy refreshes.
   void Disconnect();
 
   // Reads the refresh delay from policy and configures the refresh scheduler.
   void UpdateRefreshDelay();
 
   // Retrieves the display name for the account as stored in policy. Returns an
   // empty string if the policy is not present.
   std::string GetDisplayName() const;
 
  private:
+  const std::string account_id_;
   const std::string user_id_;
-  scoped_ptr<DeviceLocalAccountPolicyStore> store_;
-  CloudPolicyCore core_;
+  const scoped_ptr<DeviceLocalAccountPolicyStore> store_;
+  scoped_refptr<chromeos::DeviceLocalAccountExternalPolicyLoader>
+      extension_loader_;
+  scoped_ptr<CloudPolicyCore> core_;
 
   DISALLOW_COPY_AND_ASSIGN(DeviceLocalAccountPolicyBroker);
 };
 
 // Manages user policy blobs for device-local accounts present on the device.
 // The actual policy blobs are brokered by session_manager (to prevent file
 // manipulation), and we're making signature checks on the policy blobs to
 // ensure they're issued by the device owner.
 class DeviceLocalAccountPolicyService : public CloudPolicyStore::Observer {
  public:
   // Interface for interested parties to observe policy changes.
   class Observer {
    public:
     virtual ~Observer() {}
 
     // Policy for the given |user_id| has changed.
     virtual void OnPolicyUpdated(const std::string& user_id) = 0;
 
     // The list of accounts has been updated.
     virtual void OnDeviceLocalAccountsChanged() = 0;
   };
 
   DeviceLocalAccountPolicyService(
       chromeos::SessionManagerClient* session_manager_client,
       chromeos::DeviceSettingsService* device_settings_service,
-      chromeos::CrosSettings* cros_settings);
+      chromeos::CrosSettings* cros_settings,
+      scoped_refptr<base::SequencedTaskRunner> extension_cache_task_runner);
   virtual ~DeviceLocalAccountPolicyService();
 
   // Initializes the cloud policy service connection.
   void Connect(DeviceManagementService* device_management_service);
 
   // Prevents further policy fetches from the cloud.
   void Disconnect();
 
   // Get the policy broker for a given |user_id|. Returns NULL if that |user_id|
   // does not belong to an existing device-local account.
   DeviceLocalAccountPolicyBroker* GetBrokerForUser(const std::string& user_id);
 
   // Indicates whether policy has been successfully fetched for the given
   // |user_id|.
   bool IsPolicyAvailableForUser(const std::string& user_id);
 
   void AddObserver(Observer* observer);
   void RemoveObserver(Observer* observer);
 
   // CloudPolicyStore::Observer:
   virtual void OnStoreLoaded(CloudPolicyStore* store) OVERRIDE;
   virtual void OnStoreError(CloudPolicyStore* store) OVERRIDE;
 
  private:
-  struct PolicyBrokerWrapper {
-    PolicyBrokerWrapper();
+  typedef std::map<std::string, DeviceLocalAccountPolicyBroker*>
+      PolicyBrokerMap;
 
-    // Return the |broker|, creating it first if necessary.
-    DeviceLocalAccountPolicyBroker* GetBroker();
+  // Returns |true| if the directory in which force-installed extensions are
+  // cached for |account_id| is busy, either because a broker that was using
+  // this directory has not shut down completely yet or because the directory is
+  // being deleted.
+  bool IsExtensionCacheDirectoryBusy(const std::string& account_id);
 
-    // Fire up the cloud connection for fetching policy for the account from the
-    // cloud if this is an enterprise-managed device.
-    void ConnectIfPossible();
+  // Starts any extension caches that are not running yet but can be started now
+  // because their cache directories are no longer busy.
+  void StartExtensionCachesIfPossible();
 
-    // Destroy the cloud connection.
-    void Disconnect();
+  // Checks whether a broker exists for |account_id|. If so, starts the broker's
+  // extension cache and returns |true|. Otherwise, returns |false|.
+  bool StartExtensionCacheForAccountIfPresent(const std::string& account_id);
 
-    // Delete the broker.
-    void DeleteBroker();
+  // Called back when any extension caches belonging to device-local accounts
+  // that no longer exist have been removed at start-up.
+  void OnOrphanedExtensionCachesDeleted();
 
-    std::string user_id;
-    std::string account_id;
-    DeviceLocalAccountPolicyService* parent;
-    DeviceLocalAccountPolicyBroker* broker;
-  };
+  // Called back when the extension cache for |account_id| has been shut down.
+  void OnObsoleteExensionCacheShutdown(const std::string& account_id);

[Joao da Silva, 2013/10/17 14:57:54]

OnObsoleteExtensionCacheShutdown (missing "t")

[bartfab (slow), 2013/10/18 12:58:39]

Done.

 
-  typedef std::map<std::string, PolicyBrokerWrapper> PolicyBrokerMap;
+  // Called back when the extension cache for |account_id| has been removed.
+  void OnObsoleteExtensionCacheDeleted(const std::string& account_id);
 
   // Re-queries the list of defined device-local accounts from device settings
   // and updates |policy_brokers_| to match that list.
   void UpdateAccountList();
 
   // Calls |UpdateAccountList| if there are no previous calls pending.
   void UpdateAccountListIfNonePending();
 
   // Deletes brokers in |map| and clears it.
   void DeleteBrokers(PolicyBrokerMap* map);
 
   // Find the broker for a given |store|. Returns NULL if |store| is unknown.
   DeviceLocalAccountPolicyBroker* GetBrokerForStore(CloudPolicyStore* store);
 
   chromeos::SessionManagerClient* session_manager_client_;
   chromeos::DeviceSettingsService* device_settings_service_;
   chromeos::CrosSettings* cros_settings_;
 
   DeviceManagementService* device_management_service_;
 
   // The device-local account policy brokers, keyed by user ID.
   PolicyBrokerMap policy_brokers_;
 
+  // Whether a call to UpdateAccountList() is pending because |cros_settings_|
+  // are not trusted yet).

[Joao da Silva, 2013/10/17 14:57:54]

remove )

[bartfab (slow), 2013/10/18 12:58:39]

Done.

+  bool waiting_for_cros_settings_;
+
+  // Whether the process of removing orphaned extension caches at startup has
+  // been started.
+  bool orphaned_cache_deletion_started_;
+  // Whether the process of removing orphaned extension caches at startup has
+  // been completed.
+  bool orphaned_cache_deletion_finished_;
+
+  // Account IDs whose extension cache directories are busy, either because a
+  // broker for the account has not shut down completely yet or because the
+  // directory is being deleted.
+  std::set<std::string> busy_extension_cache_directories_;

[Joao da Silva, 2013/10/17 14:57:54]

I think you got the logic right but I'm wary of having the set and 3 bools; it's
quite a bit of state to track, and very easy to get wrong in a subsequent
extension/refactoring to this class.

It'd be extra nice if this could be simplified, but I'm not stopping this change
because of this :-)

[bartfab (slow), 2013/10/18 12:58:39]

I introduced an enum that combines the two bools into a single state.

+
+  // Background task runner on which all extension caches and cache directory
+  // removal tasks run.
+  const scoped_refptr<base::SequencedTaskRunner> extension_cache_task_runner_;
+
   ObserverList<Observer, true> observers_;
 
-  scoped_ptr<chromeos::CrosSettings::ObserverSubscription>
+  const scoped_ptr<chromeos::CrosSettings::ObserverSubscription>
       local_accounts_subscription_;
 
-  // Weak pointer factory for cros_settings_->PrepareTrustedValues() callbacks.
-  base::WeakPtrFactory<DeviceLocalAccountPolicyService>
-      cros_settings_callback_factory_;
+  base::WeakPtrFactory<DeviceLocalAccountPolicyService> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DeviceLocalAccountPolicyService);
 };
 
 }  // namespace policy
 
 #endif  // CHROME_BROWSER_CHROMEOS_POLICY_DEVICE_LOCAL_ACCOUNT_POLICY_SERVICE_H_