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

chrome/browser/chromeos/policy/device_local_account_policy_service.cc

Index: chrome/browser/chromeos/policy/device_local_account_policy_service.cc
diff --git a/chrome/browser/chromeos/policy/device_local_account_policy_service.cc b/chrome/browser/chromeos/policy/device_local_account_policy_service.cc
index 825d39c38d3c23699cc1c7cee20c46aea90f8a08..3579bec7a2466f76f4e58505d2c0bca3e509d302 100644
--- a/chrome/browser/chromeos/policy/device_local_account_policy_service.cc
+++ b/chrome/browser/chromeos/policy/device_local_account_policy_service.cc
@@ -7,18 +7,24 @@
 #include <vector>
 
 #include "base/bind.h"
+#include "base/file_util.h"
+#include "base/files/file_enumerator.h"
+#include "base/files/file_path.h"
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
 #include "base/message_loop/message_loop_proxy.h"
+#include "base/path_service.h"
+#include "base/sequenced_task_runner.h"
+#include "base/strings/string_number_conversions.h"
 #include "chrome/browser/chromeos/policy/device_local_account.h"
 #include "chrome/browser/chromeos/policy/device_local_account_policy_store.h"
-#include "chrome/browser/chromeos/settings/cros_settings.h"
 #include "chrome/browser/chromeos/settings/device_settings_service.h"
 #include "chrome/browser/policy/cloud/cloud_policy_client.h"
 #include "chrome/browser/policy/cloud/cloud_policy_constants.h"
 #include "chrome/browser/policy/cloud/cloud_policy_refresh_scheduler.h"
 #include "chrome/browser/policy/cloud/device_management_service.h"
 #include "chrome/browser/policy/proto/cloud/device_management_backend.pb.h"
+#include "chromeos/chromeos_paths.h"
 #include "chromeos/dbus/session_manager_client.h"
 #include "chromeos/settings/cros_settings_names.h"
 #include "chromeos/settings/cros_settings_provider.h"
@@ -53,23 +59,86 @@ scoped_ptr<CloudPolicyClient> CreateClient(
   return client.Pass();
 }
 
+// Get the subdirectory of the cache directory in which force-installed
+// extensions are cached for |account_id|.
+std::string GetCacheSubdirectoryForAccountID(const std::string& account_id) {
+  return base::HexEncode(account_id.c_str(), account_id.size());
+}
+
+// Cleans up the cache directory by removing subdirectories that are not found
+// in |subdirectories_to_keep|. Only caches whose cache directory is found in
+// |subdirectories_to_keep| may be running while the clean-up is in progress.
+void DeleteOrphanedExtensionCaches(
+    const std::set<std::string>& subdirectories_to_keep) {
+  base::FilePath cache_root_dir;
+  CHECK(PathService::Get(chromeos::DIR_DEVICE_LOCAL_ACCOUNT_CACHE,
+                         &cache_root_dir));
+  base::FileEnumerator enumerator(cache_root_dir,
+                                  false,
+                                  base::FileEnumerator::DIRECTORIES);
+  for (base::FilePath path = enumerator.Next(); !path.empty();
+       path = enumerator.Next()) {
+    const std::string subdirectory(path.BaseName().MaybeAsASCII());
+    if (subdirectories_to_keep.find(subdirectory) ==
+        subdirectories_to_keep.end()) {
+      base::DeleteFile(path, true);
+    }
+  }
+}
+
+// Removes the subdirectory belonging to |account_id_to_delete| from the cache
+// directory. No cache belonging to |account_id_to_delete| may be running while
+// the removal is in progress.
+void DeleteObsoleteExtensionCache(const std::string& account_id_to_delete) {
+  base::FilePath cache_root_dir;
+  CHECK(PathService::Get(chromeos::DIR_DEVICE_LOCAL_ACCOUNT_CACHE,
+                         &cache_root_dir));
+  const base::FilePath path = cache_root_dir
+      .Append(GetCacheSubdirectoryForAccountID(account_id_to_delete));
+  if (base::DirectoryExists(path))
+    base::DeleteFile(path, true);
+}
+
 }  // namespace
 
 DeviceLocalAccountPolicyBroker::DeviceLocalAccountPolicyBroker(
-    const std::string& user_id,
+    const DeviceLocalAccount& account,
     scoped_ptr<DeviceLocalAccountPolicyStore> store,
     const scoped_refptr<base::SequencedTaskRunner>& task_runner)
-    : user_id_(user_id),
+    : account_id_(account.account_id),
+      user_id_(account.user_id),
       store_(store.Pass()),
       core_(PolicyNamespaceKey(dm_protocol::kChromePublicAccountPolicyType,
                                store_->account_id()),
             store_.get(),
-            task_runner) {}
+            task_runner) {
+  base::FilePath cache_root_dir;
+  CHECK(PathService::Get(chromeos::DIR_DEVICE_LOCAL_ACCOUNT_CACHE,
+                         &cache_root_dir));
+  extension_loader_ = new chromeos::DeviceLocalAccountExternalPolicyLoader(
+      store_.get(),
+      cache_root_dir.Append(
+          GetCacheSubdirectoryForAccountID(account.account_id)));
+}
 
-DeviceLocalAccountPolicyBroker::~DeviceLocalAccountPolicyBroker() {}
+DeviceLocalAccountPolicyBroker::~DeviceLocalAccountPolicyBroker() {
+}
+
+void DeviceLocalAccountPolicyBroker::Initialize() {
+  store_->Load();
+}
+
+void DeviceLocalAccountPolicyBroker::ConnectIfPossible(
+    chromeos::DeviceSettingsService* device_settings_service,
+    DeviceManagementService* device_management_service) {
+  if (core_.client())
+    return;
+
+  scoped_ptr<CloudPolicyClient> client(CreateClient(device_settings_service,
+                                                    device_management_service));
+  if (!client)
+    return;
 
-void DeviceLocalAccountPolicyBroker::Connect(
-    scoped_ptr<CloudPolicyClient> client) {
   core_.Connect(client.Pass());
   core_.StartRefreshScheduler();
   UpdateRefreshDelay();
@@ -98,66 +167,26 @@ std::string DeviceLocalAccountPolicyBroker::GetDisplayName() const {
   return display_name;
 }
 
-DeviceLocalAccountPolicyService::PolicyBrokerWrapper::PolicyBrokerWrapper()
-    : parent(NULL), broker(NULL) {}
-
-DeviceLocalAccountPolicyService::PolicyBrokerWrapper::~PolicyBrokerWrapper() {}
-
-DeviceLocalAccountPolicyBroker*
-    DeviceLocalAccountPolicyService::PolicyBrokerWrapper::GetBroker() {
-  if (!broker) {
-    scoped_ptr<DeviceLocalAccountPolicyStore> store(
-        new DeviceLocalAccountPolicyStore(account_id,
-                                          parent->session_manager_client_,
-                                          parent->device_settings_service_,
-                                          parent->background_task_runner_));
-    broker = new DeviceLocalAccountPolicyBroker(
-        user_id, store.Pass(), base::MessageLoopProxy::current());
-    broker->core()->store()->AddObserver(parent);
-    broker->core()->store()->Load();
-  }
-  return broker;
-}
-
-void DeviceLocalAccountPolicyService::PolicyBrokerWrapper::ConnectIfPossible() {
-  if (broker && broker->core()->client())
-    return;
-  scoped_ptr<CloudPolicyClient> client(CreateClient(
-      parent->device_settings_service_,
-      parent->device_management_service_));
-  if (client)
-    GetBroker()->Connect(client.Pass());
-}
-
-void DeviceLocalAccountPolicyService::PolicyBrokerWrapper::Disconnect() {
-  if (broker)
-    broker->Disconnect();
-}
-
-void DeviceLocalAccountPolicyService::PolicyBrokerWrapper::DeleteBroker() {
-  if (!broker)
-    return;
-  broker->core()->store()->RemoveObserver(parent);
-  delete broker;
-  broker = NULL;
-}
-
 DeviceLocalAccountPolicyService::DeviceLocalAccountPolicyService(
     chromeos::SessionManagerClient* session_manager_client,
     chromeos::DeviceSettingsService* device_settings_service,
     chromeos::CrosSettings* cros_settings,
-    scoped_refptr<base::SequencedTaskRunner> background_task_runner)
+    scoped_refptr<base::SequencedTaskRunner> store_background_task_runner,
+    scoped_refptr<base::SequencedTaskRunner> extension_cache_task_runner)
     : session_manager_client_(session_manager_client),
       device_settings_service_(device_settings_service),
       cros_settings_(cros_settings),
       device_management_service_(NULL),
-      background_task_runner_(background_task_runner),
-      cros_settings_callback_factory_(this) {
-  local_accounts_subscription_ = cros_settings_->AddSettingsObserver(
-      chromeos::kAccountsPrefDeviceLocalAccounts,
-      base::Bind(&DeviceLocalAccountPolicyService::
-                     UpdateAccountListIfNonePending,
-                 base::Unretained(this)));
+      waiting_for_cros_settings_(false),
+      orphan_cache_deletion_state_(NOT_STARTED),
+      store_background_task_runner_(store_background_task_runner),
+      extension_cache_task_runner_(extension_cache_task_runner),
+      local_accounts_subscription_(cros_settings_->AddSettingsObserver(
+          chromeos::kAccountsPrefDeviceLocalAccounts,
+          base::Bind(&DeviceLocalAccountPolicyService::
+                         UpdateAccountListIfNonePending,
+                     base::Unretained(this)))),
+      weak_factory_(this) {
   UpdateAccountList();
 }
 
@@ -173,7 +202,8 @@ void DeviceLocalAccountPolicyService::Connect(
   // Connect the brokers.
   for (PolicyBrokerMap::iterator it(policy_brokers_.begin());
        it != policy_brokers_.end(); ++it) {
-    it->second.ConnectIfPossible();
+    it->second->ConnectIfPossible(device_settings_service_,
+                                  device_management_service_);
   }
 }
 
@@ -184,7 +214,7 @@ void DeviceLocalAccountPolicyService::Disconnect() {
   // Disconnect the brokers.
   for (PolicyBrokerMap::iterator it(policy_brokers_.begin());
        it != policy_brokers_.end(); ++it) {
-    it->second.Disconnect();
+    it->second->Disconnect();
   }
 }
 
@@ -195,7 +225,7 @@ DeviceLocalAccountPolicyBroker*
   if (entry == policy_brokers_.end())
     return NULL;
 
-  return entry->second.GetBroker();
+  return entry->second;
 }
 
 bool DeviceLocalAccountPolicyService::IsPolicyAvailableForUser(
@@ -229,52 +259,214 @@ void DeviceLocalAccountPolicyService::OnStoreError(CloudPolicyStore* store) {
   FOR_EACH_OBSERVER(Observer, observers_, OnPolicyUpdated(broker->user_id()));
 }
 
+bool DeviceLocalAccountPolicyService::IsExtensionCacheDirectoryBusy(
+    const std::string& account_id) {
+  return busy_extension_cache_directories_.find(account_id) !=
+            busy_extension_cache_directories_.end();
+}
+
+void DeviceLocalAccountPolicyService::StartExtensionCachesIfPossible() {
+  for (PolicyBrokerMap::iterator it = policy_brokers_.begin();
+       it != policy_brokers_.end(); ++it) {
+    if (!it->second->extension_loader()->IsCacheRunning() &&
+        !IsExtensionCacheDirectoryBusy(it->second->account_id())) {
+      it->second->extension_loader()->StartCache(extension_cache_task_runner_);
+    }
+  }
+}
+
+bool DeviceLocalAccountPolicyService::StartExtensionCacheForAccountIfPresent(
+    const std::string& account_id) {
+  for (PolicyBrokerMap::iterator it = policy_brokers_.begin();
+       it != policy_brokers_.end(); ++it) {
+    if (it->second->account_id() == account_id) {
+      DCHECK(!it->second->extension_loader()->IsCacheRunning());
+      it->second->extension_loader()->StartCache(extension_cache_task_runner_);
+      return true;
+    }
+  }
+  return false;
+}
+
+void DeviceLocalAccountPolicyService::OnOrphanedExtensionCachesDeleted() {
+  DCHECK_EQ(IN_PROGRESS, orphan_cache_deletion_state_);
+
+  orphan_cache_deletion_state_ = DONE;
+  StartExtensionCachesIfPossible();
+}
+
+void DeviceLocalAccountPolicyService::OnObsoleteExtensionCacheShutdown(
+    const std::string& account_id) {
+  DCHECK_NE(NOT_STARTED, orphan_cache_deletion_state_);
+  DCHECK(IsExtensionCacheDirectoryBusy(account_id));
+
+  // The account with |account_id| was deleted and the broker for it has shut
+  // down completely.
+
+  if (StartExtensionCacheForAccountIfPresent(account_id)) {
+    // If another account with the same ID was created in the meantime, its
+    // extension cache is started, reusing the cache directory. The directory no
+    // longer needs to be marked as busy in this case.
+    busy_extension_cache_directories_.erase(account_id);
+    return;
+  }
+
+  // If no account with |account_id| exists anymore, the cache directory should
+  // be removed. The directory must stay marked as busy while the removal is in
+  // progress.
+  extension_cache_task_runner_->PostTaskAndReply(
+      FROM_HERE,
+      base::Bind(&DeleteObsoleteExtensionCache, account_id),
+      base::Bind(&DeviceLocalAccountPolicyService::
+                     OnObsoleteExtensionCacheDeleted,
+                 weak_factory_.GetWeakPtr(),
+                 account_id));
+}
+
+void DeviceLocalAccountPolicyService::OnObsoleteExtensionCacheDeleted(
+    const std::string& account_id) {
+  DCHECK_EQ(DONE, orphan_cache_deletion_state_);
+  DCHECK(IsExtensionCacheDirectoryBusy(account_id));
+
+  // The cache directory for |account_id| has been deleted. The directory no
+  // longer needs to be marked as busy.
+  busy_extension_cache_directories_.erase(account_id);
+
+  // If another account with the same ID was created in the meantime, start its
+  // extension cache, creating a new cache directory.
+  StartExtensionCacheForAccountIfPresent(account_id);
+}
+
 void DeviceLocalAccountPolicyService::UpdateAccountListIfNonePending() {
   // Avoid unnecessary calls to UpdateAccountList(): If an earlier call is still
   // pending (because the |cros_settings_| are not trusted yet), the updated
   // account list will be processed by that call when it eventually runs.
-  if (!cros_settings_callback_factory_.HasWeakPtrs())
+  if (!waiting_for_cros_settings_)
     UpdateAccountList();
 }
 
 void DeviceLocalAccountPolicyService::UpdateAccountList() {
-  if (chromeos::CrosSettingsProvider::TRUSTED !=
-          cros_settings_->PrepareTrustedValues(
-              base::Bind(&DeviceLocalAccountPolicyService::UpdateAccountList,
-                         cros_settings_callback_factory_.GetWeakPtr()))) {
-    return;
+  chromeos::CrosSettingsProvider::TrustedStatus status =
+      cros_settings_->PrepareTrustedValues(
+          base::Bind(&DeviceLocalAccountPolicyService::UpdateAccountList,
+                     weak_factory_.GetWeakPtr()));
+  switch (status) {
+    case chromeos::CrosSettingsProvider::TRUSTED:
+      waiting_for_cros_settings_ = false;
+      break;
+    case chromeos::CrosSettingsProvider::TEMPORARILY_UNTRUSTED:
+      waiting_for_cros_settings_ = true;
+      return;
+    case chromeos::CrosSettingsProvider::PERMANENTLY_UNTRUSTED:
+      waiting_for_cros_settings_ = false;
+      return;
   }
 
   // Update |policy_brokers_|, keeping existing entries.
   PolicyBrokerMap old_policy_brokers;
   policy_brokers_.swap(old_policy_brokers);
+  std::set<std::string> subdirectories_to_keep;
   const std::vector<DeviceLocalAccount> device_local_accounts =
       GetDeviceLocalAccounts(cros_settings_);
   for (std::vector<DeviceLocalAccount>::const_iterator it =
            device_local_accounts.begin();
        it != device_local_accounts.end(); ++it) {
-    PolicyBrokerWrapper& wrapper = policy_brokers_[it->user_id];
-    wrapper.user_id = it->user_id;
-    wrapper.account_id = it->account_id;
-    wrapper.parent = this;
-
-    // Reuse the existing broker if present.
-    PolicyBrokerWrapper& existing_wrapper = old_policy_brokers[it->user_id];
-    wrapper.broker = existing_wrapper.broker;
-    existing_wrapper.broker = NULL;
+    PolicyBrokerMap::iterator broker_it = old_policy_brokers.find(it->user_id);
+
+    scoped_ptr<DeviceLocalAccountPolicyBroker> broker;
+    bool broker_initialized = false;
+    if (broker_it != old_policy_brokers.end()) {
+      // Reuse the existing broker if present.
+      broker.reset(broker_it->second);
+      old_policy_brokers.erase(broker_it);
+      broker_initialized = true;
+    } else {
+      scoped_ptr<DeviceLocalAccountPolicyStore> store(
+          new DeviceLocalAccountPolicyStore(it->account_id,
+                                            session_manager_client_,
+                                            device_settings_service_,
+                                            store_background_task_runner_));
+      store->AddObserver(this);
+      broker.reset(new DeviceLocalAccountPolicyBroker(
+          *it,
+          store.Pass(),
+          base::MessageLoopProxy::current()));
+    }
 
     // Fire up the cloud connection for fetching policy for the account from
     // the cloud if this is an enterprise-managed device.
-    wrapper.ConnectIfPossible();
+    broker->ConnectIfPossible(device_settings_service_,
+                              device_management_service_);
+
+    policy_brokers_[it->user_id] = broker.release();
+    if (!broker_initialized) {
+      // The broker must be initialized after it has been added to
+      // |policy_brokers_|.
+      policy_brokers_[it->user_id]->Initialize();
+    }
+
+    if (orphan_cache_deletion_state_ == NOT_STARTED) {
+      subdirectories_to_keep.insert(
+          GetCacheSubdirectoryForAccountID(it->account_id));
+    }
+  }
+
+  std::set<std::string> obsolete_account_ids;
+  for (PolicyBrokerMap::const_iterator it = old_policy_brokers.begin();
+       it != old_policy_brokers.end(); ++it) {
+    obsolete_account_ids.insert(it->second->account_id());
+  }
+
+  if (orphan_cache_deletion_state_ == NOT_STARTED) {
+    DCHECK(old_policy_brokers.empty());
+    DCHECK(busy_extension_cache_directories_.empty());
+
+    // If this method is running for the first time, no extension caches have
+    // been started yet. Take this opportunity to do a clean-up by removing
+    // orphaned cache directories not found in |subdirectories_to_keep| from the
+    // cache directory.
+    orphan_cache_deletion_state_ = IN_PROGRESS;
+    extension_cache_task_runner_->PostTaskAndReply(
+        FROM_HERE,
+        base::Bind(&DeleteOrphanedExtensionCaches, subdirectories_to_keep),
+        base::Bind(&DeviceLocalAccountPolicyService::
+                       OnOrphanedExtensionCachesDeleted,
+                   weak_factory_.GetWeakPtr()));
+
+    // Start the extension caches for all brokers. These belong to accounts in
+    // |account_ids| and are not affected by the clean-up.
+    StartExtensionCachesIfPossible();
+  } else {
+    // If this method has run before, obsolete brokers may exist. Shut down
+    // their extension caches and delete the brokers.
+    DeleteBrokers(&old_policy_brokers);
+
+    if (orphan_cache_deletion_state_ == DONE) {
+      // If the initial clean-up of orphaned cache directories has been
+      // complete, start any extension caches that are not running yet but can
+      // be started now because their cache directories are not busy.
+      StartExtensionCachesIfPossible();
+    }
   }
-  DeleteBrokers(&old_policy_brokers);
 
   FOR_EACH_OBSERVER(Observer, observers_, OnDeviceLocalAccountsChanged());
 }
 
 void DeviceLocalAccountPolicyService::DeleteBrokers(PolicyBrokerMap* map) {
-  for (PolicyBrokerMap::iterator it = map->begin(); it != map->end(); ++it)
-    it->second.DeleteBroker();
+  for (PolicyBrokerMap::iterator it = map->begin(); it != map->end(); ++it) {
+    it->second->core()->store()->RemoveObserver(this);
+    scoped_refptr<chromeos::DeviceLocalAccountExternalPolicyLoader>
+        extension_loader = it->second->extension_loader();
+    if (extension_loader->IsCacheRunning()) {
+      DCHECK(!IsExtensionCacheDirectoryBusy(it->second->account_id()));
+      busy_extension_cache_directories_.insert(it->second->account_id());
+      extension_loader->StopCache(base::Bind(
+          &DeviceLocalAccountPolicyService::OnObsoleteExtensionCacheShutdown,
+          weak_factory_.GetWeakPtr(),
+          it->second->account_id()));
+    }
+    delete it->second;
+  }
   map->clear();
 }
 
@@ -283,8 +475,8 @@ DeviceLocalAccountPolicyBroker*
         CloudPolicyStore* store) {
   for (PolicyBrokerMap::iterator it(policy_brokers_.begin());
        it != policy_brokers_.end(); ++it) {
-    if (it->second.broker && it->second.broker->core()->store() == store)
-      return it->second.broker;
+    if (it->second->core()->store() == store)
+      return it->second;
   }
   return NULL;
 }