Make largest_changestamp setter/getter asynchronous.

BUG=147299
TEST=unit tests

Review URL: https://chromiumcodereview.appspot.com/11876002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@177091 0039d316-1c4b-4281-b951-d872f2087c98

11 files changed, 150 insertions, 25 deletions

diff --git a/chrome/browser/chromeos/drive/drive_feed_loader.cc b/chrome/browser/chromeos/drive/drive_feed_loader.cc
index 8c73be6..b428eee 100644
--- a/chrome/browser/chromeos/drive/drive_feed_loader.cc
+++ b/chrome/browser/chromeos/drive/drive_feed_loader.cc
@@ -256,9 +256,6 @@ void DriveFeedLoader::ReloadFromServerIfNeeded(
     const FileOperationCallback& callback) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   DCHECK(!callback.is_null());
-  DVLOG(1) << "ReloadFromServerIfNeeded local_changestamp="
-           << resource_metadata_->largest_changestamp()
-           << ", loaded=" << resource_metadata_->loaded();
 
   // Sets the refreshing flag, so that the caller does not send refresh requests
   // in parallel (see DriveFileSystem::CheckForUpdates). Corresponding
@@ -291,9 +288,7 @@ void DriveFeedLoader::OnGetAccountMetadata(
   DCHECK(!callback.is_null());
   DCHECK(refreshing_);
 
-  int64 local_changestamp = resource_metadata_->largest_changestamp();
   int64 remote_changestamp = 0;
-
   // When account metadata successfully fetched, parse the latest changestamp.
   if (util::GDataToDriveFileError(status) == DRIVE_FILE_OK) {
     DCHECK(account_metadata);
@@ -301,6 +296,21 @@ void DriveFeedLoader::OnGetAccountMetadata(
     remote_changestamp = account_metadata->largest_changestamp();
   }
 
+  resource_metadata_->GetLargestChangestamp(
+      base::Bind(&DriveFeedLoader::CompareChangestampsAndLoadIfNeeded,
+                 weak_ptr_factory_.GetWeakPtr(),
+                 callback,
+                 remote_changestamp));
+}
+
+void DriveFeedLoader::CompareChangestampsAndLoadIfNeeded(
+    const FileOperationCallback& callback,
+    int64 remote_changestamp,
+    int64 local_changestamp) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  DCHECK(!callback.is_null());
+  DCHECK(refreshing_);
+
   if (remote_changestamp > 0 && local_changestamp >= remote_changestamp) {
     if (local_changestamp > remote_changestamp) {
       LOG(WARNING) << "Cached client feed is fresher than server, client = "
diff --git a/chrome/browser/chromeos/drive/drive_feed_loader.h b/chrome/browser/chromeos/drive/drive_feed_loader.h
index 95d986a..9292f07 100644
--- a/chrome/browser/chromeos/drive/drive_feed_loader.h
+++ b/chrome/browser/chromeos/drive/drive_feed_loader.h
@@ -119,6 +119,14 @@ class DriveFeedLoader {
       google_apis::GDataErrorCode status,
       scoped_ptr<google_apis::AccountMetadataFeed> account_metadata);
 
+  // Callback for DriveResourceMetadata::GetLargestChangestamp.
+  // Compares |remote_changestamp| and |local_changestamp| and triggers
+  // LoadFromServer if necessary.
+  void CompareChangestampsAndLoadIfNeeded(
+      const FileOperationCallback& callback,
+      int64 remote_changestamp,
+      int64 local_changestamp);
+
   // Callback for handling response from |DriveAPIService::GetApplicationInfo|.
   // If the application list is successfully parsed, passes the list to
   // Drive webapps registry.
diff --git a/chrome/browser/chromeos/drive/drive_feed_processor.cc b/chrome/browser/chromeos/drive/drive_feed_processor.cc
index b2c2915..22746ea 100644
--- a/chrome/browser/chromeos/drive/drive_feed_processor.cc
+++ b/chrome/browser/chromeos/drive/drive_feed_processor.cc
@@ -17,6 +17,21 @@ using content::BrowserThread;
 
 namespace drive {
 
+namespace {
+
+// Callback for DriveResourceMetadata::SetLargestChangestamp.
+// Runs |on_complete_callback|. |on_complete_callback| must not be null.
+void RunOnCompleteCallback(const base::Closure& on_complete_callback,
+                           DriveFileError error) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  DCHECK(!on_complete_callback.is_null());
+  DCHECK_EQ(DRIVE_FILE_OK, error);
+
+  on_complete_callback.Run();
+}
+
+}  // namespace
+
 class DriveFeedProcessor::FeedToEntryProtoMapUMAStats {
  public:
   FeedToEntryProtoMapUMAStats()
@@ -382,11 +397,11 @@ void DriveFeedProcessor::OnUpdateRootUploadUrl(
 
 void DriveFeedProcessor::OnComplete() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  DCHECK(!on_complete_callback_.is_null());
 
   resource_metadata_->set_loaded(true);
-  resource_metadata_->set_largest_changestamp(largest_changestamp_);
-  on_complete_callback_.Run();
+  resource_metadata_->SetLargestChangestamp(
+      largest_changestamp_,
+      base::Bind(&RunOnCompleteCallback, on_complete_callback_));
 }
 
 void DriveFeedProcessor::Clear() {
diff --git a/chrome/browser/chromeos/drive/drive_file_system.cc b/chrome/browser/chromeos/drive/drive_file_system.cc
index 4e4b6d4..a7953da 100644
--- a/chrome/browser/chromeos/drive/drive_file_system.cc
+++ b/chrome/browser/chromeos/drive/drive_file_system.cc
@@ -153,6 +153,19 @@ void RunGetEntryInfoWithFilePathCallback(
   callback.Run(error, path, entry_proto.Pass());
 }
 
+// Callback for DriveResourceMetadata::GetLargestChangestamp.
+// |callback| must not be null.
+void OnGetLargestChangestamp(
+    DriveFileSystemMetadata metadata,  // Will be modified.
+    const GetFilesystemMetadataCallback& callback,
+    int64 largest_changestamp) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  DCHECK(!callback.is_null());
+
+  metadata.largest_changestamp = largest_changestamp;
+  callback.Run(metadata);
+}
+
 }  // namespace
 
 // DriveFileSystem::FindFirstMissingParentDirectoryParams implementation.
@@ -1781,9 +1794,12 @@ void DriveFileSystem::AddUploadedFileToCache(
                 params.callback);
 }
 
-DriveFileSystemMetadata DriveFileSystem::GetMetadata() const {
+void DriveFileSystem::GetMetadata(
+    const GetFilesystemMetadataCallback& callback) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  DCHECK(!callback.is_null());
+
   DriveFileSystemMetadata metadata;
-  metadata.largest_changestamp = resource_metadata_->largest_changestamp();
   metadata.loaded = resource_metadata_->loaded();
   metadata.refreshing = feed_loader_->refreshing();
 
@@ -1793,7 +1809,8 @@ DriveFileSystemMetadata DriveFileSystem::GetMetadata() const {
   metadata.last_update_check_time = last_update_check_time_;
   metadata.last_update_check_error = last_update_check_error_;
 
-  return metadata;
+  resource_metadata_->GetLargestChangestamp(
+      base::Bind(&OnGetLargestChangestamp, metadata, callback));
 }
 
 void DriveFileSystem::OnDisableDriveHostedFilesChanged() {
diff --git a/chrome/browser/chromeos/drive/drive_file_system.h b/chrome/browser/chromeos/drive/drive_file_system.h
index 6aa48c0..987931f 100644
--- a/chrome/browser/chromeos/drive/drive_file_system.h
+++ b/chrome/browser/chromeos/drive/drive_file_system.h
@@ -134,7 +134,8 @@ class DriveFileSystem : public DriveFileSystemInterface,
                                scoped_ptr<google_apis::ResourceEntry> doc_entry,
                                const FilePath& file_content_path,
                                const FileOperationCallback& callback) OVERRIDE;
-  virtual DriveFileSystemMetadata GetMetadata() const OVERRIDE;
+  virtual void GetMetadata(
+      const GetFilesystemMetadataCallback& callback) OVERRIDE;
   virtual void Reload() OVERRIDE;
 
   // file_system::OperationObserver overrides.
diff --git a/chrome/browser/chromeos/drive/drive_file_system_interface.h b/chrome/browser/chromeos/drive/drive_file_system_interface.h
index 1d494ff..0a34a81 100644
--- a/chrome/browser/chromeos/drive/drive_file_system_interface.h
+++ b/chrome/browser/chromeos/drive/drive_file_system_interface.h
@@ -72,6 +72,10 @@ typedef base::Callback<void(DriveFileError error,
                             int64 bytes_total,
                             int64 bytes_used)> GetAvailableSpaceCallback;
 
+// Used to get drive filesystem metadata.
+typedef base::Callback<void(const DriveFileSystemMetadata&)>
+    GetFilesystemMetadataCallback;
+
 // Drive file system abstraction layer.
 // The interface is defined to make DriveFileSystem mockable.
 class DriveFileSystemInterface {
@@ -341,8 +345,9 @@ class DriveFileSystemInterface {
                                const FileOperationCallback& callback) = 0;
 
   // Returns miscellaneous metadata of the file system like the largest
-  // timestamp. Used in chrome:drive-internals.
-  virtual DriveFileSystemMetadata GetMetadata() const = 0;
+  // timestamp. Used in chrome:drive-internals. |callback| must not be null.
+  virtual void GetMetadata(
+      const GetFilesystemMetadataCallback& callback) = 0;
 
   // Reloads the file system feeds from the server.
   virtual void Reload() = 0;
diff --git a/chrome/browser/chromeos/drive/drive_resource_metadata.cc b/chrome/browser/chromeos/drive/drive_resource_metadata.cc
index c5ca213..2fbc048 100644
--- a/chrome/browser/chromeos/drive/drive_resource_metadata.cc
+++ b/chrome/browser/chromeos/drive/drive_resource_metadata.cc
@@ -230,6 +230,20 @@ void DriveResourceMetadata::ClearRoot() {
   root_.reset();
 }
 
+void DriveResourceMetadata::GetLargestChangestamp(
+    const GetChangestampCallback& callback) {
+  base::MessageLoopProxy::current()->PostTask(
+      FROM_HERE, base::Bind(callback, largest_changestamp_));
+}
+
+void DriveResourceMetadata::SetLargestChangestamp(
+    int64 value,
+    const FileOperationCallback& callback) {
+  largest_changestamp_ = value;
+  base::MessageLoopProxy::current()->PostTask(
+      FROM_HERE, base::Bind(callback, DRIVE_FILE_OK));
+}
+
 void DriveResourceMetadata::AddEntryToDirectory(
     const FilePath& directory_path,
     scoped_ptr<google_apis::ResourceEntry> entry,
diff --git a/chrome/browser/chromeos/drive/drive_resource_metadata.h b/chrome/browser/chromeos/drive/drive_resource_metadata.h
index 052c45d..3ee5cad 100644
--- a/chrome/browser/chromeos/drive/drive_resource_metadata.h
+++ b/chrome/browser/chromeos/drive/drive_resource_metadata.h
@@ -90,6 +90,8 @@ typedef base::Callback<void(DriveFileError error,
 typedef base::Callback<void(const std::set<FilePath>&)>
     GetChildDirectoriesCallback;
 
+typedef base::Callback<void(int64)> GetChangestampCallback;
+
 // This is a part of EntryInfoPairResult.
 struct EntryInfoResult {
   EntryInfoResult();
@@ -132,15 +134,16 @@ class DriveResourceMetadata {
   size_t serialized_size() const { return serialized_size_; }
   void set_serialized_size(size_t size) { serialized_size_ = size; }
 
-  // Largest change timestamp that was the source of content for the current
-  // state of the root directory.
-  int64 largest_changestamp() const { return largest_changestamp_; }
-  void set_largest_changestamp(int64 value) { largest_changestamp_ = value; }
-
   // True if the file system feed is loaded from the cache or from the server.
   bool loaded() const { return loaded_; }
   void set_loaded(bool loaded) { loaded_ = loaded; }
 
+  // Largest change timestamp that was the source of content for the current
+  // state of the root directory.
+  void GetLargestChangestamp(const GetChangestampCallback& callback);
+  void SetLargestChangestamp(int64 value,
+                             const FileOperationCallback& callback);
+
   // Add |entry| to directory with path |directory_path| and invoke the
   // callback asynchronously.
   // |callback| must not be null.
diff --git a/chrome/browser/chromeos/drive/drive_resource_metadata_unittest.cc b/chrome/browser/chromeos/drive/drive_resource_metadata_unittest.cc
index 3459c1e..5ccce25 100644
--- a/chrome/browser/chromeos/drive/drive_resource_metadata_unittest.cc
+++ b/chrome/browser/chromeos/drive/drive_resource_metadata_unittest.cc
@@ -34,12 +34,19 @@ void CopyResultsFromInitFromDBCallback(DriveFileError* expected_error,
   *expected_error = actual_error;
 }
 
+// Copies result from GetChildDirectoriesCallback.
 void CopyResultFromGetChildDirectoriesCallback(
     std::set<FilePath>* out_child_directories,
     const std::set<FilePath>& in_child_directories) {
   *out_child_directories = in_child_directories;
 }
 
+// Copies result from GetChangestampCallback.
+void CopyResultFromGetChangestampCallback(
+    int64* out_changestamp, int64 in_changestamp) {
+  *out_changestamp = in_changestamp;
+}
+
 }  // namespace
 
 class DriveResourceMetadataTest : public testing::Test {
@@ -180,6 +187,26 @@ TEST_F(DriveResourceMetadataTest, VersionCheck) {
   ASSERT_FALSE(resource_metadata.ParseFromString(serialized_proto));
 }
 
+TEST_F(DriveResourceMetadataTest, LargestChangestamp) {
+  DriveResourceMetadata resource_metadata;
+
+  int64 in_changestamp = 123456;
+  DriveFileError error = DRIVE_FILE_ERROR_FAILED;
+  resource_metadata.SetLargestChangestamp(
+      in_changestamp,
+      base::Bind(&test_util::CopyErrorCodeFromFileOperationCallback,
+                 &error));
+  google_apis::test_util::RunBlockingPoolTask();
+  EXPECT_EQ(DRIVE_FILE_OK, error);
+
+  int64 out_changestamp = 0;
+  resource_metadata.GetLargestChangestamp(
+      base::Bind(&CopyResultFromGetChangestampCallback,
+                 &out_changestamp));
+  google_apis::test_util::RunBlockingPoolTask();
+  DCHECK_EQ(in_changestamp, out_changestamp);
+}
+
 TEST_F(DriveResourceMetadataTest, GetEntryByResourceId_RootDirectory) {
   DriveResourceMetadata resource_metadata;
 
diff --git a/chrome/browser/chromeos/drive/mock_drive_file_system.h b/chrome/browser/chromeos/drive/mock_drive_file_system.h
index 44a3800..2f116eb 100644
--- a/chrome/browser/chromeos/drive/mock_drive_file_system.h
+++ b/chrome/browser/chromeos/drive/mock_drive_file_system.h
@@ -97,7 +97,8 @@ class MockDriveFileSystem : public DriveFileSystemInterface {
                                const FilePath& file_content_path,
                                const FileOperationCallback& callback) OVERRIDE {
   }
-  MOCK_CONST_METHOD0(GetMetadata, DriveFileSystemMetadata());
+  MOCK_METHOD1(GetMetadata,
+               void(const GetFilesystemMetadataCallback& callback));
   MOCK_METHOD0(Reload, void());
 };
 
diff --git a/chrome/browser/ui/webui/chromeos/drive_internals_ui.cc b/chrome/browser/ui/webui/chromeos/drive_internals_ui.cc
index ce44f40..508dcee 100644
--- a/chrome/browser/ui/webui/chromeos/drive_internals_ui.cc
+++ b/chrome/browser/ui/webui/chromeos/drive_internals_ui.cc
@@ -235,6 +235,14 @@ class DriveInternalsWebUIHandler : public content::WebUIMessageHandler {
       google_apis::GDataErrorCode status,
       scoped_ptr<google_apis::AccountMetadataFeed> account_metadata);
 
+  // Callback for DriveFilesystem::GetMetadata for local update.
+  void OnGetFilesystemMetadataForLocal(
+      const drive::DriveFileSystemMetadata& metadata);
+
+  // Callback for DriveFilesystem::GetMetadata for local update.
+  void OnGetFilesystemMetadataForDeltaUpdate(
+      const drive::DriveFileSystemMetadata& metadata);
+
   // Called when the page requests periodic update.
   void OnPeriodicUpdate(const base::ListValue* args);
 
@@ -401,11 +409,18 @@ void DriveInternalsWebUIHandler::UpdateAccountMetadataSection(
 
 void DriveInternalsWebUIHandler::UpdateLocalMetadataSection(
     google_apis::DriveServiceInterface* drive_service) {
-  DCHECK(drive_service);
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+
+  GetSystemService()->file_system()->GetMetadata(
+      base::Bind(&DriveInternalsWebUIHandler::OnGetFilesystemMetadataForLocal,
+                 weak_ptr_factory_.GetWeakPtr()));
+}
+
+void DriveInternalsWebUIHandler::OnGetFilesystemMetadataForLocal(
+    const drive::DriveFileSystemMetadata& metadata) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   base::DictionaryValue local_metadata;
-  const drive::DriveFileSystemMetadata metadata =
-      GetSystemService()->file_system()->GetMetadata();
   local_metadata.SetDouble("account-largest-changestamp-local",
                            metadata.largest_changestamp);
   local_metadata.SetBoolean("account-metadata-loaded", metadata.loaded);
@@ -414,8 +429,17 @@ void DriveInternalsWebUIHandler::UpdateLocalMetadataSection(
 }
 
 void DriveInternalsWebUIHandler::UpdateDeltaUpdateStatusSection() {
-  const drive::DriveFileSystemMetadata metadata =
-      GetSystemService()->file_system()->GetMetadata();
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+
+  GetSystemService()->file_system()->GetMetadata(
+      base::Bind(
+          &DriveInternalsWebUIHandler::OnGetFilesystemMetadataForDeltaUpdate,
+          weak_ptr_factory_.GetWeakPtr()));
+}
+
+void DriveInternalsWebUIHandler::OnGetFilesystemMetadataForDeltaUpdate(
+    const drive::DriveFileSystemMetadata& metadata) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   base::DictionaryValue delta_update_status;
   delta_update_status.SetBoolean("push-notification-enabled",