OBSOLETE: Move (most of) chrome/browser/chromeos/drive into components/drive.

chrome/browser/chromeos/drive/change_list_loader.cc

Index: chrome/browser/chromeos/drive/change_list_loader.cc
diff --git a/chrome/browser/chromeos/drive/change_list_loader.cc b/chrome/browser/chromeos/drive/change_list_loader.cc
deleted file mode 100644
index abe0fa4439fbcf304e25015bb258a152faad0006..0000000000000000000000000000000000000000
--- a/chrome/browser/chromeos/drive/change_list_loader.cc
+++ /dev/null
@@ -1,585 +0,0 @@
-// 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.
-
-#include "chrome/browser/chromeos/drive/change_list_loader.h"
-
-#include <set>
-
-#include "base/callback.h"
-#include "base/callback_helpers.h"
-#include "base/metrics/histogram.h"
-#include "base/strings/string_number_conversions.h"
-#include "base/synchronization/cancellation_flag.h"
-#include "base/thread_task_runner_handle.h"
-#include "base/time/time.h"
-#include "chrome/browser/chromeos/drive/change_list_loader_observer.h"
-#include "chrome/browser/chromeos/drive/change_list_processor.h"
-#include "chrome/browser/chromeos/drive/file_system_core_util.h"
-#include "chrome/browser/chromeos/drive/job_scheduler.h"
-#include "chrome/browser/chromeos/drive/resource_metadata.h"
-#include "components/drive/event_logger.h"
-#include "google_apis/drive/drive_api_parser.h"
-#include "url/gurl.h"
-
-namespace drive {
-namespace internal {
-
-typedef base::Callback<void(FileError, ScopedVector<ChangeList>)>
-    FeedFetcherCallback;
-
-class ChangeListLoader::FeedFetcher {
- public:
-  virtual ~FeedFetcher() {}
-  virtual void Run(const FeedFetcherCallback& callback) = 0;
-};
-
-namespace {
-
-// Fetches all the (currently available) resource entries from the server.
-class FullFeedFetcher : public ChangeListLoader::FeedFetcher {
- public:
-  explicit FullFeedFetcher(JobScheduler* scheduler)
-      : scheduler_(scheduler),
-        weak_ptr_factory_(this) {
-  }
-
-  ~FullFeedFetcher() override {}
-
-  void Run(const FeedFetcherCallback& callback) override {
-    DCHECK(thread_checker_.CalledOnValidThread());
-    DCHECK(!callback.is_null());
-
-    // Remember the time stamp for usage stats.
-    start_time_ = base::TimeTicks::Now();
-
-    // This is full resource list fetch.
-    scheduler_->GetAllFileList(
-        base::Bind(&FullFeedFetcher::OnFileListFetched,
-                   weak_ptr_factory_.GetWeakPtr(), callback));
-  }
-
- private:
-  void OnFileListFetched(const FeedFetcherCallback& callback,
-                         google_apis::DriveApiErrorCode status,
-                         scoped_ptr<google_apis::FileList> file_list) {
-    DCHECK(thread_checker_.CalledOnValidThread());
-    DCHECK(!callback.is_null());
-
-    FileError error = GDataToFileError(status);
-    if (error != FILE_ERROR_OK) {
-      callback.Run(error, ScopedVector<ChangeList>());
-      return;
-    }
-
-    DCHECK(file_list);
-    change_lists_.push_back(new ChangeList(*file_list));
-
-    if (!file_list->next_link().is_empty()) {
-      // There is the remaining result so fetch it.
-      scheduler_->GetRemainingFileList(
-          file_list->next_link(),
-          base::Bind(&FullFeedFetcher::OnFileListFetched,
-                     weak_ptr_factory_.GetWeakPtr(), callback));
-      return;
-    }
-
-    UMA_HISTOGRAM_LONG_TIMES("Drive.FullFeedLoadTime",
-                             base::TimeTicks::Now() - start_time_);
-
-    // Note: The fetcher is managed by ChangeListLoader, and the instance
-    // will be deleted in the callback. Do not touch the fields after this
-    // invocation.
-    callback.Run(FILE_ERROR_OK, change_lists_.Pass());
-  }
-
-  JobScheduler* scheduler_;
-  ScopedVector<ChangeList> change_lists_;
-  base::TimeTicks start_time_;
-  base::ThreadChecker thread_checker_;
-  base::WeakPtrFactory<FullFeedFetcher> weak_ptr_factory_;
-  DISALLOW_COPY_AND_ASSIGN(FullFeedFetcher);
-};
-
-// Fetches the delta changes since |start_change_id|.
-class DeltaFeedFetcher : public ChangeListLoader::FeedFetcher {
- public:
-  DeltaFeedFetcher(JobScheduler* scheduler, int64 start_change_id)
-      : scheduler_(scheduler),
-        start_change_id_(start_change_id),
-        weak_ptr_factory_(this) {
-  }
-
-  ~DeltaFeedFetcher() override {}
-
-  void Run(const FeedFetcherCallback& callback) override {
-    DCHECK(thread_checker_.CalledOnValidThread());
-    DCHECK(!callback.is_null());
-
-    scheduler_->GetChangeList(
-        start_change_id_,
-        base::Bind(&DeltaFeedFetcher::OnChangeListFetched,
-                   weak_ptr_factory_.GetWeakPtr(), callback));
-  }
-
- private:
-  void OnChangeListFetched(const FeedFetcherCallback& callback,
-                           google_apis::DriveApiErrorCode status,
-                           scoped_ptr<google_apis::ChangeList> change_list) {
-    DCHECK(thread_checker_.CalledOnValidThread());
-    DCHECK(!callback.is_null());
-
-    FileError error = GDataToFileError(status);
-    if (error != FILE_ERROR_OK) {
-      callback.Run(error, ScopedVector<ChangeList>());
-      return;
-    }
-
-    DCHECK(change_list);
-    change_lists_.push_back(new ChangeList(*change_list));
-
-    if (!change_list->next_link().is_empty()) {
-      // There is the remaining result so fetch it.
-      scheduler_->GetRemainingChangeList(
-          change_list->next_link(),
-          base::Bind(&DeltaFeedFetcher::OnChangeListFetched,
-                     weak_ptr_factory_.GetWeakPtr(), callback));
-      return;
-    }
-
-    // Note: The fetcher is managed by ChangeListLoader, and the instance
-    // will be deleted in the callback. Do not touch the fields after this
-    // invocation.
-    callback.Run(FILE_ERROR_OK, change_lists_.Pass());
-  }
-
-  JobScheduler* scheduler_;
-  int64 start_change_id_;
-  ScopedVector<ChangeList> change_lists_;
-  base::ThreadChecker thread_checker_;
-  base::WeakPtrFactory<DeltaFeedFetcher> weak_ptr_factory_;
-  DISALLOW_COPY_AND_ASSIGN(DeltaFeedFetcher);
-};
-
-}  // namespace
-
-LoaderController::LoaderController()
-    : lock_count_(0),
-      weak_ptr_factory_(this) {
-}
-
-LoaderController::~LoaderController() {
-  DCHECK(thread_checker_.CalledOnValidThread());
-}
-
-scoped_ptr<base::ScopedClosureRunner> LoaderController::GetLock() {
-  DCHECK(thread_checker_.CalledOnValidThread());
-
-  ++lock_count_;
-  return make_scoped_ptr(new base::ScopedClosureRunner(
-      base::Bind(&LoaderController::Unlock,
-                 weak_ptr_factory_.GetWeakPtr())));
-}
-
-void LoaderController::ScheduleRun(const base::Closure& task) {
-  DCHECK(thread_checker_.CalledOnValidThread());
-  DCHECK(!task.is_null());
-
-  if (lock_count_ > 0) {
-    pending_tasks_.push_back(task);
-  } else {
-    task.Run();
-  }
-}
-
-void LoaderController::Unlock() {
-  DCHECK(thread_checker_.CalledOnValidThread());
-  DCHECK_LT(0, lock_count_);
-
-  if (--lock_count_ > 0)
-    return;
-
-  std::vector<base::Closure> tasks;
-  tasks.swap(pending_tasks_);
-  for (size_t i = 0; i < tasks.size(); ++i)
-    tasks[i].Run();
-}
-
-AboutResourceLoader::AboutResourceLoader(JobScheduler* scheduler)
-    : scheduler_(scheduler),
-      current_update_task_id_(-1),
-      weak_ptr_factory_(this) {
-}
-
-AboutResourceLoader::~AboutResourceLoader() {}
-
-void AboutResourceLoader::GetAboutResource(
-    const google_apis::AboutResourceCallback& callback) {
-  DCHECK(thread_checker_.CalledOnValidThread());
-  DCHECK(!callback.is_null());
-
-  // If the latest UpdateAboutResource task is still running. Wait for it,
-  if (pending_callbacks_.count(current_update_task_id_)) {
-    pending_callbacks_[current_update_task_id_].push_back(callback);
-    return;
-  }
-
-  if (cached_about_resource_) {
-    base::ThreadTaskRunnerHandle::Get()->PostTask(
-        FROM_HERE,
-        base::Bind(
-            callback,
-            google_apis::HTTP_NO_CONTENT,
-            base::Passed(scoped_ptr<google_apis::AboutResource>(
-                new google_apis::AboutResource(*cached_about_resource_)))));
-  } else {
-    UpdateAboutResource(callback);
-  }
-}
-
-void AboutResourceLoader::UpdateAboutResource(
-    const google_apis::AboutResourceCallback& callback) {
-  DCHECK(thread_checker_.CalledOnValidThread());
-  DCHECK(!callback.is_null());
-
-  ++current_update_task_id_;
-  pending_callbacks_[current_update_task_id_].push_back(callback);
-
-  scheduler_->GetAboutResource(
-      base::Bind(&AboutResourceLoader::UpdateAboutResourceAfterGetAbout,
-                 weak_ptr_factory_.GetWeakPtr(),
-                 current_update_task_id_));
-}
-
-void AboutResourceLoader::UpdateAboutResourceAfterGetAbout(
-    int task_id,
-    google_apis::DriveApiErrorCode status,
-    scoped_ptr<google_apis::AboutResource> about_resource) {
-  DCHECK(thread_checker_.CalledOnValidThread());
-  FileError error = GDataToFileError(status);
-
-  const std::vector<google_apis::AboutResourceCallback> callbacks =
-      pending_callbacks_[task_id];
-  pending_callbacks_.erase(task_id);
-
-  if (error != FILE_ERROR_OK) {
-    for (size_t i = 0; i < callbacks.size(); ++i)
-      callbacks[i].Run(status, scoped_ptr<google_apis::AboutResource>());
-    return;
-  }
-
-  // Updates the cache when the resource is successfully obtained.
-  if (cached_about_resource_ &&
-      cached_about_resource_->largest_change_id() >
-      about_resource->largest_change_id()) {
-    LOG(WARNING) << "Local cached about resource is fresher than server, "
-                 << "local = " << cached_about_resource_->largest_change_id()
-                 << ", server = " << about_resource->largest_change_id();
-  }
-  cached_about_resource_.reset(new google_apis::AboutResource(*about_resource));
-
-  for (size_t i = 0; i < callbacks.size(); ++i) {
-    callbacks[i].Run(
-        status,
-        make_scoped_ptr(new google_apis::AboutResource(*about_resource)));
-  }
-}
-
-ChangeListLoader::ChangeListLoader(
-    EventLogger* logger,
-    base::SequencedTaskRunner* blocking_task_runner,
-    ResourceMetadata* resource_metadata,
-    JobScheduler* scheduler,
-    AboutResourceLoader* about_resource_loader,
-    LoaderController* loader_controller)
-    : logger_(logger),
-      blocking_task_runner_(blocking_task_runner),
-      in_shutdown_(new base::CancellationFlag),
-      resource_metadata_(resource_metadata),
-      scheduler_(scheduler),
-      about_resource_loader_(about_resource_loader),
-      loader_controller_(loader_controller),
-      loaded_(false),
-      weak_ptr_factory_(this) {
-}
-
-ChangeListLoader::~ChangeListLoader() {
-  in_shutdown_->Set();
-  // Delete |in_shutdown_| with the blocking task runner so that it gets deleted
-  // after all active ChangeListProcessors.
-  blocking_task_runner_->DeleteSoon(FROM_HERE, in_shutdown_.release());
-}
-
-bool ChangeListLoader::IsRefreshing() const {
-  // Callback for change list loading is stored in pending_load_callback_.
-  // It is non-empty if and only if there is an in-flight loading operation.
-  return !pending_load_callback_.empty();
-}
-
-void ChangeListLoader::AddObserver(ChangeListLoaderObserver* observer) {
-  DCHECK(thread_checker_.CalledOnValidThread());
-  observers_.AddObserver(observer);
-}
-
-void ChangeListLoader::RemoveObserver(ChangeListLoaderObserver* observer) {
-  DCHECK(thread_checker_.CalledOnValidThread());
-  observers_.RemoveObserver(observer);
-}
-
-void ChangeListLoader::CheckForUpdates(const FileOperationCallback& callback) {
-  DCHECK(thread_checker_.CalledOnValidThread());
-  DCHECK(!callback.is_null());
-
-  // We only start to check for updates iff the load is done.
-  // I.e., we ignore checking updates if not loaded to avoid starting the
-  // load without user's explicit interaction (such as opening Drive).
-  if (!loaded_ && !IsRefreshing())
-    return;
-
-  // For each CheckForUpdates() request, always refresh the changestamp info.
-  about_resource_loader_->UpdateAboutResource(
-      base::Bind(&ChangeListLoader::OnAboutResourceUpdated,
-                 weak_ptr_factory_.GetWeakPtr()));
-
-  if (IsRefreshing()) {
-    // There is in-flight loading. So keep the callback here, and check for
-    // updates when the in-flight loading is completed.
-    pending_update_check_callback_ = callback;
-    return;
-  }
-
-  DCHECK(loaded_);
-  logger_->Log(logging::LOG_INFO, "Checking for updates");
-  Load(callback);
-}
-
-void ChangeListLoader::LoadIfNeeded(const FileOperationCallback& callback) {
-  DCHECK(thread_checker_.CalledOnValidThread());
-  DCHECK(!callback.is_null());
-
-  // If the metadata is not yet loaded, start loading.
-  if (!loaded_ && !IsRefreshing())
-    Load(callback);
-}
-
-void ChangeListLoader::Load(const FileOperationCallback& callback) {
-  DCHECK(thread_checker_.CalledOnValidThread());
-  DCHECK(!callback.is_null());
-
-  // Check if this is the first time this ChangeListLoader do loading.
-  // Note: IsRefreshing() depends on pending_load_callback_ so check in advance.
-  const bool is_initial_load = (!loaded_ && !IsRefreshing());
-
-  // Register the callback function to be called when it is loaded.
-  pending_load_callback_.push_back(callback);
-
-  // If loading task is already running, do nothing.
-  if (pending_load_callback_.size() > 1)
-    return;
-
-  // Check the current status of local metadata, and start loading if needed.
-  int64* local_changestamp = new int64(0);
-  base::PostTaskAndReplyWithResult(
-      blocking_task_runner_.get(),
-      FROM_HERE,
-      base::Bind(&ResourceMetadata::GetLargestChangestamp,
-                 base::Unretained(resource_metadata_),
-                 local_changestamp),
-      base::Bind(&ChangeListLoader::LoadAfterGetLargestChangestamp,
-                 weak_ptr_factory_.GetWeakPtr(),
-                 is_initial_load,
-                 base::Owned(local_changestamp)));
-}
-
-void ChangeListLoader::LoadAfterGetLargestChangestamp(
-    bool is_initial_load,
-    const int64* local_changestamp,
-    FileError error) {
-  DCHECK(thread_checker_.CalledOnValidThread());
-
-  if (error != FILE_ERROR_OK) {
-    OnChangeListLoadComplete(error);
-    return;
-  }
-
-  if (is_initial_load && *local_changestamp > 0) {
-    // The local data is usable. Flush callbacks to tell loading was successful.
-    OnChangeListLoadComplete(FILE_ERROR_OK);
-
-    // Continues to load from server in background.
-    // Put dummy callbacks to indicate that fetching is still continuing.
-    pending_load_callback_.push_back(
-        base::Bind(&util::EmptyFileOperationCallback));
-  }
-
-  about_resource_loader_->GetAboutResource(
-      base::Bind(&ChangeListLoader::LoadAfterGetAboutResource,
-                 weak_ptr_factory_.GetWeakPtr(),
-                 *local_changestamp));
-}
-
-void ChangeListLoader::LoadAfterGetAboutResource(
-    int64 local_changestamp,
-    google_apis::DriveApiErrorCode status,
-    scoped_ptr<google_apis::AboutResource> about_resource) {
-  DCHECK(thread_checker_.CalledOnValidThread());
-
-  FileError error = GDataToFileError(status);
-  if (error != FILE_ERROR_OK) {
-    OnChangeListLoadComplete(error);
-    return;
-  }
-
-  DCHECK(about_resource);
-
-  int64 remote_changestamp = about_resource->largest_change_id();
-  int64 start_changestamp = local_changestamp > 0 ? local_changestamp + 1 : 0;
-  if (local_changestamp >= remote_changestamp) {
-    if (local_changestamp > remote_changestamp) {
-      LOG(WARNING) << "Local resource metadata is fresher than server, "
-                   << "local = " << local_changestamp
-                   << ", server = " << remote_changestamp;
-    }
-
-    // No changes detected, tell the client that the loading was successful.
-    OnChangeListLoadComplete(FILE_ERROR_OK);
-  } else {
-    // Start loading the change list.
-    LoadChangeListFromServer(start_changestamp);
-  }
-}
-
-void ChangeListLoader::OnChangeListLoadComplete(FileError error) {
-  DCHECK(thread_checker_.CalledOnValidThread());
-
-  if (!loaded_ && error == FILE_ERROR_OK) {
-    loaded_ = true;
-    FOR_EACH_OBSERVER(ChangeListLoaderObserver,
-                      observers_,
-                      OnInitialLoadComplete());
-  }
-
-  for (size_t i = 0; i < pending_load_callback_.size(); ++i) {
-    base::ThreadTaskRunnerHandle::Get()->PostTask(
-        FROM_HERE,
-        base::Bind(pending_load_callback_[i], error));
-  }
-  pending_load_callback_.clear();
-
-  // If there is pending update check, try to load the change from the server
-  // again, because there may exist an update during the completed loading.
-  if (!pending_update_check_callback_.is_null()) {
-    Load(base::ResetAndReturn(&pending_update_check_callback_));
-  }
-}
-
-void ChangeListLoader::OnAboutResourceUpdated(
-    google_apis::DriveApiErrorCode error,
-    scoped_ptr<google_apis::AboutResource> resource) {
-  DCHECK(thread_checker_.CalledOnValidThread());
-
-  if (drive::GDataToFileError(error) != drive::FILE_ERROR_OK) {
-    logger_->Log(logging::LOG_ERROR,
-                 "Failed to update the about resource: %s",
-                 google_apis::DriveApiErrorCodeToString(error).c_str());
-    return;
-  }
-  logger_->Log(logging::LOG_INFO,
-               "About resource updated to: %s",
-               base::Int64ToString(resource->largest_change_id()).c_str());
-}
-
-void ChangeListLoader::LoadChangeListFromServer(int64 start_changestamp) {
-  DCHECK(thread_checker_.CalledOnValidThread());
-  DCHECK(!change_feed_fetcher_);
-  DCHECK(about_resource_loader_->cached_about_resource());
-
-  bool is_delta_update = start_changestamp != 0;
-
-  // Set up feed fetcher.
-  if (is_delta_update) {
-    change_feed_fetcher_.reset(
-        new DeltaFeedFetcher(scheduler_, start_changestamp));
-  } else {
-    change_feed_fetcher_.reset(new FullFeedFetcher(scheduler_));
-  }
-
-  // Make a copy of cached_about_resource_ to remember at which changestamp we
-  // are fetching change list.
-  change_feed_fetcher_->Run(
-      base::Bind(&ChangeListLoader::LoadChangeListFromServerAfterLoadChangeList,
-                 weak_ptr_factory_.GetWeakPtr(),
-                 base::Passed(make_scoped_ptr(new google_apis::AboutResource(
-                     *about_resource_loader_->cached_about_resource()))),
-                 is_delta_update));
-}
-
-void ChangeListLoader::LoadChangeListFromServerAfterLoadChangeList(
-    scoped_ptr<google_apis::AboutResource> about_resource,
-    bool is_delta_update,
-    FileError error,
-    ScopedVector<ChangeList> change_lists) {
-  DCHECK(thread_checker_.CalledOnValidThread());
-  DCHECK(about_resource);
-
-  // Delete the fetcher first.
-  change_feed_fetcher_.reset();
-
-  if (error != FILE_ERROR_OK) {
-    OnChangeListLoadComplete(error);
-    return;
-  }
-
-  ChangeListProcessor* change_list_processor =
-      new ChangeListProcessor(resource_metadata_, in_shutdown_.get());
-  // Don't send directory content change notification while performing
-  // the initial content retrieval.
-  const bool should_notify_changed_directories = is_delta_update;
-
-  logger_->Log(logging::LOG_INFO,
-               "Apply change lists (is delta: %d)",
-               is_delta_update);
-  loader_controller_->ScheduleRun(base::Bind(
-      base::IgnoreResult(
-          &base::PostTaskAndReplyWithResult<FileError, FileError>),
-      blocking_task_runner_,
-      FROM_HERE,
-      base::Bind(&ChangeListProcessor::Apply,
-                 base::Unretained(change_list_processor),
-                 base::Passed(&about_resource),
-                 base::Passed(&change_lists),
-                 is_delta_update),
-      base::Bind(&ChangeListLoader::LoadChangeListFromServerAfterUpdate,
-                 weak_ptr_factory_.GetWeakPtr(),
-                 base::Owned(change_list_processor),
-                 should_notify_changed_directories,
-                 base::Time::Now())));
-}
-
-void ChangeListLoader::LoadChangeListFromServerAfterUpdate(
-    ChangeListProcessor* change_list_processor,
-    bool should_notify_changed_directories,
-    const base::Time& start_time,
-    FileError error) {
-  DCHECK(thread_checker_.CalledOnValidThread());
-
-  const base::TimeDelta elapsed = base::Time::Now() - start_time;
-  logger_->Log(logging::LOG_INFO,
-               "Change lists applied (elapsed time: %sms)",
-               base::Int64ToString(elapsed.InMilliseconds()).c_str());
-
-  if (should_notify_changed_directories) {
-    FOR_EACH_OBSERVER(ChangeListLoaderObserver,
-                      observers_,
-                      OnFileChanged(change_list_processor->changed_files()));
-  }
-
-  OnChangeListLoadComplete(error);
-
-  FOR_EACH_OBSERVER(ChangeListLoaderObserver,
-                    observers_,
-                    OnLoadFromServerComplete());
-}
-
-}  // namespace internal
-}  // namespace drive