Extract GetResolveFile into DownloadOperation.

chrome/browser/chromeos/drive/file_system/download_operation.h

+// Copyright 2013 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_DRIVE_FILE_SYSTEM_DOWNLOAD_OPERATION_H_
+#define CHROME_BROWSER_CHROMEOS_DRIVE_FILE_SYSTEM_DOWNLOAD_OPERATION_H_
+
+#include "base/basictypes.h"
+#include "base/memory/scoped_ptr.h"
+#include "chrome/browser/chromeos/drive/file_errors.h"
+#include "chrome/browser/chromeos/drive/file_system_interface.h"
+#include "chrome/browser/chromeos/drive/job_list.h"
+#include "chrome/browser/google_apis/drive_service_interface.h"
+#include "chrome/browser/google_apis/gdata_errorcode.h"
+
+namespace base {
+class FilePath;
+class SequencedTaskRunner;
+}  // namespace base
+
+namespace google_apis {
+class ResourceEntry;
+}  // namespace google_apis
+
+namespace drive {
+
+class JobScheduler;
+class ResourceEntry;
+
+namespace internal {
+class FileCache;
+class ResourceMetadtata;
+}  // namespace internal
+
+namespace file_system {
+
+class OperationObserver;
+
+class DownloadOperation {
+ public:
+  DownloadOperation(base::SequencedTaskRunner* blocking_task_runner,
+                    OperationObserver* observer,
+                    JobScheduler* scheduler,
+                    internal::ResourceMetadata* metadata,
+                    internal::FileCache* cache);
+  ~DownloadOperation();
+
+  // Ensures that the file content is locally downloaded.
+  // For hosted documents, this method may create a JSON file representing the
+  // file.
+  // For regular files, if the locally cached file is found, returns it.
+  // If not found, start to download the file from the server.
+  // When a JSON file is created, the cache file is found or downloading is
+  // being started, |initialized_callback| is called with |local_file|
+  // for JSON file or the cache file, or with |cancel_download_closure| for
+  // downloading.
+  // During the downloading |get_content_callback| will be called periodically
+  // with the downloaded content.
+  // Upon completion or an error is found, |completion_callback| will be
+  // called.
+  // |initialized_callback| and |get_content_callback| can be null if not
+  // needed.
+  // |completion_callback| must not be null.
+  void EnsureFileDownloaded(
+      const base::FilePath& file_path,
+      DriveClientContext context,
+      const GetFileContentInitializedCallback& initialized_callback,
+      const google_apis::GetContentCallback& get_content_callback,
+      const GetFileCallback& completion_callback);
+
+ private:
+  // Thin wrapper of Callbacks for EnsureFileDownloaded.
+  class DownloadCallback;
+
+  // Parameters for JobScheduler::DownloadFile.
+  struct DownloadParams;
+
+  // Part of EnsureFileDownloaded(). Called upon the completion of precondition
+  // check.
+  void EnsureFileDownloadedAfterCheckPreCondition(
+      const base::FilePath& file_path,
+      DriveClientContext context,
+      const DownloadCallback& callback,
+      scoped_ptr<ResourceEntry> entry,
+      base::FilePath* cache_file_path,
+      FileError error);
+
+  // Part of EnsureFileDownloaded(). Called upon the completion of fetching
+  // ResourceEntry from the server.
+  void EnsureFileDownloadedAfterGetResourceEntry(
+      DriveClientContext context,
+      const DownloadCallback& callback,
+      google_apis::GDataErrorCode gdata_error,
+      scoped_ptr<google_apis::ResourceEntry> resource_entry);
+
+  // Part of EnsureFileDownloaded(). Called when it is ready to start
+  // downloading the file.
+  void EnsureFileDownloadedAfterPrepareForDownloadFile(
+      DownloadParams* params,
+      const DownloadCallback& callback,
+      FileError error);
+
+  // Part of EnsureFileDownloaded(). Called after the actual downloading.
+  void EnsureFileDownloadedAfterDownloadFile(
+      const base::FilePath& drive_file_path,
+      scoped_ptr<ResourceEntry> entry,
+      const DownloadCallback& callback,
+      google_apis::GDataErrorCode gdata_error,
+      const base::FilePath& downloaded_file_path);
+
+  // Part of EnsureFileDownloaded(). Called after updating local state is
+  // completed.
+  void EnsureFileDownloadedAfterUpdateLocalState(
+      const base::FilePath& file_path,
+      const DownloadCallback& callback,
+      scoped_ptr<ResourceEntry> entry,
+      base::FilePath* cache_file_path,
+      FileError error);
+
+  // Cancels the job with |job_id| in the scheduler.
+  void CancelJob(JobID job_id);
+
+  scoped_refptr<base::SequencedTaskRunner> blocking_task_runner_;
+  OperationObserver* observer_;
+  JobScheduler* scheduler_;
+  internal::ResourceMetadata* metadata_;
+  internal::FileCache* cache_;
+
+  // Note: This should remain the last member so it'll be destroyed and
+  // invalidate its weak pointers before any other members are destroyed.
+  base::WeakPtrFactory<DownloadOperation> weak_ptr_factory_;
+  DISALLOW_COPY_AND_ASSIGN(DownloadOperation);
+};
+
+}  // namespace file_system
+}  // namespace drive
+
+#endif  // CHROME_BROWSER_CHROMEOS_DRIVE_FILE_SYSTEM_DOWNLOAD_OPERATION_H_