google_apis/drive/drive_base_requests.h - chromium/src - Git at Google

 // Copyright 2021 The Chromium Authors
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // This file provides base classes used to issue HTTP requests for Google
 // APIs.

 #ifndef GOOGLE_APIS_DRIVE_DRIVE_BASE_REQUESTS_H_
 #define GOOGLE_APIS_DRIVE_DRIVE_BASE_REQUESTS_H_

 #include <stdint.h>

 #include <memory>
 #include <string>
 #include <utility>
 #include <vector>

 #include "base/files/file_path.h"
 #include "base/functional/callback.h"
 #include "base/memory/weak_ptr.h"
 #include "base/task/sequenced_task_runner.h"
 #include "base/threading/thread_checker.h"
 #include "google_apis/common/api_error_codes.h"
 #include "google_apis/common/base_requests.h"
 #include "services/network/public/cpp/simple_url_loader.h"
 #include "services/network/public/cpp/simple_url_loader_stream_consumer.h"
 #include "services/network/public/mojom/url_response_head.mojom-forward.h"
 #include "url/gurl.h"

 namespace base {
 class Value;
 }  // namespace base

 namespace google_apis {

 class FileResource;
 class RequestSender;

 // Content type for multipart body.
 enum class MultipartType { kRelated, kMixed };

 // Pair of content type and data.
 struct ContentTypeAndData {
   std::string type;
   std::string data;
 };

 // Callback used for requests that the server returns FileResource data
 // formatted into JSON value.
 typedef base::OnceCallback<void(ApiErrorCode error,
                                 std::unique_ptr<FileResource> entry)>
     FileResourceCallback;

 // Generate multipart body. If |predetermined_boundary| is not empty, it uses
 // the string as boundary. Otherwise it generates random boundary that does not
 // conflict with |parts|. If |data_offset| is not nullptr, it stores the
 // index of first byte of each part in multipart body.
 void GenerateMultipartBody(MultipartType multipart_type,
                            const std::string& predetermined_boundary,
                            const std::vector<ContentTypeAndData>& parts,
                            ContentTypeAndData* output,
                            std::vector<uint64_t>* data_offset);

 //============================ DriveUrlFetchRequestBase =======================

 // Base class for Drive requests that are fetching URLs.
 class DriveUrlFetchRequestBase : public UrlFetchRequestBase {
  public:
   DriveUrlFetchRequestBase(const DriveUrlFetchRequestBase&) = delete;
   DriveUrlFetchRequestBase& operator=(const DriveUrlFetchRequestBase&) = delete;

  protected:
   DriveUrlFetchRequestBase(RequestSender* sender,
                            ProgressCallback upload_progress_callback,
                            ProgressCallback download_progress_callback);
   ~DriveUrlFetchRequestBase() override;

   ApiErrorCode MapReasonToError(ApiErrorCode code,
                                 const std::string& reason) override;

   bool IsSuccessfulErrorCode(ApiErrorCode error) override;
 };

 //============================ BatchableDelegate ============================

 // Delegate to be used by |SingleBatchableDelegateRequest| and
 // |BatchUploadRequest|.
 class BatchableDelegate {
  public:
   virtual ~BatchableDelegate() = default;

   // See UrlFetchRequestBase.
   virtual GURL GetURL() const = 0;
   virtual HttpRequestMethod GetRequestType() const = 0;
   virtual std::vector<std::string> GetExtraRequestHeaders() const = 0;
   virtual void Prepare(PrepareCallback callback) = 0;
   virtual bool GetContentData(std::string* upload_content_type,
                               std::string* upload_content) = 0;

   // Notifies result of the request. Usually, it parses the |code| and
   // |response_body|, then notifies the parsed value to client code of the
   // API.  |callback| must be called on completion. The instance must not
   // do anything after calling |callback| since the instance may be deleted in
   // |callback|.
   virtual void NotifyResult(ApiErrorCode code,
                             const std::string& response_body,
                             base::OnceClosure callback) = 0;

   // Notifies error. Unlike |NotifyResult|, it must report error
   // synchronously. The instance may be deleted just after calling
   // NotifyError.
   virtual void NotifyError(ApiErrorCode code) = 0;

   // Notifies progress.
   virtual void NotifyUploadProgress(int64_t current, int64_t total) = 0;
 };

 //============================ EntryActionRequest ============================

 // Callback type for requests that return only error status, like: Delete/Move.
 using EntryActionCallback = base::OnceCallback<void(ApiErrorCode error)>;

 // This class performs a simple action over a given entry (document/file).
 // It is meant to be used for requests that return no JSON blobs.
 class EntryActionRequest : public DriveUrlFetchRequestBase {
  public:
   // |callback| is called when the request is finished either by success or by
   // failure. It must not be null.
   EntryActionRequest(RequestSender* sender, EntryActionCallback callback);
   EntryActionRequest(const EntryActionRequest&) = delete;
   EntryActionRequest& operator=(const EntryActionRequest&) = delete;
   ~EntryActionRequest() override;

  protected:
   // Overridden from UrlFetchRequestBase.
   void ProcessURLFetchResults(
       const network::mojom::URLResponseHead* response_head,
       base::FilePath response_file,
       std::string response_body) override;
   void RunCallbackOnPrematureFailure(ApiErrorCode code) override;

  private:
   EntryActionCallback callback_;
 };

 //=========================== InitiateUploadRequestBase=======================

 // Callback type for DriveServiceInterface::InitiateUpload.
 typedef base::OnceCallback<void(ApiErrorCode error, const GURL& upload_url)>
     InitiateUploadCallback;

 // This class provides base implementation for performing the request for
 // initiating the upload of a file.
 // |callback| will be called with the obtained upload URL. The URL will be
 // used with requests for resuming the file uploading.
 //
 // Here's the flow of uploading:
 // 1) Get the upload URL with a class inheriting InitiateUploadRequestBase.
 // 2) Upload the first 1GB (see kUploadChunkSize in drive_uploader.cc)
 //    of the target file to the upload URL
 // 3) If there is more data to upload, go to 2).
 //
 class InitiateUploadRequestBase : public DriveUrlFetchRequestBase {
  public:
   InitiateUploadRequestBase(const InitiateUploadRequestBase&) = delete;
   InitiateUploadRequestBase& operator=(const InitiateUploadRequestBase&) =
       delete;

  protected:
   // |callback| will be called with the upload URL, where upload data is
   // uploaded to with ResumeUploadRequestBase. It must not be null.
   // |content_type| and |content_length| should be the attributes of the
   // uploading file.
   InitiateUploadRequestBase(RequestSender* sender,
                             InitiateUploadCallback callback,
                             const std::string& content_type,
                             int64_t content_length);
   ~InitiateUploadRequestBase() override;

   // UrlFetchRequestBase overrides.
   void ProcessURLFetchResults(
       const network::mojom::URLResponseHead* response_head,
       base::FilePath response_file,
       std::string response_body) override;
   void RunCallbackOnPrematureFailure(ApiErrorCode code) override;
   std::vector<std::string> GetExtraRequestHeaders() const override;

  private:
   InitiateUploadCallback callback_;
   const std::string content_type_;
   const int64_t content_length_;
 };

 //========================== UploadRangeRequestBase ==========================

 // Struct for response to ResumeUpload and GetUploadStatus.
 struct UploadRangeResponse {
   UploadRangeResponse();
   UploadRangeResponse(ApiErrorCode code,
                       int64_t start_position_received,
                       int64_t end_position_received);
   ~UploadRangeResponse();

   ApiErrorCode code = HTTP_SUCCESS;
   // The values of "Range" header returned from the server. The values are
   // used to continue uploading more data. These are set to -1 if an upload
   // is complete.
   // |start_position_received| is inclusive and |end_position_received| is
   // exclusive to follow the common C++ manner, although the response from
   // the server has "Range" header in inclusive format at both sides.
   int64_t start_position_received = 0;
   int64_t end_position_received = 0;
 };

 // Base class for a URL fetch request expecting the response containing the
 // current uploading range. This class processes the response containing
 // "Range" header and invoke OnRangeRequestComplete.
 class UploadRangeRequestBase : public DriveUrlFetchRequestBase {
  public:
   UploadRangeRequestBase(const UploadRangeRequestBase&) = delete;
   UploadRangeRequestBase& operator=(const UploadRangeRequestBase&) = delete;

  protected:
   // |upload_url| is the URL of where to upload the file to.
   UploadRangeRequestBase(RequestSender* sender,
                          const GURL& upload_url,
                          ProgressCallback upload_progress_callback);
   ~UploadRangeRequestBase() override;

   // UrlFetchRequestBase overrides.
   GURL GetURL() const override;
   HttpRequestMethod GetRequestType() const override;
   void ProcessURLFetchResults(
       const network::mojom::URLResponseHead* response_head,
       base::FilePath response_file,
       std::string response_body) override;
   void RunCallbackOnPrematureFailure(ApiErrorCode code) override;

   // This method will be called when the request is done, regardless of
   // whether it is succeeded or failed.
   //
   // 1) If there is more data to upload, |code| of |response| is set to
   // HTTP_RESUME_INCOMPLETE, and positions are set appropriately. Also, |value|
   // will be set to NULL.
   // 2) If the upload is complete, |code| is set to HTTP_CREATED for a new file
   // or HTTP_SUCCESS for an existing file. Positions are set to -1, and |value|
   // is set to a parsed JSON value representing the uploaded file.
   // 3) If a premature failure is found, |code| is set to a value representing
   // the situation. Positions are set to 0, and |value| is set to NULL.
   //
   // See also the comments for UploadRangeResponse.
   // Note: Subclasses should have responsibility to run some callback
   // in this method to notify the finish status to its clients (or ignore it
   // under its responsibility).
   virtual void OnRangeRequestComplete(const UploadRangeResponse& response,
                                       std::unique_ptr<base::Value> value) = 0;

  private:
   // Called when ParseJson() is completed.
   void OnDataParsed(ApiErrorCode code, std::unique_ptr<base::Value> value);

   const GURL upload_url_;

   // 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<UploadRangeRequestBase> weak_ptr_factory_{this};
 };

 //========================== ResumeUploadRequestBase =========================

 // This class performs the request for resuming the upload of a file.
 // More specifically, this request uploads a chunk of data carried in |buf|
 // of ResumeUploadResponseBase. This class is designed to share the
 // implementation of upload resuming between GData WAPI and Drive API v2.
 // The subclasses should implement OnRangeRequestComplete inherited by
 // UploadRangeRequestBase, because the type of the response should be
 // different (although the format in the server response is JSON).
 class ResumeUploadRequestBase : public UploadRangeRequestBase {
  public:
   ResumeUploadRequestBase(const ResumeUploadRequestBase&) = delete;
   ResumeUploadRequestBase& operator=(const ResumeUploadRequestBase&) = delete;

  protected:
   // |start_position| is the start of range of contents currently stored in
   // |buf|. |end_position| is the end of range of contents currently stared in
   // |buf|. This is exclusive. For instance, if you are to upload the first
   // 500 bytes of data, |start_position| is 0 and |end_position| is 500.
   // |content_length| and |content_type| are the length and type of the
   // file content to be uploaded respectively.
   // |buf| holds current content to be uploaded.
   // See also UploadRangeRequestBase's comment for remaining parameters
   // meaning.
   ResumeUploadRequestBase(RequestSender* sender,
                           const GURL& upload_location,
                           int64_t start_position,
                           int64_t end_position,
                           int64_t content_length,
                           const std::string& content_type,
                           const base::FilePath& local_file_path,
                           ProgressCallback progress_callback);
   ~ResumeUploadRequestBase() override;

   // UrlFetchRequestBase overrides.
   std::vector<std::string> GetExtraRequestHeaders() const override;
   bool GetContentFile(base::FilePath* local_file_path,
                       int64_t* range_offset,
                       int64_t* range_length,
                       std::string* upload_content_type) override;

  private:
   // The parameters for the request. See ResumeUploadParams for the details.
   const int64_t start_position_;
   const int64_t end_position_;
   const int64_t content_length_;
   const std::string content_type_;
   const base::FilePath local_file_path_;
 };

 //======================== GetUploadStatusRequestBase ========================

 // This class performs the request for getting the current upload status
 // of a file.
 // This request calls OnRangeRequestComplete() with:
 // - HTTP_RESUME_INCOMPLETE and the range of previously uploaded data,
 //   if a file has been partially uploaded. |value| is not used.
 // - HTTP_SUCCESS or HTTP_CREATED (up to the upload mode) and |value|
 //   for the uploaded data, if a file has been completely uploaded.
 // See also UploadRangeRequestBase.
 class GetUploadStatusRequestBase : public UploadRangeRequestBase {
  public:
   // |content_length| is the whole data size to be uploaded.
   // See also UploadRangeRequestBase's constructor comment for other
   // parameters.
   GetUploadStatusRequestBase(RequestSender* sender,
                              const GURL& upload_url,
                              int64_t content_length);
   GetUploadStatusRequestBase(const GetUploadStatusRequestBase&) = delete;
   GetUploadStatusRequestBase& operator=(const GetUploadStatusRequestBase&) =
       delete;
   ~GetUploadStatusRequestBase() override;

  protected:
   // UrlFetchRequestBase overrides.
   std::vector<std::string> GetExtraRequestHeaders() const override;

  private:
   const int64_t content_length_;
 };

 //=========================== MultipartUploadRequestBase=======================

 // This class provides base implementation for performing the request for
 // uploading a file by multipart body.
 class MultipartUploadRequestBase : public BatchableDelegate {
  public:
   MultipartUploadRequestBase(const MultipartUploadRequestBase&) = delete;
   MultipartUploadRequestBase& operator=(const MultipartUploadRequestBase&) =
       delete;

   // Set boundary. Only tests can use this method.
   void SetBoundaryForTesting(const std::string& boundary);

  protected:
   // |callback| will be called with the file resource.upload URL.
   // |content_type| and |content_length| should be the attributes of the
   // uploading file. Other parameters are optional and can be empty or null
   // depending on Upload URL provided by the subclasses.
   MultipartUploadRequestBase(base::SequencedTaskRunner* blocking_task_runner,
                              const std::string& metadata_json,
                              const std::string& content_type,
                              int64_t content_length,
                              const base::FilePath& local_file_path,
                              FileResourceCallback callback,
                              ProgressCallback progress_callback);
   ~MultipartUploadRequestBase() override;

   // BatchableDelegate.
   std::vector<std::string> GetExtraRequestHeaders() const override;
   void Prepare(PrepareCallback callback) override;
   bool GetContentData(std::string* upload_content_type,
                       std::string* upload_content) override;
   void NotifyResult(ApiErrorCode code,
                     const std::string& body,
                     base::OnceClosure callback) override;
   void NotifyError(ApiErrorCode code) override;
   void NotifyUploadProgress(int64_t current, int64_t total) override;
   // Parses the response value and invokes |callback_| with |FileResource|.
   void OnDataParsed(ApiErrorCode code,
                     base::OnceClosure callback,
                     std::unique_ptr<base::Value> value);

  private:
   // Continues to rest part of |Start| method after determining boundary string
   // of multipart/related.
   void OnPrepareUploadContent(PrepareCallback callback,
                               std::string* upload_content_type,
                               std::string* upload_content_data,
                               bool result);

   scoped_refptr<base::SequencedTaskRunner> blocking_task_runner_;
   const std::string metadata_json_;
   const std::string content_type_;
   const base::FilePath local_path_;
   FileResourceCallback callback_;
   const ProgressCallback progress_callback_;

   // Boundary of multipart body.
   std::string boundary_;

   // Upload content of multipart body.
   std::string upload_content_type_;
   std::string upload_content_data_;

   THREAD_CHECKER(thread_checker_);

   // 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<MultipartUploadRequestBase> weak_ptr_factory_{this};
 };

 //============================ DownloadFileRequest ===========================

 // Callback type for receiving the completion of DownloadFileRequest.
 typedef base::OnceCallback<void(ApiErrorCode error,
                                 const base::FilePath& temp_file)>
     DownloadActionCallback;

 // This is a base class for performing the request for downloading a file.
 class DownloadFileRequestBase : public DriveUrlFetchRequestBase {
  public:
   // download_action_callback:
   //   This callback is called when the download is complete. Must not be null.
   //
   // get_content_callback:
   //   This callback is called when some part of the content is
   //   read. Used to read the download content progressively. May be null.
   //
   // progress_callback:
   //   This callback is called for periodically reporting the number of bytes
   //   downloaded so far. May be null.
   //
   // download_url:
   //   Specifies the target file to download.
   //
   // output_file_path:
   //   Specifies the file path to save the downloaded file.
   //
   DownloadFileRequestBase(RequestSender* sender,
                           DownloadActionCallback download_action_callback,
                           const GetContentCallback& get_content_callback,
                           ProgressCallback progress_callback,
                           const GURL& download_url,
                           const base::FilePath& output_file_path);
   DownloadFileRequestBase(const DownloadFileRequestBase&) = delete;
   DownloadFileRequestBase& operator=(const DownloadFileRequestBase&) = delete;
   ~DownloadFileRequestBase() override;

  protected:
   // UrlFetchRequestBase overrides.
   GURL GetURL() const override;
   void GetOutputFilePath(base::FilePath* local_file_path,
                          GetContentCallback* get_content_callback) override;
   void ProcessURLFetchResults(
       const network::mojom::URLResponseHead* response_head,
       base::FilePath response_file,
       std::string response_body) override;
   void RunCallbackOnPrematureFailure(ApiErrorCode code) override;

  private:
   DownloadActionCallback download_action_callback_;
   const GetContentCallback get_content_callback_;
   const GURL download_url_;
   const base::FilePath output_file_path_;
 };

 }  // namespace google_apis

 #endif  // GOOGLE_APIS_DRIVE_DRIVE_BASE_REQUESTS_H_
	// Copyright 2021 The Chromium Authors
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.
	//
	// This file provides base classes used to issue HTTP requests for Google
	// APIs.

	#ifndef GOOGLE_APIS_DRIVE_DRIVE_BASE_REQUESTS_H_
	#define GOOGLE_APIS_DRIVE_DRIVE_BASE_REQUESTS_H_

	#include <stdint.h>

	#include <memory>
	#include <string>
	#include <utility>
	#include <vector>

	#include "base/files/file_path.h"
	#include "base/functional/callback.h"
	#include "base/memory/weak_ptr.h"
	#include "base/task/sequenced_task_runner.h"
	#include "base/threading/thread_checker.h"
	#include "google_apis/common/api_error_codes.h"
	#include "google_apis/common/base_requests.h"
	#include "services/network/public/cpp/simple_url_loader.h"
	#include "services/network/public/cpp/simple_url_loader_stream_consumer.h"
	#include "services/network/public/mojom/url_response_head.mojom-forward.h"
	#include "url/gurl.h"

	namespace base {
	class Value;
	} // namespace base

	namespace google_apis {

	class FileResource;
	class RequestSender;

	// Content type for multipart body.
	enum class MultipartType { kRelated, kMixed };

	// Pair of content type and data.
	struct ContentTypeAndData {
	std::string type;
	std::string data;
	};

	// Callback used for requests that the server returns FileResource data
	// formatted into JSON value.
	typedef base::OnceCallback<void(ApiErrorCode error,
	std::unique_ptr<FileResource> entry)>
	FileResourceCallback;

	// Generate multipart body. If \|predetermined_boundary\| is not empty, it uses
	// the string as boundary. Otherwise it generates random boundary that does not
	// conflict with \|parts\|. If \|data_offset\| is not nullptr, it stores the
	// index of first byte of each part in multipart body.
	void GenerateMultipartBody(MultipartType multipart_type,
	const std::string& predetermined_boundary,
	const std::vector<ContentTypeAndData>& parts,
	ContentTypeAndData* output,
	std::vector<uint64_t>* data_offset);

	//============================ DriveUrlFetchRequestBase =======================

	// Base class for Drive requests that are fetching URLs.
	class DriveUrlFetchRequestBase : public UrlFetchRequestBase {
	public:
	DriveUrlFetchRequestBase(const DriveUrlFetchRequestBase&) = delete;
	DriveUrlFetchRequestBase& operator=(const DriveUrlFetchRequestBase&) = delete;

	protected:
	DriveUrlFetchRequestBase(RequestSender* sender,
	ProgressCallback upload_progress_callback,
	ProgressCallback download_progress_callback);
	~DriveUrlFetchRequestBase() override;

	ApiErrorCode MapReasonToError(ApiErrorCode code,
	const std::string& reason) override;

	bool IsSuccessfulErrorCode(ApiErrorCode error) override;
	};

	//============================ BatchableDelegate ============================

	// Delegate to be used by \|SingleBatchableDelegateRequest\| and
	// \|BatchUploadRequest\|.
	class BatchableDelegate {
	public:
	virtual ~BatchableDelegate() = default;

	// See UrlFetchRequestBase.
	virtual GURL GetURL() const = 0;
	virtual HttpRequestMethod GetRequestType() const = 0;
	virtual std::vector<std::string> GetExtraRequestHeaders() const = 0;
	virtual void Prepare(PrepareCallback callback) = 0;
	virtual bool GetContentData(std::string* upload_content_type,
	std::string* upload_content) = 0;

	// Notifies result of the request. Usually, it parses the \|code\| and
	// \|response_body\|, then notifies the parsed value to client code of the
	// API. \|callback\| must be called on completion. The instance must not
	// do anything after calling \|callback\| since the instance may be deleted in
	// \|callback\|.
	virtual void NotifyResult(ApiErrorCode code,
	const std::string& response_body,
	base::OnceClosure callback) = 0;

	// Notifies error. Unlike \|NotifyResult\|, it must report error
	// synchronously. The instance may be deleted just after calling
	// NotifyError.
	virtual void NotifyError(ApiErrorCode code) = 0;

	// Notifies progress.
	virtual void NotifyUploadProgress(int64_t current, int64_t total) = 0;
	};

	//============================ EntryActionRequest ============================

	// Callback type for requests that return only error status, like: Delete/Move.
	using EntryActionCallback = base::OnceCallback<void(ApiErrorCode error)>;

	// This class performs a simple action over a given entry (document/file).
	// It is meant to be used for requests that return no JSON blobs.
	class EntryActionRequest : public DriveUrlFetchRequestBase {
	public:
	// \|callback\| is called when the request is finished either by success or by
	// failure. It must not be null.
	EntryActionRequest(RequestSender* sender, EntryActionCallback callback);
	EntryActionRequest(const EntryActionRequest&) = delete;
	EntryActionRequest& operator=(const EntryActionRequest&) = delete;
	~EntryActionRequest() override;

	protected:
	// Overridden from UrlFetchRequestBase.
	void ProcessURLFetchResults(
	const network::mojom::URLResponseHead* response_head,
	base::FilePath response_file,
	std::string response_body) override;
	void RunCallbackOnPrematureFailure(ApiErrorCode code) override;

	private:
	EntryActionCallback callback_;
	};

	//=========================== InitiateUploadRequestBase=======================

	// Callback type for DriveServiceInterface::InitiateUpload.
	typedef base::OnceCallback<void(ApiErrorCode error, const GURL& upload_url)>
	InitiateUploadCallback;

	// This class provides base implementation for performing the request for
	// initiating the upload of a file.
	// \|callback\| will be called with the obtained upload URL. The URL will be
	// used with requests for resuming the file uploading.
	//
	// Here's the flow of uploading:
	// 1) Get the upload URL with a class inheriting InitiateUploadRequestBase.
	// 2) Upload the first 1GB (see kUploadChunkSize in drive_uploader.cc)
	// of the target file to the upload URL
	// 3) If there is more data to upload, go to 2).
	//
	class InitiateUploadRequestBase : public DriveUrlFetchRequestBase {
	public:
	InitiateUploadRequestBase(const InitiateUploadRequestBase&) = delete;
	InitiateUploadRequestBase& operator=(const InitiateUploadRequestBase&) =
	delete;

	protected:
	// \|callback\| will be called with the upload URL, where upload data is
	// uploaded to with ResumeUploadRequestBase. It must not be null.
	// \|content_type\| and \|content_length\| should be the attributes of the
	// uploading file.
	InitiateUploadRequestBase(RequestSender* sender,
	InitiateUploadCallback callback,
	const std::string& content_type,
	int64_t content_length);
	~InitiateUploadRequestBase() override;

	// UrlFetchRequestBase overrides.
	void ProcessURLFetchResults(
	const network::mojom::URLResponseHead* response_head,
	base::FilePath response_file,
	std::string response_body) override;
	void RunCallbackOnPrematureFailure(ApiErrorCode code) override;
	std::vector<std::string> GetExtraRequestHeaders() const override;

	private:
	InitiateUploadCallback callback_;
	const std::string content_type_;
	const int64_t content_length_;
	};

	//========================== UploadRangeRequestBase ==========================

	// Struct for response to ResumeUpload and GetUploadStatus.
	struct UploadRangeResponse {
	UploadRangeResponse();
	UploadRangeResponse(ApiErrorCode code,
	int64_t start_position_received,
	int64_t end_position_received);
	~UploadRangeResponse();

	ApiErrorCode code = HTTP_SUCCESS;
	// The values of "Range" header returned from the server. The values are
	// used to continue uploading more data. These are set to -1 if an upload
	// is complete.
	// \|start_position_received\| is inclusive and \|end_position_received\| is
	// exclusive to follow the common C++ manner, although the response from
	// the server has "Range" header in inclusive format at both sides.
	int64_t start_position_received = 0;
	int64_t end_position_received = 0;
	};

	// Base class for a URL fetch request expecting the response containing the
	// current uploading range. This class processes the response containing
	// "Range" header and invoke OnRangeRequestComplete.
	class UploadRangeRequestBase : public DriveUrlFetchRequestBase {
	public:
	UploadRangeRequestBase(const UploadRangeRequestBase&) = delete;
	UploadRangeRequestBase& operator=(const UploadRangeRequestBase&) = delete;

	protected:
	// \|upload_url\| is the URL of where to upload the file to.
	UploadRangeRequestBase(RequestSender* sender,
	const GURL& upload_url,
	ProgressCallback upload_progress_callback);
	~UploadRangeRequestBase() override;

	// UrlFetchRequestBase overrides.
	GURL GetURL() const override;
	HttpRequestMethod GetRequestType() const override;
	void ProcessURLFetchResults(
	const network::mojom::URLResponseHead* response_head,
	base::FilePath response_file,
	std::string response_body) override;
	void RunCallbackOnPrematureFailure(ApiErrorCode code) override;

	// This method will be called when the request is done, regardless of
	// whether it is succeeded or failed.
	//
	// 1) If there is more data to upload, \|code\| of \|response\| is set to
	// HTTP_RESUME_INCOMPLETE, and positions are set appropriately. Also, \|value\|
	// will be set to NULL.
	// 2) If the upload is complete, \|code\| is set to HTTP_CREATED for a new file
	// or HTTP_SUCCESS for an existing file. Positions are set to -1, and \|value\|
	// is set to a parsed JSON value representing the uploaded file.
	// 3) If a premature failure is found, \|code\| is set to a value representing
	// the situation. Positions are set to 0, and \|value\| is set to NULL.
	//
	// See also the comments for UploadRangeResponse.
	// Note: Subclasses should have responsibility to run some callback
	// in this method to notify the finish status to its clients (or ignore it
	// under its responsibility).
	virtual void OnRangeRequestComplete(const UploadRangeResponse& response,
	std::unique_ptr<base::Value> value) = 0;

	private:
	// Called when ParseJson() is completed.
	void OnDataParsed(ApiErrorCode code, std::unique_ptr<base::Value> value);

	const GURL upload_url_;

	// 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<UploadRangeRequestBase> weak_ptr_factory_{this};
	};

	//========================== ResumeUploadRequestBase =========================

	// This class performs the request for resuming the upload of a file.
	// More specifically, this request uploads a chunk of data carried in \|buf\|
	// of ResumeUploadResponseBase. This class is designed to share the
	// implementation of upload resuming between GData WAPI and Drive API v2.
	// The subclasses should implement OnRangeRequestComplete inherited by
	// UploadRangeRequestBase, because the type of the response should be
	// different (although the format in the server response is JSON).
	class ResumeUploadRequestBase : public UploadRangeRequestBase {
	public:
	ResumeUploadRequestBase(const ResumeUploadRequestBase&) = delete;
	ResumeUploadRequestBase& operator=(const ResumeUploadRequestBase&) = delete;

	protected:
	// \|start_position\| is the start of range of contents currently stored in
	// \|buf\|. \|end_position\| is the end of range of contents currently stared in
	// \|buf\|. This is exclusive. For instance, if you are to upload the first
	// 500 bytes of data, \|start_position\| is 0 and \|end_position\| is 500.
	// \|content_length\| and \|content_type\| are the length and type of the
	// file content to be uploaded respectively.
	// \|buf\| holds current content to be uploaded.
	// See also UploadRangeRequestBase's comment for remaining parameters
	// meaning.
	ResumeUploadRequestBase(RequestSender* sender,
	const GURL& upload_location,
	int64_t start_position,
	int64_t end_position,
	int64_t content_length,
	const std::string& content_type,
	const base::FilePath& local_file_path,
	ProgressCallback progress_callback);
	~ResumeUploadRequestBase() override;

	// UrlFetchRequestBase overrides.
	std::vector<std::string> GetExtraRequestHeaders() const override;
	bool GetContentFile(base::FilePath* local_file_path,
	int64_t* range_offset,
	int64_t* range_length,
	std::string* upload_content_type) override;

	private:
	// The parameters for the request. See ResumeUploadParams for the details.
	const int64_t start_position_;
	const int64_t end_position_;
	const int64_t content_length_;
	const std::string content_type_;
	const base::FilePath local_file_path_;
	};

	//======================== GetUploadStatusRequestBase ========================

	// This class performs the request for getting the current upload status
	// of a file.
	// This request calls OnRangeRequestComplete() with:
	// - HTTP_RESUME_INCOMPLETE and the range of previously uploaded data,
	// if a file has been partially uploaded. \|value\| is not used.
	// - HTTP_SUCCESS or HTTP_CREATED (up to the upload mode) and \|value\|
	// for the uploaded data, if a file has been completely uploaded.
	// See also UploadRangeRequestBase.
	class GetUploadStatusRequestBase : public UploadRangeRequestBase {
	public:
	// \|content_length\| is the whole data size to be uploaded.
	// See also UploadRangeRequestBase's constructor comment for other
	// parameters.
	GetUploadStatusRequestBase(RequestSender* sender,
	const GURL& upload_url,
	int64_t content_length);
	GetUploadStatusRequestBase(const GetUploadStatusRequestBase&) = delete;
	GetUploadStatusRequestBase& operator=(const GetUploadStatusRequestBase&) =
	delete;
	~GetUploadStatusRequestBase() override;

	protected:
	// UrlFetchRequestBase overrides.
	std::vector<std::string> GetExtraRequestHeaders() const override;

	private:
	const int64_t content_length_;
	};

	//=========================== MultipartUploadRequestBase=======================

	// This class provides base implementation for performing the request for
	// uploading a file by multipart body.
	class MultipartUploadRequestBase : public BatchableDelegate {
	public:
	MultipartUploadRequestBase(const MultipartUploadRequestBase&) = delete;
	MultipartUploadRequestBase& operator=(const MultipartUploadRequestBase&) =
	delete;

	// Set boundary. Only tests can use this method.
	void SetBoundaryForTesting(const std::string& boundary);

	protected:
	// \|callback\| will be called with the file resource.upload URL.
	// \|content_type\| and \|content_length\| should be the attributes of the
	// uploading file. Other parameters are optional and can be empty or null
	// depending on Upload URL provided by the subclasses.
	MultipartUploadRequestBase(base::SequencedTaskRunner* blocking_task_runner,
	const std::string& metadata_json,
	const std::string& content_type,
	int64_t content_length,
	const base::FilePath& local_file_path,
	FileResourceCallback callback,
	ProgressCallback progress_callback);
	~MultipartUploadRequestBase() override;

	// BatchableDelegate.
	std::vector<std::string> GetExtraRequestHeaders() const override;
	void Prepare(PrepareCallback callback) override;
	bool GetContentData(std::string* upload_content_type,
	std::string* upload_content) override;
	void NotifyResult(ApiErrorCode code,
	const std::string& body,
	base::OnceClosure callback) override;
	void NotifyError(ApiErrorCode code) override;
	void NotifyUploadProgress(int64_t current, int64_t total) override;
	// Parses the response value and invokes \|callback_\| with \|FileResource\|.
	void OnDataParsed(ApiErrorCode code,
	base::OnceClosure callback,
	std::unique_ptr<base::Value> value);

	private:
	// Continues to rest part of \|Start\| method after determining boundary string
	// of multipart/related.
	void OnPrepareUploadContent(PrepareCallback callback,
	std::string* upload_content_type,
	std::string* upload_content_data,
	bool result);

	scoped_refptr<base::SequencedTaskRunner> blocking_task_runner_;
	const std::string metadata_json_;
	const std::string content_type_;
	const base::FilePath local_path_;
	FileResourceCallback callback_;
	const ProgressCallback progress_callback_;

	// Boundary of multipart body.
	std::string boundary_;

	// Upload content of multipart body.
	std::string upload_content_type_;
	std::string upload_content_data_;

	THREAD_CHECKER(thread_checker_);

	// 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<MultipartUploadRequestBase> weak_ptr_factory_{this};
	};

	//============================ DownloadFileRequest ===========================

	// Callback type for receiving the completion of DownloadFileRequest.
	typedef base::OnceCallback<void(ApiErrorCode error,
	const base::FilePath& temp_file)>
	DownloadActionCallback;

	// This is a base class for performing the request for downloading a file.
	class DownloadFileRequestBase : public DriveUrlFetchRequestBase {
	public:
	// download_action_callback:
	// This callback is called when the download is complete. Must not be null.
	//
	// get_content_callback:
	// This callback is called when some part of the content is
	// read. Used to read the download content progressively. May be null.
	//
	// progress_callback:
	// This callback is called for periodically reporting the number of bytes
	// downloaded so far. May be null.
	//
	// download_url:
	// Specifies the target file to download.
	//
	// output_file_path:
	// Specifies the file path to save the downloaded file.
	//
	DownloadFileRequestBase(RequestSender* sender,
	DownloadActionCallback download_action_callback,
	const GetContentCallback& get_content_callback,
	ProgressCallback progress_callback,
	const GURL& download_url,
	const base::FilePath& output_file_path);
	DownloadFileRequestBase(const DownloadFileRequestBase&) = delete;
	DownloadFileRequestBase& operator=(const DownloadFileRequestBase&) = delete;
	~DownloadFileRequestBase() override;

	protected:
	// UrlFetchRequestBase overrides.
	GURL GetURL() const override;
	void GetOutputFilePath(base::FilePath* local_file_path,
	GetContentCallback* get_content_callback) override;
	void ProcessURLFetchResults(
	const network::mojom::URLResponseHead* response_head,
	base::FilePath response_file,
	std::string response_body) override;
	void RunCallbackOnPrematureFailure(ApiErrorCode code) override;

	private:
	DownloadActionCallback download_action_callback_;
	const GetContentCallback get_content_callback_;
	const GURL download_url_;
	const base::FilePath output_file_path_;
	};

	} // namespace google_apis

	#endif // GOOGLE_APIS_DRIVE_DRIVE_BASE_REQUESTS_H_