Revert 288017 "Parse Drive API responses all at once in the bloc..."

trunk/src/google_apis/drive/base_requests.h

 // 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.
 //
 // This file provides base classes used to issue HTTP requests for Google
 // APIs.
 
 #ifndef GOOGLE_APIS_DRIVE_BASE_REQUESTS_H_
 #define GOOGLE_APIS_DRIVE_BASE_REQUESTS_H_
 
@@ skipping 11 matching lines @@
 #include "url/gurl.h"
 
 namespace base {
 class Value;
 }  // namespace base
 
 namespace google_apis {
 
 class RequestSender;
 
+// Callback used to pass parsed JSON from ParseJson(). If parsing error occurs,
+// then the passed argument is null.
+typedef base::Callback<void(scoped_ptr<base::Value> value)> ParseJsonCallback;
+
 // Callback used for DownloadFileRequest and ResumeUploadRequestBase.
 typedef base::Callback<void(int64 progress, int64 total)> ProgressCallback;
 
 // Callback used to get the content from DownloadFileRequest.
 typedef base::Callback<void(
     GDataErrorCode error,
     scoped_ptr<std::string> content)> GetContentCallback;
 
-// Parses JSON passed in |json|. Returns NULL on failure.
-scoped_ptr<base::Value> ParseJson(const std::string& json);
+// Parses JSON passed in |json| on |blocking_task_runner|. Runs |callback| on
+// the calling thread when finished with either success or failure.
+// The callback must not be null.
+void ParseJson(base::TaskRunner* blocking_task_runner,
+               const std::string& json,
+               const ParseJsonCallback& callback);
 
 //======================= AuthenticatedRequestInterface ======================
 
 // An interface class for implementing a request which requires OAuth2
 // authentication.
 class AuthenticatedRequestInterface {
  public:
   // Called when re-authentication is required. See Start() for details.
   typedef base::Callback<void(AuthenticatedRequestInterface* request)>
       ReAuthenticateCallback;
@@ skipping 182 matching lines @@
   // Overridden from UrlFetchRequestBase.
   virtual void ProcessURLFetchResults(const net::URLFetcher* source) OVERRIDE;
   virtual void RunCallbackOnPrematureFailure(GDataErrorCode code) OVERRIDE;
 
  private:
   const EntryActionCallback callback_;
 
   DISALLOW_COPY_AND_ASSIGN(EntryActionRequest);
 };
 
+//============================== GetDataRequest ==============================
+
+// Callback type for requests that returns JSON data.
+typedef base::Callback<void(GDataErrorCode error,
+                            scoped_ptr<base::Value> json_data)> GetDataCallback;
+
+// This class performs the request for fetching and converting the fetched
+// content into a base::Value.
+class GetDataRequest : public UrlFetchRequestBase {
+ public:
+  // |callback| is called when the request finishes either by success or by
+  // failure. On success, a JSON Value object is passed. It must not be null.
+  GetDataRequest(RequestSender* sender, const GetDataCallback& callback);
+  virtual ~GetDataRequest();
+
+ protected:
+  // UrlFetchRequestBase overrides.
+  virtual void ProcessURLFetchResults(const net::URLFetcher* source) OVERRIDE;
+  virtual void RunCallbackOnPrematureFailure(
+      GDataErrorCode fetch_error_code) OVERRIDE;
+
+ private:
+  // Parses JSON response.
+  void ParseResponse(GDataErrorCode fetch_error_code, const std::string& data);
+
+  // Called when ParseJsonOnBlockingPool() is completed.
+  void OnDataParsed(GDataErrorCode fetch_error_code,
+                    scoped_ptr<base::Value> value);
+
+  const GetDataCallback callback_;
+
+  // 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<GetDataRequest> weak_ptr_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(GetDataRequest);
+};
+
+
 //=========================== InitiateUploadRequestBase=======================
 
 // Callback type for DriveServiceInterface::InitiateUpload.
 typedef base::Callback<void(GDataErrorCode 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.
@@ skipping 229 matching lines @@
   const ProgressCallback progress_callback_;
   const GURL download_url_;
   const base::FilePath output_file_path_;
 
   DISALLOW_COPY_AND_ASSIGN(DownloadFileRequestBase);
 };
 
 }  // namespace google_apis
 
 #endif  // GOOGLE_APIS_DRIVE_BASE_REQUESTS_H_