CLOUD: Refactor Request

Added ErrorResponse and ErrorCallback. Each Request now has an
ErrorCallback, which should be called instead of usual callback in case
of failure.

backends/cloud/downloadrequest.cpp

@@ -27,31 +27,55 @@
 
 namespace Cloud {
 
-DownloadRequest::DownloadRequest(Storage *storage, Storage::BoolCallback callback, Common::String remoteFile, Common::DumpFile *dumpFile):
+DownloadRequest::DownloadRequest(Storage *storage, Storage::BoolCallback callback, Networking::ErrorCallback ecb, Common::String remoteFile, Common::DumpFile *dumpFile):
-	Request(0), _boolCallback(callback), _remoteFileStream(0), _localFile(dumpFile) {
+	Request(nullptr, ecb), _boolCallback(callback), _localFile(dumpFile), _remoteFileName(remoteFile), _storage(storage),
-	storage->streamFile(remoteFile, new Common::Callback<DownloadRequest, Networking::NetworkReadStreamResponse>(this, &DownloadRequest::streamCallback));
+	_remoteFileStream(nullptr), _workingRequest(nullptr), _ignoreCallback(false) {
+	start();
 }
 
-void DownloadRequest::streamCallback(Networking::NetworkReadStreamResponse pair) {
+DownloadRequest::~DownloadRequest() {
-	if (!pair.value) {
+	_ignoreCallback = true;
-		warning("DownloadRequest: no ReadStream passed");
+	if (_workingRequest) _workingRequest->finish();
-		finish();
+	delete _boolCallback;
-		return;
+	delete _localFile;
-	}
+}
 
-	_remoteFileStream = (Networking::NetworkReadStream *)pair.value;
+void DownloadRequest::start() {
+	_ignoreCallback = true;
+	if (_workingRequest) _workingRequest->finish();
+	_remoteFileStream = nullptr;
+	//TODO: reopen DumpFile
+	_ignoreCallback = false;
+
+	_workingRequest = _storage->streamFile(
+		_remoteFileName,
+		new Common::Callback<DownloadRequest, Networking::NetworkReadStreamResponse>(this, &DownloadRequest::streamCallback),
+		new Common::Callback<DownloadRequest, Networking::ErrorResponse>(this, &DownloadRequest::streamErrorCallback)
+	);
+}
+
+void DownloadRequest::streamCallback(Networking::NetworkReadStreamResponse response) {
+	_workingRequest = nullptr;
+	if (_ignoreCallback) return;
+	_remoteFileStream = (Networking::NetworkReadStream *)response.value;
+}
+
+void DownloadRequest::streamErrorCallback(Networking::ErrorResponse error) {
+	_workingRequest = nullptr;
+	if (_ignoreCallback) return;
+	finishError(error);
 }
 
 void DownloadRequest::handle() {	
 	if (!_localFile) {
 		warning("DownloadRequest: no file to write");
-		finish();
+		finishError(Networking::ErrorResponse(this, false, true, "", -1));
 		return;
 	}
 
 	if (!_localFile->isOpen()) {
 		warning("DownloadRequest: failed to open file to write");
-		finish();
+		finishError(Networking::ErrorResponse(this, false, true, "", -1));
 		return;
 	}
 
@@ -67,7 +91,7 @@ void DownloadRequest::handle() {
 	if (readBytes != 0)
 		if (_localFile->write(buf, readBytes) != readBytes) {
 			warning("DownloadRequest: unable to write all received bytes into output file");
-			finish();
+			finishError(Networking::ErrorResponse(this, false, true, "", -1));
 			return;
 		}
 
@@ -77,26 +101,20 @@ void DownloadRequest::handle() {
 			//TODO: do something about it actually			
 		}
 
-		finishBool(_remoteFileStream->httpResponseCode() == 200);
+		finishSuccess(_remoteFileStream->httpResponseCode() == 200);
 
 		_localFile->close(); //yes, I know it's closed automatically in ~DumpFile()		
 	}
 }
 
 void DownloadRequest::restart() {
-	//this request doesn't know anything about the _remoteFileStream it's reading
+	warning("DownloadRequest: can't restart as there are no means to reopen DumpFile");
-	//thus, it can't restart it
+	finishError(Networking::ErrorResponse(this, false, true, "", -1));
-	warning("DownloadRequest: cannot be restarted");
+	//start();
-	finish();
-	//TODO: fix that
 }
 
-void DownloadRequest::finish() {
+void DownloadRequest::finishSuccess(bool success) {
-	finishBool(false);
+	Request::finishSuccess();
-}
-
-void DownloadRequest::finishBool(bool success) {
-	Request::finish();
 	if (_boolCallback) (*_boolCallback)(Storage::BoolResponse(this, success));
 }
 

backends/cloud/downloadrequest.h

@@ -32,22 +32,23 @@ namespace Cloud {
 
 class DownloadRequest: public Networking::Request {	
 	Storage::BoolCallback _boolCallback;	
-	Networking::NetworkReadStream *_remoteFileStream;
 	Common::DumpFile *_localFile;
+	Common::String _remoteFileName;
+	Storage *_storage;
+	Networking::NetworkReadStream *_remoteFileStream;
+	Request *_workingRequest;
+	bool _ignoreCallback;
 
-	void streamCallback(Networking::NetworkReadStreamResponse pair);
+	void start();
-
+	void streamCallback(Networking::NetworkReadStreamResponse response);
-	void finishBool(bool success);
+	void streamErrorCallback(Networking::ErrorResponse error);
+	void finishSuccess(bool success);
 public:
-	DownloadRequest(Storage *storage, Storage::BoolCallback callback, Common::String remoteFile, Common::DumpFile *dumpFile);
+	DownloadRequest(Storage *storage, Storage::BoolCallback callback, Networking::ErrorCallback ecb, Common::String remoteFile, Common::DumpFile *dumpFile);
-	virtual ~DownloadRequest() {
+	virtual ~DownloadRequest();
-		delete _boolCallback;
-		delete _localFile;
-	}
 
 	virtual void handle();
 	virtual void restart();
-	virtual void finish();
 };
 
 } // End of namespace Cloud

backends/cloud/dropbox/dropboxlistdirectoryrequest.cpp

@@ -31,8 +31,8 @@
 namespace Cloud {
 namespace Dropbox {
 
-DropboxListDirectoryRequest::DropboxListDirectoryRequest(Common::String token, Common::String path, Storage::ListDirectoryCallback cb, bool recursive):
+DropboxListDirectoryRequest::DropboxListDirectoryRequest(Common::String token, Common::String path, Storage::ListDirectoryCallback cb, Networking::ErrorCallback ecb, bool recursive):
-	Networking::Request(0), _requestedPath(path), _requestedRecursive(recursive), _listDirectoryCallback(cb),
+	Networking::Request(nullptr, ecb), _requestedPath(path), _requestedRecursive(recursive), _listDirectoryCallback(cb),
 	_token(token), _workingRequest(nullptr), _ignoreCallback(false) {
 	start();
 }
@@ -49,8 +49,9 @@ void DropboxListDirectoryRequest::start() {
 	_files.clear();
 	_ignoreCallback = false;
 
-	Networking::JsonCallback innerCallback = new Common::Callback<DropboxListDirectoryRequest, Networking::JsonResponse>(this, &DropboxListDirectoryRequest::responseCallback);
+	Networking::JsonCallback callback = new Common::Callback<DropboxListDirectoryRequest, Networking::JsonResponse>(this, &DropboxListDirectoryRequest::responseCallback);
-	Networking::CurlJsonRequest *request = new Networking::CurlJsonRequest(innerCallback, "https://api.dropboxapi.com/2/files/list_folder");
+	Networking::ErrorCallback failureCallback = new Common::Callback<DropboxListDirectoryRequest, Networking::ErrorResponse>(this, &DropboxListDirectoryRequest::errorCallback);
+	Networking::CurlJsonRequest *request = new Networking::CurlJsonRequest(callback, failureCallback, "https://api.dropboxapi.com/2/files/list_folder");
 	request->addHeader("Authorization: Bearer " + _token);
 	request->addHeader("Content-Type: application/json");
 
@@ -66,33 +67,32 @@ void DropboxListDirectoryRequest::start() {
 	_workingRequest = ConnMan.addRequest(request);
 }
 
-
+void DropboxListDirectoryRequest::responseCallback(Networking::JsonResponse response) {
-void DropboxListDirectoryRequest::responseCallback(Networking::JsonResponse pair) {
 	_workingRequest = nullptr;
 	if (_ignoreCallback) return;
 
-	ListDirectoryStatus status(_files);
+	Networking::ErrorResponse error(this);
-	Networking::CurlJsonRequest *rq = (Networking::CurlJsonRequest *)pair.request;
+	Networking::CurlJsonRequest *rq = (Networking::CurlJsonRequest *)response.request;
 	if (rq && rq->getNetworkReadStream())
-		status.httpResponseCode = rq->getNetworkReadStream()->httpResponseCode();
+		error.httpResponseCode = rq->getNetworkReadStream()->httpResponseCode();
 
-	Common::JSONValue *json = pair.value;
+	Common::JSONValue *json = response.value;
 	if (json) {
-		Common::JSONObject response = json->asObject();
+		Common::JSONObject responseObjecct = json->asObject();
 		
-		if (response.contains("error") || response.contains("error_summary")) {
+		if (responseObjecct.contains("error") || responseObjecct.contains("error_summary")) {
-			warning("Dropbox returned error: %s", response.getVal("error_summary")->asString().c_str());
+			warning("Dropbox returned error: %s", responseObjecct.getVal("error_summary")->asString().c_str());
-			status.failed = true;
+			error.failed = true;
-			status.response = json->stringify();
+			error.response = json->stringify();
-			finishStatus(status);
+			finishError(error);
 			delete json;
 			return;
 		}
 
 		//TODO: check that ALL keys exist AND HAVE RIGHT TYPE to avoid segfaults		
 
-		if (response.contains("entries")) {
+		if (responseObjecct.contains("entries")) {
-			Common::JSONArray items = response.getVal("entries")->asArray();
+			Common::JSONArray items = responseObjecct.getVal("entries")->asArray();
 			for (uint32 i = 0; i < items.size(); ++i) {
 				Common::JSONObject item = items[i]->asObject();
 				Common::String path = item.getVal("path_lower")->asString();
@@ -106,47 +106,47 @@ void DropboxListDirectoryRequest::responseCallback(Networking::JsonResponse pair
 			}
 		}
 
-		bool hasMore = (response.contains("has_more") && response.getVal("has_more")->asBool());
+		bool hasMore = (responseObjecct.contains("has_more") && responseObjecct.getVal("has_more")->asBool());
 
 		if (hasMore) {			
-			Networking::JsonCallback innerCallback = new Common::Callback<DropboxListDirectoryRequest, Networking::JsonResponse>(this, &DropboxListDirectoryRequest::responseCallback);
+			Networking::JsonCallback callback = new Common::Callback<DropboxListDirectoryRequest, Networking::JsonResponse>(this, &DropboxListDirectoryRequest::responseCallback);
-			Networking::CurlJsonRequest *request = new Networking::CurlJsonRequest(innerCallback, "https://api.dropboxapi.com/2/files/list_folder/continue");
+			Networking::ErrorCallback failureCallback = new Common::Callback<DropboxListDirectoryRequest, Networking::ErrorResponse>(this, &DropboxListDirectoryRequest::errorCallback);
+			Networking::CurlJsonRequest *request = new Networking::CurlJsonRequest(callback, failureCallback, "https://api.dropboxapi.com/2/files/list_folder/continue");
 			request->addHeader("Authorization: Bearer " + _token);
 			request->addHeader("Content-Type: application/json");
 
 			Common::JSONObject jsonRequestParameters;
-			jsonRequestParameters.setVal("cursor", new Common::JSONValue(response.getVal("cursor")->asString()));
+			jsonRequestParameters.setVal("cursor", new Common::JSONValue(responseObjecct.getVal("cursor")->asString()));
 
 			Common::JSONValue value(jsonRequestParameters);
 			request->addPostField(Common::JSON::stringify(&value));
 
 			_workingRequest = ConnMan.addRequest(request);
 		} else {			
-			finishStatus(status);
+			finishSuccess(_files);
 		}		
 	} else {
 		warning("null, not json");
-		status.failed = true;
+		error.failed = true;
-		finishStatus(status);
+		finishError(error);
 	}
 
 	delete json;
 }
 
+void DropboxListDirectoryRequest::errorCallback(Networking::ErrorResponse error) {
+	_workingRequest = nullptr;
+	if (_ignoreCallback) return;
+	finishError(error);
+}
+
 void DropboxListDirectoryRequest::handle() {}
 
 void DropboxListDirectoryRequest::restart() { start(); }
 
-void DropboxListDirectoryRequest::finish() {
+void DropboxListDirectoryRequest::finishSuccess(Common::Array<StorageFile> &files) {	
-	Common::Array<StorageFile> files;
+	Request::finishSuccess();
-	ListDirectoryStatus status(files);
+	if (_listDirectoryCallback) (*_listDirectoryCallback)(Storage::ListDirectoryResponse(this, files));
-	status.interrupted = true;
-	finishStatus(status);
-}
-
-void DropboxListDirectoryRequest::finishStatus(ListDirectoryStatus status) {
-	Request::finish();
-	if (_listDirectoryCallback) (*_listDirectoryCallback)(Storage::ListDirectoryResponse(this, status));
 }
 
 } // End of namespace Dropbox

backends/cloud/dropbox/dropboxlistdirectoryrequest.h

@@ -42,15 +42,15 @@ class DropboxListDirectoryRequest: public Networking::Request {
 	bool _ignoreCallback;
 	
 	void start();
-	void responseCallback(Networking::JsonResponse pair);
+	void responseCallback(Networking::JsonResponse response);
-	void finishStatus(ListDirectoryStatus status);
+	void errorCallback(Networking::ErrorResponse error);
+	void finishSuccess(Common::Array<StorageFile> &files);
 public:
-	DropboxListDirectoryRequest(Common::String token, Common::String path, Storage::ListDirectoryCallback cb, bool recursive = false);
+	DropboxListDirectoryRequest(Common::String token, Common::String path, Storage::ListDirectoryCallback cb, Networking::ErrorCallback ecb, bool recursive = false);
 	virtual ~DropboxListDirectoryRequest();
 
 	virtual void handle();
 	virtual void restart();
-	virtual void finish();
 };
 
 } // End of namespace Dropbox

backends/cloud/dropbox/dropboxstorage.cpp

@@ -96,118 +96,93 @@ void DropboxStorage::saveConfig(Common::String keyPrefix) {
 	ConfMan.set(keyPrefix + "user_id", _uid, "cloud");
 }
 
-void DropboxStorage::printFiles(FileArrayResponse pair) {
+void DropboxStorage::printFiles(FileArrayResponse response) {
 	debug("files:");
-	Common::Array<StorageFile> &files = pair.value;
+	Common::Array<StorageFile> &files = response.value;
 	for (uint32 i = 0; i < files.size(); ++i)
 		debug("\t%s", files[i].name().c_str());
 }
 
-void DropboxStorage::printBool(BoolResponse pair) {
+void DropboxStorage::printBool(BoolResponse response) {
-	debug("bool: %s", (pair.value?"true":"false"));
+	debug("bool: %s", (response.value?"true":"false"));
 }
 
-void DropboxStorage::printUploadStatus(UploadResponse pair) {
+void DropboxStorage::printStorageFile(UploadResponse response) {	
-	debug(" ");
+	debug("\nuploaded file info:");
-	UploadStatus status = pair.value;
+	debug("\tpath: %s", response.value.path().c_str());
-	if (status.interrupted) {
+	debug("\tsize: %u", response.value.size());
-		debug("upload interrupted by user");
+	debug("\ttimestamp: %u", response.value.timestamp());
-		return;
-	}
-	if (status.failed) {
-		debug("upload failed with following response:");
-		debug("%s", status.response.c_str());
-		return;
-	}
-	debug("upload HTTP response code = %ld", status.httpResponseCode);
-	if (!status.failed) {
-		debug("uploaded file info:");
-		debug("\tpath: %s", status.file.path().c_str());
-		debug("\tsize: %u", status.file.size());
-		debug("\ttimestamp: %u", status.file.timestamp());
-	}
 }
 
-Networking::Request *DropboxStorage::listDirectory(Common::String path, ListDirectoryCallback outerCallback, bool recursive) {
+void DropboxStorage::printErrorResponse(Networking::ErrorResponse error) {
-	return ConnMan.addRequest(new DropboxListDirectoryRequest(_token, path, outerCallback, recursive));
+	debug("error response (%s, %ld):", (error.failed ? "failed" : "interrupted"), error.httpResponseCode);
+	debug("%s", error.response.c_str());
 }
 
-Networking::Request *DropboxStorage::upload(Common::String path, Common::SeekableReadStream *contents, UploadCallback callback) {
+Networking::ErrorCallback DropboxStorage::getErrorPrintingCallback() {
-	return ConnMan.addRequest(new DropboxUploadRequest(_token, path, contents, callback));
+	return new Common::Callback<DropboxStorage, Networking::ErrorResponse>(this, &DropboxStorage::printErrorResponse);
 }
 
-Networking::Request *DropboxStorage::upload(Common::String remotePath, Common::String localPath, UploadCallback callback) {
+Networking::Request *DropboxStorage::listDirectory(Common::String path, ListDirectoryCallback outerCallback, Networking::ErrorCallback errorCallback, bool recursive) {
+	return ConnMan.addRequest(new DropboxListDirectoryRequest(_token, path, outerCallback, errorCallback, recursive));
+}
+
+Networking::Request *DropboxStorage::upload(Common::String path, Common::SeekableReadStream *contents, UploadCallback callback, Networking::ErrorCallback errorCallback) {
+	return ConnMan.addRequest(new DropboxUploadRequest(_token, path, contents, callback, errorCallback));
+}
+
+Networking::Request *DropboxStorage::upload(Common::String remotePath, Common::String localPath, UploadCallback callback, Networking::ErrorCallback errorCallback) {
 	Common::File *f = new Common::File();
 	if (!f->open(localPath)) {
 		warning("DropboxStorage: unable to open file to upload from");
-		UploadStatus status(false, true, StorageFile(), "", -1);
+		if (errorCallback) (*errorCallback)(Networking::ErrorResponse(nullptr, false, true, "", -1));
-		if (callback) (*callback)(UploadResponse(nullptr, status));
+		delete errorCallback;
+		delete callback;
 		delete f;
 		return nullptr;
 	}
-	return upload(remotePath, f, callback);
+	return upload(remotePath, f, callback, errorCallback);
 }
 
-Networking::Request *DropboxStorage::streamFile(Common::String path, Networking::NetworkReadStreamCallback callback) {
+Networking::Request *DropboxStorage::streamFile(Common::String path, Networking::NetworkReadStreamCallback callback, Networking::ErrorCallback errorCallback) {
 	Common::JSONObject jsonRequestParameters;
 	jsonRequestParameters.setVal("path", new Common::JSONValue(path));
 	Common::JSONValue value(jsonRequestParameters);
 
-	Networking::CurlRequest *request = new Networking::CurlRequest(0, "https://content.dropboxapi.com/2/files/download");
+	Networking::CurlRequest *request = new Networking::CurlRequest(nullptr, nullptr, "https://content.dropboxapi.com/2/files/download"); //TODO: is it right?
 	request->addHeader("Authorization: Bearer " + _token);
 	request->addHeader("Dropbox-API-Arg: " + Common::JSON::stringify(&value));
 	request->addHeader("Content-Type: "); //required to be empty (as we do POST, it's usually app/form-url-encoded)
 
-	Networking::NetworkReadStreamResponse pair = request->execute();
+	Networking::NetworkReadStreamResponse response = request->execute();
-	if (callback) (*callback)(pair);
+	if (callback) (*callback)(response);
-	return pair.request;
+	return response.request;
 }
 
-Networking::Request *DropboxStorage::download(Common::String remotePath, Common::String localPath, BoolCallback callback) {
+Networking::Request *DropboxStorage::download(Common::String remotePath, Common::String localPath, BoolCallback callback, Networking::ErrorCallback errorCallback) {
 	Common::DumpFile *f = new Common::DumpFile();
 	if (!f->open(localPath, true)) {
 		warning("DropboxStorage: unable to open file to download into");
-		if (callback) (*callback)(BoolResponse(nullptr, false));
+		if (errorCallback) (*errorCallback)(Networking::ErrorResponse(nullptr, false, true, "", -1));
 		delete f;
 		return nullptr;
 	}
 
-	return ConnMan.addRequest(new DownloadRequest(this, callback, remotePath, f));
+	return ConnMan.addRequest(new DownloadRequest(this, callback, errorCallback, remotePath, f));
 }
 
-Networking::Request *DropboxStorage::downloadFolder(Common::String remotePath, Common::String localPath, FileArrayCallback callback, bool recursive) {
+Networking::Request *DropboxStorage::downloadFolder(Common::String remotePath, Common::String localPath, FileArrayCallback callback, Networking::ErrorCallback errorCallback, bool recursive) {
-	return ConnMan.addRequest(new FolderDownloadRequest(this, callback, remotePath, localPath, recursive));
+	return ConnMan.addRequest(new FolderDownloadRequest(this, callback, errorCallback, remotePath, localPath, recursive));
 }
 
-Networking::Request *DropboxStorage::syncSaves(BoolCallback callback) {
+Networking::Request *DropboxStorage::syncSaves(BoolCallback callback, Networking::ErrorCallback errorCallback) {
-	//this is not the real syncSaves() implementation	
+	//this might be the real syncSaves() implementation
-	//"" is root in Dropbox, not "/"
+	return ConnMan.addRequest(new SavesSyncRequest(this, new Common::Callback<DropboxStorage, BoolResponse>(this, &DropboxStorage::printBool), getErrorPrintingCallback())); //TODO	
-	//this must create all these directories:
-	//return download("/remote/test.jpg", "local/a/b/c/d/test.jpg", 0);
-	/*
-	return downloadFolder(
-		"/not_flat", "local/not_flat_1_level/",
-		new Common::Callback<DropboxStorage, FileArrayResponse>(this, &DropboxStorage::printFiles),
-		false
-	);
-	*/
-	/*
-	debug("%s", ConfMan.get("savepath").c_str());
-	Common::StringArray arr = g_system->getSavefileManager()->listSavefiles("*");
-	for (uint32 i = 0; i < arr.size(); ++i) {
-		debug("%s", arr[i].c_str());
-	}
-	debug("EOL");
-	*/
-	//return upload("/remote/backslash", "C:\\Users\\Tkachov\\AppData\\Roaming\\ScummVM\\Saved games\\sword25.000", new Common::Callback<DropboxStorage, UploadResponse>(this, &DropboxStorage::printUploadStatus));
-	//return upload("/remote/slash", "C:/Users/Tkachov/AppData/Roaming/ScummVM/Saved games/sword25.000", new Common::Callback<DropboxStorage, UploadResponse>(this, &DropboxStorage::printUploadStatus));
-	return ConnMan.addRequest(new SavesSyncRequest(this, new Common::Callback<DropboxStorage, BoolResponse>(this, &DropboxStorage::printBool)));
-	//return upload("/remote/test4.bmp", "final.bmp", new Common::Callback<DropboxStorage, UploadResponse>(this, &DropboxStorage::printUploadStatus));
 }
 
-Networking::Request *DropboxStorage::info(StorageInfoCallback outerCallback) {
+Networking::Request *DropboxStorage::info(StorageInfoCallback outerCallback, Networking::ErrorCallback errorCallback) {
 	Networking::JsonCallback innerCallback = new Common::CallbackBridge<DropboxStorage, StorageInfoResponse, Networking::JsonResponse>(this, &DropboxStorage::infoInnerCallback, outerCallback);
-	Networking::CurlJsonRequest *request = new Networking::CurlJsonRequest(innerCallback, "https://api.dropboxapi.com/1/account/info");
+	Networking::CurlJsonRequest *request = new Networking::CurlJsonRequest(innerCallback, errorCallback, "https://api.dropboxapi.com/1/account/info");
 	request->addHeader("Authorization: Bearer " + _token);
 	return ConnMan.addRequest(request);
 	//that callback bridge wraps the outerCallback (passed in arguments from user) into innerCallback
@@ -216,8 +191,8 @@ Networking::Request *DropboxStorage::info(StorageInfoCallback outerCallback) {
 	//and then calls the outerCallback (which wants to receive StorageInfo, not void *)
 }
 
-void DropboxStorage::infoInnerCallback(StorageInfoCallback outerCallback, Networking::JsonResponse pair) {
+void DropboxStorage::infoInnerCallback(StorageInfoCallback outerCallback, Networking::JsonResponse response) {
-	Common::JSONValue *json = pair.value;
+	Common::JSONValue *json = response.value;
 	if (!json) {
 		warning("NULL passed instead of JSON");
 		delete outerCallback;
@@ -241,11 +216,11 @@ void DropboxStorage::infoInnerCallback(StorageInfoCallback outerCallback, Networ
 	delete json;
 }
 
-void DropboxStorage::infoMethodCallback(StorageInfoResponse pair) {
+void DropboxStorage::infoMethodCallback(StorageInfoResponse response) {
 	debug("\nStorage info:");
-	debug("User name: %s", pair.value.name().c_str());
+	debug("User name: %s", response.value.name().c_str());
-	debug("Email: %s", pair.value.email().c_str());
+	debug("Email: %s", response.value.email().c_str());
-	debug("Disk usage: %u/%u", pair.value.used(), pair.value.available());
+	debug("Disk usage: %u/%u", response.value.used(), response.value.available());
 }
 
 DropboxStorage *DropboxStorage::loadFromConfig(Common::String keyPrefix) {
@@ -298,7 +273,7 @@ void DropboxStorage::authThroughConsole() {
 
 void DropboxStorage::getAccessToken(Common::String code) {
 	Networking::JsonCallback callback = new Common::GlobalFunctionCallback<Networking::JsonResponse>(saveAccessTokenCallback);
-	Networking::CurlJsonRequest *request = new Networking::CurlJsonRequest(callback, "https://api.dropboxapi.com/1/oauth2/token");
+	Networking::CurlJsonRequest *request = new Networking::CurlJsonRequest(callback, nullptr, "https://api.dropboxapi.com/1/oauth2/token"); //TODO
 	request->addPostField("code=" + code);
 	request->addPostField("grant_type=authorization_code");
 	request->addPostField("client_id=" + Common::String(KEY));

backends/cloud/dropbox/dropboxstorage.h

@@ -45,9 +45,12 @@ class DropboxStorage: public Cloud::Storage {
 	/** Constructs StorageInfo based on JSON response from cloud. */
 	void infoInnerCallback(StorageInfoCallback outerCallback, Networking::JsonResponse json);
 
-	void printFiles(FileArrayResponse pair);
+	void printFiles(FileArrayResponse response);
-	void printBool(BoolResponse pair);
+	void printBool(BoolResponse response);
-	void printUploadStatus(UploadResponse pair);
+	void printStorageFile(UploadResponse response);
+	void printErrorResponse(Networking::ErrorResponse error);
+
+	Networking::ErrorCallback getErrorPrintingCallback();
 
 public:	
 	virtual ~DropboxStorage();
@@ -68,38 +71,38 @@ public:
 	/** Public Cloud API comes down there. */
 
 	/** Returns ListDirectoryStatus struct with list of files. */
-	virtual Networking::Request *listDirectory(Common::String path, ListDirectoryCallback callback, bool recursive = false);
+	virtual Networking::Request *listDirectory(Common::String path, ListDirectoryCallback callback, Networking::ErrorCallback errorCallback, bool recursive = false);
 	
 	/** Returns UploadStatus struct with info about uploaded file. */
-	virtual Networking::Request *upload(Common::String path, Common::SeekableReadStream *contents, UploadCallback callback);
+	virtual Networking::Request *upload(Common::String path, Common::SeekableReadStream *contents, UploadCallback callback, Networking::ErrorCallback errorCallback);
-	virtual Networking::Request *upload(Common::String remotePath, Common::String localPath, UploadCallback callback);
+	virtual Networking::Request *upload(Common::String remotePath, Common::String localPath, UploadCallback callback, Networking::ErrorCallback errorCallback);
 
 	/** Returns pointer to Networking::NetworkReadStream. */
-	virtual Networking::Request *streamFile(Common::String path, Networking::NetworkReadStreamCallback callback);
+	virtual Networking::Request *streamFile(Common::String path, Networking::NetworkReadStreamCallback callback, Networking::ErrorCallback errorCallback);
 
 	/** Calls the callback when finished. */
-	virtual Networking::Request *download(Common::String remotePath, Common::String localPath, BoolCallback callback);
+	virtual Networking::Request *download(Common::String remotePath, Common::String localPath, BoolCallback callback, Networking::ErrorCallback errorCallback);
 
 	/** Returns Common::Array<StorageFile> with list of files, which were not downloaded. */
-	virtual Networking::Request *downloadFolder(Common::String remotePath, Common::String localPath, FileArrayCallback callback, bool recursive = false);
+	virtual Networking::Request *downloadFolder(Common::String remotePath, Common::String localPath, FileArrayCallback callback, Networking::ErrorCallback errorCallback, bool recursive = false);
 
 	/** Calls the callback when finished. */
-	virtual Networking::Request *remove(Common::String path, BoolCallback callback) { return nullptr; } //TODO
+	virtual Networking::Request *remove(Common::String path, BoolCallback callback, Networking::ErrorCallback errorCallback) { return nullptr; } //TODO
 
 	/** Calls the callback when finished. */
-	virtual Networking::Request *syncSaves(BoolCallback callback);
+	virtual Networking::Request *syncSaves(BoolCallback callback, Networking::ErrorCallback errorCallback);
 
 	/** Calls the callback when finished. */
-	virtual Networking::Request *createDirectory(Common::String path, BoolCallback callback) { return nullptr; } //TODO
+	virtual Networking::Request *createDirectory(Common::String path, BoolCallback callback, Networking::ErrorCallback errorCallback) { return nullptr; } //TODO
 
 	/** Calls the callback when finished. */
-	virtual Networking::Request *touch(Common::String path, BoolCallback callback) { return nullptr; } //TODO
+	virtual Networking::Request *touch(Common::String path, BoolCallback callback, Networking::ErrorCallback errorCallback) { return nullptr; } //TODO
 
 	/** Returns the StorageInfo struct. */
-	virtual Networking::Request *info(StorageInfoCallback callback);
+	virtual Networking::Request *info(StorageInfoCallback callback, Networking::ErrorCallback errorCallback);
 
 	/** This method is passed into info(). (Temporary) */
-	void infoMethodCallback(StorageInfoResponse pair);
+	void infoMethodCallback(StorageInfoResponse response);
 
 	/** Returns whether saves sync process is running. */
 	virtual bool isSyncing() { return false; } //TODO

backends/cloud/dropbox/dropboxuploadrequest.cpp

@@ -32,8 +32,8 @@
 namespace Cloud {
 namespace Dropbox {
 
-DropboxUploadRequest::DropboxUploadRequest(Common::String token, Common::String path, Common::SeekableReadStream *contents, Storage::UploadCallback callback):
+DropboxUploadRequest::DropboxUploadRequest(Common::String token, Common::String path, Common::SeekableReadStream *contents, Storage::UploadCallback callback, Networking::ErrorCallback ecb):
-	Networking::Request(0), _token(token), _savePath(path), _contentsStream(contents), _uploadCallback(callback),
+	Networking::Request(nullptr, ecb), _token(token), _savePath(path), _contentsStream(contents), _uploadCallback(callback),
 	_workingRequest(nullptr), _ignoreCallback(false) {
 	start();
 }
@@ -50,7 +50,7 @@ void DropboxUploadRequest::start() {
 	if (_workingRequest) _workingRequest->finish();
 	if (!_contentsStream->seek(0)) {
 		warning("DropboxUploadRequest: cannot restart because stream couldn't seek(0)");
-		finish();
+		finishError(Networking::ErrorResponse(this, false, true, "", -1));
 	}
 	_ignoreCallback = false;
 
@@ -97,8 +97,9 @@ void DropboxUploadRequest::uploadNextPart() {
 	}
 	
 	Common::JSONValue value(jsonRequestParameters);
-	Networking::JsonCallback innerCallback = new Common::Callback<DropboxUploadRequest, Networking::JsonResponse>(this, &DropboxUploadRequest::partUploadedCallback);
+	Networking::JsonCallback callback = new Common::Callback<DropboxUploadRequest, Networking::JsonResponse>(this, &DropboxUploadRequest::partUploadedCallback);
-	Networking::CurlJsonRequest *request = new Networking::CurlJsonRequest(innerCallback, url);
+	Networking::ErrorCallback failureCallback = new Common::Callback<DropboxUploadRequest, Networking::ErrorResponse>(this, &DropboxUploadRequest::partUploadedErrorCallback);
+	Networking::CurlJsonRequest *request = new Networking::CurlJsonRequest(callback, failureCallback, url);
 	request->addHeader("Authorization: Bearer " + _token);
 	request->addHeader("Content-Type: application/octet-stream");	
 	request->addHeader("Dropbox-API-Arg: " + Common::JSON::stringify(&value));	
@@ -110,46 +111,45 @@ void DropboxUploadRequest::uploadNextPart() {
 	_workingRequest = ConnMan.addRequest(request);
 }
 
-void DropboxUploadRequest::partUploadedCallback(Networking::JsonResponse pair) {
+void DropboxUploadRequest::partUploadedCallback(Networking::JsonResponse response) {
-	if (_ignoreCallback) return;
+	debug("partUploadedCallback");
 	_workingRequest = nullptr;
+	if (_ignoreCallback) return;
 
-	UploadStatus status;
+	Networking::ErrorResponse error(this, false, true, "", -1);
-	Networking::CurlJsonRequest *rq = (Networking::CurlJsonRequest *)pair.request;
+	Networking::CurlJsonRequest *rq = (Networking::CurlJsonRequest *)response.request;
 	if (rq && rq->getNetworkReadStream())
-		status.httpResponseCode = rq->getNetworkReadStream()->httpResponseCode();
+		error.httpResponseCode = rq->getNetworkReadStream()->httpResponseCode();
 
-	Common::JSONValue *json = pair.value;
+	Common::JSONValue *json = response.value;
 	if (json) {
 		bool needsFinishRequest = false;
 
 		if (json->isObject()) {
-			Common::JSONObject response = json->asObject();
+			Common::JSONObject object = json->asObject();
 
 			//debug("%s", json->stringify(true).c_str());
 
-			if (response.contains("error") || response.contains("error_summary")) {
+			if (object.contains("error") || object.contains("error_summary")) {
-				warning("Dropbox returned error: %s", response.getVal("error_summary")->asString().c_str());
+				warning("Dropbox returned error: %s", object.getVal("error_summary")->asString().c_str());
 				delete json;
-				status.failed = true;
+				error.response = json->stringify(true);
-				status.response = json->stringify(true);
+				finishError(error);
-				finishUpload(status);
 				return;
 			}
 
-			if (response.contains("server_modified")) {
+			if (object.contains("server_modified")) {
 				//finished
-				Common::String path = response.getVal("path_lower")->asString();				
+				Common::String path = object.getVal("path_lower")->asString();
-				uint32 size = response.getVal("size")->asIntegerNumber();
+				uint32 size = object.getVal("size")->asIntegerNumber();
-				uint32 timestamp = ISO8601::convertToTimestamp(response.getVal("server_modified")->asString());				
+				uint32 timestamp = ISO8601::convertToTimestamp(object.getVal("server_modified")->asString());
-				status.file = StorageFile(path, size, timestamp, false);
+				finishSuccess(StorageFile(path, size, timestamp, false));
-				finishUpload(status);
 				return;
 			}
 
 			if (_sessionId == "") {
-				if (response.contains("session_id"))
+				if (object.contains("session_id"))
-					_sessionId = response.getVal("session_id")->asString();
+					_sessionId = object.getVal("session_id")->asString();
 				else
 					warning("no session_id found in Dropbox's response");
 				needsFinishRequest = true;
@@ -157,36 +157,33 @@ void DropboxUploadRequest::partUploadedCallback(Networking::JsonResponse pair) {
 		}
 
 		if (!needsFinishRequest && (_contentsStream->eos() || _contentsStream->pos() >= _contentsStream->size() - 1)) {			
-			if (status.file.name() == "") {
+			warning("no file info to return");
-				status.file = StorageFile(_savePath, 0, 0, false);
+			finishSuccess(StorageFile(_savePath, 0, 0, false));
-				warning("no file info to put into status");
-			}
-			finishUpload(status);
 		} else {
 			uploadNextPart();
 		}
 	} else {
 		warning("null, not json");		
-		status.failed = true;
+		finishError(error);
-		finishUpload(status);
 	}
 
 	delete json;
 }
 
+void DropboxUploadRequest::partUploadedErrorCallback(Networking::ErrorResponse error) {
+	debug("partUploadedErrorCallback");
+	_workingRequest = nullptr;
+	if (_ignoreCallback) return;
+	finishError(error);
+}
+
 void DropboxUploadRequest::handle() {}
 
 void DropboxUploadRequest::restart() { start(); }
 
-void DropboxUploadRequest::finish() {
+void DropboxUploadRequest::finishSuccess(StorageFile file) {
-	UploadStatus status;
+	Request::finishSuccess();
-	status.interrupted = true;
+	if (_uploadCallback) (*_uploadCallback)(Storage::UploadResponse(this, file));
-	finishUpload(status);
-}
-
-void DropboxUploadRequest::finishUpload(UploadStatus status) {
-	Request::finish();
-	if (_uploadCallback) (*_uploadCallback)(Storage::UploadResponse(this, status));
 }
 
 } // End of namespace Dropbox

backends/cloud/dropbox/dropboxuploadrequest.h

@@ -42,16 +42,16 @@ class DropboxUploadRequest: public Networking::Request {
 	
 	void start();
 	void uploadNextPart();
-	void partUploadedCallback(Networking::JsonResponse pair);
+	void partUploadedCallback(Networking::JsonResponse response);
-	void finishUpload(UploadStatus status);
+	void partUploadedErrorCallback(Networking::ErrorResponse error);
+	void finishSuccess(StorageFile status);
 
 public:
-	DropboxUploadRequest(Common::String token, Common::String path, Common::SeekableReadStream *contents, Storage::UploadCallback callback);
+	DropboxUploadRequest(Common::String token, Common::String path, Common::SeekableReadStream *contents, Storage::UploadCallback callback, Networking::ErrorCallback ecb);
 	virtual ~DropboxUploadRequest();
 
 	virtual void handle();
 	virtual void restart();
-	virtual void finish();
 };
 
 } // End of namespace Dropbox

backends/cloud/folderdownloadrequest.cpp

@@ -25,8 +25,8 @@
 
 namespace Cloud {
 
-FolderDownloadRequest::FolderDownloadRequest(Storage *storage, Storage::FileArrayCallback callback, Common::String remoteDirectoryPath, Common::String localDirectoryPath, bool recursive):
+FolderDownloadRequest::FolderDownloadRequest(Storage *storage, Storage::FileArrayCallback callback, Networking::ErrorCallback ecb, Common::String remoteDirectoryPath, Common::String localDirectoryPath, bool recursive):
-	Request(nullptr), _storage(storage), _fileArrayCallback(callback),
+	Request(nullptr, ecb), _storage(storage), _fileArrayCallback(callback),
 	_remoteDirectoryPath(remoteDirectoryPath), _localDirectoryPath(localDirectoryPath), _recursive(recursive),
 	_workingRequest(nullptr), _ignoreCallback(false) {
 	start();
@@ -51,33 +51,39 @@ void FolderDownloadRequest::start() {
 	_workingRequest = _storage->listDirectory(
 		_remoteDirectoryPath,
 		new Common::Callback<FolderDownloadRequest, Storage::ListDirectoryResponse>(this, &FolderDownloadRequest::directoryListedCallback),
+		new Common::Callback<FolderDownloadRequest, Networking::ErrorResponse>(this, &FolderDownloadRequest::directoryListedErrorCallback),
 		_recursive
 	);
 }
 
-void FolderDownloadRequest::directoryListedCallback(Storage::ListDirectoryResponse pair) {
+void FolderDownloadRequest::directoryListedCallback(Storage::ListDirectoryResponse response) {
+	_workingRequest = nullptr;
 	if (_ignoreCallback) return;
-
+	_files = response.value;
-	ListDirectoryStatus status = pair.value;
-	if (status.failed || status.interrupted) {
-		finish();
-		return;
-	}
-	
-	_files = pair.value.files;
 	downloadNextFile();
 }
 
-void FolderDownloadRequest::fileDownloadedCallback(Storage::BoolResponse pair) {
+void FolderDownloadRequest::directoryListedErrorCallback(Networking::ErrorResponse error) {
+	_workingRequest = nullptr;
 	if (_ignoreCallback) return;
-	if (!pair.value) _failedFiles.push_back(_currentFile);
+	finishError(error);
+}
+
+void FolderDownloadRequest::fileDownloadedCallback(Storage::BoolResponse response) {
+	_workingRequest = nullptr;
+	if (_ignoreCallback) return;
+	if (!response.value) _failedFiles.push_back(_currentFile);
 	downloadNextFile();
 }
 
+void FolderDownloadRequest::fileDownloadedErrorCallback(Networking::ErrorResponse error) {
+	fileDownloadedCallback(Storage::BoolResponse(error.request, false));
+}
+
 void FolderDownloadRequest::downloadNextFile() {
 	do {
 		if (_files.empty()) {
-			finishFiles(_failedFiles);
+			finishSuccess(_failedFiles);
 			return;
 		}
 	
@@ -105,18 +111,17 @@ void FolderDownloadRequest::downloadNextFile() {
 	debug("%s -> %s", remotePath.c_str(), localPath.c_str());
 	_workingRequest = _storage->download(
 		remotePath, localPath,
-		new Common::Callback<FolderDownloadRequest, Storage::BoolResponse>(this, &FolderDownloadRequest::fileDownloadedCallback)		
+		new Common::Callback<FolderDownloadRequest, Storage::BoolResponse>(this, &FolderDownloadRequest::fileDownloadedCallback),
+		new Common::Callback<FolderDownloadRequest, Networking::ErrorResponse>(this, &FolderDownloadRequest::fileDownloadedErrorCallback)
 	);
 }
 
-void FolderDownloadRequest::finish() {
+void FolderDownloadRequest::handle() {}
-	//TODO: somehow indicate that request was interrupted
-	Common::Array<StorageFile> files;
-	finishFiles(files);
-}
 
-void FolderDownloadRequest::finishFiles(Common::Array<StorageFile> &files) {
+void FolderDownloadRequest::restart() { start(); }
-	Request::finish();
+
+void FolderDownloadRequest::finishSuccess(Common::Array<StorageFile> &files) {
+	Request::finishSuccess();
 	if (_fileArrayCallback) (*_fileArrayCallback)(Storage::FileArrayResponse(this, files));
 }
 

backends/cloud/folderdownloadrequest.h

@@ -40,17 +40,18 @@ class FolderDownloadRequest: public Networking::Request {
 	bool _ignoreCallback;
 
 	void start();
-	void directoryListedCallback(Storage::ListDirectoryResponse pair);
+	void directoryListedCallback(Storage::ListDirectoryResponse response);
-	void fileDownloadedCallback(Storage::BoolResponse pair);
+	void directoryListedErrorCallback(Networking::ErrorResponse error);
+	void fileDownloadedCallback(Storage::BoolResponse response);
+	void fileDownloadedErrorCallback(Networking::ErrorResponse error);
 	void downloadNextFile();
-	void finishFiles(Common::Array<StorageFile> &files);
+	void finishSuccess(Common::Array<StorageFile> &files);
 public:
-	FolderDownloadRequest(Storage *storage, Storage::FileArrayCallback callback, Common::String remoteDirectoryPath, Common::String localDirectoryPath, bool recursive);
+	FolderDownloadRequest(Storage *storage, Storage::FileArrayCallback callback, Networking::ErrorCallback ecb, Common::String remoteDirectoryPath, Common::String localDirectoryPath, bool recursive);
 	virtual ~FolderDownloadRequest();
 
-	virtual void handle() {}
+	virtual void handle();
-	virtual void restart() { start(); }
+	virtual void restart();	
-	virtual void finish();
 };
 
 } // End of namespace Cloud

backends/cloud/manager.cpp

@@ -110,9 +110,9 @@ Storage *Manager::getCurrentStorage() {
 	return nullptr;
 }
 
-void Manager::syncSaves(Storage::BoolCallback callback) {
+void Manager::syncSaves(Storage::BoolCallback callback, Networking::ErrorCallback errorCallback) {
 	Storage *storage = getCurrentStorage();
-	if (storage) storage->syncSaves(callback);
+	if (storage) storage->syncSaves(callback, errorCallback);
 }
 
 } // End of namespace Cloud

backends/cloud/manager.h

@@ -42,7 +42,7 @@ public:
 	virtual void addStorage(Cloud::Storage *storage, bool makeCurrent = true, bool saveConfig = true);
 
 	virtual Storage *getCurrentStorage();
-	virtual void syncSaves(Storage::BoolCallback callback);
+	virtual void syncSaves(Storage::BoolCallback callback, Networking::ErrorCallback errorCallback);
 };
 
 } // End of namespace Cloud

backends/cloud/onedrive/onedrivelistdirectoryrequest.cpp

@@ -31,8 +31,8 @@
 namespace Cloud {
 namespace OneDrive {
 
-OneDriveListDirectoryRequest::OneDriveListDirectoryRequest(OneDriveStorage *storage, Common::String path, Storage::ListDirectoryCallback cb, bool recursive):
+OneDriveListDirectoryRequest::OneDriveListDirectoryRequest(OneDriveStorage *storage, Common::String path, Storage::ListDirectoryCallback cb, Networking::ErrorCallback ecb, bool recursive):
-	Networking::Request(0),
+	Networking::Request(nullptr, ecb),
 	_requestedPath(path), _requestedRecursive(recursive), _storage(storage), _listDirectoryCallback(cb),
 	_workingRequest(nullptr), _ignoreCallback(false) {
 	start();
@@ -55,12 +55,12 @@ void OneDriveListDirectoryRequest::start() {
 	_ignoreCallback = false;
 
 	_directoriesQueue.push_back(_requestedPath);
-	listNextDirectory(_files);
+	listNextDirectory();
 }
 
-void OneDriveListDirectoryRequest::listNextDirectory(ListDirectoryStatus status) {
+void OneDriveListDirectoryRequest::listNextDirectory() {
 	if (_directoriesQueue.empty()) {
-		finishStatus(status);
+		finishSuccess(_files);
 		return;
 	}
 
@@ -78,36 +78,37 @@ void OneDriveListDirectoryRequest::listNextDirectory(ListDirectoryStatus status)
 
 void OneDriveListDirectoryRequest::makeRequest(Common::String url) {	
 	Networking::JsonCallback callback = new Common::Callback<OneDriveListDirectoryRequest, Networking::JsonResponse>(this, &OneDriveListDirectoryRequest::listedDirectoryCallback);
-	Networking::CurlJsonRequest *request = new OneDriveTokenRefresher(_storage, callback, url.c_str());
+	Networking::ErrorCallback failureCallback = new Common::Callback<OneDriveListDirectoryRequest, Networking::ErrorResponse>(this, &OneDriveListDirectoryRequest::listedDirectoryErrorCallback);
+	Networking::CurlJsonRequest *request = new OneDriveTokenRefresher(_storage, callback, failureCallback, url.c_str());
 	request->addHeader("Authorization: Bearer " + _storage->accessToken());
 	_workingRequest = ConnMan.addRequest(request);
 }
 
-void OneDriveListDirectoryRequest::listedDirectoryCallback(Networking::JsonResponse pair) {
+void OneDriveListDirectoryRequest::listedDirectoryCallback(Networking::JsonResponse response) {
 	_workingRequest = nullptr;
-	Common::JSONValue *json = pair.value;
+	Common::JSONValue *json = response.value;
 
 	if (_ignoreCallback) {
 		delete json;
 		return;
 	}
 
-	ListDirectoryStatus status(_files);
+	Networking::ErrorResponse error(this);
-	Networking::CurlJsonRequest *rq = (Networking::CurlJsonRequest *)pair.request;
+	Networking::CurlJsonRequest *rq = (Networking::CurlJsonRequest *)response.request;
 	if (rq && rq->getNetworkReadStream())
-		status.httpResponseCode = rq->getNetworkReadStream()->httpResponseCode();
+		error.httpResponseCode = rq->getNetworkReadStream()->httpResponseCode();
 
 	if (!json) {
-		status.failed = true;
+		error.failed = true;
-		finishStatus(status);
+		finishError(error);
 		return;
 	}
 
-	Common::JSONObject response = json->asObject();		
+	Common::JSONObject object = json->asObject();		
 	
 	//TODO: check that ALL keys exist AND HAVE RIGHT TYPE to avoid segfaults
 
-	Common::JSONArray items = response.getVal("value")->asArray();
+	Common::JSONArray items = object.getVal("value")->asArray();
 	for (uint32 i = 0; i < items.size(); ++i) {
 		Common::JSONObject item = items[i]->asObject();	
 
@@ -123,26 +124,29 @@ void OneDriveListDirectoryRequest::listedDirectoryCallback(Networking::JsonRespo
 		}
 	}
 
-	bool hasMore = response.contains("@odata.nextLink");
+	bool hasMore = object.contains("@odata.nextLink");
 	if (hasMore) {
-		makeRequest(response.getVal("@odata.nextLink")->asString());
+		makeRequest(object.getVal("@odata.nextLink")->asString());
 	} else {
-		listNextDirectory(status);
+		listNextDirectory();
 	}
 
 	delete json;
 }
 
-void OneDriveListDirectoryRequest::finish() {	
+void OneDriveListDirectoryRequest::listedDirectoryErrorCallback(Networking::ErrorResponse error) {
-	Common::Array<StorageFile> files;
+	_workingRequest = nullptr;
-	ListDirectoryStatus status(files);
+	if (_ignoreCallback) return;
-	status.interrupted = true;
+	finishError(error);
-	finishStatus(status);
 }
 
-void OneDriveListDirectoryRequest::finishStatus(ListDirectoryStatus status) {
+void OneDriveListDirectoryRequest::handle() {}
-	Request::finish();
+
-	if (_listDirectoryCallback) (*_listDirectoryCallback)(Storage::ListDirectoryResponse(this, status));
+void OneDriveListDirectoryRequest::restart() { start(); }
+
+void OneDriveListDirectoryRequest::finishSuccess(Common::Array<StorageFile> &files) {
+	Request::finishSuccess();
+	if (_listDirectoryCallback) (*_listDirectoryCallback)(Storage::ListDirectoryResponse(this, files));
 }
 
 } // End of namespace OneDrive

backends/cloud/onedrive/onedrivelistdirectoryrequest.h

@@ -45,17 +45,17 @@ class OneDriveListDirectoryRequest: public Networking::Request {
 	bool _ignoreCallback;
 
 	void start();
-	void listNextDirectory(ListDirectoryStatus status);
+	void listNextDirectory();
-	void listedDirectoryCallback(Networking::JsonResponse pair);
+	void listedDirectoryCallback(Networking::JsonResponse response);
+	void listedDirectoryErrorCallback(Networking::ErrorResponse error);
 	void makeRequest(Common::String url);
-	void finishStatus(ListDirectoryStatus status);
+	void finishSuccess(Common::Array<StorageFile> &files);
 public:
-	OneDriveListDirectoryRequest(OneDriveStorage *storage, Common::String path, Storage::ListDirectoryCallback cb, bool recursive = false);
+	OneDriveListDirectoryRequest(OneDriveStorage *storage, Common::String path, Storage::ListDirectoryCallback cb, Networking::ErrorCallback ecb, bool recursive = false);
 	virtual ~OneDriveListDirectoryRequest();
 
-	virtual void handle() {}
+	virtual void handle();
-	virtual void restart() { start(); }
+	virtual void restart();
-	virtual void finish();
 };
 
 } // End of namespace OneDrive

backends/cloud/onedrive/onedrivestorage.cpp

@@ -74,7 +74,7 @@ void OneDriveStorage::getAccessToken(BoolCallback callback, Common::String code)
 	}
 
 	Networking::JsonCallback innerCallback = new Common::CallbackBridge<OneDriveStorage, BoolResponse, Networking::JsonResponse>(this, &OneDriveStorage::tokenRefreshed, callback);
-	Networking::CurlJsonRequest *request = new Networking::CurlJsonRequest(innerCallback, "https://login.live.com/oauth20_token.srf");
+	Networking::CurlJsonRequest *request = new Networking::CurlJsonRequest(innerCallback, getErrorPrintingCallback(), "https://login.live.com/oauth20_token.srf"); //TODO
 	if (codeFlow) {
 		request->addPostField("code=" + code);
 		request->addPostField("grant_type=authorization_code");
@@ -88,8 +88,8 @@ void OneDriveStorage::getAccessToken(BoolCallback callback, Common::String code)
 	ConnMan.addRequest(request);
 }
 
-void OneDriveStorage::tokenRefreshed(BoolCallback callback, Networking::JsonResponse pair) {
+void OneDriveStorage::tokenRefreshed(BoolCallback callback, Networking::JsonResponse response) {
-	Common::JSONValue *json = pair.value;
+	Common::JSONValue *json = response.value;
 	if (!json) {
 		warning("OneDriveStorage: got NULL instead of JSON");
 		if (callback) (*callback)(BoolResponse(nullptr, false));
@@ -111,8 +111,8 @@ void OneDriveStorage::tokenRefreshed(BoolCallback callback, Networking::JsonResp
 	delete json;
 }
 
-void OneDriveStorage::codeFlowComplete(BoolResponse pair) {
+void OneDriveStorage::codeFlowComplete(BoolResponse response) {
-	if (!pair.value) {
+	if (!response.value) {
 		warning("OneDriveStorage: failed to get access token through code flow");
 		return;
 	}
@@ -130,8 +130,8 @@ void OneDriveStorage::saveConfig(Common::String keyPrefix) {
 	ConfMan.set(keyPrefix + "refresh_token", _refreshToken, "cloud");
 }
 
-void OneDriveStorage::printJson(Networking::JsonResponse pair) {
+void OneDriveStorage::printJson(Networking::JsonResponse response) {
-	Common::JSONValue *json = pair.value;
+	Common::JSONValue *json = response.value;
 	if (!json) {
 		warning("printJson: NULL");
 		return;
@@ -141,77 +141,85 @@ void OneDriveStorage::printJson(Networking::JsonResponse pair) {
 	delete json;
 }
 
-void OneDriveStorage::fileInfoCallback(Networking::NetworkReadStreamCallback outerCallback, Networking::JsonResponse pair) {
+void OneDriveStorage::fileInfoCallback(Networking::NetworkReadStreamCallback outerCallback, Networking::JsonResponse response) {
-	if (!pair.value) {
+	if (!response.value) {
 		warning("fileInfoCallback: NULL");
-		if (outerCallback) (*outerCallback)(Networking::NetworkReadStreamResponse(pair.request, 0));
+		if (outerCallback) (*outerCallback)(Networking::NetworkReadStreamResponse(response.request, 0));
 		return;
 	}
 
-	Common::JSONObject result = pair.value->asObject();
+	Common::JSONObject result = response.value->asObject();
 	if (result.contains("@content.downloadUrl")) {
 		const char *url = result.getVal("@content.downloadUrl")->asString().c_str();
 		if (outerCallback)
 			(*outerCallback)(Networking::NetworkReadStreamResponse(
-				pair.request,
+				response.request,
 				new Networking::NetworkReadStream(url, 0, "")
 			));
 	} else {
 		warning("downloadUrl not found in passed JSON");
-		debug("%s", pair.value->stringify().c_str());
+		debug("%s", response.value->stringify().c_str());
-		if (outerCallback) (*outerCallback)(Networking::NetworkReadStreamResponse(pair.request, 0));
+		if (outerCallback) (*outerCallback)(Networking::NetworkReadStreamResponse(response.request, 0));
 	}
-	delete pair.value;
+	delete response.value;
 }
 
-Networking::Request *OneDriveStorage::listDirectory(Common::String path, ListDirectoryCallback callback, bool recursive) {
+Networking::Request *OneDriveStorage::listDirectory(Common::String path, ListDirectoryCallback callback, Networking::ErrorCallback errorCallback, bool recursive) {
-	return ConnMan.addRequest(new OneDriveListDirectoryRequest(this, path, callback, recursive));
+	return ConnMan.addRequest(new OneDriveListDirectoryRequest(this, path, callback, errorCallback, recursive));
 }
 
 
-Networking::Request *OneDriveStorage::streamFile(Common::String path, Networking::NetworkReadStreamCallback outerCallback) {
+Networking::Request *OneDriveStorage::streamFile(Common::String path, Networking::NetworkReadStreamCallback outerCallback, Networking::ErrorCallback errorCallback) {
 	Common::String url = "https://api.onedrive.com/v1.0/drive/special/approot:/" + path;
 	Networking::JsonCallback innerCallback = new Common::CallbackBridge<OneDriveStorage, Networking::NetworkReadStreamResponse, Networking::JsonResponse>(this, &OneDriveStorage::fileInfoCallback, outerCallback);
-	Networking::CurlJsonRequest *request = new OneDriveTokenRefresher(this, innerCallback, url.c_str());
+	Networking::CurlJsonRequest *request = new OneDriveTokenRefresher(this, innerCallback, errorCallback, url.c_str());
 	request->addHeader("Authorization: Bearer " + _token);
 	return ConnMan.addRequest(request);
 }
 
-Networking::Request *OneDriveStorage::download(Common::String remotePath, Common::String localPath, BoolCallback callback) {
+Networking::Request *OneDriveStorage::download(Common::String remotePath, Common::String localPath, BoolCallback callback, Networking::ErrorCallback errorCallback) {
 	Common::DumpFile *f = new Common::DumpFile();
 	if (!f->open(localPath, true)) {
 		warning("OneDriveStorage: unable to open file to download into");
-		if (callback) (*callback)(BoolResponse(nullptr, false));
+		if (errorCallback) (*errorCallback)(Networking::ErrorResponse(nullptr, false, true, "", -1));
 		delete f;
 		return nullptr;
 	}
 
-	return ConnMan.addRequest(new DownloadRequest(this, callback, remotePath, f));
+	return ConnMan.addRequest(new DownloadRequest(this, callback, errorCallback, remotePath, f));
 }
 
 /** Returns Common::Array<StorageFile> with list of files, which were not downloaded. */
-Networking::Request *OneDriveStorage::downloadFolder(Common::String remotePath, Common::String localPath, FileArrayCallback callback, bool recursive) {
+Networking::Request *OneDriveStorage::downloadFolder(Common::String remotePath, Common::String localPath, FileArrayCallback callback, Networking::ErrorCallback errorCallback, bool recursive) {
-	return ConnMan.addRequest(new FolderDownloadRequest(this, callback, remotePath, localPath, recursive));
+	return ConnMan.addRequest(new FolderDownloadRequest(this, callback, errorCallback, remotePath, localPath, recursive));
 }
 
-void OneDriveStorage::fileDownloaded(BoolResponse pair) {
+void OneDriveStorage::fileDownloaded(BoolResponse response) {
-	if (pair.value) debug("file downloaded!");
+	if (response.value) debug("file downloaded!");
 	else debug("download failed!");
 }
 
-void OneDriveStorage::printFiles(FileArrayResponse pair) {
+void OneDriveStorage::printFiles(FileArrayResponse response) {
 	debug("files:");
-	Common::Array<StorageFile> &files = pair.value;
+	Common::Array<StorageFile> &files = response.value;
 	for (uint32 i = 0; i < files.size(); ++i)
 		debug("\t%s", files[i].path().c_str());
 }
 
-void OneDriveStorage::printBool(BoolResponse pair) {
+void OneDriveStorage::printBool(BoolResponse response) {
-	debug("bool: %s", pair.value ? "true" : "false");
+	debug("bool: %s", response.value ? "true" : "false");
 }
 
+void OneDriveStorage::printErrorResponse(Networking::ErrorResponse error) {
+	debug("error response (%s, %ld):", (error.failed ? "failed" : "interrupted"), error.httpResponseCode);
+	debug("%s", error.response.c_str());
+}
 
-Networking::Request *OneDriveStorage::syncSaves(BoolCallback callback) {
+Networking::ErrorCallback OneDriveStorage::getErrorPrintingCallback() {
+	return new Common::Callback<OneDriveStorage, Networking::ErrorResponse>(this, &OneDriveStorage::printErrorResponse);
+}
+
+Networking::Request *OneDriveStorage::syncSaves(BoolCallback callback, Networking::ErrorCallback errorCallback) {
 	//this is not the real syncSaves() implementation
 	/*
 	Networking::JsonCallback innerCallback = new Common::Callback<OneDriveStorage, Networking::RequestJsonPair>(this, &OneDriveStorage::printJson);
@@ -220,7 +228,7 @@ Networking::Request *OneDriveStorage::syncSaves(BoolCallback callback) {
 	return ConnMan.addRequest(request);
 	*/
 	//return downloadFolder("subfolder", "local/onedrive/subfolder_downloaded", new Common::Callback<OneDriveStorage, FileArrayResponse>(this, &OneDriveStorage::printFiles), false);
-	return ConnMan.addRequest(new SavesSyncRequest(this, new Common::Callback<OneDriveStorage, BoolResponse>(this, &OneDriveStorage::printBool)));
+	return ConnMan.addRequest(new SavesSyncRequest(this, new Common::Callback<OneDriveStorage, BoolResponse>(this, &OneDriveStorage::printBool), getErrorPrintingCallback())); //TODO
 }
 
 OneDriveStorage *OneDriveStorage::loadFromConfig(Common::String keyPrefix) {

backends/cloud/onedrive/onedrivestorage.h

@@ -46,15 +46,18 @@ class OneDriveStorage: public Cloud::Storage {
 	 */
 	OneDriveStorage(Common::String code);
 
-	void tokenRefreshed(BoolCallback callback, Networking::JsonResponse pair);
+	void tokenRefreshed(BoolCallback callback, Networking::JsonResponse response);
-	void codeFlowComplete(BoolResponse pair);
+	void codeFlowComplete(BoolResponse response);
 
-	void printJson(Networking::JsonResponse pair);
+	void printJson(Networking::JsonResponse response);
-	void fileDownloaded(BoolResponse pair);
+	void fileDownloaded(BoolResponse response);
-	void printFiles(FileArrayResponse pair);
+	void printFiles(FileArrayResponse response);
-	void printBool(BoolResponse pair);
+	void printBool(BoolResponse response);
+	void printErrorResponse(Networking::ErrorResponse error);
 
-	void fileInfoCallback(Networking::NetworkReadStreamCallback outerCallback, Networking::JsonResponse pair);
+	Networking::ErrorCallback getErrorPrintingCallback();
+
+	void fileInfoCallback(Networking::NetworkReadStreamCallback outerCallback, Networking::JsonResponse response);
 public:	
 	virtual ~OneDriveStorage();
 
@@ -74,35 +77,35 @@ public:
 	/** Public Cloud API comes down there. */
 
 	/** Returns ListDirectoryStatus struct with list of files. */
-	virtual Networking::Request *listDirectory(Common::String path, ListDirectoryCallback callback, bool recursive = false);
+	virtual Networking::Request *listDirectory(Common::String path, ListDirectoryCallback callback, Networking::ErrorCallback errorCallback, bool recursive = false);
 
 	/** Returns UploadStatus struct with info about uploaded file. */
-	virtual Networking::Request *upload(Common::String path, Common::SeekableReadStream *contents, UploadCallback callback) { return nullptr; } //TODO
+	virtual Networking::Request *upload(Common::String path, Common::SeekableReadStream *contents, UploadCallback callback, Networking::ErrorCallback errorCallback) { return nullptr; } //TODO
-	virtual Networking::Request *upload(Common::String remotePath, Common::String localPath, UploadCallback callback) { return nullptr; }
+	virtual Networking::Request *upload(Common::String remotePath, Common::String localPath, UploadCallback callback, Networking::ErrorCallback errorCallback) { return nullptr; } //TODO
 
 	/** Returns pointer to Networking::NetworkReadStream. */
-	virtual Networking::Request *streamFile(Common::String path, Networking::NetworkReadStreamCallback callback);
+	virtual Networking::Request *streamFile(Common::String path, Networking::NetworkReadStreamCallback callback, Networking::ErrorCallback errorCallback);
 
 	/** Calls the callback when finished. */
-	virtual Networking::Request *download(Common::String remotePath, Common::String localPath, BoolCallback callback);
+	virtual Networking::Request *download(Common::String remotePath, Common::String localPath, BoolCallback callback, Networking::ErrorCallback errorCallback);
 
 	/** Returns Common::Array<StorageFile> with list of files, which were not downloaded. */
-	virtual Networking::Request *downloadFolder(Common::String remotePath, Common::String localPath, FileArrayCallback callback, bool recursive = false);
+	virtual Networking::Request *downloadFolder(Common::String remotePath, Common::String localPath, FileArrayCallback callback, Networking::ErrorCallback errorCallback, bool recursive = false);
 
 	/** Calls the callback when finished. */
-	virtual Networking::Request *remove(Common::String path, BoolCallback callback) { return nullptr; } //TODO
+	virtual Networking::Request *remove(Common::String path, BoolCallback callback, Networking::ErrorCallback errorCallback) { return nullptr; } //TODO
 
 	/** Calls the callback when finished. */
-	virtual Networking::Request *syncSaves(BoolCallback callback);
+	virtual Networking::Request *syncSaves(BoolCallback callback, Networking::ErrorCallback errorCallback);
 
 	/** Calls the callback when finished. */
-	virtual Networking::Request *createDirectory(Common::String path, BoolCallback callback) { return nullptr; } //TODO
+	virtual Networking::Request *createDirectory(Common::String path, BoolCallback callback, Networking::ErrorCallback errorCallback) { return nullptr; } //TODO
 
 	/** Calls the callback when finished. */
-	virtual Networking::Request *touch(Common::String path, BoolCallback callback) { return nullptr; } //TODO
+	virtual Networking::Request *touch(Common::String path, BoolCallback callback, Networking::ErrorCallback errorCallback) { return nullptr; } //TODO
 
 	/** Returns the StorageInfo struct. */
-	virtual Networking::Request *info(StorageInfoCallback callback) { return nullptr; } //TODO
+	virtual Networking::Request *info(StorageInfoCallback callback, Networking::ErrorCallback errorCallback) { return nullptr; } //TODO
 
 	/** Returns whether saves sync process is running. */
 	virtual bool isSyncing() { return false; } //TODO

backends/cloud/onedrive/onedrivetokenrefresher.cpp

@@ -31,16 +31,16 @@
 namespace Cloud {
 namespace OneDrive {
 
-OneDriveTokenRefresher::OneDriveTokenRefresher(OneDriveStorage *parent, Networking::JsonCallback callback, const char *url):
+OneDriveTokenRefresher::OneDriveTokenRefresher(OneDriveStorage *parent, Networking::JsonCallback callback, Networking::ErrorCallback ecb, const char *url):
-	CurlJsonRequest(callback, url), _parentStorage(parent) {}
+	CurlJsonRequest(callback, ecb, url), _parentStorage(parent) {}
 
 OneDriveTokenRefresher::~OneDriveTokenRefresher() {}
 
-void OneDriveTokenRefresher::tokenRefreshed(Storage::BoolResponse pair) {
+void OneDriveTokenRefresher::tokenRefreshed(Storage::BoolResponse response) {
-	if (!pair.value) {
+	if (!response.value) {
 		//failed to refresh token, notify user with NULL in original callback
 		warning("OneDriveTokenRefresher: failed to refresh token");
-		finish();
+		finishError(Networking::ErrorResponse(this, false, true, "", -1));
 		return;
 	}
 
@@ -56,11 +56,10 @@ void OneDriveTokenRefresher::tokenRefreshed(Storage::BoolResponse pair) {
 	retry(0);
 }
 
-void OneDriveTokenRefresher::finishJson(Common::JSONValue *json) {	
+void OneDriveTokenRefresher::finishSuccess(Common::JSONValue *json) {
 	if (!json) {
-		//notify user of failure
+		//that's probably not an error (200 OK)
-		warning("OneDriveTokenRefresher: got NULL instead of JSON");
+		CurlJsonRequest::finishSuccess(nullptr);
-		CurlJsonRequest::finishJson(nullptr);
 		return;
 	}
 
@@ -74,19 +73,26 @@ void OneDriveTokenRefresher::finishJson(Common::JSONValue *json) {
 		Common::JSONObject error = result.getVal("error")->asObject();
 		bool irrecoverable = true;
 
+		Common::String code, message;
 		if (error.contains("code")) {
-			Common::String code = error.getVal("code")->asString();
+			code = error.getVal("code")->asString();
 			debug("code = %s", code.c_str());			
-			//if (code == "itemNotFound") irrecoverable = true;
 		}
 
 		if (error.contains("message")) {
-			Common::String message = error.getVal("message")->asString();
+			message = error.getVal("message")->asString();
 			debug("message = %s", message.c_str());
 		}
 
+		//determine whether token refreshing would help in this situation
+		if (code == "itemNotFound") {
+			if (message.contains("application ID"))
+				irrecoverable = false;
+		}
+
 		if (irrecoverable) {			
-			CurlJsonRequest::finishJson(nullptr);
+			finishError(Networking::ErrorResponse(this, false, true, json->stringify(true), -1)); //TODO: httpCode
+			delete json;
 			return;
 		}
 
@@ -97,7 +103,7 @@ void OneDriveTokenRefresher::finishJson(Common::JSONValue *json) {
 	}
 
 	//notify user of success
-	CurlJsonRequest::finishJson(json);
+	CurlJsonRequest::finishSuccess(json);
 }
 
 void OneDriveTokenRefresher::setHeaders(Common::Array<Common::String> &headers) {	
@@ -108,6 +114,10 @@ void OneDriveTokenRefresher::setHeaders(Common::Array<Common::String> &headers)
 		CurlJsonRequest::addHeader(headers[i]);
 }
 
+void OneDriveTokenRefresher::addHeader(Common::String header) {
+	_headers.push_back(header);
+	CurlJsonRequest::addHeader(header);
+}
 
 } // End of namespace OneDrive
 } // End of namespace Cloud

backends/cloud/onedrive/onedrivetokenrefresher.h

@@ -35,19 +35,15 @@ class OneDriveTokenRefresher: public Networking::CurlJsonRequest {
 	OneDriveStorage *_parentStorage;
 	Common::Array<Common::String> _headers;	
 	
-	void tokenRefreshed(Storage::BoolResponse pair);
+	void tokenRefreshed(Storage::BoolResponse response);
 
-	virtual void finishJson(Common::JSONValue *json);
+	virtual void finishSuccess(Common::JSONValue *json);
 public:	
-	OneDriveTokenRefresher(OneDriveStorage *parent, Networking::JsonCallback callback, const char *url);
+	OneDriveTokenRefresher(OneDriveStorage *parent, Networking::JsonCallback callback, Networking::ErrorCallback ecb, const char *url);
 	virtual ~OneDriveTokenRefresher();
 
 	virtual void setHeaders(Common::Array<Common::String> &headers);
-
+	virtual void addHeader(Common::String header);
-	virtual void addHeader(Common::String header) {
-		_headers.push_back(header);
-		CurlJsonRequest::addHeader(header);
-	}
 };
 
 } // End of namespace OneDrive

backends/cloud/savessyncrequest.cpp

@@ -32,8 +32,8 @@ namespace Cloud {
 
 const char *SavesSyncRequest::TIMESTAMPS_FILENAME = "timestamps";
 
-SavesSyncRequest::SavesSyncRequest(Storage *storage, Storage::BoolCallback callback):
+SavesSyncRequest::SavesSyncRequest(Storage *storage, Storage::BoolCallback callback, Networking::ErrorCallback ecb):
-	Request(nullptr), _storage(storage), _boolCallback(callback),
+	Request(nullptr, ecb), _storage(storage), _boolCallback(callback),
 	_workingRequest(nullptr), _ignoreCallback(false) {
 	start();
 }
@@ -59,48 +59,35 @@ void SavesSyncRequest::start() {
 	loadTimestamps();
 
 	//list saves directory
-	_workingRequest = _storage->listDirectory("/saves", new Common::Callback<SavesSyncRequest, Storage::ListDirectoryResponse>(this, &SavesSyncRequest::directoryListedCallback));
+	_workingRequest = _storage->listDirectory(
+		"/saves",
+		new Common::Callback<SavesSyncRequest, Storage::ListDirectoryResponse>(this, &SavesSyncRequest::directoryListedCallback),
+		new Common::Callback<SavesSyncRequest, Networking::ErrorResponse>(this, &SavesSyncRequest::directoryListedErrorCallback)
+	);
 }
 
-void SavesSyncRequest::directoryListedCallback(Storage::ListDirectoryResponse pair) {
+void SavesSyncRequest::directoryListedCallback(Storage::ListDirectoryResponse response) {
 	_workingRequest = nullptr;
 	if (_ignoreCallback) return;
 
-	ListDirectoryStatus status = pair.value;
+	Common::HashMap<Common::String, bool> localFileNotAvailableInCloud;
-	bool irrecoverable = status.interrupted || status.failed;
+	for (Common::HashMap<Common::String, uint32>::iterator i = _localFilesTimestamps.begin(); i != _localFilesTimestamps.end(); ++i) {		
-	if (status.failed) {
+		localFileNotAvailableInCloud[i->_key] = true;
-		Common::JSONValue *value = Common::JSON::parse(status.response.c_str());
-		if (value) {
-			if (value->isObject()) {
-				Common::JSONObject object = value->asObject();
-				//Dropbox-related error:
-				if (object.contains("error_summary")) {
-					Common::String summary = object.getVal("error_summary")->asString();
-					if (summary.contains("not_found")) {
-						//oh how lucky we are! It's just user don't have /cloud/ folder yet!
-						irrecoverable = false;
-					}
-				}
-			}
-			delete value;
-		}
-	}
-
-	if (irrecoverable) {
-		finishBool(false);
-		return;
 	}
 
 	//determine which files to download and which files to upload
-	Common::Array<StorageFile> &remoteFiles = status.files;
+	Common::Array<StorageFile> &remoteFiles = response.value;
 	for (uint32 i = 0; i < remoteFiles.size(); ++i) {
 		StorageFile &file = remoteFiles[i];
 		if (file.isDirectory()) continue;
 		if (file.name() == TIMESTAMPS_FILENAME) continue;
+
 		Common::String name = file.name();
 		if (!_localFilesTimestamps.contains(name))
 			_filesToDownload.push_back(file);
 		else {
+			localFileNotAvailableInCloud[name] = false;
+
 			if (_localFilesTimestamps[name] != INVALID_TIMESTAMP) {
 				if (_localFilesTimestamps[name] == file.timestamp())
 					continue;
@@ -115,11 +102,10 @@ void SavesSyncRequest::directoryListedCallback(Storage::ListDirectoryResponse pa
 		}
 	}
 
-	//upload files with invalid timestamp (the ones we've added - means they might not have any remote version)
+	//upload files which are unavailable in cloud
-	for (Common::HashMap<Common::String, uint32>::iterator i = _localFilesTimestamps.begin(); i != _localFilesTimestamps.end(); ++i) {
+	for (Common::HashMap<Common::String, bool>::iterator i = localFileNotAvailableInCloud.begin(); i != localFileNotAvailableInCloud.end(); ++i) {
 		if (i->_key == TIMESTAMPS_FILENAME) continue;
-		if (i->_value == INVALID_TIMESTAMP)
+		if (i->_value) _filesToUpload.push_back(i->_key);
-			_filesToUpload.push_back(i->_key);
 	}
 
 	///////
@@ -137,6 +123,50 @@ void SavesSyncRequest::directoryListedCallback(Storage::ListDirectoryResponse pa
 	downloadNextFile();
 }
 
+void SavesSyncRequest::directoryListedErrorCallback(Networking::ErrorResponse error) {
+	_workingRequest = nullptr;
+	if (_ignoreCallback) return;
+
+	bool irrecoverable = error.interrupted || error.failed;
+	if (error.failed) {
+		Common::JSONValue *value = Common::JSON::parse(error.response.c_str());
+		if (value) {
+			if (value->isObject()) {
+				Common::JSONObject object = value->asObject();
+
+				//Dropbox-related error:
+				if (object.contains("error_summary")) {
+					Common::String summary = object.getVal("error_summary")->asString();
+					if (summary.contains("not_found")) {						
+						irrecoverable = false;
+					}
+				}
+
+				//OneDrive-related error:
+				if (object.contains("error") && object.getVal("error")->isObject()) {
+					Common::JSONObject errorNode = object.getVal("error")->asObject();
+					if (errorNode.contains("code") && errorNode.contains("message")) {
+						Common::String code = errorNode.getVal("code")->asString();
+						if (code == "itemNotFound") {
+							irrecoverable = false;
+						}
+					}
+				}
+			}
+			delete value;
+		}
+	}
+
+	if (irrecoverable) {
+		finishError(error);
+		return;
+	}
+
+	//we're lucky - user just lacks his "/cloud/" folder
+	Common::Array<StorageFile> files;
+	directoryListedCallback(Storage::ListDirectoryResponse(error.request, files));
+}
+
 void SavesSyncRequest::downloadNextFile() {
 	if (_filesToDownload.empty()) {
 		uploadNextFile();
@@ -150,17 +180,18 @@ void SavesSyncRequest::downloadNextFile() {
 	debug("downloading %s", _currentDownloadingFile.name().c_str());
 	///////
 	_workingRequest = _storage->download(_currentDownloadingFile.path(), concatWithSavesPath(_currentDownloadingFile.name()),
-		new Common::Callback<SavesSyncRequest, Storage::BoolResponse>(this, &SavesSyncRequest::fileDownloadedCallback)
+		new Common::Callback<SavesSyncRequest, Storage::BoolResponse>(this, &SavesSyncRequest::fileDownloadedCallback),
+		new Common::Callback<SavesSyncRequest, Networking::ErrorResponse>(this, &SavesSyncRequest::fileDownloadedErrorCallback)
 	);
 }
 
-void SavesSyncRequest::fileDownloadedCallback(Storage::BoolResponse pair) {
+void SavesSyncRequest::fileDownloadedCallback(Storage::BoolResponse response) {
 	_workingRequest = nullptr;
 	if (_ignoreCallback) return;
 
 	//stop syncing if download failed
-	if (!pair.value) {
+	if (!response.value) {
-		finish();
+		finishError(Networking::ErrorResponse(this, false, true, "", -1));
 		return;
 	}
 
@@ -171,9 +202,17 @@ void SavesSyncRequest::fileDownloadedCallback(Storage::BoolResponse pair) {
 	downloadNextFile();
 }
 
+void SavesSyncRequest::fileDownloadedErrorCallback(Networking::ErrorResponse error) {
+	_workingRequest = nullptr;
+	if (_ignoreCallback) return;
+
+	//stop syncing if download failed
+	finishError(error);	
+}
+
 void SavesSyncRequest::uploadNextFile() {
 	if (_filesToUpload.empty()) {
-		finishBool(true);
+		finishSuccess(true);
 		return;
 	}
 
@@ -184,36 +223,45 @@ void SavesSyncRequest::uploadNextFile() {
 	debug("uploading %s", _currentUploadingFile.c_str());
 	///////
 	_workingRequest = _storage->upload("/saves/" + _currentUploadingFile, g_system->getSavefileManager()->openRawFile(_currentUploadingFile),
-		new Common::Callback<SavesSyncRequest, Storage::UploadResponse>(this, &SavesSyncRequest::fileUploadedCallback)
+		new Common::Callback<SavesSyncRequest, Storage::UploadResponse>(this, &SavesSyncRequest::fileUploadedCallback),
+		new Common::Callback<SavesSyncRequest, Networking::ErrorResponse>(this, &SavesSyncRequest::fileUploadedErrorCallback)
 	);
 }
 
-void SavesSyncRequest::fileUploadedCallback(Storage::UploadResponse pair) {
+void SavesSyncRequest::fileUploadedCallback(Storage::UploadResponse response) {
 	_workingRequest = nullptr;
 	if (_ignoreCallback) return;
-	UploadStatus status = pair.value;
-
-	//stop syncing if upload failed
-	if (status.interrupted || status.failed) {
-		finish();
-		return;
-	}
 	
 	//update local timestamp for the uploaded file
-	_localFilesTimestamps[_currentUploadingFile] = status.file.timestamp();
+	_localFilesTimestamps[_currentUploadingFile] = response.value.timestamp();
 
 	//continue uploading files
 	uploadNextFile();
 }
 
+void SavesSyncRequest::fileUploadedErrorCallback(Networking::ErrorResponse error) {
+	_workingRequest = nullptr;
+	if (_ignoreCallback) return;
+
+	//stop syncing if upload failed
+	finishError(error);
+}
+
 void SavesSyncRequest::handle() {}
 
 void SavesSyncRequest::restart() { start(); }
 
-void SavesSyncRequest::finish() { finishBool(false); }
+void SavesSyncRequest::finishError(Networking::ErrorResponse error) {
+	debug("SavesSync::finishError");
 
-void SavesSyncRequest::finishBool(bool success) {
+	//save updated timestamps (even if Request failed, there would be only valid timestamps)
-	Request::finish();
+	saveTimestamps();
+
+	Request::finishError(error);
+}
+
+void SavesSyncRequest::finishSuccess(bool success) {
+	Request::finishSuccess();
 
 	//save updated timestamps (even if Request failed, there would be only valid timestamps)
 	saveTimestamps();
@@ -234,7 +282,6 @@ void SavesSyncRequest::loadTimestamps() {
 		return;
 	}
 	
-	
 	while (!file->eos()) {
 		//read filename into buffer (reading until the first ' ')
 		Common::String buffer;

backends/cloud/savessyncrequest.h

@@ -45,22 +45,25 @@ class SavesSyncRequest: public Networking::Request {
 	bool _ignoreCallback;
 
 	void start();
-	void directoryListedCallback(Storage::ListDirectoryResponse pair);
+	void directoryListedCallback(Storage::ListDirectoryResponse response);
-	void fileDownloadedCallback(Storage::BoolResponse pair);
+	void directoryListedErrorCallback(Networking::ErrorResponse error);
-	void fileUploadedCallback(Storage::UploadResponse pair);
+	void fileDownloadedCallback(Storage::BoolResponse response);
+	void fileDownloadedErrorCallback(Networking::ErrorResponse error);
+	void fileUploadedCallback(Storage::UploadResponse response);
+	void fileUploadedErrorCallback(Networking::ErrorResponse error);
 	void downloadNextFile();
 	void uploadNextFile();
-	void finishBool(bool success);
+	virtual void finishError(Networking::ErrorResponse error);
+	void finishSuccess(bool success);
 	void loadTimestamps();
 	void saveTimestamps();
 	Common::String concatWithSavesPath(Common::String name);
 public:
-	SavesSyncRequest(Storage *storage, Storage::BoolCallback callback);
+	SavesSyncRequest(Storage *storage, Storage::BoolCallback callback, Networking::ErrorCallback ecb);
 	virtual ~SavesSyncRequest();
 
 	virtual void handle();
 	virtual void restart();	
-	virtual void finish();
 };
 
 } // End of namespace Cloud

backends/cloud/storage.h

@@ -34,53 +34,13 @@
 
 namespace Cloud {
 
-/** Struct to represent upload() resulting status. */
-struct UploadStatus {
-	/** true if Request was interrupted (finished by user with finish()) */
-	bool interrupted;
-	/** true if Request has failed (bad server response or some other error occurred) */
-	bool failed;
-	/** Contains uploaded file description (empty if failed) */
-	StorageFile file;
-	/** Server's original response (empty if not failed) */
-	Common::String response;
-	/** Server's HTTP response code. */
-	long httpResponseCode;
-
-	UploadStatus():
-		interrupted(false), failed(false), file(), response(), httpResponseCode(-1) {}
-
-	UploadStatus(bool interrupt, bool failure, StorageFile f, Common::String resp, long code):
-		interrupted(interrupt), failed(failure), file(f), response(resp), httpResponseCode(code) {}
-};
-
-/** Struct to represent upload() resulting status. */
-struct ListDirectoryStatus {
-	/** true if Request was interrupted (finished by user with finish()) */
-	bool interrupted;
-	/** true if Request has failed (bad server response or some other error occurred) */
-	bool failed;
-	/** Contains listed files (might be incomplete if failed or interrupted) */
-	Common::Array<StorageFile> &files;
-	/** Server's original response (empty if not failed) */
-	Common::String response;
-	/** Server's HTTP response code. */
-	long httpResponseCode;
-
-	ListDirectoryStatus(Common::Array<StorageFile> &f) :
-		interrupted(false), failed(false), files(f), response(), httpResponseCode(-1) {}
-
-	ListDirectoryStatus(bool interrupt, bool failure, Common::Array<StorageFile> &f, Common::String resp, long code) :
-		interrupted(interrupt), failed(failure), files(f), response(resp), httpResponseCode(code) {}
-};
-
 class Storage {
 public:
 	typedef Networking::Response<Common::Array<StorageFile>&> FileArrayResponse;
 	typedef Networking::Response<StorageInfo> StorageInfoResponse;
 	typedef Networking::Response<bool> BoolResponse;
-	typedef Networking::Response<UploadStatus> UploadResponse;
+	typedef Networking::Response<StorageFile> UploadResponse;
-	typedef Networking::Response<ListDirectoryStatus> ListDirectoryResponse;
+	typedef Networking::Response<Common::Array<StorageFile> &> ListDirectoryResponse;
 
 	typedef Common::BaseCallback<FileArrayResponse> *FileArrayCallback;
 	typedef Common::BaseCallback<StorageInfoResponse> *StorageInfoCallback;
@@ -113,35 +73,35 @@ public:
 	 */
 
 	/** Returns ListDirectoryStatus struct with list of files. */
-	virtual Networking::Request *listDirectory(Common::String path, ListDirectoryCallback callback, bool recursive = false) = 0;
+	virtual Networking::Request *listDirectory(Common::String path, ListDirectoryCallback callback, Networking::ErrorCallback errorCallback, bool recursive = false) = 0;
 	
 	/** Returns UploadStatus struct with info about uploaded file. */
-	virtual Networking::Request *upload(Common::String path, Common::SeekableReadStream *contents, UploadCallback callback) = 0;
+	virtual Networking::Request *upload(Common::String path, Common::SeekableReadStream *contents, UploadCallback callback, Networking::ErrorCallback errorCallback) = 0;
-	virtual Networking::Request *upload(Common::String remotePath, Common::String localPath, UploadCallback callback) = 0;
+	virtual Networking::Request *upload(Common::String remotePath, Common::String localPath, UploadCallback callback, Networking::ErrorCallback errorCallback) = 0;
 
 	/** Returns pointer to Networking::NetworkReadStream. */
-	virtual Networking::Request *streamFile(Common::String path, Networking::NetworkReadStreamCallback callback) = 0;
+	virtual Networking::Request *streamFile(Common::String path, Networking::NetworkReadStreamCallback callback, Networking::ErrorCallback errorCallback) = 0;
 
 	/** Calls the callback when finished. */
-	virtual Networking::Request *download(Common::String remotePath, Common::String localPath, BoolCallback callback) = 0;
+	virtual Networking::Request *download(Common::String remotePath, Common::String localPath, BoolCallback callback, Networking::ErrorCallback errorCallback) = 0;
 
 	/** Returns Common::Array<StorageFile> with list of files, which were not downloaded. */
-	virtual Networking::Request *downloadFolder(Common::String remotePath, Common::String localPath, FileArrayCallback callback, bool recursive = false) = 0;
+	virtual Networking::Request *downloadFolder(Common::String remotePath, Common::String localPath, FileArrayCallback callback, Networking::ErrorCallback errorCallback, bool recursive = false) = 0;
 
 	/** Calls the callback when finished. */
-	virtual Networking::Request *remove(Common::String path, BoolCallback callback) = 0;
+	virtual Networking::Request *remove(Common::String path, BoolCallback callback, Networking::ErrorCallback errorCallback) = 0;
 
 	/** Calls the callback when finished. */
-	virtual Networking::Request *syncSaves(BoolCallback callback) = 0;
+	virtual Networking::Request *syncSaves(BoolCallback callback, Networking::ErrorCallback errorCallback) = 0;
 
 	/** Calls the callback when finished. */
-	virtual Networking::Request *createDirectory(Common::String path, BoolCallback callback) = 0;
+	virtual Networking::Request *createDirectory(Common::String path, BoolCallback callback, Networking::ErrorCallback errorCallback) = 0;
 
 	/** Calls the callback when finished. */
-	virtual Networking::Request *touch(Common::String path, BoolCallback callback) = 0;
+	virtual Networking::Request *touch(Common::String path, BoolCallback callback, Networking::ErrorCallback errorCallback) = 0;
 
 	/** Returns the StorageInfo struct. */
-	virtual Networking::Request *info(StorageInfoCallback callback) = 0;
+	virtual Networking::Request *info(StorageInfoCallback callback, Networking::ErrorCallback errorCallback) = 0;
 
 	/** Returns whether saves sync process is running. */
 	virtual bool isSyncing() = 0;

backends/module.mk

@@ -40,7 +40,8 @@ MODULE_OBJS += \
 	networking/curl/connectionmanager.o \
 	networking/curl/networkreadstream.o \
 	networking/curl/curlrequest.o \
-	networking/curl/curljsonrequest.o
+	networking/curl/curljsonrequest.o \
+	networking/curl/request.o
 endif
 
 ifdef USE_ELF_LOADER

backends/networking/curl/curljsonrequest.cpp

@@ -31,8 +31,8 @@
 
 namespace Networking {
 
-CurlJsonRequest::CurlJsonRequest(JsonCallback cb, Common::String url):
+CurlJsonRequest::CurlJsonRequest(JsonCallback cb, ErrorCallback ecb, Common::String url):
-	CurlRequest(0, url), _jsonCallback(cb), _contentsStream(DisposeAfterUse::YES) {}
+	CurlRequest(nullptr, ecb, url), _jsonCallback(cb), _contentsStream(DisposeAfterUse::YES) {}
 
 CurlJsonRequest::~CurlJsonRequest() { delete _jsonCallback; }
 
@@ -66,33 +66,31 @@ void CurlJsonRequest::handle() {
 				warning("MemoryWriteStreamDynamic was unable to write all the bytes");
 
 		if (_stream->eos()) {
-			if (_stream->httpResponseCode() != 200)
-				warning("HTTP response code is not 200 OK (it's %ld)", _stream->httpResponseCode());
-
 			char *contents = getPreparedContents();
-			if (_stream->httpResponseCode() != 200)
-				debug("%s", contents);
 			Common::JSONValue *json = Common::JSON::parse(contents);
-			finishJson(json);
+			if (json) {
+				finishSuccess(json); //it's JSON even if's not 200 OK? That's fine!..
+			} else {
+				if (_stream->httpResponseCode() == 200) //no JSON, but 200 OK? That's fine!..
+					finishSuccess(nullptr);
+				else
+					finishError(ErrorResponse(this, false, true, contents, _stream->httpResponseCode()));
+			}
 		}
 	}
 }
 
 void CurlJsonRequest::restart() {
 	if (_stream) delete _stream;
-	_stream = 0;
+	_stream = nullptr;
 	_contentsStream = Common::MemoryWriteStreamDynamic(DisposeAfterUse::YES);
 	//with no stream available next handle() will create another one
 }
 
-void CurlJsonRequest::finishJson(Common::JSONValue *json) {
+void CurlJsonRequest::finishSuccess(Common::JSONValue *json) {
-	Request::finish();
+	Request::finishSuccess();
 	if (_jsonCallback) (*_jsonCallback)(JsonResponse(this, json)); //potential memory leak, free it in your callbacks!
 	else delete json;
 }
 
-void CurlJsonRequest::finish() {
-	finishJson(0);
-}
-
 } // End of namespace Networking

backends/networking/curl/curljsonrequest.h

@@ -41,15 +41,14 @@ protected:
 	char *getPreparedContents();
 
 	/** Sets FINISHED state and passes the JSONValue * into user's callback in JsonResponse. */
-	virtual void finishJson(Common::JSONValue *json);
+	virtual void finishSuccess(Common::JSONValue *json);
 
 public:
-	CurlJsonRequest(JsonCallback cb, Common::String url);
+	CurlJsonRequest(JsonCallback cb, ErrorCallback ecb, Common::String url);
 	virtual ~CurlJsonRequest();
 
 	virtual void handle(); 
 	virtual void restart();
-	virtual void finish();
 };
 
 } // End of namespace Networking

backends/networking/curl/curlrequest.cpp

@@ -30,8 +30,8 @@
 
 namespace Networking {
 
-CurlRequest::CurlRequest(DataCallback cb, Common::String url):
+CurlRequest::CurlRequest(DataCallback cb, ErrorCallback ecb, Common::String url):
-	Request(cb), _url(url), _stream(nullptr), _headersList(nullptr), _bytesBuffer(nullptr), _bytesBufferSize(0) {}
+	Request(cb, ecb), _url(url), _stream(nullptr), _headersList(nullptr), _bytesBuffer(nullptr), _bytesBufferSize(0) {}
 
 CurlRequest::~CurlRequest() {
 	delete _stream;
@@ -49,9 +49,14 @@ void CurlRequest::handle() {
 	if (!_stream) _stream = makeStream();	
 
 	if (_stream && _stream->eos()) {
-		if (_stream->httpResponseCode() != 200)
+		if (_stream->httpResponseCode() != 200) {
 			warning("HTTP response code is not 200 OK (it's %ld)", _stream->httpResponseCode());
-		finish();
+			ErrorResponse error(this, false, true, "", _stream->httpResponseCode());
+			finishError(error);
+			return;
+		}
+
+		finishSuccess(); //note that this Request doesn't call its callback on success (that's because it has nothing to return)
 	}
 }
 
@@ -101,4 +106,6 @@ NetworkReadStreamResponse CurlRequest::execute() {
 	return NetworkReadStreamResponse(this, _stream);
 }
 
+const NetworkReadStream *CurlRequest::getNetworkReadStream() const { return _stream; }
+
 } // End of namespace Networking

backends/networking/curl/curlrequest.h

@@ -48,7 +48,7 @@ protected:
 	virtual NetworkReadStream *makeStream();
 
 public:
-	CurlRequest(DataCallback cb, Common::String url);
+	CurlRequest(DataCallback cb, ErrorCallback ecb, Common::String url);
 	virtual ~CurlRequest();
 
 	virtual void handle();
@@ -73,7 +73,7 @@ public:
 	virtual NetworkReadStreamResponse execute();
 
 	/** Returns Request's NetworkReadStream. */
-	const NetworkReadStream *getNetworkReadStream() const { return _stream; }
+	const NetworkReadStream *getNetworkReadStream() const;
 };
 
 } // End of namespace Networking

backends/networking/curl/request.cpp

@@ -0,0 +1,70 @@
+/* ScummVM - Graphic Adventure Engine
+*
+* ScummVM is the legal property of its developers, whose names
+* are too numerous to list here. Please refer to the COPYRIGHT
+* file distributed with this source distribution.
+*
+* This program is free software; you can redistribute it and/or
+* modify it under the terms of the GNU General Public License
+* as published by the Free Software Foundation; either version 2
+* of the License, or (at your option) any later version.
+*
+* This program is distributed in the hope that it will be useful,
+* but WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+* GNU General Public License for more details.
+*
+* You should have received a copy of the GNU General Public License
+* along with this program; if not, write to the Free Software
+* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+*
+*/
+
+#include "backends/networking/curl/request.h"
+
+namespace Networking {
+
+ErrorResponse::ErrorResponse(Request *rq):
+	request(rq), interrupted(false), failed(true), response(""), httpResponseCode(-1) {}
+
+ErrorResponse::ErrorResponse(Request *rq, bool interrupt, bool failure, Common::String resp, long httpCode):
+	request(rq), interrupted(interrupt), failed(failure), response(resp), httpResponseCode(httpCode) {}
+
+Request::Request(DataCallback cb, ErrorCallback ecb):
+	_callback(cb), _errorCallback(ecb), _state(PROCESSING), _retryInSeconds(0) {}
+
+Request::~Request() {
+	delete _callback;
+	delete _errorCallback;
+}
+
+void Request::handleRetry() {
+	if (_retryInSeconds > 0) --_retryInSeconds;
+	else {
+		_state = PROCESSING;
+		restart();
+	}
+}
+
+void Request::pause() { _state = PAUSED; }
+
+void Request::finish() {
+	ErrorResponse error(this, true, false, "", -1);
+	finishError(error);
+}
+
+void Request::retry(uint32 seconds) {
+	_state = RETRY;
+	_retryInSeconds = seconds;
+}
+
+RequestState Request::state() const { return _state; }
+
+void Request::finishError(ErrorResponse error) {
+	_state = FINISHED;
+	if (_errorCallback) (*_errorCallback)(error);
+}
+
+void Request::finishSuccess() { _state = FINISHED; }
+
+} // End of namespace Networking

backends/networking/curl/request.h

@@ -25,6 +25,7 @@
 
 #include "common/callback.h"
 #include "common/scummsys.h"
+#include "common/str.h"
 
 namespace Networking {
 
@@ -51,8 +52,39 @@ template<typename T> struct Response {
 	Response(Request *rq, T v) : request(rq), value(v) {}
 };
 
+/**
+ * ErrorResponse is a struct to be returned from Request
+ * to user's failure callbacks.
+ *
+ * It keeps a Request pointer together with some useful
+ * information fields, which would explain why failure
+ * callback was called.
+ *
+ * <interrupted> flag is set when Request was interrupted,
+ * i.e. finished by user with finish() call.
+ *
+ * <failed> flag is set when Request has failed because of
+ * some error (bad server response, for example).
+ *
+ * <response> contains server's original response.
+ *
+ * <httpResponseCode> contains server's HTTP response code.
+ */
+
+struct ErrorResponse {
+	Request *request;
+	bool interrupted;
+	bool failed;
+	Common::String response;
+	long httpResponseCode;
+
+	ErrorResponse(Request *rq);
+	ErrorResponse(Request *rq, bool interrupt, bool failure, Common::String resp, long httpCode);
+};
+
 typedef Response<void *> DataReponse;
 typedef Common::BaseCallback<DataReponse> *DataCallback;
+typedef Common::BaseCallback<ErrorResponse> *ErrorCallback;
 
 /**
  * RequestState is used to indicate current Request state.
@@ -74,6 +106,9 @@ typedef Common::BaseCallback<DataReponse> *DataCallback;
  * After this state is set, but before ConnectionManager deletes the Request,
  * Request calls user's callback. User can ask Request to change its state
  * by calling retry() or pause() methods and Request won't be deleted.
+ *
+ * Request get a success and failure callbacks. Request must call one
+ * (and only one!) of these callbacks when it sets FINISHED state.
  */
 enum RequestState {
 	PROCESSING,
@@ -93,6 +128,13 @@ protected:
 	 */
 	DataCallback _callback;
 
+	/**
+	* Callback, which should be called when Request is failed/interrupted.
+	* That's the way Requests pass error information to the code which asked to create this request.
+	* @note callback must be called in finish() or similar method.
+	*/
+	ErrorCallback _errorCallback;
+
 	/**
 	 * Request state, which is used by ConnectionManager to determine
 	 * whether request might be deleted or it's still working.
@@ -106,45 +148,42 @@ protected:
 	/** In RETRY state this indicates whether it's time to call restart(). */
 	uint32 _retryInSeconds;
 
+	/** Sets FINISHED state and calls the _errorCallback with given error. */
+	virtual void finishError(ErrorResponse error);
+
+	/** Sets FINISHED state. Implementations might extend it if needed. */
+	virtual void finishSuccess();
+
 public:
-	Request(DataCallback cb): _callback(cb), _state(PROCESSING), _retryInSeconds(0) {}
+	Request(DataCallback cb, ErrorCallback ecb);
-	virtual ~Request() { delete _callback; }
+	virtual ~Request();
 
 	/** Method, which does actual work. Depends on what this Request is doing. */
 	virtual void handle() = 0;
 
 	/** Method, which is called by ConnectionManager when Request's state is RETRY.	 */
-	virtual void handleRetry() {
+	virtual void handleRetry();
-		if (_retryInSeconds > 0) --_retryInSeconds;
-		else {
-			_state = PROCESSING;
-			restart();
-		}
-	}
 
 	/** Method, which is used to restart the Request. */
 	virtual void restart() = 0;
 
 	/** Method, which is called to pause the Request. */
-	virtual void pause() { _state = PAUSED; }
+	virtual void pause();
 
 	/**
 	 * Method, which is called to *interrupt* the Request.
 	 * When it's called, Request must stop its work and
-	 * call the callback to notify user of failure.
+	 * call the failure callback to notify user.
 	 */
-	virtual void finish() { _state = FINISHED; }
+	virtual void finish();
 
 	/** Method, which is called to retry the Request. */
-	virtual void retry(uint32 seconds) {		
+	virtual void retry(uint32 seconds);
-		_state = RETRY;
-		_retryInSeconds = seconds;
-	}
 
 	/** Returns Request's current state. */
-	RequestState state() const { return _state; }
+	RequestState state() const;
 };
 
-} // End of namespace Cloud
+} // End of namespace Networking
 
 #endif

common/cloudmanager.h

@@ -64,7 +64,7 @@ public:
 	/**
 	 * Starts saves syncing process in currently active storage if there is any.
 	 */
-	virtual void syncSaves(Cloud::Storage::BoolCallback callback = 0) = 0;
+	virtual void syncSaves(Cloud::Storage::BoolCallback callback = nullptr, Networking::ErrorCallback errorCallback = nullptr) = 0;
 };
 
 } // End of namespace Common