NETWORKING: Enter SessionRequest

It is to be used in a Session, though it might be used separately. It
must implement keep-alive, but it does not yet.

You must not put it to ConnMan by yourself (instead, use start()) and
you must call close() after you've finished using this request.

You can either work with it in callback, or wait() and simply use its
methods (check it's success() and then, for example, use text()). Like
this:
```
Networking::SessionRequest *rq = new Networking::SessionRequest(url);
rq->startAndWait();
if (rq->success())
warning("HTTP GET: %s", rq->text());
rq->close();
```

2 files changed, 204 insertions, 0 deletions

diff --git a/backends/networking/curl/sessionrequest.cpp b/backends/networking/curl/sessionrequest.cpp
new file mode 100644
index 0000000000..5fe0e64aa1
--- /dev/null
+++ b/backends/networking/curl/sessionrequest.cpp
@@ -0,0 +1,135 @@
+/* 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.
+ *
+ */
+
+#define FORBIDDEN_SYMBOL_ALLOW_ALL
+
+#include <curl/curl.h>
+#include "backends/networking/curl/connectionmanager.h"
+#include "backends/networking/curl/networkreadstream.h"
+#include "backends/networking/curl/sessionrequest.h"
+#include "common/debug.h"
+#include "common/json.h"
+
+namespace Networking {
+
+SessionRequest::SessionRequest(Common::String url, DataCallback cb, ErrorCallback ecb):
+	CurlRequest(cb, ecb, url), _contentsStream(DisposeAfterUse::YES),
+	_buffer(new byte[CURL_SESSION_REQUEST_BUFFER_SIZE]), _text(nullptr),
+	_started(false), _complete(false), _success(false) {}
+
+SessionRequest::~SessionRequest() {
+	delete[] _buffer;
+}
+
+char *SessionRequest::getPreparedContents() {
+	//write one more byte in the end
+	byte zero[1] = {0};
+	_contentsStream.write(zero, 1);
+
+	//replace all "bad" bytes with '.' character
+	byte *result = _contentsStream.getData();
+	uint32 size = _contentsStream.size();
+
+	//make it zero-terminated string
+	result[size - 1] = '\0';
+
+	return (char *)result;
+}
+
+void SessionRequest::finishError(ErrorResponse error) {
+	_complete = true;
+	_success = false;
+	CurlRequest::finishError(error);
+}
+
+void SessionRequest::finishSuccess() {
+	_state = PAUSED;
+	_complete = true;
+	_success = true;
+
+	if (_callback)
+		(*_callback)(DataResponse(this, text()));
+}
+
+void SessionRequest::start() {
+	if (_started) {
+		warning("Can't start() SessionRequest as it is already started");
+	} else {
+		_started = true;
+		ConnMan.addRequest(this);
+	}
+}
+
+void SessionRequest::handle() {
+	if (!_stream) _stream = makeStream();
+
+	if (_stream) {
+		uint32 readBytes = _stream->read(_buffer, CURL_SESSION_REQUEST_BUFFER_SIZE);
+		if (readBytes != 0)
+			if (_contentsStream.write(_buffer, readBytes) != readBytes)
+				warning("SessionRequest: unable to write all the bytes into MemoryWriteStreamDynamic");
+
+		if (_stream->eos()) {			
+			finishSuccess();
+		}
+	}
+}
+
+void SessionRequest::restart() {
+	if (_stream)
+		delete _stream;
+	_stream = nullptr;
+	_contentsStream = Common::MemoryWriteStreamDynamic(DisposeAfterUse::YES);
+	_text = nullptr;
+	_complete = false;
+	_success = false;
+	//with no stream available next handle() will create another one
+}
+
+void SessionRequest::close() {
+	_state = FINISHED;
+}
+
+void SessionRequest::startAndWait() {
+	start();
+	wait();
+}
+
+bool SessionRequest::complete() {
+	return _complete;
+}
+
+bool SessionRequest::success() {
+	return _success;
+}
+
+char *SessionRequest::text() {
+	if (_text == nullptr)
+		_text = getPreparedContents();
+	return _text;
+}
+
+Common::JSONValue *SessionRequest::json() {
+	return Common::JSON::parse(text());
+}
+
+} // End of namespace Networking
diff --git a/backends/networking/curl/sessionrequest.h b/backends/networking/curl/sessionrequest.h
new file mode 100644
index 0000000000..590eee4a5a
--- /dev/null
+++ b/backends/networking/curl/sessionrequest.h
@@ -0,0 +1,69 @@
+/* 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.
+ *
+ */
+
+#ifndef BACKENDS_NETWORKING_CURL_SESSIONREQUEST_H
+#define BACKENDS_NETWORKING_CURL_SESSIONREQUEST_H
+
+#include "backends/networking/curl/curlrequest.h"
+#include "common/memstream.h"
+#include "common/json.h"
+
+namespace Networking {
+
+#define CURL_SESSION_REQUEST_BUFFER_SIZE 512 * 1024
+
+class SessionRequest: public CurlRequest {
+protected:
+	Common::MemoryWriteStreamDynamic _contentsStream;
+	byte *_buffer;
+	char *_text;
+	bool _started, _complete, _success;
+
+	/** Prepares raw bytes from _contentsStream. */
+	char *getPreparedContents();
+
+	virtual void finishError(ErrorResponse error);
+	virtual void finishSuccess();
+
+public:
+	SessionRequest(Common::String url, DataCallback cb = nullptr, ErrorCallback ecb = nullptr);
+	virtual ~SessionRequest();
+
+	virtual void start();
+	virtual void handle();
+	virtual void restart();
+
+	/** This request DOES NOT delete automatically after calling callbacks. It gets PAUSED, and in order to make it FINISHED (i.e. delete), this method MUST be called. */
+	virtual void close();
+
+	void startAndWait();
+
+	bool complete();
+	bool success();
+
+	char *text();
+	Common::JSONValue *json();
+};
+
+} // End of namespace Networking
+
+#endif