neovim-qt-0.2.16.1/src/msgpackiodevice.cpp

#include <QAbstractSocket>
#include <QTextCodec>
#include <QSocketNotifier>

// read/write
#ifdef _WIN32
# include <io.h>
# include "stdinreader.h"
#else
# include <unistd.h>
#endif

#include "msgpackiodevice.h"
#include "util.h"
#include "msgpackrequest.h"

namespace NeovimQt {

/**
 * \class NeovimQt::MsgpackIODevice
 *
 * \brief A msgpack-rpc channel build on top of QIODevice
 *
 */

/**
 * Build a MsgpackIODevice that reads from stdin and writes to
 * stdout
 */
MsgpackIODevice* MsgpackIODevice::fromStdinOut(QObject *parent)
{
	MsgpackIODevice *rpc = new MsgpackIODevice(NULL, parent);
	msgpack_packer_init(&rpc->m_pk, rpc, (msgpack_packer_write)MsgpackIODevice::msgpack_write_to_stdout);
#ifdef _WIN32
	StdinReader *rsn = new StdinReader(msgpack_unpacker_buffer_capacity(&rpc->m_uk), rpc);
	connect(rsn, &StdinReader::dataAvailable,
			rpc, &MsgpackIODevice::dataAvailableStdin);
	rsn->start();
#else
	QSocketNotifier *rsn = new QSocketNotifier(0, QSocketNotifier::Read, rpc);
	connect(rsn, &QSocketNotifier::activated,
			rpc, &MsgpackIODevice::dataAvailableFd);
#endif
	return rpc;
}

MsgpackIODevice::MsgpackIODevice(QIODevice *dev, QObject *parent)
:QObject(parent), m_reqid(0), m_dev(dev), m_encoding(0), m_reqHandler(0), m_error(NoError)
{
	qRegisterMetaType<MsgpackError>("MsgpackError");
	msgpack_unpacker_init(&m_uk, MSGPACK_UNPACKER_INIT_BUFFER_SIZE);

	if (m_dev) {
		// MSVC: wont build without the (mspack_packer_write) cast
		msgpack_packer_init(&m_pk, this, (msgpack_packer_write)MsgpackIODevice::msgpack_write_to_dev);

		m_dev->setParent(this);
		connect(m_dev, &QAbstractSocket::readyRead,
				this, &MsgpackIODevice::dataAvailable);

		if ( !m_dev->isSequential() ) {
			setError(InvalidDevice, tr("IO device needs to be sequential"));
			return;
		}
	}
}

MsgpackIODevice::~MsgpackIODevice()
{
	//msgpack_packer_destroy(&m_pk);
	msgpack_unpacker_destroy(&m_uk);
}

bool MsgpackIODevice::isOpen()
{
	if (m_error == InvalidDevice) {
		return false;
	} else if (m_dev) {
		return m_dev->isOpen();
	} else {
		return true;
	}
}

/** The encoding used by the MsgpackIODevice::encode and MsgpackIODevice::decode methods @see setEncoding */
QByteArray MsgpackIODevice::encoding() const
{
	if (m_encoding) {
		return m_encoding->name();
	}
	return QByteArray();
}

/**
 * Set encoding for strings in this RPC, if it not set we
 * fall back to utf8
 *
 * \see QTextCode
 */
bool MsgpackIODevice::setEncoding(const QByteArray& name)
{
	m_encoding = QTextCodec::codecForName(name);
	if (!m_encoding) {
		setError(UnsupportedEncoding, QString("Unsupported encoding (%1)").arg(QString::fromLatin1(name)));
		return false;
	}
	return true;
}

int MsgpackIODevice::msgpack_write_to_stdout(void* data, const char* buf, unsigned long int len)
{
	MsgpackIODevice *c = static_cast<MsgpackIODevice*>(data);
	qint64 bytes = write(1, buf, len);
	if (bytes == -1) {
		c->setError(InvalidDevice, tr("Error writing to device"));
	}
	return bytes;
}

int MsgpackIODevice::msgpack_write_to_dev(void* data, const char* buf, unsigned long int len)
{
	MsgpackIODevice *c = static_cast<MsgpackIODevice*>(data);
	qint64 bytes = c->m_dev->write(buf, len);
	if (bytes == -1) {
		c->setError(InvalidDevice, tr("Error writing to device"));
	}
	return bytes;
}

/**
 * Process incoming data.
 *
 * \see fromStdinOut() and StdinReader()
 */
void MsgpackIODevice::dataAvailableStdin(const QByteArray& data)
{
	if ( (quint64)data.length() > msgpack_unpacker_buffer_capacity(&m_uk)) {
		setError(InvalidDevice, tr("Error when reading from stdin, BUG(buffered data exceeds capaciy)"));
		return;
	} else if ( data.length() > 0 ) {
		memcpy(msgpack_unpacker_buffer(&m_uk), data.constData(), data.length());
		msgpack_unpacker_buffer_consumed(&m_uk, data.length());
		msgpack_unpacked result;
		msgpack_unpacked_init(&result);
		while(msgpack_unpacker_next(&m_uk, &result)) {
			dispatch(result.data);
		}
	}
}

/**
 * Process incoming data from the given fd.
 *
 * \see fromStdinOut() and QSocketNotifier()
 */
void MsgpackIODevice::dataAvailableFd(int fd)
{
	if ( msgpack_unpacker_buffer_capacity(&m_uk) == 0 ) {
		if ( !msgpack_unpacker_reserve_buffer(&m_uk, 8192 ) ) {
			qFatal("Could not allocate memory in unpack buffer");
			return;
		}
	}

	qint64 bytes = read(fd, msgpack_unpacker_buffer(&m_uk),
			msgpack_unpacker_buffer_capacity(&m_uk));
	if (bytes > 0) {
		msgpack_unpacker_buffer_consumed(&m_uk, bytes);
		msgpack_unpacked result;
		msgpack_unpacked_init(&result);
		while(msgpack_unpacker_next(&m_uk, &result)) {
			dispatch(result.data);
		}
	} else if (bytes == -1) {
		setError(InvalidDevice, tr("Error when reading from device"));
	}
}

/**
 * Process incoming data from the underlying device
 *
 * \see QIODevice()
 */
void MsgpackIODevice::dataAvailable()
{
	qint64 read = 1;
	while (read > 0) {
		if ( msgpack_unpacker_buffer_capacity(&m_uk) == 0 ) {
			if ( !msgpack_unpacker_reserve_buffer(&m_uk, 8192 ) ) {
				qFatal("Could not allocate memory in unpack buffer");
				return;
			}
		}

		read = m_dev->read(msgpack_unpacker_buffer(&m_uk), msgpack_unpacker_buffer_capacity(&m_uk));
		if ( read > 0 ) {
			msgpack_unpacker_buffer_consumed(&m_uk, read);
			msgpack_unpacked result;
			msgpack_unpacked_init(&result);
			while(msgpack_unpacker_next(&m_uk, &result)) {
				dispatch(result.data);
			}
		}
	}
}

/**
 * Send error response for the given request message
 */
void MsgpackIODevice::sendError(const msgpack_object& req, const QString& msg)
{
	if ( req.via.array.ptr[0].via.u64 != 0 ) {
		qFatal("Errors can only be send as replies to Requests(type=0)");
	}
	sendError(req.via.array.ptr[1].via.u64, msg);
}

void MsgpackIODevice::sendError(uint64_t msgid, const QString& msg)
{
	// [type(1), msgid, error, result(nil)]
	msgpack_pack_array(&m_pk, 4);
	msgpack_pack_int(&m_pk, 1); // 1 = Response
	msgpack_pack_int(&m_pk, msgid);
	QByteArray utf8 = msg.toUtf8();
	msgpack_pack_bin(&m_pk, utf8.size());
	msgpack_pack_bin_body(&m_pk, utf8.constData(), utf8.size());
	msgpack_pack_nil(&m_pk);
}

/**
 * Do some sanity checks and forward message to the proper handler
 */
void MsgpackIODevice::dispatch(msgpack_object& req)
{
	//
	// neovim msgpack rpc calls are
	// [type(int), msgid(int), method(int), args(array)]
	//

	if (req.type != MSGPACK_OBJECT_ARRAY) {
		qDebug() << "Received Invalid msgpack: not an array";
		return;
	}

	if (req.via.array.size < 3 || req.via.array.size > 4) {
		qDebug() << "Received Invalid msgpack: message len MUST be 3 or 4";
		return;
	}

	if (req.via.array.ptr[0].type != MSGPACK_OBJECT_POSITIVE_INTEGER) {
		qDebug() << "Received Invalid msgpack: msg type MUST be an integer";
		return;
	}
	uint64_t type = req.via.array.ptr[0].via.u64;

	switch(type) {
	case 0:
		if (req.via.array.ptr[1].type != MSGPACK_OBJECT_POSITIVE_INTEGER) {
			qDebug() << "Received Invalid request: msg id MUST be a positive integer";
			sendError(req, tr("Msg Id must be a positive integer"));
			return;
		}
		if (req.via.array.ptr[2].type != MSGPACK_OBJECT_BIN &&
				req.via.array.ptr[2].type != MSGPACK_OBJECT_STR) {
			qDebug() << "Received Invalid request: method MUST be a String" << req.via.array.ptr[2];
			sendError(req, tr("Method id must be a positive integer"));
			return;
		}
		if (req.via.array.ptr[3].type != MSGPACK_OBJECT_ARRAY) {
			qDebug() << "Invalid request: arguments MUST be an array";
			sendError(req, tr("Parameters must be an array"));
			return;
		}
		dispatchRequest(req);
		break;
	case 1:
		if (req.via.array.ptr[1].type != MSGPACK_OBJECT_POSITIVE_INTEGER) {
			qDebug() << "Received Invalid response: msg id MUST be a positive integer";
			return;
		}
		dispatchResponse(req);
		break;
	case 2:
		dispatchNotification(req);
		break;
	default:
		qDebug() << "Unsupported msg type" << type;
	}
}

/**
 * Handle request message
 *
 * [type(0), msgid(uint), method(bin), args([...])]
 */
void MsgpackIODevice::dispatchRequest(msgpack_object& req)
{
	uint64_t msgid = req.via.array.ptr[1].via.u64;
	QByteArray errmsg("Unknown method");
	QVariant params;
	QByteArray method;

	if (!m_reqHandler) {
		goto err;
	}

	if (decodeMsgpack(req.via.array.ptr[2], method)) {
		qDebug() << "Found unexpected method in request" << req;
		goto err;
	}
	if (decodeMsgpack(req.via.array.ptr[3], params)) {
		qDebug() << "Found unexpected parameters in request" << req;
		goto err;
	}
	m_reqHandler->handleRequest(this, msgid, method, params.toList());
	return;

err:
	// Send error reply [type(1), msgid, error, NIL]
	msgpack_pack_array(&m_pk, 4);
	msgpack_pack_int(&m_pk, 1);
	msgpack_pack_int(&m_pk, msgid);
	msgpack_pack_bin(&m_pk, errmsg.size());
	msgpack_pack_bin_body(&m_pk, errmsg.constData(), errmsg.size());
	msgpack_pack_nil(&m_pk);
}

/** Assign a handler for Msgpack-RPC requests */
void MsgpackIODevice::setRequestHandler(MsgpackRequestHandler *h)
{
	m_reqHandler = h;
}

/**
 * Send back a response [type(1), msgid(uint), error(...), result(...)]
 */
bool MsgpackIODevice::sendResponse(uint64_t msgid, const QVariant& err, const QVariant& res)
{
	if (!checkVariant(err) || !checkVariant(res)) {
		qDebug() << "Unable to serialize response" << res;
		sendError(msgid, tr("Internal server error, could not serialize response"));
		return false;
	}

	msgpack_pack_array(&m_pk, 4);
	msgpack_pack_int(&m_pk, 1);
	msgpack_pack_int(&m_pk, msgid);
	send(err);
	send(res);
	return true;
}

/**
 * Send [type(2), method, params]
 * Returns false if the params could not be serialized
 */
bool MsgpackIODevice::sendNotification(const QByteArray& method, const QVariantList& params)
{
	if (!checkVariant(params)) {
		return false;
	}

	msgpack_pack_array(&m_pk, 3);
	msgpack_pack_int(&m_pk, 2);
	send(method);
	send(params);
	return true;
}

/**
 * Handle response messages
 *
 * [type(1), msgid(uint), error(str?), result(...)]
 */
void MsgpackIODevice::dispatchResponse(msgpack_object& resp)
{
	// [type(1), msgid, error, result]
	uint64_t msgid = resp.via.array.ptr[1].via.u64;

	if ( !m_requests.contains(msgid) ) {
		qWarning() << "Received response for unknown message" << msgid;
		return;
	}

	MsgpackRequest *req = m_requests.take(msgid);
	if ( resp.via.array.ptr[2].type != MSGPACK_OBJECT_NIL ) {
		// Error response
		QVariant val;
		if (decodeMsgpack(resp.via.array.ptr[2], val)) {
			qWarning() << "Error decoding response error object";
			goto err;
		}
		emit req->error(req->id, req->function(), val);
	} else {
		QVariant val;
		if (decodeMsgpack(resp.via.array.ptr[3], val)) {
			qWarning() << "Error decoding response object";
			goto err;
		}
		emit req->finished(req->id, req->function(), val);
	}
err:
	req->deleteLater();
}

/** Return list of pending request ids */
QList<quint32> MsgpackIODevice::pendingRequests() const
{
	return m_requests.keys();
}

/**
 * [type(2), method, params]
 *
 */
void MsgpackIODevice::dispatchNotification(msgpack_object& nt)
{
	QByteArray methodName;
	if (decodeMsgpack(nt.via.array.ptr[1], methodName)) {
		qDebug() << "Received Invalid notification: event MUST be a String";
		return;
	}

	QVariant val;
	if (decodeMsgpack(nt.via.array.ptr[2], val) ||
			(QMetaType::Type)val.type() != QMetaType::QVariantList  ) {
		qDebug() << "Unable to unpack notification parameters" << nt;
		return;
	}
	emit notification(methodName, val.toList());
}

/**
 * Sets latest error code and message for this connector
 */
void MsgpackIODevice::setError(MsgpackError err, const QString& msg)
{
	m_error = err;
	m_errorString = msg;
	qWarning() << "MsgpackIO fatal error" << m_errorString;
	emit error(m_error);
}

/** Return error string for the current error */
QString MsgpackIODevice::errorString() const
{
	if (m_error) {
		return m_errorString;
	} else if (m_dev) {
		return m_dev->errorString();
	} else {
		return QString();
	}
}

/**
 * Start an RPC request
 *
 * Use send() to pass on each of the call parameters
 *
 * Returns a MsgpackRequest object. You can connect to
 * its finished() SIGNAL to handle the response
 */
MsgpackRequest* MsgpackIODevice::startRequestUnchecked(const QString& method, quint32 argcount)
{
	quint32 msgid = msgId();
	// [type(0), msgid, method, args]
	msgpack_pack_array(&m_pk, 4);
	msgpack_pack_int(&m_pk, 0);
	msgpack_pack_int(&m_pk, msgid);
	const QByteArray& utf8 = method.toUtf8();
	msgpack_pack_bin(&m_pk, utf8.size());
	msgpack_pack_bin_body(&m_pk, utf8.constData(), utf8.size());
	msgpack_pack_array(&m_pk, argcount);

	MsgpackRequest *r = new MsgpackRequest( msgid, this);
	connect(r, &MsgpackRequest::timeout,
			this, &MsgpackIODevice::requestTimeout);
	m_requests.insert(msgid, r);
	return r;
}

/**
 * Request timed out, discard it
 */
void MsgpackIODevice::requestTimeout(quint32 id)
{
	if (m_requests.contains(id)) {
		MsgpackRequest *r = m_requests.take(id);
		r->deleteLater();
		qWarning() << "Request" << id << "timed out:"  << r->function();
	}
}

/**
 * Returns a new msgid that can be used for a msg
 */
quint32 MsgpackIODevice::msgId()
{
	return this->m_reqid++;
}

void MsgpackIODevice::send(int64_t i)
{
	msgpack_pack_int64(&m_pk, i);
}
bool MsgpackIODevice::decodeMsgpack(const msgpack_object& in, int64_t& out)
{
	if ( in.type != MSGPACK_OBJECT_POSITIVE_INTEGER) {
		qWarning() << "Attempting to decode as int64_t when type is" << in.type << in;
		out = -1;
		return true;
	}
	out = in.via.i64;
	return false;
}

void MsgpackIODevice::send(double d)
{
	msgpack_pack_float(&m_pk, d);
}
bool MsgpackIODevice::decodeMsgpack(const msgpack_object& in, double& out)
{
	if ( in.type != MSGPACK_OBJECT_FLOAT) {
		qWarning() << "Attempting to decode as double when type is" << in.type << in;
		out = -1;
		return true;
	}
	out = in.via.f64;
	return false;
}

/**
 * Serialise a value into the msgpack stream
 */
void MsgpackIODevice::send(const QByteArray& bin)
{
	msgpack_pack_bin(&m_pk, bin.size());
	msgpack_pack_bin_body(&m_pk, bin.constData(), bin.size());
}
bool MsgpackIODevice::decodeMsgpack(const msgpack_object& in, QByteArray& out)
{
	if ( in.type == MSGPACK_OBJECT_BIN) {
		out = QByteArray(in.via.bin.ptr, in.via.bin.size);
	} else if ( in.type == MSGPACK_OBJECT_STR) {
		out = QByteArray(in.via.str.ptr, in.via.str.size);
	} else {
		qWarning() << "Attempting to decode as QByteArray when type is" << in.type << in;
		out = QByteArray();
		return true;
	}
	return false;
}


/**
 * Serialise a valud into the msgpack stream
 */
void MsgpackIODevice::send(bool b)
{
	if ( b ) {
		msgpack_pack_true(&m_pk);
	} else {
		msgpack_pack_false(&m_pk);
	}
}
bool MsgpackIODevice::decodeMsgpack(const msgpack_object& in, bool& out)
{
	if ( in.type != MSGPACK_OBJECT_BOOLEAN) {
		qWarning() << "Attempting to decode as bool when type is" << in.type << in;
		out = false;
		return true;
	}
	out = in.via.boolean;
	return false;
}


void MsgpackIODevice::send(const QList<QByteArray>& list)
{
	msgpack_pack_array(&m_pk, list.size());
	foreach(const QByteArray& elem, list) {
		send(elem);
	}
}
bool MsgpackIODevice::decodeMsgpack(const msgpack_object& in, QList<QByteArray>& out)
{
	out.clear();
	if ( in.type != MSGPACK_OBJECT_ARRAY) {
		qWarning() << "Attempting to decode as QList<QByteArray> when type is" << in.type << in;
		return true;
	}

	for (uint64_t i=0; i<in.via.array.size; i++) {
		QByteArray val;
		if (decodeMsgpack(in.via.array.ptr[i], val)) {
			out.clear();
			return true;
		}
		out.append(val);
	}
	return false;
}

bool MsgpackIODevice::decodeMsgpack(const msgpack_object& in, QList<int64_t>& out)
{
	out.clear();
	if ( in.type != MSGPACK_OBJECT_ARRAY) {
		qWarning() << "Attempting to decode as QList<int64_t> when type is" << in.type << in;
		return true;
	}

	for (uint64_t i=0; i<in.via.array.size; i++) {
		int64_t val;
		if (decodeMsgpack(in.via.array.ptr[i], val)) {
			out.clear();
			return true;
		}
		out.append(val);
	}
	return false;
}

bool MsgpackIODevice::decodeMsgpack(const msgpack_object& in, QList<double>& out)
{
	out.clear();
	if ( in.type != MSGPACK_OBJECT_ARRAY) {
		qWarning() << "Attempting to decode as QList<double> when type is" << in.type << in;
		return true;
	}

	for (uint64_t i=0; i<in.via.array.size; i++) {
		double val;
		if (decodeMsgpack(in.via.array.ptr[i], val)) {
			out.clear();
			return true;
		}
		out.append(val);
	}
	return false;
}

/**
 * We use QVariants for RPC functions that use the *Object* type do not use
 * this in any other conditions
 */
bool MsgpackIODevice::decodeMsgpack(const msgpack_object& in, QVariant& out)
{
	switch (in.type) {
	case MSGPACK_OBJECT_NIL:
		out = QVariant();
		break;
	case MSGPACK_OBJECT_BOOLEAN:
		out = in.via.boolean;
		break;
	case MSGPACK_OBJECT_NEGATIVE_INTEGER:
		out = QVariant((qint64)in.via.i64);
		break;
	case MSGPACK_OBJECT_POSITIVE_INTEGER:
		out = QVariant((quint64)in.via.u64);
		break;
	case MSGPACK_OBJECT_FLOAT:
		out = in.via.f64;
		break;
	case MSGPACK_OBJECT_STR:
	case MSGPACK_OBJECT_BIN:
		{
		QByteArray val;
		if (decodeMsgpack(in, val)) {
			qWarning() << "Error unpacking ByteArray as QVariant";
			out = QVariant();
			return true;
		}
		out = val;
		}
		break;
	case MSGPACK_OBJECT_ARRAY:
		// Either a QVariantList or a QStringList
		{
		QVariantList ls;
		for (uint64_t i=0; i<in.via.array.size; i++) {
			QVariant v;
			bool failed = decodeMsgpack(in.via.array.ptr[i], v);
			if (failed) {
				qWarning() << "Error unpacking Map as QVariantList";
				out = QVariant();
				return true;
			}
			ls.append(v);
		}
		out = ls;
		}
		break;
	case MSGPACK_OBJECT_MAP:
		{
		QVariantMap m;
		for (uint64_t i=0; i<in.via.map.size; i++) {
			QByteArray key;
			if (decodeMsgpack(in.via.map.ptr[i].key, key)) {
				qWarning() << "Error decoding Object(Map) key";
				out = QVariant();
				return true;
			}
			QVariant val;
			if (decodeMsgpack(in.via.map.ptr[i].val, val)) {
				qWarning() << "Error decoding Object(Map) value";
				out = QVariant();
				return true;
			}
			m.insert(key,val);
		}
		out = m;
		}
		break;
	case MSGPACK_OBJECT_EXT:
		if (m_extTypes.contains(in.via.ext.type)) {
			out = m_extTypes.value(in.via.ext.type)(this, in.via.ext.ptr, in.via.ext.size);
			if (!out.isValid()) {
				qWarning() << "EXT unpacking failed" << in.via.ext.type;
				return true;
			}
		} else {
			out = QVariant();
			qWarning() << "Unsupported EXT type found in Object" << in.via.ext.type;
		}
		break;
	default:
		out = QVariant();
		qWarning() << "Unsupported type found in Object" << in.type << in;
		return true;
	}
	return false;
}

/**
 * Register a function to decode Msgpack EXT types
 *
 * @see msgpackExtDecoder
 */
void MsgpackIODevice::registerExtType(int8_t type, msgpackExtDecoder fun)
{
	m_extTypes.insert(type, fun);
}

/**
 * Serialise a value into the msgpack stream
 *
 * We use QVariants for RPC functions that use the *Object* type. Do not use
 * this in any other conditions
 */
void MsgpackIODevice::send(const QVariant& var)
{
	if (!checkVariant(var)) {
		msgpack_pack_nil(&m_pk);
		qWarning() << "Trying to pack unsupported variant type" << var.type() << "packing Nil instead";
		return;
	}

	switch((QMetaType::Type)var.type()) {
	case QMetaType::Void:
	case QMetaType::UnknownType:
		msgpack_pack_nil(&m_pk);
		break;
	case QMetaType::Bool:
		send(var.toBool());
		break;
	case QMetaType::Int:
		msgpack_pack_int(&m_pk, var.toInt());
		break;
	case QMetaType::UInt:
		msgpack_pack_unsigned_int(&m_pk, var.toUInt());
		break;
	case QMetaType::Long:
		msgpack_pack_long_long(&m_pk, var.toLongLong());
		break;
	case QMetaType::LongLong:
		msgpack_pack_long_long(&m_pk, var.toLongLong());
		break;
	case QMetaType::ULong:
		msgpack_pack_unsigned_long_long(&m_pk, var.toULongLong());
		break;
	case QMetaType::ULongLong:
		msgpack_pack_unsigned_long_long(&m_pk, var.toULongLong());
		break;
	case QMetaType::Float:
		msgpack_pack_float(&m_pk, var.toFloat());
		break;
	case QMetaType::Double:
		msgpack_pack_double(&m_pk, var.toDouble());
		break;
	case QMetaType::QByteArray:
		send(var.toByteArray());
		break;
	case QMetaType::QStringList:
		msgpack_pack_array(&m_pk, var.toList().size());
		foreach(const QVariant& elem, var.toList()) {
			send(elem);
		}
		break;
	case QMetaType::QVariantList:
		msgpack_pack_array(&m_pk, var.toList().size());
		foreach(const QVariant& elem, var.toList()) {
			send(elem);
		}
		break;
	case QMetaType::QVariantMap:
		{
		const QVariantMap& m = var.toMap();
		msgpack_pack_map(&m_pk, m.size());
		QMapIterator<QString,QVariant> it(m);
		while(it.hasNext()) {
			it.next();
			send(it.key());
			send(it.value());
		}
		}
		break;
	case QMetaType::QPoint:
		// As an array [row, col]
		msgpack_pack_array(&m_pk, 2);
		msgpack_pack_int64(&m_pk, var.toPoint().y());
		msgpack_pack_int64(&m_pk, var.toPoint().x());
		break;
	case QMetaType::QString:
		send(encode(var.toString()));
		break;
	default:
		msgpack_pack_nil(&m_pk);
		qWarning() << "There is a BUG in the QVariant serializer" << var.type();
	}
}

bool MsgpackIODevice::decodeMsgpack(const msgpack_object& in, QPoint& out)
{
	if ( in.type != MSGPACK_OBJECT_ARRAY || in.via.array.size != 2 ) {
		goto fail;
	}
	int64_t col, row;
	if (decodeMsgpack(in.via.array.ptr[0], row)) {
		goto fail;
	}
	if (decodeMsgpack(in.via.array.ptr[1], col)) {
		goto fail;
	}

	// QPoint is (x,y)  neovim Position is (row, col)
	out = QPoint(col, row);
	return false;

fail:
	qWarning() << "Attempting to decode as QPoint failed" << in.type << in;
	out =  QPoint();
	return true;
}

/**
 * Convert string to the proper encoding
 * \see MsgpackIODevice::setEncoding
 */
QByteArray MsgpackIODevice::encode(const QString& str)
{
	if (m_encoding) {
		return m_encoding->fromUnicode(str);
	} else {
		qWarning() << "Encoding String into MsgpackIODevice without an encoding (defaulting to utf8)";
		return str.toUtf8();
	}
}

/**
 * Decode byte array as string, from Neovim's encoding
 */
QString MsgpackIODevice::decode(const QByteArray& data)
{
	if (m_encoding) {
		return m_encoding->toUnicode(data);
	} else {
		qWarning() << "Decoding String from MsgpackIODevice without an encoding (defaulting to utf8)";
		return QString::fromUtf8(data);
	}
}

/**
 * QVariant can encapsulate some data types that cannot be serialised at as
 * msgpack data..
 *
 * Ideally we would detect such errors early on and avoid sending those objects
 * entirely - this function checks if QVariant objects are admissible
 *
 * Returns true if the QVariant can be serialized
 */
bool MsgpackIODevice::checkVariant(const QVariant& var)
{
	switch((QMetaType::Type)var.type()) {
	case QMetaType::UnknownType:
		break;
	case QMetaType::Bool:
		break;
	case QMetaType::Int:
		break;
	case QMetaType::UInt:
		break;
	case QMetaType::Long:
		break;
	case QMetaType::LongLong:
		break;
	case QMetaType::ULong:
		break;
	case QMetaType::ULongLong:
		break;
	case QMetaType::Float:
		break;
	case QMetaType::QString:
		break;
	case QMetaType::Double:
		break;
	case QMetaType::QByteArray:
		break;
	case QMetaType::QStringList:
		break;
	case QMetaType::QVariantList:
		foreach(const QVariant& elem, var.toList()) {
			if (!checkVariant(elem)) {
				return false;
			}
		}
		break;
	case QMetaType::QVariantMap:
		{
		const QVariantMap& m = var.toMap();
		QMapIterator<QString,QVariant> it(m);
		while(it.hasNext()) {
			it.next();
			if (!checkVariant(it.key())) {
				return false;
			}
			if (!checkVariant(it.value())) {
				return false;
			}
		}
		}
		break;
	case QMetaType::QPoint:
		break;
	default:
		return false;
	}
	return true;
}

} // Namespace NeovimQt