js8call/JS8_UDP/NetworkMessage.cpp

/**
 * @file NetworkMessage.cpp
 * @brief Implementation of NetworkMessage::Builder and NetworkMessage::Reader
 * classes
 */

#include "NetworkMessage.h"
#include "JS8_Include/pimpl_impl.h"

#include <QByteArray>
#include <QDebug>
#include <QIODevice>
#include <QString>

#include <exception>

namespace NetworkMessage {
Builder::Builder(QIODevice *device, Type type, QString const &id,
                 quint32 schema)
    : QDataStream{device} {
    common_initialization(type, id, schema);
}

Builder::Builder(QByteArray *a, Type type, QString const &id, quint32 schema)
    : QDataStream{a, QIODevice::WriteOnly} {
    common_initialization(type, id, schema);
}

void Builder::common_initialization(Type type, QString const &id,
                                    quint32 schema) {
    if (schema <= 1) {
        setVersion(QDataStream::Qt_5_0); // Qt schema version
    }
    else if (schema <= 2) {
        setVersion(QDataStream::Qt_5_2); // Qt schema version
    }
    else if (schema <= 3) {
        setVersion(QDataStream::Qt_5_4); // Qt schema version
    }
    else {
        throw std::runtime_error{"Unrecognized message schema"};
    }

    // the following two items assume that the quint32 encoding is
    // unchanged over QDataStream versions
    *this << magic;
    *this << schema;

    *this << static_cast<quint32>(type) << id.toUtf8();
}

class Reader::impl {
  public:
    void common_initialization(Reader *parent) {
        quint32 magic;
        *parent >> magic;
        if (magic != Builder::magic) {
            throw std::runtime_error{"Invalid message format"};
        }
        *parent >> schema_;
        if (schema_ > Builder::schema_number) {
            throw std::runtime_error{"Unrecognized message schema"};
        }
        if (schema_ <= 1) {
            parent->setVersion(QDataStream::Qt_5_0);
        }
        else if (schema_ <= 2) {
            parent->setVersion(QDataStream::Qt_5_2);
        }
        else if (schema_ <= 3) {
            parent->setVersion(QDataStream::Qt_5_4);
        }
        quint32 type;
        *parent >> type >> id_;
        if (type >= maximum_message_type_) {
            qDebug() << "Unrecognized message type:" << type
                     << "from id:" << id_;
            type_ = maximum_message_type_;
        } else {
            type_ = static_cast<Type>(type);
        }
    }

    quint32 schema_;
    Type type_;
    QByteArray id_;
};

Reader::Reader(QIODevice *device) : QDataStream{device} {
    m_->common_initialization(this);
}

Reader::Reader(QByteArray const &a) : QDataStream{a} {
    m_->common_initialization(this);
}

Reader::~Reader() {}

quint32 Reader::schema() const { return m_->schema_; }

Type Reader::type() const { return static_cast<Type>(m_->type_); }

QString Reader::id() const { return QString::fromUtf8(m_->id_); }
} // namespace NetworkMessage