qmqtt_frame.h

/*
 * qmqtt_frame.h - qmqtt frame heaer
 *
 * Copyright (c) 2013  Ery Lee <ery.lee at gmail dot com>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *   * Redistributions of source code must retain the above copyright notice,
 *     this list of conditions and the following disclaimer.
 *   * Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *   * Neither the name of mqttc nor the names of its contributors may be used
 *     to endorse or promote products derived from this software without
 *     specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 */
#ifndef QMQTT_FRAME_H
#define QMQTT_FRAME_H

#include <QObject>

#define PROTOCOL_MAGIC "MQIsdp"

#define CONNECT 0x10
#define CONNACK 0x20
#define PUBLISH 0x30
#define PUBACK 0x40
#define PUBREC 0x50
#define PUBREL 0x60
#define PUBCOMP 0x70
#define SUBSCRIBE 0x80
#define SUBACK 0x90
#define UNSUBSCRIBE 0xA0
#define UNSUBACK 0xB0
#define PINGREQ 0xC0
#define PINGRESP 0xD0
#define DISCONNECT 0xE0

#define LSB(A) (quint8)(A & 0x00FF)
#define MSB(A) (quint8)((A & 0xFF00) >> 8)

/*
|--------------------------------------
| 7 6 5 4 |     3    |  2 1  | 0      |
|  Type   | DUP flag |  QoS  | RETAIN |
|--------------------------------------
*/
#define GETTYPE(HDR)		(HDR & 0xF0)
#define SETQOS(HDR, Q)		(HDR | ((Q) << 1))
#define GETQOS(HDR)			((HDR & 0x06) >> 1)
#define SETDUP(HDR, D)		(HDR | ((D) << 3))
#define GETDUP(HDR)			((HDR & 0x08) >> 3)
#define SETRETAIN(HDR, R)	(HDR | (R))
#define GETRETAIN(HDR)		(HDR & 0x01)

/*
|----------------------------------------------------------------------------------
|     7    |    6     |      5     |  4   3  |     2    |       1      |     0    |
| username | password | willretain | willqos | willflag | cleansession | reserved |
|----------------------------------------------------------------------------------
*/
#define FLAG_CLEANSESS(F, C)	(F | ((C) << 1))
#define FLAG_WILL(F, W)			(F | ((W) << 2))
#define FLAG_WILLQOS(F, Q)		(F | ((Q) << 3))
#define FLAG_WILLRETAIN(F, R) 	(F | ((R) << 5))
#define FLAG_PASSWD(F, P)		(F | ((P) << 6))
#define FLAG_USERNAME(F, U)		(F | ((U) << 7))

namespace QMQTT {

class Frame : public QObject
{
    Q_OBJECT

    Q_DISABLE_COPY(Frame)

public:
    explicit Frame(quint8 header, QObject *parent = 0);
    explicit Frame(quint8 header, QByteArray & data, QObject *parent = 0);
    ~Frame();

    quint8 header();
    QByteArray & data();

    int readInt();
    char readChar();
    QString readString();

    void writeInt(int i);
    void writeChar(char c);
    void writeString(const QString &string);
    void writeRawData(const QByteArray &data);

    //TODO: FIXME LATER
    void write(QDataStream &stream);

private:
    void encodeLength(QByteArray & lenbuf, int length);
    quint8 _header;
    QByteArray _data;
};

} // namespace QMQTT

#endif // QMQTT_FRAME_H