about push server message protocol, a forward-broker

[wsky]

first version https://github.com/wsky/top-push/commit/601db7b92061555141508dbddb8fcf6896b49283

    /*
     * 1byte MessageType, or extend to 8bit usage, 
     *      DUP Flag, 
     *      Body Formatter, 
     *      RETAIN
     * 
     * 8byte from(receiving)/to(sending) id, support front<-->forward<-->back.
     * 
     * 4byte remainingLength int32, do not need support longer message.
     * 
     * ...   body/content, maybe serialized by json/protobuf/msgpack/...
     * 
     * body example, just resolve/parse by client:
     * - publish message:
     *      { MessageId:"20121221000000001", Content:"hello world!" }       
     * - confirm message:
     *      ["20121221000000001", "20121221000000002"]
     */

    // server send: server -> client, write "from"
    // server receive: server <- client, read "to"

    // client send: client -> server, write "to"
    // client receive: client <- server, read "from"

MQTT is referred. http://public.dhe.ibm.com/software/dw/webservices/ws-mqtt/mqtt-v3r1.html

MessageType

https://github.com/wsky/top-push/blob/master/src/main/java/com/tmall/top/push/messages/MessageType.java

public class MessageType {
    // http://public.dhe.ibm.com/software/dw/webservices/ws-mqtt/mqtt-v3r1.html#msg-format
    // like MQTT
    // CONNECT,
    // CONNACK,
    // DISCONNECT,
    // SUBSCRIBE,
    // SUBACK,
    // UNSUBSCRIBE,
    // UNSUBACK,
    // PINGREQ,
    // PINGRESP,

    // publish message
    // publisher->server
    // server->subscriber
    public final static int PUBLISH = 1;
    // one pub, one acknowledge
    // public final static int PUBACK = 2;
    // PUBACK,
    // batch pub and batch confirm
    public final static int PUBCONFIRM = 2;
}

Message Base

https://github.com/wsky/top-push/blob/master/src/main/java/com/tmall/top/push/messages/Message.java

public abstract class Message {
    public int messageType;

    public int remainingLength;

    public String from;

    public String to;
}

[wsky]

about Message Body Formatter

JSON

string encoding:

• ascii
• [default] utf-8
• unicode

[wsky]

add full MQTT support

[wsky]

16

about mqtt support and abstract for it

[wsky]

MessageType is field of base protocl, just use by client

new protocol https://github.com/wsky/top-push/tree/master/src/main/protocol/

base protocol is forward protocol, but not routerable currently

/*
     * 1byte MessageType, or extend to 8bit usage, DUP Flag, Body Formatter,
     * RETAIN
     * 
     * 8byte from(receiving)/to(sending) id, support front<-->forward<-->back.
     * 
     * 1byte Message body format flag
     * 
     * 4byte remainingLength int32, do not need support longer message.
     * 
     * ... body/content, maybe serialized by json/protobuf/msgpack/...
     * 
     * body example, just resolve/parse by client: - publish message: {
     * MessageId:"20121221000000001", Content:"hello world!" } - confirm
     * message: ["20121221000000001", "20121221000000002"]
     */

    // server send: server -> client, write "from"
    // server receive: server <- client, read "to"

    // client send: client -> server, write "to"
    // client receive: client <- server, read "from"

base protocol via mqtt

/*
     * 
     * 1byte Fixed Header:
     * 
     * MessageType/DUP/QOS/RETAIN RETAIN
     * 
     * 1-4byte Remaining length, max 256 MB
     * 
     * 
     * PUBLISH
     * 
     * Variable Header: Topic Name/QoS level/Message ID
     * 
     * Payload:position=Fix-Header.length+Variable-Header.length
     * 
     * 1byte MessageType 8byte from(receiving)/to(sending) id, support
     * front<-->forward<-->back.
     * 
     * 
     * [X]PUBACK:
     * 
     * Variable Header: Message ID
     */

    // payload act forward(MessageIO)

    // server send: server -> client, write "from"
    // server receive: server <- client, read "to"

    // client send: client -> server, write "to"
    // client receive: client <- server, read "from"

publish-confirm just a special usage by client, like https://github.com/wsky/top-push-integration

[wsky]

8byte from(receiving)/to(sending) id, support front<-->forward<-->back.

8 is not fit,

->

1byte identity bytes count identity bytes

[wsky]

27