pomelo-upgrade/lib/connectors/mqtt/mqttadaptor.js

网易Pomelo升级版本

const Adaptor = function(opts)
{
    opts = opts || {};
    this.subReqs = {};
    this.publishRoute = opts.publishRoute;
    this.subscribeRoute = opts.subscribeRoute;
};

module.exports = Adaptor;

Adaptor.prototype.onPublish = function(client, packet)
{
    const route = this.publishRoute;

    if (!route)
    {
        throw new Error('unspecified publish route.');
    }

    let payload = packet.payload;
    if (payload instanceof Buffer)
    {
        payload = payload.toString('utf8');
    }

    const req = {
        id    : packet.messageId,
        route : route,
        body  : packet
    };

    client.emit('message', req);

    if (packet.qos === 1)
    {
        client.socket.puback({messageId: packet.messageId});
    }
};

Adaptor.prototype.onSubscribe = function(client, packet)
{
    const route = this.subscribeRoute;

    if (!route)
    {
        throw new Error('unspecified subscribe route.');
    }

    const req = {
        id    : packet.messageId,
        route : route,
        body  : {
            subscriptions : packet.subscriptions
        }
    };

    this.subReqs[packet.messageId] = packet;

    client.emit('message', req);
};

Adaptor.prototype.onPubAck = function(client, packet)
{
    const req = {
        id    : packet.messageId,
        route : 'connector.mqttHandler.pubAck',
        body  : {
            mid : packet.messageId
        }
    };

    this.subReqs[packet.messageId] = packet;

    client.emit('message', req);
};

/**
 * Publish message or subscription ack.
 *
 * if packet.id exist and this.subReqs[packet.id] exist then packet is a suback.
 * Subscription is request/response mode.
 * packet.id is pass from client in packet.messageId and record in Pomelo context and attached to the subscribe response packet.
 * packet.body is the context that returned by subscribe next callback.
 *
 * if packet.id not exist then packet is a publish message.
 *
 * otherwise packet is a illegal packet.
 */
Adaptor.prototype.publish = function(client, packet)
{
    const mid = packet.id;
    const subreq = this.subReqs[mid];
    if (subreq)
    {
        // is suback
        client.socket.suback({messageId : mid,
            granted   : packet.body});
        delete this.subReqs[mid];
        return;
    }

    client.socket.publish(packet.body);
};