diffusion/src/node_modules/topics/details/topic-details-serialiser.js

Diffusion JavaScript client

var Codec = require('io/codec');
var BEES = require('serialisers/byte-encoded-enum-serialiser');
var TopicType = require('../../../topics/topics').TopicType;

var TopicPropertiesSerialiser = require('./topic-properties-serialiser');
var RecordTopicDetailsSerialiser = require('./record-topic-details-serialiser');
var RoutingTopicDetailsSerialiser = require('./routing-topic-details-serialiser');
var SlaveTopicDetailsSerialiser = require('./slave-topic-details-serialiser');

function getSubSerialiser(type) {
    switch (type) {
        case TopicType.RECORD :
            return RecordTopicDetailsSerialiser;
        case TopicType.ROUTING :
            return RoutingTopicDetailsSerialiser;
        case TopicType.SLAVE :
            return SlaveTopicDetailsSerialiser;
    }

    return null;
}

/**
 * Serialise topic details - in practical terms this accepts a metadata instance
 * and writes necessary topic detail values around it.
 */
module.exports = {
    read : function(input) {
        var details = {};

        if (Codec.readBoolean(input)) {
            details.type = BEES.read(input, TopicType);

            if (Codec.readBoolean(input) === false) {
                return details;
            }

            details.schema = {};

            if (Codec.readBoolean(input) === false) {
                return details;
            }

            // auto subscribe (ignored)
            Codec.readBoolean(input);

            var tidyOnUnsubscribe = Codec.readBoolean(input);
            var reference = Codec.readString(input);

            var properties = TopicPropertiesSerialiser.read(input);

            var serialiser = getSubSerialiser(details.type);
            var attributes = {};

            if (serialiser) {
                attributes = serialiser.read(input);
            }

            attributes.tidyOnUnsubscribe = tidyOnUnsubscribe;
            attributes.properties = properties;
            attributes.reference = reference;

            details.attributes = attributes;
        }

        return details;
    },
    write : function(output, details) {
        if (details) {
            Codec.writeBoolean(output, true);
            BEES.write(output, details.type);

            // Schema
            Codec.writeBoolean(output, true);

            // Have attributes, write flag
            Codec.writeBoolean(output, true);

            // Auto subscribe (redundant)
            Codec.writeBoolean(output, true);

            // General attributes
            Codec.writeBoolean(output, details.attributes.tidyOnUnsubscribe);
            Codec.writeString(output, details.attributes.reference);

            TopicPropertiesSerialiser.write(output, details.attributes.properties);

            var serialiser = getSubSerialiser(details.type);

            if (serialiser) {
                serialiser.write(output, details.attributes);
            }
        } else {
            // No details
            Codec.writeBoolean(output, false);
        }
    }
};