diffusion/src/node_modules/features/topic-update.js

Diffusion JavaScript client

var _implements = require('util/interface')._implements;

var api = require('../../features/topic-update');
var logger = require('util/logger').create('diffusion.locks.TopicUpdate');

var Services = require('services/services');
var Emitter = require('events/emitter');
var Result = require('events/result');

var  Unconstrained = require('topic-update/update-constraint').Unconstrained;
var unconstrained = new Unconstrained();
var UpdateStreamFactory = require('topic-update/update-stream-factory');
var TopicType = require('../../topics/topics').TopicType;

var TopicUpdateImpl = _implements(
    api.TopicUpdate,
    function TopicUpdateImpl(internal) {
        var SET_TOPIC = internal.getServiceLocator().obtain(Services.SET_TOPIC);
        var ADD_AND_SET_TOPIC = internal.getServiceLocator().obtain(Services.ADD_AND_SET_TOPIC);

        var streamServices = {
            CREATE_UPDATE_STREAM: internal.getServiceLocator().obtain(Services.CREATE_UPDATE_STREAM),
            CREATE_UPDATE_STREAM_AND_SET: internal.getServiceLocator().obtain(Services.CREATE_UPDATE_STREAM_AND_SET),
            CHECK_UPDATE_STREAM: internal.getServiceLocator().obtain(Services.CHECK_UPDATE_STREAM),
            STREAM_SET_TOPIC_SERVICE: internal.getServiceLocator().obtain(Services.STREAM_SET_TOPIC_SERVICE),
            STREAM_APPLY_DELTA_SERVICE: internal.getServiceLocator().obtain(Services.STREAM_APPLY_DELTA_SERVICE),
            STREAM_ADD_TOPIC_SERVICE: internal.getServiceLocator().obtain(Services.STREAM_ADD_TOPIC_SERVICE),
            STREAM_ADD_AND_SET_TOPIC_SERVICE:
                internal.getServiceLocator().obtain(Services.STREAM_ADD_AND_SET_TOPIC_SERVICE)
        };

        var updateStreamFactory = new UpdateStreamFactory(streamServices);

        var setTopic = function(path, dataType, value, constraint) {
            var emitter = new Emitter();
            var result = new Result(emitter);

            SET_TOPIC.send({
                path: path,
                topicType: TopicType[dataType.name().toUpperCase()],
                value: dataType.from(value).asBuffer(),
                constraint: constraint
            },function(err, result) {
                if (err) {
                    logger.debug('Set topic failed');
                    emitter.error(err);
                }
                else {
                    emitter.emit('complete', result);
                }
            });

            return result;
        };

        var addAndSetTopic = function(path, specification, dataType, value, constraint) {
            var emitter = new Emitter();
            var result = new Result(emitter);

            if (specification.type !== TopicType[dataType.name().toUpperCase()]) {
                throw new Error("The specification and value have different data types");
            }

            ADD_AND_SET_TOPIC.send({
                path: path,
                topicSpecification: specification,
                value: dataType.from(value).asBuffer(),
                constraint: constraint
            },function(err, result) {
                if (err) {
                    logger.debug('Add and set topic failed');
                    emitter.error(err);
                }
                else {
                    emitter.emit('complete', result);
                }
            });

            return result;
        };


        this.set = function(path, dataType, value, options) {
            var constraint = (options!==undefined && options.constraint!==undefined)?options.constraint:unconstrained;
            if (options!==undefined && options.specification!==undefined) {
                return addAndSetTopic(path, options.specification, dataType, value, constraint);
            }
            else {
                return setTopic(path, dataType, value, constraint);
            }
        };

        this.createUpdateStream = function(path, dataType, options) {
            var constraint = (options!==undefined && options.constraint!==undefined)?options.constraint:unconstrained;
            if (options!==undefined && options.specification!==undefined) {
                return updateStreamFactory.createUpdateStreamThatAddsTopic(
                    path,
                    options.specification,
                    dataType,
                    constraint
                );
            }
            else {
                return updateStreamFactory.createUpdateStream(
                    path,
                    dataType,
                    (constraint !== undefined)?constraint:unconstrained
                );
            }
        };

    }
);

module.exports = TopicUpdateImpl;