diffusion/src/node_modules/topic-update/new-update-stream.js

Diffusion JavaScript client

var _implements = require('util/interface')._implements;
var api = require('../../topic-update/update-stream');
var TopicCreationResult = require('../../topic-update/topic-update').TopicCreationResult;

var Emitter = require('events/emitter');
var Result = require('events/result');
var logger = require('util/logger').create('diffusion.locks.TopicUpdate');

var PendingSetStream = require('topic-update/pending-set-stream');
var PendingValidateStream = require('topic-update/pending-validate-stream');

var CreateUpdateStreamRequest = require('services/topic-update/create-update-stream-request');
var CreateUpdateStreamAndSetRequest = require('services/topic-update/create-update-stream-and-set-request');

var NewUpdateStream = _implements(
    api.UpdateStream,
    function NewUpdateStream(streamServices, options, stream, path, topicType, constraint) {

        this.set = function(value) {
            options.checkOperation(value);

            var emitter = new Emitter();
            var result = new Result(emitter);

            var buffer = options.dataType.from(value).asBuffer();
            stream.setDelegate(new PendingSetStream(streamServices, options, stream, result, value));
            streamServices.CREATE_UPDATE_STREAM_AND_SET.send(
                new CreateUpdateStreamAndSetRequest(path, topicType, buffer, constraint),
                function(err, streamId) {
                    if (err) {
                        logger.debug('Failed to create update stream and set');
                        stream.onSetFailed(err);
                        emitter.error(err);
                    }
                    else {
                        stream.onSetComplete(streamId);
                        emitter.emit('complete', TopicCreationResult.EXISTS);
                    }
                }
            );

            return result;
        };

        this.get = function() {
            throw new Error("The set method has not been called");
        };

        this.validate = function() {
            var emitter = new Emitter();
            var result = new Result(emitter);

            stream.setDelegate(new PendingValidateStream(streamServices, options, stream, result));
            streamServices.CREATE_UPDATE_STREAM.send(
                new CreateUpdateStreamRequest(path, topicType, constraint),
                function(err, result) {
                    if (err) {
                        logger.debug('Create update stream failed');
                        stream.onValidateFailed(err);
                        emitter.error(err);
                    }
                    else {
                        stream.onValidateComplete(result);
                        emitter.emit('complete', TopicCreationResult.EXISTS);
                    }
                }
            );

            return result;
        };

        this.onSetComplete = function() {
            throw new Error("No set request has been sent");
        };

        this.onSetFailed = function() {
            throw new Error("No set request has been sent");
        };

        this.onValidateComplete = function() {
            throw new Error("No validate request has been sent");
        };

        this.onValidateFailed = function() {
            throw new Error("No validate request has been sent");
        };
    }
);

module.exports = NewUpdateStream;