diffusion/src/node_modules/topic-update/set-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 InvalidSetStream = require('topic-update/invalid-set-stream');

var UpdateStreamRequest = require('services/topic-update/update-stream-request');

var SetStream = _implements(
    api.UpdateStream,
    function SetStream(streamServices, options, stream, streamId, value) {
        var cache = value;

        this.set = function(value) {
            options.checkOperation(value);
            var emitter = new Emitter();
            var result = new Result(emitter);

            var buffer = options.toBuffer(cache, value);
            cache = value;
            options.deltaService.send(
                new UpdateStreamRequest(streamId, buffer),
                function(err, streamId) {
                    if (err) {
                        logger.debug('Set update stream failed');
                        stream.onSetFailed(err);
                        emitter.error(err);
                    }
                    else {
                        stream.onSetComplete(streamId);
                        emitter.emit('complete', TopicCreationResult.EXISTS);
                    }
                }
            );

            return result;
        };

        this.get = function() {
            return cache;
        };

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

            streamServices.CHECK_UPDATE_STREAM.send(streamId,
                function(err, result) {
                    if (err) {
                        logger.debug('Validate update stream failed');
                        stream.onValidateFailed(err);
                        emitter.error(err);
                    }
                    else {
                        stream.onValidateComplete(result);
                        emitter.emit('complete', TopicCreationResult.EXISTS);
                    }
                }
            );

            return result;
        };

        this.onSetComplete = function() {
        };

        this.onSetFailed = function(err) {
            stream.setDelegate(new InvalidSetStream(err, cache));
        };

        this.onValidateComplete = function() {
        };

        this.onValidateFailed = function(err) {
            stream.setDelegate(new InvalidSetStream(err, cache));
        };
    }
);

module.exports = SetStream;