joynr.messaging.channel.LongPollingChannelMessageReceiver.js Maven / Gradle / Ivy
/*jslint es5: true */
/*
* #%L
* %%
* Copyright (C) 2011 - 2015 BMW Car IT GmbH
* %%
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
* #L%
*/
define(
"joynr/messaging/channel/LongPollingChannelMessageReceiver",
[
"global/Promise",
"uuid",
"joynr/messaging/JoynrMessage",
"JsonParser",
"joynr/messaging/MessagingQos",
"joynr/system/DiagnosticTags",
"joynr/system/LoggerFactory",
"joynr/util/UtilInternal",
"joynr/util/LongTimer"
],
function(
Promise,
uuid,
JoynrMessage,
JsonParser,
MessagingQos,
DiagnosticTags,
LoggerFactory,
Util,
LongTimer) {
/**
* LongPollingChannelMessageReceiver handles the long poll to the bounce proxy.
*
* @name LongPollingChannelMessageReceiver
* @constructor
*
* @param {Object}
* settings an object containing required input for LongPollingChannelMessageReceiver
* @param {String}
* settings.bounceProxyUrl an object describing the bounce proxy URL
* @param {CommunicationModule}
* settings.communicationModule the API required by the LongPollingChannelMessageReceiver to perform XMLHTTPRequests
* socket communication
* @param {Object}
* settings.channelQos parameters specifying the qos requirements for the channel (creation)
* @param {Number}
* settings.channelQos.creationTimeout_ms max time to create a channel
* @param {Number}
* settings.channelQos.creationRetryDelay_ms retry interval after a failing channel creation
*
* @returns the LongPollingChannelMessageReceiver
*/
function LongPollingChannelMessageReceiver(settings) {
var storagePrefix = "joynr.channels";
var persistency = settings.persistency;
var onReceive;
var channelOpMessagingQos = new MessagingQos();
var channelId, channelUrl;
var communicationModule = settings.communicationModule;
var log = LoggerFactory.getLogger("joynr.messaging.LongPollingChannelMessageReceiver");
var bounceProxyChannelBaseUrl = settings.bounceProxyUrl + "channels/";
var channelCreationTimeout_ms = settings.channelQos && settings.channelQos.creationTimeout_ms ? settings.channelQos.creationTimeout_ms : 1000*60*60*24; // default: 1 day
var channelCreationRetryDelay_ms = settings.channelQos && settings.channelQos.creationRetryDelay_ms ? settings.channelQos.creationRetryDelay_ms : 1000*30; // default: 30s
var createChannelTimestamp;
/**
* Retrieve the receiverId for the given channelId
*
* @name LongPollingChannelMessageReceiver#getReceiverId
* @function
* @private
*/
function getReceiverId(channelId) {
var receiverId =
persistency.getItem(storagePrefix + "." + channelId + ".receiverId");
if (receiverId === undefined || receiverId === null) {
receiverId = "tid-" + uuid();
persistency.setItem(
storagePrefix + "." + channelId + ".receiverId",
receiverId);
}
return receiverId;
}
/**
* Stop long polling
*
* @name LongPollingChannelMessageReceiver#stop
* @function
*/
this.stop = function stop() {
communicationModule.atmosphere.unsubscribeUrl(channelUrl);
};
/**
* Removes the channel with a given channel id
*
* @name LongPollingChannelMessageReceiver#clear
* @function
*
* @returns {Object} a promise object for async event handling
*/
this.clear =
function clear() {
log.debug("clearing channel with id " + channelId + " and url " + channelUrl);
return communicationModule.createXMLHTTPRequest({
type : "DELETE",
url : channelUrl,
timeout : channelOpMessagingQos.ttl
}).then(function() {
return;
}).catch(function(xhr, errorType) {
var errorString =
"error while deleting channel on bounce proxy: "
+ errorType
+ (xhr.statusText ? (", " + xhr.statusText) : "")
+ (xhr.status === 0 ? "" : (", HTTP" + xhr.status))
+ (xhr.responseText ? (", " + xhr.responseText) : "");
log.error(
"error while deleting channel on bounce proxy",
JSON.stringify(DiagnosticTags.forChannel({
channelId : channelId,
channelUrl : channelUrl,
status : xhr.status,
responseText : xhr.responseText
})));
throw new Error(errorString);
});
};
/**
* Start long polling. Side effect: first makes sure that the channel exists on the bounceproxy
*
* @name LongPollingChannelMessageReceiver#start
* @function
*
* @param {Function}
* onMessageCallback callback used to pass the received messages up the processing chain
* @param {Function}
* onError callback used to inform about errors occurred during message recieve
*/
this.start =
function start(onMessageCallback, onError) {
var pollRequest;
var receiverId = getReceiverId(channelId);
communicationModule.atmosphere.unsubscribeUrl(channelUrl);
pollRequest = {
url : channelUrl,
transport : "long-polling",
contentType : "application/json",
timeout : 30000,
enableXDR : false,
enableProtocol : false,
readResponseHeaders : false,
attachHeadersAsQueryString : false,
dropAtmosphereHeaders : true,
dropHeaders : false,
logLevel : "debug",
headers : {
"X-Atmosphere-tracking-id" : receiverId
}
};
// Called whenever one or more new
// messages are received
// from the bounceproxy.
pollRequest.onMessage =
function onMessage(response) {
var detectedTransport = response.transport, data, jsonParser, joynrMessage;
try {
if (response.status === 200) {
data = response.responseBody;
if (data.length > 0) {
jsonParser = new JsonParser(data);
while (jsonParser.hasNext) {
// pass the message on
joynrMessage = new JoynrMessage(jsonParser.next);
log
.info(
"received message",
JSON
.stringify(DiagnosticTags
.forJoynrMessage(joynrMessage)));
onMessageCallback(joynrMessage);
}
}
}
} catch (e) {
log.debug("Exception while processing message: "
+ e.message);
if (onError) {
onError(e);
}
}
};
pollRequest.onError = function(response) {
log.debug("Encountered atmosphere error :" + response.error);
if (onError) {
onError(response.error);
}
};
communicationModule.atmosphere.subscribe(pollRequest);
log.debug("starting to listen on channel with id "
+ channelId
+ " and url "
+ channelUrl);
};
var callCreate = function callCreate(){
var createChannelUrl =
bounceProxyChannelBaseUrl
+ "?ccid="
+ encodeURIComponent(channelId);
var receiverId = getReceiverId(channelId);
return communicationModule.createXMLHTTPRequest({
type : "POST",
url : createChannelUrl,
headers : {
"X-Atmosphere-tracking-id" : receiverId
},
timeout : channelOpMessagingQos.ttl
}).then(function(xhr) {
channelUrl = xhr.getResponseHeader("Location");
if (!channelUrl) {
channelUrl = xhr.responseText;
}
log.debug("created channel with id "
+ channelId
+ " and url "
+ channelUrl);
return channelUrl;
});
};
function logChannelCreationError(xhr){
log.error(
"error while creating channel on bounce proxy",
{
channelId : channelId,
channelUrl : channelUrl,
status : xhr.status,
responseText : xhr.responseText
});
}
var createInternal = function createInternal(resolve, reject) {
callCreate().then(resolve).catch(function(xhr, errorType) {
logChannelCreationError(xhr);
if (createChannelTimestamp + channelCreationTimeout_ms <= Date.now()) {
reject(new Error("Error creating channel"));
} else {
LongTimer.setTimeout(createInternal, channelCreationRetryDelay_ms, resolve, reject);
}
});
};
/**
* Create the given Channel on the bounceproxy
*
* @name LongPollingChannelMessageReceiver#create
* @function
*
* @param {String}
* channelId the channelId that will be created, will be URI-Component-encoded
* @returns {Object} a promise object for async event handling
*/
this.create = function create(theChannelId) {
if (channelId !== undefined) {
throw new Error("LongPollingChannelMessageReceiver.create has already been called for channelId: " + theChannelId);
}
channelId = theChannelId;
createChannelTimestamp = Date.now();
return callCreate().catch(function(xhr, errorType) {
logChannelCreationError(xhr);
if (createChannelTimestamp + channelCreationTimeout_ms <= Date.now()) {
throw new Error("Error creating channel");
} else {
return new Promise(function(resolve, reject) {
LongTimer.setTimeout(createInternal, channelCreationRetryDelay_ms, resolve, reject);
});
}
});
};
/**
* Parse incoming JSON
*
* @name LongPollingChannelMessageReceiver#parse
* @function
* @private
*/
function parse(data) {
if (window.JSON && window.JSON.parse) {
try {
return window.JSON.parse(data);
} catch (err) {
return data;
}
}
}
}
return LongPollingChannelMessageReceiver;
});© 2015 - 2025 Weber Informatics LLC | Privacy Policy