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JOYnr JavaScript libjoynr-js
/*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/routing/LocalChannelUrlDirectory",
[
"global/Promise",
"joynr/util/UtilInternal"
],
function(Promise, Util) {
/**
* The LocalChannelUrlDirectory resolves channel IDs to channel URLs and maintains a local list as well as registering with the global
* list. Channel IDs can be mapped on multiple channel URLs depending on network topology and reach-ability.
*
* @name LocalChannelUrlDirectory
* @constructor
*
* @param {Object}
* settings used to configure LocalChannelUrlDirectory
* @param {ChannelUrlDirectoryProxy}
* settings.channelUrlDirectoryProxy handles communication with the global channelurlDirectory
* @param {Object}
* [settings.provisionedChannelUrls] preprovisioned channel URLs
* @param {Array}
* settings.provisionedChannelUrls.CHANNELID a list of channel urls
* @param {String}
* settings.provisionedChannelUrls.CHANNELID.array a string containing a Channel URL
*
* @classdesc The LocalChannelUrlDirectory maps known ChannelIds to ChannelUrls. Unknown channelIds are looked up in the Global
* ChannelUrlDirectory
*/
var LocalChannelUrlDirectory =
function(settings) {
var channelUrlDirectoryProxy, channelIdtoChannelUrlsMap, promiseLookups =
{};
Util.checkProperty(settings, "Object", "settings");
Util.checkPropertyIfDefined(
settings.provisionedChannelUrls,
"Object",
"settings.provisionedChannelUrls");
channelUrlDirectoryProxy = settings.channelUrlDirectoryProxy;
channelIdtoChannelUrlsMap =
Util.extend({}, settings.provisionedChannelUrls);
/**
* @name LocalChannelUrlDirectory#isStale
* @function
* @private
*
* @param {Number}
* lastUpdated
* @param {Number}
* freshness_ms
* @returns {Boolean} if the entry is stale
*/
function isStale(lastUpdated, freshness_ms) {
// if lastUpdated is not set, then always considered to be fresh
return Date.now() - lastUpdated > freshness_ms;
}
/**
* Registers channelId and channelUrl information. The channel URL information is used to send messages to a Cluster Controller
* identified by the unique channel ID.
*
* @name LocalChannelUrlDirectory#registerChannelUrls
* @function
*
* @param {Object}
* operationArguments - object containing properties required for the operation
* @param {Object}
* operationArguments.channelId - the channel ID to register channel URL information with
* @param {ChannelUrlInformation}
* operationArguments.channelUrlInformation - the channel URL information used to send messages to a Cluster Controller
* @returns {Object} A+ promise object
*/
this.registerChannelUrls =
function registerChannelUrls(operationArguments) {
// lastUpdated not set because this is a local entry with no
// need to query global for freshness
channelIdtoChannelUrlsMap[operationArguments.channelId] =
operationArguments.channelUrlInformation;
return channelUrlDirectoryProxy
.registerChannelUrls(operationArguments);
};
/**
* Causes the channelUrls to be removed from the local cache and unregistered on the Global ChannelUrlDirectory
*
* @name LocalChannelUrlDirectory#unregisterChannelUrls
* @function
*
* @param {Object}
* operationArguments - object containing properties required for the operation
* @param {Object}
* operationArguments.channelId - the channel ID to register channel URL information with
* @returns {Object} A+ promise object
*/
this.unregisterChannelUrls =
function unregisterChannelUrls(operationArguments) {
delete channelIdtoChannelUrlsMap[operationArguments.channelId];
return channelUrlDirectoryProxy
.unregisterChannelUrls(operationArguments);
};
/**
* @name LocalChannelUrlDirectory#getUrlsForChannel
* @function
*
* @param {Object}
* operationArguments - object containing properties required for the operation
* @param {Object}
* operationArguments.channelId - the channel ID to register channel URL information with
* @param {Number}
* freshness_ms
* @returns {Object} A+ promise object
*/
this.getUrlsForChannel =
function getUrlsForChannel(operationArguments, freshness_ms) {
var channelId, channelUrls, promise;
channelId = operationArguments.channelId;
channelUrls = channelIdtoChannelUrlsMap[channelId];
promise = promiseLookups[channelId];
if (promise !== undefined) {
return promise;
}
// if missing or stale, lookup from global
if ((channelUrls === undefined || isStale(channelUrls.lastUpdated, freshness_ms))) {
promiseLookups[channelId] = channelUrlDirectoryProxy.getUrlsForChannel(operationArguments).then(
function(opArgs) {
if (opArgs.result === undefined) {
delete promiseLookups[channelId];
throw new Error("Could not retrieve URLs for channel "
+ operationArguments.channelId
+ ": resolved channelUrls are not defined.");
} else {
var channelUrlWithDate =
Util.extend(opArgs.result,
{
lastUpdated : Date.now()
});
channelIdtoChannelUrlsMap[operationArguments.channelId] =
channelUrlWithDate;
delete promiseLookups[channelId];
return channelIdtoChannelUrlsMap[operationArguments.channelId];
}
}).catch(function(error) {
delete promiseLookups[channelId];
throw new Error(
"Could not retrieve URLs for channel "
+ operationArguments.channelId
+ ": "
+ error);
});
return promiseLookups[channelId];
}
return Promise.resolve(channelUrls);
};
};
return LocalChannelUrlDirectory;
});© 2015 - 2025 Weber Informatics LLC | Privacy Policy