# kad-quasar > publish-subscribe system for kad Latest version **2.1.0** (published 2017-06-24) · AGPL-3.0 license · 0 weekly downloads > **Deprecated.** This package is deprecated. ## Install ```sh npm install kad-quasar pnpm add kad-quasar yarn add kad-quasar bun add kad-quasar ``` ## Health **Score 10/100 (F)** — status: deprecated. Negative: deprecated. ## Facts | | | |---|---| | Version | 2.1.0 | | Published | 2017-06-24 | | First published | 2016-01-22 | | Weekly downloads | 0 | | License | AGPL-3.0 | | TypeScript types | none | | Module format | CommonJS | | Node | >=6.9.1 | | Dependencies | 7 | | Known vulnerabilities | 0 (+2 in 2 direct dependencies) | | Install scripts | no | | Author | Gordon Hall | | Maintainers | bookchin | | Keywords | kad, publish, subscribe, pubsub, sensor, network | ## Links - npm: https://www.npmjs.com/package/kad-quasar - Repository: https://github.com/kadtools/kad-quasar - Homepage: https://github.com/kadtools/kad-quasar#readme - Issues: https://github.com/kadtools/kad-quasar/issues - npm.io page: https://npm.io/package/kad-quasar ## Dependencies (7) - [kad](https://npm.io/package/kad.md) ^2.3.0 - [atbf](https://npm.io/package/atbf.md) ^1.1.0 - [uuid](https://npm.io/package/uuid.md) ^3.0.0 - [async](https://npm.io/package/async.md) ^2.1.4 - [merge](https://npm.io/package/merge.md) ^1.2.0 - [lru-cache](https://npm.io/package/lru-cache.md) ^4.0.1 - [knuth-shuffle](https://npm.io/package/knuth-shuffle.md) ^1.0.1 ## Alternatives - [async-exit-hook](https://npm.io/package/async-exit-hook.md) — 3.7M weekly downloads - [evnty](https://npm.io/package/evnty.md) — 7.2K weekly downloads - [eleventy-plugin-asciidoc](https://npm.io/package/eleventy-plugin-asciidoc.md) — 3.5K weekly downloads - [@jswork/next-get2get](https://npm.io/package/@jswork/next-get2get.md) — 945 weekly downloads - [@dashersw/axon](https://npm.io/package/@dashersw/axon.md) — 934 weekly downloads ## Recent versions - 2.1.0 (latest) — 2017-06-24 - 2.0.3 — 2017-06-14 - 2.0.2 — 2017-05-30 - 2.0.1 — 2017-05-23 - 1.2.4 — 2017-05-23 - 2.0.0 — 2017-03-20 - 1.2.3 — 2017-02-22 - 1.2.2 — 2017-02-19 - 1.2.1 — 2017-02-19 - 1.2.0 — 2017-02-17 - 1.1.0 — 2017-02-13 - 1.0.2 — 2016-11-08 - 1.0.1 — 2016-10-24 - 1.0.0 — 2016-10-24 - 0.3.3 — 2016-10-15 - … 11 more at https://npm.io/package/kad-quasar/versions ## README Kad Quasar ========== [![Build Status](https://img.shields.io/travis/kadtools/kad-quasar.svg?style=flat-square)](https://travis-ci.org/kadtools/kad-quasar) [![Coverage Status](https://img.shields.io/coveralls/kadtools/kad-quasar.svg?style=flat-square)](https://coveralls.io/r/kadtools/kad-quasar) [![NPM](https://img.shields.io/npm/v/kad-quasar.svg?style=flat-square)](https://www.npmjs.com/package/kad-quasar) Distributed publish-subscribe plugin for [Kad](https://github.com/kadtools/kad), based on [Quasar](http://research.microsoft.com/en-us/um/people/saikat/pub/iptps08-quasar.pdf). Quick Start ----------- Install kad-quasar with NPM: ```bash npm install kad-quasar --save ``` Plugin to your existing Kad project: ```js const kad = require('kad'); const quasar = require('kad-quasar'); const node = kad({ /* options */ }); node.plugin(quasar); node.quasarSubscribe('topic string', (content) => { node.logger.info(content); }); node.quasarPublish('topic string', { some: 'content' }); ``` Overview -------- Kad Quasar extends [Kad](https://github.com/kadtools/kad) with a [publish/subscribe](https://en.wikipedia.org/wiki/Publish%E2%80%93subscribe_pattern) system, enabling different applications to run on the same overlay network. To do this, Kad Quasar uses the routing table's contact list to build an attenuated [bloom filter](https://en.wikipedia.org/wiki/Bloom_filter) where each filter in the series contains topics that your node and your neighbors are subscribed to represented in "hops" from your node. This allows each node to maintain a view of what their neighbors are interested in 3 hops away. Published messages are relayed to neighbors probabilistically based on this knowledge and are appended with negative information to prevent duplication. This forms "gravity wells" in the network around groups who are interested in a given topic and serves to prevent flooding the network while still maintaining a high probability that the message will be delivered to all nodes interested. Class: QuasarNode(options) -------------------------- The `QuasarNode` class decorates the [`KademliaNode`](https://kadtools.github.io/KademliaNode.html) class in Kad. It creates and manages an attenuated bloom filter representing the different topics to which your neighboring nodes are subscribed. ### node.quasarPublish(topic[, content]) Publishes a message to your nearest neighbors on the given `topic` (and optional) `content` object. Those neighbors, in turn, relay the message to their neighbors in accordance with their view of the the network. #### Parameters * `topic` - (String) identifier for the topic * `content` - (Mixed) additional data describing the publication ### node.quasarSubscribe(topic[, handler]) Updates our local attenuated bloom filter to reflect our interest in the topic and notifies our neighbors to relay publications matching the topic to us. In turn, our neighbors will provide us with their local bloom filter, so we can do the same. #### Parameters * `topic` - (String) identifier for the topic * `handler` - (Function) receives arguments `content` with published data License ------- Kad Quasar - Distributed publish-subscribe plugin for Kad Copyright (C) 2017 Gordon Hall This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more details. You should have received a copy of the GNU Affero General Public License along with this program. If not, see http://www.gnu.org/licenses/. --- _Source: https://npm.io/package/kad-quasar · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._