# Hash2Pub

***This is heavily WIP and does not provide any useful functionality yet***.  
I aim for always having the master branch at a state where it builds and tests pass.

A fully-decentralised relay for global hashtag federation in [ActivityPub](https://activitypub.rocks) based on a distributed hash table.
It allows querying and subscribing to all posts of a certain hashtag and is implemented in Haskell.

This is the practical implementation of the concept presented in the paper [Decentralised Hashtag Search and Subscription for Federated Social Networks](https://git.orlives.de/schmittlauch/paper_hashtag_federation). A 30 minutes [introduction talk](https://conf.tube/videos/watch/340eb706-28c0-4a43-9364-700297ca96cb) is available as well.

The ASN.1 module schema used for DHT messages can be found in `FediChord.asn1`.

## Building

The project and its developent environment are built with [Nix](https://nixos.org/nix/).

The development environment can be entered with `nix-shell shell-minimal.nix`. Then the project can be built with `cabal build` from within the environment, or using `nix-shell --command "cabal build" shell-minimal.nix` to do both steps at once.

While the `shell-minimal.nix` environment contains everything necessary for building and testing this project, the `shell.nix` additionally contains the Haskell IDE engine *hie* and the documentation for all used Haskell packages for more convenient development.  
Be aware that these need to be build from source and can take a very long time to build.