BunBun-Worker

<center> <h1> BunBun-Worker </h1> </center>

`bunbun-worker` is a panic-safe multithreaded job-runner server/client library for rust. It supports [RPC](https://wikipedia.org/wiki/Remote_procedure_call) and regular (non-rpc) calls. As of right now only [rabbitmq](https://www.rabbitmq.com/) is supported but [gRPC](https://grpc.io/) will be added too.

> ❗ Disclaimer  
> This crate is still under development, meaning api's may change on every commit...

# Introduction

`bunbun-worker` was made to provide a way for microservices written in rust to communicate to each other by dispatching jobs that may return data and those who don't.

### Rpc

Remote procedure call, as it's name says is a message that can be sent to a remote microservice to be processed and the result to be returned. In `bunbun-worker` it's implemented by the following example:

```mermaid
sequenceDiagram
    ServiceA->>+ServiceB: Hey, could you do this job for me?
    Note right of ServiceB: ServiceB does the job
    ServiceB->>+ServiceA: Sure, here is the data result
```

1. ServiceA creates a callback queue that the response shall be sent to.
2. ServiceA sends a json job message to an **already declared** queue on a rabbitmq server.
3. ServiceB is listening on that queue for messages and spawns a new thread for each received.
4. Once ServiceB has finished the work, using the received messages header it responds to the callback queue with the correlation-id.

### Non-rpc

In `bunbun-worker` regular jobs are called _non-rpc_ jobs, indicating that the response is not awaited.

## Installation

Get directly from crates.io

```toml
[dependencies]
bunbun-worker = { version = "0.1.1" }
```

or get it directly from source

```toml
[dependencies]
bunbun-worker = { git = "https://git.4o1x5.dev/4o1x5/bunbun-worker", branch = "master" }
```

## Usage

### Message versioning

In this crate message versioning is done by including `v1.0.0` or such on the end of the queue name, instead of including it in the headers of a message. This reduces the amount of redelivered messages.  
The following example will send a job to a queue named `emailjob-v1.0.0`.

```rust
let result = client
        .rpc_call::<EmailJob>(
            EmailJob {
                send_to: "someone".into(),
                contents: "something".into(),
            },
            BasicCallOptions::default("emailjob")
                .timeout(Duration::from_secs(3))
                .message_version("v1.0.0")
        )
        .await
        .unwrap();
```

# Limitations

1. Currently some `unwrap()`'s are called inside the code and may results in panics (not in the job-runner).
2. limited API

# Bugs department

Since the code is hosted on a private git instance (as of right now) any bugs shall be discussed in [4o1x5's project room](https://matrix.to/#/#projects:4o1x5.dev).

## License

Licensed under [GNU AFFERO GENERAL PUBLIC LICENSE](https://www.gnu.org/licenses/agpl-3.0.en.html)

### Contribution

Currently this library does not accept any contributors, as it's hosted on a private git server.

# Credits

This package was made with the help of-

- [This readme template you are reading right now](https://github.com/webern/cargo-readme/blob/master/README.md)
- [Lapin, an extensive easy to use rabbitmq client](https://crates.io/crates/lapin)