bunbun-worker/readme.md

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

A multithreaded _panic-safe_ job runner built on the AMQP. Bunbun-worker features RPC and nonRPC calls, and can handle multiple types of messages at a time.

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

## Installation

Since this package is not published to crates.io you will need to add it manually to `Cargo.toml`

```toml
[dependencies]
bunbun-worker = { git = "https://git.4o1x5.dev/4o1x5/bunbun-worker", version = "0.12" }
```

or

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

## Motivation

I have a project called _Mediarose_ in development and I needed a way to have efficient and simple communication between services to kill of circular dependencies.

## Usage

Here is a basic implementation of an RPC job in bunbun-worker

```rust
// server

// First let's create a state that will be used inside a job.
// Imagine this holding a database connection, some context that may need to be changed. Anything really
#[derive(Clone, Debug)]
pub struct State {
    pub something: String,
}

/// Second, let's create a job, with field that can be serialized/deserialized into JSON
/// This is what the server will receive from a client and will do the job based on these properties
#[derive(Deserialize, Serialize, Clone, Debug)]
pub struct EmailJob {
    send_to: String,
    contents: String,
}
// We also create a result for it, since it's an RPC job
#[derive(Deserialize, Serialize, Clone, Debug, PartialEq)]
pub struct EmailJobResult {
    contents: String,
}
// And an error type so know if the other end errored out, what to do.
#[derive(Deserialize, Serialize, Clone, Debug)]
pub enum EmailJobResultError {
    Errored,
}

/// After all this we implement a Jobrunner/Taskrunner to the type, so when the listener receives it, it can run this piece of code.
impl RPCServerTask for EmailJob {
    type ErroredResult = EmailJobResultError;
    type Result = EmailJobResult;
    type State = State;
    fn run(
        self,
        state: Arc<Mutex<Self::State>>,
    ) -> futures::prelude::future::BoxFuture<'static, Result<Self::Result, Self::ErroredResult>>
    {
        Box::pin(async move {
            tracing::info!("Sent email to {}", self.send_to);
            tokio::time::sleep(Duration::from_secs(2)).await;
            return Ok(EmailJobResult {
                contents: self.contents.clone(),
            });
        })
    }
}
// Finally, we can define an async main function to run the listener in.
#[tokio::main]
async fn main(){
    // Define a listener, with a hard-limit of 100 jobs at once.
    let mut listener =
        BunBunWorker::new(env::var("AMQP_SERVER_URL").unwrap(), 100.into()).await;
    // Add the defined sturct to the worker
    listener
        .add_rpc_consumer::<EmailJob>(
            "email-emailjob-v1.0.0", // queue name
            "emailjob", // consumer tag
            Arc::new(Mutex::new(State {
                something: "test".into(), // putting our state into a Arc<Mutex<S>> for thread safety
            })),
        )
        .await;
    tracing::debug!("Starting listener");
    // Starting the listener
    listener.start_all_listeners().await;
}
```

```rust
// client

// Define the same structs we did. These are DTO's after all..
#[derive(Deserialize, Serialize, Clone, Debug)]
pub struct EmailJob {
    send_to: String,
    contents: String,
}
#[derive(Deserialize, Serialize, Clone, Debug, PartialEq)]
pub struct EmailJobResult {
    contents: String,
}
#[derive(Deserialize, Serialize, Clone, Debug)]
pub enum EmailJobResultError {
    Errored,
}
// Now we implement the clientside task for it. This reduces generics when defining the calling..
impl RPCClientTask for EmailJob {
    type ErroredResult = EmailJobResultError;
    type Result = EmailJobResult;
}

#[tokio::main]
async fn main(){
// Define a client
  let mut client = BunBunClient::new(env::var("AMQP_SERVER_URL").unwrap().as_str())
      .await
      .unwrap();
  // Make a call
  let result = client
      .rpc_call::<EmailJob>(
            // Define the job
          EmailJob {
              send_to: "someone".into(),
              contents: "something".into(),
          },
          "email-emailjob-v1.0.0", // the queue name
      )
      .await
      .unwrap();
}
```

## 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 registry and 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)