https://github.com/MarinPostma/raft-frp

raft, for regular people
https://github.com/MarinPostma/raft-frp

Last synced: 5 days ago
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raft, for regular people

• Host: GitHub
• URL: https://github.com/MarinPostma/raft-frp
• Owner: MarinPostma
• Archived: true
• Created: 2020-08-12T14:41:17.000Z (over 4 years ago)
• Default Branch: master
• Last Pushed: 2020-10-27T08:22:33.000Z (about 4 years ago)
• Last Synced: 2024-08-03T09:12:19.432Z (4 months ago)
• Language: Rust
• Size: 87.9 KB
• Stars: 7
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
# This project is not maintained anymore

# RAFT, for regular people

This is an attempt to create a layer on top of

[tikv/raft-rs](https://github.com/tikv/raft-rs), that is easier to use and

implement. This is not supposed to be the most featureful raft, but instead a

convenient interface to get started quickly, and have a working raft in no

time.

The interface is strongly inspired by the one used by [canonical/raft](https://github.com/canonical/raft).

## Getting started

In order to "raft" storage, we need to implement the `Storage` trait for it.

Bellow is an example with `HashStore`, which is a thread-safe wrapper around an

`HashMap`:

```rust

/// convienient data structure to pass Message in the raft

#[derive(Serialize, Deserialize)]

pub enum Message {

    Insert { key: u64, value: String },

}

#[derive(Clone)]

struct HashStore(Arc>>);

impl Store for HashStore {

    type Error = RaftError;

    fn apply(&mut self, message: &[u8]) -> Result, Self::Error> {

        let message: Message = deserialize(message).unwrap();

        let message: Vec = match message {

            Message::Insert { key, value } => {

                let mut db = self.0.write().unwrap();

                db.insert(key, value.clone());

                serialize(&value).unwrap()

            }

        };

        Ok(message)

    }

    fn snapshot(&self) -> Vec {

        serialize(&self.0.read().unwrap().clone()).unwrap()

    }

    fn restore(&mut self, snapshot: &[u8]) -> Result<(), Self::Error> {

        let new: HashMap = deserialize(snapshot).unwrap();

        let mut db = self.0.write().unwrap();

        let _ = std::mem::replace(&mut *db, new);

        Ok(())

    }

}

```

Only 3 methods need to be implemented for the Store: 

- `Store::apply`: applies a commited entry to the store.  

- `Store::snapshot`: returns snapshot data for the store. 

- `Store::apply`: applies the snapshot passed as argument.

### running the raft

```rust

#[tokio::main]

fn main() {

    let store = HashStore::new();

    let raft = Raft::new(options.raft_addr, store.clone());

    let mailbox = Arc::new(raft.mailbox());

    let (raft_handle, mailbox) = match options.peer_addr {

        Some(addr) => {

            info!("running in follower mode");

            let handle = tokio::spawn(raft.join(addr));

            (handle, mailbox)

        }

        None => {

            info!("running in leader mode");

            let handle =  tokio::spawn(raft.lead());

            (handle, mailbox)

        }

    };

    

    tokio::join!(raft);

}

```

The `mailbox` gives you a way to interact with the raft, for sending a message, or leaving the cluster for example.