1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109

//! A message broadcasting library based on the Plumtree/HyParView algorithms.
//!
//! # Properties
//!
//! ## Pros
//!
//! - Nearly optimal message transmitting count
//!   - Usually messages are broadcasted via a spanning tree
//!   - Only the nodes interested in the same messages belong to the same cluster
//! - Scalable
//!   - Theoretically, it can handle ten-thousand of nodes or more
//! - High fault tolerance
//!   - Spanning trees are automatically repaired if there are crashed nodes
//! - Dynamic membership
//!   - Nodes can be added to (removed from) a cluster at any time
//!
//! ## Cons
//!
//! - No strong guarantee about connectivity of the nodes in a cluster
//! - No strong guarantee about delivery count of a message
//! - No guarantee about messages delivery order
//!
//! If some of the above guarantees are mandatory for your application,
//! it is need to be provided by upper layers.
//!
//! # References
//!
//! - [HyParView: a membership protocol for reliable gossip-based broadcast][HyParView]
//! - [Plumtree: Epidemic Broadcast Trees][Plumtree]
//!
//! [HyParView]: http://asc.di.fct.unl.pt/~jleitao/pdf/dsn07-leitao.pdf
//! [Plumtree]: http://www.gsd.inesc-id.pt/~ler/reports/srds07.pdf
#![warn(missing_docs)]
#[macro_use]
extern crate bytecodec;
#[macro_use]
extern crate slog;
#[macro_use]
extern crate trackable;

pub use error::{Error, ErrorKind};

mod codec;
mod error;
mod node_id;
mod node_id_generator;
mod rpc;

pub mod message;
pub mod metrics;
pub mod misc;
pub mod node;
pub mod service;

/// This crate specific `Result` type.
pub type Result<T> = std::result::Result<T, Error>;

#[cfg(test)]
mod tests {
    use crate::node::{Node, SerialLocalNodeIdGenerator};
    use crate::service::Service;
    use fibers::Spawn;
    use futures::{Future, Stream};

    #[test]
    fn it_works() {
        let server_addr = "127.0.0.1:12121".parse().unwrap();
        let service = Service::<String>::new(
            server_addr,
            fibers_global::handle(),
            SerialLocalNodeIdGenerator::new(),
        );
        let service_handle = service.handle();
        fibers_global::spawn(service.map_err(|e| panic!("{}", e)));

        let mut fibers = Vec::new();
        let mut first_node_id = None;
        for i in 0..100 {
            let mut node = Node::new(service_handle.clone());
            if let Some(id) = first_node_id {
                node.join(id);
            } else {
                first_node_id = Some(node.id());
            }
            if i == 99 {
                node.broadcast("hello".to_owned());
            }
            let spawner = fibers_global::handle();
            let fiber = fibers_global::spawn_monitor(
                node.into_future()
                    .map(move |(message, stream)| {
                        spawner.spawn(stream.for_each(|_| Ok(())).map_err(|_| ()));
                        message.map(|m| m.into_payload())
                    })
                    .map_err(|(e, _)| e),
            );
            fibers.push(fiber);
        }

        for fiber in fibers {
            match fibers_global::execute(fiber) {
                Err(e) => panic!("{}", e),
                Ok(message) => {
                    assert_eq!(message, Some("hello".to_owned()));
                }
            }
        }
    }
}