hypercore-protocol 0.3.1

Replication protocol for Hypercore feeds
Documentation
//! Hypercore protocol is a streaming, message based protocol
//!
//! This crate does not include any IO related code, it is up to the user to supply a streaming IO
//! handler that implements the [AsyncRead] and [AsyncWrite] traits.
//!
//! When opening a Hypercore protocol stream on an IO handler, the protocol will perform a Noise
//! handshake to setup a secure and authenticated connection. After that, each side can request any
//! number of channels on the protocol. A channel is opened with a [Key], a 32 byte buffer.
//! Channels are only opened if both peers opened a channel for the same key. It is automatically
//! verified that both parties know the key without transmitting the key itself.
//!
//! On a channel, the predefined messages of the Hypercore protocol can be sent and received.
//! Additionally, Hypercore protocol supports protocol extensions that can be registered both on an
//! individual channel and on the main protocol stream. Extensions are registered with a string
//! name and are only established if both peers register an extension with the same name. Each
//! extension then can be used as a duplex stream. Note that individual messages on an extension
//! stream are enrypted but not authenticated.
//!
//! [AsyncRead]: futures_lite::AsyncRead
//! [AsyncWrite]: futures_lite::AsyncWrite
//! [TcpStream]: async_std::net::TcpStream
//!
//! The following example opens a TCP server on localhost and connects to that server. Both ends
//! then open a channel with the same key and exchange a message.
//!
//! ```no_run
//! # async_std::task::block_on(async {
//! use hypercore_protocol::{ProtocolBuilder, Event, Message};
//! use hypercore_protocol::schema::*;
//! use async_std::prelude::*;
//!
//! // Start a tcp server.
//! let listener = async_std::net::TcpListener::bind("localhost:8000").await.unwrap();
//! async_std::task::spawn(async move {
//!     let mut incoming = listener.incoming();
//!     while let Some(Ok(stream)) = incoming.next().await {
//!         async_std::task::spawn(async move {
//!             onconnection(stream, false).await
//!         });
//!     }
//! });
//!
//! // Connect a client.
//! let stream = async_std::net::TcpStream::connect("localhost:8000").await.unwrap();
//! onconnection(stream, true).await;
//!
//! /// Start Hypercore protocol on a TcpStream.
//! async fn onconnection (stream: async_std::net::TcpStream, is_initiator: bool) {
//!     // A peer either is the initiator or a connection or is being connected to.
//!     let name = if is_initiator { "dialer" } else { "listener" };
//!     // A key for the channel we want to open. Usually, this is a pre-shared key that both peers
//!     // know about.
//!     let key = [3u8; 32];
//!     // Create the protocol.
//!     let mut protocol = ProtocolBuilder::new(is_initiator).connect(stream);
//!
//!     // Iterate over the protocol events. This is required to "drive" the protocol.
//!     while let Some(Ok(event)) = protocol.next().await {
//!         eprintln!("{} received event {:?}", name, event);
//!         match event {
//!             // The handshake event is emitted after the protocol is fully established.
//!             Event::Handshake(_remote_key) => {
//!                 protocol.open(key.clone()).await;
//!             },
//!             // A Channel event is emitted for each established channel.
//!             Event::Channel(mut channel) => {
//!                 // A Channel can be sent to other tasks.
//!                 async_std::task::spawn(async move {
//!                     // A Channel can both send messages and is a stream of incoming messages.
//!                     channel.want(Want { start: 0, length: None }).await;
//!                     while let Some(message) = channel.next().await {
//!                         eprintln!("{} received message: {:?}", name, message);
//!                     }
//!                 });
//!             },
//!             _ => {}
//!         }
//!     }
//! }
//! # })
//! ```

#![forbid(unsafe_code, future_incompatible, rust_2018_idioms)]
#![deny(missing_debug_implementations, nonstandard_style)]
// #![warn(missing_docs, missing_doc_code_examples, unreachable_pub)]
#![warn(missing_docs, missing_doc_code_examples)]

mod builder;
mod channels;
mod constants;
mod duplex;
mod extension;
mod message;
mod noise;
mod protocol;
mod reader;
mod util;
mod writer;

/// The wire messages used by the protocol.
#[allow(missing_docs)]
pub mod schema {
    include!(concat!(env!("OUT_DIR"), "/hypercore.schema.rs"));
    pub use crate::message::ExtensionMessage;
}

pub use builder::{Builder as ProtocolBuilder, Options};
pub use channels::Channel;
pub use duplex::Duplex;
pub use extension::Extension;
pub use message::Message;
pub use protocol::{DiscoveryKey, Event, Key, Protocol};
pub use util::discovery_key;