abci-rs

A Rust crate for creating ABCI applications.

ABCI Overview

ABCI is the interface between Tendermint (a state-machine replication engine) and your application (the actual state machine). It consists of a set of methods, where each method has a corresponding Request and Response message type. Tendermint calls the ABCI methods on the ABCI application by sending the Request messages and receiving the Response messages in return.

ABCI methods are split across 3 separate ABCI connections:

• Consensus Connection: InitChain, BeginBlock, DeliverTx, EndBlock, Commit
• Mempool Connection: CheckTx
• Info Connection: Info, SetOption, Query

Additionally, there is a Flush method that is called on every connection, and an Echo method that is just for debugging.

To know more about ABCI protocol specifications, go to official ABCI documentation.

Usage

Add abci-rs in your Cargo.toml's dependencies section:

toml [dependencies] abci-rs = "0.9"

Each ABCI application has to implement three core traits corresponding to all three ABCI connections, Consensus, Mempool and Info.

Note: Implementations of these traits are expected to be Send + Sync and methods take immutable reference of self. So, internal mutability must be handled using thread safe (Arc, Mutex, etc.) constructs.

After implementing all three above mentioned traits, you can create a Server object and use Server::run() to start ABCI application.

Server::run() is an async function and returns a Future. So, you'll need an executor to drive Future returned from Server::run(). async-std and tokio are two popular options. In counter example, we use tokio's executor.

To know more, go to examples/ to see a sample ABCI application.

Features

• use-tokio: Enables tokio backend for running ABCI TCP/UDS server
  • Enabled by default.
• use-async-std: Enables async-std backend for running ABCI TCP/UDS server
  • Disabled by default.

Features use-tokio and use-async-std are mutually exclusive, i.e., only one of them can be enabled at a time. Compilation will fail if either both of them are enabled or none of them are enabled.

Minimum Supported Versions

• Tendermint: v0.33.4

License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE)
• MIT license (LICENSE-MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.