A Rust implementation of [gRPC], a high performance, open source, general
RPC framework that puts mobile and HTTP/2 first.
[`tonic`] is a gRPC over HTTP/2 implementation focused on **high
performance**, **interoperability**, and **flexibility**. This library was
created to have first class support of async/await and to act as a core building
block for production systems written in Rust.
# Examples
Examples can be found in the [`tonic-examples`] crate.
# Getting Started
Follow the instructions in the [`tonic-build`] crate documentation.
# Feature Flags
- `transport`: Enables the fully featured, batteries included client and server
implementation based on [`hyper`], [`tower`] and [`tokio`]. Enabled by default.
- `channel`: Enables just the full featured channel/client portion of the `transport`
feature.
- `codegen`: Enables all the required exports and optional dependencies required
for [`tonic-build`]. Enabled by default.
- `tls`: Enables the `rustls` based TLS options for the `transport` feature. Not
enabled by default.
- `tls-roots`: Adds system trust roots to `rustls`-based gRPC clients using the
`rustls-native-certs` crate. Not enabled by default. `tls` must be enabled to use
`tls-roots`.
- `tls-webpki-roots`: Add the standard trust roots from the `webpki-roots` crate to
`rustls`-based gRPC clients. Not enabled by default.
- `prost`: Enables the [`prost`] based gRPC [`Codec`] implementation.
- `compression`: Enables compressing requests, responses, and streams. Note
that you must enable the `compression` feature on both `tonic` and
`tonic-build` to use it. Depends on [flate2]. Not enabled by default.
# Structure
## Generic implementation
The main goal of [`tonic`] is to provide a generic gRPC implementation over HTTP/2
framing. This means at the lowest level this library provides the ability to use
a generic HTTP/2 implementation with different types of gRPC encodings formats. Generally,
some form of codegen should be used instead of interacting directly with the items in
[`client`] and [`server`].
## Transport
The [`transport`] module contains a fully featured HTTP/2.0 [`Channel`] (gRPC terminology)
and [`Server`]. These implementations are built on top of [`tokio`], [`hyper`] and [`tower`].
It also provides many of the features that the core gRPC libraries provide such as load balancing,
tls, timeouts, and many more. This implementation can also be used as a reference implementation
to build even more feature rich clients and servers. This module also provides the ability to
enable TLS using [`rustls`], via the `tls` feature flag.
[gRPC]: https://grpc.io
[`tonic`]: https://github.com/hyperium/tonic
[`tokio`]: https://docs.rs/tokio
[`prost`]: https://docs.rs/prost
[`hyper`]: https://docs.rs/hyper
[`tower`]: https://docs.rs/tower
[`tonic-build`]: https://docs.rs/tonic-build
[`tonic-examples`]: https://github.com/hyperium/tonic/tree/master/examples
[`Codec`]: codec/trait.Codec.html
[`Channel`]: transport/struct.Channel.html
[`Server`]: transport/struct.Server.html
[`rustls`]: https://docs.rs/rustls
[`client`]: client/index.html
[`transport`]: transport/index.html
[flate2]: https://crates.io/crates/flate2