Rocket

Rocket is web framework for Rust (nightly) with a focus on ease-of-use, expressibility, and speed. Here's an example of a complete Rocket application:

#![feature(plugin, decl_macro)]
#![plugin(rocket_codegen)]

extern crate rocket;

#[get("/<name>/<age>")]
fn hello(name: String, age: u8) -> String {
    format!("Hello, {} year old named {}!", age, name)
}

fn main() {
    rocket::ignite().mount("/hello", routes![hello]).launch();
}

Visiting localhost:8000/hello/John/58, for example, will trigger the hello route resulting in the string Hello, 58 year old named John! being sent to the browser. If an <age> string was passed in that can't be parsed as a u8, the route won't get called, resulting in a 404 error.

Documentation

Rocket is extensively documented:

• Overview: A brief look at what makes Rocket special.
• Quickstart: How to get started as quickly as possible.
• Getting Started: How to start your first Rocket project.
• Guide: A detailed guide and reference to Rocket.
• API Documentation: The "rustdocs".

The official community support channels are the #rocket IRC channel on the Mozilla IRC Server at irc.mozilla.org and the bridged Rocket room on Matrix. If you're not familiar with IRC, we recommend chatting through Matrix via Riot or via the Kiwi web IRC client. You can learn more about IRC via Mozilla's Getting Started with IRC guide.

Building

Nightly

Rocket requires a nightly version of Rust as it makes heavy use of syntax extensions. This means that the first two unwieldly lines in the introductory example above are required. Due to an issue in a Rocket dependency (see #513), you must currently build released versions of Rocket with a nightly between nightly-2017-12-18 and nightly-2017-12-21. The in-development version of Rocket compiles with the latest nightly compiler.

Core, Codegen, and Contrib

All of the Rocket libraries are managed by Cargo. As a result, compiling them is simple.

• Core: cd lib && cargo build
• Codegen: cd codegen && cargo build
• Contrib: cd contrib && cargo build --all-features

Examples

Rocket ships with an extensive number of examples in the examples/ directory which can be compiled and run with Cargo. For instance, the following sequence of commands builds and runs the Hello, world! example:

cd examples/hello_world
cargo run

You should see Hello, world! by visiting http://localhost:8000.

Testing

To test Rocket, simply run ./scripts/test.sh from the root of the source tree. This will build and test the core, codegen, and contrib libraries as well as all of the examples. This is the script that gets run by Travis CI. To test a crate individually, run cargo test --all-features.

Core

Testing for the core library is done inline in the corresponding module. For example, the tests for routing can be found at the bottom of the lib/src/router/mod.rs file.

Codegen

Code generation tests can be found in codegen/tests. We use the compiletest library, which was extracted from rustc, for testing. See the compiler test documentation for information on how to write compiler tests.

Documentation

You can build the Rocket API documentation locally by running ./scripts/mk-docs.sh. The resulting documentation is what gets uploaded to api.rocket.rs.

Contributing

Contributions are absolutely, positively welcome and encouraged! Contributions come in many forms. You could:

1. Submit a feature request or bug report as an issue.
2. Ask for improved documentation as an issue.
3. Comment on issues that require feedback.
4. Contribute code via pull requests.

We aim to keep Rocket's code quality at the highest level. This means that any code you contribute must be:

• Commented: Public items must be commented.
• Documented: Exposed items must have rustdoc comments with examples, if applicable.
• Styled: Your code should be rustfmt'd when possible.
• Simple: Your code should accomplish its task as simply and idiomatically as possible.
• Tested: You must add (and pass) convincing tests for any functionality you add.
• Focused: Your code should do what it's supposed to do and nothing more.

All pull requests are code reviewed and tested by the CI. Note that unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in Rocket by you shall be dual licensed under the MIT License and Apache License, Version 2.0, without any additional terms or conditions.

Performance

Rocket is designed to be performant. At this time, its performance is bottlenecked by the Hyper HTTP library. Even so, Rocket currently performs significantly better than the latest version of multithreaded asynchronous Hyper on a simple "Hello, world!" benchmark. Rocket also performs significantly better than the Iron web framework:

Machine Specs:

• Logical Cores: 12 (6 cores x 2 threads)
• Memory: 24gb ECC DDR3 @ 1600mhz
• Processor: Intel Xeon X5675 @ 3.07GHz
• Operating System: Mac OS X v10.11.6

Rocket v0.2-rc (8 LOC) results (best of 3, +/- 2000 req/s, +/- 5us latency):

Running 10s test @ http://localhost:80
  1 threads and 18 connections
  Thread Stats   Avg      Stdev     Max   +/- Stdev
    Latency   153.01us   42.25us 449.00us   75.54%
    Req/Sec    75.58k    11.75k   90.22k    54.46%
  758044 requests in 10.10s, 105.55MB read
Requests/sec:  75051.28
Transfer/sec:     10.45MB

Hyper v0.10-rotor (1/12/2016) (46 LOC) results (best of 3, +/- 5000 req/s, +/- 30us latency):

Running 10s test @ http://localhost:80
  1 threads and 18 connections
  Thread Stats   Avg      Stdev     Max   +/- Stdev
    Latency   287.81us   77.09us 606.00us   70.47%
    Req/Sec    59.94k     6.01k   79.72k    71.00%
  596231 requests in 10.00s, 83.02MB read
Requests/sec:  59621.32
Transfer/sec:      8.30MB

Iron v0.5.0 (11 LOC) results (best of 3, +/- 3000 req/s, +/- 500us latency):

Running 10s test @ http://localhost:80
  1 threads and 18 connections
  Thread Stats   Avg      Stdev     Max   +/- Stdev
    Latency   512.36us    5.57ms 149.99ms   99.60%
    Req/Sec    58.25k    11.61k   70.47k    46.00%
  579227 requests in 10.00s, 80.65MB read
Requests/sec:  57920.73
Transfer/sec:      8.06MB

Summary:

• Rocket throughput higher by 25.9% (higher is better) compared to Hyper.
• Rocket throughput higher by 29.6% (higher is better) compared to Iron.
• Rocket latency lower by 46.8% (lower is better) compared to Hyper.
• Rocket latency lower by 70.1% (lower is better) compared to Iron.

Future Improvements

Rocket is currently built on a synchronous HTTP backend. Once the Rust asynchronous I/O libraries have stabilized, a migration to a new, more performant HTTP backend is planned. We expect performance to improve significantly at that time. The Stabilize HTTP Library issue tracks the progress on this front.

License

Rocket is licensed under either of the following, at your option:

• Apache License, Version 2.0, (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT License (LICENSE-MIT or http://opensource.org/licenses/MIT)

The Rocket website source is licensed under separate terms.