Rocket

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

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

extern crate rocket;

#[get("/<name>/<age>")]
fn hello(name: &str, 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:

• Quickstart: How to get started as quickly as possible.
• Getting Started: How to start your first project.
• Overview: A brief introduction.
• Guide: A detailed guide and reference to every component.
• API Documentation: The "rustdocs" (API documentation).

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.

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

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.

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.

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.

Performance

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

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

Hyper v0.10.0-a.0 (46 LOC) results (best of 3, +/- 300 req/s, +/- 1us latency):

Running 10s test @ http://localhost:80
  2 threads and 10 connections
  Thread Stats   Avg      Stdev     Max   +/- Stdev
    Latency   175.12us   40.38us 429.00us   70.79%
    Req/Sec    28.00k     2.41k   36.79k    72.28%
  562692 requests in 10.10s, 81.57MB read
Requests/sec:  55715.98
Transfer/sec:      8.08MB

Rocket v0.0.11 (8 LOC) results (best of 3, +/- 200 req/s, +/- 0.5us latency):

Running 10s test @ http://localhost:80
  2 threads and 10 connections
  Thread Stats   Avg      Stdev     Max   +/- Stdev
    Latency   163.97us   27.47us 699.00us   70.30%
    Req/Sec    29.58k     1.02k   32.39k    64.85%
  594546 requests in 10.10s, 82.78MB read
Requests/sec:  58868.83
Transfer/sec:      8.20MB

Summary:

• Rocket throughput higher by 5.7% (higher is better).
• Rocket latency lower by 7.4% (lower is better).

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.