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#![deny(warnings)] #![deny(unsafe_code)] //! aitch is a simple, lightweight toolkit for building HTTP servers in safe, stable Rust. //! //! It builds upon the [`http` crate], and provides additional types for representing HTTP handlers, //! bodies and middlewares. It provides both [`hyper`] and [`tiny_http`] backends for running //! handlers, but aims to be agnostic of the HTTP server library. //! //! It's inspired by the simplicity (and popularity) of Go's [`net/http` package], which builds //! applications/middlewares as a series of nested [`Handler`s]. //! //! [`http` crate]: https://github.com/hyperium/http //! [`hyper`]: https://hyper.rs/ //! [`tiny_http`]: https://github.com/tiny-http/tiny-http //! [`net/http` package]: https://golang.org/pkg/net/http/ //! [`Handler`s]: https://golang.org/pkg/net/http/#Handler //! //! # Defining Handler functions //! //! Handlers are typically defined as functions with the signature: //! //! ```ignore //! Fn(http::Request<impl Body>, http::response::Builder) -> impl Responder //! ``` //! //! Both synchronous and asychronous handlers are defined using this same signature. //! //! A [`Responder`] is anything that implements `IntoFuture<Item = http::Response<impl Body>>`, //! whose `Error` can be converted into a `Box<Error>`. This will often be a [`Result`] for //! synchronous handlers, or something implementing [`Future`] for asynchronous handlers. //! //! For example, to define a simple sychronous handler as a function: //! //! ``` //! # extern crate aitch; //! # extern crate http; //! # //! # use aitch::Responder; //! # //! fn handler(_: http::Request<()>, mut resp: http::response::Builder) -> impl Responder { //! resp.body("Hello, world!".to_owned()) //! } //! ``` //! //! [`Responder`]: trait.Responder.html //! [`Result`]: https://doc.rust-lang.org/std/result/enum.Result.html //! [`Future`]: https://docs.rs/futures/0.1.23/futures/future/trait.Future.html //! //! ### More complex Handlers using the `Handler` trait //! //! Handlers aren't limited to functions - any type that implements the [`Handler`] trait can be used. //! //! For an example of how to implement the [`Handler`] trait for a more complex type, see the //! provided [`SimpleRouter`], which routes HTTP requests to one of many handlers, based on the path //! in the HTTP request. //! //! [`Handler`]: trait.Hander.html //! [`SimpleRouter`]: struct.SimpleRouter.html //! //! # Serving Requests //! //! In order for a `Handler` to serve requests, it needs to be passed to a server which can process //! HTTP requests. //! //! aitch comes with two server implementations: //! //! - [`aitch::servers::hyper::Server`], which uses [`hyper`] to receive and process requests. As //! [`hyper`] can take full advantage of asynchronous I/O, this server backend can support //! streaming request/response bodies. //! - [`aitch::servers::tiny_http::Server`], which uses [`tiny_http`] to receive and process //! requests. [`tiny_http`] uses a thread-pool to synchronously process each request, and the //! entire request body will be buffered before being past to the Handler - there is no support //! for streaming bodies. //! //! The following example demonstrates passing a Handler function to //! [`aitch::servers::hyper::Server`], which allows it to listen and respond to requests: //! //! ```no_run //! # extern crate aitch; //! # extern crate http; //! # //! # use aitch::{middlewares, Responder, ResponseBuilder, Result}; //! # use http::Request; //! # //! # fn handler(_req: Request<()>, mut resp: ResponseBuilder) -> impl Responder { //! # resp.body("Hello, world!".to_owned()) //! # } //! # //! # fn main() -> Result<()> { //! let addr = "127.0.0.1:3000".parse()?; //! aitch::servers::hyper::Server::new(addr, handler)?.run() //! # } //! ``` //! //! aitch aims to be agnostic of the server technology, and it should be possible to add support for //! other servers in third-party crates. The source code of the two provided server implementations //! should demonstrate how to do this. //! //! [`aitch::servers::hyper::Server`]: servers/hyper/struct.Server.html //! [`aitch::servers::tiny_http::Server`]: servers/tiny_http/struct.Server.html //! //! # Request/Response Bodies //! //! The [`http::Request<B>`] and [`http::Response<B>`] types from the [`http` crate] do not restrict //! the type of the body used in requests and bodies. //! //! The [`Body`] trait is used by aitch to place some contraints on the body types used, so that handlers, //! middlewares and servers can make assumptions about how to deserialize it from the raw HTTP //! request, and how they should be serialized to the raw HTTP responses. //! //! [`http::Request<B>`]: https://docs.rs/http/0.1.7/http/request/struct.Request.html //! [`http::Response<B>`]: https://docs.rs/http/0.1.7/http/response/struct.Response.html //! [`http` crate]: https://github.com/hyperium/http //! [`Body`]: trait.Body.html //! //! # Writing Middlewares //! //! In the context of aitch, a middleware is anything that takes one [`Handler`] and returns another //! (possibly modified) [`Handler`]. //! //! The simplest middleware, which does nothing but return the provided [`Handler`] is written as: //! //! ``` //! # use aitch::{Body, Handler}; //! # //! fn noop_middleware<B: Body>(handler: impl Handler<B>) -> impl Handler<B> { //! handler //! } //! ``` //! //! Middlewares may mutate the [`http::response::Builder`] before calling their wrapped handler, in //! order to modify the response that will be returned: //! //! [`http::response::Builder`]: https://docs.rs/http/0.1.7/http/response/struct.Builder.html //! //! ``` //! # extern crate aitch; //! # extern crate http; //! # //! # use aitch::{Body, Handler}; //! # //! fn with_served_by<B: Body>(handler: impl Handler<B>) -> impl Handler<B> { //! move |req, mut resp: http::response::Builder| { //! resp.header("X-Served-By", "aitch"); //! // Middleware authors should be aware that the wrapped handler is //! // under no obligation to use the provided `http::response::Builder`. //! handler.handle(req, resp) //! } //! } //! ``` //! //! aitch provides some sample [middlewares], which provide more detailed examples of how //! third-party applications can create their own middleware. //! //! [middlewares]: ./middlewares/index.html extern crate bytes; extern crate futures; extern crate http; #[cfg(feature = "json")] extern crate serde; #[cfg(feature = "json")] extern crate serde_json; #[cfg(feature = "mime_guess")] extern crate mime_guess; #[cfg(feature = "server-hyper")] extern crate hyper; #[cfg(feature = "server-tiny-http")] extern crate tiny_http; #[cfg(feature = "server-tiny-http")] extern crate tokio_threadpool; mod body; mod handler; pub mod handlers; #[cfg(feature = "json")] mod json; pub mod middlewares; mod responder; pub mod servers; use std::error::Error as StdError; use futures::Future; pub use body::{Body, BodyStream}; pub use handler::{box_handler, BoxedHandler, Handler}; pub use responder::Responder; #[cfg(feature = "json")] pub use json::Json; /// A type alias for [`http::response::Builder`]. /// /// This allows a simpler type signature for handler functions. /// /// # Example /// /// ``` /// # extern crate aitch; /// # extern crate http; /// # /// # use aitch::{ResponseBuilder, Responder}; /// # use http::Request; /// # /// fn handler(_req: Request<()>, mut resp: ResponseBuilder) -> impl Responder { /// resp.body("Hello, world".to_owned()) /// } /// ``` /// /// [`http::response::Builder`]: https://docs.rs/http/0.1.7/http/response/struct.Builder.html pub type ResponseBuilder = http::response::Builder; /// A generic error type for aitch handlers and middlewares. /// /// An error type of `Box<std::error::Error>` is used, so that the error type is as generic as possible /// and can be passed through layers of third-party handlers and middlewares. /// /// In most cases, handlers and middlewares should aim to handle their own errors (and return an /// appropriate HTTP response). Returning an error from a handler should be an exceptional /// circumstance, and will most likely (depending on the middleware/server in use) result in a /// generic HTTP 500 error page. pub type Error = Box<StdError + Send + Sync>; /// A type alias to make working with `Result<T, aitch::Error>` more convenient. pub type Result<T> = ::std::result::Result<T, Error>; /// Represents a future returning a HTTP response, with all types erased. /// /// Handlers which return one of many different [`Responder`] types (e.g. depending on the HTTP /// request details) can use this type to return a generic response, with all type variables erased. /// /// To get a `BoxedResponse`, use the [`Responder::into_response()`] trait method. /// /// [`Responder`]: trait.Responder.html /// [`Responder::into_response()`]: trait.Responder.html#tymethod.into_response /// /// # Example /// /// See [`BoxedHandler`] for an example of its use. /// /// [`BoxedHandler`]: type.BoxedHandler.html pub type BoxedResponse = Box<Future<Item = http::Response<BodyStream>, Error = Error> + Send>;