Previously, 'NamedFile::open()' called a synchronous I/O method. This
commit changes it to instead use tokio's 'File' for async I/O.
To allow this to change, the 'Handler' trait was fixed to enforce that
the lifetime of '&self', the reference to the handler, outlives the
incoming request. As a result, futures returned from a handler can hold
a reference to 'self'.
In summary, this commit modifies 'Responder' so that:
* ..it is no longer 'async'. To accommodate, the 'sized_body' methods
in 'Response' and 'ResponseBuilder' are no longer 'async' and accept
an optional size directly. If none is supplied, Rocket will attempt
to compute the size, by seeking, before writing out the response.
The 'Body' type was also changed to differentiate between its sized
'Seek' and chunked body variants.
* ..'&Request' gains a lifetime: 'r, and the returned 'Response' is
parameterized by a new 'o: 'r. This allows responders to return
references from the request or those that live longer.
The attribute is applied everywhere it can be across the codebase and is
the newly preferred method for launching an application. This commit
also makes '#[rocket::main]` stricter by warning when it is applied to
functions other than 'main'.
observed.
This is a prerequisite for async on_attach fairings. 'Rocket' is now a
builder wrapper around the 'Manifest' type, with operations being
applied when needed by 'launch()', 'Client::new()', or 'inspect()'.
'inspect()' returns an '&Manifest', which now provides the methods that
could be called on an '&Rocket'.
Also:
* Remove 'response::ResultFuture'.
* Re-export 'tokio' and 'futures' from the crate root.
* Make 'ResponseBuilder::sized_body()' and 'async fn'.
* Remove the 'Future' implementation for 'ResponseBuilder'.
* Add 'ResponseBuilder::finalize()' for finalizing the builder.
* Implement `std::error::Error` for the new Error type.
* Document the new Error type.
* Remove `LaunchError`'s implementation of `Error::description`, which is deprecated.
In order to avoid making 'ResponseBuilder::sized_body' an asynchronous
function, the seeking is deferred until finalization. 'finalize()' is
replaced with '.await', and 'ResponseBuilder::ok()' is an 'async fn'.
* Update 'tokio', 'tokio-rustls', and 'hyper'.
* Remove unused dependencies on some `futures-*` crates.
* Rework 'spawn_on', which is now 'serve'.
* Simplify Ctrl-C handling.
Use I/O traits and types from 'tokio-io' as much as possible.
A few adapters only exist in futures-io-preview and use
futures-tokio-compat as a bridge for now.
Types can now implement the new 'Listener' trait, which means they can
report the address they are listening on and asynchronously accept
connections. 'Connection's are read/write streams that can additionally
report the remote address.
Listener is implemented for 'tokio_net::tcp::TcpListener' and for
the new 'rocket_http::tls::TlsListener' based on 'tokio-rustls'.
The new private function 'Rocket::listen_on()' now does the main setup
for launch and is generic over a Listener. In the future, a more refined
version of the API can be exposed so that applications can implement
their own listeners.