Make it possible to refer to Connected, Connection, HttpConnector, etc.
without enabling either of the http1/http2 features. This makes feature
selection work better for downstream libraries like hyper-openssl, which
don't want to commit to any particular protocol.
Fix#2376.
The DNS resolver part of `HttpConnector` used to require resolving to
`IpAddr`s, and this changes it so that they resolve to `SocketAddr`s.
The main benefit here is allowing for resolvers to set the IPv6 zone ID
when resolving, but it also just more closely matches
`std::net::ToSocketAddrs`.
Closes#1937
BREAKING CHANGE: Custom resolvers used with `HttpConnector` must change
to resolving to an iterator of `SocketAddr`s instead of `IpAddr`s.
cc #2251
BREAKING CHANGE: This puts all HTTP/2 methods and support behind an
`http2` cargo feature, which will not be enabled by default. To use
HTTP/2, add `features = ["http2"]` to the hyper dependency in your
`Cargo.toml`.
Currently HttpConnector::set_local_address method accepts a single
argument. Server might not support IPv6 or IPv4. Therefore, the only
solution at the moment is to manually perform DNS resolution and pick
appropriate local address family. This is inefficient, as leads to
2 DNS lookups per request. This commit allows specifying both IPv4
and IPv6, so connector can decide which one to use based on DNS
resolution results.
If the runtime is dropped while a DNS request is being made, it can
lead to a panic. This patch checks if the task was cancelled, and
returns a generic IO error instead of panicking in that case.
The following code reproduces the problem on my macOS machine:
```
use hyper::Client;
use tokio::runtime;
type Result<T> = std::result::Result<T, Box<dyn std::error::Error + Send + Sync>>;
fn main() {
let rt = runtime::Builder::new()
.threaded_scheduler()
.core_threads(1)
.enable_all()
.build()
.unwrap();
// spawn a request and then drop the runtime immediately
rt.spawn(fetch_url());
}
async fn fetch_url() -> Result<()> {
let url: hyper::Uri = "http://example.com".parse()?;
let client = Client::builder().build_http::<hyper::Body>();
let res = client.get(url).await?;
println!("Response: {}", res.status());
Ok(())
}
```
This is *just* a "trait alias". It is automatically implemented for all
`Service<Uri>`s that have the required bounds. It's purpose being public
is to ease setting trait bounds outside of hyper. Therefore, it doesn't
have any exposed associated types, to prevent otherwise relying on any
super-traits that hyper requires.
Instead of returning a tuple `(impl AsyncRead + AsyncWrite, Connected)`,
this adds a new trait, `hyper::client::connect::Connection`, which
allows querying the connection type for a `Connected`.
BREAKING CHANGE: Connectors no longer return a tuple of
`(T, Connected)`, but a single `T: Connection`.
It is not possible to connect to an IPv4 address from an IPv6 address or
vice-versa so don't waste time trying. If no remote addresses match then a
"missing connect error" will now occur.
Closes#1903
BREAKING CHANGE: The `Resolve` trait is gone. All custom resolves should
implement `tower::Service` instead.
The error type of `HttpConnector` has been changed away from
`std::io::Error`.
The `Connect` trait is now essentially an alias for
`Service<Destination>`, with a blanket implementation as such, and is
sealed.
Closes#1902
BREAKING CHANGE: Any manual implementations of `Connect` must instead
implement `tower::Service<Destination>`.
This takes the same strategy as golang, where the timeout value is
divided equally between the candidate socket addresses.
If happy eyeballs is enabled, the division takes place "below" the
IPv4/IPv6 partitioning.
The `HttpConnector` and `AddrListener` types which make use of
`tokio::tcp` have been made their own optional feature. This allows
using them without requiring the *full* tokio runtime.
