- Adds `Connected::negotiated_h2()` method to signal the connection must
use HTTP2. `Connect` implementations should set this if using ALPN.
If a connection to a host is detected to have been upgraded via ALPN,
any other oustanding connect futures will be canceled, and the waiting
requests will make use of the single HTTP2 connection.
The `http2_only` builder configuration still works the same, not
requiring ALPN at all, and always using only a single connection.
This introduces a `Resolve` trait to describe asynchronous DNS
resolution. The `HttpConnector` can be configured with a resolver,
allowing a user to still use all the functionality of the
`HttpConnector`, while customizing the DNS resolution.
To prevent a breaking change, the `HttpConnector` has its `Resolve`
generic set by default to `GaiResolver`. This is same as the existing
resolver, which uses `getaddrinfo` inside a thread pool.
Closes#1517
- Adds `client::connect::Connected::extra()`, which allows connectors to
specify arbitrary custom information about a connected transport.
If a connector provides this extra value, it will be set in the
`Response` extensions.
Closes#1402
Until this commit, servers have required that `Service` and their
`Future` to be `Send`, since the server needs to spawn some internal
tasks to an executor, and by default, that is `tokio::spawn`, which
could be spawning to a threadpool. This was true even if the user were
certain there was no threadpool involved, and was instead using a
different single-threaded runtime, like
`tokio::runtime::current_thread`.
This changes makes all the server pieces generic over an `E`, which is
essentially `Executor<PrivateTypes<Server::Future>>`. There's a new set
of internal traits, `H2Exec` and `NewSvcExec`, which allow for the type
signature to only show the generics that the user is providing. The
traits cannot be implemented explicitly, but there are blanket
implementations for `E: Executor<SpecificType>`. If the user provides
their own executor, it simply needs to have a generic `impl<F>
Executor<F> for MyExec`. That impl can have bounds deciding whether to
require `F: Send`. If the executor does require `Send`, and the
`Service` futures are `!Send`, there will be compiler errors.
To prevent a breaking change, all the types that gained the `E` generic
have a default type set, which is the original `tokio::spawn` executor.
rustc issue: https://github.com/rust-lang/rust/issues/55105
Steps to reproduce:
```
rustup target add armv7-linux-androideabi
RUSTFLAGS="-Ctarget-feature=+neon" cargo build --target armv7-linux-androideabi --release
```
Output without this change:
```
Compiling hyper v0.12.11 (/home/simon/projects/servo-deps/hyper)
LLVM ERROR: ran out of registers during register allocation
error: Could not compile `hyper`.
```
