- Placed all cases of "unexpected bytes" errors into the
`UnexpectedMessage` variant.
- Placed all cases of "unexpected EOF" errors into the
`IncompleteMessage` variant. Description is now generic about
"connection closed before message completed", instead of mentioning
"request" or "response.
- Added `Error::is_incomplete_message()` accessor to help checking for
unexpected closures.
- Renamed some variants to be clearer when viewing the `Debug` format.
- Collected all "user" errors into an internal `User` enum, to prevent
forgetting to update the `is_user()` method.
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.
Automatically removes "connection" headers before sending over HTTP2.
These headers are illegal in HTTP2, and would otherwise cause errors.
Closes: #1551
