The main changes are:
* The entry point is how `Http`, the implementation of `ServerProto`.
This type has a `new` constructor as well as builder methods to
configure it.
* A high-level entry point of `Http::bind` was added which returns a
`Server`. Binding a protocol to a port requires a socket address
(where to bind) as well as the instance of `NewService`. Internally
this creates a core and a TCP listener.
* The returned `Server` has a few methods to learn about itself, e.g.
`local_addr` and `handle`, but mainly has two methods: `run` and
`run_until`.
* The `Server::run` entry point will execute a server infinitely, never
having it exit.
* The `Server::run_until` method is intended as a graceful shutdown
mechanism. When the provided future resolves the server stops
accepting connections immediately and then waits for a fixed period of
time for all active connections to get torn down, after which the
whole server is torn down anyway.
* Finally a `Http::bind_connection` method exists as a low-level entry
point to spawning a server connection. This is used by `Server::run`
as is intended for external use in other event loops if necessary or
otherwise low-level needs.
BREAKING CHANGE: `Server` is no longer the pimary entry point. Instead,
an `Http` type is created and then either `bind` to receiver a `Server`,
or it can be passed to other Tokio things.
This allows us to improve the performance. For now, a Cow is used
internally, so clients can set the host to a static value and no longer
need copies.
Later, we can change it to also possibly have a MemSlice.
BREAKING CHANGE: The fields of the `Host` header are no longer
available. Use the getter methods instead.
This removes the cookie crate, since it has an optional dependency on
openssl, which can cause massive breakage if toggled on. Instead, the
`Cookie` and `SetCookie` headers now just use a `String`. Anyone can
create any typed header, so it is easy to plug in different
implementations.
BREAKING CHANGE: The `Cookie` and `SetCookie` headers no longer use the
cookie crate. New headers can be written for any header, or the ones
provided in hyper can be accessed as strings.
There are many changes involved with this, but let's just talk about
user-facing changes.
- Creating a `Client` and `Server` now needs a Tokio `Core` event loop
to attach to.
- `Request` and `Response` both no longer implement the
`std::io::{Read,Write}` traits, but instead represent their bodies as a
`futures::Stream` of items, where each item is a `Chunk`.
- The `Client.request` method now takes a `Request`, instead of being
used as a builder, and returns a `Future` that resolves to `Response`.
- The `Handler` trait for servers is no more, and instead the Tokio
`Service` trait is used. This allows interoperability with generic
middleware.
BREAKING CHANGE: A big sweeping set of breaking changes.
Support for strict-origin and strict-origin-when-cross-origin in referer
policy required for imporving network security. This commit will attempt
to add missing pieces of referrer policy.
This should fix some busy looping when using OpenSSL. For example, if
the transport was blocked on a read, it wasn't surfaced to the
`http::Conn` and so the wrong interest was registered with the event
loop. Registering for the wrong interest triggered calls to
`http::Conn::ready()` which were unable to make progress.
We encountered some issues where the `Conn::ready()` would busy loop on
reads. Previously, the `ConnInner::can_read_more()` would not consider
whether the previous read got a WouldBlock error, and it didn't consider
whether the transport was blocked. Accounting for this additional state
fixes the busy loop problem.
The previous keep-alive strategy was to cycle connections in a
round-robin style. However, that will always keep more connections
around than are needed. This new strategy will allow extra connections
to expire when only a few are needed. This is accomplished by prefering
to reuse a connection that was just released to the pool over one that
has been there for a long time.
It's possible that a connection will be closed and the only way to find
out is by doing a read. The keep-alive state (State::Init + Next_::Wait)
now tries to read on readable. In the case of EOF, it returns state
closed. If bytes are actually available, it's a connection error, and
the connection is closed. Otherwise, it's just a spurious wakeup.
Not handling this was an issue for keep-alive connections because
requests would get assigned to a closed connection and then immediately
error. Handling the HUP event makes this situation much less likely. It
is still possible however; consider the situation where a HUP arrives
while the event loop is busy processing new requests to add. The
connection is disconnected, but the HUP hasn't been processed, and a
request could be assigned to it. This case is, however, unlikely.
We've been seeing a strange number of timeouts in our benchmarking.
Handling spurious timeouts as in this patch seems to fix it!
Note that managing the `timeout_start` needs to be done carefully. If
the current time is provided in the wrong place, it's possible requests
would never timeout.
I've had a couple of instances during stress testing now where
Conn::ready would overflow its stack due to recursing on itself. This
moves subsequent calls to ready() into a loop outside the function.
When loading up a client suddenly with thousands of connections, the
default DNS worker count of four cannot keep up and many requests
timeout as a result. Most people don't need a large pool, so making this
configurable is a natural choice.
We observed an issue where connection were not ever entering the
keep-alive state due to a bug with `State::update`. The issue is
resolved with resetting the write state to KeepAlive when it arrives as
KeepAlive. Otherwise, it would be marked incorrectly as Closed.
The `trace!` lines in here are useful for debugging keep-alive issues so
I've left them in.
In the scenario where a request is started on the `Client`, the client
has a full slab, and sockets for a *different* domain are idling in
keep-alive, the new request would previously cause the client to panic!.
This patch adds a `spawn_error` handler which attempts to evict an idle
connection to make space for the new request. If space cannot be made,
the error handler is run (passed `Error::Full`) and the `Handler` is
dropped.
This is a breaking change because of the new variant of `Error`.
Some inefficient use of `Vec` in the client was replaced with `VecDeque`
to support push/pop from either end.
Closes#896Closes#897
BREAKING CHANGE: `RequestUri::AbsolutePath` variant is changed to a struct variant. Consider using `req.path()` or `req.query()` to get the relevant slice.
Closes#891
BREAKING CHANGE: `Headers.remove()` used to return a `bool`,
it now returns `Option<H>`. To determine if a a header exists,
switch to `Headers.has()`.
