This patch includes two new significant debug assertions:
* Assert stream counts are zero when the connection finalizes.
* Assert all stream state has been released when the connection is
dropped.
These two assertions were added in an effort to test the fix provided
by #261. In doing so, many related bugs have been discovered and fixed.
The details related to these bugs can be found in #273.
If graceful shutdown is initiated, a GOAWAY of the max stream ID - 1 is
sent, followed by a PING frame, to measure RTT. When the PING is ACKed,
the connection sends a new GOAWAY with the proper last processed stream
ID. From there, once all active streams have completely, the connection
will finally close.
When all Streams are dropped / finished, the Connection was held
open until the peer hangs up. Instead, the Connection should hang up
once it knows that nothing more will be sent.
To fix this, we notify the Connection when a stream is no longer
referenced. On the Connection poll(), we check that there are no
active, held, reset streams or any references to the Streams
and transition to sending a GOAWAY if that is case.
The specific behavior depends on if running as a client or server.
* Change send_reset to take &mut self.
While calling this function is the last thing that should be done with
the instance, the intent of the h2 library is not to be used directly by
users, but to be used as an implementation detail by other libraries.
Requiring `self` on `send_reset` is pretty annoying when calling the
function from inside a `Future` implementation. Also, all the other fns
on the type take `&mut self`.
* Remove the P: Peer generic from internals
* Split out `Respond` from `server::Stream`
This new type is used to send HTTP responses to the client as well as
reserve streams for push promises.
* Remove unused `Send` helper.
This could be brought back later when the API becomes stable.
* Unite `client` and `server` types
* Remove `B` generic from internal proto structs
This is a first step in removing the `B` generic from public API types
that do not strictly require it.
Currently, all public API types must be generic over `B` even if they do
not actually interact with the send data frame type. The first step in
removing this is to remove `B` as a generic on all internal types.
* Remove `Buffer<B>` from inner stream state
This is the next step in removing the `B` generic from all public API
types. The send buffer is the only type that requires `B`. It has now
been extracted from the rest of the stream state.
The strategy used in this PR requires an additional `Arc` and `Mutex`,
but this is not a fundamental requirement. The additional overhead can
be avoided with a little bit of unsafe code. However, this optimization
should not be made until it is proven that it is required.
* Remove `B` generic from `Body` + `ReleaseCapacity`
This commit actually removes the generic from these two public API
types. Also note, that removing the generic requires that `B: 'static`.
This is because there is no more generic on `Body` and `ReleaseCapacity`
and the compiler must be able to ensure that `B` outlives all `Body` and
`ReleaseCapacity` handles.
In practice, in an async world, passing a non 'static `B` is never going
to happen.
* Remove generic from `ResponseFuture`
This change also makes generic free types `Send`. The original strategy
of using a trait object meant that those handles could not be `Send`.
The solution was to avoid using the send buffer when canceling a stream.
This is done by transitioning the stream state to `Canceled`, a new
`Cause` variant.
* Simplify Send::send_reset
Now that implicit cancelation goes through a separate path, the
send_reset function can be simplified.
* Export types common to client & server at root
* Rename Stream -> SendStream, Body -> RecvStream
* Implement send_reset on server::Respond
This PR adds `max_concurrent_streams()` methods to the client and server `Builder`s to set the `max_concurrent_streams` setting. I've added unit tests to ensure the correct SETTINGS frame is sent.
Closes#106
Alter frame::Reason to a struct with a single u32 member.
Introduce Constants to the impl for existing Reasons. Change all usage
in the library and its tests to adopt this change,
using the new constants.
The Connection type is a `Future` that drives all of the IO of the
client connection.
The Client type is separate, and is used to send requests into the
connection.
This change adds a .rustfmt.toml that includes ALL supported settings,
12 of which we have overridden to attempt to cater to our own
proclivities.
rustfmt is checked in the rust-nightly CI job.
Previously, stream state was never released so that long-lived connections
leaked memory.
Now, stream states are reference-counted and freed from the stream slab
when complete. Locally reset streams are retained so that received frames
may be ignored.
This patch does a bunch of refactoring, mostly around error types, but it also
paves the way to allow `Codec` to be used standalone.
* `Codec` (and `FramedRead` / `FramedWrite`) is broken out into a codec module.
* An h2-codec crate is created that re-exports the frame and codec modules.
* New error types are introduced in the internals:
* `RecvError` represents errors caused by trying to receive a frame.
* `SendError` represents errors caused by trying to send a frame.
* `UserError` is an enum of potential errors caused by invalid usage
by the user of the lib.
* `ProtoError` is either a `Reason` or an `io::Error`. However it doesn't
specify connection or stream level.
* `h2::Error` is an opaque error type and is the only error type exposed
by the public API (used to be `ConnectionError`).
There are misc code changes to enable this as well. The biggest is a new "sink"
API for `Codec`. It provides buffer which queues up a frame followed by flush
which writes everything that is queued. This departs from the `Sink` trait in
order to provide more accurate error values. For example, buffer can never fail
(but it will panic if `poll_ready` is not called first).
Client::poll_ready ensures that the connection is ale to to initiate a new request stream to the remote server. When the server is at capacity, a task is stored to be notified when capacity is available.
