This PR adds accessors to `client::Connection` and `server::Connection`
that return the send stream concurrency limit on that connection, as
negotiated by the remote peer. This is part of issue #512.
I think we probably ought to expose similar accessors for other
settings, but I thought it was better to add each one in a separate,
focused PR.
Signed-off-by: Eliza Weisman <eliza@buoyant.io>
The `compare_and_swap` method on atomics is now deprecated in favor
of `compare_exchange`.
Since the author of #510 closed that PR, this is just #510 with rustfmt run.
I also removed an unnecessary trailing semicolon that the latest rust
compiler now complains about.
Signed-off-by: Eliza Weisman <eliza@buoyant.io>
Co-authored-by: Kornel <kornel@cloudflare.com>
Tokio's AsyncWrite trait once again has support for vectored writes in
Tokio 0.3.4 (see tokio-rs/tokio#3149.
This branch re-enables vectored writes in h2.
This change doesn't make all that big of a performance improvement in
Hyper's HTTP/2 benchmarks, but they use a BytesMut as the buffer.
With a buffer that turns into more IO vectors in bytes_vectored, there
might be a more noticeable performance improvement.
I spent a bit trying to refactor the flush logic to coalesce into fewer
writev calls with more buffers, but the current implementation seems
like about the best we're going to get without a bigger refactor. It's
basically the same as what h2 did previously, so it's probably fine.
We've adopted `tracing` for diagnostics, but currently, it is just being
used as a drop-in replacement for the `log` crate. Ideally, we would
want to start emitting more structured diagnostics, using `tracing`'s
`Span`s and structured key-value fields.
A lot of the logging in `h2` is already written in a style that imitates
the formatting of structured key-value logs, but as textual log
messages. Migrating the logs to structured `tracing` events therefore is
pretty easy to do. I've also started adding spans, mostly in the read
path.
Finally, I've updated the tests to use `tracing` rather than
`env_logger`. The tracing setup happens in a macro, so that a span for
each test with the test's name can be generated and entered. This will
make the test output easier to read if multiple tests are run
concurrently with `--nocapture`.
Signed-off-by: Eliza Weisman <eliza@buoyant.io>
`Streams.inner.ref` doesn't need to be incremented if we don't
return an `OpaqueStreamRef`.
This prevented the bug in `send_push_promise` from appearing
in the tests.
A connection can never have more than u32::MAX >> 1 streams, so we'll
never store more than that many in the store slab. Define the
`SlabIndex` as a `u32` to reduce the number of bytes moved around.
