The `tracing` crate seems to be the go-to
logging/profiling/instrumentation solution nowadays. Perhaps in the
future we could use `tracing` for profiling instead of (or in addition
to) the `perf`-based `cargo flamegraph` command. This would sidestep the
issue of `rayon` polluting the output. I conducted an initial experiment
by adding some more spans but wasn't very happy with the result.
Log messages have also been improved. There is some additional context
and events are raised when clients are added/removed from the server.
Closes#82Closes#43Closes#64
# Changes and Improvements
- Packet encoding/decoding happens within `Client` instead of being sent
over a channel first. This is better for performance and lays the
groundwork for #83.
- Reduce the amount of copying necessary by leveraging the `bytes` crate
and recent changes to `EncodePacket`. Performance is noticeably improved
with maximum players in the `rust-mc-bot` test going from 750 to 1050.
- Packet encoding/decoding code is decoupled from IO. This is easier to
understand and more suitable for a future protocol lib.
- Precise control over the number of bytes that are buffered for
sending/receiving. This is important for limiting maximum memory usage
correctly.
- "packet controllers" are introduced, which are convenient structures
for managing packet IO before and during the play state.
- `byte_channel` module is created to help implement the
`PlayPacketController`. This is essentially a channel of bytes
implemented with an `Arc<Mutex<BytesMut>>`.
- Error handling in the update procedure for clients was improved using
`anyhow::Result<()>` to exit as early as possible. The `client` module
is a bit cleaner as a result.
- The `LoginPlay` packet is always sent before all other play packets.
We no longer have to worry about the behavior of packets sent before
that packet. Most packet deferring performed currently can be
eliminated.
- The packet_inspector was rewritten in response to the above changes.
- Timeouts on IO operations behave better.
# Known Issues
- The packet_inspector now re-encodes packets rather than just decoding
them. This will cause problems when trying to use it with the vanilla
server because there are missing clientbound packets and other issues.
This will be fixed when the protocol module is moved to a separate
crate.
The texture payload (skin + cape URL) that we get from the auth server
needs to stay intact so the signature is not invalidated. However, skins
still aren't loading. Not sure what's up with that.
