Closes#83
This PR aims to move all of Valence's networking code to the new
`valence_protocol` crate. Anything not specific to valence is going in
the new crate. It also redesigns the way packets are defined and makes a
huge number of small additions and improvements. It should be much
easier to see where code is supposed to go from now on.
`valence_protocol` is a new library which enables interactions with
Minecraft's protocol. It is completely decoupled from valence and can be
used to build new clients, servers, tools, etc.
There are two additions that will help with #5 especially:
- It is now easy to define new packets or modifications of existing
packets. Not all packets need to be bidirectional.
- The `CachedEncode` type has been created. This is used to safely cache
redundant calls to `Encode::encode`.
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 current approach to managing chunk data is misconceived. This new approach uses genuine paletted containers and does not suffer from complexities caused by caching. As a result, memory usage (according to htop) in the terrain example with render distance = 32 has gone from 785 megs to 137 megs. That's 17.4% of the memory it used to use. Terrain generation speed was not affected.
