# Description
This changes the serialization of custom values within the plugin
protocol to use MessagePack instead of bincode, removing the dependency
on bincode entirely.
Bincode does not seem to be very maintained anymore, and the externally
tagged enum representation doesn't seem to always work now even though
it should. Since we use MessagePack already anyway for the plugin
protocol, this seems like an obvious choice. This uses the unnamed
variant of the serialization rather than the named variant, which is
what the plugin protocol in general uses. The unnamed variant does not
include field names, which aren't really required here, so this should
give us something that's more or less as efficient as bincode is.
Should fix#13743.
# User-Facing Changes
- Will need to recompile plugins (but always do anyway)
- Doesn't technically break the plugin protocol (custom value data is a
black box / plugin implementation specific), but breaks compatibility
between `nu-plugin-engine` and `nu-plugin` so they do need to both be
updated to match.
# Tests + Formatting
All tests pass.
# After Submitting
- [ ] release notes
# Description
This breaks `nu-plugin` up into four crates:
- `nu-plugin-protocol`: just the type definitions for the protocol, no
I/O. If someone wanted to wire up something more bare metal, maybe for
async I/O, they could use this.
- `nu-plugin-core`: the shared stuff between engine/plugin. Less stable
interface.
- `nu-plugin-engine`: everything required for the engine to talk to
plugins. Less stable interface.
- `nu-plugin`: everything required for the plugin to talk to the engine,
what plugin developers use. Should be the most stable interface.
No changes are made to the interface exposed by `nu-plugin` - it should
all still be there. Re-exports from `nu-plugin-protocol` or
`nu-plugin-core` are used as required. Plugins shouldn't ever have to
use those crates directly.
This should be somewhat faster to compile as `nu-plugin-engine` and
`nu-plugin` can compile in parallel, and the engine doesn't need
`nu-plugin` and plugins don't need `nu-plugin-engine` (except for test
support), so that should reduce what needs to be compiled too.
The only significant change here other than splitting stuff up was to
break the `source` out of `PluginCustomValue` and create a new
`PluginCustomValueWithSource` type that contains that instead. One bonus
of that is we get rid of the option and it's now more type-safe, but it
also means that the logic for that stuff (actually running the plugin
for custom value ops) can live entirely within the `nu-plugin-engine`
crate.
# User-Facing Changes
- New crates.
- Added `local-socket` feature for `nu` to try to make it possible to
compile without that support if needed.
# Tests + Formatting
- 🟢 `toolkit fmt`
- 🟢 `toolkit clippy`
- 🟢 `toolkit test`
- 🟢 `toolkit test stdlib`
