nushell/crates/nu-protocol
Devyn Cairns 2ae9ad8676
Copy-on-write for record values (#12305)
# Description
This adds a `SharedCow` type as a transparent copy-on-write pointer that
clones to unique on mutate.

As an initial test, the `Record` within `Value::Record` is shared.

There are some pretty big wins for performance. I'll post benchmark
results in a comment. The biggest winner is nested access, as that would
have cloned the records for each cell path follow before and it doesn't
have to anymore.

The reusability of the `SharedCow` type is nice and I think it could be
used to clean up the previous work I did with `Arc` in `EngineState`.
It's meant to be a mostly transparent clone-on-write that just clones on
`.to_mut()` or `.into_owned()` if there are actually multiple
references, but avoids cloning if the reference is unique.

# User-Facing Changes
- `Value::Record` field is a different type (plugin authors)

# Tests + Formatting
- 🟢 `toolkit fmt`
- 🟢 `toolkit clippy`
- 🟢 `toolkit test`
- 🟢 `toolkit test stdlib`

# After Submitting
- [ ] use for `EngineState`
- [ ] use for `Value::List`
2024-04-14 01:42:03 +00:00
..
src Copy-on-write for record values (#12305) 2024-04-14 01:42:03 +00:00
tests Name the Value conversion functions more clearly (#11851) 2024-02-17 18:14:16 +00:00
Cargo.toml Bump version to 0.92.3 (#12476) 2024-04-12 08:00:43 -05:00
LICENSE Fix rest of license year ranges (#8727) 2023-04-04 09:03:29 +12:00
README.md Add nu-protocol 2021-09-02 13:29:43 +12:00

nu-protocol

The nu-protocol crate holds the definitions of structs/traits that are used throughout Nushell. This gives us one way to expose them to many other crates, as well as make these definitions available to each other, without causing mutually recursive dependencies.