nushell/crates/nu-command/src/viewers
JT 6872d2ac2a
Speed up tight loop benchmarks (#8609)
# Description

This does a few speedups for tight loops:
* Caches the DeclId for `table` so we don't look it up. This means users
can't easily replace the default one, we might want to talk about this
tradeoff. The lookup for finding `table` in a tight loop is currently
pretty heavy. Might be another way to speed this up.
* `table` no longer pre-calculates the width. Instead, it only
calculates the width when printing a table or record.
* Use more efficient way of collecting the block of each loop
* When printing output, only get the config when needed

Combined, this drops the runtime from a million loop tight iteration
from 1sec 8ms to 236ms.

# User-Facing Changes

_(List of all changes that impact the user experience here. This helps
us keep track of breaking changes.)_

# Tests + Formatting

Don't forget to add tests that cover your changes.

Make sure you've run and fixed any issues with these commands:

- `cargo fmt --all -- --check` to check standard code formatting (`cargo
fmt --all` applies these changes)
- `cargo clippy --workspace -- -D warnings -D clippy::unwrap_used -A
clippy::needless_collect` to check that you're using the standard code
style
- `cargo test --workspace` to check that all tests pass

> **Note**
> from `nushell` you can also use the `toolkit` as follows
> ```bash
> use toolkit.nu # or use an `env_change` hook to activate it
automatically
> toolkit check pr
> ```

# After Submitting

If your PR had any user-facing changes, update [the
documentation](https://github.com/nushell/nushell.github.io) after the
PR is merged, if necessary. This will help us keep the docs up to date.
2023-03-26 06:12:57 +13:00
..
explore.rs Box ShellError in Value::Error (#8375) 2023-03-12 09:57:27 +01:00
griddle.rs Optional members in cell paths: Attempt 2 (#8379) 2023-03-15 20:50:58 -07:00
icons.rs replace lazy_static with once_cell (#7502) 2022-12-17 10:30:04 -08:00
mod.rs [MVP][WIP] less like pager (#6984) 2022-12-01 09:32:10 -06:00
table.rs Speed up tight loop benchmarks (#8609) 2023-03-26 06:12:57 +13:00