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a52386e837
nushell/crates/nu_plugin_formats
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Stefan Holderbach a52386e837
Box ShellError in Value::Error (#8375) 
# Description

Our `ShellError` at the moment has a `std::mem::size_of<ShellError>` of
136 bytes (on AMD64). As a result `Value` directly storing the struct
also required 136 bytes (thanks to alignment requirements).

This change stores the `Value::Error` `ShellError` on the heap.

Pro:
- Value now needs just 80 bytes
- Should be 1 cacheline less (still at least 2 cachelines)

Con:
- More small heap allocations when dealing with `Value::Error`
  - More heap fragmentation
  - Potential for additional required memcopies

# Further code changes

Includes a small refactor of `try` due to a type mismatch in its large
match.

# User-Facing Changes

None for regular users.

Plugin authors may have to update their matches on `Value` if they use
`nu-protocol`

Needs benchmarking to see if there is a benefit in real world workloads.
**Update** small improvements in runtime for workloads with high volume
of values. Significant reduction in maximum resident set size, when many
values are held in memory.

# Tests + Formatting
2023-03-12 09:57:27 +01:00
..
src Box ShellError in Value::Error (#8375) 2023-03-12 09:57:27 +01:00
Cargo.toml Update to 0.76.1 version for development (#8161) 2023-02-21 23:21:39 +00:00
README.md Move some from xxx commands to plugin (#7942) 2023-02-13 12:42:08 +00:00

README.md

nu_plugin_formats

A nushell plugin to convert data to nushell tables.

support commands:

  1. from eml - original ported from nushell core.
  2. from ics - original ported from nushell core.
  3. from ini - original ported from nushell core.
  4. from vcf - original ported from nushell core.

Prerequisite

nushell, It's a nushell plugin, so you need it.

Usage

  1. compile the binary: cargo build
  2. register plugin(assume it's compiled in ./target/debug/):
register ./target/debug/nu_plugin_formats