nushell/crates/nu-explore/src
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
..
commands Use variable names directly in the format strings (#7906) 2023-01-29 19:37:54 -06:00
nu_common Box ShellError in Value::Error (#8375) 2023-03-12 09:57:27 +01:00
pager Use variable names directly in the format strings (#7906) 2023-01-29 19:37:54 -06:00
registry fix some typos (#7773) 2023-01-16 12:43:46 +01:00
views Use variable names directly in the format strings (#7906) 2023-01-29 19:37:54 -06:00
lib.rs Reduce again the number of match calls (#7815) 2023-01-24 12:23:42 +01:00