Add LRU regex cache (#7587)

Closes #7572 by adding a cache for compiled regexes of type
`Arc<Mutex<LruCache<String, Regex>>>` to `EngineState` .

The cache is limited to 100 entries (limit chosen arbitrarily) and
evicts least-recently-used items first.

This PR makes a noticeable difference when using regexes for
`color_config`, e.g.:
```bash
#first set string formatting in config.nu like:
string: { if $in =~ '^#\w{6}$' { $in } else { 'white' } }`

# then try displaying and exploring a table with many strings
# this is instant after the PR, but takes hundreds of milliseconds before
['#ff0033', '#0025ee', '#0087aa', 'string', '#4101ff', '#ff0033', '#0025ee', '#0087aa', 'string', '#6103ff', '#ff0033', '#0025ee', '#0087aa', 'string', '#6103ff', '#ff0033', '#0025ee', '#0087aa', 'string', '#6103ff', '#ff0033', '#0025ee', '#0087aa', 'string', '#6103ff','#ff0033', '#0025ee', '#0087aa', 'string', '#6103ff','#ff0033', '#0025ee', '#0087aa', 'string', '#6103ff','#ff0033', '#0025ee', '#0087aa', 'string', '#6103ff','#ff0033', '#0025ee', '#0087aa', 'string', '#6103ff','#ff0033', '#0025ee', '#0087aa', 'string', '#6103ff']
```

## New dependency (`lru`)
This uses [the popular `lru` crate](https://lib.rs/crates/lru). The new
dependency adds 19.8KB to a Linux release build of Nushell. I think this
is OK, especially since the crate can be useful elsewhere in Nu.
This commit is contained in:
Reilly Wood
2022-12-23 14:30:04 -08:00
committed by GitHub
parent 3be7996e79
commit a43e66ef92
5 changed files with 58 additions and 14 deletions

View File

@ -402,9 +402,11 @@ pub fn eval_expression(
Comparison::NotEqual => lhs.ne(op_span, &rhs, expr.span),
Comparison::In => lhs.r#in(op_span, &rhs, expr.span),
Comparison::NotIn => lhs.not_in(op_span, &rhs, expr.span),
Comparison::RegexMatch => lhs.regex_match(op_span, &rhs, false, expr.span),
Comparison::RegexMatch => {
lhs.regex_match(engine_state, op_span, &rhs, false, expr.span)
}
Comparison::NotRegexMatch => {
lhs.regex_match(op_span, &rhs, true, expr.span)
lhs.regex_match(engine_state, op_span, &rhs, true, expr.span)
}
Comparison::StartsWith => lhs.starts_with(op_span, &rhs, expr.span),
Comparison::EndsWith => lhs.ends_with(op_span, &rhs, expr.span),