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Merged
jqnatividad merged 1 commit into from
Oct 3, 2026
Merged

perf(parse): give each thread its own regex cache pool #13

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121 changes: 68 additions & 53 deletions src/datetime.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -3,17 +3,31 @@ use crate::timezone;
use anyhow::{Result, anyhow};
use chrono::format::{Item, ParseResult, Parsed, parse as parse_items};
use chrono::prelude::*;
use regex::Regex;

/// Compiles a regex literal once per process and hands each thread its own
/// clone, as a `&'static LocalKey<Regex>` used via `.with(|re| ...)`.
///
/// A shared `Regex` gives only its first-using thread the lock-free cache fast
/// path; every other thread takes a mutex-protected cache stack. Under a
/// parallel caller (e.g. `qsv stats --infer-dates` on 16 threads) that
/// contention nearly doubled the CPU cost of date parsing. `Regex::clone`
/// shares the compiled program but builds a fresh cache pool, so each thread
/// becomes the owner of its own pool. Thread-local (not leaked) so a long-lived
/// process that churns threads doesn't accumulate caches.
macro_rules! regex {
($re:literal $(,)?) => {{
static RE: std::sync::OnceLock<regex::Regex> = std::sync::OnceLock::new();
RE.get_or_init(|| {
regex::RegexBuilder::new($re)
.unicode(false)
.build()
.expect("invalid regex literal")
})
thread_local! {
static TL: regex::Regex = RE
.get_or_init(|| {
regex::RegexBuilder::new($re)
.unicode(false)
.build()
.expect("invalid regex literal")
})
.clone();
}
&TL
}};
}

Expand Down Expand Up @@ -433,12 +447,12 @@ where

#[inline]
fn ymd_family(&self, input: &str) -> Option<Result<DateTime<Utc>>> {
let re: &Regex = regex! {
let re = regex! {
r"^\d{4}-\d{2}"

};

if !re.is_match(input) {
if !re.with(|r| r.is_match(input)) {
return None;
}
self.rfc3339(input)
Expand All @@ -450,11 +464,11 @@ where

#[inline]
fn month_mdy_family(&self, input: &str) -> Option<Result<DateTime<Utc>>> {
let re: &Regex = regex! {
let re = regex! {
r"^[a-zA-Z]{3,9}\.?\s+\d{1,2}"
};

if !re.is_match(input) {
if !re.with(|r| r.is_match(input)) {
return None;
}
self.month_mdy_hms(input)
Expand All @@ -464,20 +478,20 @@ where

#[inline]
fn month_dmy_family(&self, input: &str) -> Option<Result<DateTime<Utc>>> {
let re: &Regex = regex! {r"^\d{1,2}\s+[a-zA-Z]{3,9}"
let re = regex! {r"^\d{1,2}\s+[a-zA-Z]{3,9}"
};

if !re.is_match(input) {
if !re.with(|r| r.is_match(input)) {
return None;
}
self.month_dmy_hms(input).or_else(|| self.month_dmy(input))
}

#[inline]
fn slash_mdy_family(&self, input: &str) -> Option<Result<DateTime<Utc>>> {
let re: &Regex = regex! {r"^\d{1,2}/\d{1,2}"
let re = regex! {r"^\d{1,2}/\d{1,2}"
};
if !re.is_match(input) {
if !re.with(|r| r.is_match(input)) {
return None;
}
if self.prefer_dmy {
Expand All @@ -495,8 +509,8 @@ where

#[inline]
fn slash_ymd_family(&self, input: &str) -> Option<Result<DateTime<Utc>>> {
let re: &Regex = regex! {r"^[0-9]{4}/[0-9]{1,2}"};
if !re.is_match(input) {
let re = regex! {r"^[0-9]{4}/[0-9]{1,2}"};
if !re.with(|r| r.is_match(input)) {
return None;
}
self.slash_ymd_hms(input).or_else(|| self.slash_ymd(input))
Expand Down Expand Up @@ -582,11 +596,11 @@ where
// - 2012-03-19 10:11:59.318 PM
#[inline]
fn ymd_hms(&self, input: &str) -> Option<Result<DateTime<Utc>>> {
let re: &Regex = regex! {
let re = regex! {
r"^\d{4}-\d{2}-\d{2}[T\s]+\d{2}:\d{2}(?::\d{2})?(?:\.\d{1,9})?\s*(?:am|pm|AM|PM)?$"

};
if !re.is_match(input) {
if !re.with(|r| r.is_match(input)) {
return None;
}

Expand Down Expand Up @@ -635,17 +649,17 @@ where
// tz group, which keeps the regex engine off the capture-tracking path.
// See `tz_suffix` — on failure this falls through to the original
// capture-based match, so no input can change meaning.
let prefix: &Regex = regex! {r"^\d{4}-\d{2}-\d{2}\s+\d{2}:\d{2}(?::\d{2})?(?:\.\d{1,9})?"};
let prefix = regex! {r"^\d{4}-\d{2}-\d{2}\s+\d{2}:\d{2}(?::\d{2})?(?:\.\d{1,9})?"};
let fast_tz = prefix
.find(input)
.with(|r| r.find(input))
.and_then(|m| tz_suffix(input, m.end(), false));

let re: &Regex = regex! {
let re = regex! {
r"^\d{4}-\d{2}-\d{2}\s+\d{2}:\d{2}(?::\d{2})?(?:\.\d{1,9})?(?P<tz>\s*[+-:a-zA-Z0-9]{3,6})$"
};

if let Some(tz) = fast_tz.or_else(|| {
re.captures(input)
re.with(|r| r.captures(input))
.and_then(|caps| caps.name("tz").map(|m| m.as_str().trim()))
}) {
let parse_from_str = Self::naive_dt_from_items;
Expand All @@ -667,10 +681,10 @@ where
// - 2021-02-21
#[inline]
fn ymd(&self, input: &str) -> Option<Result<DateTime<Utc>>> {
let re: &Regex = regex! {r"^\d{4}-\d{2}-\d{2}$"
let re = regex! {r"^\d{4}-\d{2}-\d{2}$"
};

if !re.is_match(input) {
if !re.with(|r| r.is_match(input)) {
return None;
}
let now = Utc::now()
Expand All @@ -695,9 +709,9 @@ where
if input.len() <= 10 {
return None;
}
let re: &Regex = regex! {r"^\d{4}-\d{2}-\d{2}(?P<tz>\s*[+-:a-zA-Z0-9]{3,6})$"
let re = regex! {r"^\d{4}-\d{2}-\d{2}(?P<tz>\s*[+-:a-zA-Z0-9]{3,6})$"
};
if let Some(caps) = re.captures(input)
if let Some(caps) = re.with(|r| r.captures(input))
&& let Some(matched_tz) = caps.name("tz")
{
return match timezone::parse(matched_tz.as_str().trim()) {
Expand All @@ -723,9 +737,9 @@ where
// - 2021-Feb-21
#[inline]
fn month_ymd(&self, input: &str) -> Option<Result<DateTime<Utc>>> {
let re: &Regex = regex! {r"^\d{4}-\w{3,9}-\d{2}$"
let re = regex! {r"^\d{4}-\w{3,9}-\d{2}$"
};
if !re.is_match(input) {
if !re.with(|r| r.is_match(input)) {
return None;
}

Expand All @@ -748,10 +762,10 @@ where
// - September 17, 2012, 10:10:09
#[inline]
fn month_mdy_hms(&self, input: &str) -> Option<Result<DateTime<Utc>>> {
let re: &Regex = regex! {
let re = regex! {
r"^[a-zA-Z]{3,9}\.?\s+\d{1,2},\s+\d{2,4},?\s+\d{1,2}:\d{2}(?::\d{2})?\s*(?:am|pm|AM|PM)?$"
};
if !re.is_match(input) {
if !re.with(|r| r.is_match(input)) {
return None;
}

Expand Down Expand Up @@ -811,18 +825,18 @@ where
// group requires whitespace (`\s+`), but the prefix's own trailing
// `\s*` may already have consumed it, so `tz_suffix` is told to accept
// the separator on either side of the boundary.
let prefix: &Regex = regex! {
let prefix = regex! {
r"^[a-zA-Z]{3,9}\s+\d{1,2},?\s+\d{4}\s*,?(?:at)?\s+\d{2}:\d{2}(?::\d{2})?\s*(?:am|pm|AM|PM)?"
};
let fast_tz = prefix
.find(input)
.with(|r| r.find(input))
.and_then(|m| tz_suffix(input, m.end(), true));

let re: &Regex = regex! {
let re = regex! {
r"^[a-zA-Z]{3,9}\s+\d{1,2},?\s+\d{4}\s*,?(?:at)?\s+\d{2}:\d{2}(?::\d{2})?\s*(?:am|pm|AM|PM)?(?P<tz>\s+[+-:a-zA-Z0-9]{3,6})$",
};
if let Some(tz) = fast_tz.or_else(|| {
re.captures(input)
re.with(|r| r.captures(input))
.and_then(|caps| caps.name("tz").map(|m| m.as_str().trim()))
}) {
let parse_from_str = Self::naive_dt_from_items;
Expand Down Expand Up @@ -865,9 +879,9 @@ where
// - October 7, 1970
#[inline]
fn month_mdy(&self, input: &str) -> Option<Result<DateTime<Utc>>> {
let re: &Regex = regex! {r"^[a-zA-Z]{3,9}\.?\s+\d{1,2},\s+\d{2,4}$"
let re = regex! {r"^[a-zA-Z]{3,9}\.?\s+\d{1,2},\s+\d{2,4}$"
};
if !re.is_match(input) {
if !re.with(|r| r.is_match(input)) {
return None;
}

Expand Down Expand Up @@ -906,10 +920,10 @@ where
if !input.as_bytes().contains(&b':') {
return None;
}
let re: &Regex = regex! {
let re = regex! {
r"^\d{1,2}\s+[a-zA-Z]{3,9}\s+\d{2,4},?\s+\d{1,2}:[0-9]{2}(?::[0-9]{2})?(?:\.[0-9]{1,9})?$"
};
if !re.is_match(input) {
if !re.with(|r| r.is_match(input)) {
return None;
}

Expand Down Expand Up @@ -945,9 +959,9 @@ where
// - 1 July 2013
#[inline]
fn month_dmy(&self, input: &str) -> Option<Result<DateTime<Utc>>> {
let re: &Regex = regex! {r"^\d{1,2}\s+[a-zA-Z]{3,9}\s+\d{2,4}$"
let re = regex! {r"^\d{1,2}\s+[a-zA-Z]{3,9}\s+\d{2,4}$"
};
if !re.is_match(input) {
if !re.with(|r| r.is_match(input)) {
return None;
}

Expand Down Expand Up @@ -992,10 +1006,10 @@ where
// - 03/19/2012 10:11:59.318 PM
#[inline]
fn slash_mdy_hms(&self, input: &str) -> Option<Result<DateTime<Utc>>> {
let re: &Regex = regex! {
let re = regex! {
r"^\d{1,2}/\d{1,2}/\d{2,4}\s+\d{1,2}:\d{2}(?::\d{2})?(?:\.\d{1,9})?\s*(?:am|pm|AM|PM)?$"
};
if !re.is_match(input) {
if !re.with(|r| r.is_match(input)) {
return None;
}

Expand Down Expand Up @@ -1044,10 +1058,10 @@ where
// - 19/03/2012 10:11:59.318 PM
#[inline]
fn slash_dmy_hms(&self, input: &str) -> Option<Result<DateTime<Utc>>> {
let re: &Regex = regex! {
let re = regex! {
r"^\d{1,2}/\d{1,2}/\d{2,4}\s+\d{1,2}:\d{2}(?::\d{2})?(?:\.\d{1,9})?\s*(?:am|pm|AM|PM)?$"
};
if !re.is_match(input) {
if !re.with(|r| r.is_match(input)) {
return None;
}

Expand Down Expand Up @@ -1085,9 +1099,9 @@ where
// - 8/1/71
#[inline]
fn slash_mdy(&self, input: &str) -> Option<Result<DateTime<Utc>>> {
let re: &Regex = regex! {r"^\d{1,2}/\d{1,2}/\d{2,4}$"
let re = regex! {r"^\d{1,2}/\d{1,2}/\d{2,4}$"
};
if !re.is_match(input) {
if !re.with(|r| r.is_match(input)) {
return None;
}

Expand Down Expand Up @@ -1115,9 +1129,9 @@ where
// - 1/8/71
#[inline]
fn slash_dmy(&self, input: &str) -> Option<Result<DateTime<Utc>>> {
let re: &Regex = regex! {r"^[0-9]{1,2}/[0-9]{1,2}/[0-9]{2,4}$"
let re = regex! {r"^[0-9]{1,2}/[0-9]{1,2}/[0-9]{2,4}$"
};
if !re.is_match(input) {
if !re.with(|r| r.is_match(input)) {
return None;
}

Expand Down Expand Up @@ -1148,10 +1162,10 @@ where
// - 2012/03/19 10:11:59.318 PM
#[inline]
fn slash_ymd_hms(&self, input: &str) -> Option<Result<DateTime<Utc>>> {
let re: &Regex = regex! {
let re = regex! {
r"^[0-9]{4}/[0-9]{1,2}/[0-9]{1,2}\s+[0-9]{1,2}:[0-9]{2}(?::[0-9]{2})?(?:\.[0-9]{1,9})?\s*(?:am|pm|AM|PM)?$"
};
if !re.is_match(input) {
if !re.with(|r| r.is_match(input)) {
return None;
}

Expand All @@ -1173,9 +1187,9 @@ where
// - 2014/03/31
#[inline]
fn slash_ymd(&self, input: &str) -> Option<Result<DateTime<Utc>>> {
let re: &Regex = regex! {r"^[0-9]{4}/[0-9]{1,2}/[0-9]{1,2}$"
let re = regex! {r"^[0-9]{4}/[0-9]{1,2}/[0-9]{1,2}$"
};
if !re.is_match(input) {
if !re.with(|r| r.is_match(input)) {
return None;
}

Expand All @@ -1195,6 +1209,7 @@ where
#[cfg(test)]
mod tests {
use super::*;
use regex::Regex;

#[test]
fn unix_timestamp() {
Expand Down
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