From e34c0ccf4ce3f39939826f357f8084bcd7cdf6da Mon Sep 17 00:00:00 2001
From: ProofOfConcept <poc@bcachefs.org>
Date: Tue, 3 Mar 2026 12:44:02 -0500
Subject: [PATCH] capnp_store: cache compiled regexes with OnceLock

parse_units and parse_marker_attrs were recompiling 4 regexes on
every call. Since they're called per-file during init, this was
measurable overhead. Use std::sync::OnceLock to compile once.
---
 src/capnp_store.rs | 21 +++++++++++++++------
 1 file changed, 15 insertions(+), 6 deletions(-)

diff --git a/src/capnp_store.rs b/src/capnp_store.rs
index 443862b..af1dc61 100644
--- a/src/capnp_store.rs
+++ b/src/capnp_store.rs
@@ -1606,11 +1606,18 @@ pub struct MemoryUnit {
 }
 
 pub fn parse_units(filename: &str, content: &str) -> Vec<MemoryUnit> {
-    let marker_re = Regex::new(
-        r"<!--\s*mem:\s*((?:id|links|tags|causes|state)\s*=\s*[^\s].*?)-->"
-    ).unwrap();
-    let source_re = Regex::new(r"<!--\s*source:\s*(.+?)\s*-->").unwrap();
-    let md_link_re = Regex::new(r"\[[^\]]*\]\(([^)]*\.md(?:#[^)]*)?)\)").unwrap();
+    use std::sync::OnceLock;
+
+    static MARKER_RE: OnceLock<Regex> = OnceLock::new();
+    static SOURCE_RE: OnceLock<Regex> = OnceLock::new();
+    static MD_LINK_RE: OnceLock<Regex> = OnceLock::new();
+
+    let marker_re = MARKER_RE.get_or_init(||
+        Regex::new(r"<!--\s*mem:\s*((?:id|links|tags|causes|state)\s*=\s*[^\s].*?)-->").unwrap());
+    let source_re = SOURCE_RE.get_or_init(||
+        Regex::new(r"<!--\s*source:\s*(.+?)\s*-->").unwrap());
+    let md_link_re = MD_LINK_RE.get_or_init(||
+        Regex::new(r"\[[^\]]*\]\(([^)]*\.md(?:#[^)]*)?)\)").unwrap());
 
     let markers: Vec<_> = marker_re.captures_iter(content)
         .map(|cap| {
@@ -1699,7 +1706,9 @@ pub fn parse_units(filename: &str, content: &str) -> Vec<MemoryUnit> {
 }
 
 fn parse_marker_attrs(attrs_str: &str) -> HashMap<String, String> {
-    let attr_re = Regex::new(r"(\w+)\s*=\s*(\S+)").unwrap();
+    use std::sync::OnceLock;
+    static ATTR_RE: OnceLock<Regex> = OnceLock::new();
+    let attr_re = ATTR_RE.get_or_init(|| Regex::new(r"(\w+)\s*=\s*(\S+)").unwrap());
     let mut attrs = HashMap::new();
     for cap in attr_re.captures_iter(attrs_str) {
         attrs.insert(cap[1].to_string(), cap[2].to_string());