⚡ Bolt: [performance improvement] Optimize VPN state filtering with glob matching

.jules/bolt.md

@@ -8,3 +8,7 @@
 ## 2024-06-28 - Secure Native File Traversal Optimization
 **Learning:** Shelling out to `chown -R` via `os.system` incurs significant process spawning overhead and forces redundant directory traversals when modifying multiple permissions. However, directly replacing it with Python's native `os.chown` inside an `os.walk` loop introduces a critical Local Privilege Escalation (LPE) vulnerability, as `os.chown` follows symlinks by default whereas GNU `chown -R` does not.
 **Action:** When replacing `os.system("chown -R ...")` with native `os.walk` in Python scripts, always use `os.lchown` on files and directories to ensure symlinks are not maliciously followed, preserving the security guarantees of the original subprocess call while eliminating overhead.
+
+## 2024-05-16 - Regex Compilation Overhead in Tight Bash Loops
+**Learning:** Using bash regular expression matching (`=~`) inside a loop introduces significant overhead due to regex compilation on every evaluation compared to glob substring matching.
+**Action:** For optimal performance in tight Bash loops where simple substring matching is sufficient, prefer native glob matching (e.g., `[[ "|$LIST|" == *"|$item|"* ]]`) over regex evaluation (`=~`).

vpn-auto.sh

@@ -84,14 +84,17 @@ if [ -n "$US_SERVERS" ]; then
         state="${state%%#*}"
 
         # Check against exclusions
-        if [[ "$state" =~ ^($EXCLUDED_STATES)$ ]]; then
+        # ⚡ Bolt: Using native glob substring matching instead of bash regex '=~'
+        # avoids regex compilation overhead, speeding up processing in tight loops.
+        if [[ "|$EXCLUDED_STATES|" == *"|$state|"* ]]; then
             continue
         fi
 
         FILTERED_SERVERS+=("$server")
 
         # Check against favorites
-        if [[ "$state" =~ ^($FAVORED_STATES)$ ]]; then
+        # ⚡ Bolt: Using native glob substring matching instead of bash regex '=~'
+        if [[ "|$FAVORED_STATES|" == *"|$state|"* ]]; then
             FAVORED_SERVERS+=("$server")
         fi
     done