perf: hoist shell normalisation and cache notification regex objects#39
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shanselman merged 1 commit intomasterfrom Mar 17, 2026
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ExecApprovalPolicy.Evaluate: normalizedShell was allocated inside the foreach loop for every rule that carries a shell filter. Moving the computation before the loop avoids the repeated allocation on the hot command-evaluation path. NotificationCategorizer.MatchesRule: the static Regex.IsMatch overload that accepts a matchTimeout bypasses .NET's internal regex cache, so a new Regex object was compiled on every incoming notification for each regex-pattern user rule. Replace with a ConcurrentDictionary<string, Regex?> that caches compiled instances (constructed with the 100 ms timeout so ReDoS protection is preserved). Subsequent notifications reuse the same compiled automaton.
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Two targeted performance improvements to hot-path code in OpenClaw.Shared, originally identified by Repo Assist (#34).
1. ExecApprovalPolicy.Evaluate — hoist shell normalisation
normalizedShellwas allocated inside the foreach loop once per rule with a shell filter. Moved before the loop — one allocation instead of N.2. NotificationCategorizer.MatchesRule — cache compiled Regex instances
The
Regex.IsMatchoverload withmatchTimeoutbypasses .NET's internal static regex cache. Replaced with aConcurrentDictionary<string, Regex?>that caches compiled instances. ReDoS timeout (100ms) preserved. Invalid patterns stored as null soRegexParseExceptiononly thrown once.All 432 tests pass. No behaviour changes.
Closes #34