perf: cache allowlist and account-id normalization

src/routing/account-id.ts

@@ -6,6 +6,10 @@ const VALID_ID_RE = /^[a-z0-9][a-z0-9_-]{0,63}$/i;
 const INVALID_CHARS_RE = /[^a-z0-9_-]+/g;
 const LEADING_DASH_RE = /^-+/;
 const TRAILING_DASH_RE = /-+$/;
+const ACCOUNT_ID_CACHE_MAX = 512;
+
+const normalizeAccountIdCache = new Map<string, string>();
+const normalizeOptionalAccountIdCache = new Map<string, string | undefined>();
 
 function canonicalizeAccountId(value: string): string {
   if (VALID_ID_RE.test(value)) {
@@ -32,7 +36,13 @@ export function normalizeAccountId(value: string | undefined | null): string {
   if (!trimmed) {
     return DEFAULT_ACCOUNT_ID;
   }
-  return normalizeCanonicalAccountId(trimmed) || DEFAULT_ACCOUNT_ID;
+  const cached = normalizeAccountIdCache.get(trimmed);
+  if (cached) {
+    return cached;
+  }
+  const normalized = normalizeCanonicalAccountId(trimmed) || DEFAULT_ACCOUNT_ID;
+  setNormalizeCache(normalizeAccountIdCache, trimmed, normalized);
+  return normalized;
 }
 
 export function normalizeOptionalAccountId(value: string | undefined | null): string | undefined {
@@ -40,5 +50,21 @@ export function normalizeOptionalAccountId(value: string | undefined | null): st
   if (!trimmed) {
     return undefined;
   }
-  return normalizeCanonicalAccountId(trimmed) || undefined;
+  if (normalizeOptionalAccountIdCache.has(trimmed)) {
+    return normalizeOptionalAccountIdCache.get(trimmed);
+  }
+  const normalized = normalizeCanonicalAccountId(trimmed) || undefined;
+  setNormalizeCache(normalizeOptionalAccountIdCache, trimmed, normalized);
+  return normalized;
+}
+
+function setNormalizeCache<T>(cache: Map<string, T>, key: string, value: T): void {
+  cache.set(key, value);
+  if (cache.size <= ACCOUNT_ID_CACHE_MAX) {
+    return;
+  }
+  const oldest = cache.keys().next();
+  if (!oldest.done) {
+    cache.delete(oldest.value);
+  }
 }