Perf: use Bun.peek() to save a few ticks

Build/lib/cache-filesystem.ts

@@ -158,9 +158,21 @@ export class Cache {
     let value: T;
     if (cached == null) {
       console.log(picocolors.yellow('[cache] miss'), picocolors.gray(key), picocolors.gray(`ttl: ${TTL.humanReadable(ttl)}`));
-      value = await fn();
 
       const serializer = 'serializer' in opt ? opt.serializer : identity;
+
+      const promise = fn();
+      const peeked = Bun.peek(promise);
+
+      if (peeked === promise) {
+        return promise.then((value) => {
+          const serializer = 'serializer' in opt ? opt.serializer : identity;
+          this.set(key, serializer(value), ttl);
+          return value;
+        });
+      }
+
+      value = peeked as T;
       this.set(key, serializer(value), ttl);
     } else {
       console.log(picocolors.green('[cache] hit'), picocolors.gray(key));
@@ -168,6 +180,7 @@ export class Cache {
       const deserializer = 'deserializer' in opt ? opt.deserializer : identity;
       value = deserializer(cached);
     }
+
     return value;
   }
 

Build/lib/parse-filter.ts

@@ -13,6 +13,7 @@ import type { Span } from '../trace';
 
 const DEBUG_DOMAIN_TO_FIND: string | null = null; // example.com | null
 let foundDebugDomain = false;
+const temporaryBypass = DEBUG_DOMAIN_TO_FIND !== null;
 
 export function processDomainLists(span: Span, domainListsUrl: string, includeAllSubDomain = false, ttl: number | null = null) {
   return span.traceChild(`process domainlist: ${domainListsUrl}`).traceAsyncFn(() => fsFetchCache.apply(
@@ -38,7 +39,7 @@ export function processDomainLists(span: Span, domainListsUrl: string, includeAl
     },
     {
       ttl,
-      temporaryBypass: DEBUG_DOMAIN_TO_FIND !== null,
+      temporaryBypass,
       serializer: serializeSet,
       deserializer: deserializeSet
     }
@@ -97,7 +98,7 @@ export function processHosts(span: Span, hostsUrl: string, mirrors: string[] | n
     },
     {
       ttl,
-      temporaryBypass: DEBUG_DOMAIN_TO_FIND !== null,
+      temporaryBypass,
       serializer: serializeSet,
       deserializer: deserializeSet
     }
@@ -131,7 +132,11 @@ export async function processFilterRules(
 
       const warningMessages: string[] = [];
 
-      const gorhill = await getGorhillPublicSuffixPromise();
+      const gorhillPromise = getGorhillPublicSuffixPromise();
+      const peekedGorhill = Bun.peek(gorhillPromise);
+      const gorhill = peekedGorhill === gorhillPromise
+        ? await span.traceChild('get gorhill').tracePromise(gorhillPromise)
+        : (peekedGorhill as PublicSuffixList);
 
       /**
      * @param {string} line
@@ -215,7 +220,7 @@ export async function processFilterRules(
     },
     {
       ttl,
-      temporaryBypass: DEBUG_DOMAIN_TO_FIND !== null,
+      temporaryBypass,
       serializer: JSON.stringify,
       deserializer: JSON.parse
     }