perf: avoid new URL() construction for pathname/query extraction in hot paths

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: benfavre

packages/next/src/server/app-render/app-render.tsx

@@ -2117,7 +2117,8 @@ async function renderToHTMLOrFlightImpl(
 
   if (process.env.__NEXT_DEV_SERVER && setIsrStatus && !cacheComponents) {
     // Reset the ISR status at start of request.
-    const { pathname } = new URL(req.url || '/', 'http://n')
+    const reqUrl = req.url || '/'
+    const pathname = reqUrl.split('?', 1)[0]
     setIsrStatus(
       pathname,
       // Only pages using the Node runtime can use ISR, Edge is always dynamic.
@@ -2396,7 +2397,8 @@ async function renderToHTMLOrFlightImpl(
       isNodeNextRequest(req)
     ) {
       req.originalRequest.on('end', () => {
-        const { pathname } = new URL(req.url || '/', 'http://n')
+        const reqUrl = req.url || '/'
+        const pathname = reqUrl.split('?', 1)[0]
         const isStatic = !requestStore.usedDynamic && !workStore.forceDynamic
         setIsrStatus(pathname, isStatic)
       })

packages/next/src/server/base-server.ts

@@ -65,6 +65,7 @@ import { removeTrailingSlash } from '../shared/lib/router/utils/remove-trailing-
 import { denormalizePagePath } from '../shared/lib/page-path/denormalize-page-path'
 import * as Log from '../build/output/log'
 import { getServerUtils } from './server-utils'
+import { getQueryParam } from './internal-utils'
 import isError, { getProperError } from '../lib/is-error'
 import {
   addRequestMeta,
@@ -2090,9 +2091,7 @@ export default abstract class Server<
       )
       const actualHash =
         getRequestMeta(req, 'cacheBustingSearchParam') ??
-        new URL(req.url || '', 'http://localhost').searchParams.get(
-          NEXT_RSC_UNION_QUERY
-        )
+        getQueryParam(req.url || '', NEXT_RSC_UNION_QUERY)
 
       if (expectedHash !== actualHash) {
         // The hash sent by the client does not match the expected value.

packages/next/src/server/internal-utils.ts

@@ -10,6 +10,29 @@ export function stripInternalQueries(query: NextParsedUrlQuery) {
   }
 }
 
+/**
+ * Extract a single query parameter value from a URL string without
+ * constructing a URL object. Returns null if the parameter is not found.
+ */
+export function getQueryParam(url: string, name: string): string | null {
+  const qIdx = url.indexOf('?')
+  if (qIdx === -1) return null
+  const search = url.substring(qIdx + 1)
+  const prefix = name + '='
+  let start = 0
+  while (start <= search.length) {
+    const ampIdx = search.indexOf('&', start)
+    const end = ampIdx === -1 ? search.length : ampIdx
+    const segment = search.substring(start, end)
+    if (segment.startsWith(prefix)) {
+      return decodeURIComponent(segment.substring(prefix.length))
+    }
+    if (segment === name) return ''
+    start = end + 1
+  }
+  return null
+}
+
 export function stripInternalSearchParams<T extends string | URL>(url: T): T {
   const isStringUrl = typeof url === 'string'
   const instance = isStringUrl ? new URL(url) : (url as URL)