stream: improve performance of finished()

The changes optimize the end-of-stream.js module to only preserve
AsyncLocalStorage context when it's actually needed, improving
performance in the common case where no async context tracking is
active.

Author: avcribl

benchmark/streams/end-of-stream.js

@@ -0,0 +1,38 @@
+'use strict';
+
+const common = require('../common');
+const { Readable, Writable, Duplex, finished } = require('stream');
+
+const bench = common.createBenchmark(main, {
+  n: [1e5],
+  streamType: ['readable', 'writable', 'duplex'],
+});
+
+function main({ n, streamType }) {
+  bench.start();
+
+  for (let i = 0; i < n; i++) {
+    let stream;
+
+    switch (streamType) {
+      case 'readable':
+        stream = new Readable({ read() { this.push(null); } });
+        break;
+      case 'writable':
+        stream = new Writable({ write(chunk, enc, cb) { cb(); } });
+        stream.end();
+        break;
+      case 'duplex':
+        stream = new Duplex({
+          read() { this.push(null); },
+          write(chunk, enc, cb) { cb(); },
+        });
+        stream.end();
+        break;
+    }
+
+    finished(stream, () => {});
+  }
+
+  bench.end(n);
+}

lib/internal/streams/end-of-stream.js

@@ -44,6 +44,9 @@ const {
   kIsClosedPromise,
 } = require('internal/streams/utils');
 
+const { getHookArrays } = require('internal/async_hooks');
+const AsyncContextFrame = require('internal/async_context_frame');
+
 // Lazy load
 let AsyncLocalStorage;
 let addAbortListener;
@@ -66,8 +69,13 @@ function eos(stream, options, callback) {
   validateFunction(callback, 'callback');
   validateAbortSignal(options.signal, 'options.signal');
 
-  AsyncLocalStorage ??= require('async_hooks').AsyncLocalStorage;
-  callback = once(AsyncLocalStorage.bind(callback));
+  if (AsyncContextFrame.current() ||
+      getHookArrays()[0].length > 0) {
+    AsyncLocalStorage ??= require('async_hooks').AsyncLocalStorage;
+    callback = once(AsyncLocalStorage.bind(callback));
+  } else {
+    callback = once(callback);
+  }
 
   if (isReadableStream(stream) || isWritableStream(stream)) {
     return eosWeb(stream, options, callback);