stream: resolve perf regression introduced by V8 7.3

This commit contains two fixes:
1. use instanceof instead of Object.getPrototypeOf, as checking an
   object prototype with Object.getPrototypeOf is slower
   than an instanceof check.
2. avoid parseInt(undefined, 10) to get NaN as it regressed.

PR-URL: https://github.com/nodejs/node/pull/28842
Fixes: https://github.com/nodejs/node/issues/28586
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Anto Aravinth <anto.aravinth.cse@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>

1 files changed, 9 insertions, 2 deletions

diff --git a/lib/_stream_readable.js b/lib/_stream_readable.js
index 5b73646db8..754e45da64 100644
--- a/lib/_stream_readable.js
+++ b/lib/_stream_readable.js
@@ -256,7 +256,8 @@ function readableAddChunk(stream, chunk, encoding, addToFront) {
     } else if (state.objectMode || chunk && chunk.length > 0) {
       if (typeof chunk !== 'string' &&
           !state.objectMode &&
-          Object.getPrototypeOf(chunk) !== Buffer.prototype) {
+          // Do not use Object.getPrototypeOf as it is slower since V8 7.3.
+          !(chunk instanceof Buffer)) {
         chunk = Stream._uint8ArrayToBuffer(chunk);
       }
 
@@ -399,7 +400,13 @@ function howMuchToRead(n, state) {
 // You can override either this method, or the async _read(n) below.
 Readable.prototype.read = function(n) {
   debug('read', n);
-  n = parseInt(n, 10);
+  // Same as parseInt(undefined, 10), however V8 7.3 performance regressed
+  // in this scenario, so we are doing it manually.
+  if (n === undefined) {
+    n = NaN;
+  } else if (!Number.isInteger(n)) {
+    n = parseInt(n, 10);
+  }
   const state = this._readableState;
   const nOrig = n;