buffer,util: refactor for performance

internal/util.js definied toInteger() and toLength() but they were only
used by buffer.js. Inlining these small functions results in a small but
statistically-significant performance gain.

PR-URL: https://github.com/nodejs/node/pull/12153
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

1 files changed, 8 insertions, 2 deletions

diff --git a/lib/buffer.js b/lib/buffer.js
index b9c6c01425..0df3ab297e 100644
--- a/lib/buffer.js
+++ b/lib/buffer.js
@@ -254,7 +254,9 @@ function fromArrayLike(obj) {
 }
 
 function fromArrayBuffer(obj, byteOffset, length) {
-  byteOffset = internalUtil.toInteger(byteOffset);
+  // convert byteOffset to integer
+  byteOffset = +byteOffset;
+  byteOffset = byteOffset ? Math.trunc(byteOffset) : 0;
 
   const maxLength = obj.byteLength - byteOffset;
 
@@ -264,7 +266,11 @@ function fromArrayBuffer(obj, byteOffset, length) {
   if (length === undefined) {
     length = maxLength;
   } else {
-    length = internalUtil.toLength(length);
+    // convert length to non-negative integer
+    length = +length;
+    length = length ? Math.trunc(length) : 0;
+    length = length <= 0 ? 0 : Math.min(length, Number.MAX_SAFE_INTEGER);
+
     if (length > maxLength)
       throw new RangeError("'length' is out of bounds");
   }