[perf] Use TypedArray#set() instead of Buffer#copy()

Author: lpinca

lib/buffer-util.js

@@ -19,7 +19,7 @@ function concat(list, totalLength) {
 
   for (let i = 0; i < list.length; i++) {
     const buf = list[i];
-    buf.copy(target, offset);
+    target.set(buf, offset);
     offset += buf.length;
   }
 

lib/receiver.js

@@ -96,11 +96,12 @@ class Receiver extends Writable {
 
     do {
       const buf = this._buffers[0];
+      const offset = dst.length - n;
 
       if (n >= buf.length) {
-        this._buffers.shift().copy(dst, dst.length - n);
+        dst.set(this._buffers.shift(), offset);
       } else {
-        buf.copy(dst, dst.length - n, 0, n);
+        dst.set(new Uint8Array(buf.buffer, buf.byteOffset, n), offset);
         this._buffers[0] = buf.slice(n);
       }