reuse TextDecoder

Author: mischnic

index.js

@@ -478,6 +478,8 @@ function byteLength (string, encoding) {
 }
 Buffer.byteLength = byteLength
 
+let decoderUTF8 = new TextDecoder("utf8");
+
 function slowToString (encoding, start, end) {
   let loweredCase = false
 
@@ -522,7 +524,7 @@ function slowToString (encoding, start, end) {
 
       case 'utf8':
       case 'utf-8':
-        return new TextDecoder(encoding).decode(this.slice(start, end))
+        return decoderUTF8.decode(this.slice(start, end))
 
       case 'ascii':
         return asciiSlice(this, start, end)