buffer: use native copy impl

nodejs · Jul 28, 2024 · ce07761 · ce07761
1 parent 8a41d9b
commit ce07761
Showing 1 changed file with 14 additions and 3 deletions.
diff --git a/lib/buffer.js b/lib/buffer.js
@@ -58,6 +58,7 @@ const {
   byteLengthUtf8,
   compare: _compare,
   compareOffset,
+  copyArrayBuffer,
   createFromString,
   fill: bindingFill,
   isAscii: bindingIsAscii,
@@ -248,10 +249,20 @@ function _copyActual(source, target, targetStart, sourceStart, sourceEnd) {
   if (nb > sourceLen)
     nb = sourceLen;
 
-  if (sourceStart !== 0 || sourceEnd < source.length)
-    source = new Uint8Array(source.buffer, source.byteOffset + sourceStart, nb);
+  if (nb <= 0)
+    return 0;
 
-  TypedArrayPrototypeSet(target, source, targetStart);
+  if (sourceStart !== 0 || sourceEnd < source.length) {
+    copyArrayBuffer(
+      target.buffer,
+      target.byteOffset + targetStart,
+      source.buffer,
+      source.byteOffset + sourceStart,
+      nb,
+    );
+  } else {
+    TypedArrayPrototypeSet(target, source, targetStart);
+  }
 
   return nb;
 }