buffer: preallocate array with buffer length

alemures · Italo A. Casas · commit 6feea085876b · 2017-04-10T13:44:42.000-04:00
Because the final array length is known, it's better to allocate its final length at initialization time to avoid future reallocations. Also add an explicit buffer length greater than 0 comparison so it's more readable, avoids the internal ToBoolean call and follows the standard Node.js API format (as it can be checked in other similar structures where 'length > 0' is preferred over 'length') PR-URL: #11733 Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Anna Henningsen <anna@addaleax.net> Reviewed-By: Colin Ihrig <cjihrig@gmail.com> Reviewed-By: Brian White <mscdex@mscdex.net>
diff --git a/lib/buffer.js b/lib/buffer.js
@@ -799,8 +799,8 @@ Buffer.prototype.write = function(string, offset, length, encoding) {
 
 
 Buffer.prototype.toJSON = function() {
-  if (this.length) {
-    const data = [];
+  if (this.length > 0) {
+    const data = new Array(this.length);
     for (var i = 0; i < this.length; ++i)
       data[i] = this[i];
     return { type: 'Buffer', data };
