buffer: optimize byteLength for common encodings

ronag · targos · commit d04246a0d73a · 2024-10-02T07:57:37.000+02:00
PR-URL: #54342 Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com> Reviewed-By: Yagiz Nizipli <yagiz@nizipli.com> Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
diff --git a/lib/buffer.js b/lib/buffer.js
@@ -780,13 +780,22 @@ function byteLength(string, encoding) {
 if (len === 0)
 return 0;
 
- if (encoding) {
- const ops = getEncodingOps(encoding);
- if (ops) {
- return ops.byteLength(string);
- }
+ if (!encoding || encoding === 'utf8') {
+ return byteLengthUtf8(string);
+ }
+
+ if (encoding === 'ascii') {
+ return len;
 }
- return byteLengthUtf8(string);
+
+ const ops = getEncodingOps(encoding);
+ if (ops === undefined) {
+ // TODO (ronag): Makes more sense to throw here.
+ // throw new ERR_UNKNOWN_ENCODING(encoding);
+ return byteLengthUtf8(string);
+ }
+
+ return ops.byteLength(string);
 }
 
 Buffer.byteLength = byteLength;

-Original file line number
+Diff line change
 if(len===0)
 return0;
 -if(encoding){
 -constops=getEncodingOps(encoding);
 -if(ops){
 -returnops.byteLength(string);
 -}
 +if(!encoding||encoding==='utf8'){
 +returnbyteLengthUtf8(string);
 +}
++
 +if(encoding==='ascii'){
 +returnlen;
+}
 -returnbyteLengthUtf8(string);
++
 +constops=getEncodingOps(encoding);
 +if(ops===undefined){
 +// TODO (ronag): Makes more sense to throw here.
 +// throw new ERR_UNKNOWN_ENCODING(encoding);
 +returnbyteLengthUtf8(string);
 +}
++
 +returnops.byteLength(string);
+}
 Buffer.byteLength=byteLength;