querystring: avoid indexOf when parsing

Fixes a performance regression in body-parser with V8 6.0. Removes the use of an auxiliary array, and just query the object directly. PR-URL: #14703 Reviewed-By: Colin Ihrig <[email protected]> Reviewed-By: Anna Henningsen <[email protected]> Reviewed-By: Evan Lucas <[email protected]> Reviewed-By: Sakthipriyan Vairamani <[email protected]> Reviewed-By: Luigi Pinca <[email protected]>
nodejs · Aug 9, 2017 · e813cfa · e813cfa
1 parent a813294
commit e813cfa
Showing 1 changed file with 2 additions and 8 deletions.
diff --git a/lib/querystring.js b/lib/querystring.js
@@ -285,7 +285,6 @@ function parse(qs, sep, eq, options) {
   }
   const customDecode = (decode !== qsUnescape);
 
-  const keys = [];
   var lastPos = 0;
   var sepIdx = 0;
   var eqIdx = 0;
@@ -326,11 +325,8 @@ function parse(qs, sep, eq, options) {
         if (value.length > 0 && valEncoded)
           value = decodeStr(value, decode);
 
-        // Use a key array lookup instead of using hasOwnProperty(), which is
-        // slower
-        if (keys.indexOf(key) === -1) {
+        if (obj[key] === undefined) {
           obj[key] = value;
-          keys[keys.length] = key;
         } else {
           const curValue = obj[key];
           // A simple Array-specific property check is enough here to
@@ -428,10 +424,8 @@ function parse(qs, sep, eq, options) {
     key = decodeStr(key, decode);
   if (value.length > 0 && valEncoded)
     value = decodeStr(value, decode);
-  // Use a key array lookup instead of using hasOwnProperty(), which is slower
-  if (keys.indexOf(key) === -1) {
+  if (obj[key] === undefined) {
     obj[key] = value;
-    keys[keys.length] = key;
   } else {
     const curValue = obj[key];
     // A simple Array-specific property check is enough here to