Make QueryString.parse() even faster

lib/querystring.js

@@ -175,6 +175,7 @@ QueryString.parse = QueryString.decode = function(qs, sep, eq, options) {
     return obj;
   }
 
+  var regexp = /\+/g;
   qs = qs.split(sep);
 
   // maxKeys <= 0 means that we should not limit keys count
@@ -182,17 +183,18 @@ QueryString.parse = QueryString.decode = function(qs, sep, eq, options) {
     qs = qs.slice(0, maxKeys);
   }
 
-  qs.forEach(function(kvp) {
-    var x = kvp.split(eq), k, v, useQS = false;
+  for (var i = 0, len = qs.length; i < len; ++i) {
+    var x = qs[i].replace(regexp, '%20'),
+        idx = x.indexOf(eq),
+        kstr = x.substring(0, idx),
+        vstr = x.substring(idx + 1), k, v;
+
     try {
-      if (kvp.match(/\+/)) { // decodeURIComponent does not decode + to space
-        throw 'has +';
-      }
-      k = decodeURIComponent(x[0]);
-      v = decodeURIComponent(x.slice(1).join(eq) || '');
-    } catch (e) {
-      k = QueryString.unescape(x[0], true);
-      v = QueryString.unescape(x.slice(1).join(eq), true);
+      k = decodeURIComponent(kstr);
+      v = decodeURIComponent(vstr);
+    } catch(e) {
+      k = QueryString.unescape(kstr, true);
+      v = QueryString.unescape(vstr, true);
     }
 
     if (!hasOwnProperty(obj, k)) {
@@ -202,7 +204,7 @@ QueryString.parse = QueryString.decode = function(qs, sep, eq, options) {
     } else {
       obj[k].push(v);
     }
-  });
+  }
 
   return obj;
 };