querystring: improve performance

PR-URL: #29306
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: Yongsheng Zhang <zyszys98@gmail.com>

lib/querystring.js

@@ -174,19 +174,22 @@ function stringify(obj, sep, eq, options) {
  for (var i = 0; i < len; ++i) {
  var k = keys[i];
  var v = obj[k];
- var ks = encode(stringifyPrimitive(k)) + eq;
+ var ks = encode(stringifyPrimitive(k));
+ ks += eq;
 
  if (Array.isArray(v)) {
  var vlen = v.length;
  if (vlen === 0) continue;
  var vlast = vlen - 1;
  for (var j = 0; j < vlen; ++j) {
- fields += ks + encode(stringifyPrimitive(v[j]));
+ fields += ks;
+ fields += encode(stringifyPrimitive(v[j]));
  if (j < vlast)
  fields += sep;
  }
  } else {
- fields += ks + encode(stringifyPrimitive(v));
+ fields += ks;
+ fields += encode(stringifyPrimitive(v));
  }
 
  if (i < flast)
@@ -200,14 +203,34 @@ function stringify(obj, sep, eq, options) {
 function charCodes(str) {
  if (str.length === 0) return [];
  if (str.length === 1) return [str.charCodeAt(0)];
- const ret = [];
+ const ret = new Array(str.length);
  for (var i = 0; i < str.length; ++i)
- ret[ret.length] = str.charCodeAt(i);
+ ret[i] = str.charCodeAt(i);
  return ret;
 }
 const defSepCodes = [38]; // &
 const defEqCodes = [61]; // =
 
+function addKeyVal(obj, key, value, keyEncoded, valEncoded, decode) {
+ if (key.length > 0 && keyEncoded)
+ key = decodeStr(key, decode);
+ if (value.length > 0 && valEncoded)
+ value = decodeStr(value, decode);
+
+ if (obj[key] === undefined) {
+ obj[key] = value;
+ } else {
+ const curValue = obj[key];
+ // A simple Array-specific property check is enough here to
+ // distinguish from a string value and is faster and still safe
+ // since we are generating all of the values being assigned.
+ if (curValue.pop)
+ curValue[curValue.length] = value;
+ else
+ obj[key] = [curValue, value];
+ }
+}
+
 // Parse a key/val string.
 function parse(qs, sep, eq, options) {
  const obj = Object.create(null);
@@ -272,23 +295,8 @@ function parse(qs, sep, eq, options) {
  value += qs.slice(lastPos, end);
  }
 
- if (key.length > 0 && keyEncoded)
- key = decodeStr(key, decode);
- if (value.length > 0 && valEncoded)
- value = decodeStr(value, decode);
+ addKeyVal(obj, key, value, keyEncoded, valEncoded, decode);
 
- if (obj[key] === undefined) {
- obj[key] = value;
- } else {
- const curValue = obj[key];
- // A simple Array-specific property check is enough here to
- // distinguish from a string value and is faster and still safe
- // since we are generating all of the values being assigned.
- if (curValue.pop)
- curValue[curValue.length] = value;
- else
- obj[key] = [curValue, value];
- }
  if (--pairs === 0)
  return obj;
  keyEncoded = valEncoded = customDecode;
@@ -370,22 +378,8 @@ function parse(qs, sep, eq, options) {
  // We ended on an empty substring
  return obj;
  }
- if (key.length > 0 && keyEncoded)
- key = decodeStr(key, decode);
- if (value.length > 0 && valEncoded)
- value = decodeStr(value, decode);
- if (obj[key] === undefined) {
- obj[key] = value;
- } else {
- const curValue = obj[key];
- // A simple Array-specific property check is enough here to
- // distinguish from a string value and is faster and still safe since
- // we are generating all of the values being assigned.
- if (curValue.pop)
- curValue[curValue.length] = value;
- else
- obj[key] = [curValue, value];
- }
+
+ addKeyVal(obj, key, value, keyEncoded, valEncoded, decode);
 
  return obj;
 }