url: offload URLSearchParams initialization

lib/internal/url.js

@@ -100,6 +100,7 @@ const FORWARD_SLASH = /\//g;
 
 const context = Symbol('context');
 const searchParams = Symbol('query');
+const kDirty = Symbol('dirty');
 
 const updateActions = {
  kProtocol: 0,
@@ -224,11 +225,12 @@ class URLSearchParams {
  } else {
  // USVString
  init = toUSVString(init);
- initSearchParams(this, init);
+ this[searchParams] = init ? parseParams(init) : [];
  }
 
  // "associated url object"
  this[context] = null;
+ this[kDirty] = false;
  }
 
  [inspect.custom](recurseTimes, ctx) {
@@ -545,6 +547,7 @@ class URL {
  input = `${input}`;
  this[context] = new URLContext();
  this.#onParseComplete = FunctionPrototypeBind(this.#onParseComplete, this);
+ this.#onSearchUpdate = FunctionPrototypeBind(this.#onSearchUpdate, this);
 
  if (base !== undefined) {
  base = `${base}`;
@@ -604,11 +607,34 @@ class URL {
  ctx.password = password;
  ctx.port = port;
  ctx.hash = hash;
- if (!this[searchParams]) { // Invoked from URL constructor
- this[searchParams] = new URLSearchParams();
+ if (this[searchParams]) {
+ // Update `kDirty` property to recalculate searchParams on access.
+ // This is done to reduce the overhead of initializing the URL.
+ this[searchParams][kDirty] = true;
+ }
+ };
+
+ #onSearchUpdate = (href, origin, protocol, hostname, pathname,
+ search, username, password, port, hash) => {
+ const ctx = this[context];
+ ctx.href = href;
+ ctx.origin = origin;
+ ctx.protocol = protocol;
+ ctx.hostname = hostname;
+ ctx.pathname = pathname;
+ ctx.search = search;
+ ctx.username = username;
+ ctx.password = password;
+ ctx.port = port;
+ ctx.hash = hash;
+
+ if (this[searchParams] == null) {
+ this[searchParams] = new URLSearchParams(this[context].search);
  this[searchParams][context] = this;
+ } else {
+ this[searchParams][searchParams] = this[context].search ? parseParams(this[context].search) : [];
+ this[searchParams][kDirty] = false;
  }
- initSearchParams(this[searchParams], ctx.search);
  };
 
  toString() {
@@ -729,18 +755,25 @@ class URL {
  return this[context].search;
  }
 
- set search(search) {
+ set search(value) {
  if (!isURLThis(this))
  throw new ERR_INVALID_THIS('URL');
- search = toUSVString(search);
- updateUrl(this[context].href, updateActions.kSearch, search, this.#onParseComplete);
- initSearchParams(this[searchParams], this[context].search);
+ updateUrl(this[context].href, updateActions.kSearch, toUSVString(value), this.#onSearchUpdate);
  }
 
  // readonly
  get searchParams() {
  if (!isURLThis(this))
  throw new ERR_INVALID_THIS('URL');
+ // Create URLSearchParams on demand to greatly improve the URL performance.
+ if (this[searchParams] == null) {
+ this[searchParams] = new URLSearchParams(this[context].search);
+ this[searchParams][context] = this;
+ } else if (this[searchParams][kDirty]) {
+ const updated = this[context].search;
+ this[searchParams][searchParams] = updated ? parseParams(updated) : [];
+ this[searchParams][kDirty] = false;
+ }
  return this[searchParams];
  }
 
@@ -815,14 +848,6 @@ ObjectDefineProperties(URL, {
  revokeObjectURL: kEnumerableProperty,
 });
 
-function initSearchParams(url, init) {
- if (!init) {
- url[searchParams] = [];
- return;
- }
- url[searchParams] = parseParams(init);
-}
-
 // application/x-www-form-urlencoded parser
 // Ref: https://url.spec.whatwg.org/#concept-urlencoded-parser
 function parseParams(qs) {