util: implement fifo cache with safemap

Author: araujogui

lib/util.js

@@ -38,6 +38,7 @@ const {
   ObjectValues,
   ReflectApply,
   RegExpPrototypeExec,
+  SafeMap,
   StringPrototypeSlice,
   StringPrototypeToWellFormed,
 } = primordials;
@@ -118,7 +119,29 @@ const kBoldCode = 1;
 const kHexCloseSeq = kEscape + '39' + kEscapeEnd;
 
 let styleCache;
-const hexStyleCache = { __proto__: null };
+
+const kHexStyleCacheMax = 256;
+
+class HexStyleFIFOCache {
+  #cache = new SafeMap();
+
+  get(key) {
+    return this.#cache.get(key);
+  }
+
+  set(key, value) {
+    if (this.#cache.size >= kHexStyleCacheMax)
+      this.#cache.delete(this.#cache.keys().next().value);
+    this.#cache.set(key, value);
+  }
+}
+
+let hexStyleCache;
+
+function getHexStyleCache() {
+  hexStyleCache ??= new HexStyleFIFOCache();
+  return hexStyleCache;
+}
 
 function getStyleCache() {
   if (styleCache === undefined) {
@@ -148,15 +171,16 @@ function getStyleCache() {
  * @returns {{openSeq: string, closeSeq: string}}
  */
 function getHexStyle(hex) {
-  const cached = hexStyleCache[hex];
+  const cache = getHexStyleCache();
+  const cached = cache.get(hex);
   if (cached !== undefined) return cached;
   const { 0: r, 1: g, 2: b } = hexToRgb(hex);
   const style = {
     __proto__: null,
     openSeq: kEscape + rgbToAnsi24Bit(r, g, b) + kEscapeEnd,
     closeSeq: kHexCloseSeq,
   };
-  hexStyleCache[hex] = style;
+  cache.set(hex, style);
   return style;
 }
 
@@ -241,7 +265,7 @@ function styleText(format, text, options) {
     }
 
     if (format[0] === '#') {
-      let hexStyle = hexStyleCache[format];
+      let hexStyle = getHexStyleCache().get(format);
       if (hexStyle === undefined && RegExpPrototypeExec(hexColorRegExp, format) !== null) {
         hexStyle = getHexStyle(format);
       }
@@ -281,7 +305,7 @@ function styleText(format, text, options) {
     if (key === 'none') continue;
 
     if (typeof key === 'string' && key[0] === '#') {
-      let hexStyle = hexStyleCache[key];
+      let hexStyle = getHexStyleCache().get(key);
       if (hexStyle === undefined) {
         if (RegExpPrototypeExec(hexColorRegExp, key) === null) {
           throw new ERR_INVALID_ARG_VALUE('format', key,