backend v4 half

SerpentRace_Backend/node_modules/libphonenumber-js/source/findNumbers/RegExpCache.js

@@ -0,0 +1,20 @@
+import LRUCache from './LRUCache.js'
+
+// A cache for frequently used country-specific regular expressions. Set to 32 to cover ~2-3
+// countries being used for the same doc with ~10 patterns for each country. Some pages will have
+// a lot more countries in use, but typically fewer numbers for each so expanding the cache for
+// that use-case won't have a lot of benefit.
+export default class RegExpCache {
+	constructor(size) {
+		this.cache = new LRUCache(size)
+	}
+
+	getPatternForRegExp(pattern) {
+		let regExp = this.cache.get(pattern)
+		if (!regExp) {
+			regExp = new RegExp('^' + pattern)
+			this.cache.put(pattern, regExp)
+		}
+		return regExp
+	}
+}