Replace dictionary object with Map in Separate namespace for private …

…vars in unmangled var name transform [perf]
overlookmotel · Nov 21, 2023 · 6c24239 · 6c24239
1 parent 9ec267f
commit 6c24239
Showing 1 changed file with 3 additions and 4 deletions.
diff --git a/lib/serialize/varNames.js b/lib/serialize/varNames.js
@@ -92,16 +92,15 @@ const NAME_REGEX = /^(.*?)(?:\$(\d+))?$/;
 class UnmangledVarNameFactory extends VarNameFactory {
 	constructor(reservedNames) {
 		super(reservedNames);
-		this.used = Object.create(null);
+		this.used = new Map();
 	}
 
 	transform(name, isPrivate) {
 		if (isPrivate) name = `${PRIVATE_PREFIX}${name}`;
 		const [, nameWithoutPostfix, numStr] = name.match(NAME_REGEX);
 		let num = numStr ? numStr * 1 : -1;
 
-		const {used} = this;
-		const usedNum = used[nameWithoutPostfix];
+		const usedNum = this.used.get(nameWithoutPostfix);
 		if (usedNum !== undefined && num <= usedNum) num = usedNum + 1;
 
 		let outName = nameWithoutPostfix;
@@ -111,7 +110,7 @@ class UnmangledVarNameFactory extends VarNameFactory {
 			num++;
 		}
 
-		used[nameWithoutPostfix] = num;
+		this.used.set(nameWithoutPostfix, num);
 
 		return outName;
 	}