reorder maps to make binary encoding more efficient

Author: sokra

lib/serialization/MapObjectSerializer.js

@@ -7,16 +7,22 @@
 class MapObjectSerializer {
 	serialize(obj, { write }) {
 		write(obj.size);
-		for (const [key, value] of obj) {
+		for (const key of obj.keys()) {
 			write(key);
+		}
+		for (const value of obj.values()) {
 			write(value);
 		}
 	}
 	deserialize({ read }) {
 		let size = read();
 		const map = new Map();
+		const keys = [];
+		for (let i = 0; i < size; i++) {
+			keys.push(read());
+		}
 		for (let i = 0; i < size; i++) {
-			map.set(read(), read());
+			map.set(keys[i], read());
 		}
 		return map;
 	}