From c2da31c37781ffa5b702bf7db63e531bf9bfb4fc Mon Sep 17 00:00:00 2001
From: Haoyu Qiu <timothyqiu32@gmail.com>
Date: Wed, 16 Oct 2024 20:23:59 +0800
Subject: [PATCH] Cache results for `TranslationServer.compare_locales()`

---
 core/string/translation.cpp | 40 +++++++++++++++++++++++++------------
 core/string/translation.h   |  2 ++
 2 files changed, 29 insertions(+), 13 deletions(-)

diff --git a/core/string/translation.cpp b/core/string/translation.cpp
index edd75902c..8b9fe353a 100644
--- a/core/string/translation.cpp
+++ b/core/string/translation.cpp
@@ -358,32 +358,46 @@ String TranslationServer::_standardize_locale(const String &p_locale, bool p_add
 }
 
 int TranslationServer::compare_locales(const String &p_locale_a, const String &p_locale_b) const {
+	if (p_locale_a == p_locale_b) {
+		// Exact match.
+		return 10;
+	}
+
+	const String cache_key = p_locale_a + "|" + p_locale_b;
+	const int *cached_result = locale_compare_cache.getptr(cache_key);
+	if (cached_result) {
+		return *cached_result;
+	}
+
 	String locale_a = _standardize_locale(p_locale_a, true);
 	String locale_b = _standardize_locale(p_locale_b, true);
 
 	if (locale_a == locale_b) {
 		// Exact match.
+		locale_compare_cache.set(cache_key, 10);
 		return 10;
 	}
 
 	Vector<String> locale_a_elements = locale_a.split("_");
 	Vector<String> locale_b_elements = locale_b.split("_");
-	if (locale_a_elements[0] == locale_b_elements[0]) {
-		// Matching language, both locales have extra parts.
-		// Return number of matching elements.
-		int matching_elements = 1;
-		for (int i = 1; i < locale_a_elements.size(); i++) {
-			for (int j = 1; j < locale_b_elements.size(); j++) {
-				if (locale_a_elements[i] == locale_b_elements[j]) {
-					matching_elements++;
-				}
-			}
-		}
-		return matching_elements;
-	} else {
+	if (locale_a_elements[0] != locale_b_elements[0]) {
 		// No match.
+		locale_compare_cache.set(cache_key, 0);
 		return 0;
 	}
+
+	// Matching language, both locales have extra parts.
+	// Return number of matching elements.
+	int matching_elements = 1;
+	for (int i = 1; i < locale_a_elements.size(); i++) {
+		for (int j = 1; j < locale_b_elements.size(); j++) {
+			if (locale_a_elements[i] == locale_b_elements[j]) {
+				matching_elements++;
+			}
+		}
+	}
+	locale_compare_cache.set(cache_key, matching_elements);
+	return matching_elements;
 }
 
 String TranslationServer::get_locale_name(const String &p_locale) const {
diff --git a/core/string/translation.h b/core/string/translation.h
index 0e75e21ee..b8cf4563a 100644
--- a/core/string/translation.h
+++ b/core/string/translation.h
@@ -88,6 +88,8 @@ class TranslationServer : public Object {
 	Ref<Translation> tool_translation;
 	Ref<Translation> doc_translation;
 
+	mutable HashMap<String, int> locale_compare_cache;
+
 	bool enabled;
 
 	static TranslationServer *singleton;