optimization: locale caching, so we don`t have to reparse instance-config every single time

inc/functions.php

@@ -96,6 +96,13 @@ function loadConfig() {
 
 	// Initialize locale as early as possible
 
+	// Those calls are expensive. Unfortunately, our cache system is not initialized at this point.
+	// So, we may store the locale in a tmp/ filesystem.
+
+	if (file_exists($fn = 'tmp/cache/locale_' . ( isset($board['uri']) ? $board['uri'] : '' ) ) ) {
+		$config['locale'] = file_get_contents($fn);
+	}
+	else {
 		$config['locale'] = 'en';
 
 		$configstr = file_get_contents('inc/instance-config.php');
@@ -110,6 +117,9 @@ function loadConfig() {
 			$config['locale'] = $matches[count($matches)-1];
 		}
 
+		file_put_contents($fn, $config['locale']);
+	}
+
 	if ($config['locale'] != $current_locale) {
 		$current_locale = $config['locale'];
 		init_locale($config['locale'], $error);