sort: because of perf, only enable try_init_collator when relevant

Author: sylvestre

src/uu/sort/src/sort.rs

@@ -1038,12 +1038,31 @@ fn get_rlimit() -> UResult<usize> {
 
 const STDIN_FILE: &str = "-";
 
+/// Check if locale-aware collation will be needed based on sort settings and locale
+fn will_need_locale_collation(settings: &GlobalSettings) -> bool {
+    // First check if we're using the C locale (DEFAULT_LOCALE), which doesn't need collator
+    let (locale, _) = uucore::i18n::get_collating_locale();
+    if *locale == uucore::i18n::DEFAULT_LOCALE {
+        return false;
+    }
+
+    // Check each selector to see if any would use locale comparison
+    for selector in &settings.selectors {
+        let key_settings = &selector.settings;
+        if key_settings.mode == SortMode::Default
+            && !key_settings.ignore_case
+            && !key_settings.ignore_non_printing
+            && !key_settings.dictionary_order
+        {
+            return true;
+        }
+    }
+    false
+}
+
 #[uucore::main]
 #[allow(clippy::cognitive_complexity)]
 pub fn uumain(args: impl uucore::Args) -> UResult<()> {
-    // Initialize locale-aware collator for string comparisons
-    uucore::i18n::collator::try_init_collator(CollatorOptions::default());
-
     let mut settings = GlobalSettings::default();
 
     let matches = uucore::clap_localization::handle_clap_result_with_exit_code(uu_app(), args, 2)?;
@@ -1322,6 +1341,11 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
 
     settings.init_precomputed();
 
+    // Initialize locale-aware collator only if needed for string comparisons
+    if will_need_locale_collation(&settings) {
+        uucore::i18n::collator::try_init_collator(CollatorOptions::default());
+    }
+
     let result = exec(&mut files, &settings, output, &mut tmp_dir);
     // Wait here if `SIGINT` was received,
     // for signal handler to do its work and terminate the program.

src/uucore/src/lib/features/i18n/mod.rs

@@ -20,7 +20,7 @@ pub enum UEncoding {
     Utf8,
 }
 
-const DEFAULT_LOCALE: Locale = locale!("en-US-posix");
+pub const DEFAULT_LOCALE: Locale = locale!("en-US-posix");
 
 /// Look at 3 environment variables in the following order
 ///
@@ -64,7 +64,7 @@ fn get_locale_from_env(locale_name: &str) -> (Locale, UEncoding) {
 }
 
 /// Get the collating locale from the environment
-fn get_collating_locale() -> &'static (Locale, UEncoding) {
+pub fn get_collating_locale() -> &'static (Locale, UEncoding) {
     static COLLATING_LOCALE: OnceLock<(Locale, UEncoding)> = OnceLock::new();
 
     COLLATING_LOCALE.get_or_init(|| get_locale_from_env("LC_COLLATE"))