perf(get): reduce request entry allocations (#6029)

Co-authored-by: heihutu <heihutu@gmail.com>

crates/utils/src/path.rs

@@ -12,6 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+use std::borrow::Cow;
 use std::path::Component;
 use std::path::Path;
 use std::path::PathBuf;
@@ -44,14 +45,19 @@ pub fn has_suffix(s: &str, suffix: &str) -> bool {
 /// If the object name ends with a slash, it is considered a directory object.
 /// The trailing slash is removed and `GLOBAL_DIR_SUFFIX` is appended.
 /// If it does not end with a slash, the name is returned as is.
-pub fn encode_dir_object(object: &str) -> String {
+pub fn encode_dir_object_ref(object: &str) -> Cow<'_, str> {
     if has_suffix(object, SLASH_SEPARATOR) {
-        format!("{}{}", object.trim_end_matches(SLASH_SEPARATOR), GLOBAL_DIR_SUFFIX)
+        Cow::Owned(format!("{}{}", object.trim_end_matches(SLASH_SEPARATOR), GLOBAL_DIR_SUFFIX))
     } else {
-        object.to_string()
+        Cow::Borrowed(object)
     }
 }
 
+/// Owned compatibility wrapper for callers that retain or mutate the encoded name.
+pub fn encode_dir_object(object: &str) -> String {
+    encode_dir_object_ref(object).into_owned()
+}
+
 /// Checks if the given object name represents a directory object.
 ///
 /// Returns true if the object name ends with `GLOBAL_DIR_SUFFIX`.
@@ -602,6 +608,17 @@ mod tests {
     use super::*;
     use proptest::prelude::*;
 
+    #[test]
+    fn encode_dir_object_ref_borrows_objects_and_encodes_directories() {
+        let object = "prefix/object";
+        let encoded = encode_dir_object_ref(object);
+        assert!(matches!(encoded, Cow::Borrowed(value) if value == object));
+
+        let encoded = encode_dir_object_ref("prefix/directory/");
+        assert!(matches!(encoded, Cow::Owned(ref value) if value == "prefix/directory__XLDIR__"));
+        assert_eq!(encode_dir_object("prefix/directory/"), encoded);
+    }
+
     #[test]
     fn test_trim_etag() {
         // Test with quoted ETag