Replace String with Arc<str> for fields that contain repeated static
values (mime_type, icon_class, icon_special_class, category) in
FileDto, FolderDto, and OptimizedFileContent.
These fields are computed from ~40 static lookup tables and cloned
on every request. With Arc<str>, clone becomes O(1) atomic increment
instead of O(n) heap allocation — saving thousands of allocations/s
under load.
Fields kept as String: id, name, path, folder_id, owner_id
(unique per item, rarely cloned).
Zero API impact — serde serializes Arc<str> identically to String.
https://claude.ai/code/session_01EbAFEfyJNLRmJHmmYDX3Tt
Replace the double-query pattern (get_folder_by_path + get_file_by_path)
across PROPFIND, HEAD, DELETE, MOVE, and COPY handlers with a single
UNION ALL query via PathResolverService.
PG Append node short-circuits on LIMIT 1: if the folder branch matches,
the file branch is never executed. Cuts WebDAV path resolution from
2 round-trips to 1 per request.
Also adds an exists() method using EXISTS subqueries for the Overwrite
header checks in MOVE/COPY (avoids constructing full DTOs).
Legacy double-query fallback retained when PathResolver is unavailable.
Dionisio