Replace the attribute-presence check (asserts a cache_clear attribute the decorator does not
expose) with one invariant: eight concurrent projects/tree requests run the profile scan once
and each caller gets its own copy of the payload. The scope-suite fixture now disables the TTL
instead of calling a non-existent clear hook, which silently no-op'd.
The all-profiles sidebar polls GET /api/profiles/projects/tree, the one
heavy sidebar endpoint that was not wrapped in @_sidebar_singleflight_cache.
Every poll fanned out list_profiles() + _build_project_tree() over every
profile (51 on this box, ~17k SKILL.md files walked), and each profile
resolution re-parsed its config.yaml because read_user_config_raw() ran
uncached. On a 2-vCore VPS running 'hermes serve' for the Desktop remote
backend this pinned both cores (py-spy: 110-116% sustained, HostHighCPU).
- Wrap get_profiles_projects_tree in the existing single-flight cache,
matching get_profiles_sessions_sidebar (5s TTL, errors[] not cached).
- Memoize read_user_config_raw() on a (st_dev, st_ino, st_size,
st_mtime_ns) fingerprint under _CONFIG_LOCK, same strategy as
read_raw_config(). Hits return a deepcopy so write-back round-trips keep
their fresh-dict semantics; parse errors are never cached; the docstring
no longer claims 'no caching'.
- Tests: memo semantics (deepcopy isolation, inode-replace reparse, error
non-caching, parse-count), a wrapper-presence pin for both heavy sidebar
endpoints, and a cold-cache autouse fixture in the scope tests (the 5s
TTL otherwise leaks one test's payload into the next).
Measured on the affected box: list_profiles 1.9s -> 0.16s warm, serve CPU
112% -> 22-34%, host CPU 50-70% -> ~26%.
The sidebar reports a profile it could not scan as HTTP 200 with an empty
page and errors=[{profile}]. The renderer merges that page keeping only
working, pinned, and selected rows, so every idle Yesterday / This-week
session disappears until a later scan succeeds — and the 5s coalescing cache
then serves the same empty payload back for the rest of its TTL.
Carry the previous rows forward for exactly the profiles named in errors[],
keyed by profile::id so a twin id in another profile is never stitched in.
Profiles that scanned cleanly are still authoritative, so a genuinely empty
page with no errors still clears the list. Per-profile usage and truncation
flags follow the same rule rather than zeroing under a list that was kept.
The legacy per-slice fallback stamps errors on the slice that actually
failed, so a cron read failure can no longer blank recents.
Part of #73847
Part of #88528
Co-authored-by: AKAZIK-py <AKAZIK-py@users.noreply.github.com>
kshitijk4poor