- data.py: non-blocking load_bundle(); background watcher thread refreshes
the parquet cache (5s scan, 30s min rebuild cadence); refresh()/
up_to_date()/generation()
- statistics tab: one table per benchmark (vs <label>), plain column names
(beta/alpha/return/vol...), selectable+reorderable stat list in
settings.json
- correlation tab: per-portfolio components-vs-benchmarks +
all-portfolios-vs-benchmarks; numbered columns
- global date range (window radio + start/end boxes) applied to all tabs;
metrics.xcorr(); equity window radio gains YTD/3M/1M
The cache now tracks every file in the data dir (mtime_ns + size) in
.cache/manifest.json. On load, a directory scan is compared against the
manifest:
- changed/added files are re-read and merged into the parquet panels
(one read + one concat + one write per touched panel; new values
win where present, old values kept where the new file is short)
- removed files drop their symbols (and names)
- an up-to-date cache is a ~30 ms memo hit
Measured on the real 4k-symbol set: full build 54 s, refresh of
5 modified + 1 added + 1 removed files 3.4 s. No scan TTL (a scan is
a few ms); a previous 5 s scan cache masked data updates.
Tests: tests/test_data.py (11 checks) added as step 1 of run_tests.sh.
