The post-update state.db integrity guard called verify_sqlite_integrity()
with max_bytes=0, which disables the size ceiling and forces a full
PRAGMA integrity_check. That pragma walks every b-tree page in the file,
so its cost scales with database size — measured on a real 30 GB state.db:
143.5s with a cold page cache (worse under an update's memory pressure),
with zero output on screen. The update looks hung right after
"✓ Code updated!" and a CPU sits pegged.
Multi-GB session databases are normal for heavy users, so a
size-unbounded check is never an acceptable default on the update path.
- verify_sqlite_integrity(): max_bytes now defaults to
DEFAULT_INTEGRITY_CHECK_MAX_BYTES (2 GiB) instead of 0. max_bytes=0
remains the explicit opt-in for a full scan.
- The oversized path no longer degrades to a header-only check: it adds a
constant-time structural probe (read-only open + schema_version +
sqlite_master read) so the malformed-schema class is still caught, not
just the #68474 zeroed-file signature.
- Drop the explicit max_bytes=0 at the post-update guard and in
copy_db_and_verify() so both inherit the bounded default.
Measured on the reporter's real 30 GB state.db: 143.5s cold → 0.001s,
still valid=True. Corruption detection verified at multi-GB scale for
both classes (zeroed header, malformed schema) — both still fail closed.
Tests: default-is-bounded invariant, oversized probe catches malformed
schema, max_bytes=0 still forces the full check.
Follow-up fixes on top of the cherry-picked guard:
- verify_sqlite_integrity(): an oversized (max_bytes-exceeding) database
now still fails on a zeroed/invalid header — previously valid=True was
set before the header check, so a >1GiB zeroed state.db (the exact
#68474 signature at 95MB scale) passed as valid.
- _run_pre_update_backup(): the guard referenced get_hermes_home before a
later function-local 'from hermes_constants import get_hermes_home'
shadowed it → UnboundLocalError swallowed by the snapshot try/except,
silently disabling the post-snapshot check AND the snapshot-id output.
Alias the import explicitly.
- Import _quick_snapshot_root where used (was NameError in all 3 guards).
- tests/hermes_cli/test_state_db_guard.py: real-SQLite E2E coverage —
valid/zeroed/truncated files, oversized header gate, copy+verify
roundtrip, snapshot restore flow, and the live _run_pre_update_backup
path against a temp HERMES_HOME with mid-flight zeroing.
